Relationship between variants of the leptin gene and obesity and metabolic biomarkers in Brazilian individuals.

OBJECTIVE The relationship between variants of the leptin gene (LEP) and obesity and metabolic biomarkers was investigated in Brazilian individuals. SUBJECTS AND METHODS One-hundred-ten obese (BMI > 30 kg/m(2)) and 100 non-obese individuals (145 women and 65 men, aged 49 +/- 14 years) were randomly selected. Plasma leptin, glycemia, serum lipid measurements and LEP -2548G>A and 3'HVR polymorphisms were analyzed. RESULTS The LEP -2548GG genotype was associated with a 2.2% and 2.0% increase in BMI (p = 0.009) and plasma leptin (p = 0.031), respectively. 3'HVR I/II (classes I/I+I/II) genotypes contributed with 1.8% of BMI values (p = 0.046). LEP I/G combined genotypes (I/IGG, I/IGA and I/IIGG) were associated with obesity, and increased BMI, waist circumference, leptin and triglycerides (p < 0.05). These relationships were found in women (p < 0.05) but not in men. LEP I/G combined genotypes were not associated with hypertension, hyperglycemia, dyslipidemia and coronary artery disease. CONCLUSIONS LEP I/G combined genotypes are associated with obesity-related metabolic biomarkers and phenotype in a gender-dependent manner.