A study of Swiss Army personnel found reduced aerobic capacity in recruits with symptomatic COVID-19 1 to 2 months after diagnosis, researchers at the University of Zurich, Spiez Laboratory, Bern University Hospital, University of Bern and University of Cambridge, reported. The study looked at 199 recruits (median age 21 years) belonging to two companies heavily affected by a COVID-19 outbreak at a Swiss Army base in March and April.
The participants were sorted by infection status into three groups: convalescent recruits with symptomatic COVID-19 (n = 68), asymptomatic recruits with evidence of viral infection (n = 77), and a naïve group without clinical symptoms or evidence of infection (n = 54). The researchers then compared the results of a fitness test – which included an endurance run – conducted a median of 45 days after COVID-19 diagnosis with the results of the same test conducted 3 months before the outbreak.
The comparison revealed that nearly 19% of the COVID-19 convalescents saw a decrease of more than 10% in maximal aerobic capacity (VO2max), while VO2max increased by more than 10% in 14% of the naïve recruits and 8% of the asymptomatic recruits. Prior to the outbreak, VO2max was very similar between the three groups. Strength test results did not differ significantly before and after diagnosis.
The authors of the study note that while the data don't explain the pathophysiology behind the findings, reduced aerobic capacity is a hallmark of interstitial lung disease. "This indicates the importance of further long-term follow-up studies to assess the extent and duration of the sequelae, as well as of infection prevention to avoid these long-term consequences," they wrote.
Abstract
The 2019 coronavirus disease (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged as a pandemic in late 2019, and is ongoing at the time of writing. Long-term sequelae of COVID-19 are still unknown. Pulmonary sequelae impairing physical fitness have been described predominantly for hospitalised patients with COVID-19 [1-3]. Although lung lesions have also been described in asymptomatically infected individuals [3-5], it is yet unclear if these observations correlate with a measurable functional deficit in physical fitness. We performed a well-established and validated physical fitness test [6] before and after an outbreak of COVID-19 among young adult Swiss recruits. By measuring the change in predicted maximal aerobic capacity (VO2 max) of not infected, asymptomatically infected and convalescent COVID-19 individuals, we found a decrease in VO2 max among COVID-19 convalescent but not among asymptomatically and not infected recruits.
Authors
Giovanni Andrea Gerardo Crameri, Michel Bielecki, Roland Züst, Thomas Werner Buehrer, Zeno Stanga, Jeremy Werner Deuel
[link url="https://www.cidrap.umn.edu/news-perspective/2020/09/covid-19-scan-sep-11-2020?utm_campaign=KHN%3A%20Daily%20Health%20Policy%20Report&utm_medium=email&_hsmi=95185376&_hsenc=p2ANqtz-9CXKznZBEWYa_fzXq5D5e73ESiiqx-eNfyde6ZdE1PebNVL1eEhr7uEofionrTfBfa7DeC45R8c7kRufRxRTwdfbY9yw&utm_content=95185376&utm_source=hs_email"]CIDRAP material[/link]
[link url="https://www.eurosurveillance.org/content/10.2807/1560-7917.ES.2020.25.36.2001542#html_fulltext"]Eurosurveillance abstract[/link]