ABSTRACT: OBJECTIVES:This study sought to determine the association of fibroblast growth factor (FGF)-23 with death, heart failure (HF), and cardiovascular disease (CVD) in the general population, as well as the influence of chronic kidney disease (CKD) in this setting. BACKGROUND:FGF-23 increases renal phosphorus excretion and inhibits vitamin D activation. In end-stage renal disease, high FGF-23 levels are associated with mortality. The association of FGF-23 with death, HF, and CVD in the general population, and the influence of CKD in this setting, are unknown. METHODS:Plasma FGF-23 was measured in 3,107 community-living persons ? 65 years of age in 1996 and 1997, and participants were followed through 2008. HF and CVD events were adjudicated by a panel of experts. Associations of FGF-23 with each outcome were evaluated using Cox proportional hazards models, and we tested whether associations differed by CKD status. RESULTS:Both lower estimated glomerular filtration rate and higher urine albumin to creatinine ratios were associated with high FGF-23 at baseline. During 10.5 years (median) follow-up, there were 1,730 deaths, 697 incident HF events, and 797 incident CVD events. Although high FGF-23 concentrations were associated with each outcome in combined analyses, the associations were consistently stronger for those with CKD (p interactions all <0.006). In the CKD group (n = 1,128), the highest FGF-23 quartile had adjusted hazards ratios (HR) of 1.87 (95% confidence interval [CI]: 1.47 to 2.38) for all-cause death, 1.94 (95% CI: 1.32 to 2.83) for incident HF, and 1.49 (95% CI: 1.02 to 2.18) for incident CVD events compared with the lowest quartile. Corresponding HRs in those without CKD (n = 1,979) were 1.29 (95% CI: 1.05 to 1.59), 1.37 (95% CI: 0.99 to 1.89), and 1.07 (95% CI: 0.79 to 1.45). CONCLUSIONS:FGF-23, a hormone involved in phosphorous and vitamin D homeostasis, is independently associated with all-cause death and incident HF in community-living older persons. These associations appear stronger in persons with CKD.