title: Frequency of and risk factors for poor cognitive performance in hemodialysis patients.
abstract: OBJECTIVE
  There are few detailed data on cognition in patients undergoing dialysis. We evaluated the frequency of and risk factors for poor cognitive performance using detailed neurocognitive testing.
  
  
  METHODS
  In this cross-sectional cohort study, 314 hemodialysis patients from 6 Boston-area hemodialysis units underwent detailed cognitive assessment. The neuropsychological battery assessed a broad range of functions, with established age-, sex-, and education-matched normative scores. Principal component analysis was used to derive composite scores for memory and executive function domains. Risk factors for each domain were evaluated using linear regression adjusting for age, sex, race, and education status. Analyses were repeated in those with Mini-Mental State Examination (MMSE) score ≥ 24.
  
  
  RESULTS
  Compared with population norms, patients on dialysis had significantly poorer executive function but not memory performance, a finding that persisted in the subgroup with MMSE score ≥ 24. In adjusted analyses, vascular risk factors and vascular disease were associated with lower executive function (p < 0.01).
  
  
  CONCLUSIONS
  There is a high frequency of poor cognitive performance in hemodialysis patients, primarily affecting executive function. Risk factors for worse executive function include vascular risk factors as well as vascular disease. Normal performance on the MMSE does not preclude impaired cognitive function, because individuals with MMSE score ≥ 24 also have a high frequency of poor cognitive performance.
authors.affiliation: Division of Nephrology, Tufts Medical Center, Boston, MA, USA. msarnak@tuftsmedicalcenter.org
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Sarnak
authors.forename: Hocine
authors.initials: H
authors.lastname: Tighiouart
authors.forename: Tammy M
authors.initials: TM
authors.lastname: Scott
authors.forename: Kristina V
authors.initials: KV
authors.lastname: Lou
authors.forename: Eric P
authors.initials: EP
authors.lastname: Sorensen
authors.forename: Lena M
authors.initials: LM
authors.lastname: Giang
authors.forename: David A
authors.initials: DA
authors.lastname: Drew
authors.forename: Kamran
authors.initials: K
authors.lastname: Shaffi
authors.forename: James A
authors.initials: JA
authors.lastname: Strom
authors.forename: Ajay K
authors.initials: AK
authors.lastname: Singh
authors.forename: Daniel E
authors.initials: DE
authors.lastname: Weiner
mesh_terms: D000368:Aged; D001900:Boston / Q000453:epidemiology; D003072:Cognition Disorders / Q000453:epidemiology* / Q000209:etiology*; D003430:Cross-Sectional Studies; D056344:Executive Function / Q000502:physiology; D005260:Female; D006801:Humans; D007674:Kidney Diseases / Q000628:therapy; D016014:Linear Models; D008297:Male; D008568:Memory / Q000502:physiology; D008609:Mental Status Schedule; D008875:Middle Aged; D009483:Neuropsychological Tests; D025341:Principal Component Analysis; D012016:Reference Values; D006435:Renal Dialysis / Q000009:adverse effects*; D012307:Risk Factors; D012680:Sensitivity and Specificity