Role of Fatty Acid-Binding Protein 2 Ala54Thr Genotype on Weight Loss and Cardiovascular Risk Factors after a High-Protein/Low-Carbohydrate versus a Standard Hypocaloric Diet during 9 Months

Abstract

Background: It has been found that the expression of fatty acid-binding protein 2 gene mRNA is under dietary control. The polymorphism Ala54Thr of this protein was associated with high insulin resistance. Objective: The aim of our study was to investigate the influence of Thr54 polymorphism on metabolic response, weight loss and serum adipokine levels secondary to high-protein/low-carbohydrate vs. standard hypocaloric diets during 9 months. Design: A population of 193 obese subjects was analyzed in a randomized trial. A nutritional evaluation was performed at the beginning and at the end of a 9-month period in which subjects received 1 of 2 diets (diet HP: high-protein/low-carbohydrate vs. diet S: standard diet). Results: With both diets and in both genotype groups, body mass index, weight, fat mass, waist circumference, systolic blood pressure and leptin levels decreased. With both diets and only in wild genotype (diet HP vs. diet S), glucose (-6.2 ± 2.1 vs. -4.9 ± 2.0 mg/dl; p < 0.05), insulin levels (-5.0 ± 3.9 vs. -2.0 ± 2.1 UI/l; p < 0.05), homeostasis model assessment for insulin resistance (HOMA-R) (-1.1 ± 0.9 vs. -0.7 ± 1.0 units; p < 0.05) decreased. The improvement in these parameters was higher with diet HP than HS. With both diets and only in the wild genotype, total cholesterol and LDL-total cholesterol levels decreased. Conclusion: Carriers of Thr54 allele have a different metabolic response after weight loss than wild type non-A carriers obese, with a lack of decrease of LDL-cholesterol, glucose, insulin levels and HOMA-R.