Association between a functional polymorphism rs10830963 in melatonin receptor 1B and risk of gestational diabetes mellitus: an updated meta-analysis

The melatonin receptor 1B ( MTNR1B ) as a candidate gene for gestational diabetes mellitus (GDM) on the basis of its association with T2DM, β-cells function and fasting plasma glucose (FPG) level. Many studies have investigated the association between MTNR1B polymorphism rs10830963 C>G and GDM risk, but the conclusion is inconsistent. PubMed, Google Scholar and CNKI databases were searched to identify eligible studies. Pooled OR with corresponding 95% CI was used to estimate the strength of the association between rs10830963 and GDM risk using a fixed- or random-effect model. 12 eligible studies with a number of 4,782 GDM patients and 5,605 controls were included in this meta-analysis. Results indicated that the variant G allele of rs10830963 polymorphism was significantly associated with an increased risk of GDM (CG vs. CC: OR=1.23, 95% CI = 1.12–1.34, P heterogeneity = 0.23; GG vs. CC: OR=1.74, 95% CI =1.41–2.15, P heterogeneity = 0.002). In the stratified analysis by ethnicity, similar results were found in Asians (CG vs. CC: OR=1.15, 95% CI = 1.04–1.28, P heterogeneity = 0.74; GG VS. CC: OR=1.48, 95% CI =1.23–1.78, P heterogeneity = 0.08) and in Caucasians (CG vs. CC: OR=1.49, 95% CI =1.25–1.77, Pheterogeneity = 0.28; GG vs. CC: OR=2.68, 95% CI =2.03–3.54, P heterogeneity = 0.58).