title: Modulation of Renin-Angiotensin System May Slow Conversion from Mild Cognitive Impairment to Alzheimer's Disease.
abstract: OBJECTIVE
  To assess the effect of modulation of the renin-angiotensin system (RAS) on conversion to Alzheimer's disease (AD) and cognitive decline in people with mild cognitive impairment (MCI) and the effect of the permeability of the blood-brain barrier (BBB) and race on the potential relationship between the RAS and AD.
  
  
  METHODS
  Analysis of data from AD centers funded by the National Alzheimer's Coordinating Center, National Institute on Aging.
  
  
  METHODS
  Alzheimer's Disease Centers.
  
  
  METHODS
  Individuals receiving antihypertensive medications who had MCI at baseline and had cognitive assessments on at least two follow-up visits (N = 784; mean age 75 l 48/% male).
  
  
  METHODS
  Conversion to AD and cognitive and functional decline.
  
  
  RESULTS
  Four hundred eighty-eight participants were receiving RAS-acting antihypertensive medications. RAS-acting medication users were less likely to convert to AD (33% vs 40%; P = .04) and had slower decline on the Clinical Dementia Rating Sum of Boxes (CDR-SOB, P = .005) and Digit Span Forward (P = .02) than nonusers. BBB-crossing RAS-acting medications were associated with slower cognitive decline on the CDR-SOB, (P = .009), the Mini-Mental State Examination (MMSE), (P = .001), and the Boston Naming test (P = .002). RAS-acting medications were associated with cognitive benefits more in African Americans than in Caucasians (MMSE, P = .05; category fluency, P = .04; Digit Span Backward, P = .03).
  
  
  CONCLUSIONS
  RAS-acting medication users were less likely to convert to AD. BBB permeability may produce additional cognitive benefit, and African Americans may benefit more from RAS modulation than Caucasians. Results highlight the need for trials investigating RAS modulation during prodromal disease stages.
authors.affiliation: Department of Neurology, School of Public Health, Emory University, Atlanta, Georgia.
authors.forename: Whitney
authors.initials: W
authors.lastname: Wharton
authors.affiliation: Department of Neurology, School of Public Health, Emory University, Atlanta, Georgia.
authors.forename: Felicia C
authors.initials: FC
authors.lastname: Goldstein
authors.affiliation: Department of Medicine, School of Medicine, School of Public Health, Emory University, Atlanta, Georgia.
authors.forename: Liping
authors.initials: L
authors.lastname: Zhao
authors.affiliation: Department of Environmental and Occupational Health, School of Public Health, Emory University, Atlanta, Georgia.
authors.forename: Kyle
authors.initials: K
authors.lastname: Steenland
authors.affiliation: Department of Neurology, School of Public Health, Emory University, Atlanta, Georgia.
authors.forename: Allan I
authors.initials: AI
authors.lastname: Levey
authors.affiliation: Department of Medicine, School of Medicine, School of Public Health, Emory University, Atlanta, Georgia.|Department of Biostatistics and Bioinformatics, School of Public Health, Emory University, Atlanta, Georgia.
authors.forename: Ihab
authors.initials: I
authors.lastname: Hajjar
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000209:etiology*; D000959:Antihypertensive Agents / Q000627:therapeutic use; D001812:Blood-Brain Barrier; D060825:Cognitive Dysfunction / Q000150:complications* / Q000503:physiopathology*; D018450:Disease Progression; D005260:Female; D006801:Humans; D006973:Hypertension / Q000150:complications / Q000188:drug therapy; D008297:Male; D012084:Renin-Angiotensin System; D013997:Time Factors
chemical_list: D000959:Antihypertensive Agents
keywords: Alzheimer's disease; blood pressure; cognition; hypertension; mild cognitive impairment; renin angiotensin system