title: Insulin resistance is associated with Fibroblast Growth Factor-23 in stage 3-5 chronic kidney disease patients.
abstract: OBJECTIVE
  To determine the associations between insulin resistance, fibroblast growth factor 23 (FGF-23), and coronary artery calcification (CAC) in chronic kidney disease (CKD) patients.
  
  
  BACKGROUND
  FGF-23 is associated with atherosclerosis and cardiovascular disease, but its association with insulin resistance in CKD has not been explored.
  
  
  METHODS
  Cross sectional study of 72 stage 3-5 CKD patients receiving care in Ontario, Canada.
  
  
  METHODS
  Insulin 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.
  
  
  RESULTS
  Median 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).
  
  
  CONCLUSIONS
  Insulin 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.
authors.affiliation: Department of Medicine, Queen's University, Kingston, ON, Canada; Queen's University Vascular Calcification Investigators, Queen's University, Kingston, ON, Canada. Electronic address: garlandj@queensu.ca.
authors.forename: Jocelyn S
authors.initials: JS
authors.lastname: Garland
authors.affiliation: Department of Medicine, Queen's University, Kingston, ON, Canada; Queen's University Vascular Calcification Investigators, Queen's University, Kingston, ON, Canada.
authors.forename: Rachel M
authors.initials: RM
authors.lastname: Holden
authors.affiliation: School of Kinesiology and Health Studies, Departments of Endocrinology and Metabolism, Queen's University, Kingston, ON, Canada.
authors.forename: Robert
authors.initials: R
authors.lastname: Ross
authors.affiliation: Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON, Canada.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Adams
authors.affiliation: Queen's University Vascular Calcification Investigators, Queen's University, Kingston, ON, Canada; Department of Radiology, Queen's University, Kingston, ON, Canada.
authors.forename: Robert L
authors.initials: RL
authors.lastname: Nolan
authors.affiliation: Queen's University Vascular Calcification Investigators, Queen's University, Kingston, ON, Canada; Clinical Research Center, Kingston General Hospital, and Department of Community Health and Epidemiology, Queen's University, Kingston, Ontario, Canada.
authors.forename: Wilma M
authors.initials: WM
authors.lastname: Hopman
authors.affiliation: Department of Medicine, Queen's University, Kingston, ON, Canada; Queen's University Vascular Calcification Investigators, Queen's University, Kingston, ON, Canada.
authors.forename: A Ross
authors.initials: AR
authors.lastname: Morton
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002114:Calcinosis / Q000150:complications / Q000378:metabolism; D003324:Coronary Artery Disease / Q000150:complications / Q000378:metabolism; D003430:Cross-Sectional Studies; D018450:Disease Progression; D005260:Female; D000089703:Fibroblast Growth Factor-23; D005346:Fibroblast Growth Factors / Q000097:blood*; D005919:Glomerular Filtration Rate; D006801:Humans; D007333:Insulin Resistance; D008297:Male; D024821:Metabolic Syndrome / Q000150:complications / Q000378:metabolism; D008875:Middle Aged; D010710:Phosphates / Q000378:metabolism; D051436:Renal Insufficiency, Chronic / Q000150:complications / Q000378:metabolism*
chemical_list: C000717427:FGF23 protein, human; D010710:Phosphates; D005346:Fibroblast Growth Factors; D000089703:Fibroblast Growth Factor-23
keywords: Chronic Kidney Disease; Coronary artery calcification; Fibroblast Growth Factor-23; Insulin Resistance; Phosphorus