Association of TCF7L2 gene polymorphisms with type 2 diabetes mellitus in Han Chinese population: A meta-analysis

Abstract

Variants of transcription factor 7-like 2 (TCF7L2) gene have been reported to be associated with type 2 diabetes mellitus (T2DM), but the available data on this relationship are inconsistent in Han Chinese populations. A meta-analysis was performed to quantitatively analyze the association of TCF7L2 gene polymorphisms with T2DM using previous case–control studies in Chinese Han populations. Several electronic databases were searched for relevant articles up to May 2012. After data collection and gene loci selection, a meta-analysis was performed to assess heterogeneity, combine results and evaluate variations. Publication bias was examined by the Egger's linear regression test. Hardy–Weinberg equilibrium (HWE) test and by omitting one study at a time were employed for the sensitivity analysis. Eighteen studies from sixteen eligible papers were included in the meta-analysis. Ten eligible studies were analyzed for rs7903146, and eight were analyzed for rs290487. We found that the rs7903146 T allele was associated with an increased risk for T2DM under a dominant model, a co-dominant model and an allele contrast model, with an OR of 1.54 (1.32, 1.79), an OR of 1.53 (1.31, 1.79) and an OR of 1.52 (1.31, 1.76), respectively. The rs290487 C allele showed no significant overall association with T2DM, yielding ORs of 1.08 (0.88, 1.32) under a dominant model, with strong evidence of heterogeneity. Similar results were also obtained in other genetic models. Sensitivity analysis confirmed the reliability and stability of this meta-analysis. The accumulated evidence suggested that the rs7903146 T allele was associated with an increased risk for T2DM, but the rs290487 C allele is not associated with T2DM in the Chinese Han population. More well-designed large studies are required for the validation of this association.