title: Mineral metabolites and CKD progression in African Americans.
abstract: CKD progresses more rapidly to ESRD among African Americans compared with Caucasians. Disordered mineral metabolism is more severe among African Americans with CKD, which might partially explain the accelerated progression of their kidney disease. Here, using data from the African American Study of Kidney Disease and Hypertension, we evaluated longitudinal changes in serum levels of fibroblast growth factor-23 (FGF23), parathyroid hormone (PTH), phosphate, and 25-hydroxyvitamin D in a subset of 420 participants followed for a median of 4 years. We also examined the association of baseline levels of mineral metabolites with risk for ESRD or death in 809 participants. FGF23, PTH, and phosphate levels rose over time; participants with faster rates of decline in measured GFR had the greatest increases in these parameters (P<0.01 for each). Higher baseline levels of FGF23, PTH, and phosphate each associated with increased risk for ESRD or death independent of GFR. FGF23 exhibited a dose-response relationship with outcomes (HR=1.30 per doubling, 95% CI=1.15-1.47; HR=2.24 for highest compared with lowest quartile, 95% CI=1.39-3.60), whereas PTH and phosphate showed nonlinear relationships. Vitamin D insufficiency (<30 ng/ml) was present in 95% of participants, but lower levels did not independently associate with outcomes. Using death-censored ESRD as the outcome produced qualitatively similar results. In conclusion, abnormalities of mineral metabolism worsen with progressive CKD and associate with higher risk for ESRD among African Americans with hypertensive nephrosclerosis.
authors.affiliation: Division of Nephrology and Hypertension, Department of Medicine, University of Miami Miller School of Medicine, Miami, Florida, USA.
authors.forename: Julia J
authors.initials: JJ
authors.lastname: Scialla
authors.forename: Brad C
authors.initials: BC
authors.lastname: Astor
authors.forename: Tamara
authors.initials: T
authors.lastname: Isakova
authors.forename: Huiliang
authors.initials: H
authors.lastname: Xie
authors.forename: Lawrence J
authors.initials: LJ
authors.lastname: Appel
authors.forename: Myles
authors.initials: M
authors.lastname: Wolf
mesh_terms: D001741:Black or African American; D000368:Aged; D003287:Contrast Media; D018450:Disease Progression; D005260:Female; D000089703:Fibroblast Growth Factor-23; D005346:Fibroblast Growth Factors / Q000097:blood*; D005919:Glomerular Filtration Rate; D006801:Humans; D007457:Iodine Radioisotopes; D007483:Iothalamic Acid; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D008903:Minerals / Q000378:metabolism; D010281:Parathyroid Hormone / Q000097:blood*; D010710:Phosphates / Q000097:blood*; D016032:Randomized Controlled Trials as Topic; D051436:Renal Insufficiency, Chronic / Q000097:blood*; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood
chemical_list: D003287:Contrast Media; C000717427:FGF23 protein, human; D007457:Iodine Radioisotopes; D008903:Minerals; D010281:Parathyroid Hormone; D010710:Phosphates; D014807:Vitamin D; D007483:Iothalamic Acid; D005346:Fibroblast Growth Factors; D000089703:Fibroblast Growth Factor-23; C104450:25-hydroxyvitamin D