Search

Cardiovascular disease (CVD) is a major cause of death in Western societies. CVD risk is largely genetically determined. The molecular pathology is, however, not elucidated in a large number of families suffering from CVD. We applied exclusion linkage analysis and next-generation sequencing to elucidate the molecular defect underlying premature CVD in a small pedigree, comprising two generations of which six members suffered from premature CVD. A total of three variants showed co-segregation with the disease status in the family. Two of these variants were excluded from further analysis based on the prevalence in replication cohorts, whereas a non-synonymous variant in MCF.2 Cell Line Derived Transforming Sequence-like protein (MCF2L, c.2066A>G; p.(Asp689Gly); NM_001112732.1), located in the DH domain, was only present in the studied family. MCF2L is a guanine exchange factor that potentially links pathways that signal through Rac1 and RhoA. Indeed, in HeLa cells, MCF2L689Gly failed to activate Rac1 as well as RhoA, resulting in impaired stress fiber formation. Moreover, MCF2L protein was found in human atherosclerotic lesions but not in healthy tissue segments. In conclusion, a rare functional variant in MCF2L, leading to impaired DH function, was identified in a small pedigree with premature CVD. The presence of MCF2L in human atherosclerotic plaque specimen lends further support to its potential role in atherosclerosis.

Blood pressure (BP) is a heritable risk factor for cardiovascular disease. To investigate genetic associations with systolic BP (SBP), diastolic BP (DBP), mean arterial pressure (MAP), and pulse pressure (PP), we genotyped ∼50,000 SNPs in up to 87,736 individuals of European ancestry and combined these in a meta-analysis. We replicated findings in an independent set of 68,368 individuals of European ancestry. Our analyses identified 11 previously undescribed associations in independent loci containing 31 genes including PDE1A, HLA-DQB1, CDK6, PRKAG2, VCL, H19, NUCB2, RELA, HOXC@ complex, FBN1, and NFAT5 at the Bonferroni-corrected array-wide significance threshold (p < 6 × 10-7) and confirmed 27 previously reported associations. Bioinformatic analysis of the 11 loci provided support for a putative role in hypertension of several genes, such as CDK6 and NUCB2. Analysis of potential pharmacological targets in databases of small molecules showed that ten of the genes are predicted to be a target for small molecules. In summary, we identified previously unknown loci associated with BP. Our findings extend our understanding of genes involved in BP regulation, which may provide new targets for therapeutic intervention or drug response stratification. © 2014 The American Society of Human Genetics.

To access publisher's full text version of this article click on the hyperlink at the bottom of the page To further understanding of the genetic basis of type 2 diabetes (T2D) susceptibility, we aggregated published meta-analyses of genome-wide association studies (GWAS), including 26,488 cases and 83,964 controls of European, east Asian, south Asian and Mexican and Mexican American ancestry. We observed a significant excess in the directional consistency of T2D risk alleles across ancestry groups, even at SNPs demonstrating only weak evidence of association. By following up the strongest signals of association from the trans-ethnic meta-analysis in an additional 21,491 cases and 55,647 controls of European ancestry, we identified seven new T2D susceptibility loci. Furthermore, we observed considerable improvements in the fine-mapping resolution of common variant association signals at several T2D susceptibility loci. These observations highlight the benefits of trans-ethnic GWAS for the discovery and characterization of complex trait loci and emphasize an exciting opportunity to extend insight into the genetic architecture and pathogenesis of human diseases across populations of diverse ancestry. Canadian Institutes of Health Research Medical Research Council UK G0601261 Mexico Convocatoria SSA/IMMS/ISSSTE-CONACYT 2012-2 clave 150352 IMSS R-2011-785-018 CONACYT Salud-2007-C01-71068 US National Institutes of Health DK062370 HG000376 DK085584 DK085545 DK073541 DK085501 Wellcome Trust WT098017 WT090532 WT090367 WT098381 WT081682 WT085475 info:eu-repo/grantAgreement/EC/FP7/201413

In recent years, multiple loci dispersed on the genome have been shown to be associated with coronary artery disease (CAD). We investigated whether these common genetic variants also hold value for CAD prediction in a large cohort of patients with familial hypercholesterolemia (FH). We genotyped a total of 41 single-nucleotide polymorphisms (SNPs) in 1701 FH patients, of whom 482 patients (28.3%) had at least one coronary event during an average follow up of 66 years. The association of each SNP with event-free survival time was calculated with a Cox proportional hazard model. In the cardiovascular disease risk factor adjusted analysis, the most significant SNP was rs1122608:G>T in the SMARCA4 gene near the LDL-receptor (LDLR) gene, with a hazard ratio for CAD risk of 0.74 (95% CI 0.49–0.99; P-value 0.021). However, none of the SNPs reached the Bonferroni threshold. Of all the known CAD loci analyzed, the SMARCA4 locus near the LDLR had the strongest negative association with CAD in this high-risk FH cohort. The effect is contrary to what was expected. None of the other loci showed association with CAD.

Blood pressure (BP) is a heritable determinant of risk for cardiovascular disease (CVD). To investigate genetic associations with systolic BP (SBP), diastolic BP (DBP), mean arterial pressure (MAP) and pulse pressure (PP), we genotyped ∼50 000 single-nucleotide polymorphisms (SNPs) that capture variation in ∼2100 candidate genes for cardiovascular phenotypes in 61 619 individuals of European ancestry from cohort studies in the USA and Europe. We identified novel associations between rs347591 and SBP (chromosome 3p25.3, in an intron of HRH1) and between rs2169137 and DBP (chromosome1q32.1 in an intron of MDM4) and between rs2014408 and SBP (chromosome 11p15 in an intron of SOX6), previously reported to be associated with MAP. We also confirmed 10 previously known loci associated with SBP, DBP, MAP or PP (ADRB1, ATP2B1, SH2B3/ATXN2, CSK, CYP17A1, FURIN, HFE, LSP1, MTHFR, SOX6) at array-wide significance (P < 2.4 × 10(-6)). We then replicated these associations in an independent set of 65 886 individuals of European ancestry. The findings from expression QTL (eQTL) analysis showed associations of SNPs in the MDM4 region with MDM4 expression. We did not find any evidence of association of the two novel SNPs in MDM4 and HRH1 with sequelae of high BP including coronary artery disease (CAD), left ventricular hypertrophy (LVH) or stroke. In summary, we identified two novel loci associated with BP and confirmed multiple previously reported associations. Our findings extend our understanding of genes involved in BP regulation, some of which may eventually provide new targets for therapeutic intervention.

Study Hypothesis Recently, genome-wide association studies (GWAS) have identified several common variants associated with increased risk of coronary artery disease (CAD) and myocardial infarction (MI) by 10% to 30%. The authors state that these loci explain only a small proportion of the predicted genetic risk and that all of the current loci for CAD and MI by GWAS have been discovered in European populations. The authors hypothesized that discovery of new susceptibility loci of smaller effect sizes would be aided by conducting much larger studies in addition to an emphasis on early-onset CAD and clearly defined clinical end points. Therefore, they assembled the Coronary Artery Disease (C4D) Genetics Consortium.1 ### How Was the Hypothesis Tested? The authors performed a meta-analysis of 4 large GWAS of CAD, 2 of European ancestry (PROCARDIS and HPS) and 2 of South Asian ancestry (PROMIS and LOLLIPOP), with ≈575 000 genotyped single-nucleotide polymorphisms (SNPs) in a discovery data set comprising 15 420 individuals with CAD (cases) (8424 Europeans and 6996 South Asians) and 15 062 control subjects. They observed little evidence for ancestry-specific associations, supporting the use of combined analyses. Furthermore, the authors state that because all individuals were genotyped on the same platform (whole-genome Illumina BeadChips), a meta-analysis of actual genotypes rather than imputed data enabled analysis of low-frequency variants (1% to 5%), which have been excluded from GWAS either because of sample size or because imputation has been required to combine data from different genotyping platforms. After the meta-analysis, they selected 59 SNPs from 50 loci that showed potential new associations from the meta-analysis of the European and South Asian studies (41 SNPs; P

Genome-wide association studies (GWASs) have identified many SNPs underlying variations in plasma-lipid levels. We explore whether additional loci associated with plasma-lipid phenotypes, such as high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), total cholesterol (TC), and triglycerides (TGs), can be identified by a dense gene-centric approach. Our meta-analysis of 32 studies in 66,240 individuals of European ancestry was based on the custom ∼50,000 SNP genotyping array (the ITMAT-Broad-CARe array) covering ∼2,000 candidate genes. SNP-lipid associations were replicated either in a cohort comprising an additional 24,736 samples or within the Global Lipid Genetic Consortium. We identified four, six, ten, and four unreported SNPs in established lipid genes for HDL-C, LDL-C, TC, and TGs, respectively. We also identified several lipid-related SNPs in previously unreported genes: DGAT2, HCAR2, GPIHBP1, PPARG, and FTO for HDL-C; SOCS3, APOH, SPTY2D1, BRCA2, and VLDLR for LDL-C; SOCS3, UGT1A1, BRCA2, UBE3B, FCGR2A, CHUK, and INSIG2 for TC; and SERPINF2, C4B, GCK, GATA4, INSR, and LPAL2 for TGs. The proportion of explained phenotypic variance in the subset of studies providing individual-level data was 9.9% for HDL-C, 9.5% for LDL-C, 10.3% for TC, and 8.0% for TGs. This large meta-analysis of lipid phenotypes with the use of a dense gene-centric approach identified multiple SNPs not previously described in established lipid genes and several previously unknown loci. The explained phenotypic variance from this approach was comparable to that from a meta-analysis of GWAS data, suggesting that a focused genotyping approach can further increase the understanding of heritability of plasma lipids. © 2012 The American Society of Human Genetics.

Aims A randomized, double-blind, placebo-controlled study was conducted to investigate the safety and efficacy of mipomersen, an apolipoprotein B-100 (apoB) synthesis inhibitor, in patients who are statin intolerant and at high risk for cardiovascular disease (CVD). Methods and results Thirty-three subjects, not receiving statin therapy because of statin intolerance, received a weekly subcutaneous dose of 200 mg mipomersen or placebo (2:1 randomization) for 26 weeks. The primary endpoint was per cent change in LDL cholesterol (LDL-c) from the baseline to Week 28. The other efficacy endpoints were per cent change in apoB and lipoprotein a [Lp(a)]. Safety was determined using the incidence of treatment-emergent adverse events (AEs) and clinical laboratory evaluations. After 26 weeks of mipomersen administration, LDL-c was reduced by 47 ± 18% ( P < 0.001 vs. placebo). apoB and Lp(a) were also significantly reduced by 46 and 27%, respectively ( P < 0.001 vs. placebo). Four mipomersen (19%) and two placebo subjects (17%) discontinued dosing prematurely due to AEs. Persistent liver transaminase increases ≥3× the upper limit of normal were observed in seven (33%) subjects assigned to mipomersen. In selected subjects, liver fat content was assessed, during and after treatment, using magnetic resonance spectroscopy. Liver fat content in these patients ranged from 0.8 to 47.3%. Liver needle biopsy was performed in two of these subjects, confirming hepatic steatosis with minimal inflammation or fibrosis. Conclusion The present data suggest that mipomersen is a potential therapeutic option in statin-intolerant patients at high risk for CVD. The long-term follow-up of liver safety is required. Clinical Trial Registration: ClinicalTrials.gov identifier: [NCT00707746][1] [1]: /lookup/external-ref?link_type=CLINTRIALGOV&access_num=NCT00707746&atom=%2Fehj%2Fearly%2F2012%2F04%2F16%2Feurheartj.ehs023.atom

Summary Background Persistent inflammation has been proposed to contribute to various stages in the pathogenesis of cardiovascular disease. Interleukin-6 receptor (IL6R) signalling propagates downstream inflammation cascades. To assess whether this pathway is causally relevant to coronary heart disease, we studied a functional genetic variant known to affect IL6R signalling. Methods In a collaborative meta-analysis, we studied Asp358Ala (rs2228145) in IL6R in relation to a panel of conventional risk factors and inflammation biomarkers in 125 222 participants. We also compared the frequency of Asp358Ala in 51 441 patients with coronary heart disease and in 136 226 controls. To gain insight into possible mechanisms, we assessed Asp358Ala in relation to localised gene expression and to postlipopolysaccharide stimulation of interleukin 6. Findings The minor allele frequency of Asp358Ala was 39%. Asp358Ala was not associated with lipid concentrations, blood pressure, adiposity, dysglycaemia, or smoking (p value for association per minor allele ≥0·04 for each). By contrast, for every copy of 358Ala inherited, mean concentration of IL6R increased by 34·3% (95% CI 30·4–38·2) and of interleukin 6 by 14·6% (10·7–18·4), and mean concentration of C-reactive protein was reduced by 7·5% (5·9–9·1) and of fibrinogen by 1·0% (0·7–1·3). For every copy of 358Ala inherited, risk of coronary heart disease was reduced by 3·4% (1·8–5·0). Asp358Ala was not related to IL6R mRNA levels or interleukin-6 production in monocytes. Interpretation Large-scale human genetic and biomarker data are consistent with a causal association between IL6R-related pathways and coronary heart disease. Funding British Heart Foundation; UK Medical Research Council; UK National Institute of Health Research, Cambridge Biomedical Research Centre; BUPA Foundation.

Cardiovascular disease remains the major cause of worldwide morbidity and mortality. Its pathophysiology is complex and multifactorial. Because the phenotype of cardiovascular disease often shows a marked heritable pattern, it is likely that genetic factors play an important role. In recent years, large genome-wide association studies have been conducted to decipher the molecular mechanisms underlying this heritable and prevalent phenotype. The emphasis of this review is on the recently identified 17 susceptibility loci for coronary artery disease. Implications of their discovery for biology and clinical medicine are discussed. A description of the landscape of human genetics in the near future in the context of next-generation sequence technologies is provided at the conclusion of this review.

Background: MPO, an enzyme of the innate immune system, exhibits pro-atherogenic effects. These include oxidative damage to LDL- and HDL-cholesterol, and promotion of endothelial dysfunction. Recent studies revealed that MPO independently predicts adverse outcomes in patients with chest pain or suspected acute coronary syndrome. We evaluated whether plasma myeloperoxidase (MPO) levels are associated with scintigraphic myocardial perfusion abnormalities, in type 2 diabetic patients with mild anginal complaints. Methods: MPO was measured in plasma samples of 267 patients with diabetes mellitus type 2 and stable angina pectoris complaints (Canadian Cardiovascular Society class I-II/IV) prior to myocardial perfusion scintigraphy (MPS). Results: The median plasma level of MPO was 141 pmol/L (IQR 115-171 pmol/L). One-hundred-ninety patients (71%) had perfusion abnormalities on MPS and of these, 138 patients had myocardial ischemia. No relation was found between plasma MPO levels and the scintigraphic myocardial perfusion abnormalities. Even in combination with known other cardiovascular risk factors MPO failed to predict scintigraphic myocardial perfusion abnormalities. Conclusions: MPO levels are not associated with scintigraphic myocardial perfusion abnormalities in type 2 diabetic patients with mild anginal complaints. Therefore, in type 2 diabetic patients MPO is not a useful biomarker to predict hemodynamically significant coronary artery disease. (C) 2010 Elsevier B.V. All rights reserved

Background— Genetic cascade screening for heterozygous familial hypercholesterolemia (FH) revealed that 15% of individuals given this diagnosis do not exhibit elevated low-density lipoprotein cholesterol (LDL-C) levels. We assessed whether cardiovascular risk for these individuals differs from that of hypercholesterolemic FH heterozygotes and unaffected relatives. Methods and Results— Individuals aged 18 to 55 years were recruited within 18 months after genetic screening. Three groups were studied: subjects given a molecular diagnosis of FH and with LDL-C levels at genetic screening below the 75th percentile (FH-low), subjects with FH and an LDL-C level above the 90th percentile (FH-high), and subjects without FH (no-FH). We measured carotid intima-media thickness (IMT) by ultrasonography. Differences in carotid IMT among the groups were assessed using multivariate linear regression analyses. Mean carotid IMT of 114 subjects in the FH-low group (0.623 mm; 95% CI, 0.609 to 0.638 mm) was significantly smaller than that of 162 subjects in the FH-high group (0.664 mm; 95% CI, 0.648 to 0.679 mm; P P =0.67). Conclusions— Our findings suggest that the risk of cardiovascular disease in patients with FH to a large extent is related to LDL-C levels and not to the presence of a mutation per se. Consequently, this study cautiously suggests that individuals with an FH genotype without expression of hypercholesterolemia may not require a pharmaceutical intervention that is as aggressive as the standard for subjects with FH.

Objectives The aim of this study was to evaluate the efficacy and safety of mipomersen in hypercholesterolemic subjects taking stable statin therapy. Background Mipomersen is an apolipoprotein (apo) B synthesis inhibitor that has demonstrated significant reductions in apo B and low-density lipoprotein (LDL) cholesterol in Phase 1 clinical trials in healthy volunteers. Methods A randomized, placebo-controlled, dose-escalation Phase 2 study was designed to evaluate the effects of mipomersen in hypercholesterolemic subjects taking stable statin therapy. Seventy-four subjects were enrolled sequentially into 1 of 6 dose cohorts at a 4:1 (active/placebo) ratio. Subjects received 7 doses of 30 to 400 mg over 5 weeks in the first 5 cohorts and 15 doses of 200 mg over 13 weeks in the sixth cohort. Pre-specified end points included percentage change from baseline in apo B and LDL cholesterol. Safety was assessed with laboratory test results and by the incidence and severity of adverse events. Results The apo B and LDL cholesterol were reduced by 19% to 54% and 21% to 52%, respectively, at doses of 100 mg/week mipomersen and higher in the 5-week treatment cohorts. Efficacy seemed to increase upon treatment for 13 weeks at a dose of 200 mg/week. Injection site reactions (mild to moderate erythema [90%]) and hepatic transaminase increases (17%) were the most common adverse events, leading to discontinuation in 2 subjects and 1 subject, respectively. In the 13-week treatment cohort, 5 of 10 subjects (50%) had elevations >= 3x the upper limit of normal, 4 of which persisted on 2 consecutive occasions. Conclusions Mipomersen might hold promise for treatment of patients not reaching target LDL cholesterol levels on stable statin therapy. Further studies are needed to address the mechanisms and clinical relevance of transaminase changes after mipomersen administration. (Dose-Escalating Safety Study in Subjects on Stable Statin Therapy; NCT00231569) (J Am Coll Cardiol 2010;55:1611-8) (C) 2010 by the American College of Cardiology Foundation

Contains fulltext : 89207.pdf (Publisher’s version ) (Closed access) BACKGROUND: Familial hypercholesterolemia (FH) has been associated with increased cardiovascular risk when untreated or when normal LDL-C concentrations are not reached. Some patients with FH do not reach LDL-C goals despite intensive combination therapy. OBJECTIVE: This study assessed the efficacy and tolerability of colesevelam added to maximally tolerated, stable-dose combination treatment with a statin + ezetimibe. METHODS: This Phase IV, multicenter, randomized, double-blind, placebo-controlled trial enrolled patients aged 18 to 75 years with FH and an LDL-C concentration >2.5 mmol/L who were receiving a maximally tolerated and stable regimen of a statin + ezetimibe. Patients were randomly assigned to receive colesevelam 3.75 g/d or placebo added to the statin + ezetimibe for 12 weeks. The primary efficacy outcome was the difference in LDL-C between the colesevelam and placebo groups after 6 weeks. Secondary efficacy outcomes were between-group differences in LDL-C, total cholesterol (TC), HDL-C, triglyceride (Tg), apolipoprotein (apo) B, and apoA-I concentrations, as well as apoB/apoA-I ratio after 12 weeks. Tolerability was assessed based on the prevalences of adverse events by organ system class in each treatment group. RESULTS: Eighty-six patients were randomized (45 colesevelam, 41 placebo), of whom 84 (44 colesevelam, 40 placebo) were included in the primary analysis. The mean (SD) age of the participants was 52.8 (10.8) years, and 51 (59%) were men. The difference (95% CI) in LDL-C between colesevelam and placebo after 6 weeks was -18.5% (-25.3 to -11.8). Between-group differences in LDL-C, TC, HDL-C, Tg, and apoB/apoA-I ratio after 12 weeks were -12.0% (-17.8 to -6.3), -7.3% (-12.0 to -2.6), +3.3% (-2.4 to +9.0), +2.8% (-10.4 to +15.9), and -12.2% (-20.2 to -4.2), respectively. Colesevelam was generally well tolerated, with gastrointestinal adverse events in 12 of 45 patients (27%) versus 7 of 40 (18%) in the placebo group (P = NS). CONCLUSION: In these patients with FH, colesevelam added to a combination of a statin + ezetimibe was associated with significantly improved LDL-C concentrations compared with placebo during the 12-week study period and was generally well tolerated. 01 april 2010

Aim: To determine the prognostic value of reversible myocardial perfusion defects on myocardial perfusion scintigraphy (MPS) in patients with type 2 diabetes mellitus and mild anginal complaints.Methods and results: In the MERIDIAN trial, patients with diabetes mellitus type 2, stable, mild anginal symptoms (Canadian Cardiovascular Society classification (CCS) I-II/IV) and reversible perfusion defects were randomized to either continued pharmacological treatment or early invasive treatment. In this sub analysis, the severity of the myocardial perfusion defect was related to the occurrence of cardiac death and non-fatal myocardial infarction, in 319 patients (63% male, 65 ± 9 years). During follow-up (2.2 ± 0.6 years), 14 patients had a cardiac event: 3 in 171 patients without myocardial ischemia and 11 in 148 patients with myocardial ischemia. Annual event rates rose from 0.8% to 5.8% with increasing severity of myocardial ischemia. Multivariable analysis identified the presence of severe myocardial ischemia (hazard ratio (HR) 5.45, 95%CI 1.89-15.71) and insulin use (HR 4.00, 95%CI 1.25-12.75) as independent predictors of cardiac events.Conclusions: Type 2 diabetics with mild anginal symptoms with no or moderate myocardial ischemia have a low annual cardiac event rate. In patients with severe myocardial ischemia event rate increased 3-6 fold.

Objective This study investigated the efficacy, safety, tolerability, and pharmacokinetics of a novel cholesterol absorption inhibitor, FM-VP4, comprising disodium ascorbyl sitostanol phosphate (DASP) and disodium ascorbyl campestanol phosphate (DACP).Methods In phase 1, 30 men received a single dose of 100, 200, 400, 800, 1,600, or 2,000 mg FM-VP4 or placebo. In phase 2, 100 men were treated with 100, 200, 400, or 800 mg/day of FM-VP4 or placebo for 4 weeks.Results The drug was well tolerated at each single or multiple dose level. After 4 weeks of treatment, low-density lipoprotein cholesterol (LDL-C) levels changed by 2.7% in the placebo group and by 2.9%, -4.2%, and -4.6% in the 100, 200, and 800 mg/day groups, respectively, which was not statistically significant. However, 400 mg/day of FM-VP4 significantly decreased LDL-C by 6.5% (p=0.02). Phase 1 showed that DACP and DASP were absorbed into plasma with a median t(max) of 12 h for both components, and clearance was slow with a mean t(1/2 lambda) of 57 h. During 4 weeks of treatment, steady state was reached by approximately 8 days.Conclusion This study demonstrated that up to 800 mg/day of FM-VP4 is safe and well tolerated for at least 4 weeks. Furthermore, the higher doses significantly reduced LDL-C by 7% compared with baseline or by 10% compared with placebo, with the maximum effect reached at 400 mg/day.

OBJECTIVE: To determine lipoprotein particle concentrations and size in children with familial hypercholesterolemia (FH) and investigate the effect of pravastatin therapy on these measures. STUDY DESIGN: Lipoprotein particle concentrations and sizes were examined by nuclear magnetic resonance (NMR) spectroscopy in 144 children with FH and 45 unaffected siblings. The effect of pravastatin therapy (20 to 40 mg) on lipoprotein particle concentration and size were compared with placebo after 1 year of treatment, using analysis of covariance. RESULTS: Compared with the unaffected siblings, the children with FH had significantly higher concentrations of very-low-density lipoprotein (VLDL) particles (115.6 nmol/L vs 51.2 nmol/L; P < .001) and low-density lipoprotein (LDL) particles (1726.8 nmol/L vs 955.3 nmol/L; P < .001), and lower concentrations of high-density lipoprotein (HDL) particles (23.2 micromol/L vs 26.9 micromol/L; P < .001). Compared with placebo, pravastatin therapy decreased the concentration of VLDL particles by 35.9 nmol/L (P < .001), of total LDL particles by 342.7 nmol/L (P < .001), of large LDL particles by 189.5 nmol/L (P < .001), and of small LDL particles by 156.2 nmol/L (P = .152), but increased the concentration of total HDL particles by 2.2 micromol/L (P < .001), of large HDL particles by 1.0 micromol/L (P = .006), and of medium HDL particles by 1.1 micromol/L (P = .003). VLDL particle size increased by 1.0 nm (P = .032). CONCLUSIONS: Compared with their healthy siblings, children with FH have an atherogenic lipoprotein profile based on their lipoprotein distribution and lipoprotein particle diameter. Pravastatin therapy can improve, but not fully restore, these lipoprotein abnormalities toward normal levels in these children

Contains fulltext : 71032.pdf ( ) (Closed access) BACKGROUND: Ezetimibe, a cholesterol-absorption inhibitor, reduces levels of low-density lipoprotein (LDL) cholesterol when added to statin treatment. However, the effect of ezetimibe on the progression of atherosclerosis remains unknown. METHODS: We conducted a double-blind, randomized, 24-month trial comparing the effects of daily therapy with 80 mg of simvastatin either with placebo or with 10 mg of ezetimibe in 720 patients with familial hypercholesterolemia. Patients underwent B-mode ultrasonography to assess the intima-media thickness of the walls of the carotid and femoral arteries. The primary outcome measure was the change in the mean carotid-artery intima-media thickness, which was defined as the average of the means of the far-wall intima-media thickness of the right and left common carotid arteries, carotid bulbs, and internal carotid arteries. RESULTS: The primary outcome, the mean (+/-SE) change in the carotid-artery intima-media thickness, was 0.0058+/-0.0037 mm in the simvastatin-only group and 0.0111+/-0.0038 mm in the simvastatin-plus-ezetimibe (combined-therapy) group (P=0.29). Secondary outcomes (consisting of other variables regarding the intima-media thickness of the carotid and femoral arteries) did not differ significantly between the two groups. At the end of the study, the mean (+/-SD) LDL cholesterol level was 192.7+/-60.3 mg per deciliter (4.98+/-1.56 mmol per liter) in the simvastatin group and 141.3+/-52.6 mg per deciliter (3.65+/-1.36 mmol per liter) in the combined-therapy group (a between-group difference of 16.5%, P

Objective— Functional and morphological changes of the arterial wall already present in young children with heterozygous familial hypercholesterolemia (HeFH) suggest that treatment should be initiated early in life to prevent premature atherosclerotic cardiovascular disease. The purpose of this study was to assess the efficacy and particularly safety of statin therapy in children with HeFH. Methods and Results— We performed a meta-analysis of randomized, double-blind, placebo-controlled trials evaluating statin therapy in children aged 8 to 18 years with HeFH. Six studies (n=798 children) with 12 to 104 weeks of treatment were included. Total cholesterol, LDL cholesterol, and apolipoprotein B were significantly reduced, whereas HDL cholesterol and apolipoprotein A1 were significantly increased by statin therapy. No statistically significant differences were found between statin- and placebo-treated children with respect to the occurrence of adverse events (RR 0.99; 95% CI: 0.79 to 1.25), sexual development (RR of advancing ≥1 stage in Tanner classification 0.96; 95% CI: 0.79 to 1.17), muscle toxicity (RR of CK ≥10 times the upper limit of normal [ULN] 1.38; 95% CI: 0.18 to 10.82), or liver toxicity (RR of ≥3 times the ULN for ASAT 0.98; 95% CI: 0.23 to 4.26 and for ALAT 2.03; 95% CI: 0.24 to 16.95). We found a minimal difference in growth in favor of the statin group (0.33 cm; 95% CI: 0.03 cm to 0.63 cm). Conclusion— In addition to the fact that statin treatment is efficacious, our results support the notion that statin treatment in children with HeFH is safe. Thus, even though further studies are required to assess lifelong safety, statin treatment should be considered for all children aged 8 to 18 with HeFH.

Objective To examine the effect of plant stanols on lipids and endothelial function in pre-pubertal children with familial hypercholesterolemia (FH). Study design Children with FH (n = 42), aged 7-12 years, were enrolled in a double-blind crossover trial, in which they consumed 500 mL of a low-fat yogurt enriched with 2.0 g of plant stanols and 500 mL of a low-fat placebo yogurt for 4 weeks, separated by a 6-week washout period. Lipid profiles and endothelial function were assessed after both consumption periods. Endothelial function was measured as flow-mediated dilation (FMD) of the brachial artery. Results This daily intake of 2.0 g of stanols significantly decreased the levels of total cholesterol (TC) by 7.5% and low-density lipoprotein cholesterol (LDL-C) by 9.2% as compared with placebo. High-density lipoprotein cholesterol and triglyceride levels remained unaltered. The reduction of LDL-C levels did not improve FMD, which was 10.5% ± 5.1% after plant stanol consumption and 10.6% ± 5.0% after placebo consumption, respectively ( P = .852). Conclusion This study demonstrates that plant stanols reduce LDL-C levels in children with FH without improving endothelial function.

Consumption of plant sterols and treatment with ezetimibe both reduce cholesterol absorption in the intestine. However, the mechanism of action differs between the two treatments, and the consequences of combination treatment are unknown. Therefore, we performed a double-blind, placebo-controlled, crossover study for the plant sterol component with open-label ezetimibe treatment. Forty mildly hypercholesterolemic subjects were randomized to the following treatments for 4 weeks each: 10 mg/day ezetimibe combined with 25 g/day control spread; 10 mg/day ezetimibe combined with 25 g/day spread containing 2.0 g of plant sterols; 25 g/day spread containing 2.0 g of plant sterols; and placebo treatment consisting of 25 g/day control spread. Combination treatment of plant sterols and ezetimibe reduced low density lipoprotein cholesterol (LDL-C) by 1.06 mmol/l (25.2%; P < 0.001) compared with 0.23 mmol/l (4.7%; P = 0.006) with plant sterols and 0.94 mmol/l (22.2%; P < 0.001) with ezetimibe monotherapy. LDL-C reduction conferred by the combination treatment did not differ significantly from ezetimibe monotherapy (-0.12 mmol/l or -3.5%; P = 0.13). Additionally, the plasma lathosterol-to-cholesterol ratio increased with all treatments. Sitosterol and campesterol ratios increased after plant sterol treatment and decreased upon ezetimibe and combination therapy. Our results indicate that the combination of plant sterols and ezetimibe has no therapeutic benefit over ezetimibe monotherapy in subjects with mild hypercholesterolemia.

The inhibition of cholesteryl ester transfer protein (CETP) has recently been shown to effectively increase high-density lipoprotein (HDL) cholesterol. This study examined the use of the CETP inhibitor JTT-705 combined with pravastatin. In a randomized, double-blind, placebo-controlled trial, 155 patients with type II dyslipidemia using pravastatin 40 mg were treated with placebo or JTT-705 300 or 600 mg. Four weeks of treatment with JTT-705 600 mg led to a 30% decrease in CETP activity (p

High plasma low-density lipoprotein cholesterol (LDL-C) is a risk factor for the development of atherosclerosis and subsequently, cardiovascular disease (CVD). This epidemiological relationship is highlighted by the early expression of coronary disease in patients with inherited dyslipidemia. In the general population, pharmacological reductions in plasma LDL-C reduce cardiovascular morbidity and mortality significantly. Our understanding of the underlying disease mechanisms in inherited hypercholesterolemia is leading the way to the discovery of new targets for the management of hypercholesterolemia per se . In fact, new options for lipid management are currently being developed for clinical use. Several new key therapies are presented in this review.

Item does not contain fulltext BACKGROUND: Raised plasma lipoprotein(a) (Lp(a)) is associated with increased risk of cardiovascular disease. It is unknown whether increased Lp(a) is an additional risk factor for coronary artery disease in familial hypercholesterolaemia (FH) or whether statin treatment can reduce Lp(a) concentrations in the long term. OBJECTIVE: To investigate Lp(a) concentrations in relation to statin treatment and the progression of atherosclerosis in a large cohort of FH patients. DESIGN: A two year, randomised, double blind trial (the ASAP trial). PATIENTS: 325 heterozygous FH patients. INTERVENTION: Treatment with 80 mg atorvastatin or 40 mg simvastatin. MAIN OUTCOME MEASURE: Change in Lp(a) concentrations and intima-media thickness of carotid artery segments at one year and two years. RESULTS: At baseline, median Lp(a) concentrations were 327 mg/l and 531 mg/l in the atorvastatin and simvastatin arms, respectively (p = 0.03). In the atorvastatin arm, Lp(a) concentrations decreased to 243 mg/l after one year (p < 0.001) and to 263 mg/l after two years (p < 0.001). In the simvastatin arm, Lp(a) concentrations decreased to 437 mg/l after one year (p < 0.001) and to 417 mg/l after two years (p < 0.001). The difference in Lp(a) reduction between the two treatment arms was significant after one year (p = 0.004), but not after two years (p = 0.086). Lp(a) concentrations at baseline were not related to cardiovascular events at baseline. There was no correlation between baseline Lp(a) concentrations and low density lipoprotein cholesterol concentrations or intima-media thickness at baseline. Change in Lp(a) concentrations was not correlated with change in intima-media thickness after one or two years. CONCLUSIONS: Long term statin treatment significantly lowers Lp(a) in FH patients. However, this reduction was unrelated to changes in intima-media thickness and casts doubt on the importance of Lp(a) in the progression of atherosclerotic disease in these patients.

Background: High sensitivity C-reactive protein (hs-CRP) has emerged as the best studied and most promising marker of inflammation in atherosclerotic vascular disease. Materials and methods: The ASAP (effects of Atorvastatin vs. Simvastatin on Atherosclerosis Progression) study was a 2-year randomised, double-blind trial with 325 familial hypercholesterolemia patients, treated with torvastatin 80 mg or imvastatin 40 mg. Intima media thickness (IMT) of carotid artery segments and hs-CRP levels were determined at baseline, 1 and 2 years. Results: Baseline median hs-CRP values were 2.1 mg/l (interquartile range (IQR) 0.9-5.2) and 2.0 mg/l (IQR 0.8-3.0) and after 2 years these levels decreased to 1.1 mg/l (IQR 0.6-2.4) and 1.5 mg/l (IQR 0.6-3.0) in the atorvastatin 80 mg and sinivastatin 40 mg group, respectively. These changes were significant within as well as between the two groups. No correlations were observed between change in hs-CRP after 2 years and change in lipids. A significant correlation was found in univariate analysis between the decrease of hs-CRP and the reduction of IMT. Conclusions: Our results show that atorvastatin 80 mg reduces hs-CRP levels to a greater extent than sinivastatin 40 mg. Furthermore, we show that the extent of hs-CRP reduction is associated with the progression rate of the atherosclerotic process as measured by IMT. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved

AIMS\nGenetic factors explain a proportion of the inter-individual variation in the risk for atherosclerotic events, but the genetic basis of atherosclerosis and atherothrombosis in families with Mendelian forms of premature atherosclerosis is incompletely understood. We set out to unravel the molecular pathology in a large kindred with an autosomal dominant inherited form of premature atherosclerosis.\nMETHODS AND RESULTS\nParametric linkage analysis was performed in a pedigree comprising 4 generations, of which a total of 11 members suffered from premature vascular events. A parametric LOD-score of 3.31 was observed for a 4.4 Mb interval on chromosome 12. Upon sequencing, a non-synonymous variant in KERA (c.920C>G; p.Ser307Cys) was identified. The variant was absent from nearly 28,000 individuals, including 2,571 patients with premature atherosclerosis. KERA, a proteoglycan protein, was expressed in lipid-rich areas of human atherosclerotic lesions, but not in healthy arterial specimens. Moreover, KERA expression in plaques was significantly associated with plaque size in a carotid-collar Apoe-/- mice (r2 = 0.69; p

BACKGROUND: Use of cholesterol-lowering regimens has been shown to reduce the risk of coronary heart disease (CHD), both in primary and secondary prevention. However, there have been few studies of the relative benefits and risks of the various cholesterol-lowering agents in patient groups with specific risk factors for CHD. OBJECTIVE: The primary goal of this study was to compare the proportions of adult patients with primary hypercholesterolemia and a moderate to high risk for CHD achieving National Cholesterol Education Program low-density lipoprotein cholesterol (LDL-C) goals with titrate-to-goal regimens of simvastatin and fluvastatin. METHODS: This was a multicenter, prospective, randomized, double-blind, parallel-group study enrolling adult patients with type IIa or IIb primary hypercholesterolemia, LDL-C levels

To compare the effects of concentrated n-3 fatty acids (Omacor™) and gemfibrozil in patients with severe hypertriglyceridaemia. The primary objective was to measure the change in serum triglyceride (TG), and the secondary objectives were to study the changes in total cholesterol (TC), high density lipoprotein cholesterol (HDL-C), very low density lipoprotein cholesterol (VLDL-C), apolipoproteins and free fatty acids. 89 patients with severe hypertriglyceridaemia (defined as plasma TG >4.5 mmol/L) were randomised to receive in a double-blind fashion either Omacor™, a capsule containing the n-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) at a dosage of 4 g/day, or gemfibrozil 1200 mg/day for 12 weeks. The baseline characteristics of the two randomised groups were similar. Compared with baseline, n-3 fatty acids and gemfibrozil reduced mean TG levels by 28.9 and 51.2%, respectively (p = 0.007). TC was decreased 10.2% with n-3 fatty acids, and 13.0% with gemfibrozil (p = 0.51), and VLDL-C was reduced 11.8 and 19.4% (p = 0.49) with n-3 fatty acids and gemfibrozil, respectively. HDL-C was increased by both compounds; n-3 fatty acids elevated HDL-C by only 1.2%, whereas it was elevated 27.9% by gemfibrozil (p = 0.012). Our study indicated that both n-3 fatty acids and gemfibrozil markedly decreased TG levels in patients with severe hypertriglyceridaemia. Gemfibrozil, however, decreased TG levels and increased HDL-C significantly more than n-3 fatty acids.

Objectives: This single-blind, multicentre study in a large cohort of hypercholesterolaemic patients with or without coronary heart disease (CHD) was designed to evaluate the additional low density lipoprotein cholesterol (LDL-C)— lowering effect of atorvastatin over milligram-equivalent doses of simvastatin. Methods: 378 patients treated with either simvastatin 20 or 40mg, with baseline LDL-C values >2.6 mmol/L, were randomised to four groups: patients on 20mg simvastatin were randomised to either simvastatin 20mg (n = 129) or atorvastatin 20mg (n = 124), and patients on 40mg simvastatin were randomised to simvastatin 40mg (n = 64) or atorvastatin 40mg (n = 61). The investigator was blinded for study medication during the 8-week treatment phase, the patient was not. Lipid profiles were measured at screening, randomisation and at study completion. The primary efficacy parameter was the relative change in LDL-C level within and between groups. Statistical significance was assessed with analysis of variance. Results: No major differences in baseline patient characteristics were found with regard to demographic variables, vital signs, cardiovascular risk factors, concomitant medication or lipid profiles. The mean (±SD) relative decreases of LDL-C from baseline were: 14.0 ± 14.1% for atorvastatin 20mg (n = 107) versus 3.3 ± 14.1% for simvastatin 20mg (n = 108) [p = 0.0001], and 14.7 ± 15.2% for atorvastatin 40mg (n = 55) versus 2.9 ± 12.7% for simvastatin 40mg (n = 54) [p = 0.0001]. The relative change of LDL-C from baseline in the overall atorvastatin group (n = 162) versus the overall simvastatin group (n = 162) was 14.2 ± 14.4% versus 3.2 ± 13.6% (p = 0.0001). This involved an additional decrease of 11% in the atorvastatin versus the simvastatin group. The percentage of high risk patients according to the European Atherosclerosis Society/National Cholesterol Education Program (EAS/NCEP) who initially did not meet these goals but reached them at week 8, was 48/34% (for atorvastatin 20mg) versus 20/14% (for simvastatin 20mg) [p = 0.005 and p = 0.007, respectively], and 58/18% (for atorvastatin 40mg) versus 24/10% (for simvastatin 40mg) [p = 0.005 and not significant, respectively]. Conclusion: Our results indicated that patients with hypercholesterolaemia on simvastatin 20 or 40mg who are switched to a milligram-equivalent dose of atorvastatin, will reach significantly lower LDL-C values within 8 weeks of treatment, with a greater percentage of high risk patients reaching their EAS or NCEP targets.

Objective: Hypercholesterolaemia is strongly associated with increased vessel wall thickness as measured by ultrasound. The question is whether aggressive cholesterol lowering with high-dose atorvastatin can alter intima media thickening to a greater extent than conventional therapy in patients with familial hypercholesterolaemia (FH). The baseline characteristics of a double-blind, randomised trial are described to determine whether two active treatments (high-dose atorvastatin 80mg versus conventional dose simvastatin 40mg), administered over a period of 2 years, may retard the process of intima media thickening in the carotid and femoral arteries of patients with FH. Design and Patients: 325 patients with FH were randomised. Patients entered an 8-week placebo period in which all lipid-lowering medication was discontinued. Thereafter, baseline measurements of lipoprotein parameters and intima media thickness (IMT) of carotid and femoral artery were performed. Results: Baseline low density lipoprotein (LDL) cholesterol (±SD) levels were 8.11 ± 1.92 mmol/L (312 ± 73 mg/dl) in men and 8.22 ± 1.91 mmol/L (316 ± 73 mg/dl) in women, respectively. Mean posterior wall IMT in the left common carotid artery (CCA) was significantly greater in men (0.94 ± 0.29mm) compared with women (0.85 ± 0.20) [p < 0.05]. A similar difference was found for the internal carotid artery (ICA). In the carotid bifurcation, IMT was 1.20 ± 0.50mm in men and 1.1 ± 0.54mm in women. The IMT of the common femoral artery (CFA) was 2.03 ± 0.88mm in men with cardiovascular disease (CVD) and 1.63 ± 0.70mm in men without CVD (p < 0.05). Strikingly, plaques were present in all men and 95% of the women with CVD. The cholesterol-year score and HDL cholesterol levels partially explained the variation in IMT in the carotid bifurcation, whereas gender and smoking contributed to the variation in IMT in the CFA in this group of patients. Conclusion: The patients participating in the Atorvastatin and Simvastatin on Atherosclerosis Progression (ASAP) trial constitute the largest well-documented FH population exhibiting marked increases in IMT of both carotid and femoral arteries and a very high prevalence of plaques, indicating extreme CVD risk. Since lipid-lowering therapy provides the highest benefit in precisely such patients, the ASAP trial will help assess whether aggressive LDL cholesterol intervention leads to retardation of subclinical atherosclerosis progression, as estimated with ultrasonographically assessed IMT.

BACKGROUND Cranial irradiation for children with brain tumors frequently leads to neuroendocrine deficiencies. In this controlled study, the authors investigated risk factors for cardiovascular disease (CVD) for long term survivors of childhood brain cancer. They also tested whether the presence of these risk factors was related to endocrine status. METHODS In 26 survivors of childhood brain cancer (mean age, 25.8 years; mean posttreatment interval, 16 years) and 29 healthy controls (mean age, 27.7 years), the blood pressure, smoking habits, body mass index (BMI), and waist/hip (W/H) ratio were determined. Lipids and lipoproteins were measured and endocrine function was assessed. Carotid intima-media thickness (IMT) measurements were performed by high resolution ultrasonography. RESULTS In the survivors of childhood brain cancer, systolic blood pressure and W/H ratio were elevated compared with controls. The cholesterol/high density lipoprotein ratio (4.7 ± 1.7 vs. 3.4 ± 0.8 mmol/L, P = 0.0005), low density lipoprotein cholesterol level (3.3 ± 0.9 vs. 2.8 ± 0.6 mmol/L, P = 0.027), and apolipoprotein B level (P = 0.001) were higher in survivors of childhood brain cancer, whereas HDL cholesterol was lower (P = 0.005). The IMT was increased in the survivor group, but only in the carotid bulb (0.63 mm ± 1.6 vs. 0.53 mm ± 1.1, P = 0.02), not in the internal or common carotid artery. In the absolute growth hormone deficient (GHD) population (n = 9), LDL cholesterol and apolipoprotein B levels were elevated and the W/H ratio was particularly increased compared with the other survivors of childhood brain cancer. CONCLUSIONS For long term survivors of brain cancer, the risk for CVD is strongly increased due to dyslipidemia, central obesity, and elevated systolic blood pressure, particularly for those with GHD. The first effects of this increased risk for CVD were observed in the carotic bulb, as assessed by IMT measurements. Efforts should be directed at CVD prevention by risk factor control. Cancer 2000;88:2116–21. © 2000 American Cancer Society.

Abstract —The D9N substitution is a common mutation in the lipoprotein lipase (LPL) gene. This mutation has been associated with reduced levels of HDL cholesterol and elevated triglycerides (TG) in a wide variety of patients. We investigated the influence of this D9N mutation on lipid and lipoprotein levels and risk for cardiovascular disease (CVD) in patients with familial hypercholesterolemia (FH). A total of 2091 FH heterozygotes, all of Dutch extraction, were screened for the D9N mutation using standard polymerase chain reaction techniques, followed by specific enzyme digestion. A total of 94 FH subjects carrried the D9N mutation at a carrier frequency of 4.5%. Carriers of other common LPL mutations, such as the N291S and the S447X were excluded. Clinical data on 80 FH individuals carrying the D9N were available and were compared with a FH control group matched for age, sex, and body mass index (n=203). Analysis revealed significantly higher TG ( P =0.01) and lower HDL-cholesterol levels ( P =0.002). Dyslipidemia was more pronounced in D9N carriers with higher body mass index. Moreover, FH patients carrying this common LPL mutation were at higher risk for CVD, (odds ratio=2.8; 95% CI, 1.43 to 5.32; P =0.002). The common D9N LPL mutation leads to increased TG and decreased HDL plasma levels in patients with FH. These effects are most apparent in those FH heterozygotes with an increased body mass index. Furthermore, this mutation, present in 4.5% of Dutch FH heterozygotes, leads to increased risk for CVD.

It is unknown whether the variation in severity of cardiovascular disease (CVD), seen in patients with familial hypercholesterolemia (FH), is reflected in the intima-media thickness (IMT) of carotid and femoral arteries. We measured IMT in both these arteries in 248 consecutive patients with FH, attending our Lipid Clinic. One hundred and six patients were classified as having CVD, while the remaining FH subjects had no clinical evidence of CVD. IMT measurements of 20 prespecified carotid and femoral arterial wall segments of the FH groups with and without CVD were compared. All IMTs in both groups were severely thickened with respect to normal controls. Furthermore, the highest IMTs and the largest absolute differences were observed in the common femoral artery (1.23 +/- 0.46 mm vs 1.10 +/- 0.51 mm; P = 0.006). In subjects with CVD, the distributions of IMT within tertiles for both arterial segments were opposite to those found in FH patients without CVD, (P

An increased total plasma homocysteine level is an established risk factor for atherosclerotic vascular disease. The plasma level of homocysteine is influenced by both environmental and genetic factors. An important genetic determinant of plasma homocysteine is a common amino acid dimorphism (Ala222Val) in the methylenetetrahydrofolate reductase (MTHFR) gene. Individuals homozygous for the Val allele have significantly higher homocysteine levels than those with an Ala/Val or Ala/Ala genotype. Moreover, the Val/Val genotype has been claimed to be a strong genetic risk factor for atherosclerosis. The aim of the present study is: (1) to determine the risk associated with the MTHFR dimorphism by comparing the genotype distribution in patients with premature atherosclerosis with that in a group of healthy controls; and (2) to investigate the relationship between the MTHFR genotype and parameters of homocysteine metabolism. The patient group consisted of 257 consecutive referred individuals with angiographically proven premature (

Various studies (1–16) in recent years have reported that the metabolic syndrome is associated with an increase in cardiovascular disease (CVD). However, there is still an uncertainty about the clinical importance and consequences of the metabolic syndrome (17). There is paucity of data looking at the effect of metabolic syndrome, specifically on cerebrovascular (CeVD) (9,12,18,19) and peripheral vascular (PVD) disease. Heterozygous familial hypercholesterolemia (FH) is a common hereditary disorder of lipoprotein metabolism (prevalence 1:400). The disorder is caused by mutations in the LDL receptor gene. The objective of our study was to assess if there was an additional risk associated with the presence of metabolic syndrome for coronary disease, CeVD, and PVD in this high-risk population, which included patients inducted from 27 clinics around the Netherlands. The database for the current study is the molecular diagnostic center for nationwide FH screening in the Netherlands, located at the Academic Medical Centre, University of Amsterdam. A total of 2,400 patients fulfilled the diagnostic criteria for FH and were included in the study. The inclusion and exclusion criteria for participation in the study and details of the data collection are outlined and previously discussed in detail (20–22). The ethics institutional review board of each participating hospital approved …

Objectives:\ud This study sought to investigate the role of secretory phospholipase A2 (sPLA2)-IIA in cardiovascular disease.\ud \ud Background:\ud Higher circulating levels of sPLA2-IIA mass or sPLA2 enzyme activity have been associated with increased risk of cardiovascular events. However, it is not clear if this association is causal. A recent phase III clinical trial of an sPLA2 inhibitor (varespladib) was stopped prematurely for lack of efficacy.\ud \ud Methods:\ud We conducted a Mendelian randomization meta-analysis of 19 general population studies (8,021 incident, 7,513 prevalent major vascular events [MVE] in 74,683 individuals) and 10 acute coronary syndrome (ACS) cohorts (2,520 recurrent MVE in 18,355 individuals) using rs11573156, a variant in PLA2G2A encoding the sPLA2-IIA isoenzyme, as an instrumental variable.\ud \ud Results:\ud PLA2G2A rs11573156 C allele associated with lower circulating sPLA2-IIA mass (38% to 44%) and sPLA2 enzyme activity (3% to 23%) per C allele. The odds ratio (OR) for MVE per rs11573156 C allele was 1.02 (95% confidence interval [CI]: 0.98 to 1.06) in general populations and 0.96 (95% CI: 0.90 to 1.03) in ACS cohorts. In the general population studies, the OR derived from the genetic instrumental variable analysis for MVE for a 1-log unit lower sPLA2-IIA mass was 1.04 (95% CI: 0.96 to 1.13), and differed from the non-genetic observational estimate (OR: 0.69; 95% CI: 0.61 to 0.79). In the ACS cohorts, both the genetic instrumental variable and observational ORs showed a null association with MVE. Instrumental variable analysis failed to show associations between sPLA2 enzyme activity and MVE.\ud \ud Conclusions:\ud Reducing sPLA2-IIA mass is unlikely to be a useful therapeutic goal for preventing cardiovascular events.

Approaches exploiting trait distribution extremes may be used to identify loci associated with common traits, but it is unknown whether these loci are generalizable to the broader population. In a genome-wide search for loci associated with the upper versus the lower 5th percentiles of body mass index, height and waist-to-hip ratio, as well as clinical classes of obesity, including up to 263,407 individuals of European ancestry, we identified 4 new loci (IGFBP4, H6PD, RSRC1 and PPP2R2A) influencing height detected in the distribution tails and 7 new loci (HNF4G, RPTOR, GNAT2, MRPS33P4, ADCY9, HS6ST3 and ZZZ3) for clinical classes of obesity. Further, we find a large overlap in genetic structure and the distribution of variants between traits based on extremes and the general population and little etiological heterogeneity between obesity subgroups. © 2013 Nature America, Inc. All rights reserved.

Ga je medisch-wetenschappelijk onderzoek doen met mensen, dan is het belangrijk dat je weet welke specifieke verantwoordelijkheid je als klinisch onderzoeker hebt en aan welke wetten en regels je gebonden bent. Ga je onderzoek doen met patienten uit het ziekenhuis, dan is er een aantal vragen die beantwoord moeten worden. Hoe ga je hen benaderen, hen informeren en toestemming vragen? Hoe ga je om met privacy, hoe is de verzekering geregeld? Ga je onderzoek doen met geneesmiddelen of medische hulpmiddelen, dan moet je gedegen kennis hebben van je onderzoeksproduct. Ga je gebruikmaken van laboratorium- of beeldvormende technieken, dan moet je weten hoe de kwaliteitscontrole hiervan geregeld is. Dit alles leer je in de BROK, de Basiscursus Regelgeving en Organisatie voor Klinisch onderzoekers.

To extend understanding of the genetic architecture and molecular basis of type 2 diabetes (T2D), we conducted a meta-analysis of genetic variants on the Metabochip, including 34,840 cases and 114,981 controls, overwhelmingly of European descent. We identified ten previously unreported T2D susceptibility loci, including two showing sex-differentiated association. Genome-wide analyses of these data are consistent with a long tail of additional common variant loci explaining much of the variation in susceptibility to T2D. Exploration of the enlarged set of susceptibility loci implicates several processes, including CREBBP-related transcription, adipocytokine signaling and cell cycle regulation, in diabetes pathogenesis. © 2012 Nature America, Inc. All rights reserved.

To identify genetic factors contributing to type 2 diabetes (T2D), we performed large-scale meta-analyses by using a custom ∼50,000 SNP genotyping array (the ITMAT-Broad-CARe array) with ∼2000 candidate genes in 39 multiethnic population-based studies, case-control studies, and clinical trials totaling 17,418 cases and 70,298 controls. First, meta-analysis of 25 studies comprising 14,073 cases and 57,489 controls of European descent confirmed eight established T2D loci at genome-wide significance. In silico follow-up analysis of putative association signals found in independent genome-wide association studies (including 8,130 cases and 38,987 controls) performed by the DIAGRAM consortium identified a T2D locus at genome-wide significance (GATAD2A/CILP2/PBX4; p = 5.7 × 10 -9) and two loci exceeding study-wide significance (SREBF1, and TH/INS; p < 2.4 × 10 -6). Second, meta-analyses of 1,986 cases and 7,695 controls from eight African-American studies identified study-wide-significant (p = 2.4 × 10 -7) variants in HMGA2 and replicated variants in TCF7L2 (p = 5.1 × 10 -15). Third, conditional analysis revealed multiple known and novel independent signals within five T2D-associated genes in samples of European ancestry and within HMGA2 in African-American samples. Fourth, a multiethnic meta-analysis of all 39 studies identified T2D-associated variants in BCL2 (p = 2.1 × 10 -8). Finally, a composite genetic score of SNPs from new and established T2D signals was significantly associated with increased risk of diabetes in African-American, Hispanic, and Asian populations. In summary, large-scale meta-analysis involving a dense gene-centric approach has uncovered additional loci and variants that contribute to T2D risk and suggests substantial overlap of T2D association signals across multiple ethnic groups. © 2012 The American Society of Human Genetics.

Background— Pseudoxanthoma elasticum (PXE) is an inborn disorder of the connective tissue with specific skin, ocular, and cardiovascular disease (CVD) manifestations. Recently, we and others have identified mutations in the gene coding for the ABCC6 transporter in PXE patients with ocular and skin involvement. In the Netherlands, as in the rest of Europe, a particular premature truncation variant ABCC6 (R1141X) was found in a large cohort of PXE patients. Given the association between CVD and PXE, we hypothesized that heterozygosity of this ABCC6 mutation could also confer an increased risk for CVD. Methods and Results— To assess the relationship between the frequent R1141X mutation in the ABCC6 gene and the prevalence of premature coronary artery disease (CAD), we conducted a case-control study of 441 patients under the age of 50 years who had definite CAD and 1057 age- and sex-matched population-based controls who were free of coronary disease. Strikingly, the prevalence of the R1141X mutation was 4.2 times higher among patients than among controls (3.2% versus 0.8%; P P = 0.001). Conclusion— The presence of the R1141X mutation in the ABCC6 gene is associated with a sharply increased risk of premature CAD.

Objective A positive family history of premature coronary artery disease (CAD) is a risk factor for cardiovascular disease (CVD), independent of traditional risk factors. Therefore, currently used risk algorithms poorly predict risk in these individuals. Novel methods are thus needed to assess cardiovascular risk. Pulse-wave velocity (PWV) might be such a method, but it is unknown whether PWV is increased in first-degree relatives of patients with premature CAD. Design Observational case-control study. Setting Academic hospital. Patients Patients with premature CAD and a positive family history of premature CVD (n = 50), their first-degree relatives without CVD (n = 50) and unrelated controls (n = 50). Interventions None. Main Outcome Measures PWV was measured with using an Arteriograph system. Differences in PWV were assessed by a generalised linear model and multinomial logistic regression. Results Patients with premature CAD had a higher PWV compared with first-degree relatives and controls (9.69+/-2.90 m/s vs 8.15+/-61.96 m/s and 7.38+/-61.08 m/s; p

Turning genetic discoveries identified in genome-wide association (GWA) studies into biological mechanisms is an important challenge in human genetics. Many GWA signals map outside exons, suggesting that the associated variants may lie within regulatory regions. We applied the formaldehyde-assisted isolation of regulatory elements (FAIRE) method in a megakaryocytic and an erythroblastoid cell line to map active regulatory elements at known loci associated with hematological quantitative traits, coronary artery disease, and myocardial infarction. We showed that the two cell types exhibit distinct patterns of open chromatin and that cell-specific open chromatin can guide the finding of functional variants. We identified an open chromatin region at chromosome 7q22.3 in megakaryocytes but not erythroblasts, which harbors the common non-coding sequence variant rs342293 known to be associated with platelet volume and function. Resequencing of this open chromatin region in 643 individuals provided strong evidence that rs342293 is the only putative causative variant in this region. We demonstrated that the C- and G-alleles differentially bind the transcription factor EVI1 affecting PIK3CG gene expression in platelets and macrophages. A protein–protein interaction network including up- and down-regulated genes in Pik3cg knockout mice indicated that PIK3CG is associated with gene pathways with an established role in platelet membrane biogenesis and thrombus formation. Thus, rs342293 is the functional common variant at this locus; to the best of our knowledge this is the first such variant to be elucidated among the known platelet quantitative trait loci (QTLs). Our data suggested a molecular mechanism by which a non-coding GWA index SNP modulates platelet phenotype., Author Summary Genome-wide scans have revealed multiple genetic regions underlying complex traits. However, the transition from an initial association signal to identifying the functional DNA change(s) has proved challenging. Many of the DNA changes discovered are located outside protein-coding regions and may exert their effects through gene regulation. We screened genetic regions associated with hematological traits in erythroblasts (red blood cells) and megakaryocytes (platelet-producing cells) and mapped sites of open chromatin, which harbor active gene regulatory elements. We investigated a DNA sequence change located within a site of open chromatin at chromosome 7 in megakaryocytes, but not erythroblasts, known to be associated with platelet volume. We showed that this DNA change is functional due to alteration of the binding site of a transcription factor, which regulates the expression of a gene that affects platelet characteristics. Mice lacking this gene revealed significant differences in expression of several important platelet genes compared to wild-type mice. The approach described here can be applied in different cell types to functionally follow-up association signals with many other biological traits by identification of the causative base change and how it affects gene function, thus paving the way to clinical benefit.

BackgroundCoronary artery disease (CAD) is the leading cause of human morbidity and mortality worldwide, underscoring the need to improve diagnostic strategies. Platelets play a major role, not only in the process of acute thrombosis during plaque rupture, but also in the formation of atherosclerosis itself. MicroRNAs are endogenous small non-coding RNAs that control gene expression and are expressed in a tissue and disease-specific manner. Therefore they have been proposed to be useful biomarkers. It remains unknown whether differences in miRNA expression levels in platelets can be found between patients with premature CAD and healthy controls.Methodology/principal findingsIn this case-control study we measured relative expression levels of platelet miRNAs using microarrays from 12 patients with premature CAD and 12 age- and sex-matched healthy controls. Six platelet microRNAs were significantly upregulated (miR340*, miR451, miR454*, miR545:9.1. miR615-5p and miR624*) and one miRNA (miR1280) was significantly downregulated in patients with CAD as compared to healthy controls. To validate these results, we measured the expression levels of these candidate miRNAs by qRT-PCR in platelets of individuals from two independent cohorts; validation cohort I consisted of 40 patients with premature CAD and 40 healthy controls and validation cohort II consisted of 27 patients with artery disease and 40 healthy relatives. MiR340* and miR624* were confirmed to be upregulated in patients with CAD as compared to healthy controls in both validation cohorts.Conclusion/significanceTwo miRNAs in platelets are significantly upregulated in patients with CAD as compared to healthy controls. Whether the two identified miRNAs can be used as biomarkers and whether they are cause or consequence of the disease remains to be elucidated in a larger prospective study.

Background: It is widely accepted that atherosclerosis and inflammation are intimately linked. Monocytes play a key role in both of these processes and we hypothesized that activation of inflammatory pathways in monocytes would lead to, among others, proatherogenic changes in the monocyte transcriptome. Such differentially expressed genes in circulating monocytes would be strong candidates for further investigation in disease association studies, Methods: Endotoxin, lipopolysaccharide (LPS), or saline control was infused in healthy volunteers. Monocyte RNA was isolated, processed and hybridized to Hver 2.1.1 spotted cDNA microarrays. Differential expression of key genes was confirmed by RT-PCR and results were compared to in vitro data obtained by our group to identify candidate genes, Results: All subjects who received LPS experienced the anticipated clinical response indicating successful stimulation. One hour after LPS infusion, 11 genes were identified as being differentially expressed; 1 down regulated and 10 up regulated. Four hours after LPS infusion, 28 genes were identified as being differentially expressed; 3 being down regulated and 25 up regulated. No genes were significantly differentially expressed following saline infusion. Comparison with results obtained in in vitro experiments lead to the identification of 6 strong candidate genes (BATF, BID, C3aR1, IL1RN, SEC61B and SLC43A3), Conclusion: In vivo endotoxin exposure of healthy individuals resulted in the identification of several candidate genes through which systemic inflammation links to atherosclerosis., peer-reviewed