Association of MMP-9 gene polymorphism and ischemic stroke: evidence from a case-control study to a meta-analysis

Matrix metalloproteinase 9 (MMP-9) plays an important role in the pathophysiology of inflammation. Several studies have investigated the association between MMP-9 -1562C/T polymorphism and risk of ischemic stroke (IS) where inflammatory process is involved, but the results were inconsistent. Therefore, we first conducted a case-control study to investigate the potential association, and then performed a meta-analysis to further address this issue. A total of 386 patients with IS and 386 unrelated controls were included in the study. Genotyping was performed using polymerase chain reaction-ligation detection reaction method. A meta-analysis was conducted by combining our data with previous relevant studies. In our case-control study, no significant association was found between MMP-9 -1562C/T and IS risk (P > 0.05). However, when combined with previous studies, the significant association of MMP-9 -1562C/T with IS risk was observed under allelic (OR = 1.28, 95% CI = 1.06-1.55, P = 0.01), homozygous (OR = 2.08, 95% CI = 1.49-2.90, P < 0.01), dominant (OR = 1.26, 95% CI = 1.03-1.53, P = 0.02) and recessive model (OR = 1.54, 95% CI = 1.08-2.20, P = 0.02). Moreover, subgroup analysis by ethnicity detected a significant association in Asian population, but not Caucasian population. In summary, evidence from a case-control study to a meta-analysis indicates that MMP-9 -1562C/T polymorphism likely serves as a potential risk factor for developing IS, especially in Asian population.