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AIMS: To assess whether adding anthropometric measurements to an oral glucose tolerance test (OGTT) can help to distinguish between transient and persistent impaired glucose tolerance (IGT). METHODS: From the SLIM project (Study on Lifestyle-Intervention and IGT Maastricht), a study designed to evaluate whether diet and physical activity intervention can improve glucose tolerance in subjects at risk for diabetes, 108 subjects with IGT underwent a repeated OGTT 2-4 months after the initial OGTT. Following the second test, subjects were classified as transient IGT, or persistent IGT. Anthropometric measurements, including body mass index, waist and hip circumference, sagittal and transverse abdominal diameters and skinfold thickness measurements, were done during the second OGTT. RESULTS: Persistent IGT was diagnosed in 47 subjects (44%), transient IGT in 40 (37%), impaired fasting glucose in eight subjects (7%), and diabetes in 13 cases (12%). Two-hour blood glucose levels at the initial OGTT and subscapular skinfold thickness were significantly higher in subjects with persistent IGT (2-h blood glucose 9.8+/-0.1 mmol/l vs. 10.2+/-0.1 mmol/l for transient IGT and persistent IGT, respectively; subscapular skinfold thickness 25.4+/-1.4 mm vs. 29.8+/-1.2 mm for transient IGT and persistent IGT, respectively). After adjustment for age, sex and family history of diabetes mellitus, logistic regression indicated that 2-h blood glucose level during the initial OGTT represented the strongest predictor of persistent IGT (P<0.02), followed by subscapular skinfold thickness (P<0.05). After adjustment for 2-h blood glucose levels during the first OGTT, subscapular skinfold thickness remained significantly associated with persistent IGT (odds ratio 1.84; P<0.05). CONCLUSIONS: In addition to the 2-h blood glucose level, subscapular skinfold thickness was the best predictor of persistent IGT, suggesting that adding simple anthropometric measures to oral glucose tolerance testing may improve the distinction between persistent and transient glucose intolerance. [ABSTRACT FROM AUTHOR]

Aim: To evaluate the long-term efficacy, safety and tolerability of dapagliflozin versus placebo added to usual care in patients with type 2 diabetes mellitus (T2DM) and cardiovascular disease (CVD)., Methods: Data were pooled from two phase III studies (NCT01031680 and NCT01042977) in high-risk patients (N = 1887) with T2DM and CVD treated with dapagliflozin (10 mg/day) or placebo. Patients completing the double-blind treatment studies (24 weeks) entered one or two sequential double-blind, long-term (LT) extensions of 28 (LT1; n = 1649) and 52 (LT2; n = 568) weeks., Results: Baseline and CVD characteristics were similar in the two groups. Patients entering LT1 and LT2 on dapagliflozin maintained a greater mean reduction in glycated haemoglobin (HbA1c) versus placebo at 52 weeks [LT1, -0.58% (95% confidence interval -0.68, -0.49)] and 104 weeks [LT2, -0.35% (95% confidence interval -0.59, -0.12)]. Mean body weight and systolic blood pressure (SBP) reductions versus placebo were maintained in patients entering LT1 (52 weeks; -2.23 kg and -3.25 mmHg, respectively) and LT2 (104 weeks; -3.16 kg and -2.03 mmHg, respectively). Patients on dapagliflozin had a better three-item composite endpoint of clinical benefit (glycaemia, weight and SBP) compared with placebo at week 24 (LT1, 10.1% vs. 1.1%) and week 104 (LT2, 6.7% vs. 1.4%). Genital and urinary tract infections were more frequent with dapagliflozin than with placebo. Events of hypoglycaemia, renal impairment/failure and volume depletion were similar between groups., Conclusions: The long-term efficacy of dapagliflozin to maintain reductions in HbA1c, SBP and body weight over 2 years, together with its tolerability profile, make dapagliflozin an appropriate option in high-risk patients with T2DM and CVD., (© 2016 John Wiley & Sons Ltd.)

The pharmacokinetics (PK) of dapagliflozin and metformin administered as fixed-dose combination (FDC) tablets (2.5 mg dapagliflozin/850 mg metformin or 5 mg dapagliflozin/1000 mg metformin) or as separate tablets in healthy subjects were evaluated in 2 separate studies. Study 1 evaluated PK by measuring mean ratios of area under the plasma concentration-time curve (time zero to infinity [AUCinf ]), AUC from zero to time of last measurable concentration (AUC0-t ), and maximum observed plasma concentration (Cmax ) for single-component or FDC tablets following a non-high-fat meal. Mean ratios of AUCinf , AUC0-t , and Cmax for FDC or single-component dapagliflozin and metformin tablets were close to unity. In study 2, AUCinf , AUC0-t , and Cmax for the FDC tablet were obtained fasting and after a high-fat meal. Dapagliflozin 5 mg and metformin 1000 mg geometric mean Cmax was increased in the fasted versus fed state (61.9 vs 43.9 and 1600 vs 1330 ng/mL, respectively), but AUC0-t was similar (267 and 265 and 11 000 and 10 600 ng · h/mL, respectively). In summary, FDC tablets were bioequivalent to single-component tablets, and total absorption (AUC) was similar for non-high-fat and high-fat meals., (© 2015, The American College of Clinical Pharmacology.)

Objective: To assess the efficacy and safety of dapagliflozin, a selective sodium-glucose cotransporter 2 inhibitor, compared with placebo in patients with type 2 diabetes (T2D), documented pre-existing cardiovascular disease (CVD), and a history of hypertension., Research Design and Methods: Patients (N = 922) were randomized to receive 10 mg dapagliflozin or placebo in a double-blind trial for 24 weeks, followed by a 28-week extension period. In patients receiving insulin, the insulin dose was reduced by 25% at randomization. Patients were stratified by age, insulin use, and time from the most recent qualifying cardiovascular (CV) event. Co-primary end points were a change from baseline in hemoglobin A1c (HbA1c) and the proportion of patients achieving a combined reduction in HbA1c of ≥0.5% (5.5 mmol/mol), body weight (BW) of ≥3%, and systolic blood pressure (SBP) of ≥3 mmHg., Results: At 24 weeks, dapagliflozin significantly reduced HbA1c (-0.38% [-4.2 mmol/mol]) from baseline (8.18%) compared with a slight increase with placebo from baseline (8.08%) (0.08% [0.9 mmol/mol]). Significantly more patients met the three-item end point with treatment with dapagliflozin than with placebo (11.7% vs. 0.9%, respectively). Changes were maintained over 52 weeks. Although ∼42% of patients were ≥65 years old, similar results were observed in both age-stratified groups. Serious adverse events, hypoglycemia, urinary tract infections, and cardiac disorders were similar between groups. Adverse events of hypotension, dehydration, hypovolemia, genital infection, and renal failure or impairment occurred more often with dapagliflozin treatment., Conclusions: In this study that evaluated T2D patients who were at high risk for future CVD events, dapagliflozin administration had significantly greater effects in reducing HbA1c, BW, and SBP, without adversely impacting CV safety when compared with placebo treatment., (© 2015 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.)

The primary objective of this single-centre, open-label crossover study (NCT01072578) was to assess the effect of dapagliflozin on the amount of glucose in the blood and urine in healthy volunteers when dapagliflozin was administered once a day (10 mg) versus twice a day (5 mg every 12 h) after 5 days of dosing. At steady state, the AUC(ss)₀₋₂₄ (area under the dapagliflozin curve (0-24 hours) at steady state), C(ss,av) (average concentration at steady state) between dapagliflozin 5 mg twice daily and 10 mg once daily were similar AUC(ss)₀₋₂₄ [5 mg bid, (458.0 (28.7)) and 10 mg qd, (470.0 (28.5))] and C(ss,av) [5 mg bid 18.8 (28.9)) and 10 mg qd, (19.6(28.5))], but minimum and maximum plasma levels of dapagliflozin differed significantly. Percent inhibition of renal glucose reabsorption (%IRGRA) and total urinary glucose excretion over 24 h were similar for both doses. The relationship between the mean dapagliflozin concentration and %IRGRA and the total urinary glucose excreted was well described by a maximum effect model. The results indicate that dapagliflozin may be used for either once daily or twice daily administration., (© 2014 John Wiley & Sons Ltd.)

Aims: To evaluate the efficacy and safety of twice-daily dosing of dapagliflozin and metformin, exploring the feasibility of a fixed-dose combination., Methods: In this 16-week, phase III, randomized, double-blind placebo-controlled study, adults who were receiving metformin administered twice daily (≥1500 mg/day) and had inadequate glycaemic control were randomized 1:1:1:1 to receive dapagliflozin twice daily (2.5 or 5 mg), placebo or dapagliflozin 10 mg once daily (which was included as a benchmark). The primary endpoint was change from baseline glycated haemoglobin (HbA1c) level. Secondary endpoints included changes in fasting plasma glucose (FPG) level and body weight., Results: Four hundred adults were randomized to dapagliflozin (2.5 mg twice daily, 5 mg twice daily, 10 mg once daily) or placebo co-administered with metformin twice daily. At 16 weeks, the adjusted mean change in HbA1c from baseline was significantly reduced in the dapagliflozin 2.5 mg twice daily and 5 mg twice daily groups versus placebo (-0.52 vs. -0.30%, p = 0.0106 and -0.65% vs. -0.30%, p < 0.0001). There were also significantly greater improvements for dapagliflozin twice daily groups versus placebo in FPG body weight and achievement of HbA1c level of <7%. Efficacy outcomes for dapagliflozin twice daily were numerically similar to those for dapagliflozin once daily. Dapagliflozin twice daily was well tolerated., Conclusions: Dapagliflozin 2.5 or 5 mg twice daily added to metformin was effective in reducing glycaemic levels in patients with type 2 diabetes inadequately controlled with metformin alone. This study supports the development of a fixed-dose combination regimen., (© 2014 John Wiley & Sons Ltd.)

Background: Dapagliflozin reduces hyperglycaemia in patients with type 2 diabetes mellitus (T2DM) by increasing urinary glucose excretion., Objectives: This study determined the overall safety profile of dapagliflozin in T2DM., Methods: Safety of dapagliflozin in pooled analyses of phase IIb/III studies was evaluated. Patients received comparator or dapagliflozin as monotherapy, add-on to antidiabetic therapy, or as initial combination with metformin. Proportions of patients with adverse events (AEs) and prespecified parameters related to previous clinical observations and dapagliflozin's action were assessed. The principal analysis used data from 12 placebo-controlled studies. Rare events were assessed across phase IIb/III studies, including special populations, comparator-controlled trials and ongoing long-term extensions., Results: In placebo-controlled studies, hypoglycaemia was more common with dapagliflozin (11.8 %) than placebo (7.0 %), with imbalance driven by add-on of dapagliflozin to sulfonylurea or insulin. Urinary tract infections (4.8 vs 3.7 %), vulvovaginitis/balanitis and related infections (5.1 vs 0.9 %), and non-serious volume-related events (0.8 vs 0.4 %) occurred more often with dapagliflozin than placebo. No substantial AEs were seen on electrolytes or renal function. Pyelonephritis was rare and balanced among treatments; there were no imbalances in fractures or liver test elevations. Overall incidence of malignancies was balanced between groups. The incidence rate ratios of malignancy in certain organ systems were slightly lower for dapagliflozin (renal tract, female reproductive) and in others were slightly lower for control (breast, prostate, bladder). Most AEs associated with dapagliflozin were mild/moderate and related to the mechanism of action., Conclusion: Dapagliflozin has a favourable and predictable tolerability profile, with reported events related to its mechanism of action.

Objectives: To assess the efficacy of dapagliflozin, a sodium-glucose cotransporter 2 inhibitor, for the treatment of individuals with type 2 diabetes mellitus (T2DM) and preexisting cardiovascular disease (CVD)., Design: Randomized, double-blind, age-stratified (<65 and ≥ 65), 24-week clinical trial with a 28-week extension., Setting: One hundred seventy-three centers in 10 countries., Participants: Individuals (N = 964) with T2DM, glycosylated hemoglobin (HbA1c) of 7.0% to 10.0%, and documented CVD., Intervention: Dapagliflozin 10 mg/d or placebo was added to usual care. Participants receiving insulin had their total daily insulin dose reduced by 25% at randomization., Measurements: Two equal primary end points: change from baseline in HbA1c and proportion of participants achieving a three-item end point (reduction of ≥ 0.5% in HbA1c, ≥ 3% in body weight, and ≥ 3 mmHg in systolic blood pressure) at 24 weeks., Results: Forty-seven percent were aged 65 and older, 7.7% were aged 75 and older, mean duration of T2DM was 13 years, mean baseline HbA1c was 8.1%, and approximately 60% were taking insulin. The placebo-corrected change in HbA1c with dapagliflozin was -0.4% at 24 weeks. Significantly more participants achieved the three-item end point with dapagliflozin (10.0%) than with placebo (1.9%). The placebo-corrected percentage change in body weight for dapagliflozin was -1.9% (-1.8 kg). Similar results were observed in both age strata, and changes were maintained over 52 weeks. More than one-quarter (28.2%) of participants receiving dapagliflozin and 25.3% of those receiving placebo experienced hypoglycemia. More participants receiving dapagliflozin had vulvovaginitis, balanitis, or urinary tract infection., Conclusion: When added to a usual background regimen in an older population with advanced T2DM and preexisting comorbid CVD, dapagliflozin improved glycemic control without an increase in hypoglycemic risk, promoted weight loss, and was well tolerated., (© 2014, Copyright the Authors Journal compilation © 2014, The American Geriatrics Society.)

Familial combined hyperlipidemia (FCHL) is a common lipid disorder characterized by the presence of multiple lipoprotein phenotypes that increase the risk of premature coronary heart disease. In a previous study, we identified an intragenic microsatellite marker within the protocadherin 15 (PCDH15) gene to be associated with high triglycerides (TGs) in Finnish dyslipidemic families. In this study we analyzed all four known nonsynonymous SNPs within PCDH15 in 1,268 individuals from Finnish and Dutch multigenerational families with FCHL. Association analyses of quantitative traits for SNPs were performed using the QTDT test. The nonsynonymous SNP rs10825269 resulted in a P = 0.0006 for the quantitative TG trait. Additional evidence for association was observed with the same SNP for apolipoprotein B levels (apo-B) (P = 0.0001) and total cholesterol (TC) levels (P = 0.001). None of the other three SNPs tested showed a significant association with any lipid-related trait. We investigated the expression of PCDH15 in different human tissues and observed that PCDH15 is expressed in several tissues including liver and pancreas. In addition, we measured the plasma lipid levels in mice with loss-of-function mutations in Pcdh15 (Pcdh15(av-Tg) and Pcdh15(av-3J)) to investigate possible abnormalities in their lipid profile. We observed a significant difference in plasma TG and TC concentrations for the Pcdh15(av-3J) carriers when compared with the wild type (P = 0.013 and P = 0.044, respectively). Our study suggests that PCDH15 is associated with lipid abnormalities.

Objective: Activating transcription factor 6 (ATF6) is a sensor of the endoplasmic reticulum stress response and regulates expression of several key lipogenic genes. We used a 2-stage design to investigate whether ATF6 polymorphisms are associated with lipids in subjects at increased risk for cardiovascular disease (CVD)., Methods and Results: In stage 1, 13 tag-SNPs were tested for association in Dutch samples ascertained for familial combined hyperlipidemia (FCHL) or increased risk for CVD (CVR). In stage 2, we further investigated the SNP with the strongest association from stage 1, a Methionine/Valine substitution at amino-acid 67, in Finnish FCHL families and in subjects with CVR from METSIM, a Finnish population-based cohort. The combined analysis of both stages reached region-wide significance (P=9 x 10(-4)), but this association was not seen in the entire METSIM cohort. Our functional analysis demonstrated that Valine at position 67 augments ATF6 protein and its targets Grp78 and Grp94 as well as increases luciferase expression through Grp78 promoter., Conclusions: A common nonsynonymous variant in ATF6 increases ATF6 protein levels and is associated with cholesterol levels in subjects at increased risk for CVD, but this association was not seen in a population-based cohort. Further replication is needed to confirm the role of this variant in lipids.

Objective: There is increasing physiological evidence in rodents connecting the neuropeptide galanin to triglyceride (TG) levels. We hypothesized that variation in the galanin preproprotein (GAL) gene may contribute to hypertriglyceridemia (HTG) in humans., Methods and Results: We investigated GAL as a TG candidate gene by genotyping 4 tagSNPs in Dutch, Finnish, and Mexican familial combined hyperlipidemia (FCHL) families as well as in white combined hyperlipidemia cases/controls (n=2471). The common allele of rs2187331, residing in the promoter region of GAL, was significantly associated with HTG (probability value=0.00038). In an unascertained population sample of 4463 Finnish males, the rare allele of rs2187331 was associated with higher TGs (probability value=0.0028 to 0.00016). We also observed an allele specific difference with rs2187331 in reporter gene expression and nuclear factor binding in vitro. Furthermore, we detected differential expression of many key lipid genes in adipose tissue based on rs2187331 genotypes., Conclusions: The SNP rs2187331 is associated with HTG in FCHL and white combined hyperlipidemia cases/controls and influences TG levels in the population. Further studies are warranted to elucidate the allelic difference observed between FCHL and the general population. Functional evidence shows that rs2187331 has an allele specific cis-regulatory function and influences the expression of lipid related genes in adipose.

Aims: Low-density lipoprotein cholesterol (LDL-C) levels are often fairly normal in Type 2 diabetes mellitus (DM). We anticipated that a parabolic relation between plasma triglycerides and LDL-C, as previously demonstrated in familial combined hyperlipidaemia (FCHL), might account for this phenomenon., Methods: Our hypothesis was tested in 1343 subjects derived from the general population who were studied on two occasions 6 years apart (the Hoorn study). Three groups were constructed depending on plasma triglycerides: group A (individuals with both measurements below 1.5 mmol/l), group B (one measurement below and one above 1.5 mmol/l) and group C (both measurements above 1.5 mmol/l). Diabetes status was ascertained by an oral glucose tolerance test., Results: In a mixed linear model, a significant, positive relation between triglycerides and LDL-C was observed for males in group A (beta(a) = 0.5, P < 0.001) and group B (beta(b) = 0.2, P < 0.001), whereas a significant negative relation was found for males in group C (beta(c) = -0.2, P = 0.003). The regression slopes did not differ between diabetic and non-diabetic subjects. Similar results were obtained for women, with the exception that the relation was not significantly negative in group C (beta(c) = -0.1, P = 0.4)., Conclusion: Plasma triglycerides and LDL-C are related in a parabolic fashion, not only in FCHL, but also in the general population and Type 2 DM. These findings aid our interpretation of typical dyslipidaemia and the effects of treatment that are frequently observed in hypertriglyceridaemic states.

Low serum HDL-cholesterol (HDL-C) is a major risk factor for coronary artery disease. We performed targeted genotyping of a 12.4 Mb linked region on 16q to test for association with low HDL-C by using a regional-tag SNP strategy. We identified one SNP, rs2548861, in the WW-domain-containing oxidoreductase (WWOX) gene with region-wide significance for low HDL-C in dyslipidemic families of Mexican and European descent and in low-HDL-C cases and controls of European descent (p = 6.9 x 10(-7)). We extended our investigation to the population level by using two independent unascertained population-based Finnish cohorts, the cross-sectional METSIM cohort of 4,463 males and the prospective Young Finns cohort of 2,265 subjects. The combined analysis provided p = 4 x 10(-4) to 2 x 10(-5). Importantly, in the prospective cohort, we observed a significant longitudinal association of rs2548861 with HDL-C levels obtained at four different time points over 21 years (p = 0.003), and the T risk allele explained 1.5% of the variance in HDL-C levels. The rs2548861 resides in a highly conserved region in intron 8 of WWOX. Results from our in vitro reporter assay and electrophoretic mobility-shift assay demonstrate that this region functions as a cis-regulatory element whose associated rs2548861 SNP has a specific allelic effect and that the region forms an allele-specific DNA-nuclear-factor complex. In conclusion, analyses of 9,798 subjects show significant association between HDL-C and a WWOX variant with an allele-specific cis-regulatory function.

Type 2 diabetes shares substantial genetic and phenotypic overlap with familial combined hyperlipidemia. Upstream stimulatory factor 1 (USF1), a well-established susceptibility gene for familial combined hyperlipidemia, is postulated to be such a shared genetic determinant. We evaluated two established variants in familial combined hyperlipidemia (rs2073658 and rs3737787) for association with type 2 diabetes in two Dutch case-control samples (N=2011). The first case-control sample comprised 501 subjects with type 2 diabetes from the Breda cohort and 920 healthy blood bank donors of Dutch Caucasian origin. The second case-control sample included 211 subjects with type 2 diabetes, and 379 normoglycemic controls. SNP rs2073658 and SNP rs3737787 were in perfect linkage disequilibrium. In the first case-control sample, prevalence of the major allele was higher in patients than in controls (75% versus 71%, OR=1.25, p=0.018). A similar effect-size and -direction was observed in the second case-control sample (76% versus 72%, OR=1.22, p=0.16). A combined analysis strengthened the evidence for association (OR=1.23, p=0.006). Notably, the increased risk for type 2 diabetes could be ascribed to the major allele, and its high frequency translated to a substantial population attributable risk of 14.5%. In conclusion, the major allele of rs2073658 in the USF1 gene is associated with a modestly increased risk to develop type 2 diabetes in Dutch Caucasians, with considerable impact at the population level.

Objective: Stearoyl-CoA desaturase 1 (SCD1) is the rate-limiting enzyme involved in the synthesis of monounsaturated fatty acids, and in mice SCD1 activity is associated with plasma triglyceride levels. We used the fatty acid desaturation index (the plasma ratio of 18:1/18:0) as a marker of SCD1 activity to investigate the relationship of SCD1 to familial combined hyperlipidemia (FCHL)., Methods and Results: The fatty acid desaturation index was measured in 400 individuals from 18 extended FCHL pedigrees. FCHL-affected individuals exhibited increased SCD1 activity when compared to unrelated controls (P < 0.0001). The fatty acid desaturation index was found to be highly heritable (h(2) = 0.48, P = 2.2 x 10(-11)) in this study sample. QTL analysis in 346 sibling pairs from 18 FCHL families revealed suggestive linkage of the desaturation index to chromosomes 3p26.1 to 3p13 (z = 2.7, P = 0.003), containing the peroxisome proliferator-activated receptor gamma (PPARgamma) gene, and 20p11.21 to 20q13.32 (z = 1.7, P = 0.04), containing the hepatocyte nuclear factor 4, alpha (HNF4alpha) gene. A specific haplotype of HNF4alpha was found to be associated with the desaturation index in these FCHL families (P = 0.002)., Conclusions: Our results demonstrate that the fatty acid desaturation index is a highly heritable trait that is associated with the dyslipidemia observed in FCHL.

Background: Genetic dissection of complex diseases requires innovative approaches for identification of disease-predisposing genes. A well-known example of a human complex disease with a strong genetic component is Type 2 Diabetes Mellitus (T2DM)., Methods: We genotyped normal-glucose-tolerant subjects (NGT; n = 54), subjects with an impaired glucose metabolism (IGM; n = 111) and T2DM (n = 142) subjects, in an assay (designed by Roche Molecular Systems) for detection of 68 polymorphisms in 36 cardiovascular risk genes. Using the single-locus logistic regression and the so-called haplotype entropy, we explored the possibility that (1) common pathways underlie development of T2DM and cardiovascular disease -which would imply enrichment of cardiovascular risk polymorphisms in "pre-diabetic" (IGM) and diabetic (T2DM) populations- and (2) that gene-gene interactions are relevant for the effects of risk polymorphisms., Results: In single-locus analyses, we showed suggestive association with disturbed glucose metabolism (i.e. subjects who were either IGM or had T2DM), or with T2DM only. Moreover, in the haplotype entropy analysis, we identified a total of 14 pairs of polymorphisms (with a false discovery rate of 0.125) that may confer risk of disturbed glucose metabolism, or T2DM only, as members of interacting networks of genes. We substantiated gene-gene interactions by showing that these interacting networks can indeed identify potential "disease-predisposing allele-combinations"., Conclusion: Gene-gene interactions of cardiovascular risk polymorphisms can be detected in prediabetes and T2DM, supporting the hypothesis that common pathways may underlie development of T2DM and cardiovascular disease. Thus, a specific set of risk polymorphisms, when simultaneously present, increases the risk of disease and hence is indeed relevant in the transfer of risk.

FCHL (familial combined hyperlipidaemia) is a highly prevalent genetic lipid disorder that accounts for a substantial number of premature cardiovascular events. To date, FCHL has been complicated by the different lipid phenotypes that are present within one family and one individual patient over time. In the present study, we hypothesized that a parabolic relationship between plasma triacylglycerols (triglycerides) and LDL (low-density lipoprotein)-cholesterol can explain this so-called 'multiple-type hyperlipidaemia' in FCHL. Our hypothesis was tested in two well-documented FCHL cohorts [Maastricht (n=145) and Nijmegen (n=299)] that were followed over a 5-year interval. Three groups were constructed depending on plasma triacylglycerols: group A (individuals with both measurements below 1.5 mmol/l), group B (one measurement below and one measurement above 1.5 mmol/l) and group C (both measurement above 1.5 mmol/l). In both male, but not female, cohorts, a significant positive relationship between plasma triacylglycerols and LDL-cholesterol was observed in group A (P=0.02 for Maastricht cohort and P=0.001 for the Nijmegen cohort), a significant negative relationship in group C (P=0.01 for Maastricht cohort and P=0.02 for the Nijmegen cohort), and a relationship intermediate to group A and C in group B. In contrast, both apoB (apolipoprotein B) levels and the prevalence of cardiovascular disease were related with plasma triacylglycerols in a more linear fashion. In conclusion, a parabolic relationship between plasma triacylglycerols and LDL-cholesterol explains the 'multiple-type hyperlipidaemia' in FCHL. In addition, the linear relationship between triacylglycerols and both apoB levels and the prevalence of cardiovascular disease substantiate the use of apoB instead of LDL-cholesterol in the diagnosis of FCHL and the prediction of cardiovascular disease.

Background: Familial combined hyperlipidemia (FCHL) is a genetic form of dyslipidemia, which is characterized by an increased cardiovascular risk. The current study was conducted to investigate the relation of endothelial, inflammatory and fibrinolysis markers with the presence of hypertriglyceridemia and fatty liver in FCHL, in order to advance insight in their contribution to the cardiovascular risk profile., Materials and Methods: Key plasma markers of low-grade inflammation, endothelial dysfunction and fibrinolysis were measured in 38 hypertriglyceridemic FCHL patients and 38 age and sex-matched spouses. The presence of fatty liver was determined with ultrasound., Results: hsCRP, vWF, PAI-1, tPA and tPA/PAI-1 complex levels were significantly higher in hypertriglyceridemic FCHL patients compared to spouses (p<0.05). Subsequent analyses revealed that these increased levels were confined to FCHL patients with the fatty liver phenotype (n=25). Only PAI-1 and tPA levels were also elevated in the hypertriglyceridemic FCHL patients without fatty liver (n=13). Of interest, 11 hypertriglyceridemic non-FCHL patients with the E2/E2 genotype displayed significantly lower PAI-1 levels when compared to the overall FCHL population (p=0.001), implicating a role for apolipoprotein E in the relation of PAI-1 with plasma triglycerides., Conclusion: Markers of fibrinolysis were increased in all hypertriglyceridemic FCHL patients, whereas an increased state of endothelial dysfunction and inflammation was particularly observed in those hypertriglyceridemic FCHL patients who also have fatty liver. These results demonstrate the complex genesis of the unfavourable cardiovascular risk profile that is present in FCHL, and illustrate the potential risk of fatty liver above, and beyond hypertriglyceridemia per se.

Objective: To evaluate a novel quantitative magnetic resonance (QMR) methodology (EchoMRI-AH, Echo Medical Systems) for measurement of whole-body fat and lean mass in humans., Methods and Procedures: We have studied (i) the in vitro accuracy and precision by measuring 18 kg Canola oil with and without 9 kg water (ii) the accuracy and precision of measures of simulated fat mass changes in human subjects (n = 10) and (iii) QMR fat and lean mass measurements compared to those obtained using the established 4-compartment (4-C) model method (n = 30)., Results: (i) QMR represented 18 kg of oil at 40 degrees C as 17.1 kg fat and 1 kg lean while at 30 degrees C 15.8 kg fat and 4.7 kg lean were reported. The s.d. of repeated estimates was 0.13 kg for fat and 0.23 kg for lean mass. Adding 9 kg of water reduced the fat estimates, increased misrepresentation of fat as lean, and degraded the precision. (ii) the simulated change in the fat mass of human volunteers was accurately represented, independently of added water. (iii) compared to the 4-C model, QMR underestimated fat and over-estimated lean mass. The extent of difference increased with body mass. The s.d. of repeated measurements increased with adiposity, from 0.25 kg (fat) and 0.51 kg (lean) with BMI <25 kg/m(2) to 0.43 kg and 0.81 kg respectively with BMI >30 kg/m(2)., Discussion: EchoMRI-AH prototype showed shortcomings in absolute accuracy and specificity of fat mass measures, but detected simulated body composition change accurately and with precision roughly three times better than current best measures. This methodology should reduce the study duration and cohort number needed to evaluate anti-obesity interventions.

Introduction: Familial combined hyperlipidemia (FCHL), an entity with many features of the metabolic syndrome, is characterized by changes in cholesterol and triglyceride phenotype over time. This study was conducted to investigate the relation of alanineaminotransferase (ALT) levels, used as a surrogate for the amount of hepatic fat, with the switch in triglyceride phenotype and the increased susceptibility to develop hypertriglyceridemia in FCHL., Methods: Body mass index, waist circumference, plasma triglycerides, insulin and ALT levels were measured in 145 FCHL family members and 54 spouses at baseline and after a five-year follow-up., Results: A switch from normotriglyceridemia to hypertriglyceridemia or vice versa, as observed in 22 of 145 FCHL family members, was associated with changes in plasma ALT levels (p=0.001), but not with insulin levels or waist circumference. In five-year follow-up, an intra-individual relation was observed between waist circumference and both plasma triglycerides, insulin and ALT levels. For each waist circumference FCHLpatients, but not their normolipidemic relatives, exhibited higher triglyceride and insulin levels than spouses (p<0.001). Remarkably, both FCHL patients and the normolipidemic relatives showed higher ALT levels for each waist circumference as compared to spouses(p<0.001 for FCHL patients, p=0.035 for normolipidemic relatives)., Conclusion: The present study shows that the longitudinal relation abdominal obesity-ALT is more specific for all FCHL family members, i.e. patients and their normolipidemic relatives, than the relation abdominal obesity-triglycerides. Additionally,the association of ALT with the switch in triglyceride phenotype suggests a central role of the liver in the pathogenesis of FCHL.

Objective: Familial combined hyperlipidemia (FCHL) characterized by high serum total cholesterol and/or triglycerides (TGs) is a common dyslipidemia predisposing to coronary artery disease (CAD). Recently, the upstream transcription factor 1 (USF1) was linked and associated with FCHL and TGs in Finnish FCHL families. Here we examined the previously associated rs3737787 SNP in extended Dutch FCHL families (n=532) and in a cohort of US subjects who underwent diagnostic coronary angiography (n=1533)., Methods and Results: In males of the Dutch FCHL families, we observed significant sex-dependent associations between the common allele of rs3737787 and FCHL, TGs, and related metabolic traits (P=0.02 to 0.006). In the U.S. Whites, sex-dependent associations with TGs and related metabolic traits were observed for the common allele of rs3737787 in males (P=0.04 to 0.02) and rare allele in females (P=0.05 to 0.002). This intriguing relationship was further supported by the highly significant genotype x sex interactions observed for TGs in the Dutch and TGs and body mass index (BMI) in U.S. White subjects with CAD (P=0.0005 to 0.00004)., Conclusions: These data show that USF1 influences several cardiovascular risk factors in a sex-dependent manner in Dutch FCHL families and U.S. Whites with CAD. A significant interaction between sex and genotype was shown to affect TGs and BMI.

The present study was conducted to investigate whether the fatty liver phenotype could be helpful in the identification of subgroups with distinct metabolic properties and lipid profiles within familial combined hyperlipidemia (FCHL). One hundred eighty-five FCHL family members participated in the current study; 38 subjects were found to be hypertriglyceridemic, of whom 66% showed evidence of fatty liver as measured with ultrasound. A detailed comparison between the hypertriglyceridemic FCHL subjects with (n = 25) and without (n = 13) fatty liver revealed that, despite very similar plasma triglyceride levels (3.5 vs 3.2 mmol/L in subjects with and without fatty liver, respectively), the fatty liver subgroup presented with significantly higher body mass index, visceral adipose tissue (ultrasound), insulin, and alanine aminotransferase levels. Moreover, very low-density lipoprotein (VLDL) subclass analysis showed that the VLDL2 fraction of the fatty liver subgroup contained significantly less cholesterol and triglycerides (P = .02 for both parameters), which was likely explained by a decreased VLDL2 particle number because VLDL2 apolipoprotein B levels tended to be lower (P = .08). These data indicate that hypertriglyceridemic FCHL subjects may belong to metabolically distinct subgroups and suggest that a refinement of the hypertriglyceridemic FCHL phenotype by adding information on fatty liver will eventually facilitate the elucidation of its complex genetic background.

Context: Activating transcription factor 6 (ATF6) is critical for initiation and full activation of the unfolded protein response. An association between genetic variation in ATF6 and type 2 diabetes (DM2) was recently reported in Pima Indians., Objectives: To investigate the broader significance of this association for DM2, replication studies in distinct ethic populations are required. We investigated ATF6 for its association with DM2 in Dutch Caucasians., Design/setting: A genetic association study was conducted at an academic research laboratory., Study Participants: Two independent Dutch cohorts were studied. Cohort 1 (n = 154) was used to evaluate genetic variation in the ATF6 gene in relation to glucose homeostasis in the general population. Cohort 2 (n = 798) consisted of patients with DM2, impaired glucose tolerance, impaired fasting glucose, and normoglycemic control subjects, and was used to investigate ATF6 polymorphisms for their contribution to disturbed glucose homeostasis and DM2., Main Outcome Measures: There were 16 tag single nucleotide polymorphisms genotyped in all subjects of both cohorts. Those single nucleotide polymorphisms included three nonsynonymous coding variants and captured all common allelic variation of ATF6., Results: Our data show that common ATF6 variants are associated with elevated glucose levels in the general population (cohort 1, P = 0.005-0.05). Furthermore, the majority of these variants, and haplotypes thereof, were significantly associated with impaired fasting glucose, impaired glucose tolerance, and DM2 (cohort 2, P = 0.006-0.05). Associated variants differ from those identified in Pima Indians., Conclusions: Our results strengthen the evidence that one or more variants in ATF6 are associated with disturbed glucose homeostasis and DM2.

Aims: Thioredoxin interacting protein (TXNIP) is an attractive candidate gene for diabetes or diabetic dyslipidaemia, since TXNIP is the strongest glucose-responsive gene in pancreatic B-cells, TXNIP deficiency in a mouse model is associated with hyperlipidaemia and TXNIP is located in the 1q21-1q23 chromosomal Type 2 diabetes mellitus (DM) locus. We set out to investigate whether metabolic effects of TXNIP that were previously reported in a murine model are also relevant in human Type 2 DM., Methods: The frequency distribution of a 3' UTR single nucleotide polymorphism (SNP) in TXNIP was investigated in subjects with normal glucose tolerance (NGT; n = 379), impaired glucose tolerance (IGT; n = 228) and Type 2 DM (n = 230). Metabolic data were used to determine the effect of this SNP on parameters associated with lipid and glucose metabolism., Results: The frequency of the TXNIP variation did not differ between groups, but within the group of diabetic subjects, carriers of the TXNIP-T variant had 1.6-fold higher triglyceride concentrations (P = 0.015; n = 136) and a 5.5-mmHg higher diastolic blood pressure (P = 0.02; n = 212) than homozygous carriers of the common C-allele, whereas in non-diabetic subjects fasting glucose was 0.26 mmol/l lower (P = 0.002; n = 478) in carriers of the T-allele. Moreover, a significant interaction between plasma glucose concentrations and TXNIP polymorphism on plasma triglycerides was observed (P = 0.012; n = 544)., Conclusion: This is the first report to implicate TXNIP in a human disorder of energy metabolism, Type 2 diabetes. The effect of TXNIP on triglycerides is influenced by plasma glucose concentrations, suggesting that the biological relevance of TXNIP variations may be particularly relevant in recurrent episodes of hyperglycaemia.

Overproduction of VLDL (very-low-density lipoprotein) particles is an important cause of FCHL (familial combined hyperlipidaemia). It has been shown recently that VLDL production is driven by the amount of hepatic fat. The present study was conducted to determine the prevalence of fatty liver in relation to the different fat compartments and lipid parameters in FCHL. A total of 68 FCHL patients, 110 normolipidaemic relatives and 66 spouses underwent ultrasound of the abdominal region to estimate the amount of subcutaneous, visceral and hepatic fat. Skinfold callipers were used to measure subcutaneous fat of the biceps, triceps, subscapular and supra-iliacal regions. Fatty liver was observed in 18% of the spouses, 25% of the normolipidaemic relatives and 49% of the FCHL patients. After adjustment for age, gender and body mass index, the prevalence of fatty liver was significantly higher in FCHL patients compared with spouses [OR (odds ratio), 3.1; P=0.03], and also in the normolipidaemic relatives compared with spouses (OR, 4.0; P=0.02), whereas no differences were observed between FCHL patients and normolipidaemic relatives (OR, 0.8; P=0.58). In the normolipidaemic relatives and FCHL patients combined, both visceral fat mass and subcutaneous abdominal fat were independent predictors of fatty liver (P<0.001 for both fat compartments; FCHL status corrected). Of interest, fatty liver stages were correlated with both VLDL-apoB (apolipoprotein B) and VLDL-triacylglycerols (triglycerides) in a representative subset (n=69) of patients and relatives (r(2)=0.12, P=0.006; and r(2)=0.18, P=0.001 respectively). These results show that fatty liver is a central aspect of FCHL, i.e. patients and normolipidaemic relatives. Both visceral and subcutaneous adiposity contribute to its 3-4-fold higher risk in FCHL.

VLDL overproduction, a process that is driven by an excess amount of hepatic fat, is a well-documented feature of familial combined hyperlipidemia (FCHL). The aims of this study were to investigate whether fatty liver, measured with ultrasound and as plasma alanine aminotransferase (ALT) levels, develops against a genetic background in FCHL and to identify chromosomal loci that are linked to these traits. In total, 157 FCHL family members and 20 spouses participated in this study. Radiological evidence of fatty liver was more prevalent not only in FCHL probands (40%) but also in their relatives (35%) compared with spouses (15%) (P < 0.05). Heritability calculations revealed that 20-36% of the variability in ALT levels could be attributed to genetic factors. Nonparametric quantitative trait locus (QTL) analysis revealed three significant (P < 0.001) loci with either the ultrasound or the ALT trait in the male sample: 1q42.3, 7p12-21, and 22p13-q11; none was found in the female sample or the entire group. Of these QTLs, the 7p region was consistent over time, because reanalysis with ALT levels that were determined during a visit 5 years earlier yielded similar results. This study shows that fatty liver is a heritable aspect of FCHL. Replication of particularly the 7p region is awaited.

Aims/hypothesis: The aim of this study was to investigate whether lifestyle intervention-induced changes in serum fatty acid profile of cholesteryl esters and estimated desaturase activities are related to improvements in insulin sensitivity in subjects at risk of type 2 diabetes., Materials and Methods: In the Study on Lifestyle Intervention and Impaired Glucose Tolerance Maastricht (SLIM), 97 men and women with IGT were randomised to a combined diet and exercise programme (47 intervention) or a control group (50 control subjects). At baseline and after 1 year the following assessments were made: an OGTT, an exercise test to determine maximal aerobic capacity, anthropometry, and analysis of the serum fatty acid profile of cholesteryl esters., Results: The lifestyle programme was effective in reducing the intake of total and saturated fat, increasing physical activity, reducing obesity and improving insulin sensitivity and glucose tolerance. Regression analysis of the total population showed that an increase in the C20:4 n-6/C20:3 n-6 ratio (estimated Delta5-desaturase activity) and reductions in the C18:3 n-6/C18:2 n-6 ratio (estimated Delta6-desaturase activity) and the C16:1 n-7/C16:0 ratio (estimated Delta9-desaturase activity or stearoyl-CoA desaturase-1) were significantly associated with a decrease in homeostasis model assessment for insulin resistance. After adjustment for lifestyle changes (change in percentage body fat, aerobic capacity and saturated fat intake), these associations were partly reduced, but remained statistically significant., Conclusions/interpretation: Lifestyle-induced changes in fatty acid profile of cholesteryl esters and desaturase activities were independently related to changes in insulin sensitivity in subjects at risk of type 2 diabetes.

Aims: The membrane-bound fatty acid transporter CD36/FAT may play a role in disturbed fatty acid handling as observed in the metabolic syndrome and Type 2 diabetes mellitus (T2DM). Genetic variation in the CD36 gene may contribute to the aetiology of diabetes., Methods: A population-based cohort in the Netherlands [age > 40 years and body mass index (BMI) > 25 kg/m2] of 675 subjects was phenotyped with respect to glucose metabolism with an oral glucose tolerance test and was genotyped for a known 478C-->T substitution and a C/T snp in the upstream promoter region (rs1527479) in the CD36 gene., Results: T2DM was more prevalent in the TT genotype than in the CC genotype. This was most pronounced in women and in subjects with a high BMI (BMI > 27 kg/m2). In addition, within the group of diabetic patients, the TT genotype was commoner in subjects with increased homeostasis model assessment (HOMA) index for insulin resistance. The 478C-->T substitution, previously found in the Japanese population, was not found in our caucasian population., Conclusions: This is the first study to show a direct association of a CD36 snp with T2DM. Moreover, within the diabetic subjects, this CD36 snp was associated with insulin resistance (HOMA index).

Familial combined hyperlipidemia (FCHL) shows many features of the metabolic syndrome. The strong genetic component makes it an excellent model to study the genetic background of metabolic syndrome and insulin resistance. Adipose tissue is believed to contribute to, or even underlie, the FCHL phenotype and is an interesting target tissue for gene expression studies. However, interpretation of adipose tissue gene expression experiments is complex since expression differences cannot only arise as a direct consequence of a genetic trait, but may also reflect an adaptation to metabolic influences at the cellular level. In the present study, we measured gene expression levels in cultured primary human preadipocytes from FCHL and control subjects. Since isolated preadipocytes were allowed to replicate for weeks under standardized conditions, the contribution of previous metabolic influences is rather small whereas genetic defects are preserved and expressed in vitro. The main finding was up-regulation of CD36/FAT in FCHL preadipocytes, confirmed in two independent groups of subjects, and a concomitant increase in CD36/FAT-mediated fatty acid uptake. CD36/FAT overexpression has previously been shown to be associated with other insulin-resistant states. The present data suggest that CD36/FAT overexpression in FCHL occurs very early in adipocyte differentiation and may be of genetic origin.

Aims: To evaluate the relation between common variants in the ATP-sensitive K+ channel genes and glucose intolerance., Methods: We conducted a meta-analysis of reported association studies in Caucasian populations for common variants in the ABCC8 (exons 16 and 18) and the KCNJ11 (E23K) gene and examined sources of heterogeneity in the results. The meta-analysis was based on 7768-10216 subjects (depending on the gene variant), and included two new population-based studies in the Netherlands with 725 cases and 742 controls., Results: For the KCNJ11 variant, the summary odds ratio (OR) for glucose intolerance was 1.12 (1.01-1.23, P=0.03) for the EK genotype and 1.44 (1.17-1.78, P=0.0007) for the KK genotype, as compared with the EE genotype. For the ABCC8 exon 16 variant, the OR was 1.06 (0.94-1.19, P=0.34) for ct and 0.93 (0.71-1.20, P=0.56) for tt, as compared with the cc genotype. For ABCC8 exon 18, the OR was 1.20 (0.97-1.49, P=0.10) for CT/TT, as compared with the CC genotype. Studies of the ABCC8 variants that were published first or had smaller sample sizes (for the exon 18 variant) showed stronger associations, which may indicate publication bias. For the ABCC8 exon 18 and the KCNJ11 variant, associations were stronger for studies of clinical diabetes than newly detected glucose intolerance. The population attributable risk for clinical Type 2 diabetes was 6.2% for the KCNJ11 KK genotype and 10.1% for the KCNJ11 EK and KK genotype combined., Conclusions: The common KCNJ11 E23K gene variant, but not the ABCC8 exon 16 or exon 18 variant, was consistently associated with Type 2 diabetes.

Objective: To investigate the role of abdominal and body obesity on the prevalence of hyperlipidemia, in particular, hypertriglyceridemia, hypercholesterolemia, and high apolipoprotein B levels, in familial combined hyperlipidemia (FCHL) relatives and their spouses., Research Methods and Procedures: In FCHL relatives (n = 618) and spouses (n = 297), prevalence data of hyperlipidemia and high apolipoprotein B levels and their age and gender-corrected odds ratios (ORs) were calculated for sex-adjusted categories of waist-to-hip ratio (WHR), waist circumference, and BMI., Results: Increments of BMI, waist circumference, and WHR increased the frequency of hyperlipidemia. In the whole study population (relatives and spouses combined), frequency of hypertriglyceridemia showed a significant interaction only between WHR categories and FCHL. This was studied further after stratification of relatives by multivariable logistic regression analyses corrected for age and gender. Predominant expression of hypertriglyceridemia was observed with higher categories of WHR in FCHL relatives (prevalence up to 57.6%, OR 8.48 in highest vs. lowest WHR category, p < 0.001) but not in spouses (up to 32.9%, OR 1.05 in highest vs. lowest WHR category, not significant)., Discussion: Both in spouses and FCHL relatives, increments in BMI and waist circumference increased the prevalence of hyperlipidemia. Specifically, in FCHL relatives, WHR was the most informative determinant of the expression of hyperlipidemia, in particular, hypertriglyceridemia. The data indicate that FCHL develops against a background of abdominal obesity.

Objectives: The genetic background of familial combined hyperlipidemia (FCHL) is currently unclear. We propose transcriptional profiling as a complementary tool for its understanding. Two hypotheses were tested: the existence of a disease-specific modification of gene expression in FCHL and the detectability of such a transcriptional profile in blood derived cell lines., Methods and Results: We established lymphoblastic cell lines from FCHL patients and controls. The cells were cultured in fixed conditions and their basal expression profile was compared using microarrays; 166 genes were differentially expressed in FCHL-derived cell lines compared with controls, with enrichment in metabolism-related genes. Of note was the upregulation of EGR-1, previously found to be upregulated in the adipose tissue of FCHL patients, the upregulation of DCHR-7, the downregulation of LYPLA2, and the differential expression of several genes previously unrelated to FCHL. A cluster of potential EGR-1-regulated transcripts was also differentially expressed in FCHL cells., Conclusions: Our data indicate that in FCHL, a disease-specific transcription profile is detectable in immortalized cell lines easily obtained from peripheral blood and provide complementary information to classical genetic approaches to FCHL and/or the metabolic syndrome.

Background: Familial combined hyperlipidemia (FCHL) is characterized by a varied expression of hypertriglyceridemia and hypercholesterolemia within a family, and a high risk of premature coronary artery disease. The present study evaluated a number of potential prothrombotic markers in familial combined hyperlipidemia, and studied their relationship to the hypercholesterolemic (Fredrickson type IIa) and hypertriglyceridemic (IIb and IV) phenotypes., Methods and Results: Selected prothrombotic markers were studied in 68 subjects: 34 hyperlipidemic subjects with familial combined hyperlipidemia and 34 controls. FCHL patients exhibited significantly higher Thrombin-Antithrombin complex (TAT), activated coagulation factor XII (F XIIa), von Willebrand Factor (vWF), Plasminogen Activator Inhibitor-1 (PAI-1) and tissue derived Plasminogen Activator (t-PA) values in comparison to controls. Within the subgroup of familial combined hyperlipidemia subjects, elevated PAI-1 activity and soluble Thrombomodulin levels were particularly associated with features of the metabolic syndrome, including hyperinsulinemia, hypertriglyceridemia and predominance of small dense low density lipoprotein (LDL)., Conclusions: A general pattern of activated blood coagulation and endothelial activation is present in all hyperlipidemic subjects studied, independent of metabolic phenotype. In those familial combined hyperlipidemia subjects with features of the metabolic syndrome, impaired fibrinolysis can provide an additional cardiovascular risk factor., (Copyright 2004 Elsevier Ireland Ltd)

The inbred HcB19 mouse strain expresses a truncated form of thioredoxin interacting protein and is phenotypically characterized by fatty liver and elevated plasma triglycerides and VLDL. Recently, these mice have been proposed as an animal model for familial combined hyperlipidemia. The aim of the present study was identification of hepatic proteins specifically associated with the presence of fatty liver. Eighteen differential proteins were detected in whole-liver homogenate from HcB19, or the parental strain C3H, using 2D electrophoresis, and 11 of those were successfully identified by mass spectrometry. Five of the identified differential proteins were mitochondrial, two peroxisomal, two cytosolic, and two secretory. Four differential proteins were novel in the fatty liver proteome [i.e., aconitase, succinate dehydrogenase, propionyl CoA carboxylase alpha chain (PCCA), and 3-hydroxyanthranilate 3,4 dioxygenase (3HAAO)]. Of these, PCCA and 3HAAO are of particular interest because of their known functions in nicotinic acid metabolism (3HAAO) and ketogenesis (PCCA). We have newly identified several differential proteins in the hepatic proteome of mice with fatty liver, including PCCA and 3HAAO, and confirmed differential expression of previously reported proteins. These individual proteins, PCCA and 3HAAO, can be important in development of fatty liver or in the expression of hyperlipidemia.

The APOLIPOPROTEIN (APO)A1/C3/A4/A5 gene cluster on chromosome 11 has been hypothesized to be a modifier of plasma triglycerides in FCH. In the present study, we extended previous association analyses of the gene cluster to include APOA5, a newly discovered member of the cluster. Eight SNPs across the APOA1/C3/A4/A5 gene region were analyzed in 78 FCH probands and their normolipidemic spouses as well as in 27 Dutch FCH families. Of the individual SNPs tested in the case-control panel, the strongest evidence of association was obtained with SNPs in APOA1 (P=0.001) and APOA5 (P=0.001). A single haplotype defined by a missense mutation in APOA5 was enriched 3-fold in FCH probands when compared with the normolipidemic spouses (P=0.001) and a second haplotype was significantly enriched in the spouses (P=0.001). Family-based tests also indicated significant association of triglyceride levels and LDL particle size with the investigated SNPs of APOC3 and APOA5. These findings suggest that genetic variation in the APOA1/C3/A4/A5 gene cluster acts as a modifier of plasma triglyceride levels and LDL particle size within FCH families and furthermore indicate that a number of haplotypes may contribute to FCH.

Objective: The present study addresses the presence of distinct metabolic phenotypes in familial combined hyperlipidemia (FCHL) in relation to small dense low-density lipoprotein (sd LDL) and very low-density lipoprotein (VLDL) subclasses., Methods and Results: Hyperlipidemic FCHL relatives (n=72) were analyzed for LDL size by gradient gel electrophoresis. Pattern B LDL (sd LDL, particle size <258 A) and pattern A LDL (buoyant LDL, particle size > or =258 A) were defined. Analyses showed bimodal distribution of LDL size associated with distinct phenotypes. Subjects with predominantly large, buoyant LDL showed a hypercholesterolemic phenotype and the highest apo B levels. Subjects with predominantly sd LDL showed a hypertriglyceridemic, low high-density lipoprotein (HDL) cholesterol phenotype, with moderately elevated apoB, total cholesterol level, and LDL cholesterol level. Subjects with both buoyant LDL and sd LDL (pattern AB, n=7) showed an intermediate phenotype, with high normal plasma triglycerides. VLDL subfraction analysis showed that the sd LDL phenotype was associated with a 10-times higher number of VLDL1 particles of relatively lower apo AI and apo E content, as well as smaller VLDL2 particles, in combination with increased plasma insulin concentration in comparison to pattern A., Conclusions: The present observations underscore the importance of the VLDL triglyceride metabolic pathway in FCHL as an important determinant of the phenotypic heterogeneity of the disorder.

Background: The use of an oral glucose tolerance test (OGTT) has been recommended to diagnose type 2 diabetes, but an OGTT with venous blood sampling may not be feasible in the screening phase preceding large epidemiological studies. We have conducted a population-based screening in 2715 men and women and evaluated the diagnostic validity of capillary plasma glucose concentration measurements versus venous plasma glucose concentration measurements in a subset of 350 subjects., Methods: During a single OGTT, glucose concentrations were measured in venous plasma as well as in capillary plasma., Results: Based on the 1999 WHO criteria for venous glucose concentrations, the study population (n=350) yielded 97 subjects with type 2 diabetes mellitus, 77 subjects with impaired glucose tolerance and 176 subjects with normal glucose tolerance. Sensitivity and specificity to diagnose type 2 diabetes mellitus by capillary plasma were 84% and 98%, respectively. Consistent classification by either venous or capillary plasma glucose measurements was 78% (kappa=0.65, p<0.001)., Conclusion: Capillary glucose measurements are suitable for use in epidemiological studies to diagnose and detect type 2 diabetes and normal glucose tolerance. Use of capillary measurements can result in cost-effective inclusion schemes in epidemiological studies.

The role of endogenous estrogens and androgens and their potential interaction in atherosclerosis is not well understood. Therefore, we investigated the effects of natural menopause and endogenous sex steroids on triglycerides (TG), a major risk factor for cardiovascular disease in women. Fasting lipid and lipoprotein concentrations, postheparin lipase activities, kinetic indicators of triglyceride lipolysis, and various hormone levels, including dehydroepiandrostenedione-sulfate (DHEA-S), (bioavailable) testosterone, and androstenedione, were determined in 18 premenopausal and 18 postmenopausal women, matched for age and body composition. Fasting plasma TG were 0.69 +/- 0.29 mmol/L in postmenopausal women and 0.73 +/- 0.33 mmol/L in premenopausal women (difference not significant [NS]). Approximately 30% of all plasma TG were present in the very-low-density lipoproteins (VLDLs) in both groups. No differences were found between groups in plasma lipolytic potential of TG-rich lipoproteins. Univariate analysis revealed that VLDL-TG concentrations were strongly related to insulin (r = 0.84, P =.0001) and androstenedione (r = 0.65, P =.004) in postmenopausal women. Multivariate analysis of potential determinants of VLDL-TG showed that insulin, androstenedione, and bioavailable testosterone were independent variables, explaining 87% of the variability (r = 0.93, P =.0001) in postmenopausal women. In contrast, in premenopausal women, the only identified predictor of fasting VLDL-TG in univariate and multivariate analysis was insulin (r = 0.72, P =.001). Our results show that the association of androgens with TG varied depending on androgen concentrations, the relative androgenic potential, and most importantly on hormonal milieu. Endogenous androgens were only related to plasma VLDL-TG in the estrogen-deficient state.

Objective: Changing dietary and physical activity habits has the potential to postpone or prevent the development of type 2 diabetes. However, it needs to be assessed whether moderate interventions, in agreement with current guidelines for the general population, are effective. We evaluated the impact of a 2-year combined diet and physical activity intervention program on glucose tolerance in Dutch subjects at increased risk for developing diabetes., Research Methods and Procedures: Subjects with glucose intolerance were randomly assigned to either the lifestyle intervention group (INT) or control group (CON). The INT received regular dietary advice and was stimulated to increase their physical activity. The CON received a brief leaflet about healthy diet and increased physical activity. Primary outcome measure was the change in glucose tolerance., Results: In total, 88 subjects completed 2 years of intervention (40 subjects in the INT, 48 subjects in the CON, mean BMI 29.4 kg/m2). Subjects in the INT reduced their body weight, waist circumference, and (saturated) fat intake and improved their aerobic capacity. Two-hour plasma glucose concentration declined from 8.7 to 8.0 mM in the INT and rose from 8.6 to 9.4 mM in the CON (p < 0.01). Subjects adherent to both the diet and exercise intervention showed the largest reduction in 2-hour glucose levels., Discussion: Our results showed that a lifestyle intervention program according to general recommendations improves glucose tolerance, even in a less obese and more physical active population. Furthermore, our results underscore the importance of combining diet and physical activity to improve glucose tolerance and insulin resistance.

Familial combined hyperlipidemia (FCHL) is a common genetic lipid disorder characterized by premature coronary artery disease, dyslipidemia, insulin resistance, and impaired adipose tissue free fatty acid (FFA) metabolism. Increased adipose tissue FFA flux towards the liver may, in part, contribute to reduced insulin sensitivity and hyperlipidemia in FCHL. It was the objective of the present study to evaluate the contribution of the peroxisome proliferator-activated receptor gamma (PPARgamma) gene to FCHL traits related to adipocyte lipid metabolism, dyslipidemia, and insulin resistance. In a case-control panel consisting of 79 FCHL probands and 124 spouse controls, polymorphic marker D3S1259 and three intragenic PPARgamma variants, i.e., 161C > T, Pro12Ala, and Pro115Gln, were studied. The Pro115Gln variant was not found in any of the subjects. Allele frequencies of the 161C > T, Pro12Ala variants, and D3S1259 did not differ significantly between FCHL probands and spouses. In FCHL probands, individuals heterozygous or homozygous for the 161T allele had lower plasma concentrations of FFA (P < 0.05) and glycerol (P < 0.01). No significant associations were found in spouses. These findings identify PPARgamma as a quantitative trait locus for FFA and glycerol, against a background of insulin resistance for adipose tissue lipid metabolism, and therefore as a modifier gene in FCHL.

Aims/hypothesis: Skeletal muscle of pre-diabetic patients is characterised by a diminished capacity to handle fatty acids. A diminished content of several enzymes involved in fatty-acid transport and oxidation have been suggested to underlie these defects. The aim of this study was to investigate whether the combination of dietary advice, increased physical activity and weight loss improves lipid metabolic gene and protein expression in skeletal muscle of subjects with impaired glucose tolerance., Methods: Before and after 1 year of a lifestyle-intervention programme, expression of several genes and proteins involved in lipid metabolism were measured in vastus lateralis muscle biopsies from subjects in the intervention ( n=7) and control group ( n=6)., Results: After 1 year the intervention group had an improved glycaemic control and reduced body fat compared to the control group. Significant differences were observed for acetyl CoA-carboxylase 2 and uncoupling protein 2 expression (ACC2: -16.8+/-12.4% vs +51.5+/-32.3% for the intervention and control group respectively; p<0.05) (UCP2: -26.9+/-10.3% vs +10.5+/-6.2% for the intervention and control group respectively; p<0.05). Change in 3-hydroxyacyl-CoA dehydrogenase protein content tended to be different between groups (+3.2+/-1.1 vs -0.9+/-1.9 U/mg.ww for the intervention and control group, p=0.07)., Conclusions/interpretation: Lifestyle changes leading to an improved glycaemic control and reduced adiposity, resulted in a down-regulation of ACC-2 and UCP2 expression and in an increase in HAD protein content, reflecting a better capacity to utilise fatty acids.

The study on lifestyle-intervention and impaired glucose tolerance Maastricht (SLIM) is a 3 years randomised clinical trial designed to evaluate the effect of a combined diet and physical activity intervention program on glucose tolerance in a Dutch population at increased risk for developing type 2 diabetes. Here the design of the lifestyle-intervention study is described and results are presented from the preliminary population screening, conducted between March 1999 and June 2000. In total, 2,820 subjects with an increased risk of having disturbances in glucose homeostasis (i.e. age >40 years and BMI>25 kg/m(2) or a family history of diabetes) underwent a first oral glucose tolerance test (OGTT). Abnormal glucose homeostasis was detected in 826 subjects (30.4%): 226 type 2 diabetes (type 2DM, 8.3%), 215 impaired fasting glucose (IFG, 7.9%) and 385 impaired glucose tolerance (IGT, 14.2%). Both increasing age and BMI were strongly related to the prevalence of IGT and diabetes. After a second OGTT, 114 subjects with glucose intolerance and in otherwise good health were eligible for participation in the intervention study (SLIM). The high prevalence of disturbances in glucose homeostasis observed in the preliminary screening underscore the importance of early (lifestyle) interventions in those at risk for developing diabetes. SLIM will address this topic in the Dutch population.

Apolipoprotein A-II (apoA-II) is a major protein on high-density lipoprotein (HDL) particles, and in mice, its levels are associated with triglyceride and glucose metabolism. In particular, transgenic mice overexpressing apoA-II exhibit hypertriglyceridemia, increased body fat, and insulin resistance, whereas apoA-II-null mice have decreased triglycerides and increased insulin sensitivity. Given the phenotypic overlap between familial combined hyperlipidemia (FCH) and apoA-II transgenic mice, we investigated the relationship of apoA-II to this disorder. Despite having lower HDL-cholesterol (HDL-C), FCH subjects had higher apoA-II levels compared with unaffected relatives (P<0.00016). Triglyceride and HDL-C levels were significant predictors of apoA-II, demonstrating that apoA-II variation is associated with several FCH-related traits. After adjustment for multiple covariates, there was evidence for the heritability of apoA-II levels (h2=0.15; P<0.02) in this sample. A genome scan for apoA-II levels identified significant evidence (LOD=3.1) for linkage to a locus on chromosome 1q41, coincident with a suggestive linkage for triglycerides (LOD score=1.4). Thus, this locus may have pleiotropic effects on apoA-II and FCH traits. Our results demonstrate that apoA-II is biochemically and genetically associated with FCH and may serve as a useful marker for understanding the mechanism by which FCH develops.

Several genomewide screens have been performed to identify novel loci predisposing to unfavorable serum lipid levels and coronary heart disease (CHD). We hypothesized that the accumulating data of these screens in different study populations could be combined to verify which of the identified loci truly harbor susceptibility genes. The power of this strategy has recently been demonstrated with other complex diseases, such as inflammatory bowel disease and asthma. We assessed the largely unknown genetic background of CHD by investigating the most common dyslipidemia predisposing to CHD, familial combined hyperlipidemia (FCHL), affecting 1%-2% of Western populations and 10%-20% of families with premature CHD. To be able to perform a combined data analysis, we unified the diagnostic criteria for FCHL and its component traits and combined the data from two genomewide scans performed in two populations, the Finns and the Dutch. As a result of our pooled data analysis, we identified three chromosomal regions, on chromosomes 2p25.1, 9p23, and 16q24.1, exceeding the statistical significance level of a LOD score >2.0. The 2p25.1 region was detected for the FCHL trait, and the 9p23 and 16q24.1 regions were detected for the low high-density lipoprotein cholesterol (HDL-C) trait. In addition, the previously recognized 1q21 region also obtained additional support in the other study sample, when the triglyceride trait was used. Analysis of the 16q24.1 region resulted in a statistically significant LOD score of 3.6 when the data from Finnish families with low HDL-C were included in the analysis. To search for the underlying gene in the 16q24.1 region, we investigated a novel functional and positional candidate gene, helix/forkhead transcription factor (FOXC2), by sequencing and by genotyping of two single-nucleotide polymorphisms in the families.

Aims: Important risk factors for the progression from impaired glucose tolerance to type II diabetes mellitus are obesity, diet and physical inactivity. The aim of this study is to evaluate the effect of a lifestyle-intervention programme on glucose tolerance in Dutch subjects with impaired glucose tolerance (IGT)., Methods: A total of 102 subjects were studied, randomised into two groups. Subjects in the intervention group received regular dietary advice, and were stimulated to lose weight and to increase their physical activity. The control group received only brief information about the beneficial effects of a healthy diet and increased physical activity. Before and after the first year, glucose tolerance was measured and several other measurements were done., Results: Body weight loss after 1 y was higher in the intervention group. The 2-h blood glucose concentration decreased 0.8+/-0.3 mmol/l in the intervention group and increased 0.2+/-0.3 mmol/l in the control group (P<0.05). Body weight loss and increased physical fitness were the most important determinants of improved glucose tolerance and insulin sensitivity., Conclusion: A lifestyle-intervention programme according to general recommendations is effective and induces beneficial changes in lifestyle, which improve glucose tolerance in subjects with IGT. Body weight loss and increased physical fitness were the most important determinants of improved glucose tolerance and insulin sensitivity.

Familial combined hyperlipidemia (FCHL) is a common genetic lipid disorder that is present in 10% of patients with premature coronary artery disease (CAD). It was the objective of the present study to evaluate the possible involvement of the PPARA locus in the pathophysiology of FCHL. Mutation detection analyses of the six coding PPARA exons resulted in the identification of four novel variants, [C/T] intron 3, S234G, [G/A] intron 5, and [C/A] 3(') UTR in three FCHL probands, whereas no novel variants were identified in spouses. In a case-control study, markers D22S275 and D22S928 were shown not to be associated with FCHL. However, D22S928, mapped within 1Mb of the PPARA gene, was shown to have a modifying effect on plasma apoCIII concentrations (P=0.011) and the combined hyperlipidemic FCHL phenotype (P=0.038). In addition two PPARA polymorphisms in intron 2 and 7 were studied, but these were not associated with FCHL. The frequency of the L162V variant was less in FCHL probands (1.98%) compared to that in spouses (4.84%). These results clearly demonstrate the genetically complex nature of FCHL and identify the PPARA gene as a modifier of the FCHL phenotype.