Fibroblast growth factor 23 and cause-specific mortality in the general population: The northern Manhattan study

Context: An elevated fibroblast growth factor (FGF) 23 is an independent risk factor for cardiovascular disease and mortality in patients with kidney disease. The relationship between FGF23 and cause-specific mortality in the general population is unknown. Objective: To investigate the association of elevated FGF23 with the risk of cause-specific mortality in a racially and ethnically diverse urban general population. Design, Setting, Participants: The Northern Manhattan Study is a population-based prospective cohort study. Residents who were > 39 years old and had no history of stroke were enrolled between 1993 and 2001. Participants with available blood samples for baseline FGF23 testing were included in the current study (n = 2525). Main Outcome Measures: Cause-specific death events. Results: A total of 1198 deaths (474 vascular, 612 nonvascular, 112 unknown cause) occurred during a median follow-up of 14 years. Compared to participants in the lowest FGF23 quintile, those in the highest quintile had a 2.07-fold higher risk (95% confidence interval [CI], 1.45, 2.94) of vascular death and a 1.64-fold higher risk (95% CI, 1.22, 2.20) of nonvascular death in fully adjusted models. Higher FGF23 was independently associated with increased risk of mortality due to cancer, but only in Hispanic participants (hazard ratio per 1 unit increase in ln FGF23 of 1.87; 95% CI, 1.40, 2.50; P for interaction =.01). Conclusions: Elevated FGF23 was independently associated with increased risk of vascular and nonvascular mortality in a diverse general population and with increased risk of cancer death specifically in Hispanic individuals.