Association between the methylenetetrahydrofolate reductase (MTHFR) gene C677T polymorphism and ischemic stroke in the Chinese population: a meta-analysis.

PURPOSE: The association between the methylenetetrahydrofolate reductase (MTHFR) gene C677T polymorphism and ischemic stroke (IS) has been extensively studied; however, the results from genetic association studies have been inconsistent even in the Chinese population. As far as we know, there was no previous meta-analysis concerning this association in the Chinese population. Therefore, the aim of our meta-analysis was to further evaluate the association in the Chinese population.

METHODS: We collected all of the relevant studies from Pubmed, OVID, Embase, Chinese Wan Fang database, CNKI, Chongqing VIP database and CBM up to August 2014. The available data was analyzed by Stata (version 12.0). We used odds ratios (ORs) and corresponding 95% confidence intervals (CIs) to present the strength of the association. Heterogeneity was evaluated by the Q-test and I(2) statistic. Different genetic models, subgroup analysis, publication bias and sensitivity analysis were used to improve the comprehensive understanding.

RESULTS: The results showed a significant association between the MTHFR gene C677T polymorphism and IS in six genetic models (additive model: OR = 1.34, 95%CI: 1.17 ∼ 1.54, p < 0.001; dominant model: OR = 1.44, 95% CI:1.26 ∼ 1.64, p < 0.001; recessive model: OR = 1.45, 95% CI: 1.15 ∼ 1.83, p = 0.001; heterozygote model: OR = 1.35, 95% CI: 1.18 ∼ 1.55, p < 0.001; homozygote model: OR = 1.80, 95% CI: 1.34 ∼ 2.41, p < 0.001; and allelic model: OR = 1.34, 95% CI: 1.17 ∼ 1.53, p < 0.001) based on the overall population, as well as subgroup analysis. In addition, the similar results were obtained in the sensitivity analysis based on studies with the high quality.

CONCLUSIONS: This meta-analysis presented a significant association between the MTHFR gene C677T polymorphism and IS, the T allele might be a risk factor for IS in the Chinese population.