DENVER—Elevated levels of fibroblast growth factor 23 (FGF-23) are associated with an increased risk for cardiovascular (CV) death among elderly men independent of renal function and other parameters of mineral metabolism, according to Swedish researchers.
The investigators, led by Östen Ljunggre, MD, of Uppsala University in Uppsala, concluded that FGF-23 may be a modifiable risk factor for CV morbidity. Study findings were presented by co-investigator Per-Anton Westerberg, MD, who noted: “We think that understanding the mechanism … will be of great importance in the treatment of persons with an ‘age related’ mild renal dysfunction and also in understanding the relationship between vitamin D metabolism and general health.”
He and his colleagues studied 2,837 men who participated in the Osteoporotic Fractures in Men (MrOS) study and who had FGF-23 levels measured. MrOS enrolled men aged 69-81 years randomly selected from the Swedish population. During a mean follow-up time of 4.5 years, 352 individuals died (12%), 132 (5%) from cardiovascular causes.
After adjusting for other parameters of mineral metabolism and estimated glomerular filtration rate, men in the highest quartile of FGF-23 (57.4-800 pg/mL; median 69.9 pg/mL) had a significantly elevated risk of cardiovascular death compared with subjects in the lowest quartile (3.0-32.4 pg/mL; median 25.3 pg/mL). A rise in FGF-23 level from 13.8 to 23.4, from 23.4 to 41.7, from 41.7 to 74.1, and from 74.1 to 131.8 was associated with a 24% increase in CV mortality risk.
The higher cardiovascular mortality rate in CKD patients is not fully explained by traditional risk factors, Dr. Westerberg observed. In addition, he noted that FGF-23 is associated with endothelial dysfunction, left ventricular hypertrophy, and atherosclerosis, as well as with increased mortality in dialysis patients and cardiovascular death in patients with coronary disease.