title: Longitudinal systolic blood pressure characteristics and integrity of white matter tracts in a cohort of very old black and white adults.
abstract: BACKGROUND
  We sought to determine which systolic blood pressure (SBP) characteristics are associated with reduced brain integrity and whether these associations are stronger for white or gray matter. We hypothesized that exposure to higher and variable SBP will be associated with lower structural integrity of both gray and white matter.
  
  
  METHODS
  Neuroimaging, SBP, and cognition were obtained in 311 community-dwelling adults in 2006-2008 (average age = 83 years; 58% women; 40% black). Antihypertensive medications, SBP, and health-related factors were collected from 1997 to 1998 to time of neuroimaging. SBP values obtained from 1997 to 1998 to time of neuroimaging were used to compute mean; pulse pressure; coefficient of variation; and peak, load, and group-based trajectories.
  
  
  RESULTS
  Higher mean SBP was associated with lower white matter integrity in uncinate and superior lateral fasciculi bilaterally, independent of age, stroke history, antihypertensive medication use (odds ratio of having white matter hyperintensities greater than or equal to the median for 10mm Hg of SBP = 10.4, 95% confidence interval = 10.2-10.6, P = 0.0001; standardized beta for fractional anisotropy = -13.54, SE = 4.58, P = 0.003). These neuroimaging markers attenuated the association between higher SBP and lower digit symbol substitution test. Results were similar for trajectories of SBP and stronger for those with previously higher and variable SBP even if SBP was normal at neuroimaging. Results were similar for those without stroke. Associations with gray matter measures were not significant.
  
  
  CONCLUSIONS
  If confirmed, these data suggest a history of higher and variable SBP for very old adults may be useful to alert clinicians to potential lower integrity in selected tracts, whereas cross-sectional SBP measurements may obscure the risk of underlying white matter hyperintensities. Whether lowering and/or stabilizing SBP levels in very old adults without a remarkable cardiovascular history would have neuroprotective effects and reduce dementia risk needs further study.
authors.affiliation: Department of Epidemiology, University of Pittsburgh, Pittsburgh, Pennsylvania; rosanoc@edc.pitt.edu.
authors.forename: Caterina
authors.initials: C
authors.lastname: Rosano
authors.affiliation: Division of General Internal Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania;
authors.forename: Kaleab Z
authors.initials: KZ
authors.lastname: Abebe
authors.affiliation: Department of Psychiatry, University of Pittsburgh, Pittsburgh, Pennsylvania;
authors.forename: Howard J
authors.initials: HJ
authors.lastname: Aizenstein
authors.affiliation: Department of Epidemiology, University of Pittsburgh, Pittsburgh, Pennsylvania;
authors.forename: Robert
authors.initials: R
authors.lastname: Boudreau
authors.affiliation: Department of Psychiatry, University of Pittsburgh, Pittsburgh, Pennsylvania;
authors.forename: J Richard
authors.initials: JR
authors.lastname: Jennings
authors.affiliation: Department of Bioengineeringm University of Pittsburgh, Pittsburgh, Pennsylvania;
authors.forename: Vijay
authors.initials: V
authors.lastname: Venkatraman
authors.affiliation: National Institutes of Health, National Institute on Aging, National Institutes of Health, Bethesda, MD;
authors.forename: Tamara B
authors.initials: TB
authors.lastname: Harris
authors.affiliation: Department of Psychiatry, University of California-San Francisco, San Francisco, California;
authors.forename: Kristine
authors.initials: K
authors.lastname: Yaffe
authors.affiliation: Department of Preventive Medicine, University of Tennessee Health Science Center, Memphis, Tennessee.
authors.forename: Suzanne
authors.initials: S
authors.lastname: Satterfield
authors.affiliation: Department of Epidemiology, University of Pittsburgh, Pittsburgh, Pennsylvania;
authors.forename: Anne B
authors.initials: AB
authors.lastname: Newman
mesh_terms: D000369:Aged, 80 and over; D000959:Antihypertensive Agents / Q000627:therapeutic use; D001794:Blood Pressure; D005260:Female; D066128:Gray Matter / Q000473:pathology*; D006801:Humans; D006973:Hypertension / Q000188:drug therapy / Q000473:pathology*; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male; D066127:White Matter / Q000473:pathology*
chemical_list: D000959:Antihypertensive Agents
keywords: blood pressure; diffusion tensor imaging; hypertension; systolic blood pressure; white matter.