Association of cholesteryl ester transfer protein-TaqIB polymorphism with variations in lipoprotein subclasses and coronary heart disease risk: the Framingham study

Cholesteryl ester transfer protein (CETP) facilitates the exchange of triglycerides and cholesteryl esters between lipoprotein particles, a key step in reverse cholesterol transport in humans. Variations at the CETP locus have been shown to be determinants of the levels and activity of CETP and high density lipoprotein (HDL) plasma concentration. The associations of the common CETP polymorphism, TaqIB in intron 1, with lipoprotein levels and particle size distribution, CETP activity, and coronary heart disease (CHD) risk were examined in a population-based sample of 1411 men and 1505 women from the Framingham Offspring Study. The B2 allele frequency was 0.444 in men and 0.433 in women, and its presence was significantly (P<0.05) associated with decreased CETP activity. B1B1 men had lower HDL cholesterol (HDL-C) levels (1.07 mmol/L) compared with B1B2 (1.14 mmol/L) and B2B2 (1.18 mmol/L) men (P<0.001). Likewise, B1B1 women had lower HDL-C levels (1.40 mmol/L) compared with B1B2 (1.46 mmol/L) and B2B2 (1.53 mmol/L) women (P<0.001). In men, the B2 allele was associated with increased particle size for HDL and low density lipoprotein. In women, a similar effect was demonstrated only for HDL particle size. The odds ratio for prevalent CHD associated with the B2 allele was 0.696 (P=0.035) in men. After adjusting for age, body mass index, systolic blood pressure, diabetes, smoking, alcohol consumption, beta-blocker use, total cholesterol, and HDL-C, this odds ratio was 0.735 (P=0.187), suggesting that the protective effect of the B2 allele was due in part to its association with HDL-C levels. No significant protective effects were observed in women. These data demonstrate that variation at the CETP gene locus is a significant determinant of HDL-C levels, CETP activity, and lipoprotein size in this population. Moreover, these effects appear to translate into a lower CHD risk among those men with the B2 allele.     

Association of TaqIB polymorphism in the cholesteryl ester transfer protein gene with plasma lipid levels in a healthy Spanish population

Genetic variants at the cholesteryl ester transfer protein (CETP) locus have been associated with CETP activity and mass, as well as plasma high density lipoprotein cholesterol (HDL-C) and apolipoprotein A-I levels. We have examined allele frequencies and lipid associations for the common CETP TaqIB polymorphism in a sample of 514 healthy subjects (231 men, mean age 37.4 years, and 283 women, mean age 35.7 years) residing in Valencia (Spain). The frequency of the less common TaqIB2 allele (0.351; 95% CI: 0.322-0. 380) was significantly lower than those reported for Northern European populations. Consistent with previous studies, we found a significant association of the TaqIB polymorphism with HDL-C levels. Homozygotes for the B1 allele had lower HDL-C levels than subjects carrying the B2 allele (P trend<0.001 and 0.002, for men and women, respectively). No statistically significant genotype effects were observed for any of the other lipid measures. Multivariate models including TaqIB genotype, body mass index, smoking, alcohol, physical activity, marital status and education were fitted to predict HDL-C levels. The TaqIB polymorphism was consistently an independent predictor of HDL-C levels (P<0.001), and explained 5.8% of its variance. To evaluate gene-environmental interactions, first order interaction terms were tested into the multivariate model. No statistically significant interactions between the TaqIB genotypes and smoking, alcohol, physical activity or education were detected. In conclusion, we observed a significant association of the TaqIB polymorphism with HDL-C levels, which remained consistent across different levels of behavioral factors. Moreover, we found that the TaqIB2 allele frequency was lower in our sample than in other European populations, which could be a contributing factor to the unexpectedly high prevalence of coronary heart disease observed in the region of Valencia.     

The -629C>A polymorphism in the CETP gene does not explain the association of TaqIB polymorphism with risk and age of myocardial infarction in Icelandic men.

The aim of this study was to examine whether the well-established effect of the common TaqIB polymorphism in intron 1 of the gene for cholesterol ester transfer protein (CETP) on high density lipoprotein cholesterol (HDL-C) concentration and increased risk of myocardial infarction (MI), could be explained by the recently identified -629C>A functional polymorphism in the promoter. Non-fatal MI cases (388 male) and a control group of 794 healthy men were recruited from the 30 year long prospective Reykjavik Study. In the healthy men the frequency of the TaqIB B2 allele was 0.47 (95% CI: 0.44-0.50) and there was a strong allelic association with the -629A allele (D=-0.21, P<0.0001), which had a frequency of 0.52 (95% CI: 0.49-0.56). B2B2 homozygotes displayed 15% higher HDL-C levels than subjects homozygous for the B1 allele (P<0.0001). Homozygotes for the -629A allele displayed 14% higher HDL-C concentrations than subjects homozygous for the -629C allele (P<0.0001). The frequencies of the alleles associated with lower HDL-C were significantly higher in cases compared with controls, 0.59 versus 0.53 (TaqIB B1) and 0.52 versus 0.48 (-629 C) respectively (P<0.05 for both). There was a significantly higher risk for MI in B1B1 homozygotes (OR=1.44, 95% CI: 1.10-1.87, P<0.01), compared to the other genotypes combined. This was not observed for the CC homozygotes (OR=1.16, 95% CI: 0.87-1.54). In addition, homozygotes for the TaqI B2 allele experienced a first MI 2 years later than men with other genotypes, 59 versus 61 years (P<0.05). This effect was not seen for the promoter polymorphism. These results strongly confirm the role of the CETP gene and the TaqIB variant as a risk factor for MI and suggest that another functional polymorphism is yet to be discovered in the CETP gene, that will explain the effect on MI associated with TaqIB observed in this study.     

Association of cholesteryl ester transfer protein activity and TaqIB polymorphism with lipoprotein variations in Japanese subjects

Cholesteryl ester transfer protein (CETP) facilitates the transfer of cholesteryl ester from high-density lipoprotein (HDL) to apolipoprotein (apo)B-containing lipoproteins, whereby it potentially regulates steady-state concentrations of HDL-cholesterol (HDL-C), as well as low-density lipoprotein-cholesterol (LDL-C). We performed a multicenter trial to assess the association of CETP activity with plasma lipoprotein levels in 591 Japanese subjects. Women had significantly higher CETP activity (15%) and mass (24%) compared to men. For both genders CETP activity was negatively correlated with HDL-C and HDL(2)-C, but positively correlated with LDL-C. B2 allele frequency in TaqIB polymorphism was 40%, with no gender difference. TaqIB genotypes were significantly associated with CETP activity and HDL-C level (both P <.001). B1B1 had the highest CETP activity and the lowest HDL-C concentrations, whereas B2B2 had the lowest CETP activity and the highest HDL-C concentrations. However, no statistically significant differences in triglycerides (TG) or LDL-C were observed across TaqIB genotypes. Multivariate analysis revealed that determinants of HDL-C were age, gender, body mass index (BMI), smoking, alcohol intake, exercise, CETP activity, and TG, and for LDL-C were BMI, age, and CETP. These data demonstrate that CETP activity is a significant determinant of HDL-C and LDL-C levels and that TaqIB CETP gene polymorphism affects CETP activity and HDL-C level in Japanese population examined.     

The association between high-density lipoprotein cholesterol level and cholesteryl ester transfer protein TaqIB gene polymorphism is influenced by alcohol drinking in a population-based sample

Cholesteryl ester transfer protein (CETP) is a key enzyme in high-density lipoprotein (HDL) cholesterol metabolism. We studied the association between CETP TaqIB polymorphism and the HDL cholesterol levels considering environmental factors in a population-based sample consisting of 1729 participants who did not use lipid-lowering agents (659 men and 1070 women). The CETP TaqIB genotypes were determined by PCR-RFLP analysis. The serum HDL cholesterol levels of female participants with the B2B2 genotype were significantly higher than those with other genotypes (p<0.001). Multiple regression analysis with covariates such as age, waist to hip (W/H) ratio, alcohol drinking, current smoking, non-HDL cholesterol, and logarithm of triglyceride revealed that the CETP TaqIB genotype was an independent determinant of HDL cholesterol levels in men (p=0.049) and women (p<0.001). Subgroup analysis revealed that an interaction was observed between the CETP TaqIB polymorphism and alcohol consumption in the regulation of HDL cholesterol levels in men (p=0.049) and women (p=0.022). No interactions were observed between the CETP TaqIB polymorphism and current smoking status, body mass index, or W/H ratio in the regulation of HDL cholesterol levels. The association between the CETP TaqIB polymorphism and HDL cholesterol levels was more evident in alcohol consumers than in non-drinkers.     

Loci for CETP,LPL, LIPC,and APOC3 affect plasma lipoprotein size and sub-population distribution in Hispanic and non-Hispanic white subjects: the Columbia University BioMarkers Study

BACKGROUND AND AIM: The effect of genetic variation on plasma lipoproteins and their subfraction distribution was examined. METHODS AND RESULTS: Forty Hispanic men and 223 women and 42 non-Hispanic white men and 53 women participated in the study. Genotypes for cholesteryl ester transfer protein (CETP TaqIB), hepatic lipase (LIPC -480 C > T), lipoprotein lipase (LPL S447X), and apolipoprotein CIII (APOC3--455T > C) were determined by polymerase chain reaction. Lipoprotein particle size distribution was determined by nuclear magnetic resonance. For all but APOC3, genotype effects were homogeneous in the ethnic/racial groups and men and women. Effects were seen primarily in the women. Compared to women carriers of the common CETP B1 allele, B2B2 women had significantly higher plasma levels of high-density lipoprotein cholesterol (HDL-C) (16.4.0%, p = 0.001), reflected in the level of larger HDL particles (21.9%, p = 0.001), and larger mean particle size of HDL (2.3%, p = 0.01) and low-density lipoproteins (LDL) (1.3%, p = 0.02). Compared to LPL 447S homozygous women carriers of the LPL 447X allele had significantly lower levels of very-low-density lipoprotein-triglyceride (VLDL-TG) (21.0%, p = 0.02). For APOC3, there was significant gender:genotype interaction with the genotype differences seen only in the men. Compared to men homozygous for the -455T allele, carriers of -455C had higher levels of VLDL-TG (71.4%, p = 0.0001), reflected in a larger mean VLDL particle size (13.7%, p = 0.009). LIPC genotype was not associated with significant effects on any of these traits. CONCLUSION: These data confirm the role of genetic variants of CETP, LPL and APOC3 in determining the relationship between VLDL, LDL and HDL particles.     

A polymorphism of the cholesteryl ester transfer protein gene predicts cardiovascular events in non-smokers in the West of Scotland Coronary Prevention Study.

AIM: The association of cholesteryl ester transfer protein (CETP) gene polymorphisms with risk of a cardiovascular event and whether any association was explained by an influence on high-density lipoprotein (HDL) levels or low-density lipoprotein (LDL) size was tested in the West of Scotland Coronary Prevention Study (WOSCOPS). Gene-smoking and gene-treatment interactions were investigated. METHODS AND RESULTS: Cases (n=498) and controls (n=1108) were typed for TaqIB, C(-631)A, C(-629)A, I405V and D442G CETP polymorphisms. Homozygotes for the TaqIB2 allele (B2B2) had a 30% reduced risk of a cardiovascular event (odds ratio [OR] 0.70, CI(95)0.51-0.96, P=0.03) compared to B1B1 homozygotes. Inclusion of HDL or LDL diameter in multivariate analysis only marginally attenuated the relationships. Non-smokers, but not smokers, showed a dose-dependent association of risk with TaqIB genotype. Treatment benefit was not significantly different in B1B1 (OR 0.71, pravastatin vs placebo), B1B2 (OR 0.68) and B2B2 (OR 0.61) individuals. The other CETP polymorphisms studied had no significant association with cardiovascular risk. Haplotype analysis did not add to the information given by the individual polymorphisms. CONCLUSION: The association between CETP TaqIB genotype and cardiovascular risk is primarily in non-smokers, is not fully explained by effects on HDL levels or LDL size, and the benefit of pravastatin treatment was not influenced by this polymorphism.     

A prospective study of TaqIB polymorphism in the gene coding for cholesteryl ester transfer protein and risk of myocardial infarction in middle-aged men

BACKGROUND: Molecular variations in the gene coding for the cholesteryl ester transfer protein (CETP) such as the TaqIB polymorphism are associated with higher plasma high-density lipoprotein (HDL) concentration. However, whether this polymorphism is associated with risk of myocardial infarction (MI) is uncertain. METHODS AND RESULTS: In a prospective cohort of 14916 apparently healthy men enrolled in the Physicians' Health Study, allelic status for the TaqIB polymorphism in the CETP gene was determined among 384 participants who subsequently developed a first MI (cases) and among an equal number of age and smoking-matched participants who remained free of cardiovascular disease during follow-up (controls). Overall, the B2B2 genotype was present in 17% of the study participants and was associated with higher HDL cholesterol levels (mean mg/dl [+/- S.D.], 45 +/- 11 for the B1B1 genotype, 48 +/- 13 for the B1B2 genotype and 50 +/- 12 for the B2B2 genotype; P=0.01). However, the risk of developing MI did not differ significantly across these three genotypes. After adjustment for coronary risk factors (but not HDL), the relative risks for future MI were 1.12(95% CI 0.74-1.70) for the B1B2 genotype and 0.95(95% CI 0.54-1.66) for the B2B2 genotype, compared with the B1B1 genotype. In subgroup analysis of individuals with low HDL levels, B2B2 genotype appeared to have a lower risk of MI compared with the B1B1 genotype. However, participants with high HDL were at lower risk of developing MI regardless of their CETP genotype. CONCLUSIONS: In this prospective study of apparently healthy middle-aged US men, carriers of the B2 allele of the TaqIB in the CETP gene had higher HDL concentrations, but did not have lower risk of MI. CONDENSED ABSTRACT: In a cohort of apparently healthy middle-aged US men, the relation between CETP genotype and MI risk was prospectively examined in a nested case-control study. After adjusting for coronary risk factors (but not HDL), the 9-year risk of developing MI did not differ significantly by genotype. Comparing to the B1B1 genotype, the relative risks for future MI were 1.12 (95% CI 0.74-1.70) for the B1B2 genotype and 0.95 (95% CI 0.54-1.66) for the B2B2 genotype.     

The interactive effects of hepatic lipase gene promoter polymorphisms with sex and obesity on high-density-lipoprotein cholesterol levels in Taiwanese-Chinese

OBJECTIVES: Hepatic lipase (HL) is involved in the metabolism of several lipoproteins and plays a key role in reverse cholesterol transport. The aim of the current study was to test the statistical association between two HL gene promoter polymorphisms (HL-514C/T and HL-250G/A) and lipoprotein profiles in a Taiwanese-Chinese population. METHODS: A sample population of 716 Taiwanese-Chinese individuals was analyzed. DNA was extracted from the blood and genotypes were determined by polymerase chain reaction, restriction enzyme digestion, and agarose gel electrophoresis. RESULTS: Analysis of the data revealed that these two polymorphisms are in strong linkage disequilibrium (D/D(max)=0.97, P<0.001). A significantly lower total cholesterol/HDL-C ratio was noted for carriers with the -514T and -250A alleles compared to non-carriers (P=0.007 and 0.004, respectively). A significant trend of the association was also found on the high levels of high-density-lipoprotein cholesterol (HDL-C) among carriers with the -514T and -250A alleles as opposed to that of non-carriers (P=0.030 and 0.023, respectively). Multivariate analysis has demonstrated that the effects of HL-514C/T and HL-250G/A polymorphisms on HDL-C levels were not affected by subjects' sex, body mass index, plasma triglyceride levels and the cholesterol ester transfer protein gene TaqIB polymorphism. Subgroup analysis on each sex has revealed that the two studied polymorphisms were significantly associated with HDL-C levels among males but not significant in women. The same association between obese and non-obese men was not consistent. The P-value of the respective polymorphisms on HDL-C levels were 0.012 and 0.002 among obese men, but not significant among non-obese men. CONCLUSION: Analysis of our data revealed an independent association between the HL gene promoter polymorphisms and HDL-C levels in Taiwanese-Chinese. The data also suggests that the HL-514C/T and HL-250G/A polymorphisms interact with sex and obesity on HDL-C levels. The findings give clues for identifying high risk population in preventive medicine and clinical diagnosis. The subsequent impacts on treatment profiles and prognosis were derived from this study.     

Taq1B CETP polymorphism, plasma CETP, lipoproteins, apolipoproteins and sex differences in a Jewish population sample characterized by low HDL-cholesterol

Mean high-density lipoprotein cholesterol (HDL-C) concentrations are low in the Jewish population of Israel. With this in mind we assessed the association of the Taq1B CETP polymorphism, plasma CETP mass and plasma lipid, lipoprotein and apolipoprotein concentrations in a sample of 884 Jerusalem residents aged 28-32. The allele frequency (0.435 +/- 0.017(S.E.)) is similar to that reported elsewhere. There was a strong (apparently codominant) association of the Taq1 B allele with plasma CETP in both sexes, and an inverse association with HDL-C and apo A-1, significant in women and undiminished upon adjustment for plasma CETP. There was evidence in this population for an admixture of two plasma CETP distributions, with 9% belonging to a distribution with the higher mean, pointing to a possible major gene effect. Mean plasma CETP was higher in women than men. Plasma CETP was inversely associated with HDL-C in men but not in women (P< 0.05 for the sex difference, multivariate analysis), inversely related to the HDL-C/apo A-1 ratio in men and positively related in women (P < 0.005 for the sex difference), and was positively associated with total cholesterol (TC) and low-density lipoprotein cholesterol in both sexes, and with the TC/HDL-C ratio and apo B in men alone. The sex differences may reflect dissimilarities in the regulatory function of CETP in lipid exchange. The absence of an unusual allele frequency of the Taq1B CETP polymorphism and its relatively modest association with HDL-C argue against an important role for this or strongly linked sites in determining the low population levels of HDL-C in Israel.     

Association between well-characterized lipoprotein-related genetic variants and carotid intimal medial thickness and stenosis: The Framingham Heart Study

OBJECTIVE: To determine the association of well-characterized lipoprotein-related genetic variants with carotid intimal medial thickness (IMT) and stenosis. METHODS: 3380 men and women from the Framingham Offspring Study underwent carotid ultrasound to determine carotid IMT and stenosis>/=25%. We genotyped 12 variants in 10 lipoprotein-related genes known to be associated with significant differences in lipoprotein levels. RESULTS: For most of the variants, there was no association with carotid IMT. In multivariable, sex-specific analyses, the rare allele of the cholesterol ester transfer protein (CETP) TaqIB variant was associated with lower ICA IMT in men. Hypertension was associated with higher ICA IMT only in male carriers of the rare allele of the APOCIII Sst-1 variant (p for the interaction=0.041). In analyses of carotid stenosis in male, carriers of the lipoprotein lipase (LPL) N291S rare variant showed a higher risk of carotid stenosis (OR=2.59, 95% confidence interval: 1.11-6.02, p=0.028) compared to NN genotype. CONCLUSIONS: While there is no evidence for a significant association of several common lipoprotein-related genetic variants with carotid IMT, our results are consistent with the previously reported role of CETP and LPL genetic variants in cardiovascular risk and the possible modulation of the association between hypertension and carotid IMT by APOCIII Sst-1 variant.     

Cholesteryl ester transfer protein and atherosclerosis in Japanese subjects: a study based on coronary angiography.

We undertook a cross-sectional analysis on CETP and atherosclerosis among Japanese subjects, by means of CETP mass assay, its gene polymorphism and coronary angiogram. The 110 consecutive patients who underwent coronary angiography were enrolled into the study except for those over 70 years and taking lipid-lowering drugs. Association was analyzed among plasma lipid and lipoproteins, CETP mass, its gene polymorphisms and the finding in coronary angiography. Four CETP-deficiency heterozygotes were identified and excluded from the analysis. CETP mass level showed neither significant correlation with the coronary score (CS) (r=0.06, P=0.52) nor the difference between the groups eventually diagnosed as coronary heart disease (CHD) positive and CHD negative (2.36+/-0.57 vs. 2.24+/-0.21, P=0.24). CETP mass correlated with the total and LDL cholesterol (r=0.43, P<0.001; r=0.36, P<0.001, respectively) but not with HDL cholesterol (r=0.08, P=0.40). While I405V polymorphism had no impact on CETP mass, HDL cholesterol or CS, CETP mass was low with TaqIB polymorphism (B1B1>B2B2, P<0.05) only in the low CS group (<4). Among the lipid and lipoprotein, HDL cholesterol had a greater impact than LDL cholesterol on coronary atherosclerosis. We concluded that CETP mass in plasma does not correlate with coronary atherosclerosis as whole in the non-CETP-deficient. However, the B2B2 genotype in CETP TaqIB polymorphism, only when it decreases the CETP level, may act as a protective factor against atherosclerosis. It should also be noted that CETP mass in general correlates to total and LDL cholesterol, so that it would be an indirect atherogenic parameter.     

The effect of cholesteryl ester transfer protein -629C->A promoter polymorphism on high-density lipoprotein cholesterol is dependent on serum triglycerides

CONTEXT: The -629C-->A cholesteryl ester transfer protein (CETP) promoter polymorphism is a determinant of HDL cholesterol (HDL-C). The effect of the closely linked CETP TaqIB polymorphism on HDL-C has been suggested to be modified by obesity and hyperinsulinemia. OBJECTIVE: Because the CETP-mediated cholesteryl ester transfer out of HDL is stimulated by high triglycerides, we hypothesized that triglycerides modify the effect of the CETP -629C-->A promoter polymorphism on HDL-C. DESIGN: In 7083 nondiabetic subjects of the PREVEND population, the -629C-->A promoter polymorphism, HDL-C, serum triglycerides, waist circumference, and insulin resistance (HOMA(ir)) were determined. Serum apolipoprotein A-I was available in 6948 subjects. The TaqIB polymorphism was also assessed. SETTING: The study is set in the general community. RESULTS: HDL-C and serum apolipoprotein A-I were on average 0.14 mmol/liter and 0.05 g/liter higher in -629AA (22.9%) compared to -629CC (26.8%) homozygotes (P < 0.001 for both). This genotype effect on HDL-C was on average 0.15 mmol/liter in the lowest triglyceride tertile but only 0.08 mmol/liter in the highest tertile (P < 0.01). Multiple regression analysis showed that HDL-C was determined by the CETP promoter variant (P < 0.001), gender (P < 0.001), triglycerides (P < 0.001), and interactions between triglycerides and genotype (P < 0.05), between triglycerides and gender (P < 0.05), and between genotype and gender (P < 0.05), independently from waist, HOMA(ir), alcohol use, age, and use of lipid-lowering drugs. The TaqIB polymorphism also interacted with triglycerides on HDL-C. The -629C-->A promoter polymorphism did not interact with obesity and HOMA(ir) on HDL-C. CONCLUSIONS: The HDL-C-raising effect of the CETP -629A allele is diminished with higher triglycerides, which may be explained by a predominant effect of triglyceride-rich lipoproteins over circulating CETP itself on cholesteryl ester transfer out of HDL with rising triglycerides.     

Plasma cholesteryl ester transfer protein concentrations predict cardiovascular events in patients with coronary artery disease treated with pravastatin

OBJECTIVE: The B1B1 variant of the cholesteryl ester transfer protein (CETP) TaqIB polymorphism and high plasma CETP concentrations are associated with favourable angiographic outcomes in pravastatin-treated patients suffering from coronary artery disease (CAD). The purpose of the present study was to test whether CETP TaqIB genotypes and/or plasma CETP concentrations at baseline also predict clinical end-points in patients with CAD. DESIGN: Prospective longitudinal observational study. SETTING: Primary care doctors (n=88) and hospitals (n=7) in Austria. SUBJECTS: A total of 1620 men and women with preexisting CAD were recruited and plasma lipids were determined at study entry. 1389 hypercholesterolaemic patients were included and 1002 patients completed the follow-up. INTERVENTIONS: In all patients treatment with pravastatin was started and patients were followed up for 2 years. MAIN OUTCOME MEASURES: Cardiovascular events. RESULTS: One hundred patients suffered at least one cardiovascular event. We observed significantly more events in patients within the lowest compared with the highest quartile of plasma CETP concentrations (odds ratio 3.20, CI95 1.65-6.23; P=0.001, adjusted for known risk factors of CAD). No significantly different numbers of cardiovascular events were found between CETP TaqIB genotypes. CONCLUSIONS: Plasma CETP concentrations, but not CETP TaqIB genotypes, predict cardiovascular events in patients with CAD treated with pravastatin. Despite higher LDL cholesterol concentrations, high plasma CETP concentrations at baseline are associated with fewer cardiovascular events compared with low plasma CETP concentrations in CAD patients treated with pravastatin.     

Is plasma oxidized low-density lipoprotein, measured with the widely used antibody 4E6, an independent predictor of coronary heart disease among U.S. men and women?

OBJECTIVES: Our aim was to examine whether circulating oxidized low-density lipoprotein (oxLDL) is a predictor of coronary heart disease (CHD) independent of lipid markers and to compare oxLDL, apolipoprotein B100 (apoB), and total cholesterol (TC)/high-density lipoprotein-cholesterol (HDL-C) ratio as predictors of CHD. BACKGROUND: Measurement of circulating oxLDL with antibody 4E6, has been widely used in many studies; however, few large prospective studies have examined whether this marker is a predictor of CHD independent of lipids and compared oxLDL with other important lipid predictors. METHODS: After 6 years of follow-up among 18,140 men from the HPFS (Health Professionals Follow-up Study) and 8 years among 32,826 women from the Nurses' Health Study who provided blood samples at baseline, we identified incident nonfatal myocardial infarction or fatal CHD in 266 men and 235 women. Each case was matched with two control subjects by age, smoking, and time of blood draw. The oxLDL was measured via enzyme-linked immunosorbent assay with antibody 4E6 against oxidized apoB. RESULTS: Among both men and women, oxLDL was significantly related to risk of CHD in multivariate analysis before adjustment for any lipid markers. However, when oxLDL, LDL cholesterol, HDL-C, and triglycerides were mutually adjusted, oxLDL was no longer predictive. When oxLDL and apoB were mutually adjusted, only apoB was predictive of CHD. Similar results were found when oxLDL and TC/HDL-C ratio were mutually adjusted. CONCLUSIONS: Our results suggest that circulating oxLDL, measured with antibody 4E6, is not an independent overall predictor of CHD after adjustment of lipid markers and is less predictive in development of CHD than apoB and TC/HDL-C ratio.     

Alcohol consumption and cardiovascular mortality accounting for possible misclassification of intake: 11-year follow-up of the Melbourne Collaborative Cohort Study

AIMS: To investigate the relationship between usual daily alcohol intake, beverage type and drinking frequency on cardiovascular (CVD) and coronary heart disease (CHD) mortality, accounting for systematic misclassification of intake. DESIGN: Prospective cohort study with mean follow-up of 11.4 years. Setting The Melbourne Collaborative Cohort Study, Australia. PARTICIPANTS: A total of 38 200 volunteers (23 044 women) aged 40-69 years at baseline (1990-1994). MEASUREMENTS: Self-reported alcohol intake using beverage-specific quantity-frequency questions (usual intake) and drinking diary for previous week. FINDINGS: Compared with life-time abstention, usual daily alcohol intake was associated with lower CVD and CHD mortality risk for women but not men. For women, the hazard ratio [HR (95% CI)] for CVD for those drinking > 20 g/day alcohol was 0.43 (0.19-0.95; P trend = 0.18), and for CHD, 0.19 (0.05-0.82; P trend = 0.24). Male former drinkers had over twice the mortality risk for CVD [HR = 2.58 (1.51-4.41)] and CHD [HR = 2.91 (1.59-5.33)]. Wine was the only beverage associated inversely with mortality for women. Compared with drinkers who consumed no alcohol in the week before baseline, drinking frequency was associated inversely with CVD and CHD mortality risk for men but not women. HR for men drinking 6-7 days/week was 0.49 (0.29-0.81; P trend = 0.02) for CVD, and 0.49 (0.26-0.92: P trend = 0.23) for CHD. CONCLUSIONS: Usual daily alcohol intake was associated with reduced CVD and CHD mortality for women but not men. This benefit appeared to be mainly from wine, although comparison of beverages was not possible. Drinking frequency was associated inversely with CVD and CHD death for men but not women.     

Contribution of the cholesteryl ester transfer protein gene TaqIB polymorphism to the reduced plasma HDL-cholesterol levels found in abdominal obese men with the features of the insulin resistance syndrome.

OBJECTIVE: The aim of this study was to examine the relation between the CETP-TaqIB polymorphism and reduced plasma HDL-cholesterol levels commonly observed among men characterized by abdominal obesity and features of the insulin resistance syndrome. SUBJECTS: A total of 187 sedentary men, non-smokers and free from metabolic disorders were classified on the basis of their CETP-TaqIB genotype. RESULTS: Plasma HDL and HDL3-cholesterol concentrations as well as the CETP activity were significantly different between the three genotypes, B1B1 men having significantly lower HDL and HDL3-cholesterol levels and higher CETP activity than B2B2 homozygotes. A 2x3 ANOVA was used to determine the source of variation of plasma HDL and HDL2-cholesterol levels among the three genotypic groups of men divided on the basis of either a high (>/=27 kg/m2) or a low (<27 kg/m2) BMI, a high (>/=130 cm2) or a low (<130 cm2) accumulation of visceral adipose tissue assessed by computed tomography, or a low versus a high fasting plasma insulin concentration (using the median value as a cut-off point). The effect of the CETP genotype observed on plasma HDL-cholesterol concentrations was attenuated among men with features of the insulin resistance syndrome. It seems that the expected raising effect of the B2 allele on plasma HDL-cholesterol concentrations was blunted in the presence of a BMI>/=27 kg/m2, a high accumulation of visceral adipose tissue or hyperinsulinaemia. CONCLUSION: Our data indicate that the CETP gene TaqIB polymorphism influences plasma CETP activity on one hand and plasma HDL-cholesterol concentrations on the other hand among men. The association between the TaqIB polymorphism and plasma HDL-cholesterol concentrations is altered by the presence of abdominal obesity and some features of the insulin resistance syndrome.     

Polymorphisms in the NPY and AGRP genes and body fatness in Dutch adults

OBJECTIVE: To investigate the association between DNA polymorphisms in the NPY and AGRP genes and body fatness. DESIGN AND METHODS: The association between the AGRP Ala67Thr or the NPY Leu7Pro polymorphisms and indicators of body fatness (baseline leptin levels, body mass index (BMI) values and prevalence of overweight) are investigated in 582 participants of two large cohorts in The Netherlands (total 18 500 adult men and women), aged 20-40 years whose weight remained relatively constant or whose weight increased substantially (range 5.5-47 kg) during a mean follow-up of 7 years. RESULTS: No consistent associations were found for the indicators of body fatness for men and women. Among women, BMI values, leptin levels and prevalence of overweight were not statistically different for carriers of the mutant alleles compared to that of the non-carriers. Among men, carriers of the Thr67-allele of the AGRP gene had similar leptin levels, but higher BMI values compared to those with the genotyping Ala67/Ala67: mean adjusted BMI 25.6 kg/m2 (95% CI 24.3-27.0) vs 23.9 kg/m2 (23.6-24.3). Also, the risk of being overweight at baseline tended to be higher for male carriers of the Thr67-allele of the AGRP gene (OR 2.52; 95% CI 0.86-7.4). Furthermore, male carriers of the Pro7-allele of the NPY gene had on average higher leptin levels and BMI values vs non-carriers of this allele: 4.7 microg/l (95% CI 3.7-6.0) and 25.7 kg/m2 (95% CI 24.4-27.0) vs 3.1 microg/l (95% CI 2.9-3.4) and 23.9 kg/m2 (95% CI 23.5-24.3), respectively. These male carriers had also a higher risk on being overweight at baseline (OR 3.3 (95% CI 1.2-8.9)) compared to non-carriers of the Pro7-allele. CONCLUSION: The consistent findings among men suggest that the NPY Leu7Pro polymorphism (or another linked marker) might be involved in the development of obesity at younger ages. The findings for the AGRP Ala67Thr were less consistent and need further investigation. Among women, these polymorphisms do not play an important role.