Supplementary Material for: Association between transcription factor 7-like 2 C/T polymorphism and diabetic retinopathy risk: a meta-analysis

Background: Previous studies have suggested a close association between transcription factor 7-like 2 (TCF7L2) polymorphisms and diabetic retinopathy (DR) susceptibility. However, the published results were inconsistent. This meta-analysis was conducted to review and examine the relationship between TCF7L2 rs7903146 C/T polymorphism and DR risk.
Materials and methods: Online databases were searched and the related studies were identified in this meta-analysis. Odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were calculated to examine the statistical power. Moreover, heterogeneity test, sensitivity accumulative analysis and publication bias were conducted to measure the statistical effect.
Result: 6 studies involving 12,982 subjects were included in this meta-analysis to assess the association between rs7903146 C/T polymorphism and DR susceptibility. The synthetic results indicated that the mutation of rs7903146 C/T polymorphism maybe accompany with an increased risk for DR (T vs. C: OR=1.26, 95%CI=1.00-1.60, P=0.05, I2=83.5%; TT vs. CC: OR=1.79 95%CI=1.12-2.86, P=0.02, I2=80.2%; TT vs. CC+CT: OR=1.62, 95%CI=1.38-1.92, P<0.01, I2=32.3%). Moreover, the subgroup analysis also demonstrated an increasing risk for DR with T mutations in Caucasian descendants.
Conclusion: The current evidences meta-analysis suggested that the TCF7L2 rs7903146 C/T polymorphism might be play an important role in DR susceptibility.