"This large epidemiologic study shows, for the first time, a consistent and robust association between a high blood level of alkaline phosphatase and cardiovascular death in thousands of dialysis patients across the United States," comments Kamyar Kalantar-Zadeh, MD, of the University of California Los Angeles, one of the study authors. "If the association between alkaline phosphatase and mortality has a causal link, treatment strategies that reduce alkaline phosphatase levels may improve survival in patients with CKD, and probably in many other patients with chronic diseases and active bone disorders."
The researchers analyzed data on nearly 74,000 hemodialysis patients in DaVita dialysis clinics during a three-year period. Laboratory measurements of alkaline phosphatase level measured in a DaVita laboratory center were analyzed as a possible predictor of mortality risk. In dialysis patients, alkaline phosphatase levels are routinely measured to monitor metabolic bone disease, a common complication of CKD.
The results showed that patients with higher alkaline phosphatase levels were at higher risk of death during the three-year follow-up period. After adjustment for a wide range of other risk factors, patients with alkaline phosphatase levels above the upper limit of normal (>120 IU/L) had a 25 percent increase in mortality rate.
The link between alkaline phosphatase and mortality was significant across various subgroups of dialysis patients. Surprisingly, this included patients without hepatitis or other liver diseases, which can also cause increased alkaline phosphatase levels; as well as patients who had normal serum liver function or normal nutritional status, reflected by normal serum albumin levels.
In addition, patients whose alkaline phosphatase level increased during the first six months of the study were at higher risk of death over the subsequent two and one-half years.
MEDICA.de; Source: American Society of Nephrology