title: Estimated albumin excretion rate versus urine albumin-creatinine ratio for the assessment of albuminuria: a diagnostic test study from the Prevention of Renal and Vascular Endstage Disease (PREVEND) Study.
abstract: BACKGROUND
  Albumin-creatinine ratio (ACR) in spot urine samples is recommended for albuminuria screening instead of measured albumin excretion rate (mAER) in 24-hour urine collections. In patients with extremes of muscle mass, differences in spot urine creatinine values may lead to under- or overestimation of mAER by ACR. We hypothesized that calculating estimated AER (eAER) using spot ACR and estimated creatinine excretion rate (eCER) may improve albuminuria assessment.
  
  
  METHODS
  Diagnostic test study.
  
  
  METHODS
  2,711 community-living individuals from the general population of the Netherlands participating in the PREVEND (Prevention of Renal and Vascular Endstage Disease) Study.
  
  
  METHODS
  eAER was computed as the product of ACR and eCER. eCER was computed using 3 previously validated methods (Ix, Ellam, and Walser).
  
  
  METHODS
  mAER, based on two 24-hour urine collections. Accuracy of the eAER and ACR were defined as the percentage of participants falling within 30% (P30) of mAER.
  
  
  RESULTS
  Mean age was 49 years, 46% were men, mean estimated glomerular filtration rate was 84 ± 15 mL/min/1.73 m(2), and median mAER was 7.2 (IQR, 5.4-11.0) mg/d. Mean measured CER was 1,381 mg/d, and median ACR was 4.9 mg/g. Using the Ix equation, median eAER was 6.4 mg/d. In the full cohort, eAER was more accurate and less biased compared to ACR (P30, 48.9% vs 33.6%; bias, -34.2% vs -14.1%, respectively). In subgroup analysis, improvement was most notable in the middle and highest weight tertiles and in men. Using the other methods for eCER produced similar results.
  
  
  CONCLUSIONS
  Little ethnic heterogeneity and a generally healthy cohort make extension of findings to other races and the chronically ill uncertain.
  
  
  CONCLUSIONS
  In a large community-dwelling cohort, eAER was more accurate than ACR in assessing albuminuria.
authors.affiliation: Division of Nephrology, Department of Medicine, University of California, San Diego, CA; Veterans Affairs San Diego Healthcare System, San Diego, CA. Electronic address: jabdelmalek@ucsd.edu.
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Abdelmalek
authors.affiliation: Department of Internal Medicine, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.
authors.forename: Ron T
authors.initials: RT
authors.lastname: Gansevoort
authors.affiliation: Department of Clinical Pharmacology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.
authors.forename: Hiddo J
authors.initials: HJ
authors.lastname: Lambers Heerspink
authors.affiliation: Division of Nephrology, Department of Medicine, University of California, San Diego, CA; Veterans Affairs San Diego Healthcare System, San Diego, CA; Division of Preventive Medicine, Department of Family and Preventive Medicine, University of California, San Diego, San Diego, CA.
authors.forename: Joachim H
authors.initials: JH
authors.lastname: Ix
authors.affiliation: Division of Nephrology, Department of Medicine, University of California, San Diego, CA; Veterans Affairs San Diego Healthcare System, San Diego, CA; Division of Preventive Medicine, Department of Family and Preventive Medicine, University of California, San Diego, San Diego, CA.
authors.forename: Dena E
authors.initials: DE
authors.lastname: Rifkin
mesh_terms: D000328:Adult; D000368:Aged; D000419:Albuminuria / Q000652:urine*; D015415:Biomarkers / Q000652:urine; D003404:Creatinine / Q000652:urine*; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007676:Kidney Failure, Chronic / Q000175:diagnosis* / Q000517:prevention & control / Q000652:urine; D008297:Male; D008875:Middle Aged; D009426:Netherlands; D011237:Predictive Value of Tests; D012372:ROC Curve; D015203:Reproducibility of Results
chemical_list: D015415:Biomarkers; D003404:Creatinine
keywords: Albuminuria; albumin-creatinine ratio; creatinine excretion