Association between the Matrix Metalloproteinase-9 rs3918242 Polymorphism and Ischemic Stroke Susceptibility: A Meta-Analysis

Background In recent years, dozens of case-control studies showed that matrix metalloproteinase (MMP)-9 rs3918242 variants were associated with ischemic stroke (IS) susceptibility. However, the conclusions of case-control studies that evaluated the relationship between MMP-9 rs3918242 variants and the risk of IS were still equivocal. Herein, we conducted a comprehensive meta-analysis to investigate the association between MMP-9 rs3918242 variants and the risk of IS. Methods We searched 5 databases (PubMed, EMBASE, Google Scholar, Web of Science, and Chinese Biomedical Literature Database) to identify the eligible studies up to October of 2016. The pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to evaluate the association of MMP-9 rs3918242 variants with IS susceptibility under the allelic model (T versus C) and the dominant model (TT + CT versus CC). Results A total of 14 studies with 3233 cases and 3123 controls were included in this meta-analysis. Our meta-analysis indicated that MMP-9 rs3918242 variants were associated with significantly increased risk of IS in overall populations (T versus C: OR = 1.43, 95% CI = 1.20-1.71, P