Reduced tidal volume-inflection point and elevated operating lung volumes during exercise in females with well-controlled asthma
Introduction Individuals with asthma breathe at higher operating lung volumes during exercise compared with healthy individuals, which contributes to increased exertional dyspnoea. In health, females are more likely to develop exertional dyspnoea than males at a given workload or ventilation, and th...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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BMJ Publishing Group
2023-11-01
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| Series: | BMJ Open Respiratory Research |
| Online Access: | https://bmjopenrespres.bmj.com/content/10/1/e001791.full |
| _version_ | 1797371361487749120 |
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| author | Michael K Stickland Eric Wong Linn E Moore Andrew R Brotto Devin B Phillips Samira D Rowland |
| author_facet | Michael K Stickland Eric Wong Linn E Moore Andrew R Brotto Devin B Phillips Samira D Rowland |
| author_sort | Michael K Stickland |
| collection | DOAJ |
| description | Introduction Individuals with asthma breathe at higher operating lung volumes during exercise compared with healthy individuals, which contributes to increased exertional dyspnoea. In health, females are more likely to develop exertional dyspnoea than males at a given workload or ventilation, and therefore, it is possible that females with asthma may develop disproportional dyspnoea on exertion. The purpose of this study was to compare operating lung volume and dyspnoea responses during exercise in females with and without asthma.Methods Sixteen female controls and 16 females with asthma were recruited for the study along with 16 male controls and 16 males with asthma as a comparison group. Asthma was confirmed using American Thoracic Society criteria. Participants completed a cycle ergometry cardiopulmonary exercise test to volitional exhaustion. Inspiratory capacity manoeuvres were performed to estimate inspiratory reserve volume (IRV) and dyspnoea was evaluated using the Modified Borg Scale.Results Females with asthma exhibited elevated dyspnoea during submaximal exercise compared with female controls (p<0.05). Females with asthma obtained a similar IRV and dyspnoea at peak exercise compared with healthy females despite lower ventilatory demand, suggesting mechanical constraint to tidal volume (VT) expansion. VT-inflection point was observed at significantly lower ventilation and V̇O2 in females with asthma compared with female controls. Forced expired volume in 1 s was significantly associated with VT-inflection point in females with asthma (R2=0.401; p<0.01) but not female controls (R2=0.002; p=0.88).Conclusion These results suggest that females with asthma are more prone to experience exertional dyspnoea, secondary to dynamic mechanical constraints during submaximal exercise when compared with females without asthma. |
| first_indexed | 2024-03-08T18:18:42Z |
| format | Article |
| id | doaj.art-8e82cd02158d47fa9bc9b617904e03ea |
| institution | Directory Open Access Journal |
| issn | 2052-4439 |
| language | English |
| last_indexed | 2024-03-08T18:18:42Z |
| publishDate | 2023-11-01 |
| publisher | BMJ Publishing Group |
| record_format | Article |
| series | BMJ Open Respiratory Research |
| spelling | doaj.art-8e82cd02158d47fa9bc9b617904e03ea2023-12-31T06:20:08ZengBMJ Publishing GroupBMJ Open Respiratory Research2052-44392023-11-0110110.1136/bmjresp-2023-001791Reduced tidal volume-inflection point and elevated operating lung volumes during exercise in females with well-controlled asthmaMichael K Stickland0Eric Wong1Linn E Moore2Andrew R Brotto3Devin B Phillips4Samira D Rowland53 Division of Pulmonary Medicine, University of Alberta, Edmonton, Alberta, CanadaThames Valley Family Health Team, London, Ontario, CanadaDepartment of Pediatrics, University of Alberta, Edmonton, Alberta, CanadaPulmonary Division, Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, CanadaPulmonary Division, Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, CanadaPulmonary Division, Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, CanadaIntroduction Individuals with asthma breathe at higher operating lung volumes during exercise compared with healthy individuals, which contributes to increased exertional dyspnoea. In health, females are more likely to develop exertional dyspnoea than males at a given workload or ventilation, and therefore, it is possible that females with asthma may develop disproportional dyspnoea on exertion. The purpose of this study was to compare operating lung volume and dyspnoea responses during exercise in females with and without asthma.Methods Sixteen female controls and 16 females with asthma were recruited for the study along with 16 male controls and 16 males with asthma as a comparison group. Asthma was confirmed using American Thoracic Society criteria. Participants completed a cycle ergometry cardiopulmonary exercise test to volitional exhaustion. Inspiratory capacity manoeuvres were performed to estimate inspiratory reserve volume (IRV) and dyspnoea was evaluated using the Modified Borg Scale.Results Females with asthma exhibited elevated dyspnoea during submaximal exercise compared with female controls (p<0.05). Females with asthma obtained a similar IRV and dyspnoea at peak exercise compared with healthy females despite lower ventilatory demand, suggesting mechanical constraint to tidal volume (VT) expansion. VT-inflection point was observed at significantly lower ventilation and V̇O2 in females with asthma compared with female controls. Forced expired volume in 1 s was significantly associated with VT-inflection point in females with asthma (R2=0.401; p<0.01) but not female controls (R2=0.002; p=0.88).Conclusion These results suggest that females with asthma are more prone to experience exertional dyspnoea, secondary to dynamic mechanical constraints during submaximal exercise when compared with females without asthma.https://bmjopenrespres.bmj.com/content/10/1/e001791.full |
| spellingShingle | Michael K Stickland Eric Wong Linn E Moore Andrew R Brotto Devin B Phillips Samira D Rowland Reduced tidal volume-inflection point and elevated operating lung volumes during exercise in females with well-controlled asthma BMJ Open Respiratory Research |
| title | Reduced tidal volume-inflection point and elevated operating lung volumes during exercise in females with well-controlled asthma |
| title_full | Reduced tidal volume-inflection point and elevated operating lung volumes during exercise in females with well-controlled asthma |
| title_fullStr | Reduced tidal volume-inflection point and elevated operating lung volumes during exercise in females with well-controlled asthma |
| title_full_unstemmed | Reduced tidal volume-inflection point and elevated operating lung volumes during exercise in females with well-controlled asthma |
| title_short | Reduced tidal volume-inflection point and elevated operating lung volumes during exercise in females with well-controlled asthma |
| title_sort | reduced tidal volume inflection point and elevated operating lung volumes during exercise in females with well controlled asthma |
| url | https://bmjopenrespres.bmj.com/content/10/1/e001791.full |
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