Cholesteryl Ester Transfer Protein Taq1B Polymorphism in an Angiographically Assessed Turkish Population: No Effects on Coronary Artery Disease Risk

Associations of Cholesteryl Ester Transfer Protein TaqIB Polymorphism with the Composite Ischemic Cardiovascular Disease Risk and HDL-C Concentrations: A Meta-Analysis

BACKGROUND

Previous studies have evaluated the associations between the cholesteryl ester transfer protein (CETP) TaqIB polymorphism (rs708272), the risk of developing composite ischemic cardiovascular disease (CVD) and the concentration of high-density lipoprotein cholesterol (HDL-C), but results remain controversial. The objective of this study was to investigate whether a relationship exists between these factors.

METHODS

We conducted a meta-analysis of available studies to clarify the associations of the CETP TaqIB polymorphism with HDL-C concentration and the composite ischemic CVD risk in both Asians and Caucasians. All statistical analyses were done with Stata 12.0.

RESULTS

Through utilization of the Cochrane Library, Embase, PubMed, Web of Science, Springer, China Science and Technology Journal Database, China National Knowledge Infrastructure, Google Scholar, and Baidu Library, a total of 45 studies from 44 papers with 20,866 cases and 21,298 controls were combined showing a significant association between the CETP TaqIB variant and composite ischemic CVD risk. Carriers of allele TaqIB-B1 were found to have a higher risk of composite ischemic CVD than non-carriers: OR = 1.15, 95% CI = 1.09-1.21, p < 0.001. Meanwhile, 28 studies with 23,959 subjects were included in the association between the CETP TaqIB polymorphism and the concentration of HDL-C. RESULTS suggested that carriers of the B1B1 genotype had lower concentrations of HDL-C than those of the B2B2 genotype: SMD = 0.50, 95% CI = 0.36-0.65, p < 0.001.

CONCLUSIONS

The synthesis of available evidence demonstrates that the CETP TaqIB polymorphism protects against composite ischemic CVD risk and is associated with a higher HDL-C concentration in both Asians and Caucasians.

Circulating cholesteryl ester transfer protein and coronary heart disease: mendelian randomization meta-analysis

BACKGROUND

The cholesteryl ester transfer protein (CETP) plays a central role in reverse cholesterol transport. Currently, it remains unresolved whether circulating CETP is causally associated with coronary heart disease (CHD). We aimed to investigate this causal association using CETP gene rs708272 polymorphism as an instrument in a Mendelian randomization meta-analysis.

METHODS AND RESULTS

We searched PubMed and EMBASE before May 2014. Data and study quality were assessed in duplicate. Thirty-four articles (17 813 CHD patients and 22 203 controls) were qualified. Overall analyses revealed a significant association of rs708272-B1 allele with a reduced CHD risk compared with B2 allele under allelic (odds ratio and 95% confidence interval: 0.87 and 0.82-0.92; P<0.001), homozygous genotypic (0.74 and 0.66-0.83; P<0.001), and dominant (0.87 and 0.80-0.94; P<0.001) models. Carriers of rs708272-B1B1 genotype (weighted mean difference and 95% confidence interval: -0.21 and -0.41 to 0.00 μg/dL; P=0.052) or B1 allele (-0.15 and -0.30 to 0.00 μg/dL; P=0.056) had a marginally lower circulating CETP level compared with B2B2 genotype carriers. In Mendelian randomization analysis, there was a 25% (odds ratio and 95% confidence interval: 0.75 and 0.19-0.91) and a 17% (0.83 and 0.41-0.96) significantly reduced risk of CHD by a reduction of 0.2 μg/mL in circulating CETP for the comparison of B1B1 genotype and B1 allele with B2B2 genotype, respectively. There were low probabilities of publication bias.

CONCLUSIONS

Our findings demonstrate that the long-term genetically reduced circulating CETP might be causally associated with the low risk of CHD.

Association between cholesteryl ester transfer protein TaqIB variants and risk of coronary artery disease and diabetes mellitus in the population of western Iran

AIMS

To shed light on the previously inconsistent results about the association of cholesteryl ester transfer protein TaqIB (CETP TaqIB) variants, high-density lipoprotein cholesterol (HDL-C) levels, and the risk of coronary artery disease (CAD) and type 2 diabetes mellitus (T2DM).

METHODS

To determine the frequency of CETP TaqIB variants and to examine the possible association between CETP TaqIB polymorphism with CAD and T2DM, we studied 207 unrelated patients with CAD, 101 patients with T2DM, and 92 controls. The CETP TaqIB variants were detected by polymerase chain reaction-restriction fragment length polymorphism.

RESULTS

Logistic regression analysis indicated that the B1 allele of CETP was significantly associated with increased risk of CAD (odds ratio, OR 1.65 [95% confidence interval, CI 1.2-2.3, p=0.005]) and T2DM (OR 1.7 [95% CI 1.13-2.54, p=0.005]). Adjusted logistic regression analysis for the effects of age, sex, hypertension, diabetes, and hyperlipidemia was performed; and a significant association was found between the B1 allele and risk of CAD (OR 1.9 [95% CI 1-3.6, p=0.049]) in patients with CAD. There were no associations between the CETP alleles and the levels of triglycerides, total cholesterol, low-density lipoprotein cholesterol, and HDL-C in studied groups.

CONCLUSIONS

The results of the present study revealed that the CETP B1 allele is associated with increased risk of CAD and T2DM independent of plasma HDL-C level in our population.