Oxygen Consumption Chronotropic Response to Maximal Exercise and Physical Activity Level in Patients with Post-COVID-19 and Pulmonary İnvolvement

Abstract

Background: Pulmonary involvement due to coronavirus disease 2019 (COVID-19) is common. Pulmonary involvement may affect pulmonary function. Moreover, structural alterations in the lungs may impair the extrapulmonary functions. Purpose: This study compared respiratory functions, peripheral muscle strength, maximal exercise capacity, chronotropic incompetence (CI) (< 80% of maximal heart rate), physical activity level, and dyspnea in patients with post-COVID-19 who had lung involvement and healthy controls. Methods: Forty-seven patients and 60 healthy controls were compared. Pulmonary function (spirometry), respiratory muscle strength (maximal inspiratory-expiratory pressures–MIP, MEP) and endurance, peripheral muscle strength (dynamometry), exercise capacity (cardiopulmonary exercise test–CPET), CI, physical activity(metabolic holter), and dyspnea (modified Borg Scale) were evaluated. Results: Pulmonary function test parameters, MIP, MEP, respiratory muscle endurance, peripheral muscle strength, oxygen consumption, CI during CPET, total and active energy expenditures, daily physical activity duration, metabolic equivalents, and the number of steps were significantly lower in patients compared to controls (p <.001). In contrast, lying down duration (p =.027) and dyspnea on exertion (p <.001) were significantly higher in patients compared with controls. The diffusing capacity for carbon monoxide (DLCO) was 77.2% in patients, indicating mild diffusion impairment. Conclusion: Respiratory functions, peripheral muscle strength, exercise capacity, and chronotropic response are considerably impaired in patients with post-COVID-19 with pulmonary involvement. The majority of patients demonstrate sedentary lifestyle and reported higher levels of dyspnea during daily living activities. Therefore, these outcomes need to be evaluated in patients with pulmonary involvement, and patients should be referred to comprehensive pulmonary rehabilitation to prevent long-term impairments. TRIAL REGISTRATION: NCT05381727–Date: May 17, 2022.