Sex differences in respiratory and circulatory cost during hypoxic walking: potential impact on oxygen saturation.

Journal Article (Journal Article)

Energy expenditure (EE) during treadmill walking under normal conditions (normobaric normoxia, 21% O2 ) and moderate hypoxia (13% O2 ) was measured. Ten healthy young men and ten healthy young women walked on a level (0°) gradient a range of speeds (0.67-1.67 m s-1 ). During walking, there were no significant differences in reductions in arterial oxygen saturation (SpO2 ) between the sexes. The hypoxia-induced increase in EE, heart rate (HR [bpm]) and ventilation ([Formula: see text] [L min-1 ]) were calculated. Using a multivariate model that combined EE, [Formula: see text], and HR to predict ΔSpO2 (hypoxia-induced reduction), a very strong fit model both for men (r2  = 0.900, P < 0.001) and for women was obtained (r2  = 0.957, P < 0.001). The contributions of EE, VE, and HR to ΔSpO2 were markedly different between men and women. [Formula: see text] and EE had a stronger effect on ΔSpO2 in women ([Formula: see text]: 4.1% in women vs. 1.7% in men; EE: 28.1% in women vs. 15.8% in men), while HR had a greater effect in men (82.5% in men and 67.9% in women). These findings suggested that high-altitude adaptation in response to hypoxemia has different underlying mechanisms between men and women. These results can help to explain how to adapt high-altitude for men and women, respectively.

Full Text

Duke Authors

Cited Authors

  • Horiuchi, M; Kirihara, Y; Fukuoka, Y; Pontzer, H

Published Date

  • July 2019

Published In

Volume / Issue

  • 9 / 1

Start / End Page

  • 9550 -

PubMed ID

  • 31266961

Pubmed Central ID

  • PMC6606641

Electronic International Standard Serial Number (EISSN)

  • 2045-2322

International Standard Serial Number (ISSN)

  • 2045-2322

Digital Object Identifier (DOI)

  • 10.1038/s41598-019-44844-6


  • eng