The impact of mild COVID-19 on medium-term respiratory function.
Afr J Thorac Crit Care Med 2024; 30(3):e1629.

Abstract

Background

There is a paucity of evidence on the impact of mild COVID-19 on the respiratory system, particularly in non-healthcare seeking individuals.

Objectives

To investigate the effects of mild COVID-19 on respiratory function and to identify indicators of decreased lung function.

Methods

We conducted a cross-sectional study in 175 non-healthcare-seeking individuals with confirmed acute SARS-CoV-2 infection who did not require hospitalisation. Participants were divided into three groups: those who had pulmonary function tests (PFTs) within 6 months, between 6 and 12 months, and between 12 and 24 months after infection. Each participant underwent spirometry, measurement of the diffusing capacity of the lungs for carbon monoxide (DLCO), a 6-minute walking distance test (6MWD) and plethysmography.

Results

The mean age of the participants was 44.3 years, and the mean body mass index (BMI) 32.7 kg/m[2]. Forty-six participants had PFTs within 6 months, 64 between 6 and 12 months, and 65 between 12 and 24 months. Lower than expected DLCO was the most commonly detected abnormality (57%). Spirometry anomalies were noted in 23%, 10% showing an obstructive impairment and 13% a restrictive impairment, confirmed by a total lung capacity <80%. An increased BMI was the only variable that was significantly and independently linearly associated with lower than predicted (<80%) forced vital capacity, forced expiratory volume in the 1st second, DLCO and 6MWD.

Conclusion

DLCO was low in a considerable proportion of non-healthcare-seeking individuals 2 years after mild COVID-19. A high BMI was found to be significantly and independently associated with lower than predicted PFT results and 6MWD.

Study synopsis

What the study adds. We found that pulmonary function, particularly diffusing capacity, was lower than predicted in a significant proportion of non-healthcare-seeking individuals up to 2 years after mild COVID-19. A high body mass index (BMI) was found to be significantly and independently associated with decreased lung function.Implications of the findings. There is a paucity of evidence on the medium-term effects of mild COVID-19 on the respiratory system in non-healthcare-seeking individuals. We investigated the medium-term effects of mild COVID-19 on the respiratory system, showed lower than predicted lung function, and identified one independent predictor, BMI. Even individuals classified as having 'mild' COVID-19 could have medium-term respiratory sequelae.

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Authors+Show Affiliations

van Heerden J0000-0001-7347-2111Division of Pulmonology, Department of Medicine, Faculty of Medicine and Health Sciences, Stellenbosch University and Tygerberg Hospital, Cape Town, South Africa. Centre for Cardiometabolic Research in Africa, Division of Medical Physiology, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa.
Strijdom HCentre for Cardiometabolic Research in Africa, Division of Medical Physiology, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa.
Parker ADivision of Infectious Diseases, Department of Medicine, Faculty of Medicine and Health Sciences, Stellenbosch University and Tygerberg Hospital, Cape Town, South Africa.
Allwood BWDivision of Pulmonology, Department of Medicine, Faculty of Medicine and Health Sciences, Stellenbosch University and Tygerberg Hospital, Cape Town, South Africa.
Lalla UDivision of Pulmonology, Department of Medicine, Faculty of Medicine and Health Sciences, Stellenbosch University and Tygerberg Hospital, Cape Town, South Africa. Centre for Cardiometabolic Research in Africa, Division of Medical Physiology, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa. Division of Infectious Diseases, Department of Medicine, Faculty of Medicine and Health Sciences, Stellenbosch University and Tygerberg Hospital, Cape Town, South Africa. Division of Epidemiology and Biostatistics, Department of Global Health, Stellenbosch University, Cape Town, South Africa. Biostatistics Unit, South African Medical Research Council, Cape Town, South Africa. Department of Medicine, Faculty of Health Sciences, University of Cape Town, Observatory, South Africa.
Lombard CJDivision of Epidemiology and Biostatistics, Department of Global Health, Stellenbosch University, Cape Town, South Africa. Biostatistics Unit, South African Medical Research Council, Cape Town, South Africa. Department of Medicine, Faculty of Health Sciences, University of Cape Town, Observatory, South Africa.
Koegelenberg CFNDivision of Pulmonology, Department of Medicine, Faculty of Medicine and Health Sciences, Stellenbosch University and Tygerberg Hospital, Cape Town, South Africa.

Pub Type(s)

Journal Article

Language

eng

PubMed ID

39664505