title: Albuminuria, kidney function, and the incidence of cognitive impairment among adults in the United States.
abstract: BACKGROUND
  Albuminuria and estimated glomerular filtration rate (eGFR) are each associated with increased risk of cognitive impairment, but their joint association is unknown.
  
  
  METHODS
  Prospective cohort study.
  
  
  METHODS
  A US national sample of 19,399 adults without cognitive impairment at baseline participating in the REGARDS (Reasons for Geographic and Racial Disparities in Stroke) Study.
  
  
  METHODS
  Albuminuria was assessed using urine albumin-creatinine ratio (UACR) and GFR was estimated using the CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration) equation.
  
  
  RESULTS
  Incident cognitive impairment was defined as score ≤4 on the 6-Item Screener at the last follow-up visit.
  
  
  RESULTS
  During a mean follow-up of 3.8 ± 1.5 years, UACRs of 30-299 and ≥300 mg/g were associated independently with 31% and 57% higher risk of cognitive impairment, respectively, relative to individuals with UACR <10 mg/g. This finding was strongest for those with high eGFRs and attenuated at lower levels (P = 0.04 for trend). Relative to eGFR ≥60 mL/min/1.73 m(2), eGFR <60 mL/min/1.73 m(2) was not associated independently with cognitive impairment. However, after stratifying by UACR, eGFR <60 mL/min/1.73 m(2) was associated with a 30% higher risk of cognitive impairment in participants with UACR <10 mg/g, but not higher UACRs (P = 0.04 for trend).
  
  
  CONCLUSIONS
  Single measures of albuminuria and eGFR, screening test of cognition.
  
  
  CONCLUSIONS
  When eGFR was preserved, albuminuria was associated independently with incident cognitive impairment. When albuminuria was <10 mg/g, low eGFR was associated independently with cognitive impairment. Albuminuria and low eGFR are complementary, but not additive, risk factors for incident cognitive impairment.
authors.affiliation: Division of Nephrology, Stanford University School of Medicine, Palo Alto, CA 94304, USA. mktamura@stanford.edu
authors.forename: Manjula
authors.initials: M
authors.lastname: Kurella Tamura
authors.forename: Paul
authors.initials: P
authors.lastname: Muntner
authors.forename: Virginia
authors.initials: V
authors.lastname: Wadley
authors.forename: Mary
authors.initials: M
authors.lastname: Cushman
authors.forename: Neil A
authors.initials: NA
authors.lastname: Zakai
authors.forename: Brian D
authors.initials: BD
authors.lastname: Bradbury
authors.forename: Brett
authors.initials: B
authors.lastname: Kissela
authors.forename: Fred
authors.initials: F
authors.lastname: Unverzagt
authors.forename: George
authors.initials: G
authors.lastname: Howard
authors.forename: David
authors.initials: D
authors.lastname: Warnock
authors.forename: William
authors.initials: W
authors.lastname: McClellan
mesh_terms: D000368:Aged; D000419:Albuminuria / Q000150:complications* / Q000503:physiopathology*; D003072:Cognition Disorders / Q000453:epidemiology* / Q000209:etiology* / Q000503:physiopathology; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D015994:Incidence; D007668:Kidney / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D014481:United States / Q000453:epidemiology