Objective: Many studies have investigated the role of 5,10-methylenetetrahydrofolate reductase gene (MTHFR) C677T/A1298C polymorphisms in essential hypertension (EH), but results are inconclusive. The purpose of this meta-analysis was to clarify the effects of MTHFR C677T/A1298C polymorphisms on the risk of EH.
Methods: Electronic databases were searched to identify relevant studies published until January 2014. Data were extracted by two independent authors. Odds ratios (ORs) with 95%confidence intervals (CIs) were used to assess the association between MTHFR C677T/A1298C polymorphisms and the risk of EH using random effect models or fixed effect models. Finally,30 studies with 5207 cases and 5383 controls were included for C677T polymorphism and 6 studies with 1009 cases and 994 controls were included for A1298C polymorphism.
Results: Meta-analysis results indicated that MTHFR C677T polymorphism contributed to an increased risk of EH (for T vs. C: OR=1.30, 95%CI=1.18–1.43; for TT+CT vs. CC: OR=1.34, 95%CI=1.24–1.46; for TT vs. CC: OR=1.62, 95%CI=1.32–1.99; for TT vs. CT+CC: OR=1.41, 95%CI=1.26–1.59). However, no significant association was detected between MTHFR A1298C polymorphism and the risk of EH.
Conclusion: This meta-analysis supports that MTHFR C677T polymorphism plays a role in developing EH. MTHFR A1298C polymorphism may not be associated with an increased risk of EH. Further large and well-designed studies are warranted to confirm these findings.