Hormone predicts which kidney patients might die early

Blood test could identify patients who need treatment

13-Sep-2011 - USA

The blood levels of a particular hormone can help predict which kidney disease patients will develop heart problems, need dialysis, and die prematurely, according to a study appearing in an upcoming issue of the Journal of the American Society nephrology (JASN). Testing for this hormone could identify which patients need early treatment, thereby lowering their health risks and lengthening their lives.

In patients with chronic kidney disease (CKD), blood levels of a hormone called fibroblast growth factor-23 (FGF-23) rise in parallel with declining kidney function. Researchers have wondered whether FGF-23 levels might also predict which CKD patients will develop heart problems (the number one killer of CKD patients), need dialysis, or die prematurely.

To find out, Jessica Kendrick, MD, Michel Chonchol, MD (University of Colorado), and their colleagues measured FGF-23 levels in the blood of 1,099 patients with advanced CKD, dividing patients into four groups or quartiles based on their FGF-23 levels. After following patients for an average of 2.9 years, the researchers found that more patients in the groups with higher FGF-23 levels developed heart problems, needed dialysis, and died than those with lower levels of the hormone. Specifically, compared with the group with the lowest levels of FGF-23, each subsequent quartile had a progressively higher risk of dying during the study. The two highest quartiles had significantly elevated risks for developing heart problems and needing dialysis.

The findings suggest that blood levels of FGF-23 might be used to guide therapies in patients with CKD. "FGF-23 may be a modifiable risk factor in patients with CKD as it strongly associated with the most important outcomes encountered by these patients: death, cardiovascular events, and initiation of dialysis," said Dr. Chonchol. Additional studies are needed to determine whether treatments to lower FGF-23 levels benefit CKD patients.