Long-term changes in pulmonary function following recovery from SARS-CoV-2 infection

To evaluate long-term alterations in pulmonary function among individuals who have recovered from SARS-CoV-2 infection and to examine the association between initial disease severity and residual functional impairment. Hypothesis: Individuals recovering from SARS-CoV-2 infection demonstrate persistent abnormalities in lung volumes, airflow, and diffusion capacity ≥12 months after infection, with greater impairment in those who experienced moderate to severe disease. Methods: This observational study included 196 adults aged 18-60 years with documented SARS-CoV-2 PCR positivity at least 12 months prior. Participants with pre-existing chronic pulmonary disease or invasive ventilation were excluded. Pulmonary function testing was performed according to ATS/ERS standards using spirometry, lung volumes, and diffusing capacity measurements (FVC, FEV 1 , FEV 1 /FVC, TLC, RV, and DLCO). Functional capacity was assessed using the 6-minute walk test (6MWT). Pulmonary parameters were compared with pre-COVID values and analyzed according to disease severity. Results: Significant reductions were observed in post-COVID pulmonary function compared to pre-infection values: FVC decreased from 4.04 ± 0.43 L to 3.32 ± 0.51 L, FEV 1 from 3.26 ± 0.37 L to 2.46 ± 0.57 L, TLC from 4.66 ± 0.53 L to 3.02 ± 0.84 L, and DLCO from 8.37 ± 1.11 to 5.71 ± 1.85 mmol/kPa·min (all p < 0.001). Residual volume increased significantly, indicating air trapping. Patients with severe disease demonstrated lower 6-minute walk distance (511.7 ± 23.0 m vs. 577.0 ± 6.2 m, p < 0.0001) and significant exertional oxygen desaturation. Conclusions: Persistent impairments in lung volumes, airflow, diffusion capacity, and exercise tolerance are evident more than one year after SARS-CoV-2 infection, particularly among individuals with severe disease. These findings highlight the need for long-term pulmonary follow-up and functional assessment in post-COVID populations. Funding: None. This abstract was presented at the American Physiology Summit 2026 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.