title: Frailty and Cognitive Function in Incident Hemodialysis Patients.
abstract: OBJECTIVE
  Patients of all ages undergoing hemodialysis (HD) have a high prevalence of cognitive impairment and worse cognitive function than healthy controls, and those with dementia are at high risk of death. Frailty has been associated with poor cognitive function in older adults without kidney disease. We hypothesized that frailty might also be associated with poor cognitive function in adults of all ages undergoing HD.
  
  
  METHODS
  At HD initiation, 324 adults enrolled (November 2008 to July 2012) in a longitudinal cohort study (Predictors of Arrhythmic and Cardiovascular Risk in ESRD) were classified into three groups (frail, intermediately frail, and nonfrail) based on the Fried frailty phenotype. Global cognitive function (3MS) and speed/attention (Trail Making Tests A and B [TMTA and TMTB, respectively]) were assessed at cohort entry and 1-year follow-up. Associations between frailty and cognitive function (at cohort entry and 1-year follow-up) were evaluated in adjusted (for sex, age, race, body mass index, education, depression and comorbidity at baseline) linear (3MS, TMTA) and Tobit (TMTB) regression models.
  
  
  RESULTS
  At cohort entry, the mean age was 54.8 years (SD 13.3), 56.5% were men, and 72.8% were black. The prevalence of frailty and intermediate frailty were 34.0% and 37.7%, respectively. The mean 3MS was 89.8 (SD 7.6), TMTA was 55.4 (SD 29), and TMTB was 161 (SD 83). Frailty was independently associated with lower cognitive function at cohort entry for all three measures (3MS: -2.4 points; 95% confidence interval [95% CI], -4.2 to -0.5; P=0.01; TMTA: 12.1 seconds; 95% CI, 4.7 to 19.4; P<0.001; and TMTB: 33.2 seconds; 95% CI, 9.9 to 56.4; P=0.01; all tests for trend, P<0.001) and with worse 3MS at 1-year follow-up (-2.8 points; 95% CI, -5.4 to -0.2; P=0.03).
  
  
  CONCLUSIONS
  In adult incident HD patients, frailty is associated with worse cognitive function, particularly global cognitive function (3MS).
authors.affiliation: Departments of Epidemiology and Departments of Surgery and mara@jhu.edu.
authors.forename: Mara A
authors.initials: MA
authors.lastname: McAdams-DeMarco
authors.affiliation: Departments of Epidemiology and.
authors.forename: Jingwen
authors.initials: J
authors.lastname: Tan
authors.affiliation: Departments of Epidemiology and Departments of Surgery and.
authors.forename: Megan L
authors.initials: ML
authors.lastname: Salter
authors.affiliation: Departments of Epidemiology and.
authors.forename: Alden
authors.initials: A
authors.lastname: Gross
authors.affiliation: Biostatistics, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland; Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland;
authors.forename: Lucy A
authors.initials: LA
authors.lastname: Meoni
authors.affiliation: Departments of Epidemiology and Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland; Nephrology Center of Maryland, Baltimore, Maryland;
authors.forename: Bernard G
authors.initials: BG
authors.lastname: Jaar
authors.affiliation: Departments of Epidemiology and.
authors.forename: Wen-Hong Linda
authors.initials: WH
authors.lastname: Kao
authors.affiliation: Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland; Divisions of Nephrology, Hospital for Sick Children and University Health Network, Toronto, Canada; and Departments of Pediatrics and Medicine, University of Toronto, Toronto, Canada.
authors.forename: Rulan S
authors.initials: RS
authors.lastname: Parekh
authors.affiliation: Departments of Epidemiology and Departments of Surgery and.
authors.forename: Dorry L
authors.initials: DL
authors.lastname: Segev
authors.affiliation: Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland;
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Sozio
mesh_terms: D000328:Adult; D000368:Aged; D001288:Attention; D003071:Cognition; D003072:Cognition Disorders / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology / Q000523:psychology*; D005260:Female; D006304:Health Status; D006305:Health Status Indicators; D006801:Humans; D007676:Kidney Failure, Chronic / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology / Q000523:psychology / Q000628:therapy*; D016014:Linear Models; D008137:Longitudinal Studies; D008297:Male; D008396:Maryland / Q000453:epidemiology; D008875:Middle Aged; D015995:Prevalence; D006435:Renal Dialysis / Q000009:adverse effects; D012307:Risk Factors; D013997:Time Factors; D014145:Trail Making Test
keywords: ESRD; african american; black; cognition; dementia; depression; epidemiology and outcomes; frailty; hemodialysis; kidney failure, chronic; renal dialysis