Effect of the rs1862513 variant of resistin gene on insulin resistance and resistin levels after two hypocaloric diets with different fat distribution in subjects with obesity.

Abstract

Polymorphisms of a single nucleotide in resistin gene (RETN) have been associated with insulin resistance. We decide to investigate the role of this polymorphism on insulin resistance and resistin levels after two hypocaloric diets. A sample of 361 obese non-diabetic Caucasian was enrolled. Biochemical evaluation and anthropometric data were measured at the start of the trial and repeated after 3 months of both diets (Diet P, Polyunsaturated vs. diet M, Monounsaturated). With both diets and in both genotype groups, BMI, weight, fat mass, waist circumference, systolic blood pressure, and diastolic blood pressure decreased. After diet P, insulin levels (GG vs. GC+CC genotypes) (-1.2±3.8 UI/L vs. -0.7±2.1 UI/L; p<0.05), HOMA-IR (-0.6±1.0 units vs. -0.4±0.9 units; p<0.05), total cholesterol (-10.5±20.1 mg/dl vs. -6.1±15.1 mg/dl; p<0.05) and LDL-total cholesterol (-8.6±10.1 mg/dl vs. -2.2±9.1 mg/dl; p<0.05) decreased in subjects with GG genotype. After diet M, insulin levels (-1.8±2.1 UI/L vs. -0.6±3.0 UI/L: p>0.05), HOMA-IR (-0.5±1.0 units vs. -0.3±1.1 units: p>0.05), total cholesterol (-9.5±13.1 mg/dl vs. -4.4±8.1 mg/dl; p<0.05) and LDL-total cholesterol (-8.1±6.1 mg/dl vs. -2.9±9.1 mg/dl; p<0.05) decreased, too. We suggest that GG genotype of RETN rs1862513 could be a predictor of the reduction of HOMA-IR, insulin, and LDL cholesterol secondary to two hypocaloric diet in obese subjects.