[Association of leptin gene-2548 G/A polymorphism with obesity: a meta-analysis]

To examine the association between a common single nucleotide polymorphism identified in the 5' untranslated region of leptin gene (LEP-2548 G/A SNP) and obesity.

Meta-analysis of published studies, included if subjects were genotyped at polymorphism LEP-2548 G/A and both obese and nonobese subjects were selected, based on a reported cutoff BMI limit. Meta-analysis of the total and subgroup populations was conducted using dominant and recessive models, and OR and 95% CI were calculated in the fixed-effect model. I2 statistic was calculated to examine heterogeneity, and publication bias was evaluated by Egger test.

After testing each control group for Hardy-Woinberg equilibrium, the final selection enrolled 11 studies, including 5210 subjects (2541 obesity subjects and 2669 healthy). In the combined analysis of all eligible studies, none significant association was identified between LEP-2548 G/A SNP and obesity either in dominant model or the recessive one with pooled odds ratios 1.14 (95% CI 0.98-1.31, P = 0.08) and 1.03 (95% CI 0.85-1.25, P = 0.76). However, subgroup analysis found a significant association of GG homozygote in American population [OR = 1.53 (95% CI 1.17-2.00), P = 0.002]. No significant evidence was found in other populations.

This first metaanalysis of data from published studies did not detect any association between the polymorphism of LEP-2548 G/A and risk of obesity in overall population. Nevertheless, the presence of the GG genotype in the gene appears to be a significant risk factor for obesity in American.