Fibroblast Growth Factor 23 and Mortality in Patients With Type 2 Diabetes and Normal or Mildly Impaired Kidney Function

OBJECTIVE To study whether fibroblast growth factor 23 (FGF23) is associated with adverse outcomes in patients with type 2 diabetes and normal or mildly impaired kidney function. RESEARCH DESIGN AND METHODS We analyzed C-terminal FGF23 levels in 310 patients with type 2 diabetes and estimated glomerular filtration rate >= 60 mL/min/1.73 m(2). Associations of FGF23 with all-cause mortality and major adverse cardiovascular events (MACE) were studied by Cox regression. RESULTS During a follow-up of 5.8 years (3.3-6.5), 47 patients developed MACE and 28 patients died. FGF23 was associated with an increased risk of all-cause mortality (age- and sex-adjusted hazard ratio 2.78 [95% CI 1.76-4.40]) and MACE (1.67 [1.12-2.49]). Results were similar after additional adjustment for other potential confounders and were consistent upon replication in an independent cohort. CONCLUSIONS In patients with type 2 diabetes and normal or mildly impaired kidney function, FGF23 is associated with an increased risk of cardiovascular events and mortality.