title: Patterns of regional cerebral blood flow associated with low hemoglobin in the Baltimore Longitudinal Study of Aging.
abstract: BACKGROUND
  Anemia has been associated with elevated cerebral blood flow (CBF) in animal models and certain clinical conditions (eg, renal disease), but whether hemoglobin level variations across a relatively normal range are associated with local or diffuse CBF changes is unclear. We investigated whether lower hemoglobin is associated with regional increases in relative CBF in older individuals, and if these increases occur in watershed regions.
  
  
  METHODS
  Seventy-four older nondemented adults underwent serial (15)O water positron emission tomography scans. Voxel-based analysis was used to investigate regional relative CBF patterns in association with hemoglobin level and in individuals with and without anemia. Analyses of cross-sectional relations between regional CBF and anemia were performed separately at two time points, 2 years apart, to identify replicable patterns of associations.
  
  
  RESULTS
  Restricting results to associations replicated across two cross-sectional analyses, lower hemoglobin was associated with higher relative CBF within the middle/inferior frontal, occipital, precuneus, and cerebellar regions. In addition, individuals with anemia (n = 15) showed higher relative CBF in superior frontal, middle temporal, hippocampal, and gyrus rectus regions than those without anemia. In some regions (right superior temporal gyrus, left inferior frontal gyrus, midline cuneus, and right precuneus); however, lower hemoglobin was associated with lower relative CBF.
  
  
  CONCLUSIONS
  In nondemented individuals, lower hemoglobin is associated with elevated relative CBF in specific cortical areas but reduced CBF in other areas. Whether this association between anemia and CBF in the absence of chronic diseases and in a normal physiologic range is related to clinical endpoints warrants further study.
authors.affiliation: Department of Neurology, Johns Hopkins University School of Medicine, Meyer 6-113, 600 North Wolfe Street, Baltimore, MD 21287, USA. rgottesm@jhmi.edu
authors.forename: Rebecca F
authors.initials: RF
authors.lastname: Gottesman
authors.forename: Jitka
authors.initials: J
authors.lastname: Sojkova
authors.forename: Lori L
authors.initials: LL
authors.lastname: Beason-Held
authors.forename: Yang
authors.initials: Y
authors.lastname: An
authors.forename: Dan L
authors.initials: DL
authors.lastname: Longo
authors.forename: Luigi
authors.initials: L
authors.lastname: Ferrucci
authors.forename: Susan M
authors.initials: SM
authors.lastname: Resnick
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000097:blood / Q000502:physiology* / Q000523:psychology; D000740:Anemia / Q000097:blood / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000523:psychology; D015142:Baltimore; D001921:Brain / Q000098:blood supply / Q000000981:diagnostic imaging; D016022:Case-Control Studies; D002560:Cerebrovascular Circulation; D003071:Cognition; D003430:Cross-Sectional Studies; D005260:Female; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography; D012039:Regional Blood Flow
chemical_list: D006454:Hemoglobins