Association of MTHFR C677T polymorphism and risk of cerebrovascular disease in Chinese population: an updated meta-analysis

A variety of epidemiological studies have evaluated the association between methylenetetrahydrofolate reductase (MTHFR) gene C677T polymorphism and cerebrovascular disease, but the results were inconsistent. The present meta-analysis was therefore performed to investigate the relationship between C677T polymorphism and cerebrovascular disease in Chinese population. Systematically searching for related studies from PubMed, Embase, Web of Science, CBMdisc and CNKI databases up to 20 September 2013 and manual searching of the reference lists of identified articles was performed. Information was extracted to calculate for the additive, dominant, and recessive models using the pooled odds ratios (ORs) along with 95 % confidence intervals (CIs), using Review Manager 5.0, STATA 11.0 and SPSS 17. Logistic regression, fixed or random effects model, subgroup analysis, sensitivity analysis, meta-regression analysis and publication bias were conducted to improve the comprehensive analysis. A total of 68 case-control studies containing 7,990 cases and 6,941 controls were included in the final meta-analysis. Evidence of significant association between C677T polymorphism and risk of cerebrovascular disease was found in all three genetic models (additive model OR 1.472, 95 % CI 1.368-1.585, P (L) < 0.001 (CT vs. CC); OR 1.819, 95 % CI 1.666-1.985, P (L) < 0.001 (TT vs. CC); dominant model OR 1.77, 95 % CI 1.57-1.98, p < 0.00001; and recessive model OR 1.54, 95 % CI 1.39-1.71, p < 0.00001, respectively) based on the overall population. In addition, the results were verified by the subgroup analysis and sensitivity analysis. The present meta-analysis suggests that MTHFR gene C677T polymorphism is significantly associated with increased risk of cerebrovascular disease. TT genotype may act as an independent risk factor for cerebrovascular disease in Chinese population.