Pulmonary Function Impairments in Long COVID Patients: An Exploratory Analysis

Introduction: Long COVID or post-acute sequelae of SARS-CoV-2 infection (PASC) frequently involves persistent dyspnea and fatigue. Prior studies highlight diffusion impairment and restrictive ventilatory defects. This exploratory analysis evaluates pulmonary function changes in Long COVID patients stratified by age and sex using the CORSAAR clinical dataset. Methods: We analyzed anonymized pulmonary function data from 293 confirmed Long COVID patients (179 women, 114 men; age 17–83 years; mean age 48.4 years). Parameters included FEV₁, DLCO, KCO, VC, and TLC. Non-parametric approaches (Shapiro-Wilk test confirmed non-normal distribution) were applied. Group comparisons by age categories ( 60 years showed a−16.47 % decline vs.−6.31 % in men. Elderly men experienced statistically significant reductions in FEV₁, VC, and TLC – consistent with restrictive ventilatory changes. KCO varied widely across age groups, suggesting heterogeneity in alveolar-capillary recovery. Notably, some patients < 30 years, with no prior respiratory history, demonstrated abnormal lung function as statistical outliers. Conclusions: Long COVID is associated with chronic pulmonary abnormalities, especially diffusion derangements and restrictive patterns, that vary by age and sex. Older adults and women appear disproportionately affected in diffusion metrics, while young patients may still display impaired values despite no known baseline lung disease. These findings underscore the need for tailored pulmonary surveillance and rehabilitation strategies aligned with patient demographics. Acknowledgements: We thank the CORSAAR study participants and team for their contributions. Publication History Article published online: 04 March 2026 © 2026. Thieme. All rights reserved. Georg Thieme Verlag KG Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany