Elevated levels of fibroblast growth factor 23 (FGF-23), a bone-derived hormone that regulates phosphorus and vitamin D metabolism, are associated with a low body mass index (BMI) and dyslipidemia in dialysis patients, a study found.
Previous research has demonstrated associations between elevated FGF-23 levels and an increased risk of death among patients on hemodialysis (HD) and those with moderate to severe chronic kidney disease not yet requiring dialysis.
In a study of 654 HD patients (98% male), Jessica Kendrick, MD, of the University of Colorado Denver, and colleagues found that increasing FGF-23 levels were associated with decreasing BMI, total cholesterol, LDL-cholesterol, and HDL-cholesterol after adjusting for age, race, gender, markers of mineral metabolism, cardiovascular risk factors, serum albumin, and use of lipid-lowering drugs, according to a report in the American Journal of Nephrology (2013;37:183-190).
In one model that adjusted for age, gender, race, and certain other variables, including BMI, total cholesterol, LDL-cholesterol, and triglycerides, patients in the highest quartile of FGF-23 concentration (13,817 RU/mL or higher) had a 69% increased risk of death from any cause compared with those in the lowest quartile (less than 1,411 RU/mL). The increased risk dropped to 53% after investigators adjusted for HDL-cholesterol.
As a result of their findings, researchers concluded that the association between FGF-23 and mortality in dialysis patients “may be mediated through unexplored metabolic risk factors unrelated to mineral metabolism,” the researchers wrote.