title: The Brain in Kidney Disease (BRINK) Cohort Study: Design and Baseline Cognitive Function.
abstract: BACKGROUND
  The Brain in Kidney Disease (BRINK) Study aims to identify mechanisms that contribute to increased risk for cognitive impairment in patients with chronic kidney disease (CKD). We describe the rationale, design, and methods of the study and report baseline recruitment and cognitive function results.
  
  
  METHODS
  Longitudinal observational cohort study of the epidemiology of cognitive impairment in CKD. The primary aim is to characterize the association between (1) baseline and incident stroke, white matter disease, estimated glomerular filtration rate (eGFR), inflammation, microalbuminuria, and dialysis initiation and (2) cognitive decline over 3 years in a CKD cohort with a mean eGFR<45 mL/min/1.73 m(2).
  
  
  METHODS
  Community-dwelling participants 45 years or older recruited from 4 health systems into 2 groups: reduced eGFR, defined as eGFR<60 mL/min/1.73 m(2) (non-dialysis dependent), and control, defined as eGFR≥60 mL/min/1.73 m(2).
  
  
  METHODS
  eGFR group.
  
  
  RESULTS
  Performance on cognitive function tests and structural brain magnetic resonance imaging.
  
  
  METHODS
  Sequential cognitive and physical function testing, serum and urine biomarker measurement, and brain magnetic resonance images over 3 years.
  
  
  RESULTS
  Of 554 participants, mean age was 69.3 years; 333, 88, and 133 had eGFRs<45 (non-dialysis dependent, nontransplantation), 45 to <60, and ≥60 (controls) mL/min/1.73 m(2), respectively. Mean eGFR in reduced-eGFR participants was 34.3 mL/min/1.73 m(2). Baseline cognitive performance was significantly associated with eGFR in all domains except language. Participants with eGFRs<30 mL/min/1.73 m(2) performed significantly worse than those with eGFRs≥30 mL/min/1.73 m(2) on tests of memory, processing speed, and executive function. Participants with reduced eGFRs overall scored worst on the Immediate Brief Visual-Spatial Memory Test-Revised.
  
  
  CONCLUSIONS
  Healthy cohort bias, competing risk for death versus cognitive decline.
  
  
  CONCLUSIONS
  Cognitive function was significantly worse in participants with eGFRs<30 mL/min/1.73 m(2). Future BRINK analyses will measure risk factors for cognitive decline using the longitudinal data.
authors.affiliation: Berman Center for Clinical Research, Minneapolis Medical Research Foundation, Minneapolis, MN; Geriatrics Division, Hennepin County Medical Center, Minneapolis, MN. Electronic address: amurray@bermancenter.org.
authors.forename: Anne M
authors.initials: AM
authors.lastname: Murray
authors.affiliation: Berman Center for Clinical Research, Minneapolis Medical Research Foundation, Minneapolis, MN.
authors.forename: Elizabeth J
authors.initials: EJ
authors.lastname: Bell
authors.affiliation: Department of Psychology and Neuropsychology, Hennepin County Medical Center, Minneapolis, MN.
authors.forename: David E
authors.initials: DE
authors.lastname: Tupper
authors.affiliation: Biostatistical Design and Analysis Center, University of Minnesota Clinical and Translational Science Institute, Minneapolis, MN.
authors.forename: Cynthia S
authors.initials: CS
authors.lastname: Davey
authors.affiliation: Berman Center for Clinical Research, Minneapolis Medical Research Foundation, Minneapolis, MN.
authors.forename: Sarah L
authors.initials: SL
authors.lastname: Pederson
authors.affiliation: Berman Center for Clinical Research, Minneapolis Medical Research Foundation, Minneapolis, MN.
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Amiot
authors.affiliation: Department of Psychiatry, Hennepin County Medical Center, Minneapolis, MN.
authors.forename: Kathleen M
authors.initials: KM
authors.lastname: Miley
authors.affiliation: University of Minnesota Medical School, Minneapolis, MN.
authors.forename: Lauren
authors.initials: L
authors.lastname: McPherson
authors.affiliation: Chronic Disease Research Group, Minneapolis Medical Research Foundation, Hennepin County Medical Center, Minneapolis, MN.
authors.forename: Brooke M
authors.initials: BM
authors.lastname: Heubner
authors.affiliation: Chronic Disease Research Group, Minneapolis Medical Research Foundation, Hennepin County Medical Center, Minneapolis, MN.
authors.forename: David T
authors.initials: DT
authors.lastname: Gilbertson
authors.affiliation: Nephrology Division, Department of Medicine, University of Minnesota, Minneapolis, MN.
authors.forename: Robert N
authors.initials: RN
authors.lastname: Foley
authors.affiliation: Nephrology Division, Department of Medicine, University of Minnesota, Minneapolis, MN.
authors.forename: Paul E
authors.initials: PE
authors.lastname: Drawz
authors.affiliation: Nephrology Division, Department of Medicine, University of Minnesota, Minneapolis, MN; Veterans Affairs Medical Center, Minneapolis, MN.
authors.forename: Yelena
authors.initials: Y
authors.lastname: Slinin
authors.affiliation: HealthPartners Institute for Education and Research, Minneapolis, MN.
authors.forename: Rebecca C
authors.initials: RC
authors.lastname: Rossom
authors.affiliation: Neurology Department, University of Minnesota, Minneapolis, MN; Division of Epidemiology & Community Health, University of Minnesota School of Public Health, Minneapolis, MN.
authors.forename: Kamakshi
authors.initials: K
authors.lastname: Lakshminarayan
authors.affiliation: Department of Radiology, Mayo Clinic, Rochester, MN.
authors.forename: Prashanthi
authors.initials: P
authors.lastname: Vemuri
authors.affiliation: Department of Radiology, Mayo Clinic, Rochester, MN.
authors.forename: Clifford R
authors.initials: CR
authors.lastname: Jack
authors.affiliation: Department of Neurology, Mayo Clinic, Rochester, MN.
authors.forename: David S
authors.initials: DS
authors.lastname: Knopman
mesh_terms: D000368:Aged; D003071:Cognition; D003072:Cognition Disorders / Q000453:epidemiology / Q000209:etiology*; D015331:Cohort Studies; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011446:Prospective Studies; D051436:Renal Insufficiency, Chronic / Q000150:complications* / Q000503:physiopathology / Q000523:psychology; D012107:Research Design
keywords: Cognitive impairment; attention; brain aging; chronic kidney disease (CKD); estimated glomerular filtration rate (eGFR); executive function; language; memory; neuropsychological testing; processing speed; renal function; stroke; structural brain magnetic resonance imaging; study design