title: Age-related differences in renal function at onset of renal replacement therapy in chronic kidney disease stage 5 patients.
abstract: BACKGROUND
  Guidelines for initiating renal replacement therapy (RRT) are based on renal function and not age, so renal function at onset of RRT is expected to be similar across age groups.
  
  
  OBJECTIVE
  To evaluate renal function at initiation of RRT across age groups.
  
  
  METHODS
  Observational cross-sectional study.
  
  
  METHODS
  We extracted data for all incident chronic kidney disease (CKD) stage 5 patients (n = 322 064) commenced on chronic dialysis (haemodialysis and peritoneal) and renal transplant in the US from 1995 to 1999 from the US Renal Data Systems (USRDS). Subjects (n = 662) with incomplete data were excluded. The reminder (n = 321 402) were classified into five age groups: 0-19 years; 20-44 years; 45-64 years; 65-74 years; >/=75 years. Mean values of serum creatinine (Cr, mg/dl), creatinine clearance (CrCl, ml/min), body weight (kg) and body mass index (BMI, kg/m(2)) at onset of RRT were computed. Mean daily urinary creatinine excretion per kg body weight (CrCl x Cr/0.07/weight) was also calculated.
  
  
  RESULTS
  Progressively lower serum creatinine levels were found in adult patients with increasing age (10.70, 8.56, 7.38 and 6.88 mg/dl in those aged 20-44 years, 45-64 years, 65-74 years, >/=75 years, respectively). CrCl was also lower in the same groups (14.76, 13.38, 11.63 and 11.60 ml/min, respectively).
  
  
  CONCLUSIONS
  Older patients have a greater reduction in renal function than younger patients at onset of RRT, suggesting a delay in initiation of therapy.
authors.affiliation: Division of Geriatrics, Department of Internal Medicine, University of Virginia Health System, PO Box 800506, Charlottesville, VA 22908-0506, USA. sab2s@virginia.edu
authors.forename: S A
authors.initials: SA
authors.lastname: Balogun
authors.forename: R A
authors.initials: RA
authors.lastname: Balogun
authors.forename: J
authors.initials: J
authors.lastname: Evans
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D001835:Body Weight; D002648:Child; D002675:Child, Preschool; D003404:Creatinine / Q000097:blood*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007223:Infant; D007676:Kidney Failure, Chronic / Q000097:blood* / Q000628:therapy; D007677:Kidney Function Tests; D008297:Male; D008875:Middle Aged; D017582:Renal Replacement Therapy; D014481:United States
chemical_list: D003404:Creatinine