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Hypoxic breathing produces more intense hypoxemia in elderly women than in elderly men.
- Source :
- Frontiers in Physiology; 10/26/2022, Vol. 13, p1-9, 9p
- Publication Year :
- 2022
-
Abstract
- Background: Brief hypoxic exposures are increasingly applied as interventions for aging-related conditions. To optimize the therapeutic impact of hypoxia, knowledge of the sex-related differences in physiological responses to hypoxia is essential. This study compared hypoxia-induced hypoxemic responses in elderly men and women. Methods: Seven elderly men (70.3 ± 6.0 years old) and nine women (69.4 ± 5.5 years old) breathed 10% O<subscript>2</subscript> for 5 min while arterial (SaO<subscript>2</subscript>; transcutaneous photoplethysmography) and cerebral tissue O<subscript>2</subscript> saturation (ScO<subscript>2</subscript>; near-infrared spectroscopy), ventilatory frequency, tidal volume, minute-ventilation, and partial pressures of end-tidal O<subscript>2</subscript> (PETO<subscript>2</subscript>) and CO<subscript>2</subscript> (mass spectrometry) were continuously monitored. Cerebral tissue oxygen extraction fraction (OEF) equaled (SaO<subscript>2</subscript>–ScO<subscript>2</subscript>)/SaO<subscript>2</subscript>. Results: During 5 min hypoxia SaO<subscript>2</subscript> fell from 97.0 ± 0.8% to 80.6 ± 4.6% in the men and from 96.3 ± 1.4% to 72.6 ± 4.0% in the women. The slope ΔSaO<subscript>2</subscript>/min was steeper in the women than the men (−4.71 ± 0.96 vs. −3.24 ± 0.76%/min; p = 0.005). Although SaO<subscript>2</subscript> fell twice as sharply per unit decrease in PETO<subscript>2</subscript> in the women than the men (−1.13 ± 0.11 vs. −0.54 ± 0.06%/mmHg; p = 0.003), minute-ventilation per unit hypoxemia increased less appreciably in the women (−0.092 ± 0.014 vs. −0.160 ± 0.021 L/min/%; p = 0.023). OEF fell with hypoxia duration in the women, but remained stable in the men. Conclusion: During 5 min hypoxic breathing, elderly women experience more intense hypoxemia and reduced chemoreflex sensitivity vs. their male counterparts, which may lower OEF stability in women despite augmented O<subscript>2</subscript> dissociation from hemoglobin during hypoxia. These sex-related differences merit attention when implementing brief hypoxic exposures for therapeutic purposes. [ABSTRACT FROM AUTHOR]
- Subjects :
- OLDER women
OLDER men
HYPOXEMIA
RESPIRATION
NEAR infrared spectroscopy
Subjects
Details
- Language :
- English
- ISSN :
- 1664042X
- Volume :
- 13
- Database :
- Complementary Index
- Journal :
- Frontiers in Physiology
- Publication Type :
- Academic Journal
- Accession number :
- 160150952
- Full Text :
- https://doi.org/10.3389/fphys.2022.989635