The basic characteristics of the included studies for rs7903146.

<p>Abbreviations: HWE, Hardy–Weinberg equilibrium; Yes, the genotype distribution meet the HWE in control group; No, the genotype distribution not meet HWE in control group; community-based and hospital staff : subjects who were enrolled from community and hospital staff; Hospital-based: subjects who were enrolled from health check conducted in hospital; N/D: not description; *: P>0.05; **: P<0.05.</p

Forest plot of the association between rs12255372G/T polymorphism and T2DM risk (subgroup analyses for the southern China: T vs. G).

<p>n indicates the total number of T allele, and N indicates the total number of T allele plus G allele.</p

Forest plot of the association between rs12255372G/T polymorphism and T2DM risk (overall meta-analysis T vs. G).

<p>n indicates the total number of T allele, and N indicates the total number of T allele plus G allele.</p

Forest plot of the association between rs12255372G/T polymorphism and T2DM risk (subgroup analyses for the HWE in the control groups: T vs. G).

<p>n indicates the total number of T allele, and N indicates the total number of T allele plus G allele.</p

The Association between Gene Polymorphism of TCF7L2 and Type 2 Diabetes in Chinese Han Population: A Meta-Analysis

<div><p>In recent years, it has been widely accepted that transcription factor 7-like 2 (TCF7L2) is associated with type 2 diabetes mellitus (T2DM) in multiple ethnic groups, especially its single nucleotide polymorphisms of rs7903146C/T, rs12255372G/T and rs290487T/C. However, the results previously obtained in Chinese Han population are often inconsistent. For clearing this issue, herein we performed meta-analysis based on the reports that can be found to assess the association. In the meta-analysis, Odds ratio (<i>OR</i>) and 95% confidence interval (95% <i>CI</i>) were calculated with random-effect model or fixed-effect model based on the heterogeneity analysis. The quality of included studies was evaluated by using the Newcastle-Ottawa Scale. The sensitivity analysis was used to confirm the reliability and stability of the meta-analysis. In total, 20 case-control studies with 9122 cases of T2DM and 8017 controls were included. Among these case-control studies, we selected 13 ones on rs7903146 C/T, 5 ones on rs12255372 G/T, 8 ones on rs290487 T/C. The results indicated that rs7903146C/T polymorphism was significantly associated with T2DM (T vs. C, <i>OR = </i>1.73, 95% <i>CI = </i>1.39–2.16). There was no evidence that rs12255372G/T and rs290487T/C polymorphisms increased T2DM risk (T vs. G, <i>OR = </i>1.77, 95% <i>CI = </i>0.88–3.56; C vs. T, <i>OR</i> = 1.08, 95% <i>CI = </i>0.93–1.25). Subgroup analysis of different regions proved the relationship between rs7903146C/T polymorphism and T2DM risk in both the northern and the southern China. The association of rs290487 with T2DM was affected by body mass index, whereas the association of rs7903146 and rs290487 with T2DM was influenced neither by age nor by sex. In conclusion, this study indicated that the rs7903146C/T polymorphism of the TCF7L2 gene had a significant effect on T2DM risk in Chinese Han population, with rs12255372G/T and rs290487T/C polymorphisms showing no significant effect.</p> </div

Quality assessment for all the included studies.

<p>Zhang¹ : Yong Zhang; Zhang² : Ying Zhang.</p

Funnel plots analysis to detect publication bias (T vs. C of rs7903146C/T polymorphism).

<p>Each point represents an independent study for the indicated association.Tables.</p

Flow for the selection of eligible studies.

<p>Flow for the selection of eligible studies.</p

Forest plot of the association between rs7903146C/T polymorphism and T2DM risk (subgroup analyses for the southern: T vs. C).

<p>n indicates the total number of T allele, and N indicates the total number of T allele plus C allele.</p

Forest plot of the association between rs12255372G/T polymorphism and T2DM risk (sensitivity analysis: T vs. G).

<p>n indicates the total number of T allele, and N indicates the total number of T allele plus G allele.</p