Correlation between the serum alkaline phosphatase level and the severity of coronary artery disease.

OBJECTIVE

The serum alkaline phosphatase (ALP) level has shown to be a prognostic factor in myocardial infarction and peripheral vascular disease by its promoting effect on vascular calcification. A few recent studies also showed that elevated ALP levels were associated with mortality and unfavorable prognosis in coronary artery disease (CAD). Herein, we aimed to investigate the correlation between serum ALP levels and the severity of CAD by assessing the Gensini score.

METHODS

A total of 470 patients with stable angina pectoris were evaluated retrospectively.Upon admission, their ALP levels were measured with an automated analyzer by the enzymatic method, and the severity of CAD was documented for each patient according to their Gensini score. Patients with a Gensini score greater than 40 were defined to have an advanced CAD. Serum ALP levels higher than 129 mg/dl in men and higher than 104 mg/dl in women were defined as the elevated ALP groups.

RESULTS

The mean ALP level was 97.3±56.4, ranging from 15 to 485 U/l with 66.0/82.5/106.0 U/l percentile values, and elevated ALP levels were obtained in 79 cases (16.8%). In 70% of the patients (n=329), advanced CAD was diagnosed. The mean Gensini score was 85.6±29.4 in the advanced CAD group and 12.8±15.8 in the remainder of the patients. The advanced CAD group included more men, patients with diabetes mellitus, hypertension, and a reduced left ventricular ejection fraction, and patients with lower levels of high-density lipoprotein cholesterol and higher levels of creatinine, red cell distribution width, and mean platelet volume. ALP levels (105.4±60.7 vs. 78.4±38.7 U/l, P<0.001) and the frequency of patients with elevated ALP levels (22 vs. 5.0%, P<0.001) were significantly higher in the advanced CAD group. Regression analysis showed a significant correlation between increased levels of serum ALP and advanced CAD in univariate (odds ratio 1.015, 95% confidence interval 1.008-1.1291, P<0.001) and multivariate analyses (odds ratio 1.013, 95% confidence interval 1.003-1.023, P=0.01).

CONCLUSIONS

Elevated ALP levels are associated with higher Gensini scores and a more severe form of CAD.