Alkaline phosphatase and prognosis in patients with diabetes mellitus and ischemic heart disease.

BACKGROUND

The association between alkaline phosphatase (ALP) and mortality in patients with diabetes mellitus (DM) and ischemic heart disease (IHD) remains poorly investigated.

METHODS

The study included 1426 patients with DM and IHD who underwent percutaneous coronary intervention. Patients were divided in groups according to tertiles of ALP activity: a group with ALP activity in 1st tertile (ALP activity: 20.8-65.0 U/L; n = 478), a group with ALP activity in 2nd tertile (ALP activity: 65.1-87.0 U/L; n = 473) and a group with ALP activity in 3rd tertile (ALP activity: 87.1-1520 U/L; n = 475). The primary endpoint was 3-year all-cause mortality.

RESULTS

At 3 years, all-cause deaths occurred in 182 patients: 50 deaths (12.4%) in patients of 1st tertile, 47 deaths (11.7%) in patients of 2nd tertile and 85 deaths (20.8%) in patients of 3rd tertile of ALP activity (adjusted hazard ratio [HR] = 1.20, 95% confidence interval [CI] 1.02 to 1.42, P = 0.031); cardiac deaths occurred in 110 patients: 28 deaths (7.0%) in patients of 1st tertile, 30 deaths (7.6%) in patients of 2nd tertile and 52 deaths (12.7%) in patients of 3rd tertile of ALP activity (adjusted HR = 1.27 [1.04-1.56], P = 0.021, with both risk estimates calculated for unit increment in the log scale of ALP activity). The C-statistic of the multivariable model with baseline data without and with ALP was 0.787 [0.750-0.818] and 0.804 [0.757-0.851], (P = 0.575) for all-cause mortality and 0.832 [0.798-0.864] and 0.876 [0.833-0.918], (P = 0.115) for cardiac mortality.

CONCLUSIONS

In patients with DM and IHD, elevated ALP activity was associated with increased risk of 3-year mortality.