A study of patients seeking care at an inner-city clinic showed that higher levels of alkaline phosphatase and phosphate are associated with increased mortality.
Higher alkaline phosphate levels also increased the risk of all-cause hospitalization and hospitalization due to cardiovascular disease (CVD), infection, and fracture, researchers reported in the Clinical Journal of the American Society of Nephrology (2010;5:1064-1071).
Matthew Abramowitz, MD, of Albert Einstein College of Medicine in Bronx, N.Y., and colleagues studied 10,743 patients who had serum alkaline phosphatase and phosphate levels measured between 2000 and 2002. The patients had an estimated glomerular filtration rate of 60 mL/min/1.73 m2 or higher. The study population had a mean age of 51 years and 64% of subjects were women, 22% were white, 26% were non-Hispanic black, and 16% were Hispanic.
Compared with patients in the lowest quartile of alkaline phosphatase (66 U/L or less), those in the highest quartile (104 U/L or greater) had a 65% increased risk of mortality, a 14% increased of all-cause hospitalization, and a 28%, 53%, and 63% increased risk of hospitalization due to CVD, infection, and fracture, respectively, after adjusting for potential confounders.
In addition, compared with patients in the lowest quartile of serum phosphate (3.0 mg/dL or less), those in the highest quartile (3.8 mg/dL or greater) had a 29% increased mortality risk and a 14% increased risk of CVD-related hospitalization, but they did not have an increased risk of hospitalization due to injection or fracture.