Impact of serum alkaline phosphatase level on the pathophysiologic mechanism of contrast-induced nephropathy

Background: Contrast-induced nephropathy (CIN) accounts for 10% of all causes of hospital-acquired renal failure. It leads to a prolonged in-hospital stay, and represents a powerful predictor of poor early and late outcomes. More than half of cases are observed after cardiovascular procedures. Aim: To determine the predictive value of the serum alkaline phosphatase (ALP) level in the development of CIN, something which has not been assessed before. Methods: We prospectively evaluated a total of 430 patients with acute coronary syndrome. Patients were classified according to the development of CIN and both groups were compared statistically according to clinical, laboratory and demographic features, including the serum ALP level. Results: CIN was observed in 20.5% of patients. Advanced age, male gender, elevated creatinine, uric acid and phosphate levels, and low glomerular filtration rate were correlated with the development of CIN. Correlation analysis also showed a significant association between the ALP level and the development of CIN (126.1 +/- 144.9 vs. 97.2 +/- 46.9, p = 0.004). Univariate regression analysis also showed the impact of ALP on the development of CIN (OR 1.004, 95% CI 1.001-1.007, p = 0.02). Conclusions: Our outcomes indicate a possible active role of ALP in the mechanism of CIN. An elevated ALP level may predict the development of CIN.