Association between angiotensin-converting enzyme insertion/deletion polymorphism and migraine: a meta-analysis

Background: Many studies investigated the association between angiotensin-converting enzyme (ACE) insertion/deletion (I/D) polymorphism and migraine, with controversial results. Thus, we performed a meta-analysis to better evaluate the correlation of this polymorphism and migraine. Methods: We retrieved studies published up to September 2014 about the ACE gene polymorphism and migraine from electronic database. Pooled odds ratios (ORs) with 95% confidence interval (CI) were calculated to examine the strength of association between the ACE I/D polymorphism and migraine, using random-effects models. Results: We identified 14 separate studies, in which 7334 migraineurs and 22 990 healthy controls were eligible for the meta-analysis. The results showed no relationship between the ACE I/D polymorphism and any migraine. Stratification revealed a protective effect in the Turkish population against migraine with aura for the II genotype model (II vs. DD: pooled OR = 0.366, 95% CI = 0.137–0.980; II vs. DI + DD: pooled OR = 0.370, 95% CI = 0.145–0.945). Similar results were obtained for Turkish people with migraine without aura (II vs. DD: pooled OR = 0.386; 95% CI = 0.166–0.900; II vs. DI + DD: pooled OR = 0.347; 95% CI = 0.156–0.773). Conclusions: The data suggest that the ACE II genotype could exert a protective effect against migraine with aura and without aura at least in the Turkish population.