Objectives To determine the association between-1562 C>T polymorphism in the promoter region of matrix metalloproteinase-9 (MMP-9) and coronary artery disease (CAD) risk.

Methods This meta-analysis was on the basis of 26 studies including 12,776 cases and 6,371 controls. The was assessed by the Q-statistic test and the I²-statistic test. Sensitivity analysis was conducted by sequentially omitting any single study and recalculating the ORs and 95% CIs. Funnel plots and Egger’s test were performed to test the potential publication bias. All the data were analysed by using STATA version 12.0.

Results We found that-1562 C>T polymorphism did not contribute to susceptibility to CAD in the overall results (OR_{CC vs. TT}= 0.99, 95% CI = 0.94-1.04, P _{heterogeneity}= 1.000; OR_{CC + CT vs. TT} = 0.99, 95% CI = 0.95-1.04, P _{heterogeneity}= 1.000; OR_{CC vs. CT + TT}= 0.96, 95% CI = 0.92-1.01, P _{heterogeneity}= 0.992; OR_{allele C vs. allele T}= 0.98, 95% CI = 0.95-1.01, P _{heterogeneity}= 1.000; OR_{CT vs. TT}= 0.98, 95% CI = 0.89-1.07, P _{heterogeneity} = 1.000). But the stratified analysis by ethnicity and source of control indicated-1562 C>T polymorphism may be a risk factor for the CAD risk in Asians and hospital populations.

Conclusions Our meta-analysis supported the fact that-1562 C>T polymorphism was not associated with the susceptibility to CAD. Further larger studies are required to confirm our findings.