Albuminuria, kidney function, and the incidence of cognitive impairment among adults in the United States.

Academic Article

Abstract

  • BACKGROUND: Albuminuria and estimated glomerular filtration rate (eGFR) are each associated with increased risk of cognitive impairment, but their joint association is unknown. STUDY DESIGN: Prospective cohort study. SETTING & PARTICIPANTS: 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. PREDICTORS: Albuminuria was assessed using urine albumin-creatinine ratio (UACR) and GFR was estimated using the CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration) equation. OUTCOMES: 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). LIMITATIONS: 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.
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    Keywords

  • Aged, Albuminuria, Cognition Disorders, Female, Glomerular Filtration Rate, Humans, Incidence, Kidney, Male, Middle Aged, Prospective Studies, United States
  • Digital Object Identifier (doi)

    Author List

  • Kurella Tamura M; Muntner P; Wadley V; Cushman M; Zakai NA; Bradbury BD; Kissela B; Unverzagt F; Howard G; Warnock D
  • Start Page

  • 756
  • End Page

  • 763
  • Volume

  • 58
  • Issue

  • 5