The G3057A LEPR polymorphism is associated with obesity in Tunisian women.

ABSTRACT

OBJECTIVES: The aim of this study was to evaluate the effect of the G3057A (rs62589000) LEPR polymorphism on obesity risk and plasma leptin, insulin, and lipid levels in a sample of the Tunisian population. DESIGN AND METHODS: Three hundred and ninety-three obese patients and 317 controls participated in this study. The G3057A genotype was determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. RESULTS: In the entire study sample, no significant differences in genotype frequencies were observed between obese patients and controls. However, stratified analysis by gender revealed a quantitative increase in the variant allele (33.3% vs. 25.8%; χ(2)=4.90, p=0.026) in obese women (but not men) compared to controls. When a dominant model of inheritance was assumed, the GA+AA genotypes were more prevalent in these obese female patients than in controls (58.3% vs. 47.8%; χ(2)=4.08, p=0.044). Unconditional logistic regression showed that in women only, obesity risk was significantly higher for homozygotes for the variant allele (OR=2.73, 95% CI 1.03-7.21) and for carriers of GA+AA genotypes (OR=1.53, 95% CI 1.01-2.31) compared with homozygotes for the normal allele. The association between the G3057A LEPR variant and obesity remained statistically significant even after adjustment for age. No relationship was found between the G3057A LEPR polymorphism and leptin and insulin levels. Additionally, this LEPR gene variant had no effect on plasma lipid concentrations. CONCLUSION: There is evidence in this study that the G3057A LEPR polymorphism is associated with obesity in Tunisian women.