title: Introduction of the CKD-EPI equation to estimate glomerular filtration rate in a Caucasian population.
abstract: BACKGROUND
  Chronic kidney disease (CKD) is defined as the presence of kidney damage, albuminuria or a reduction in glomerular filtration rate (GFR). A GFR <60 mL/min/1.73 m(2) alone is sufficient to diagnose CKD Stages III-V. Recently, the new chronic kidney disease epidemiology collaboration (CKD-EPI) equation was introduced. It has been suggested to result in higher estimated glomerular filtration rates (eGFRs) than the Modification of Diet in Renal Disease (MDRD(4)) formula. Here, we assess consequences of introducing the CKD-EPI equation in a West European Caucasian population.
  
  
  METHODS
  Data were obtained from 6097 Caucasian participants of the Nijmegen Biomedical Study (2823 males and 3274 females). Serum creatinine values were determined using the Jaffe method, calibrated against mass spectrometry and were used to calculate eGFR(MDRD4) and eGFR(CKD-EPI). Demographic data, health status and information on medication use for all participants was obtained with a postal questionnaire.
  
  
  RESULTS
  The introduction of the CKD-EPI equation changed the curve of eGFR by age, with higher values in the younger age groups and a steeper decline of eGFR with ageing. As a consequence, younger people were more often classified to a higher GFR stage and older people, especially males, to a lower GFR stage.
  
  
  CONCLUSIONS
  In comparison with the MDRD(4) formula, the CKD-EPI equation leads to higher estimates of GFR in young people and lower estimates in the elderly. On a population level, this may lead to higher estimates of kidney function. However, in routine clinical practice where the population is predominantly elderly, the opposite may be true. The introduction of eGFR(CKD-EPI) necessitates reconsidering the definition of CKD. We suggest introducing age-dependent threshold values and/or the use of urinary albumin excretion to improve risk stratification.
authors.affiliation: Department of Nephrology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands. a.vandenbrand@nier.umcn.nl
authors.forename: Jan A J G
authors.initials: JA
authors.lastname: van den Brand
authors.forename: Gerben A J
authors.initials: GA
authors.lastname: van Boekel
authors.forename: Hans L
authors.initials: HL
authors.lastname: Willems
authors.forename: Lambertus A L M
authors.initials: LA
authors.lastname: Kiemeney
authors.forename: Martin
authors.initials: M
authors.lastname: den Heijer
authors.forename: Jack F M
authors.initials: JF
authors.lastname: Wetzels
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000419:Albuminuria / Q000453:epidemiology* / Q000209:etiology; D003299:Cooperative Behavior; D003404:Creatinine / Q000097:blood; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007676:Kidney Failure, Chronic / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D044465:White People / Q000706:statistics & numerical data*; D055815:Young Adult
chemical_list: D003404:Creatinine