AGT M235T polymorphisms and ischemic stroke risk: a meta-analysis.

Recently, the association between AGT M235T polymorphism and ischemic stroke (IS) has attracted widespread attention, and many investigations have been performed. However, the results were inconsistent. Therefore, we performed a meta-analysis to further evaluate the association between M235T and IS. All of the relevant studies were identified from PubMed, EMBASE, Chinese National Knowledge Infrastructure database (CNKI), Chinese Biological Medical Literature database (CBM), Chinese Wanfang and Chongqing VIP database up to January 2013. Statistical analyses were conducted with STATA software version 11.1. Odds ratios with 95% confidence interval were applied to evaluate the strength of the association. We performed the cumulative meta-analysis to assess the tendency of pooled OR over time. Heterogeneity was evaluated by Q-test and the I(2) statistic. The funnel plots and Egger's regression test were used to assess the publication bias. A significant association between AGT M235T polymorphism and IS was found under the dominant model (OR=1.368, 95% CI=1.070-1.749), recessive model (OR=1.66, 95% CI=1.310-2.103), over-dominant model (OR=1.285, 95% CI=1.085-1.523), co-dominant model (OR=1.574, 95% CI=1.276-1.942) and allele model (OR=1.447, 95% CI=1.207-1.735). Besides the Caucasian and the population-based controls, significant association could be found in the subgroup analysis of Asian and hospital-based controls. Results from cumulative analysis showed a tendency of significant association of this polymorphism with IS. However, the opposite trend was observed among Caucasians. Results from our meta-analysis indicated that the AGT M235T polymorphism might be a risk factor for IS among Asians, but not for Caucasians. More studies are required to further confirm our findings.