Association of Taq 1B CETP polymorphism with insulin and HOMA levels in the population of the Canary Islands

Abstract

Background and aims: Cholesteryl ester transfer protein (CETP) is an enzyme with a key role in lipoprotein metabolism. A common genetic polymorphism, the Taq 1B, influences CETP activity and HDL-cholesterol levels, with individual homozygotes for the B1 allele exhibiting higher enzyme activity and lower HDL-cholesterol levels than carriers of at least one B2 allele. Our aim was to analyze the influence of Taq 1B CETP polymorphism on cardiovascular risk factors in a representative sample of adult subjects from Canary population.

Methods and result: A total of 518 adult subjects from the Canary Islands, enrolled in a nutritional survey (the ENCA study), were included. The Taq 1B polymorphism was analyzed by PCR-RFLP. Compared with individuals with at least one B2 allele, and after adjusting for age, sex, BMI, waist perimeter, smoking and alcohol intake, carriers of the B1B1 genotype showed lower HDL-cholesterol levels (geometric mean (95% CI): 46.6 (44.5-48.8) vs. 50.6 (49.1-52.9)mg/dl; P=0.003); and higher insulin (geometric mean (95% CI): 11.1 (10.5-11.9) vs. 10.0 (9.5-10.5μU/ml; P=0.008) and HOMA levels (geometric mean (95% CI): 2.3 (2.1-2.5) vs. 2.1 (1.9-2.1); P=0.009). In addition, the B1B1 genotype was more frequent in individuals who had low levels of HDL-cholesterol according to the National Cholesterol Education Program Adult Treatment Panel III (NCEP-ATP III) criteria (Odds Ratio (OR): 1.563; 95% CI: 1.04-2.34; P=0.030), and in those included in the upper quartile of insulinemia (OR: 1.90; 95% CI: 1.20-3.03; P=0.007) and HOMA (OR: 1.61; 95% CI: 1.02-2.57; P=0.043).

Conclusion: The observed influence of Taq 1B polymorphism on insulin levels and HOMA highlights the possible role of CETP in the regulation of glucose homeostasis.