Association between Leptin G2548A and Leptin Receptor Q223R Polymorphisms with Type 2 Diabetes in an Iranian Population.

The leptin (LEP G2548A) and leptin receptor (LEPR Q223R) gene polymorphisms have been variably associated with type 2 diabetes (T2D) in different populations. In this study we hypothesized that these variants might be associated with T2D and related metabolic traits in an Iranian population. The LEP G2548A and LEPR Q223R genotypes were determined by PCR-RFLP in 378 normoglycemic controls and 154 T2D patients. Bonferroni correction was applied for the correction of multiple testing. The A allele of the LEP G2548A polymorphism was more prevalent in females of the T2D group than the controls (p = 0.009). In a recessive model (GG+GA vs. AA), the frequency of the AA genotype was higher in female patients compared to normoglycemic subjects 134.9% vs. 19.3%, OR 2.60 (1.27-5.31), p = 0.0091. Multivariate logistic regression analysis also showed that the AA genotype of the LEP G2548A polymorphism is an independent risk factor for T2D in females. No significant association was found between the allele and genotype frequencies of the LEPR Q223R variant with T2D in female and male groups. In addition, no significant difference in anthropometrical and biochemical parameters was observed between the genotypes of LEP and LEPR variants in gender-specific groups in both non-diabetic and diabetic subjects. Our results suggest that the LEP G2548A polymorphisms might associate with T2D among Iranian female subjects, whereas the LEPR Q223R variant is not associated with T2D and its related metabolic traits in this population.