title: Relationship between serum phosphorus and the progression of advanced chronic kidney disease.
abstract: BACKGROUND
  High serum phosphorus (P) has been shown to be associated with a more rapid decline of renal function in patients with chronic kidney disease (CKD).
  
  
  OBJECTIVE
  The aim of this study was to determine whether time-averaged serum P levels are associated with the progression of renal failure adjusted for other potential confounders.
  
  
  METHODS
  A prospective observational study of 184 patients with pre-dialysis CKD, stages 3, 4 and 5 (mean GFR=15.2±5.6 ml/min/1.73 m2). The rate of decline in renal function was calculated as the slope of GFR. Median follow-up time was 303 days. Biochemical parameters were analysed as time-averaged concentrations. Multivariate linear regression analysis was used to assess the best determinants of serum P levels, and the relationship between the rate of decline of renal function and the study covariates.
  
  
  RESULTS
  The best determinants of serum P levels were: GFR (beta = 0.477), female sex (beta = 0.106), serum calcium (beta = -0.274), serum albumin (beta = -0.112), serum bicarbonate (beta = -0.182), protein catabolic rate (beta = 0.144), and use of diuretics (beta = 0.180). The mean ± standard deviation (SD) slope of GFR was -0.198±0.376 ml/min/month. The best determinants of the slope of GFR were: proteinuria (beta = -0.462), serum P (beta = -0.440), and basal GFR (beta = -0.404). Total urinary P excretion was not significantly associated with the rate of decline of renal function.
  
  
  CONCLUSIONS
  High serum P levels are strongly and independently associated with a more rapid decline of renal function in patients with advanced CKD.
authors: Nephrology Department, Infanta Cristina Hospital, Avda. Elvas s/n, Badajoz, Spain. fcaravacam@senefro.org
authors: F
authors: F
authors: Caravaca
authors: J
authors: J
authors: Villa
authors: E
authors: E
authors: García de Vinuesa
authors: C
authors: C
authors: Martínez del Viejo
authors: R
authors: R
authors: Martínez Gallardo
authors: R
authors: R
authors: Macías
authors: F
authors: F
authors: Ferreira
authors: I
authors: I
authors: Cerezo
authors: R
authors: R
authors: Hernández-Gallego
mesh_terms: D000368:Aged; D001639:Bicarbonates / Q000097:blood; D015415:Biomarkers; D002117:Calcitriol / Q000627:therapeutic use; D002118:Calcium / Q000378:metabolism; D002614:Chelating Agents; D002908:Chronic Disease; D015986:Confounding Factors, Epidemiologic; D018450:Disease Progression; D004232:Diuretics / Q000627:therapeutic use; D005260:Female; D005500:Follow-Up Studies; D005919:Glomerular Filtration Rate; D006801:Humans; D054559:Hyperphosphatemia / Q000453:epidemiology / Q000209:etiology*; D007674:Kidney Diseases / Q000097:blood* / Q000150:complications / Q000188:drug therapy; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood; D010758:Phosphorus / Q000097:blood*; D011237:Predictive Value of Tests; D011446:Prospective Studies
chemical_list: D001639:Bicarbonates; D015415:Biomarkers; D002614:Chelating Agents; D004232:Diuretics; D010281:Parathyroid Hormone; D010758:Phosphorus; D002117:Calcitriol; D002118:Calcium