The association between leptin receptor gene polymorphisms and type 2 diabetes mellitus: A systematic review and meta-analysis

Background: Several case-control studies have demonstrated a relationship between leptin receptor (LEPR) gene polymorphism and type 2 diabetes mellitus (T2DM) risk, though the results have not always been consistent among diverse populations. This meta-analysis was designed to assess a more accurate association between LEPR polymorphism and T2DM. Methods: Eight electronic databases were consulted and researchers searched for Chinese and English peer-reviewed articles, published between 2000 and 2015, that referred to the association between LEPR polymorphism and T2DM. Pooled odds ratios (OR) with a 95% confidence interval (CI) were calculated in allele contrast, recessive, dominant and additive genetic models to assess this association. Results: Four repeatedly reviewed polymorphisms, taken from 22 studies on Arg109Lys, Asn656Lys, Gln223Arg and Pro1019Pro with 31,260 controls and 25,560 cases, were included in the meta-analysis model. The meta-result demonstrated that only the Pro1019Pro polymorphism was substantially associated with T2DM risk-G vs. A: OR with 95% CI 0.58 (0.43-0.79), Z = 3.51, p = 0.0005; GG vs. AG + AA: 0.57 (0.42-0.77), Z = 3.66, p = 0.0002; GG + AG vs. AA: 0.55 (0.37-0.81), Z = 3.01, p = 0.003; GG vs. AA: 0.51 (0.37-0.69), Z = 4.24, p < 0.001. Conclusions: Our meta-analysis suggested a significant association between the LEPR Pro1019Pro polymorphism and T2DM risk. Thus, targeted healthcare should be strengthened with regard to this gene carrier in order to prevent T2DM. (C) 2016 Elsevier Ireland Ltd. All rights reserved.