title: Sequence of progression of albuminuria and decreased GFR in persons with type 1 diabetes: a cohort study.
abstract: BACKGROUND
  The sensitivity of albuminuria in predicting loss of kidney function has been questioned. We determined the sequence of kidney disease stages (microalbuminuria, macroalbuminuria, low estimated glomerular filtration rate [eGFR], and end-stage renal disease [ESRD]) and characterized those without albuminuria before a low eGFR.
  
  
  METHODS
  The Pittsburgh Epidemiology of Diabetes Complications Study is a prospective cohort investigation of childhood-onset type 1 diabetes.
  
  
  METHODS
  480 study participants with eGFR greater than 60 mL/min/1.73 m(2) (mean age, 27 years; diabetes duration, 19 years at study entry) were prospectively followed up for 16 years.
  
  
  METHODS
  Low eGFR was defined as creatinine clearance less than 60 mL/min/1.73 m(2) from timed urine collections; microalbuminuria, as albumin excretion rate between 20 to 200 microg/min (30 to 300 mg/24 h); macroalbuminuria, as albumin excretion rate greater than 200 microg/min (>300 mg/24 h); and ESRD, as dialysis or renal transplantation.
  
  
  RESULTS
  The 33 of 480 individuals (7%) who developed ESRD had prior albuminuria. 71 of 480 (15%) individuals developed low eGFR. 66 of 71 (93%) had prior/concurrent albuminuria, and 5 of 71 (7%) did not. Incident low eGFR values in the 5 patients were: (1) 54, (2) 58, (3) 59, (4) 59.7, and (5) 59.8 mL/min/1.73 m(2). 3 of 5 (60%; patients 1, 4, and 5) subsequently developed albuminuria. Final eGFRs in the 5 patients were: (1) 94, (2) 86, (3) 60, (4) 65, and (5) 54 mL/min/1.73 m(2), respectively.
  
  
  CONCLUSIONS
  GFR and insulin sensitivity were not measured, but estimated. Incident decreased eGFR in patients without preceding/concurrent albuminuria may be caused by misclassification or a temporary eGFR decrease.
  
  
  CONCLUSIONS
  Moderately decreased eGFR may occur rarely in patients with type 1 diabetes without preceding albuminuria.
authors.affiliation: Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA 15213, USA.
authors.forename: Tina
authors.initials: T
authors.lastname: Costacou
authors.forename: Demetrius
authors.initials: D
authors.lastname: Ellis
authors.forename: Linda
authors.initials: L
authors.lastname: Fried
authors.forename: Trevor J
authors.initials: TJ
authors.lastname: Orchard
mesh_terms: D000328:Adult; D000419:Albuminuria / Q000453:epidemiology*; D015331:Cohort Studies; D003404:Creatinine / Q000097:blood; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000503:physiopathology*; D003928:Diabetic Nephropathies / Q000097:blood / Q000453:epidemiology* / Q000503:physiopathology; D018450:Disease Progression; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007676:Kidney Failure, Chronic / Q000453:epidemiology; D008297:Male; D012680:Sensitivity and Specificity
chemical_list: D003404:Creatinine