TUESDAY, June 14 (HealthDay News) -- Patients with early-stage
chronic kidney disease are more likely to die if they have elevated
levels of a certain hormone, a new study says.
Endocrine hormone fibroblast growth factor 23 (FGF-23) regulates
phosphorus metabolism. It was known that levels of FGF-23 increase
as kidney function declines and that high levels of the hormone are
associated with increased risk of death in patients with kidney
failure. But little was known about how elevated levels of FGF-23
affect outcomes of patients with early-stage chronic kidney
This study looked at 3,879 patients with early-stage chronic
kidney disease. During a median follow-up of 3.5 years, 266 of the
patients died and 410 progressed to kidney failure. The researchers
found that median FGF-23 levels were higher in these patients than
in those who remained "event-free."
Patients with the highest levels of FGF-23 were 4.3 times more
likely to die than those with the lowest levels, according to the
study in the June 15 issue of the
Journal of the American Medical Association.
The researchers said they were surprised to find that high
FGF-23 levels were more strongly associated with death than other
factors, including cardiovascular disease and chronic kidney
disease-specific risk factors such as reduced estimated glomerular
filtration rate (GFR, a measure of the kidney's ability to filter
out and remove waste products) and proteinuria (excessive protein
in the urine).
The reasons for the link between elevated FGF-23 levels and
increased risk of death aren't known.
"If the results of the current study are confirmed and experimental studies support the hypothesis of direct toxicity of FGF-23, future research should evaluate whether therapeutic or preventative strategies that lower FGF-23 can improve outcomes," Dr. Tamara Isakova, of the University of Miami Miller School of Medicine, and colleagues said in a news release from the journal.
The American Academy of Family Physicians has more about
chronic kidney disease.