86 results on '"Caslake, Muriel"'
Search Results
2. Interleukin-6 blockade raises LDL via reduced catabolism rather than via increased synthesis: a cytokine-specific mechanism for cholesterol changes in rheumatoid arthritis.
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Robertson J, Porter D, Sattar N, Packard CJ, Caslake M, McInnes I, and McCarey D
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- C-Reactive Protein analysis, Cholesterol blood, Cholesterol, HDL blood, Female, Humans, Interleukin-6 antagonists & inhibitors, Kinetics, Male, Middle Aged, Severity of Illness Index, Treatment Outcome, Antibodies, Monoclonal, Humanized pharmacokinetics, Antirheumatic Agents pharmacokinetics, Arthritis, Rheumatoid blood, Arthritis, Rheumatoid drug therapy, Cholesterol, LDL blood, Interleukin-6 metabolism
- Abstract
Objectives: Patients with rheumatoid arthritis (RA) have reduced serum low-density lipoprotein cholesterol (LDL-c), which increases following therapeutic IL-6 blockade. We aimed to define the metabolic pathways underlying these lipid changes., Methods: In the KALIBRA study, lipoprotein kinetic studies were performed on 11 patients with severe active RA at baseline and following three intravenous infusions of the IL-6R blocker tocilizumab. The primary outcome measure was the fractional catabolic rate (FCR) of LDL., Results: Serum total cholesterol (4.8 vs 5.7 mmol/L, p=0.003), LDL-c (2.9 vs 3.4 mmol/L, p=0.014) and high-density lipoprotein cholesterol (1.23 vs 1.52 mmol/L, p=0.006) increased following tocilizumab therapy. The LDL FCR fell from a state of hypercatabolism to a value approximating that of the normal population (0.53 vs 0.27 pools/day, p=0.006). Changes in FCR correlated tightly with changes in serum LDL-c and C-reactive protein but not Clinical Disease Activity Index., Conclusions: Patients with RA have low serum LDL-c due to hypercatabolism of LDL particles. IL-6 blockade normalises this catabolism in a manner associating with the acute phase response (and thus hepatic IL-6 signalling) but not with RA disease activity as measured clinically. We demonstrate that IL-6 is one of the key drivers of inflammation-driven dyslipidaemia., Competing Interests: Competing interests: IM, NS, DM, CP and DP have received honoraria from or provided consultancy services for Roche / Chugai. JR has received personal fees from Janssen outside the submitted work. MC reports no relevant conflicts of interest., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)
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- 2017
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3. Relationship between circulating microRNA-30c with total- and LDL-cholesterol, their circulatory transportation and effect of statins.
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Sodi R, Eastwood J, Caslake M, Packard CJ, and Denby L
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- Adult, Biological Transport, Cholesterol, LDL metabolism, Exosomes metabolism, Homeostasis, Humans, Lipids physiology, Lipoproteins, HDL3 metabolism, MicroRNAs metabolism, Pravastatin pharmacology, Rosuvastatin Calcium pharmacology, Cholesterol blood, Cholesterol, LDL blood, Hydroxymethylglutaryl-CoA Reductase Inhibitors pharmacology, MicroRNAs blood
- Abstract
Background: Small non-coding microRNAs (miR) have important regulatory roles and are used as biomarkers of disease. We investigated the relationship between lipoproteins and circulating miR-30c, evaluated how they are transported in circulation and determined whether statins altered the circulating concentration of miR-30c., Methods: To determine the relationship between lipoproteins and circulating miR-30c, serum samples from 79 subjects recruited from a lipid clinic were evaluated. Ultracentrifugation and nanoparticle tracking analysis was used to evaluate the transportation of miR-30c in the circulation by lipoproteins and extracellular vesicles in three healthy volunteers. Using archived samples from previous studies, the effects of 40mg rosuvastatin (n=22) and 40mg pravastatin (n=24) on miR-30c expression was also examined. RNA extraction, reverse transcription-quantitative real-time polymerase chain reaction was carried out using standard procedures., Results: When stratified according to total cholesterol concentration, there was increased miR-30c expression in the highest compared to the lowest tertile (p=0.035). There was significant positive correlation between miR-30c and total- (r=0.367; p=0.002) and LDL-cholesterol (r=0.391; p=0.001). We found that miR-30c was transported in both exosomes and on HDL3. There was a 3.8-fold increased expression of circulating miR-30c after pravastatin treatment for 1year (p=0.005) but no significant change with atorvastatin after 8weeks (p=0.145)., Conclusions: This study shows for the first-time in humans that circulating miR-30c is significantly, positively correlated with total- and LDL-cholesterol implicating regulatory functions in lipid homeostasis. We show miR-30c is transported in both exosomes and on HDL3 and pravastatin therapy significantly increased circulating miR-30c expression adding to the pleiotropic dimensions of statins., (Copyright © 2017 Elsevier B.V. All rights reserved.)
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- 2017
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4. Genetic invalidation of Lp-PLA 2 as a therapeutic target: Large-scale study of five functional Lp-PLA 2 -lowering alleles.
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Gregson JM, Freitag DF, Surendran P, Stitziel NO, Chowdhury R, Burgess S, Kaptoge S, Gao P, Staley JR, Willeit P, Nielsen SF, Caslake M, Trompet S, Polfus LM, Kuulasmaa K, Kontto J, Perola M, Blankenberg S, Veronesi G, Gianfagna F, Männistö S, Kimura A, Lin H, Reilly DF, Gorski M, Mijatovic V, Munroe PB, Ehret GB, Thompson A, Uria-Nickelsen M, Malarstig A, Dehghan A, Vogt TF, Sasaoka T, Takeuchi F, Kato N, Yamada Y, Kee F, Müller-Nurasyid M, Ferrières J, Arveiler D, Amouyel P, Salomaa V, Boerwinkle E, Thompson SG, Ford I, Wouter Jukema J, Sattar N, Packard CJ, Shafi Majumder AA, Alam DS, Deloukas P, Schunkert H, Samani NJ, Kathiresan S, Nordestgaard BG, Saleheen D, Howson JM, Di Angelantonio E, Butterworth AS, and Danesh J
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- 1-Alkyl-2-acetylglycerophosphocholine Esterase drug effects, 1-Alkyl-2-acetylglycerophosphocholine Esterase genetics, Adult, Aged, Alleles, Case-Control Studies, Coronary Disease diagnosis, Female, Gene Expression Regulation, Genotype, Humans, Male, Middle Aged, Polymorphism, Single Nucleotide, Randomized Controlled Trials as Topic, Reference Values, Reproducibility of Results, Risk Assessment, Treatment Outcome, Benzaldehydes therapeutic use, Coronary Disease drug therapy, Coronary Disease genetics, Molecular Targeted Therapy, Oximes therapeutic use, Phospholipase A2 Inhibitors therapeutic use
- Abstract
Aims Darapladib, a potent inhibitor of lipoprotein-associated phospholipase A
2 (Lp-PLA2 ), has not reduced risk of cardiovascular disease outcomes in recent randomized trials. We aimed to test whether Lp-PLA2 enzyme activity is causally relevant to coronary heart disease. Methods In 72,657 patients with coronary heart disease and 110,218 controls in 23 epidemiological studies, we genotyped five functional variants: four rare loss-of-function mutations (c.109+2T > C (rs142974898), Arg82His (rs144983904), Val279Phe (rs76863441), Gln287Ter (rs140020965)) and one common modest-impact variant (Val379Ala (rs1051931)) in PLA2G7, the gene encoding Lp-PLA2 . We supplemented de-novo genotyping with information on a further 45,823 coronary heart disease patients and 88,680 controls in publicly available databases and other previous studies. We conducted a systematic review of randomized trials to compare effects of darapladib treatment on soluble Lp-PLA2 activity, conventional cardiovascular risk factors, and coronary heart disease risk with corresponding effects of Lp-PLA2 -lowering alleles. Results Lp-PLA2 activity was decreased by 64% ( p = 2.4 × 10-25 ) with carriage of any of the four loss-of-function variants, by 45% ( p < 10-300 ) for every allele inherited at Val279Phe, and by 2.7% ( p = 1.9 × 10-12 ) for every allele inherited at Val379Ala. Darapladib 160 mg once-daily reduced Lp-PLA2 activity by 65% ( p < 10-300 ). Causal risk ratios for coronary heart disease per 65% lower Lp-PLA2 activity were: 0.95 (0.88-1.03) with Val279Phe; 0.92 (0.74-1.16) with carriage of any loss-of-function variant; 1.01 (0.68-1.51) with Val379Ala; and 0.95 (0.89-1.02) with darapladib treatment. Conclusions In a large-scale human genetic study, none of a series of Lp-PLA2 -lowering alleles was related to coronary heart disease risk, suggesting that Lp-PLA2 is unlikely to be a causal risk factor.- Published
- 2017
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5. High-Sensitivity Cardiac Troponin, Statin Therapy, and Risk of Coronary Heart Disease.
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Ford I, Shah AS, Zhang R, McAllister DA, Strachan FE, Caslake M, Newby DE, Packard CJ, and Mills NL
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- Coronary Disease epidemiology, Coronary Disease prevention & control, Electrocardiography drug effects, Humans, Incidence, Male, Middle Aged, Primary Prevention, Prognosis, Risk Factors, Scotland epidemiology, Survival Rate trends, Coronary Disease blood, Hydroxymethylglutaryl-CoA Reductase Inhibitors therapeutic use, Risk Assessment methods, Troponin I blood
- Abstract
Background: Cardiac troponin is an independent predictor of cardiovascular mortality in individuals without symptoms or signs of cardiovascular disease. The mechanisms for this association are uncertain, and a role for troponin testing in the prevention of coronary heart disease has yet to be established., Objectives: This study sought to determine whether troponin concentration could predict coronary events, be modified by statins, and reflect response to therapy in a primary prevention population., Methods: WOSCOPS (West of Scotland Coronary Prevention Study) randomized men with raised low-density lipoprotein cholesterol and no history of myocardial infarction to pravastatin 40 mg once daily or placebo for 5 years. Plasma cardiac troponin I concentration was measured with a high-sensitivity assay at baseline and at 1 year in 3,318 participants., Results: Baseline troponin was an independent predictor of myocardial infarction or death from coronary heart disease (hazard ratio [HR]: 2.3; 95% confidence interval [CI]: 1.4 to 3.7) for the highest (≥5.2 ng/l) versus lowest (≤3.1 ng/l) quarter of troponin (p < 0.001). There was a 5-fold greater reduction in coronary events when troponin concentrations decreased by more than a quarter, rather than increased by more than a quarter, for both placebo (HR: 0.29; 95% CI: 0.12 to 0.72 vs. HR: 1.95; 95% CI: 1.09 to 3.49; p < 0.001 for trend) and pravastatin (HR: 0.23; 95% CI: 0.10 to 0.53 vs. HR: 1.08; 95% CI: 0.53 to 2.21; p < 0.001 for trend). Pravastatin reduced troponin concentration by 13% (10% to 15%; placebo adjusted, p < 0.001) and doubled the number of men whose troponin fell more than a quarter (p < 0.001), which identified them as having the lowest risk for future coronary events (1.4% over 5 years)., Conclusions: Troponin concentration predicts coronary events, is reduced by statin therapy, and change at 1 year is associated with future coronary risk independent of cholesterol lowering. Serial troponin measurements have major potential to assess cardiovascular risk and monitor the impact of therapeutic interventions., (Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2016
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6. The association of circulating microRNA-30c with atherogenic lipoprotein subfractions and composition.
- Author
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Eastwood J, Caslake MJ, and Sodi R
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- Cross-Over Studies, Double-Blind Method, Humans, Phenotype, Atherosclerosis blood, Lipoproteins blood, MicroRNAs blood
- Abstract
Circulating miR-30c has been linked to various aspects of cholesterol homeostasis. The aim of this study was to determine the association of circulating miR-30c with the atherogenic lipoprotein subfractions. Samples from subjects who were given placebo (n=22) in a randomised, double-blind crossover study were used. Subjects were divided into non-atherogenic lipoprotein phenotype (Non-ALP; n=12; triglycerides <2.0mmol/L) and atherogenic lipoprotein phenotype (ALP; n=10; triglycerides ≥2.0mmol/L) groups. All lipid and lipoprotein measurements, RNA extraction and reverse transcription-quantitative real-time polymerase chain reaction were undertaken using standard procedures. Subjects with ALP weighed significantly more than their non-ALP counterparts (p=0.023). In the non-ALP group there was significant correlation between miR-30c and components within VLDL1, namely triglyceride which showed a negative association (p=0.035) whereas phospholipids and cholesterol-ester were both positively correlated (p=0.025 and 0.014, respectively). In contrast, in the ALP group there was a significant correlation between the expression of miR-30c and components within VLDL2, namely triglyceride, which was positively associated (p=0.013). This study reveals specificity with regards to the effect of miR-30c on VLDL subfractions based on the individual's lipoprotein phenotype and implicates roles for microsomal-triglyceride transfer-protein and cholesteryl-ester-transfer-protein in LDL and VLDL metabolism, respectively., (Copyright © 2016 Elsevier B.V. All rights reserved.)
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- 2016
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7. Trans-ancestry meta-analyses identify rare and common variants associated with blood pressure and hypertension.
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Surendran P, Drenos F, Young R, Warren H, Cook JP, Manning AK, Grarup N, Sim X, Barnes DR, Witkowska K, Staley JR, Tragante V, Tukiainen T, Yaghootkar H, Masca N, Freitag DF, Ferreira T, Giannakopoulou O, Tinker A, Harakalova M, Mihailov E, Liu C, Kraja AT, Fallgaard Nielsen S, Rasheed A, Samuel M, Zhao W, Bonnycastle LL, Jackson AU, Narisu N, Swift AJ, Southam L, Marten J, Huyghe JR, Stančáková A, Fava C, Ohlsson T, Matchan A, Stirrups KE, Bork-Jensen J, Gjesing AP, Kontto J, Perola M, Shaw-Hawkins S, Havulinna AS, Zhang H, Donnelly LA, Groves CJ, Rayner NW, Neville MJ, Robertson NR, Yiorkas AM, Herzig KH, Kajantie E, Zhang W, Willems SM, Lannfelt L, Malerba G, Soranzo N, Trabetti E, Verweij N, Evangelou E, Moayyeri A, Vergnaud AC, Nelson CP, Poveda A, Varga TV, Caslake M, de Craen AJ, Trompet S, Luan J, Scott RA, Harris SE, Liewald DC, Marioni R, Menni C, Farmaki AE, Hallmans G, Renström F, Huffman JE, Hassinen M, Burgess S, Vasan RS, Felix JF, Uria-Nickelsen M, Malarstig A, Reily DF, Hoek M, Vogt T, Lin H, Lieb W, Traylor M, Markus HF, Highland HM, Justice AE, Marouli E, Lindström J, Uusitupa M, Komulainen P, Lakka TA, Rauramaa R, Polasek O, Rudan I, Rolandsson O, Franks PW, Dedoussis G, Spector TD, Jousilahti P, Männistö S, Deary IJ, Starr JM, Langenberg C, Wareham NJ, Brown MJ, Dominiczak AF, Connell JM, Jukema JW, Sattar N, Ford I, Packard CJ, Esko T, Mägi R, Metspalu A, de Boer RA, van der Meer P, van der Harst P, Gambaro G, Ingelsson E, Lind L, de Bakker PI, Numans ME, Brandslund I, Christensen C, Petersen ER, Korpi-Hyövälti E, Oksa H, Chambers JC, Kooner JS, Blakemore AI, Franks S, Jarvelin MR, Husemoen LL, Linneberg A, Skaaby T, Thuesen B, Karpe F, Tuomilehto J, Doney AS, Morris AD, Palmer CN, Holmen OL, Hveem K, Willer CJ, Tuomi T, Groop L, Käräjämäki A, Palotie A, Ripatti S, Salomaa V, Alam DS, Shafi Majumder AA, Di Angelantonio E, Chowdhury R, McCarthy MI, Poulter N, Stanton AV, Sever P, Amouyel P, Arveiler D, Blankenberg S, Ferrières J, Kee F, Kuulasmaa K, Müller-Nurasyid M, Veronesi G, Virtamo J, Deloukas P, Elliott P, Zeggini E, Kathiresan S, Melander O, Kuusisto J, Laakso M, Padmanabhan S, Porteous D, Hayward C, Scotland G, Collins FS, Mohlke KL, Hansen T, Pedersen O, Boehnke M, Stringham HM, Frossard P, Newton-Cheh C, Tobin MD, Nordestgaard BG, Caulfield MJ, Mahajan A, Morris AP, Tomaszewski M, Samani NJ, Saleheen D, Asselbergs FW, Lindgren CM, Danesh J, Wain LV, Butterworth AS, Howson JM, and Munroe PB
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- Genetic Predisposition to Disease, Genome-Wide Association Study, Genotype, Humans, Blood Pressure genetics, Genetic Variation, Hypertension genetics
- Abstract
High blood pressure is a major risk factor for cardiovascular disease and premature death. However, there is limited knowledge on specific causal genes and pathways. To better understand the genetics of blood pressure, we genotyped 242,296 rare, low-frequency and common genetic variants in up to 192,763 individuals and used ∼155,063 samples for independent replication. We identified 30 new blood pressure- or hypertension-associated genetic regions in the general population, including 3 rare missense variants in RBM47, COL21A1 and RRAS with larger effects (>1.5 mm Hg/allele) than common variants. Multiple rare nonsense and missense variant associations were found in A2ML1, and a low-frequency nonsense variant in ENPEP was identified. Our data extend the spectrum of allelic variation underlying blood pressure traits and hypertension, provide new insights into the pathophysiology of hypertension and indicate new targets for clinical intervention., Competing Interests: Conflict of interests N. P. has received financial support from several pharmaceutical companies that manufacture either blood pressure lowering or lipid lowering agents, or both, and consultancy fees. S. K. has received Research Grant-Merck, Bayer, Aegerion; SAB-Catabasis, Regeneron Genetics Center, Merck, Celera; Equity-San Therapeutics, Catabasis; Consulting-Novartis, Aegerion, Bristol Myers-Squibb, Sanofi, AstraZeneca, Alnylam. P. Sever has received research awards from Pfizer Inc. A. Malarstig and M. Uria-Nickelsen are full time employees of Pfizer. D. Reily and M. Hoek are full time employees of Merck and co Inc. M.J. Caulfield is Chief Scientist for Genomics England a UK Government company. The authors declare no competing financial interest.
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- 2016
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8. miR-34a(-/-) mice are susceptible to diet-induced obesity.
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Lavery CA, Kurowska-Stolarska M, Holmes WM, Donnelly I, Caslake M, Collier A, Baker AH, and Miller AM
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- Adipose Tissue metabolism, Adipose Tissue, Brown metabolism, Adipose Tissue, White metabolism, Animals, Interleukin-10 metabolism, Liver metabolism, Macrophages metabolism, Mice, Mice, Inbred C57BL, Tumor Necrosis Factor-alpha metabolism, Diet, High-Fat, MicroRNAs metabolism, Obesity metabolism
- Abstract
Objective: MicroRNA (miR)-34a regulates inflammatory pathways, and increased transcripts have been observed in serum and subcutaneous adipose of subjects who have obesity and type 2 diabetes. Therefore, the role of miR-34a in adipose tissue inflammation and lipid metabolism in murine diet-induced obesity was investigated., Methods: Wild-type (WT) and miR-34a(-/-) mice were fed chow or high-fat diet (HFD) for 24 weeks. WT and miR-34a(-/-) bone marrow-derived macrophages were cultured in vitro with macrophage colony-stimulating factor (M-CSF). Brown and white preadipocytes were cultured from the stromal vascular fraction (SVF) of intrascapular brown and epididymal white adipose tissue (eWAT), with rosiglitazone., Results: HFD-fed miR-34a(-/-) mice were significantly heavier with a greater increase in eWAT weight than WT. miR-34a(-/-) eWAT had a smaller adipocyte area, which significantly increased with HFD. miR-34a(-/-) eWAT showed basal increases in Cd36, Hmgcr, Lxrα, Pgc1α, and Fasn. miR-34a(-/-) intrascapular brown adipose tissue had basal reductions in c/ebpα and c/ebpβ, with in vitro miR-34a(-/-) white adipocytes showing increased lipid content. An F4/80(high) macrophage population was present in HFD miR-34a(-/-) eWAT, with increased IL-10 transcripts and serum IL-5 protein. Finally, miR-34a(-/-) bone marrow-derived macrophages showed an ablated CXCL1 response to tumor necrosis factor-α., Conclusions: These findings suggest a multifactorial role of miR-34a in controlling susceptibility to obesity, by regulating inflammatory and metabolic pathways., (© 2016 The Obesity Society.)
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- 2016
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9. Towards onset prevention of cognition decline in adults with Down syndrome (The TOP-COG study): A pilot randomised controlled trial.
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Cooper SA, Ademola T, Caslake M, Douglas E, Evans J, Greenlaw N, Haig C, Hassiotis A, Jahoda A, McConnachie A, Morrison J, Ring H, Starr J, Stiles C, Sirisena C, and Sullivan F
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- Adult, Double-Blind Method, Female, Humans, Male, Middle Aged, Outcome Assessment, Health Care, Pilot Projects, Prospective Studies, Simvastatin therapeutic use, Cognitive Dysfunction prevention & control, Down Syndrome complications
- Abstract
Background: Dementia is very common in Down syndrome (trisomy 21) adults. Statins may slow brain amyloid β (Aβ, coded on chromosome 21) deposition and, therefore, delay Alzheimer disease onset. One prospective cohort study with Down syndrome adults found participants on statins had reduced risk of incident dementia, but there are no randomised controlled trials (RCTs) on this issue. Evidence is sparse on the best instruments to detect longitudinal cognitive decline in older Down syndrome adults., Methods: TOP-COG was a feasibility/pilot, double-blind RCT of 12 months simvastatin 40 mg versus placebo for the primary prevention of dementia in Alzheimer disease in Down syndrome adults aged 50 years or older. Group allocation was stratified by age, apolipoprotein E (APOE) ε4 allele status, and cholesterol level. Recruitment was from multiple general community sources over 12 months. Adults with dementia, or simvastatin contraindications, were excluded. Main outcomes were recruitment and retention rates. Cognitive decline was measured with a battery of tests; secondary measures were adaptive behaviour skills, general health, and quality of life. Assessments were conducted pre randomisation and at 12 months post randomisation. Blood Aβ40/Aβ42 levels were investigated as a putative biomarker. Results were analysed on an intention-to-treat basis. A qualitative sub-study was conducted and analysed using the Framework Approach to determine recruitment motivators/barriers, and participation experience., Results: We identified 181 (78 %) of the likely eligible Down syndrome population, and recruited 21 (11.6 %), from an area with a general population size of 3,135,974. Recruitment was highly labour-intensive. Thirteen (62 %) participants completed the full year. Results favoured the simvastatin group. The most appropriate cognitive instrument (regarding ease of completion and detecting change over time) was the Memory for Objects test from the Neuropsychological Assessment of Dementia in Individuals with Intellectual Disabilities battery. Cognitive testing appeared more sensitive than proxy-rated adaptive behaviour, quality of life, or general health scores. Aβ40 levels changed less for the simvastatin group (not statistically significant). People mostly declined to participate because of not wanting to take medication, and not knowing if they would receive simvastatin or placebo. Participants reported enjoying taking part., Conclusion: A full-scale RCT is feasible. It will need 37 % UK population coverage to recruit the required 160 participants. Information/education about the importance of RCT participation is needed for this population., Trial Registration: ISRCTN67338640 .
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- 2016
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10. A genomic approach to therapeutic target validation identifies a glucose-lowering GLP1R variant protective for coronary heart disease.
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Scott RA, Freitag DF, Li L, Chu AY, Surendran P, Young R, Grarup N, Stancáková A, Chen Y, Varga TV, Yaghootkar H, Luan J, Zhao JH, Willems SM, Wessel J, Wang S, Maruthur N, Michailidou K, Pirie A, van der Lee SJ, Gillson C, Al Olama AA, Amouyel P, Arriola L, Arveiler D, Aviles-Olmos I, Balkau B, Barricarte A, Barroso I, Garcia SB, Bis JC, Blankenberg S, Boehnke M, Boeing H, Boerwinkle E, Borecki IB, Bork-Jensen J, Bowden S, Caldas C, Caslake M, Cupples LA, Cruchaga C, Czajkowski J, den Hoed M, Dunn JA, Earl HM, Ehret GB, Ferrannini E, Ferrieres J, Foltynie T, Ford I, Forouhi NG, Gianfagna F, Gonzalez C, Grioni S, Hiller L, Jansson JH, Jørgensen ME, Jukema JW, Kaaks R, Kee F, Kerrison ND, Key TJ, Kontto J, Kote-Jarai Z, Kraja AT, Kuulasmaa K, Kuusisto J, Linneberg A, Liu C, Marenne G, Mohlke KL, Morris AP, Muir K, Müller-Nurasyid M, Munroe PB, Navarro C, Nielsen SF, Nilsson PM, Nordestgaard BG, Packard CJ, Palli D, Panico S, Peloso GM, Perola M, Peters A, Poole CJ, Quirós JR, Rolandsson O, Sacerdote C, Salomaa V, Sánchez MJ, Sattar N, Sharp SJ, Sims R, Slimani N, Smith JA, Thompson DJ, Trompet S, Tumino R, van der A DL, van der Schouw YT, Virtamo J, Walker M, Walter K, Abraham JE, Amundadottir LT, Aponte JL, Butterworth AS, Dupuis J, Easton DF, Eeles RA, Erdmann J, Franks PW, Frayling TM, Hansen T, Howson JM, Jørgensen T, Kooner J, Laakso M, Langenberg C, McCarthy MI, Pankow JS, Pedersen O, Riboli E, Rotter JI, Saleheen D, Samani NJ, Schunkert H, Vollenweider P, O'Rahilly S, Deloukas P, Danesh J, Goodarzi MO, Kathiresan S, Meigs JB, Ehm MG, Wareham NJ, and Waterworth DM
- Subjects
- Alleles, Diabetes Mellitus, Type 2 genetics, Dipeptidyl Peptidase 4 genetics, Genotype, Humans, Obesity genetics, Receptor, Cannabinoid, CB2 genetics, Receptor, Serotonin, 5-HT2C genetics, Receptors, Somatostatin genetics, Sodium-Glucose Transporter 1 genetics, Coronary Disease genetics, Glucagon-Like Peptide-1 Receptor genetics
- Abstract
Regulatory authorities have indicated that new drugs to treat type 2 diabetes (T2D) should not be associated with an unacceptable increase in cardiovascular risk. Human genetics may be able to guide development of antidiabetic therapies by predicting cardiovascular and other health endpoints. We therefore investigated the association of variants in six genes that encode drug targets for obesity or T2D with a range of metabolic traits in up to 11,806 individuals by targeted exome sequencing and follow-up in 39,979 individuals by targeted genotyping, with additional in silico follow-up in consortia. We used these data to first compare associations of variants in genes encoding drug targets with the effects of pharmacological manipulation of those targets in clinical trials. We then tested the association of those variants with disease outcomes, including coronary heart disease, to predict cardiovascular safety of these agents. A low-frequency missense variant (Ala316Thr; rs10305492) in the gene encoding glucagon-like peptide-1 receptor (GLP1R), the target of GLP1R agonists, was associated with lower fasting glucose and T2D risk, consistent with GLP1R agonist therapies. The minor allele was also associated with protection against heart disease, thus providing evidence that GLP1R agonists are not likely to be associated with an unacceptable increase in cardiovascular risk. Our results provide an encouraging signal that these agents may be associated with benefit, a question currently being addressed in randomized controlled trials. Genetic variants associated with metabolic traits and multiple disease outcomes can be used to validate therapeutic targets at an early stage in the drug development process., (Copyright © 2016, American Association for the Advancement of Science.)
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- 2016
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11. Accelerated ageing and renal dysfunction links lower socioeconomic status and dietary phosphate intake.
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McClelland R, Christensen K, Mohammed S, McGuinness D, Cooney J, Bakshi A, Demou E, MacDonald E, Caslake M, Stenvinkel P, and Shiels PG
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- Adult, DNA Methylation, Female, Humans, Hyperphosphatemia blood, Hyperphosphatemia physiopathology, Male, Middle Aged, Risk Factors, Telomere, Aging physiology, Diet, Kidney physiopathology, Phosphates blood, Social Class
- Abstract
Background: We have sought to explore the impact of dietary Pi intake on human age related health in the pSoBid cohort (n=666) to explain the disparity between health and deprivation status in this cohort. As hyperphosphataemia is a driver of accelerated ageing in rodent models of progeria we tested whether variation in Pi levels in man associate with measures of biological ageing and health., Results: We observed significant relationships between serum Pi levels and markers of biological age (telomere length (p=0.040) and DNA methylation content (p=0.028), gender and chronological age (p=0.032). When analyses were adjusted for socio-economic status and nutritional factors, associations were observed between accelerated biological ageing (telomere length, genomic methylation content) and dietary derived Pi levels among the most deprived males, directly related to the frequency of red meat consumption., Conclusions: Accelerated ageing is associated with high serum Pi levels and frequency of red meat consumption. Our data provide evidence for a mechanistic link between high intake of Pi and age-related morbidities tied to socio-economic status.
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- 2016
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12. Very Low-Calorie Diet and 6 Months of Weight Stability in Type 2 Diabetes: Pathophysiological Changes in Responders and Nonresponders.
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Steven S, Hollingsworth KG, Al-Mrabeh A, Avery L, Aribisala B, Caslake M, and Taylor R
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- Adult, Blood Glucose metabolism, Body Weight physiology, Diabetes Mellitus, Type 2 blood, Diabetes Mellitus, Type 2 diagnosis, Fasting blood, Female, Humans, Insulin blood, Longitudinal Studies, Male, Middle Aged, Treatment Outcome, Body Weight Maintenance, Caloric Restriction methods, Diabetes Mellitus, Type 2 diet therapy, Diet, Reducing methods
- Abstract
Objective: Type 2 diabetes mellitus (T2DM) is generally regarded as an irreversible chronic condition. Because a very low-calorie diet (VLCD) can bring about acute return to normal glucose control in some people with T2DM, this study tested the potential durability of this normalization. The underlying mechanisms were defined., Research Design and Methods: People with a T2DM duration of 0.5-23 years (n = 30) followed a VLCD for 8 weeks. All oral agents or insulins were stopped at baseline. Following a stepped return to isocaloric diet, a structured, individualized program of weight maintenance was provided. Glucose control, insulin sensitivity, insulin secretion, and hepatic and pancreas fat content were quantified at baseline, after return to isocaloric diet, and after 6 months to permit the primary comparison of change between post-weight loss and 6 months in responders. Responders were defined as achieving fasting blood glucose <7 mmol/L after return to isocaloric diet., Results: Weight fell (98.0 ± 2.6 to 83.8 ± 2.4 kg) and remained stable over 6 months (84.7 ± 2.5 kg). Twelve of 30 participants achieved fasting plasma glucose <7 mmol/L after return to isocaloric diet (responders), and 13 of 30 after 6 months. Responders had a shorter duration of diabetes and a higher initial fasting plasma insulin level. HbA1c fell from 7.1 ± 0.3 to 5.8 ± 0.2% (55 ± 4 to 40 ± 2 mmol/mol) in responders (P < 0.001) and from 8.4 ± 0.3 to 8.0 ± 0.5% (68 ± 3 to 64 ± 5 mmol/mol) in nonresponders, remaining constant at 6 months (5.9 ± 0.2 and 7.8 ± 0.3% [41 ± 2 and 62 ± 3 mmol/mol], respectively). The responders were characterized by return of first-phase insulin response., Conclusions: A robust and sustainable weight loss program achieved continuing remission of diabetes for at least 6 months in the 40% who responded to a VLCD by achieving fasting plasma glucose of <7 mmol/L. T2DM is a potentially reversible condition., (© 2016 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.)
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- 2016
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13. Does high-density lipoprotein protect vascular function in healthy pregnancy?
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Sulaiman WN, Caslake MJ, Delles C, Karlsson H, Mulder MT, Graham D, and Freeman DJ
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- Adaptation, Physiological, Animals, Apolipoprotein A-I blood, Blood Vessels physiopathology, Energy Metabolism, Female, Humans, Inflammation Mediators blood, Maternal-Fetal Exchange, Oxidative Stress, Placental Circulation, Pre-Eclampsia blood, Pre-Eclampsia physiopathology, Pre-Eclampsia prevention & control, Pregnancy, Pregnancy Complications, Cardiovascular blood, Pregnancy Complications, Cardiovascular physiopathology, Vasodilation, Blood Vessels metabolism, Lipoproteins, HDL blood, Pregnancy Complications, Cardiovascular prevention & control
- Abstract
The maternal adaptation to pregnancy includes hyperlipidaemia, oxidative stress and chronic inflammation. In non-pregnant individuals, these processes are usually associated with poor vascular function. However, maternal vascular function is enhanced in pregnancy. It is not understood how this is achieved in the face of the adverse metabolic and inflammatory environment. Research into cardiovascular disease demonstrates that plasma HDL (high-density lipoprotein), by merit of its functionality rather than its plasma concentration, exerts protective effects on the vascular endothelium. HDL has vasodilatory, antioxidant, anti-thrombotic and anti-inflammatory effects, and can protect against endothelial cell damage. In pregnancy, the plasma HDL concentration starts to rise at 10 weeks of gestation, peaking at 20 weeks. The initial rise in plasma HDL occurs around the time of the establishment of the feto-placental circulation, a time when the trophoblast plugs in the maternal spiral arteries are released, generating oxidative stress. Thus there is the intriguing possibility that new HDL of improved function is synthesized around the time of the establishment of the feto-placental circulation. In obese pregnancy and, to a greater extent, in pre-eclampsia, plasma HDL levels are significantly decreased and maternal vascular function is reduced. Wire myography studies have shown an association between the plasma content of apolipoprotein AI, the major protein constituent of HDL, and blood vessel relaxation. These observations lead us to hypothesize that HDL concentration, and function, increases in pregnancy in order to protect the maternal vascular endothelium and that in pre-eclampsia this fails to occur., (© 2016 Authors; published by Portland Press Limited.)
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- 2016
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14. Consumption of Fish Oil Providing Amounts of Eicosapentaenoic Acid and Docosahexaenoic Acid That Can Be Obtained from the Diet Reduces Blood Pressure in Adults with Systolic Hypertension: A Retrospective Analysis.
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Minihane AM, Armah CK, Miles EA, Madden JM, Clark AB, Caslake MJ, Packard CJ, Kofler BM, Lietz G, Curtis PJ, Mathers JC, Williams CM, and Calder PC
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- Adult, Body Mass Index, Cross-Over Studies, Diet, Docosahexaenoic Acids blood, Double-Blind Method, E-Selectin blood, Eicosapentaenoic Acid blood, Female, Fish Oils blood, Humans, Intercellular Adhesion Molecule-1 blood, Male, Middle Aged, Nitric Oxide Synthase Type III genetics, P-Selectin blood, Retrospective Studies, United Kingdom, Vascular Cell Adhesion Molecule-1 blood, Blood Pressure drug effects, Docosahexaenoic Acids administration & dosage, Eicosapentaenoic Acid administration & dosage, Fish Oils administration & dosage, Hypertension blood
- Abstract
Background: Although many randomized controlled trials (RCTs) have examined the effects of the n-3 (ω-3) fatty acids eicosapentaenoic acid (EPA; 20:5n-3) and docosahexaenoic acid (DHA; 22:6n-3) on blood pressure (BP) and vascular function, the majority have used doses of EPA+DHA of >3 g/d, which are unlikely to be achieved by dietary manipulation., Objective: The objective was to examine, by using a retrospective analysis from a multicenter RCT, the impact of recommended EPA+DHA intakes achievable through diet on systolic and diastolic BPs and microvascular function in adults in the United Kingdom., Methods: In a double-blind, placebo-controlled RCT, healthy men and women (n = 312) consumed a control oil or fish oil (FO) providing 0.7 or 1.8 g EPA+DHA/d, in random order, each for 8 wk. Fasting BP and microvascular function (using laser Doppler iontophoresis) were assessed and plasma collected for the quantification of markers of vascular function. Participants were retrospectively genotyped for the endothelial nitric oxide synthase (eNOS) rs1799983 variant., Results: No effects of n-3 fatty acid treatment or any treatment × eNOS genotype interactions were evident in the group as a whole for any of the clinical or biochemical outcomes. Assessment of response according to hypertension status at baseline indicated a significant (P = 0.046) FO-induced reduction (mean: 5 mm Hg) in systolic BP, specifically in those with isolated systolic hypertension (n = 31). No dose response was observed., Conclusions: These findings indicate that in adults with isolated systolic hypertension, daily doses of EPA+DHA as low as 0.7 g show clinically meaningful BP reductions, which, at a population level, could be associated with lower cardiovascular disease risk. Confirmation of findings in an RCT in which participants are prospectively recruited on the basis of BP status is required to draw definite conclusions., (© 2016 American Society for Nutrition.)
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- 2016
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15. Moderate Exercise Increases Affinity of Large Very Low-Density Lipoproteins for Hydrolysis by Lipoprotein Lipase.
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Ghafouri K, Cooney J, Bedford DK, Wilson J, Caslake MJ, and Gill JM
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- Adult, Cross-Over Studies, Exercise Test, Humans, Hydrolysis, Lipid Metabolism physiology, Male, Middle Aged, Obesity metabolism, Overweight metabolism, Substrate Specificity, Young Adult, Exercise physiology, Lipoprotein Lipase metabolism, Lipoproteins, VLDL metabolism
- Abstract
Context: Postprandial triglyceride (TG) concentration is independently associated with cardiovascular disease risk. Exercise reduces postprandial TG concentrations, but the mechanisms responsible are unclear., Objective: The objective was to determine the effects of exercise on affinity of chylomicrons, large very low-density lipoproteins (VLDL1), and smaller VLDL (VLDL2) for lipoprotein lipase (LPL)-mediated TG hydrolysis., Design: This was designed as a within-participant crossover study., Setting: The setting was a university metabolic investigation unit., Participants: Participants were 10 overweight/obese men., Interventions: Participants undertook two oral fat tolerance tests, separated by 7-14 days, in which they had blood taken while fasting and for 4 hours after a high-fat mixed meal. On the afternoon before one test, they performed a 90-minute treadmill walk at 50% maximal oxygen uptake (exercise trial [EX]); no exercise was performed before the control trial (CON)., Main Outcome Measures: We measured circulating TG-rich lipoprotein concentrations and affinity of chylomicrons, VLDL1, and VLDL2 for LPL-mediated TG hydrolysis., Results: Exercise significantly reduced fasting VLDL1-TG concentration (CON, 0.49 [0.33-0.72] mmol.L(-1); EX, 0.36 [0.22-0.59] mmol.L(-1); geometric means [95% confidence interval]; P = .04). Time-averaged postprandial chylomicron-TG (CON, 0.55 ± 0.10 mmol.L(-1); EX, 0.39 ± 0.08 mmol.L(-1); mean ± SEM; P = .03) and VLDL1-TG (CON, 0.85 ± 0.13 mmol.L(-1); EX, 0.66 ± 0.10 mmol.L(-1); P = .01) concentrations were both lower in EX than CON. Affinity of VLDL1 for LPL-mediated TG hydrolysis increased by 2.2 (1.3-3.7)-fold [geometric mean (95% confidence interval)] (P = .02) in the fasted state and 2.6 (1.8-2.6)-fold (P = .001) postprandially. Affinity of chylomicrons and VLDL2 was not significantly different between trials., Conclusions: Exercise increases affinity of VLDL1 for LPL-mediated TG hydrolysis both fasting and postprandially. This mechanism is likely to contribute to the TG-lowering effect of exercise.
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- 2015
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16. Antioxidant properties of amniotic membrane: novel observations from a pilot study.
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Lockington D, Agarwal P, Young D, Caslake M, and Ramaesh K
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- Amnion drug effects, Humans, Hydrogen Peroxide pharmacology, Oxidants pharmacology, Pilot Projects, Reactive Oxygen Species metabolism, Amnion physiology, Antioxidants metabolism, Free Radical Scavengers metabolism
- Abstract
Objective: Amniotic membrane (AM) is used to manage various debilitated ocular surface conditions. The impact of oxidative stress and free radicals on the ocular surface is increasingly being recognized. Hyaluronic acid (HA) has anti-inflammatory properties and is abundantly present in AM. In this in vitro pilot study, we investigated the potential of AM for intrinsic free radical scavenging properties., Methods: Strips of AM were incubated in sealed tubes with hydrogen peroxide (H2O2). After being sonicated, uptake of reactive oxygen species (ROS) was measured by the Amplex Red Hydrogen Peroxide/Peroxidase assay. For comparison, 1630 kDA HA was used., Results: There was uptake of ROS by all AM samples, which decreased with increasing concentrations of H2O2. Mean ROS uptake for 5 different AMs at 1 hour was significantly greater for 50 μM (83%; SD 11.7, SEM 5.23) compared with 100 μM (67%; SD 20.48, SEM 9.16; p = 0.028; 95% CI 2.8-29.2). The HA comparison group showed similar uptake and trend., Conclusion: This pilot study demonstrates that AM is able to remove ROS from its environment. Demonstrating total antioxidant capacity in AM provides evidence for use as a free radical scavenger. The antioxidant properties of AM and the contribution from HA require more research., (Copyright © 2014 Canadian Ophthalmological Society. Published by Elsevier Inc. All rights reserved.)
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- 2014
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17. Toward onset prevention of cognitive decline in adults with Down syndrome (the TOP-COG study): study protocol for a randomized controlled trial.
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Cooper SA, Caslake M, Evans J, Hassiotis A, Jahoda A, McConnachie A, Morrison J, Ring H, Starr J, Stiles C, and Sullivan F
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- Age of Onset, Feasibility Studies, Humans, Hypolipidemic Agents administration & dosage, Hypolipidemic Agents adverse effects, Middle Aged, Neuropsychological Tests, Pilot Projects, Primary Prevention methods, Qualitative Research, Research Design, Simvastatin adverse effects, Alzheimer Disease drug therapy, Alzheimer Disease etiology, Alzheimer Disease prevention & control, Cognition Disorders drug therapy, Cognition Disorders etiology, Cognition Disorders prevention & control, Down Syndrome complications, Down Syndrome drug therapy, Simvastatin administration & dosage
- Abstract
Background: Early-onset dementia is common in Down syndrome adults, who have trisomy 21. The amyloid precursor protein gene is on chromosome 21, and so is over-expressed in Down syndrome, leading to amyloid β (Aβ) over-production, a major upstream pathway leading to Alzheimer disease (AD). Statins (microsomal 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors), have pleiotropic effects including potentially increasing brain amyloid clearance, making them plausible agents to reduce AD risk. Animal models, human observational studies, and small scale trials support this rationale, however, there are no AD primary prevention trials in Down syndrome adults. In this study we study aim to inform the design of a full-scale primary prevention trial., Methods/design: TOP-COG is a feasibility and pilot double-blind randomized controlled trial (RCT), with a nested qualitative study, conducted in the general community. About 60 Down syndrome adults, aged ≥50 will be included. The intervention is oral simvastatin 40 mg at night for 12 months, versus placebo. The primary endpoint is recruitment and retention rates. Secondary endpoints are (1) tolerability and safety; (2) detection of the most sensitive neurocognitive instruments; (3) perceptions of Down syndrome adults and caregivers on whether to participate, and assessment experiences; (4) distributions of cognitive decline, adaptive behavior, general health/quality of life, service use, caregiver strain, and sample size implications; (5) whether Aβ42/Aβ40 is a cognitive decline biomarker. We will describe percentages recruited from each source, the number of contacts to achieve this, plus recruitment rate by general population size. We will calculate summary statistics with 90% confidence limits where appropriate, for each study outcome as a whole, by treatment group and in relation to baseline age, cognitive function, cholesterol and other characteristics. Changes over time will be summarized graphically. The sample size for a definitive RCT will be estimated under alternative assumptions., Discussion: This study is important, as AD is a major problem for Down syndrome adults, for whom there are currently no effective preventions or treatments. It will also delineate the most suitable assessment instruments for this population. Recruitment of intellectually disabled adults is notoriously difficult, and we shall provide valuable information on this, informing future studies., Trial Registration: Current Controlled Trials ISRCTN Register ID: ISRCTN67338640 (17 November 2011).
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- 2014
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18. CD36 and SR-BI are involved in cellular uptake of provitamin A carotenoids by Caco-2 and HEK cells, and some of their genetic variants are associated with plasma concentrations of these micronutrients in humans.
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Borel P, Lietz G, Goncalves A, Szabo de Edelenyi F, Lecompte S, Curtis P, Goumidi L, Caslake MJ, Miles EA, Packard C, Calder PC, Mathers JC, Minihane AM, Tourniaire F, Kesse-Guyot E, Galan P, Hercberg S, Breidenassel C, González Gross M, Moussa M, Meirhaeghe A, and Reboul E
- Subjects
- Adolescent, Caco-2 Cells, Cross-Sectional Studies, Cryptoxanthins, Female, Genetic Variation, Genotype, HEK293 Cells, Humans, Male, Polymorphism, Single Nucleotide genetics, Sex Factors, Vitamin A metabolism, Xanthophylls blood, Xanthophylls metabolism, beta Carotene blood, beta Carotene metabolism, CD36 Antigens genetics, CD36 Antigens physiology, Carotenoids blood, Carotenoids metabolism, Scavenger Receptors, Class B genetics, Scavenger Receptors, Class B physiology
- Abstract
Scavenger receptor class B type I (SR-BI) and cluster determinant 36 (CD36) have been involved in cellular uptake of some provitamin A carotenoids. However, data are incomplete (e.g., there are no data on α-carotene), and it is not known whether genetic variants in their encoding genes can affect provitamin A carotenoid status. The objectives were 1) to assess the involvement of these scavenger receptors in cellular uptake of the main provitamin A carotenoids (i.e., β-carotene, α-carotene, and β-cryptoxanthin) as well as that of preformed vitamin A (i.e., retinol) and 2) to investigate the contribution of genetic variations in genes encoding these proteins to interindividual variations in plasma concentrations of provitamin A carotenoids. The involvement of SR-BI and CD36 in carotenoids and retinol cellular uptake was investigated in Caco-2 and human embryonic kidney (HEK) cell lines. The involvement of scavenger receptor class B type I (SCARB1) and CD36 genetic variants on plasma concentrations of provitamin A carotenoids was assessed by association studies in 3 independent populations. Cell experiments suggested the involvement of both proteins in cellular uptake of provitamin A carotenoids but not in that of retinol. Association studies showed that several plasma provitamin A carotenoid concentrations were significantly different (P < 0.0083) between participants who bore different genotypes at single nucleotide polymorphisms and haplotypes in CD36 and SCARB1. In conclusion, SR-BI and CD36 are involved in cellular uptake of provitamin A carotenoids, and genetic variations in their encoding genes may modulate plasma concentrations of provitamin A carotenoids at a population level.
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- 2013
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19. Genetic associations with valvular calcification and aortic stenosis.
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Thanassoulis G, Campbell CY, Owens DS, Smith JG, Smith AV, Peloso GM, Kerr KF, Pechlivanis S, Budoff MJ, Harris TB, Malhotra R, O'Brien KD, Kamstrup PR, Nordestgaard BG, Tybjaerg-Hansen A, Allison MA, Aspelund T, Criqui MH, Heckbert SR, Hwang SJ, Liu Y, Sjogren M, van der Pals J, Kälsch H, Mühleisen TW, Nöthen MM, Cupples LA, Caslake M, Di Angelantonio E, Danesh J, Rotter JI, Sigurdsson S, Wong Q, Erbel R, Kathiresan S, Melander O, Gudnason V, O'Donnell CJ, and Post WS
- Subjects
- Aged, Aortic Valve diagnostic imaging, Aortic Valve Stenosis diagnostic imaging, Aortic Valve Stenosis ethnology, Female, Genome-Wide Association Study, Heart Valve Diseases diagnostic imaging, Heart Valve Diseases ethnology, Humans, Linear Models, Male, Mendelian Randomization Analysis, Middle Aged, Mitral Valve diagnostic imaging, Mitral Valve pathology, Tomography, X-Ray Computed, Aortic Valve pathology, Aortic Valve Stenosis genetics, Calcinosis genetics, Heart Valve Diseases genetics, Lipoprotein(a) genetics, Polymorphism, Single Nucleotide
- Abstract
Background: Limited information is available regarding genetic contributions to valvular calcification, which is an important precursor of clinical valve disease., Methods: We determined genomewide associations with the presence of aortic-valve calcification (among 6942 participants) and mitral annular calcification (among 3795 participants), as detected by computed tomographic (CT) scanning; the study population for this analysis included persons of white European ancestry from three cohorts participating in the Cohorts for Heart and Aging Research in Genomic Epidemiology consortium (discovery population). Findings were replicated in independent cohorts of persons with either CT-detected valvular calcification or clinical aortic stenosis., Results: One SNP in the lipoprotein(a) (LPA) locus (rs10455872) reached genomewide significance for the presence of aortic-valve calcification (odds ratio per allele, 2.05; P=9.0×10(-10)), a finding that was replicated in additional white European, African-American, and Hispanic-American cohorts (P<0.05 for all comparisons). Genetically determined Lp(a) levels, as predicted by LPA genotype, were also associated with aortic-valve calcification, supporting a causal role for Lp(a). In prospective analyses, LPA genotype was associated with incident aortic stenosis (hazard ratio per allele, 1.68; 95% confidence interval [CI], 1.32 to 2.15) and aortic-valve replacement (hazard ratio, 1.54; 95% CI, 1.05 to 2.27) in a large Swedish cohort; the association with incident aortic stenosis was also replicated in an independent Danish cohort. Two SNPs (rs17659543 and rs13415097) near the proinflammatory gene IL1F9 achieved genomewide significance for mitral annular calcification (P=1.5×10(-8) and P=1.8×10(-8), respectively), but the findings were not replicated consistently., Conclusions: Genetic variation in the LPA locus, mediated by Lp(a) levels, is associated with aortic-valve calcification across multiple ethnic groups and with incident clinical aortic stenosis. (Funded by the National Heart, Lung, and Blood Institute and others.).
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- 2013
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20. Maternal obesity is associated with the formation of small dense LDL and hypoadiponectinemia in the third trimester.
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Meyer BJ, Stewart FM, Brown EA, Cooney J, Nilsson S, Olivecrona G, Ramsay JE, Griffin BA, Caslake MJ, and Freeman DJ
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- Adiponectin blood, Adiponectin deficiency, Adult, Female, Humans, Metabolism, Inborn Errors blood, Obesity blood, Pregnancy, Triglycerides blood, Cholesterol, LDL blood, Lipoproteins, LDL blood, Metabolism, Inborn Errors complications, Obesity complications, Pregnancy Complications blood, Pregnancy Trimester, Third blood
- Abstract
Context: Maternal obesity is associated with high plasma triglyceride, poor vascular function, and an increased risk for pregnancy complications. In normal-weight pregnant women, higher triglyceride is associated with increased small, dense low-density lipoprotein (LDL)., Hypothesis: In obese pregnancy, increased plasma triglyceride concentrations result in triglyceride enrichment of very low-density lipoprotein-1 particles and formation of small dense LDL via lipoprotein lipase., Design: Women (n = 55) of body mass index of 18-46 kg/m(2) were sampled longitudinally at 12, 26, and 35 weeks' gestation and 4 months postnatally., Setting: Women were recruited at hospital antenatal appointments, and study visits were in a clinical research suite., Outcome Measures: Plasma concentrations of lipids, triglyceride-rich lipoproteins, lipoprotein lipase mass, estradiol, steroid hormone binding globulin, insulin, glucose, leptin, and adiponectin were determined., Results: Obese women commenced pregnancy with higher plasma triglyceride, reached the same maximum, and then returned to higher postnatal levels than normal-weight women. Estradiol response to pregnancy (trimester 1-3 incremental area under the curve) was positively associated with plasma triglyceride response (r(2) adjusted 25%, P < .001). In the third trimester, the proportion of small, dense LDL was 2-fold higher in obese women than normal-weight women [mean (SD) 40.7 (18.8) vs 21.9 (10.9)%, P = .014], and 35% of obese, 14% of overweight, and none of the normal-weight women displayed an atherogenic LDL subfraction phenotype. The small, dense LDL mass response to pregnancy was inversely associated with adiponectin response (17%, P = .013)., Conclusions: Maternal obesity is associated with an atherogenic LDL subfraction phenotype and may provide a mechanistic link to poor vascular function and adverse pregnancy outcome.
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- 2013
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21. C-reactive protein, fibrinogen, and cardiovascular disease prediction.
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Kaptoge S, Di Angelantonio E, Pennells L, Wood AM, White IR, Gao P, Walker M, Thompson A, Sarwar N, Caslake M, Butterworth AS, Amouyel P, Assmann G, Bakker SJ, Barr EL, Barrett-Connor E, Benjamin EJ, Björkelund C, Brenner H, Brunner E, Clarke R, Cooper JA, Cremer P, Cushman M, Dagenais GR, D'Agostino RB Sr, Dankner R, Davey-Smith G, Deeg D, Dekker JM, Engström G, Folsom AR, Fowkes FG, Gallacher J, Gaziano JM, Giampaoli S, Gillum RF, Hofman A, Howard BV, Ingelsson E, Iso H, Jørgensen T, Kiechl S, Kitamura A, Kiyohara Y, Koenig W, Kromhout D, Kuller LH, Lawlor DA, Meade TW, Nissinen A, Nordestgaard BG, Onat A, Panagiotakos DB, Psaty BM, Rodriguez B, Rosengren A, Salomaa V, Kauhanen J, Salonen JT, Shaffer JA, Shea S, Ford I, Stehouwer CD, Strandberg TE, Tipping RW, Tosetto A, Wassertheil-Smoller S, Wennberg P, Westendorp RG, Whincup PH, Wilhelmsen L, Woodward M, Lowe GD, Wareham NJ, Khaw KT, Sattar N, Packard CJ, Gudnason V, Ridker PM, Pepys MB, Thompson SG, and Danesh J
- Subjects
- Adult, Biomarkers blood, Cardiovascular Diseases blood, Cohort Studies, Female, Humans, Lipids blood, Male, Mass Screening, Middle Aged, Practice Guidelines as Topic, Prognosis, Proportional Hazards Models, Risk Factors, C-Reactive Protein metabolism, Cardiovascular Diseases prevention & control, Fibrinogen metabolism
- Abstract
Background: There is debate about the value of assessing levels of C-reactive protein (CRP) and other biomarkers of inflammation for the prediction of first cardiovascular events., Methods: We analyzed data from 52 prospective studies that included 246,669 participants without a history of cardiovascular disease to investigate the value of adding CRP or fibrinogen levels to conventional risk factors for the prediction of cardiovascular risk. We calculated measures of discrimination and reclassification during follow-up and modeled the clinical implications of initiation of statin therapy after the assessment of CRP or fibrinogen., Results: The addition of information on high-density lipoprotein cholesterol to a prognostic model for cardiovascular disease that included age, sex, smoking status, blood pressure, history of diabetes, and total cholesterol level increased the C-index, a measure of risk discrimination, by 0.0050. The further addition to this model of information on CRP or fibrinogen increased the C-index by 0.0039 and 0.0027, respectively (P<0.001), and yielded a net reclassification improvement of 1.52% and 0.83%, respectively, for the predicted 10-year risk categories of "low" (<10%), "intermediate" (10% to <20%), and "high" (≥20%) (P<0.02 for both comparisons). We estimated that among 100,000 adults 40 years of age or older, 15,025 persons would initially be classified as being at intermediate risk for a cardiovascular event if conventional risk factors alone were used to calculate risk. Assuming that statin therapy would be initiated in accordance with Adult Treatment Panel III guidelines (i.e., for persons with a predicted risk of ≥20% and for those with certain other risk factors, such as diabetes, irrespective of their 10-year predicted risk), additional targeted assessment of CRP or fibrinogen levels in the 13,199 remaining participants at intermediate risk could help prevent approximately 30 additional cardiovascular events over the course of 10 years., Conclusions: In a study of people without known cardiovascular disease, we estimated that under current treatment guidelines, assessment of the CRP or fibrinogen level in people at intermediate risk for a cardiovascular event could help prevent one additional event over a period of 10 years for every 400 to 500 people screened. (Funded by the British Heart Foundation and others.).
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- 2012
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22. Normal levels of inflammatory markers in treated patients with familial hypercholesterolaemia: a cross-sectional study.
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Seed M, Betteridge DJ, Cooper J, Caslake M, Durrington PN, Thompson GR, Sattar N, Humphries SE, and Neil HA
- Abstract
Objective: To assess the relationship of levels of inflammatory risk markers to presence of clinical coronary artery disease (CAD) in patients with treated heterozygous familial hypercholesterolaemia., Design: A cross-sectional study of patients on the Simon Broome Familial Hyperlipidaemia Register., Setting: Six hospital outpatient clinics in the UK., Participants: A total of 211 men and 199 women with heterozygous familial hypercholesterolaemia., Main Outcome Measures: Analysis of conventional risk factors and concentrations of high-sensitivity C-reactive protein (hsCRP), lipoprotein(a), serum intercellular adhesion molecule (sICAM), interleukin-6 (IL-6) and lipoprotein-associated phospholipase A2 (LpPLA2) mass., Results: CAD was present in 104 men and in 55 women; the mean ages of onset were 43.1 and 46.5 years, respectively. On univariate analysis there was a positive relationship of CAD with age, male sex, smoking, IL-6 and sICAM, and an inverse relationship with low-density lipoprotein (LDL) and LpPLA2. On multivariate analysis, age, smoking, low LDL and low LpPLA2 were associated with CAD. When LpPLA2 values were adjusted for apoB and aspirin usage, there was no significant difference between those with and without CAD. Only age and smoking were independently associated with CAD in men, and IL-6 and lipoprotein(a) in women., Conclusions: Although on univariate analysis inflammatory marker levels were associated with CAD in these patients, the majority of the associations, including that for hsCRP, disappeared when corrected for smoking and apoB. This may be because atherosclerotic plaques in these statin-treated patients were quiescent or an effect of aspirin usage. In this observational study newer risk markers were not usefully associated with the presence or absence of symptomatic CAD.
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- 2012
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23. Lipid-related markers and cardiovascular disease prediction.
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Di Angelantonio E, Gao P, Pennells L, Kaptoge S, Caslake M, Thompson A, Butterworth AS, Sarwar N, Wormser D, Saleheen D, Ballantyne CM, Psaty BM, Sundström J, Ridker PM, Nagel D, Gillum RF, Ford I, Ducimetiere P, Kiechl S, Koenig W, Dullaart RP, Assmann G, D'Agostino RB Sr, Dagenais GR, Cooper JA, Kromhout D, Onat A, Tipping RW, Gómez-de-la-Cámara A, Rosengren A, Sutherland SE, Gallacher J, Fowkes FG, Casiglia E, Hofman A, Salomaa V, Barrett-Connor E, Clarke R, Brunner E, Jukema JW, Simons LA, Sandhu M, Wareham NJ, Khaw KT, Kauhanen J, Salonen JT, Howard WJ, Nordestgaard BG, Wood AM, Thompson SG, Boekholdt SM, Sattar N, Packard C, Gudnason V, and Danesh J
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- Aged, Cholesterol, HDL blood, Cohort Studies, Female, Humans, Male, Middle Aged, Risk Assessment, Biomarkers blood, Cardiovascular Diseases blood, Cardiovascular Diseases epidemiology, Lipoproteins blood
- Abstract
Context: The value of assessing various emerging lipid-related markers for prediction of first cardiovascular events is debated., Objective: To determine whether adding information on apolipoprotein B and apolipoprotein A-I, lipoprotein(a), or lipoprotein-associated phospholipase A2 to total cholesterol and high-density lipoprotein cholesterol (HDL-C) improves cardiovascular disease (CVD) risk prediction., Design, Setting, and Participants: Individual records were available for 165,544 participants without baseline CVD in 37 prospective cohorts (calendar years of recruitment: 1968-2007) with up to 15,126 incident fatal or nonfatal CVD outcomes (10,132 CHD and 4994 stroke outcomes) during a median follow-up of 10.4 years (interquartile range, 7.6-14 years)., Main Outcome Measures: Discrimination of CVD outcomes and reclassification of participants across predicted 10-year risk categories of low (<10%), intermediate (10%-<20%), and high (≥20%) risk., Results: The addition of information on various lipid-related markers to total cholesterol, HDL-C, and other conventional risk factors yielded improvement in the model's discrimination: C-index change, 0.0006 (95% CI, 0.0002-0.0009) for the combination of apolipoprotein B and A-I; 0.0016 (95% CI, 0.0009-0.0023) for lipoprotein(a); and 0.0018 (95% CI, 0.0010-0.0026) for lipoprotein-associated phospholipase A2 mass. Net reclassification improvements were less than 1% with the addition of each of these markers to risk scores containing conventional risk factors. We estimated that for 100,000 adults aged 40 years or older, 15,436 would be initially classified at intermediate risk using conventional risk factors alone. Additional testing with a combination of apolipoprotein B and A-I would reclassify 1.1%; lipoprotein(a), 4.1%; and lipoprotein-associated phospholipase A2 mass, 2.7% of people to a 20% or higher predicted CVD risk category and, therefore, in need of statin treatment under Adult Treatment Panel III guidelines., Conclusion: In a study of individuals without known CVD, the addition of information on the combination of apolipoprotein B and A-I, lipoprotein(a), or lipoprotein-associated phospholipase A2 mass to risk scores containing total cholesterol and HDL-C led to slight improvement in CVD prediction.
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- 2012
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24. The effect of omega-3 fatty acids on the atherogenic lipoprotein phenotype in patients with nephrotic range proteinuria.
- Author
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Bell S, Cooney J, Packard CJ, Caslake MJ, and Deighan CJ
- Subjects
- Aged, Atherosclerosis blood, Atherosclerosis complications, Biomarkers blood, Drug Combinations, Female, Humans, Male, Middle Aged, Nephrosis blood, Nephrosis complications, Phenotype, Proteinuria blood, Proteinuria complications, Scotland, Time Factors, Treatment Outcome, Atherosclerosis drug therapy, Dietary Supplements, Docosahexaenoic Acids therapeutic use, Eicosapentaenoic Acid therapeutic use, Hypolipidemic Agents therapeutic use, Lipoproteins blood, Nephrosis drug therapy, Proteinuria drug therapy
- Abstract
Aims: Patients with nephrotic range proteinuria are known to have an increased risk of cardiovascular disease partly due to possessing the atherogenic lipoprotein phenotype. The aim of this study was to examine the effect of high dose omega-3 fatty acids on atherogenic triglyceride rich lipoproteins in patients with nephrotic range proteinuria, comparing their effect on lipoprotein profiles in age and sex matched controls., Methods: 17 patients with nephrotic range proteinuria and 17 age and sex matched controls were studied. Fasting lipids and lipoproteins were measured before and after 8 weeks treatment with 4 g daily of omega-3 fatty acids (Omacor®)., Results: In patients with proteinuria treatment reduced plasma triglyceride by a mean of 0.45 mmol/l (95%CI 0.16 - 0.74, p = 0.005) and plasma very low density lipoprotein cholesterol by a mean of 0.38 (95%CI 0.01 - 0.75, p = 0.04). LDL III concentration fell from 178.8 mg/dl (61.6 - 231.0) to 96.1 mg/dl (49.3 - 204.5), p = 0.05. In patients treatment altered the LDL profile so that LDLIII which was the major subfraction present at baseline was reduced from 49.9% to 29.8% (p = 0.01). Remnant lipoproteins (RLP) also fell with a mean reduction of 3.5 mg/dl in RLP-Cholesterol (95%CI 0.1 - 6.9, p = 0.05) and 12.4 mg/dl in RLP-triglyceride (95%CI 2.6 - 22.2, p = 0.03). There was however a 0.6 mmol/l rise in LDL-C (p = 0.06) in the patients. Treatment did not alter HDL-C., Conclusion: In patients with nephrotic range proteinuria, omega-3 fatty acids reduced triglyceride rich lipoproteins, LDL III and remnant lipoproteins. A tendency to an increase in LDL-C was observed but this was offset by an alteration in the distribution of the LDL profile towards lighter, larger LDL particles. We propose that treatment with omega-3 fatty acids in conjunction with a statin may be the ideal therapy in these patients.
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- 2012
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25. Substance P concentration in human amniotic membrane.
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Lockington D, Cooney J, Lewis A, Agarwal P, Caslake M, and Ramaesh K
- Subjects
- Humans, Immunoenzyme Techniques, Pilot Projects, Amnion metabolism, Neurotransmitter Agents metabolism, Substance P metabolism
- Published
- 2012
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26. Apolipoprotein E genotype and the cardiovascular disease risk phenotype: impact of sex and adiposity (the FINGEN study).
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Kofler BM, Miles EA, Curtis P, Armah CK, Tricon S, Grew J, Napper FL, Farrell L, Lietz G, Packard CJ, Caslake MJ, Mathers JC, Williams CM, Calder PC, and Minihane AM
- Subjects
- Adult, Age Factors, Biomarkers blood, Body Mass Index, C-Reactive Protein analysis, Cardiovascular Diseases blood, Cardiovascular Diseases physiopathology, Cell Adhesion Molecules blood, Cholesterol blood, Cholesterol, LDL blood, Female, Genetic Predisposition to Disease, Humans, Inflammation Mediators blood, Linear Models, Male, Middle Aged, Phenotype, Prospective Studies, Risk Assessment, Risk Factors, Sex Factors, Triglycerides blood, United Kingdom, Adiposity genetics, Apolipoproteins E genetics, Cardiovascular Diseases genetics
- Abstract
Here the impact of APOE genotype on CHD risk in UK adults is reported, along with an analysis of APOE genotype × BMI/age/sex interactions. APOE genotype had a significant impact on fasting total:LDL-cholesterol (TC:LDL-C) ratio, triglycerides, % HDL3, and the Framingham 10-year CVD risk score (P<0.05), with an overall trend towards lower and higher risk in E2- and E4-carriers, respectively, relative to the wild-type E3/E3 genotype. A greater impact of genotype on TC:HDL-C was observed in females, which explained 16% of the variability in this outcome versus 6% in males. APOE genotype was also associated with plasma C-reactive protein and adhesion molecule concentrations (P<0.05), with significant genotype × BMI interactions observed. Our observations indicate that the association between the APOE genotype and CHD risk is unlikely to be homogenous and highlights the risk of inaccurate estimations of genotype-phenotype associations in population subgroups without appropriate stratification for sex and adiposity., (Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.)
- Published
- 2012
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27. Effects of moderate exercise on VLDL₁ and Intralipid kinetics in overweight/obese middle-aged men.
- Author
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Al-Shayji IA, Caslake MJ, and Gill JM
- Subjects
- Adult, Apolipoproteins B blood, Cholesterol Esters blood, Cross-Over Studies, Emulsions metabolism, Humans, Insulin Resistance, Kinetics, Lipoproteins, VLDL chemistry, Lipoproteins, VLDL metabolism, Male, Middle Aged, Obesity blood, Obesity therapy, Overweight blood, Overweight therapy, Triglycerides blood, Triglycerides metabolism, Walking, Exercise, Fat Emulsions, Intravenous metabolism, Lipid Metabolism, Lipoproteins, VLDL blood, Obesity metabolism, Overweight metabolism, Phospholipids metabolism, Soybean Oil metabolism
- Abstract
Prior moderate exercise reduces plasma triglyceride (TG)-rich lipoprotein concentrations, mainly in the large very low-density lipoprotein (VLDL₁) fraction, but the mechanism responsible is unclear. We investigated the effects of brisk walking on TG-rich lipoprotein kinetics using a novel method. Twelve overweight/obese middle-aged men underwent two kinetic studies, involving infusion of Intralipid to block VLDL₁ catabolism, in random order. On the afternoon prior to infusion, subjects either walked on a treadmill for 2 h at ∼50% maximal oxygen uptake or performed no exercise. Multiple blood samples were taken during and after infusion for separation of Intralipid (S(f) 400) and VLDL₁ (S(f) 60-400). VLDL₁-TG and -apoB production rates were calculated from their linear rises during infusion; fractional catabolic rates (FCR) were calculated by dividing linear rises by fasting concentrations. Intralipid-TG FCR was determined from the postinfusion exponential decay. Exercise reduced fasting VLDL₁-TG concentration by 30% (P = 0.007) and increased TG enrichment of VLDL₁ particles [30% decrease in cholesteryl ester (CE)/TG ratio (P = 0.007); 26% increase in TG/apoB ratio (P = 0.059)]. Exercise also increased VLDL₁-TG, VLDL₁-apoB, and Intralipid-TG FCRs by 82, 146, and 43%, respectively (all P < 0.05), but had no significant effect on VLDL₁-TG or -apoB production rates. The exercise-induced increase in VLDL₁-apoB FCR correlated strongly with the exercise-induced changes in VLDL₁ CE/TG (r = -0.659, r = 0.020) and TG/apoB (r = 0.785, P = 0.002) ratios. Thus, exercise-induced reductions in VLDL₁ concentrations are mediated by increased catabolism, rather than reduced production, which may be facilitated by compositional changes to VLDL₁ particles that increase their affinity for clearance from the circulation.
- Published
- 2012
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28. Apolipoproteins: metabolic role and clinical biochemistry applications.
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Dominiczak MH and Caslake MJ
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- Animals, Apolipoproteins blood, Apolipoproteins genetics, Biomarkers blood, Biomarkers metabolism, Cardiovascular Diseases blood, Cardiovascular Diseases etiology, Cardiovascular Diseases metabolism, Diabetes Mellitus etiology, Diabetes Mellitus genetics, Diabetes Mellitus metabolism, Humans, Insulin Resistance, Lipid Metabolism Disorders complications, Lipid Metabolism Disorders diagnosis, Lipid Metabolism Disorders genetics, Metabolic Syndrome diagnosis, Obesity etiology, Obesity genetics, Obesity metabolism, Postprandial Period, Protein Isoforms blood, Protein Isoforms genetics, Protein Isoforms metabolism, Apolipoproteins metabolism
- Abstract
Lipoprotein metabolism is dependent on apolipoproteins, multifunctional proteins that serve as templates for the assembly of lipoprotein particles, maintain their structure and direct their metabolism through binding to membrane receptors and regulation of enzyme activity. The three principal functions of lipoproteins are contribution to interorgan fuel (triglyceride) distribution (by means of the fuel transport pathway), to the maintenance of the extracellular cholesterol pool (by means of the overflow pathway) and reverse cholesterol transport. The most important clinical application of apolipoprotein measurements in the plasma is in the assessment of cardiovascular risk. Concentrations of apolipoprotein B and apolipoprotein AI (and their ratio) seem to be better markers of cardiovascular risk than conventional markers such as total cholesterol and LDL-cholesterol. Apolipoprotein measurements are also better standardized than the conventional tests. We suggest that measurements of apolipoprotein AI and apolipoprotein B are included as a part of the specialist lipid profile. We also suggest that lipoprotein (a) should be measured as part of the initial assessment of dyslipidaemias because of its consistent association with cardiovascular risk. Genotyping of apolipoprotein E isoforms remains useful in the investigation of mixed dyslipidaemias. Lastly, the role of postprandial metabolism is increasingly recognized in the context of atherogenesis, obesity and diabetes. This requires better markers of chylomicrons, very-low-density lipoproteins and remnant particles. Measurements of apolipoprotein B48 and remnant lipoprotein cholesterol are currently the key tests in this emerging field.
- Published
- 2011
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29. Replication of LDL GWAs hits in PROSPER/PHASE as validation for future (pharmaco)genetic analyses.
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Trompet S, de Craen AJ, Postmus I, Ford I, Sattar N, Caslake M, Stott DJ, Buckley BM, Sacks F, Devlin JJ, Slagboom PE, Westendorp RG, and Jukema JW
- Subjects
- Aged, Humans, Hydroxymethylglutaryl-CoA Reductase Inhibitors therapeutic use, Lipoproteins, LDL blood, Placebos, Polymorphism, Single Nucleotide, Pravastatin therapeutic use, Prospective Studies, Genome-Wide Association Study, Lipoproteins, LDL genetics, Pharmacogenetics
- Abstract
Background: The PHArmacogenetic study of Statins in the Elderly at risk (PHASE) is a genome wide association study in the PROspective Study of Pravastatin in the Elderly at risk for vascular disease (PROSPER) that investigates the genetic variation responsible for the individual variation in drug response to pravastatin. Statins lower LDL-cholesterol in general by 30%, however not in all subjects. Moreover, clinical response is highly variable and adverse effects occur in a minority of patients. In this report we first describe the rationale of the PROSPER/PHASE project and second show that the PROSPER/PHASE study can be used to study pharmacogenetics in the elderly., Methods: The genome wide association study (GWAS) was conducted using the Illumina 660K-Quad beadchips following manufacturer's instructions. After a stringent quality control 557,192 SNPs in 5,244 subjects were available for analysis. To maximize the availability of genetic data and coverage of the genome, imputation up to 2.5 million autosomal CEPH HapMap SNPs was performed with MACH imputation software. The GWAS for LDL-cholesterol is assessed with an additive linear regression model in PROBABEL software, adjusted for age, sex, and country of origin to account for population stratification., Results: Forty-two SNPs reached the GWAS significant threshold of p = 5.0e-08 in 5 genomic loci (APOE/APOC1; LDLR; FADS2/FEN1; HMGCR; PSRC1/CELSR5). The top SNP (rs445925, chromosome 19) with a p-value of p = 2.8e-30 is located within the APOC1 gene and near the APOE gene. The second top SNP (rs6511720, chromosome 19) with a p-value of p = 5.22e-15 is located within the LDLR gene. All 5 genomic loci were previously associated with LDL-cholesterol levels, no novel loci were identified. Replication in WOSCOPS and CARE confirmed our results., Conclusion: With the GWAS in the PROSPER/PHASE study we confirm the previously found genetic associations with LDL-cholesterol levels. With this proof-of-principle study we show that the PROSPER/PHASE study can be used to investigate genetic associations in a similar way to population based studies. The next step of the PROSPER/PHASE study is to identify the genetic variation responsible for the variation in LDL-cholesterol lowering in response to statin treatment in collaboration with other large trials.
- Published
- 2011
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30. Presence of free radicals in intracameral agents commonly used during cataract surgery.
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Lockington D, Macdonald EC, Young D, Stewart P, Caslake M, and Ramaesh K
- Subjects
- Phenylephrine pharmacology, Cataract Extraction, Free Radicals analysis, Ophthalmic Solutions chemistry, Phenylephrine chemistry
- Abstract
Background: Free radicals are known to cause cellular damage and are present in ophthalmic preparations. Corneal defence mechanisms are bypassed in intra-ocular surgery. We evaluated commonly used intracameral agents to ascertain the presence of free radicals and investigate the possibility of anterior segment and endothelial toxicity., Methods: Samples of 19 commonly used intracameral preparations were analysed for total free radical presence on an Instrument Laboratory IL600 using a Randox Kit for Total Antioxidant Status (RANDOX Laboratories Ltd, Crumlin, UK)., Results: Free radical concentrations for the 19 intracameral agents ranged from 0 to 3.59 mmol/l, with median value of 0.34 mmol/l (mean value 0.933±1.19 mmol/l). Phenylephrine had the highest presence of free radicals, which were considerably higher than those for 0.5% hydrogen peroxide at all tested dilutions. Other notable results included cefuroxime (0.61 mmol/l), 2% undiluted lidocaine (0.34 mmol/l) and bevacizumab (0.59 mmol/l)., Conclusion: The results indicate that free radicals are present in intracameral surgical agents and some are in the order of 0.5% hydrogen peroxide. The risks of endothelial damage must be considered when using multiple intracameral preparations in complicated cataract surgery. Free radicals in intracameral preparations may be a contributing cause in cases of toxic anterior segment syndrome.
- Published
- 2010
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31. Intravascular transfer contributes to postprandial increase in numbers of very-low-density hepatitis C virus particles.
- Author
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Felmlee DJ, Sheridan DA, Bridge SH, Nielsen SU, Milne RW, Packard CJ, Caslake MJ, McLauchlan J, Toms GL, Neely RD, and Bassendine MF
- Subjects
- Adult, Disease Progression, Female, Hepacivirus genetics, Hepatitis C, Chronic virology, Humans, Male, Middle Aged, RNA, Viral analysis, Reverse Transcriptase Polymerase Chain Reaction, Viral Load, Viremia virology, Hepacivirus chemistry, Hepatitis C, Chronic blood, Lipoproteins, VLDL analysis, Postprandial Period physiology, Viremia blood, Virion metabolism
- Abstract
Background & Aims: The physical association of hepatitis C virus (HCV) particles with lipoproteins in plasma results in distribution of HCV in a broad range of buoyant densities. This association is thought to increase virion infectivity by mediating cell entry via lipoprotein receptors. We sought to determine if factors that affect triglyceride-rich lipoprotein (TRL) metabolism alter the density and dynamics of HCV particles in the plasma of patients with chronic HCV infection., Methods: Fasting patients (n = 10) consumed a high-fat milkshake; plasma was collected and fractionated by density gradients. HCV- RNA was measured in the very-low-density fraction (VLDF, d < 1.025 g/mL) before and at 7 serial time points postprandially., Results: The amount of HCV RNA in the VLDF (HCV(VLDF)) increased a mean of 26-fold, peaking 180 minutes after the meal (P < .01). Quantification of HCV RNA throughout the density gradient fractions revealed that HCV(VLDF) rapidly disappeared, rather than migrating into the adjacent density fraction. Immuno-affinity separation of the VLDF, using antibodies that recognize apolipoprotein B-100 and not apolipoprotein B-48, showed that HCV(VLDF) is composed of chylomicron- and VLDL-associated HCV particles; peaking 120 and 180 minutes after the meal, respectively. Plasma from fasting HCV-infected patients mixed with uninfected plasma increased the quantity of HCV(VLDF), compared with that mixed with phosphate-buffered saline, showing extracellular assembly of HCV(VLDF)., Conclusions: Dietary triglyceride alters the density and dynamics of HCV in plasma. The rapid clearance rate of HCV(VLDF) indicates that association with TRL is important for HCV infectivity. HCV particles, such as exchangeable apolipoproteins, appear to reassociate with TRLs in the vascular compartment., (Copyright © 2010 AGA Institute. Published by Elsevier Inc. All rights reserved.)
- Published
- 2010
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32. Substrate metabolism, appetite and feeding behaviour under low and high energy turnover conditions in overweight women.
- Author
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Burton FL, Malkova D, Caslake MJ, and Gill JM
- Subjects
- Adult, Cross-Over Studies, Exercise, Exercise Test, Female, Ghrelin blood, Humans, Young Adult, Appetite physiology, Eating, Energy Intake physiology, Energy Metabolism physiology, Overweight metabolism
- Abstract
The present study aimed to investigate whether substrate metabolism, appetite and feeding behaviour differed between high and low energy turnover conditions. Thirteen overweight premenopausal women completed two 1 d trials: low energy turnover (LET) and high energy turnover (HET), in a randomised, cross-over design. In LET, subjects consumed a test breakfast (49% carbohydrate, 37% fat, 14% protein) calculated to maintain energy balance over a 6 h observation period, during which metabolic rate and substrate utilisation were measured and blood samples taken. Immediately following this an ad libitum buffet meal was provided. HET was identical to LET, except that subjects walked on a treadmill for 60 min at 50% VO2max before the test breakfast, which was increased in size (by about 65%) to replace the energy expended during the walk and maintain energy balance over the observation period. Postprandial fat balance (i.e. the difference between fat intake and oxidation) was lower and carbohydrate balance higher in HET compared with LET throughout the postprandial period (P < 0.05 for both). After the buffet meal, carbohydrate balance did not differ between trials but energy and fat balances were lower (by 0.28 MJ and 11.6 g, respectively) in HET compared with LET (P < 0.001 for both). Carbohydrate balance immediately before the buffet meal correlated negatively with buffet energy intake (r -0.49) and postprandial acylated ghrelin responses (r -0.48), and positively with postprandial glucose responses (r 0.49). These findings demonstrate that HET resulted in a more positive carbohydrate balance than LET, which associated with lower subsequent energy intake. This may have implications for the regulation of body weight.
- Published
- 2010
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33. Preliminary post-prandial studies of Burmese cats with elevated triglyceride concentrations and/or presumed lipid aqueous.
- Author
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Kluger EK, Caslake M, Baral RM, Malik R, and Govendir M
- Subjects
- Animals, Area Under Curve, Case-Control Studies, Cats, Fasting blood, Female, Insulin Resistance, Lipid Metabolism, Lipoprotein Lipase metabolism, Lipoproteins blood, Male, Cat Diseases blood, Hyperlipidemias veterinary, Hypertriglyceridemia veterinary, Postprandial Period
- Abstract
A proportion of Burmese cats in Australia have an exaggerated post-prandial triglyceride (TG) response after an oral fat tolerance test (OFTT). The aim of this study was to determine (a) whether Burmese cats with presumed lipid aqueous (PLA) had exaggerated post-prandial triglyceridaemia, (b) if Burmese cats with exaggerated post-prandial triglyceridaemia ('affected' cats) had decreased lipoprotein lipase (LPL) activity and (c) whether affected cats were more insulin resistant than normal Burmese cats. Of cats with a history of PLA, 4/5 were shown to be lipid intolerant (4h TG>4.5mmol/l). Four affected Burmese cats were age, gender and body condition matched to four normal Burmese cats. Serum TG, insulin, non-esterified fatty acids (NEFA), lipoprotein and apolipoprotein concentrations were determined 2 weeks after commencing a standardised high-protein diet, with an OFTT performed 4 weeks later. Affected Burmese cats did not have significantly different fasting insulin, fructosamine, NEFA, apolipoprotein or lipoprotein concentrations compared to control cats. During the OFTT, affected cats had significantly higher 4h and 6h serum TG and NEFA concentrations than normal cats. There was a trend for lower LPL activity, higher insulin concentrations (at 4 and 6h) and higher insulin area under the curve (AUC) during the OFTT in affected Burmese cats compared to controls, although these results failed to reach significance, probably due to the small number of cats studied. Further investigations using larger numbers of cats should focus on reduced LPL activity and insulin resistance as potential causes of delayed TG clearance., (Copyright 2010 ISFM and AAFP. Published by Elsevier Ltd. All rights reserved.)
- Published
- 2010
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34. Lipoprotein-associated phospholipase A(2), inflammatory biomarkers, and risk of cardiovascular disease in the Prospective Study of Pravastatin in the Elderly at Risk (PROSPER).
- Author
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Caslake MJ, Packard CJ, Robertson M, Cooney J, Nelson JJ, Ford I, Gaw A, Jukema JW, Macfarlane PW, Stott DJ, and Shepherd J
- Subjects
- Aged, Aged, 80 and over, C-Reactive Protein analysis, Female, Humans, Inflammation blood, Lipids blood, Lipoproteins blood, Male, Risk Factors, 1-Alkyl-2-acetylglycerophosphocholine Esterase blood, Biomarkers blood, Coronary Disease etiology
- Abstract
Objective: Lipoprotein-associated phospholipase A(2) (Lp-PLA(2)) is an inflammatory biomarker that circulates mainly bound to LDL. We evaluated the association of Lp-PLA(2) with vascular events in the elderly where the importance of LDL is diminished as a risk factor for coronary disease., Methods: Mass and activity of Lp-PLA(2) were related to risk over 3.2 years for vascular events (definite or suspected death from CHD, non-fatal MI, fatal or non-fatal stroke) in the 2804 men and 3000 women age 70-82 years in the Prospective Study of Pravastatin in the Elderly (PROSPER)., Results: Lp-PLA(2) showed a moderate, positive association with risk of a vascular event with hazard ratios of 1.25 (confidence interval (CI) 1.02-1.54) for mass and 1.39 (CI 1.14-1.70) for activity for top versus bottom quartile. Risk associations were attenuated when classical risk factors, lipids and inflammatory markers - C-reactive protein and white cell count - were included in the models. Lp-PLA(2) was unrelated to stroke risk. Inclusion of all three inflammatory markers in multivariate models negated the association of HDL cholesterol with risk (hazard ratio 0.98; CI 0.88-1.10) and increased prediction of coronary events; the C statistic rose from 63.2% to 64.4% (P<0.001)., Conclusion: In elderly people Lp-PLA(2), alongside other inflammatory indices, is a potential biomarker for vascular events, particularly CHD., (Copyright 2009 Elsevier Ireland Ltd. All rights reserved.)
- Published
- 2010
- Full Text
- View/download PDF
35. Presence of free radicals in commonly used ophthalmic preparations.
- Author
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Lockington D, Macdonald E, Gregory M, Stewart P, Caslake M, and Ramaesh K
- Subjects
- Free Radicals analysis, Ophthalmic Solutions chemistry
- Published
- 2010
- Full Text
- View/download PDF
36. Contribution of apolipoprotein E genotype and docosahexaenoic acid to the LDL-cholesterol response to fish oil.
- Author
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Olano-Martin E, Anil E, Caslake MJ, Packard CJ, Bedford D, Stewart G, Peiris D, Williams CM, and Minihane AM
- Subjects
- Adolescent, Adult, Aged, Cell Line, Genotype, Humans, Male, Middle Aged, Young Adult, Apolipoproteins E genetics, Cholesterol, LDL blood, Cholesterol, VLDL blood, Docosahexaenoic Acids administration & dosage, Eicosapentaenoic Acid administration & dosage, Fish Oils administration & dosage
- Abstract
Objectives: To investigate the impact of apolipoprotein E (apoE) genotype on the response of the plasma lipoprotein profile to eicosapentaenoic acid (EPA) versus docosahexaenoic acid (DHA) intervention in humans., Methods and Results: 38 healthy normolipidaemic males, prospectively recruited on the basis of apoE genotype (n=20 E3/E3 and n=18 E3/E4), completed a double-blind placebo-controlled cross-over trial, consisting of 3 x 4 week intervention arms of either control oil, EPA-rich oil (ERO, 3.3g EPA/day) or DHA-rich oil (DRO, 3.7g DHA/day) in random order, separated by 10 week wash-out periods. A significant genotype-independent 28% and 19% reduction in plasma triglycerides in response to ERO and DRO was observed. For total cholesterol (TC), no significant treatment effects were evident; however a significant genotype by treatment interaction emerged (P=0.045), with a differential response to ERO and DRO in E4 carriers. Although the genotype x treatment interaction for LDL-cholesterol (P=0.089) did not reach significance, within DRO treatment analysis indicated a 10% increase in LDL (P=0.029) in E4 carriers with a non-significant 4% reduction in E3/E3 individuals. A genotype-independent increase in LDL mass was observed following DRO intervention (P=0.018). Competitive uptake studies in HepG2 cells using plasma very low density lipoproteins (VLDL) from the human trial, indicated that following DRO treatment, VLDL(2) fractions obtained from E3/E4 individuals resulted in a significant 32% (P=0.002) reduction in LDL uptake relative to the control., Conclusions: High dose DHA supplementation is associated with increases in total cholesterol in E4 carriers, which appears to be due to an increase in LDL-C and may in part negate the cardioprotective action of DHA in this population subgroup.
- Published
- 2010
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37. Lipoprotein-associated phospholipase A2 decreases oxidized lipoprotein cellular association by human macrophages and hepatocytes.
- Author
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Yang M, Chu EM, Caslake MJ, Edelstein C, Scanu AM, and Hill JS
- Subjects
- Cells, Cultured, Flow Cytometry, Humans, Monocytes metabolism, Phospholipases A2 genetics, Phospholipases A2 isolation & purification, Recombinant Proteins genetics, Recombinant Proteins isolation & purification, Recombinant Proteins metabolism, Hepatocytes metabolism, Lipoprotein(a) metabolism, Lipoproteins, LDL metabolism, Macrophages metabolism, Phospholipases A2 metabolism
- Abstract
We investigated whether the presence of endogenous or exogenous lipoprotein-associated phospholipase A2 (Lp-PLA2) can modify the cellular association of oxidized low density lipoprotein (oxLDL) and oxidized lipoprotein(a) (oxLp(a)) by human monocyte-derived macrophages (MDM) and hepatocytes (HepG2). Purified recombinant Lp-PLA2 was used as a source of exogenous enzyme whereas Pefabloc (serine esterase inhibitor) was used to inhibit the endogenous Lp-PLA2 activity associated with isolated lipoproteins. Cellular association studies were performed with DiI-labeled oxLDL or oxLp(a) and human monocyte-derived macrophages and HepG2 cells. Active Lp-PLA2 decreased the cellular association of oxLDL and oxLp(a) in macrophages and HepG2 cells by approximately 30-40%, whereas the inactive enzyme did not significantly change oxidized lipoprotein cellular association by either cell type. OxLDL pretreated by Pefabloc increased oxLDL cellular association by MDM and HepG2 cells compared to untreated oxLDL. Therefore, unlike some lipases, Lp-PLA2 did not appear to have any catalytic independent function in oxLDL cellular association. To assess whether the reduced cellular association mediated by Lp-PLA2 was due to the hydrolysis of oxidized phosphatidylcholine (oxPC), we measured the concentration of lysophosphatidylcholine (lysoPC) in lipoprotein fractions after Lp-PLA2 treatment. LysoPC was increased by 20% (0.4 microM) and 87% (0.7 microM) by active Lp-PLA2 compared to inactive Lp-PLA2 for oxLDL and Lp(a), respectively. LysoPC at higher concentration dose-dependently increased the cellular association of oxLDL and oxLp(a) in MDM and HepG2 cells. We conclude that Lp-PLA2 mediates a decrease in oxidized lipoprotein cellular association in human macrophages and HepG2 cells by reducing the concentration of oxPC within these lipoproteins., (2009 Elsevier B.V. All rights reserved.)
- Published
- 2010
- Full Text
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38. Apolipoprotein e genotype, plasma cholesterol, and cancer: a Mendelian randomization study.
- Author
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Trompet S, Jukema JW, Katan MB, Blauw GJ, Sattar N, Buckley B, Caslake M, Ford I, Shepherd J, Westendorp RG, and de Craen AJ
- Subjects
- Aged, Aged, 80 and over, Apolipoprotein E2 genetics, Apolipoprotein E3 genetics, Apolipoprotein E4 genetics, Confidence Intervals, Female, Genotype, Humans, Linear Models, Male, Neoplasms genetics, Proportional Hazards Models, Prospective Studies, Risk Factors, Apolipoproteins E genetics, Cholesterol blood, Mendelian Randomization Analysis, Neoplasms epidemiology
- Abstract
Observational studies have shown an association between low plasma cholesterol levels and increased risk of cancer, whereas most randomized clinical trials involving cholesterol-lowering medications have not shown this association. Between 1997 and 2002, the authors assessed the association between plasma cholesterol levels and cancer risk, free from confounding and reverse causality, in a Mendelian randomization study using apolipoprotein E (ApoE) genotype. ApoE genotype, plasma cholesterol levels, and cancer incidence and mortality were measured during a 3-year follow-up period among 2,913 participants in the Prospective Study of Pravastatin in the Elderly at Risk. Subjects within the lowest third of plasma cholesterol level at baseline had increased risks of cancer incidence (hazard ratio (HR) = 1.90, 95% confidence interval (CI): 1.34, 2.70) and cancer mortality (HR = 2.03, 95% CI: 1.23, 3.34) relative to subjects within the highest third of plasma cholesterol. However, carriers of the ApoE2 genotype (n = 332), who had 9% lower plasma cholesterol levels than carriers of the ApoE4 genotype (n = 635), did not have increased risk of cancer incidence (HR = 0.86, 95% CI: 0.50, 1.47) or cancer mortality (HR = 0.70, 95% CI: 0.30, 1.60) compared with ApoE4 carriers. These findings suggest that low cholesterol levels are not causally related to increased cancer risk.
- Published
- 2009
- Full Text
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39. Omega-3 fatty acids improve postprandial lipaemia in patients with nephrotic range proteinuria.
- Author
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Bell S, Cooney J, Packard CJ, Caslake M, and Deighan CJ
- Subjects
- Aged, Area Under Curve, Cardiovascular Diseases metabolism, Female, Fish Oils, Humans, Kidney Diseases metabolism, Lipids chemistry, Lipoproteins metabolism, Male, Middle Aged, Postprandial Period, Risk, Fatty Acids, Omega-3 pharmacology, Hyperlipidemias diagnosis, Proteinuria therapy
- Abstract
Background: Patients with nephrotic range proteinuria have a marked increase in the risk of cardiovascular disease. Qualitative and quantitative changes in lipids and lipoproteins contribute to this increased risk with an abundance of atherogenic triglyceride (TG) rich apolipoprotein B containing lipoproteins. TG rich lipoproteins predominate postprandially and are associated with increased risk of coronary heart disease (CHD). Omega-3 fatty acids derived from fish oils have been shown to have beneficial effects on lipids and lipoproteins in patients without proteinuria., Methods: 17 patients with nephrotic range proteinuria and 17 age and sex matched controls were studied. Postprandial lipaemia was assessed in patients and controls, before and after 8 weeks treatment with 4 g daily of omega-3 fatty acids (Omacor). A standard fat load (90 g) was administered and blood sampling was performed in the fasting state and at 2, 4, 6 and 8h after the fat load. Chylomicrons and VLDL(1) density fraction was isolated from plasma by density ultracentrifugation. Postprandial chylomicron and VLDL(1) triglyceride concentrations were measured and quantified using the incremental area under the curve (AUC) method., Results: Baseline postprandial chylomicron TG AUC was greater in patients compared with controls: median 18.5 mmol/lh (interquartile range 8.9-32.6) vs 9.3 mmol/lh (4.8-14.4) p=0.05. Following treatment patient chylomicron AUC fell [mean reduction 6.8 mmol/lh (95% CI 0.1-13.6) p=0.05]. No significant reduction in chylomicron AUC was observed in the controls [mean reduction 3.9 mmol/lh (95% CI -3.6 to 11.5)]. As a result, following 8 weeks treatment with omega-3 fatty acids, patient and control chylomicron AUC were no longer significantly different [patients 13.5 mmol/lh (7.4-22.9), controls 7.2 mmol/lh (4.6-14.5) both median and IQR, p=nsd]. VLDL(1) TG AUC did not differ at baseline between patients and controls. Furthermore, there was no significant effect on VLDL(1) AUC following treatment in either group., Conclusions: We have shown that there is an excess of postprandial chylomicron density fraction in patients with nephrotic range proteinuria, which is reduced by treatment with omega-3 fatty acids. We suggest that this would be an ideal therapy in combination with statins for this high risk group of patients.
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- 2009
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40. Familial hypobetalipoproteinemia due to a novel early stop mutation.
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Durrington PN, Charlton-Menys V, Packard CJ, Caslake MJ, Wang J, Bhatnagar D, Scott J, and Hegele RA
- Abstract
Background: Familial hypobetalipoproteinemia (FHBL) is a co-dominant disorder associated with low circulating levels of low-density lipoprotein (LDL) cholesterol and apolipoprotein B100 (ApoB). A proband was identified in whom the condition was due to an E110X mutation of APOB, creating a particularly early truncation of ApoB in the region of the molecule necessary for very-low-density lipoprotein (VLDL) assembly. The mutation was also associated with nonalcoholic fatty liver disease., Objective: To assess the effect of the mutation on metabolism and the formation of VLDL and LDL subfractions., Results: Both the proband and his son, who had the same mutation, had low LDL cholesterol and decreased ApoB, but an increased small-dense LDL level. Lipoprotein profiles were normal in the proband's sister and grandson, in whom the mutation was absent. In the proband. there was a profoundly diminished rate of production of VLDL-2. VLDL-1 production, however, was relatively preserved and, because of its decreased catabolism, its pool size was increased. Direct formation of intermediate-density lipoprotein (IDL) and LDL was undetectable. Intermediate-density lipoprotein catabolism was greatly increased and its conversion to LDL was increased. The LDL produced was entirely small-dense LDL. High-density lipoprotein cholesterol levels were low, perhaps also related to the relative increase in VLDL-1, which is an avid acceptor of cholesteryl ester., Conclusions: This novel mutation provides evidence to support the hypothesis that hepatic production of large VLDL-1 leads to the creation of small-dense LDL.
- Published
- 2008
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41. Effect of sex and genotype on cardiovascular biomarker response to fish oils: the FINGEN Study.
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Caslake MJ, Miles EA, Kofler BM, Lietz G, Curtis P, Armah CK, Kimber AC, Grew JP, Farrell L, Stannard J, Napper FL, Sala-Vila A, West AL, Mathers JC, Packard C, Williams CM, Calder PC, and Minihane AM
- Subjects
- Adult, Aged, Apolipoproteins blood, Fatty Acids, Nonesterified analysis, Female, Humans, Lipoproteins blood, Male, Middle Aged, United Kingdom, Biomarkers analysis, Diet, Fatty Acids analysis, Fish Oils administration & dosage, Genotype, Oils chemistry, Sex Characteristics
- Abstract
Background: The lipid-modulatory effects of high intakes of the fish-oil fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are well established and likely to contribute to cardioprotective benefits., Objectives: We aimed to determine the effect of moderate EPA and DHA intakes (<2 g EPA+DHA/d) on the plasma fatty acid profile, lipid and apolipoprotein concentrations, lipoprotein subclass distribution, and markers of oxidative status. We also aimed to examine the effect of age, sex, and apolipoprotein E (APOE) genotype on the observed responses., Design: Three hundred twelve adults aged 20-70 y, who were prospectively recruited according to age, sex, and APOE genotype, completed a double-blind placebo-controlled crossover study. Participants consumed control oil, 0.7 g EPA+DHA/d (0.7FO), and 1.8 g EPA+DHA/d (1.8FO) capsules in random order, each for an 8-wk intervention period, separated by 12-wk washout periods., Results: In the group as a whole, 8% and 11% lower plasma triacylglycerol concentrations were evident after 0.7FO and 1.8FO, respectively (P < 0.001): significant sex x treatment (P = 0.038) and sex x genotype x treatment (P = 0.032) interactions were observed, and the greatest triacylglycerol-lowering responses (reductions of 15% and 23% after 0.7FO and 1.8FO, respectively) were evident in APOE4 men. Furthermore, lower VLDL-cholesterol (P = 0.026) and higher LDL-cholesterol (P = 0.010), HDL-cholesterol (P < 0.001), and HDL2 (P < 0.001) concentrations were evident after fish-oil intervention., Conclusions: Supplements providing EPA+DHA at doses as low as 0.7 g/d have a significant effect on the plasma lipid profile. The results of the current trial, which used a prospective recruitment approach to examine the responses in population subgroups, are indicative of a greater triacylglycerol-lowering action of long-chain n-3 polyunsaturated fatty acids in males than in females.
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- 2008
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42. Lipid external quality assessment: commutability between external quality assessment and clinical specimens.
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Cramb R, French J, Mackness M, Neely RD, Caslake M, and MacKenzie F
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- Calibration, Cholesterol analysis, Cholesterol standards, Cholesterol, HDL analysis, Cholesterol, HDL standards, Humans, Lipids standards, Quality Assurance, Health Care, Quality Control, Reference Standards, Reference Values, Reproducibility of Results, Triglycerides analysis, Triglycerides standards, Lipids blood
- Abstract
Background: Targets for cholesterol reduction are part of the Quality Outcomes Framework and general practitioners have to meet these targets to fulfil their remuneration package. By contrast, there are no targets for the accuracy of cholesterol or other lipid measurements and no recent surveys on performance of these assays. We have assessed the performance of lipid measurement of the available methods in the UK., Methods: Serum samples collected from individual donors attending the national blood service were distributed after values were obtained from a secondary reference laboratory. Samples were sent to participant laboratories to assess different methods' analytical performance on single donation specimens, on routine external quality assessment pooled specimens, on specimens subjected to a range of freeze-thaw cycles and on frozen-stored specimens., Results: Differences in measured cholesterol were found that were method-dependent and related to triglyceride content. HDL-cholesterol (HDL-C) showed significant positive bias in all assays. Individual donor specimens showed no significant changes with differing numbers of freeze-thaw cycles. Pooled serum was stable for up to six months., Conclusions: Most cholesterol measurements are accurate but some methods are affected by triglyceride interference. HDL-C methods show significant positive bias. Although there are potential matrix effects introduced as a result of specimen preparation, additional work is needed to show if these effects are present in fresh patient samples.
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- 2008
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43. Identification of potential serum biomarkers of inflammation and lipid modulation that are altered by fish oil supplementation in healthy volunteers.
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de Roos B, Geelen A, Ross K, Rucklidge G, Reid M, Duncan G, Caslake M, Horgan G, and Brouwer IA
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- Aged, Apolipoprotein A-I blood, Apolipoprotein L1, Apolipoproteins blood, Chromatography, Liquid, Dietary Supplements, Double-Blind Method, Electrophoresis, Gel, Two-Dimensional, Enzyme-Linked Immunosorbent Assay, Fish Oils administration & dosage, Haptoglobins analysis, Humans, Lipoproteins, HDL blood, Middle Aged, Seminal Plasma Proteins blood, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization, Tandem Mass Spectrometry, Zn-Alpha-2-Glycoprotein, alpha 1-Antitrypsin blood, Biomarkers blood, Fish Oils pharmacology, Inflammation blood, Lipid Metabolism drug effects
- Abstract
Long chain n-3 polyunsaturated fatty acids (n-3 LCPUFA) lower risk of coronary heart disease (CHD), but mechanisms are not well understood. We used proteomics to identify human serum proteins that are altered by n-3 LCPUFA. Such proteins could identify pathways whereby they affect CHD. Eighty-one healthy volunteers entered a double blind randomised trial to receive 3.5 g of fish oil or 3.5 g of high oleic sunflower oil daily. Serum was collected before and after 6 wk of intervention. Serum was analysed by proteomics using 2-DE. Proteins that were differentially regulated were identified by MS. We also analysed serum apolipoprotein A1 (apo A1), high-density lipoprotein (HDL) particle size and haptoglobin. Serum levels of apo A1, apo L1, zinc-alpha-2-glycoprotein, haptoglobin precursor, alpha-1-antitrypsin precursor, antithrombin III-like protein, serum amyloid P component and haemopexin were significantly downregulated (all p<0.05) by fish oil compared with high oleic sunflower oil supplementation. Fish oil supplementation caused a significant shift towards the larger, more cholesterol-rich HDL(2) particle. The alterations in serum proteins and HDL size imply that fish oil activates anti-inflammatory and lipid modulating mechanisms believed to impede the early onset of CHD. These proteins are potential diagnostic biomarkers to assess the mechanisms whereby fish oil protects against CHD in humans.
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- 2008
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44. Effect of pravastatin on the development of diabetes and adiponectin production.
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Takagi T, Matsuda M, Abe M, Kobayashi H, Fukuhara A, Komuro R, Kihara S, Caslake MJ, McMahon A, Shepherd J, Funahashi T, and Shimomura I
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- Adipocytes drug effects, Animals, Disease Models, Animal, Glucose metabolism, Humans, Male, Mice, Obesity complications, Obesity drug therapy, Adipocytes metabolism, Adiponectin metabolism, Diabetes Mellitus prevention & control, Hydroxymethylglutaryl-CoA Reductase Inhibitors pharmacology, Pravastatin pharmacology
- Abstract
In the West of Scotland Coronary Prevention Study (WOSCOPS), treatment of hypercholesterolemic men with pravastatin, an inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, reduced their likelihood to progress to diabetes mellitus by 30%. However, the mechanism of this effect of pravastatin has not been investigated. In the current study, we examined the effect of pravastatin on the development of diabetes in obese diabetic mice, and on the insulin-induced glucose uptake and adiponectin production. Pravastatin treatment attenuated the development of diabetes in db/db and high fat/high sucrose diet-fed C57BL/6J mice. An in vivo glucose transport assay showed that pravastatin upregulated glucose uptake in adipose tissue. Insulin-stimulated glucose uptake was enhanced in primary adipocytes isolated from pravastatin-treated mice. Pravastatin treatment increased adiponectin production in 3T3-L1 adipocytes. Plasma adiponectin levels were significantly increased in pravastatin-treated mice. Analyses of plasma samples from the WOSCOPS biobank indicated a significant increase of plasma adiponectin levels with pravastatin treatment (placebo -0.28+/-0.34 microg/ml versus pravastatin +1.47+/-0.33 microg/ml, p=0.0003). Taken together, our findings suggest that pravastatin may have beneficial effects on adipose tissue, which may partly explain the reduction of the development of diabetes by pravastatin treatment.
- Published
- 2008
- Full Text
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45. Fractionation of cholesteryl ester rich intermediate density lipoprotein subpopulations by chondroitin sulphate.
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Meyer BJ, Duvillard L, Owen A, Packard CJ, and Caslake MJ
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- Adult, Apolipoproteins blood, Chondroitin Sulfates chemistry, Female, Humans, Lipoproteins analysis, Lipoproteins blood, Male, Ultracentrifugation, Chemical Fractionation methods, Cholesterol Esters chemistry, Chromatography, Agarose methods, Lipoproteins chemistry
- Abstract
IDL is considered an atherogenic lipoprotein but little progress has been made on methods to subfractionate this density class. Furthermore, previous work suggests that lipoproteins retained by the arterial wall, of which chondoitin sulphate is the major arterial wall proteoglycan, are potentially atherogenic. The aim of this study was to assess the subfractionation of IDL particles using chondroitin sulphate (CS). Forty healthy subjects were recruited from laboratory staff and/or their partners. Fasted plasma samples were obtained and IDL (1.006 g/ml
- Published
- 2007
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46. Association between apolipoprotein E4 and cognitive decline in elderly adults.
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Packard CJ, Westendorp RG, Stott DJ, Caslake MJ, Murray HM, Shepherd J, Blauw GJ, Murphy MB, Bollen EL, Buckley BM, Cobbe SM, Ford I, Gaw A, Hyland M, Jukema JW, Kamper AM, Macfarlane PW, Jolles J, Perry IJ, Sweeney BJ, and Twomey C
- Subjects
- Activities of Daily Living classification, Aged, Aged, 80 and over, Alzheimer Disease blood, Alzheimer Disease diagnosis, Anticholesteremic Agents therapeutic use, Cholesterol blood, Cholesterol, HDL blood, Cognition Disorders blood, Cohort Studies, Cross-Sectional Studies, Dementia, Vascular blood, Dementia, Vascular diagnosis, Female, Follow-Up Studies, Genetic Carrier Screening, Homozygote, Humans, Ireland, Male, Mental Status Schedule, Netherlands, Neuropsychological Tests, Pravastatin therapeutic use, Risk Factors, Scotland, Statistics as Topic, Triglycerides blood, Alzheimer Disease genetics, Apolipoprotein E4 genetics, Cholesterol, LDL blood, Cognition Disorders genetics, Dementia, Vascular genetics, Phenotype
- Abstract
Objective: To determine the influence of apolipoprotein E on cognitive decline in a cohort of elderly men and women., Design: Prospective study., Setting: Scotland, Ireland, and the Netherlands., Participants: Five thousand eight hundred four subjects aged 70 to 82 from the Prospective Study of Pravastatin in the Elderly at Risk (PROSPER)., Measurements: Subjects were assessed at baseline and over a mean 3.2-year (range 0.7-4.2) follow-up for memory (Picture-Word Recall), speed of information processing (Stroop and Letter-Digit Coding), global cognitive function (Mini-Mental State Examination), and activities of daily living., Results: At baseline, subjects with apolipoprotein E(4) versus those without E(4) had poorer memory performance (mean score difference -0.20 (95% confidence interval (CI)=-0.31 to -0.09) for immediate recall and -0.32 (95% CI=-0.48 to -0.16) for delayed recall and slower information processing (difference in Stroop, 2.79 seconds, (95% CI=1.20-4.28); Letter-Digit score, -0.36, (95% CI=-0.77-0.05). Subjects with apolipoprotein E(4) showed a greater decline in immediate (-0.22, 95% CI=-0.33 to -0.11) and delayed (-0.30, 95% CI=-0.46 to -0.15) memory scores but no significant change in speed of information processing (Stroop, P=.17; Letter-Digit, P=.06). Memory scores decreased 2.5% from baseline in those without E(4), 4.3% in E(4) heterozygotes (P=.01 for immediate and P=.03 for delayed, vs no E(4)) and 8.9% to 13.8% in E(4) homozygotes (P=.04 for immediate and P=.004 for delayed, vs heterozygotes). Apolipoprotein E(4) was associated with greater decline in instrumental activities of daily living (P<.001). Cognitive decline was not associated with lipoprotein levels., Conclusion: Findings in PROSPER indicate that E(4) is associated with more-rapid cognitive decline and may, therefore, predispose to dementia.
- Published
- 2007
- Full Text
- View/download PDF
47. Effect of prior moderate exercise on postprandial metabolism in men with type 2 diabetes: heterogeneity of responses.
- Author
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Gill JM, Al-Mamari A, Ferrell WR, Cleland SJ, Perry CG, Sattar N, Packard CJ, Caslake MJ, and Petrie JR
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- Adult, Dietary Fats blood, Dietary Fats pharmacokinetics, Exercise Test, Fasting physiology, Fatty Acids, Nonesterified blood, Humans, Ketones metabolism, Male, Middle Aged, Triglycerides blood, Diabetes Mellitus, Type 2 metabolism, Diabetes Mellitus, Type 2 physiopathology, Exercise physiology, Postprandial Period physiology
- Abstract
Unlabelled: Prior moderate exercise has been shown consistently to reduce postprandial triglyceride (TG) concentrations in non-diabetic adults, but its effects in men with type 2 diabetes are not known. This study aimed to determine the effect of moderate exercise on postprandial metabolism in men with type 2 diabetes. Ten middle-aged men with type 2 diabetes underwent two oral fat tolerance tests (blood taken fasting and for 8 h after a meal containing 80 g fat, 70 g carbohydrate) in random order. On the afternoon before one test, participants performed a 90-min treadmill walk (Exercise); no exercise was performed before the CONTROL test. Exercise significantly reduced fasting glucose (, Control: 9.08+/-0.75 mmol l(-1), Exercise: 8.40+/-0.72 mmol l(-1), p=0.033) and insulin (, Control: 8.01+/-0.98 microU ml(-1), Exercise: 6.81+/-0.93 microU ml(-1), p=0.046) and increased fasting 3-hydroxybutyrate (, Control: 87.1+/-19.2 micromol l(-1), Exercise: 134.3+/-28.4 micromol l(-1), p=0.011); reduced postprandial insulin by 11.0% (p=0.04) and increased postprandial 3-hydroxybutyrate by 31.8% (p=0.03); but did not significantly change fasting or postprandial triglyceride or NEFA concentrations. However, the exercise-induced change in postprandial triglyceride concentration ranged from -32.3 to +28.3% and the exercise-induced change in fasting 3-hydroxybutyrate concentration (a marker of hepatic fatty acid oxidation) was highly correlated with the exercise-induced changes in fasting and postprandial triglyceride (r=0.68, p=0.03 for both). Thus, inter-individual variation in propensity to increase hepatic fatty acid oxidation following exercise may account for the considerable heterogeneity in triglyceride responses to moderate exercise observed in men with type 2 diabetes.
- Published
- 2007
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48. Development of a novel method to determine very low density lipoprotein kinetics.
- Author
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Al-Shayji IA, Gill JM, Cooney J, Siddiqui S, and Caslake MJ
- Subjects
- Adult, Apolipoproteins B blood, Chylomicrons metabolism, Fat Emulsions, Intravenous administration & dosage, Female, Humans, Kinetics, Male, Middle Aged, Triglycerides blood, Lipoproteins, VLDL blood
- Abstract
Isotopic tracer methods of determining triglyceride-rich lipoprotein (TRL) kinetics are costly, time-consuming, and labor-intensive. This study aimed to develop a simpler and cost-effective method of obtaining TRL kinetic data, based on the fact that chylomicrons compete with large VLDL (VLDL(1); S(f) = 60-400) for the same catalytic pathway. Ten healthy subjects [seven men; fasting triglyceride (TG), 44.3-407.6 mg/dl; body mass index, 21-35 kg/m(2)] were given an intravenous infusion of a chylomicron-like TG emulsion (Intralipid; 0.1 g/kg bolus followed by 0.1 g/kg/h infusion) for 75-120 min to prevent the clearance of VLDL(1) by lipoprotein lipase. Multiple blood samples were taken during and after infusion for separation of Intralipid, VLDL(1), and VLDL(2) by ultracentrifugation. VLDL(1)-apolipoprotein B (apoB) and TG production rates were calculated from their linear increases in the VLDL(1) fraction during the infusion. Intralipid-TG clearance rate was determined from its exponential decay after infusion. The production rates of VLDL(1)-apoB and VLDL(1)-TG were (mean +/- SEM) 25.4 +/- 3.9 and 1,076.7 +/- 224.7 mg/h, respectively, and the Intralipid-TG clearance rate was 66.9 +/- 11.7 pools/day. Kinetic data obtained from this method agree with values obtained from stable isotope methods and show the expected relationships with indices of body fatness and insulin resistance (all P < 0.05). The protocol is relatively quick, inexpensive, and transferable to nonspecialist laboratories.
- Published
- 2007
- Full Text
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49. Benefits of salmon eating on traditional and novel vascular risk factors in young, non-obese healthy subjects.
- Author
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Lara JJ, Economou M, Wallace AM, Rumley A, Lowe G, Slater C, Caslake M, Sattar N, and Lean ME
- Subjects
- Adult, Animals, Blood Pressure, Cholesterol, HDL blood, Cholesterol, LDL blood, Coronary Disease blood, Coronary Disease etiology, Coronary Disease physiopathology, Dietary Fats, Unsaturated administration & dosage, Female, Fish Oils administration & dosage, Humans, Lipids blood, Male, Middle Aged, Risk Factors, Triglycerides blood, Coronary Disease prevention & control, Diet, Salmon
- Abstract
Aim: The present clinical study tested the hypothesis that oil-rich fish consumption improves CHD risk factors., Methods: Forty-eight (16 men) non-obese, healthy adults aged 20-55, consumed 125 g/day of salmon for a 4-week period followed by a 4-week period with no-fish (41 completers). Subjects were instructed to maintain dietary and physical activity patterns during the period of study. Blood pressure, anthropometric, body composition and dietary information with fasting blood samples to determine traditional and novel CHD risk markers and plasma fatty acids were obtained before and after each period., Results: Compared to no-fish, eating salmon significantly decreased systolic, diastolic and mean arterial blood pressure by 4%, triglycerides by 15%, and LDL-cholesterol by 7%, and significantly increased HDL-cholesterol by 5% (P<0.05). The changes in blood pressure and lipids alone with salmon intake predict around a 25% reduction in CHD risk based on the PROCAM risk calculator. Plasma adiponectin demonstrated a trend towards improvement (8.39 micromol/L with salmon and 7.52 with no-fish; P=0.086) but no significant changes were found either in plasma leptin, glucose or insulin after salmon consumption., Conclusions: Daily consumption of salmon improves traditional risk predictors of CHD in non-obese subjects. Adiponectin may be involved but the impact on novel risk factors needs study in high-risk subjects.
- Published
- 2007
- Full Text
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50. Effects of soluble fiber (Plantago ovata husk) on plasma lipids, lipoproteins, and apolipoproteins in men with ischemic heart disease.
- Author
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Solà R, Godàs G, Ribalta J, Vallvé JC, Girona J, Anguera A, Ostos M, Recalde D, Salazar J, Caslake M, Martín-Luján F, Salas-Salvadó J, and Masana L
- Subjects
- Angina Pectoris blood, Angina Pectoris diet therapy, Angina Pectoris genetics, Cross-Over Studies, Dietary Fiber administration & dosage, Genotype, Humans, Male, Middle Aged, Myocardial Infarction blood, Myocardial Infarction diet therapy, Myocardial Infarction genetics, Myocardial Ischemia genetics, Patient Compliance, Plantago, Single-Blind Method, Solubility, Apolipoproteins blood, Dietary Fiber pharmacology, Lipids blood, Lipoproteins blood, Myocardial Ischemia blood, Myocardial Ischemia diet therapy
- Abstract
Background: New dietary strategies to reduce cardiovascular disease (CVD) risk include the addition of fiber to the diet. The effect of soluble-fiber consumption derived from Plantago ovata husk on lipid risk factors in patients with CVD is unknown., Objective: We compared the effects of soluble fiber (P. ovata husk) with those of insoluble fiber (P. ovata seeds) on plasma lipid, lipoprotein, and apolipoprotein (apo) concentrations within a CVD secondary prevention program., Design: In a randomized, crossover, controlled, single-blind design, 28 men with CVD (myocardial infarction or stable angina) and an LDL-cholesterol concentration =3.35 mmol/L consumed for 8 wk, under controlled conditions, a low-saturated-fat diet supplemented with 10.5 g P. ovata husk/d or 10.5 g P. ovata seeds/d. Fasting plasma lipid concentrations and polymorphisms of genes involved in lipid metabolism, such as apo A-IV, apo E, and fatty acid-binding protein, were measured., Results: Plasma triacylglycerol decreased (6.7%; P < 0.02), the ratio of apo B 100 to apo A-I decreased (4.7%; P < 0.02), and apo A-I increased (4.3%; P < 0.01) in the P. ovata husk consumers. Compared with the intake of insoluble fiber, the intake of P. ovata husk increased HDL-cholesterol concentrations by 6.7% (P = 0.006) and decreased the ratio of total to HDL cholesterol and of LDL to HDL cholesterol by 10.6% (P = 0.002) and 14.2% (P = 0.003), respectively., Conclusion: In the secondary prevention of CVD, P. ovata husk intake induces a more beneficial effect on the cardiovascular lipid risk-factor profile than does an equivalent intake of insoluble fiber.
- Published
- 2007
- Full Text
- View/download PDF
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