MPO and diabetes mellitus: Hypertension, diabetes mellitus, and age did not affect the prognostic value of MPO for clinical outcomes, whereas female gender and smoking status have a strong influence on the prognostic value of MPO in terms of mortality and recurrent MI (metaregression coefficient -8.616: 95% CI -14.59 to -2.633, P = 0.0048 and 4.88: 95% CI 0.756 to 9.0133, P = 0.0204, respectively).