Insulin resistance is associated with Fibroblast Growth Factor-23 in stage 3–5 chronic kidney disease patients

Abstract

AimTo determine the associations between insulin resistance, fibroblast growth factor 23 (FGF-23), and coronary artery calcification (CAC) in chronic kidney disease (CKD) patients. IntroductionFGF-23 is associated with atherosclerosis and cardiovascular disease, but its association with insulin resistance in CKD has not been explored. SubjectsCross sectional study of 72 stage 3–5 CKD patients receiving care in Ontario, Canada. Materials and MethodsInsulin resistance was measured by the homeostasis model assessment of insulin resistance (HOMA-IR), FGF-23 was measured by carboxyl terminal enzyme linked immunoassay (ctFGF-23) and CAC was measured by multi-slice computed tomography. ResultsMedian HOMA-IR was 2.19μU/ml (interquartile range 1.19 to 3.94). Patients with HOMA-IR>2.2 had greater ctFGF-23 (179.7 vs 109.6; P=0.03), and 40% higher log CAC scores (2.09±0.87 vs 1.58±1.26; P=0.049). Multivariable linear regression adjusted for 1,25 dihydroxyvitamin D, kidney function, and parathyroid hormone revealed insulin resistance was a risk factor for greater log ctFGF-23 levels (log HOMA IR β=0.37; 95% confidence interval 0.14 to 0.59; P=0.002). ConclusionsInsulin resistant CKD patients demonstrated higher FGF-23 levels, and increased CAC, while PO4 levels remained normal, suggesting a potential link between insulin resistance and PO4 homeostasis in CKD.