title: Relations of blood pressure and head injury to regional cerebral blood flow.
abstract: Hypertension confers increased risk for cognitive decline, dementia, and cerebrovascular disease. These associations have been attributed, in part, to cerebral hypoperfusion. Here we posit that relations of higher blood pressure to lower levels of cerebral perfusion may be potentiated by a prior head injury. Participants were 87 community-dwelling older adults - 69% men, 90% white, mean age=66.9years, 27.6% with a history of mild traumatic brain injury (mTBI) defined as a loss of consciousness ≤30min resulting from an injury to the head, and free of major medical (other than hypertension), neurological or psychiatric comorbidities. All engaged in clinical assessment of systolic and diastolic blood pressure (SBP, DBP) and single photon emission computed tomography (SPECT). Computerized coding of the SPECT images yielded relative ratios of blood flow in left and right cortical and select subcortical regions. Cerebellum served as the denominator. Sex-stratified multiple regression analyses, adjusted for age, education, race, alcohol consumption, smoking status, and depressive symptomatology, revealed significant interactions of blood pressure and head injury to cerebral blood flow in men only. Specifically, among men with a history of head injury, higher systolic blood pressure was associated with lower levels of perfusion in the left orbital (β=-3.21, p=0.024) and left dorsolateral (β=-2.61, p=0.042) prefrontal cortex, and left temporal cortex (β=-3.36, p=0.014); higher diastolic blood pressure was marginally associated with lower levels of perfusion in the left dorsolateral prefrontal cortex (β=-2.79, p=0.051). Results indicate that men with a history of head injury may be particularly vulnerable to the impact of higher blood pressure on cerebral perfusion in left anterior cortical regions, thus potentially enhancing risk for adverse brain and neurocognitive outcomes.
authors.affiliation: Department of Psychology, University of Maryland, Baltimore County, 1000 Hilltop Circle, MP312, Baltimore, MD 21250, United States. Electronic address: Jk6@umbc.edu.
authors.forename: Jason E
authors.initials: JE
authors.lastname: Kisser
authors.affiliation: Department of Psychology, University of Maryland, Baltimore County, 1000 Hilltop Circle, MP312, Baltimore, MD 21250, United States. Electronic address: allyssaallen@gmail.com.
authors.forename: Allyssa J
authors.initials: AJ
authors.lastname: Allen
authors.affiliation: Baltimore VA Medical Center, VA Maryland Healthcare System, Department of Gerontology (4B189), 10 North Greene Street, Baltimore, MD 21201, United States. Electronic address: lkatzel@grecc.umaryland.edu.
authors.forename: Leslie I
authors.initials: LI
authors.lastname: Katzel
authors.affiliation: Department of Psychology, University of Maryland, Baltimore County, 1000 Hilltop Circle, MP312, Baltimore, MD 21250, United States. Electronic address: carringtonwendell@gmail.com.
authors.forename: Carrington R
authors.initials: CR
authors.lastname: Wendell
authors.affiliation: Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, United States; VA Maryland Healthcare System, Department of Radiology (114), 10 North Greene Street, Baltimore, MD 21201, United States. Electronic address: esiegel@umaryland.edu.
authors.forename: Eliot L
authors.initials: EL
authors.lastname: Siegel
authors.affiliation: SimonMed Imaging, 1433 Keel Drive, Corona del Mar, CA 92625, United States. Electronic address: dlefkowitz@gmail.com.
authors.forename: David
authors.initials: D
authors.lastname: Lefkowitz
authors.affiliation: Department of Psychology, University of Maryland, Baltimore County, 1000 Hilltop Circle, MP312, Baltimore, MD 21250, United States. Electronic address: waldstei@umbc.edu.
authors.forename: Shari R
authors.initials: SR
authors.lastname: Waldstein
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001794:Blood Pressure / Q000502:physiology*; D001795:Blood Pressure Determination; D001921:Brain / Q000098:blood supply / Q000000981:diagnostic imaging / Q000503:physiopathology*; D000070642:Brain Injuries, Traumatic / Q000000981:diagnostic imaging / Q000503:physiopathology*; D001931:Brain Mapping; D002560:Cerebrovascular Circulation / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012727:Sex Characteristics; D015899:Tomography, Emission-Computed, Single-Photon
keywords: Cerebral blood flow; Hypertension; SPECT; Traumatic brain injury