title: Renal insufficiency in the absence of albuminuria and retinopathy among adults with type 2 diabetes mellitus.
abstract: BACKGROUND
  Kidney disease in type 2 diabetes mellitus (DM) is more heterogeneous than in type 1 DM. Reduced glomerular filtration rate (GFR) among individuals with type 2 DM may not always be due to classic diabetic glomerulosclerosis, which is associated with albuminuria and retinopathy.
  
  
  OBJECTIVE
  To determine the prevalence of chronic renal insufficiency (CRI), defined as a GFR less than 60 mL/min per 1.73 m2 body surface area (BSA) in the absence of microalbuminuria or macroalbuminuria and diabetic retinopathy among adults with type 2 DM.
  
  
  METHODS
  Cross-sectional analysis of adults aged 40 years or older with type 2 DM in the Third National Health and Nutrition Examination Survey, a probability sample of the total civilian US noninstitutionalized population conducted from 1988-1994.
  
  
  METHODS
  The GFR per 1.73 m2 BSA, calculated with serum creatinine, urea nitrogen, and serum albumin levels using the Modification of Diet in Renal Disease Study prediction equation; albuminuria, assessed using spot urine albumin/creatinine ratio; and presence of retinopathy, determined with fundus photography.
  
  
  RESULTS
  Overall, 13% (sampled n = 171) of adults with type 2 DM (n = 1197) had CRI with a population estimate of 1.1 million. Among these adults with CRI, diabetic retinopathy was noted in 28% (n = 58), while the frequencies of microalbuminuria and macroalbuminuria were 45% (n = 64) and 19% (n = 47), respectively. Retinopathy and albuminuria (microalbuminuria or macroalbuminuria) were both absent in 30% (n = 51) of adults with type 2 DM and CRI. The population estimate of adults with type 2 DM and CRI in the absence of diabetic retinopathy or albuminuria was approximately 0.3 million.
  
  
  CONCLUSIONS
  A substantial burden of CRI among persons with type 2 DM in the United States is likely due to renal parenchymal disease other than classic diabetic glomerulosclerosis. Approaches to screening renal disease in the type 2 DM population should incorporate assessment of GFR in addition to monitoring urine albumin excretion and funduscopic changes to ensure that individuals with type 2 DM and CRI not due to diabetic glomerulosclerosis will receive appropriate intervention.
authors.affiliation: Department of Preventive Medicine, Division of Nephrology, Loyola University Medical Center, Maywood, IL 60153, USA. hkramer@lumc.edu
authors.forename: Holly J
authors.initials: HJ
authors.lastname: Kramer
authors.forename: Quan Dong
authors.initials: QD
authors.lastname: Nguyen
authors.forename: Gary
authors.initials: G
authors.lastname: Curhan
authors.forename: Chi-Yuan
authors.initials: CY
authors.lastname: Hsu
mesh_terms: D000328:Adult; D000419:Albuminuria / Q000453:epidemiology; D003924:Diabetes Mellitus, Type 2 / Q000150:complications*; D003928:Diabetic Nephropathies / Q000453:epidemiology*; D003930:Diabetic Retinopathy / Q000453:epidemiology; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D009749:Nutrition Surveys; D015995:Prevalence; D051437:Renal Insufficiency / Q000453:epidemiology* / Q000209:etiology*; D014481:United States / Q000453:epidemiology