Blood flow regulation better in elderly women than men
MedWire News: Elderly women regulate brain blood flow better than do elderly men, researchers report.
The team found that elderly women were better able to maintain cerebral blood flow velocities during postural changes and demonstrated better cerebral autoregulation, so that cerebral blood flow remained relatively more constant over a wide range of blood pressures.
The findings come from 544 individuals, 236 of whom were men, who took part in the Maintenance of Balance, Independent Living, Intellect, and Zest in the Elderly of Boston (MOBILIZE Boston) study.
The participants, who were all older than 70 years of age, underwent transcranial Doppler testing as part of MOBILIZE Boston, which was designed to improve understanding of how older adults can maintain their health and independence for longer.
Individuals were assessed for carbon dioxide (CO2) reactivity and transfer function gain, phase, and coherence during 5 minutes of quiet sitting, as well as autoregulatory index during sit-to-stand tests.
Men had significantly lower mean CO2 reactivity than women, at 1.10 versus 1.32 cm/s/%CO2, respectively, and also lower mean autoregulatory indices during a sit-to-stand maneuver, at 4.41 versus 5.32.
Men had significantly higher mean transfer function gain in cerebral autoregulation indices, at 1.34 versus 1.19, and significantly lower phase, at 42.7 versus 49.4, in the autoregulatory band implying less effective cerebral autoregulation.
Higher rates of diabetes in men did not affect the outcome of this study, and their reduced autoregulation was not below the normal range, indicating this was intact but less effective.
Reporting in the journal Stroke, Jorge Serrador (Veterans Affairs New Jersey Health Care System, East Orange, USA) and colleagues conclude: "Future work is needed to examine gender differences in various cerebral arterial beds to better understand these underlying autoregulatory differences."
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By Anita Wilkinson