Introduction SARS-CoV-2 infection may lead to persistent pulmonary sequelae, particularly relevant among workers exposed to occupational stressors such as high altitude. This study aimed to assess the prevalence and associated factors of spirometric alterations in workers with a history of COVID-19 and intermittent exposure to high altitude.

Methods A cross-sectional analytical study was conducted in 400 sea-level-born workers intermittently exposed to altitudes above 2500 meters above sea level, all with a confirmed history of COVID-19. Only spirometry tests rated as quality A or B performed in 2024 were included. Sociodemographic, clinical, and occupational variables were evaluated. Adjusted prevalence ratios (aPR) were estimated using Poisson regression with robust variance.

Results A total of 72.2% of workers showed spirometric abnormalities: 40.5% had a mixed pattern, 20.8% restrictive, and 11.0% obstructive. Independent factors associated with altered spirometry included obesity (aPR: 1.35; 95% CI: 1.19–1.53), high Charlson comorbidity index (aPR: 1.49; 95% CI: 1.33–1.68), prior occupational exposure to harmful substances for over 5 years (aPR: 1.64; 95% CI: 1.43–1.89), intermittent high-altitude exposure ≥7 years (aPR: 1.81; 95% CI: 1.60–2.05), and severe COVID-19 (aPR: 1.65; 95% CI: 1.41–1.91).

Conclusions Over 70% of participants showed spirometric impairment was found in post-COVID-19 workers with intermittent high-altitude exposure. Respiratory function monitoring should be reinforced in this occupational group, especially among those with higher clinical and environmental risk factors.

The authors have declared no competing interest.

The author(s) received no specific funding for this work.

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This study was conducted in accordance with the ethical principles outlined in the Declaration of Helsinki and national regulations for biomedical research. Approval was granted by the Institutional Committee of Ethics in Research (CIEI) of the Universidad Científica del Sur, under official document CONSTANCIA N°670-CIEI-CIENTíFICA-2024. The research protocol was registered with the code POS-60-2024-00841. As this study involved secondary analysis of anonymized data collected during routine occupational health evaluations, individual informed consent was not required. However, all personally identifiable information was protected to ensure strict confidentiality.

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