Ala54Thr Polymorphism of Fatty Acid Binding Protein 2, Role on Insulin Resistance and Cardiovascular Risk Factors in Presurgical Morbid Obesity Patients

Abstract

A transition G to A at codon 54 of fatty acid binding protein 2 (FABP2) results in an amino acid substitution (ala 54 to Thr 54). This polymorphism was associated with insulin resistance in some populations. The aim of our study was to investigate the influence of Thr54 polymorphism in the FABP2 gene on obesity anthropometric parameters, cardiovascular risk factors, and adipocytokines in patients with presurgical morbid obesity. A population of 55 morbid obese patients was enrolled. An indirect calorimetry, tetrapolar electrical bioimpedance, blood pressure, a serial assessment of nutritional intake with 3 days of written food records, and biochemical analysis (lipid profile, adipocytokines, insulin, C-reactive protein, and lipoprotein-a) were performed. The statistical analysis was performed for the combined Ala54/Thr54 and Thr54/Thr54 as a mutant-type group and wild-type group (Ala54/Ala54). Twenty nine (52.7%) had the genotype Ala54/Ala54 (wild-type group) and 26 (47.3%) patients had the genotype Ala54/Thr54 (24 patients, 43.7%) or Thr54/Thr54 (two patients, 3.6%; mutant-type group). Insulin (22.4 +/- 16.8 vs. 26.1 +/- 17.1 mg/dl; p = 0.04) and homeostasis model assessment (6.1 +/- 2.1 vs. 6.7 +/- 4.5; p = 0.04) levels were higher in mutant-type group than wild-type group. In mutant-type group, leptin levels (134.8 +/- 83 vs. 206.5 +/- 76 ng/ml; p = 0.03) were higher than wild-type group. Moreover, adiponectin levels (80.9 +/- 39.6 vs. 23.9 +/- 13.8 ng/ml; p = 0.02) were higher in wild-type group than mutant-type group. The novel finding of this study is the association of Thr54 allele with insulin resistance, leptin, and adiponectin levels in morbidly obese patients.