Is lung diffusing capacity lower in expiratory flow limited women compared to non-flow limited women during exercise?

Kali C. Nordin, Michelle J. Lee, Craig A. Harms, J. Richard Coast

Research output: Contribution to journalArticle


Purpose: Women tend to have smaller lungs than men of the same size as well as narrower airways compared to men when matched for the same lung size. Additionally, women with smaller airways relative to lung size are more likely to experience expiratory flow limitation (EFL) as well as exercise-induced arterial hypoxemia (EIAH). One of the possible causes of EIAH includes excessive widening in the alveolar-to-arterial oxygen pressure difference (A-aDO2) due to diffusion limitation. This study investigated if lung diffusing capacity (DLCO) is lower in women with EFL compared to non-flow limited (NEFL) women during exercise. Methods: DLCO was measured using the rebreathing technique at rest and at 40, 60, and 80 % of (Formula presented.) on a treadmill in healthy women with EFL (n = 7; 21.6 ± 2.3) and without EFL (NEFL, n = 9; 21.2 ± 2.3). Arterial oxygen saturation was measured using pulse oximetry (SpO2). Results: There was no difference (p > 0.05) in DLCO between groups at rest or during exercise; however, SpO2 was significantly lower in the EFL females compared to NEFL females during exercise. Conclusion: Due to the lack of differences in DLCO between women with EFL and without EFL, our results suggest that this is not a possible cause for the significant differences in SpO2 between the two groups.

Original languageEnglish (US)
Pages (from-to)755-761
Number of pages7
JournalEuropean Journal of Applied Physiology
Issue number4
StatePublished - Jan 1 2015



  • D
  • EFL
  • Exercise
  • Expiratory flow limitation
  • Females
  • Saturation

ASJC Scopus subject areas

  • Orthopedics and Sports Medicine
  • Public Health, Environmental and Occupational Health
  • Physiology (medical)

Cite this