Melatonin receptor 1B gene polymorphism rs10830963 and gestational diabetes mellitus among a Chinese population - a meta-analysis of association studies.

INTRODUCTION: Studies have been conducted to investigate the association between rs10830963 of MTNR1B and the risk of gestational diabetes mellitus (GDM), but with inconclusive results. We aimed to clarify these controversies, especially with regard to the association in the Chinese population. MATERIAL AND METHODS: A systemic literature reference search inclusive to August 12, 2016 yielded 35 articles, from which 11 studies met the inclusion criteria for the final meta-analysis, including 3889 patients with GDM and 6708 controls. RESULTS: We found statistically significant associations between rs10830963 and GDM using odds ratios (ORs) and 95% confidence intervals (CIs) [GG genotype vs. CC genotype: OR = 1.70, 95% CI: 1.38-2.10; G allele vs C allele: OR = 1.27, 95% CI: 1.20-1.36; GG+CG vs. CC (dominant model): OR = 1.31, 95% CI: 1.20-1.44; GG vs CG+CC (recessive model): OR = 1.41, 95% CI: 1.26-1.58]. In subgroup analyses stratified by ethnicity, we also observed rs10830963 to be associated with significantly increased risk of GDM in all genetic models in the Chinese population. CONCLUSIONS: Our meta-analysis indicated that the rs10830963 polymorphism might serve as a risk factor of GDM in the Chinese population.