Pulmonary function, diffusing capacity, and forced oscillometry after recovery from COVID-19 in young, healthy, recreationally active men and women

Abstract

Objectives: This study aimed to examine the long-term impact of COVID-19 on pulmonary function (spirometry and forced oscillometry technique, and lung diffusing capacity for carbon monoxide [DL_CO]) in a large group of young, recreationally active adults.

Methods: A total of 71 participants (aged 21 years) who had recovered from a positive COVID-19 infection (COVID⁺) and 55 participants (aged 24 years) who had never tested positive for COVID-19 (COVID^-) performed routine spirometry and DL_CO. Some patients also completed forced oscillometry technique (n = 22 COVID⁺; n = 18 COVID^-).

Results: The ratio of forced expiratory volume in 1 second to forced vital capacity (FEV₁/FVC) and forced expiratory flow between 25% and 75% of FVC (FEF_25-75%) were slightly but significantly lower in patients who were COVID⁺ than those who were COVID^- (FEV₁/FVC = 93.6 ± 8.3 vs 96.9 ± 6.7%-predicted, P = 0.019; FEF_25-75% = 86.0 ± 21.2 vs 94.5 ± 21.1%-predicted, P = 0.015, respectively). There were no associations between any pulmonary function variables or DL_CO and the number of days between COVID-19 infection and testing.

Conclusions: Our findings provide evidence that pulmonary function and DL_CO are largely preserved after recovery from mild COVID-19 in young, healthy, active men and women.

Keywords: COVID19; Forced oscillation testing; Lung diffusing capacity; Lung function tests; Spirometry.

Figure 1a-e

(a) FVC, (b) FEV₁, (c) FEV₁/FVC, (d) FEF_25-75%, (e) DL_CO in patients who were COVID⁻ and COVID⁺. Each data point represents one patient. Red symbols indicate that the value is below the lower limit of normal. DL_CO, lung diffusing capacity for carbon monoxide; FEV₁, forced expiratory volume in 1 second; FEF_25-75%, forced expiratory flow between 25 and 75% FVC; FVC, forced vital capacity.