MTHFR 677 T variant contributes to diabetic nephropathy risk in Caucasian individuals with type 2 diabetes: A meta-analysis

Abstract Objective Previous studies regarding the association between 5,10-methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and diabetic nephropathy (DN) risk in Caucasian individuals with type 2 diabetes reported conflicting results. To derive a more precise estimation of this association, a meta-analysis was performed. Materials/Methods Odds ratios (ORs) with corresponding 95% confidence intervals (95% CIs) were pooled to assess the association between MTHFR C677T polymorphism and DN risk. Finally, 10 case–control studies with a total of 1590 DN cases and 1555 type 2 diabetic controls without DN were included. Results Overall, there was an association between MTHFR C677T polymorphism and increased risk of DN under four comparison models (OR T vs . C  = 1.50, 95% CI 1.07–2.02, P = 0.02; OR TT vs . CC  = 2.09, 95% CI 1.07–4.08, P = 0.03; OR TT vs . TC  +  CC  = 1.70, 95% CI 1.10–2.63, P = 0.017; OR TC  +  TT vs . CC  = 1.85, 95% CI 1.19–2.88, P = 0.006). Sensitivity analysis suggested exclusion of any single study did not materially alter the overall pooled ORs above. Conclusions This meta-analysis supports that there is an association between MTHFR C677T polymorphism and DN risk, and MTHFR 677 T variant contributes to increased risk of DN in Caucasian individuals with type 2 diabetes.