Interaction between dietary fat intake and the cholesterol ester transfer protein TaqIB polymorphism in relation to HDL-cholesterol concentrations among US diabetic men

Abstract

Background: A low plasma HDL-cholesterol concentration is a major characteristic of diabetic dyslipidemia. HDL concentrations are determined by both environmental factors and genetic factors. Cholesterol ester transfer protein (CETP) plays an important role in the regulation of HDL metabolism, and the TaqIB polymorphism of the CETP gene has been associated with elevated HDL concentrations.Objective: We examined the association between the CETP TaqIB polymorphism and plasma HDL concentrations and evaluated whether this association was modified by dietary fat intake.Design: We followed 780 diabetic men aged 40–75 y who participated in the Health Professionals Follow-Up Study since its initiation in 1986. The participants had confirmed type 2 diabetes and were free of cardiovascular disease at the time blood was drawn.Results: After adjustment for age, smoking, alcohol consumption, fasting status, hemoglobin A1c, physical activity, total energy intake, and body mass index, HDL concentrations were significantly higher in men with the B2B2 or B1B2 genotype than in those with the B1B1 genotype (adjusted x̄ ± SE: 37.9 ± 0.02, 40.3 ± 0.01, and 42.6 ± 0.02 mg/dL for B1B1, B1B2, and B2B2, respectively; P for trend = 0.0004). This inverse association of the B1 allele with plasma HDL concentrations existed for those with a high consumption of animal fat (P for interaction = 0.02), saturated fat (P for interaction = 0.02), and monounsaturated fat (P for interaction = 0.04).Conclusion: These data confirmed a significant effect of the CETP Taq1 gene on HDL concentrations and suggested a potential interaction between the CETP TaqIB polymorphism and intake of dietary fat on plasma HDL concentration.