Comparison of Pulmonary Functions After Induction of Stress Between Post-COVID and Healthy Adults

Since the emergence of COVID in 2019, it has spread worldwide. COVID has affected all the systems of the human body. The present research aimed to assess the effects of COVID-19 on the pulmonary system after stress induction. Healthy and affected individuals between the age of 18 and 40 years were made to perform the 6-minute walk test and their pulmonary functions were compared before and after the stressor. Individuals who were three months post-COVID-19 infection were included as cases. Healthy individuals with no history of COVID were included as controls. The pulmonary functions were performed and noted both at baseline and after the 6-minute walk test. The forced expiratory flow 25 (FEF 25) and peak expiratory flow (PEF) showed statistical significance between both groups (p=0.033 and p=0.007, respectively). FEF 25, 50, and 75, maximum voluntary ventilation (MVV) index, and PEF were positively correlated with all respiratory parameters. Forced expiratory volume % (FEV%) was negatively correlated with vital capacity (VC) and forced vital capacity (FVC). This research helped us establish that the effect on the lungs due to COVID is not due to airway restriction or obstruction but reduced lung volume.