Plasma alkaline phosphatase and survival in diabetic patients with acute myocardial infarction.

BACKGROUND Alkaline phosphatase (ALP) removes phosphate groups from many types of molecules. The aim of the present research was to study the relation between plasma ALP and survival in diabetic patients with myocardial infarction. METHODS Retrospective study: from 954 admissions (15 months period) in a coronary care unit, we selected 200 admissions corresponding to 195 patients with myocardial infarction and diabetes mellitus. Survival after no less than 48 months, and up to 61 months, after the myocardial infarction episode, was under study, in association with ALP levels. RESULTS A relatively weak but significant correlation was seen between the peak plasma cardiac troponin I and ALP levels (r: 0.21, significance level: 0.003). Using the median value for ALP as cut-off (74 IU/L), plasma creatinine was significantly higher in patients with higher values for ALP. Patients with elevated ALP had decreased survival in Kaplan-Meier analysis (significance level in log-rank test: 0.032). This finding was noted for male patients (significance level in log-rank test: 0.035), but not for female patients (significance level in log-rank test: 0.497). CONCLUSIONS Elevated ALP acts as a prognostic indicator of decreased survival in diabetic patients with acute myocardial infarction, possibly in association to decreased renal function. This finding is limited to male patients, pointing to a possible different role for phosphatase activity in cardiovascular disease in male and female diabetic patients.