Effects of rs1799983 and rs1800779 polymorphisms in the endothelial nitric oxide synthase gene on migraine susceptibility with and without aura: a meta-analysis

Polymorphisms (rs1799983 and rs1800779) in the endothelial nitric oxide synthase (eNOS) gene have been reported to be associated with migraine susceptibility; however, published findings have been never reached a consensus. To obtain a more accurate estimate of the effects of eNOS rs1799983 and rs1800779 polymorphisms on migraine susceptibility, we performed this meta-analysis. A comprehensive online search of PubMed, Ovid, EBSCO, the Cochrane Library, the Web of Science, the China National Knowledge Infrastructure, Wanfang, and Chinese Biomedicine databases. All publications published before February 29, 2016, were selected regardless of whether the article was published in Chinese or English. Ten eligible studies comprised 1819 patients with migraine and 3144 controls. Pooled odds ratios (ORs) with corresponding 95% confidence intervals (CIs) were calculated to evaluate associations using fixed or random-effects models. Our results showed that rs1799983 was associated with susceptibility to migraine with aura (MA) in the genetic recessive (TT versus GT+GG: OR=1.41, 95% CI=1.021.96) and co-dominant (TT versus GG: OR=1.50, 95% CI=1.04-2.15) models. However, the robustness of the results may be weak. Moreover, no significant associations were found between the rs1799983 polymorphism and migraine susceptibility in cases of migraine without aura (MO) or between the rs1800779 polymorphism and migraine susceptibility in cases of MA and MO. Thus, the current meta-analysis suggested that the rs1799983 polymorphism in eNOS is associated with MA susceptibility. Further studies with larger sample sizes are needed to evaluate these associations in patients of different ethnicities.