title: Earlier onset and greater severity of disordered mineral metabolism in diabetic patients with chronic kidney disease.
abstract: OBJECTIVE
  Disordered mineral metabolism is a common complication of chronic kidney disease (CKD) and a novel risk factor for CKD progression, cardiovascular disease, and mortality. Although diabetes is the leading cause of CKD and is associated with worse clinical outcomes than other etiologies, few studies have evaluated mineral metabolism in CKD according to diabetes status.
  
  
  METHODS
  Using the Chronic Renal Insufficiency Cohort Study, we tested the hypothesis that diabetes is independently associated with lower serum calcium and higher serum phosphate, parathyroid hormone (PTH), and fibroblast growth factor 23 (FGF23).
  
  
  RESULTS
  Compared with participants without diabetes (n = 1,936), those with diabetes (n = 1,820) were more likely to have lower estimated glomerular filtration rate (eGFR), lower serum albumin, and higher urinary protein excretion (all P < 0.001). Unadjusted serum phosphate, PTH, and FGF23 levels were higher and calcium was lower among those with compared with those without diabetes (all P < 0.001). After multivariate adjustment, diabetes remained a significant predictor of serum phosphate, PTH, and FGF23 but not calcium. The eGFR cut point at which 50% of participants met criteria for secondary hyperparathyroidism or elevated FGF23 was higher in participants with diabetes compared with those without (PTH: eGFR 30-39 vs. 20-29, P < 0.001; FGF23: eGFR 50-59 vs. 40-49, P < 0.001).
  
  
  CONCLUSIONS
  Disordered mineral metabolism begins earlier in the course of CKD and is more severe among CKD patients with compared with those without diabetes. Future studies should explore mechanisms for these differences and whether they contribute to excess risks of adverse clinical outcomes among diabetic patients with CKD.
authors.affiliation: Division of Nephrology and Hypertension, Department of Medicine, University ofMiami Miller School of Medicine, Miami, Florida, USA.
authors.forename: Patricia
authors.initials: P
authors.lastname: Wahl
authors.forename: Huiliang
authors.initials: H
authors.lastname: Xie
authors.forename: Julia
authors.initials: J
authors.lastname: Scialla
authors.forename: Cheryl A M
authors.initials: CA
authors.lastname: Anderson
authors.forename: Keith
authors.initials: K
authors.lastname: Bellovich
authors.forename: Carolyn
authors.initials: C
authors.lastname: Brecklin
authors.forename: Jing
authors.initials: J
authors.lastname: Chen
authors.forename: Harold
authors.initials: H
authors.lastname: Feldman
authors.forename: Orlando M
authors.initials: OM
authors.lastname: Gutierrez
authors.forename: Jim
authors.initials: J
authors.lastname: Lash
authors.forename: Mary B
authors.initials: MB
authors.lastname: Leonard
authors.forename: Lavinia
authors.initials: L
authors.lastname: Negrea
authors.forename: Sylvia E
authors.initials: SE
authors.lastname: Rosas
authors.forename: Amanda Hyre
authors.initials: AH
authors.lastname: Anderson
authors.forename: Raymond R
authors.initials: RR
authors.lastname: Townsend
authors.forename: Myles
authors.initials: M
authors.lastname: Wolf
authors.forename: Tamara
authors.initials: T
authors.lastname: Isakova
mesh_terms: D000328:Adult; D000368:Aged; D002118:Calcium / Q000097:blood; D003920:Diabetes Mellitus / Q000097:blood* / Q000378:metabolism; D005260:Female; D000089703:Fibroblast Growth Factor-23; D005346:Fibroblast Growth Factors / Q000097:blood; D005919:Glomerular Filtration Rate / Q000502:physiology; D006801:Humans; D007674:Kidney Diseases / Q000097:blood* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood; D010710:Phosphates / Q000097:blood
chemical_list: C000717427:FGF23 protein, human; D010281:Parathyroid Hormone; D010710:Phosphates; D005346:Fibroblast Growth Factors; D000089703:Fibroblast Growth Factor-23; D002118:Calcium