Meta-analysis of association studies between five candidate genes and type 2 diabetes in Chinese Han population

The multiple small-scale association studies of candidate genes for type 2 diabetes mellitus in the Chinese Han population have shown inconsistent results. Here, we performed a meta-analysis to evaluate the contribution of five candidate genes to the pathogenesis of type 2 diabetes in the Chinese Han population. We searched for relevant published papers and used STATA v.11.0 to perform a meta-analysis on six single-nucleotide polymorphisms in five genes-ADIPOQ-rs2241766 (SNP45) and -rs1501299 (SNP276), ADRB3-rs4994 (Trp64Arg), CAPN10-rs3792267 (SNP43), ENPP1-rs1044498 (K121Q), and PPARGC1A-rs8192678 (Gly482Ser)-in the Chinese Han population under an additive genetic model. The pooled odds ratios (95% confidence intervals and P-values) were 0.71 (0.60-0.83; P < 0.001) for ADIPOQ-rs2241766, 0.79 (0.64-0.97; P = 0.027) for ADIPOQ-rs1501299, 1.27 (1.07-1.51; P = 0.006) for ADRB3-rs4994, 0.79 (0.57-1.10; P = 0.163) for CAPN10-rs3792267, 1.41 (1.13-1.76; P = 0.003) for ENPP1-rs1044498, and 1.54 (1.34-1.81; P < 0.001) for PPARGC1A-rs8192678. There was high heterogeneity for ADIPOQ-rs2241766, ADIPOQ-rs1501299, and CAPN10-rs3792267 (I (2) = 74.9, 69.4, and 75.8%, respectively), but not for ADRB3-rs4994, ENPP1-rs1044498, and PPARGC1A-rs8192678 (I (2) = 0.0, 43.4, and 23.3%, respectively). Under an additive genetic model, the C allele of ADRB3-rs4994, the C allele of ENPP1-rs1044498, and the A allele of PPARGC1A-rs8192678 increase the risk of type 2 diabetes in the Chinese Han population.