title: Hemoglobin, hematocrit, and changes in cerebral blood flow: the Second Manifestations of ARTerial disease-Magnetic Resonance study.
abstract: Hemoglobin and hematocrit are important determinants of blood viscosity and arterial oxygen content and may therefore influence cerebral blood flow (CBF). We examined cross-sectional and prospective associations of hemoglobin and hematocrit with CBF in 569 patients with manifest arterial disease (mean age 57 ± 10 years) with available data on magnetic resonance angiography to measure parenchymal CBF. Mean (SD) parenchymal CBF at baseline was 52.3 (9.8) mL/min/100 mL and decreased with 1.5 (11.0) mL/min/100 mL after on average 3.9 years of follow-up. Linear regression analyses showed that greater hemoglobin and hematocrit values were associated with lower baseline parenchymal CBF and more decline in parenchymal CBF over time, independent of cardiovascular risk factors, use of antiplatelet drugs, anticoagulants, or diuretics, and brain measures: adjusted mean differences (95% confidence interval [CI]) in decline in parenchymal CBF between patients in the lower and upper quartiles of hemoglobin and hematocrit were -2.48 (95% CI -3.70 to -1.25) and -3.69 (95% CI -5.45 to -1.94) mL/min/100 mL. Higher hemoglobin and hematocrit were associated with lower baseline parenchymal CBF and a greater decline in parenchymal CBF over time, possibly as a result of physiological compensating mechanisms.
authors.affiliation: Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands; Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Pieternella H
authors.initials: PH
authors.lastname: van der Veen
authors.affiliation: Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands; Department of Gerontology and Geriatrics, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Majon
authors.initials: M
authors.lastname: Muller
authors.affiliation: Image Sciences Institute, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Koen L
authors.initials: KL
authors.lastname: Vincken
authors.affiliation: Department of Vascular Medicine, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Jan
authors.initials: J
authors.lastname: Westerink
authors.affiliation: Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Willem P T M
authors.initials: WP
authors.lastname: Mali
authors.affiliation: Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Yolanda
authors.initials: Y
authors.lastname: van der Graaf
authors.affiliation: Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands. Electronic address: m.geerlings@umcutrecht.nl.
authors.forename: Mirjam I
authors.initials: MI
authors.lastname: Geerlings
mesh_terms: D000368:Aged; D050197:Atherosclerosis / Q000097:blood / Q000175:diagnosis* / Q000503:physiopathology*; D015415:Biomarkers / Q000097:blood; D001809:Blood Viscosity; D002560:Cerebrovascular Circulation; D003430:Cross-Sectional Studies; D005260:Female; D005500:Follow-Up Studies; D006400:Hematocrit; D006454:Hemoglobins / Q000032:analysis*; D006801:Humans; D016014:Linear Models; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood; D011446:Prospective Studies
chemical_list: D015415:Biomarkers; D006454:Hemoglobins; D010100:Oxygen
keywords: Atherosclerosis; Brain imaging; Cerebral blood flow; Hemorheology; Magnetic resonance imaging