title: Determinants of fibroblast growth factor-23 and parathyroid hormone variability in dialysis patients.
abstract: OBJECTIVE
  Treatment strategies for abnormal mineral metabolism in chronic kidney disease are largely based on achieving target ranges of biomarkers that vary considerably over time, yet determinants of their variability are poorly defined.
  
  
  METHODS
  Observational study including 162 patients of three dialysis cohorts (peritoneal dialysis, n = 78; hemodialysis, n = 49; hemodiafiltration, n = 35). Clinical and biochemical determinants of parathyroid hormone (PTH) and fibroblast growth factor-23 (FGF23) variability were analyzed in the peritoneal dialysis cohort. All cohorts were used for comparison of PTH and FGF23 intra-subject variability (intra-class correlation), and their intra-subject variability in different modes of dialysis was explored.
  
  
  RESULTS
  High PTH variability was independently associated with lower 25-hydroxyvitamin D concentration and factors of lipid and glucose metabolism, whereas high FGF23 variability was mainly associated with lower baseline serum phosphorous. These results were consistent in multivariate and sensitivity analyses. The intra-subject variability of FGF23 was lower than for PTH irrespective of dialysis mode.
  
  
  CONCLUSIONS
  Baseline vitamin D status and serum phosphorous are independent determinants of the longitudinal variation in PTH and FGF23, respectively. The clinical utility of FGF23 measurement remains unknown, yet it appears favorable based on its greater temporal stability than PTH in dialysis patients.
authors: Division of Renal Medicine, Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden.
authors: Ting
authors: T
authors: Jia
authors: Abdul Rashid
authors: AR
authors: Qureshi
authors: Vincent
authors: V
authors: Brandenburg
authors: Markus
authors: M
authors: Ketteler
authors: Peter
authors: P
authors: Barany
authors: Olof
authors: O
authors: Heimburger
authors: Fredrik
authors: F
authors: Uhlin
authors: Per
authors: P
authors: Magnusson
authors: Anders
authors: A
authors: Fernström
authors: Bengt
authors: B
authors: Lindholm
authors: Peter
authors: P
authors: Stenvinkel
authors: Tobias E
authors: TE
authors: Larsson
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D015331:Cohort Studies; D005260:Female; D000089703:Fibroblast Growth Factor-23; D005346:Fibroblast Growth Factors / Q000097:blood*; D017583:Hemodiafiltration; D006801:Humans; D007676:Kidney Failure, Chronic / Q000097:blood / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood*; D010530:Peritoneal Dialysis; D010758:Phosphorus / Q000097:blood; D014807:Vitamin D / Q000097:blood
chemical_list: D015415:Biomarkers; C000717427:FGF23 protein, human; D010281:Parathyroid Hormone; D014807:Vitamin D; D010758:Phosphorus; D005346:Fibroblast Growth Factors; D000089703:Fibroblast Growth Factor-23