Background: Patients with Chronic Obstructive Pulmonary Disease (COPD) show ventilatory limitation to exercise due to dynamic hyperinflation (DH). Breathing pattern can be expressed by TI/TTOT (inspiratory time/total time) and VT/TI (tidal volume/inspiratory time). Both parameters significantly increase during exertional hyperpnea in healthy subjects, but they have never been studied in COPD. In a large cohort of COPD patients, we analysed TI/TTOT and VT/TI at rest and during maximal exercise. Methods: We enrolled clinically stable COPD patients with wide degree of airflow obstruction. All participants underwent spirometry and cardiopulmonary exercise testing (CPET) on a cycle ergometer. Results: In 234 COPD patients (75 females; age range 41–89 years), TI/TTOT and VT/TI values significantly increased during exercise, from 0.259 ± 0.040–0.304 ± 0.038 and from 854.1 ± 229,6 ml/s to 2100 ± 622.5 ml/s respectively (p < 0.05). TI/TTOT peak and VT/TI peak were positively related (p < 0.05) with VO2peak (ml/min/kg), maximal workload (Watt). TI/TTOT peak, but not VT/TI peak values showed a positive correlation (p < 0.05) with the peak-rest difference of inspiratory capacity (ΔIC, in ml). When related to minute ventilation TI/TTOT and VT/TI rest values in patients with DH (ΔIC ≥150 ml), compared with those without DH, did not differ between the two groups, though TI/TTOT, but not VT/TI values, significantly increased during exercise in patients without DH Conclusions: TI/TTOT and VT/TI values significantly increase during maximal exercise in COPD. TI/TTOT values were significantly correlated with dynamic hyperinflation. Our results suggest that TI/TTOT and VT/TI assessment may provide further information on exercise ventilatory limitation in COPD.
Breathing pattern and ventilatory response to exercise in patients with Chronic Obstructive Pulmonary Disease / Accogli, R.; Frizzelli, A.; Bondarenko, O.; Tzani, P.; Calzetta, L.; Marchese, A.; Pisi, R.; Caramori, G.; Chetta, A.; Aiello, M.. - In: RESPIRATORY PHYSIOLOGY & NEUROBIOLOGY. - ISSN 1569-9048. - 335:(2025). [10.1016/j.resp.2025.104413]
Breathing pattern and ventilatory response to exercise in patients with Chronic Obstructive Pulmonary Disease
Accogli R.Membro del Collaboration Group
;Frizzelli A.Membro del Collaboration Group
;Bondarenko O.Membro del Collaboration Group
;Tzani P.Membro del Collaboration Group
;Calzetta L.Membro del Collaboration Group
;Pisi R.Membro del Collaboration Group
;Caramori G.Membro del Collaboration Group
;Chetta A.Membro del Collaboration Group
;Aiello M.Membro del Collaboration Group
2025-01-01
Abstract
Background: Patients with Chronic Obstructive Pulmonary Disease (COPD) show ventilatory limitation to exercise due to dynamic hyperinflation (DH). Breathing pattern can be expressed by TI/TTOT (inspiratory time/total time) and VT/TI (tidal volume/inspiratory time). Both parameters significantly increase during exertional hyperpnea in healthy subjects, but they have never been studied in COPD. In a large cohort of COPD patients, we analysed TI/TTOT and VT/TI at rest and during maximal exercise. Methods: We enrolled clinically stable COPD patients with wide degree of airflow obstruction. All participants underwent spirometry and cardiopulmonary exercise testing (CPET) on a cycle ergometer. Results: In 234 COPD patients (75 females; age range 41–89 years), TI/TTOT and VT/TI values significantly increased during exercise, from 0.259 ± 0.040–0.304 ± 0.038 and from 854.1 ± 229,6 ml/s to 2100 ± 622.5 ml/s respectively (p < 0.05). TI/TTOT peak and VT/TI peak were positively related (p < 0.05) with VO2peak (ml/min/kg), maximal workload (Watt). TI/TTOT peak, but not VT/TI peak values showed a positive correlation (p < 0.05) with the peak-rest difference of inspiratory capacity (ΔIC, in ml). When related to minute ventilation TI/TTOT and VT/TI rest values in patients with DH (ΔIC ≥150 ml), compared with those without DH, did not differ between the two groups, though TI/TTOT, but not VT/TI values, significantly increased during exercise in patients without DH Conclusions: TI/TTOT and VT/TI values significantly increase during maximal exercise in COPD. TI/TTOT values were significantly correlated with dynamic hyperinflation. Our results suggest that TI/TTOT and VT/TI assessment may provide further information on exercise ventilatory limitation in COPD.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
