Correlation between long-COVID and physical inactivity

By Neha MathurReviewed by Aimee MolineuxMay 25 2022

In a recent study under review at the Scientific Reports journal and posted to the Research Square* preprint server, researchers assessed whether physical inactivity in coronavirus disease 2019 (COVID-19) survivors led to the development of post-acute sequelae of COVID-19 (PASC), also known as long-COVID.

Study: Association between Post-acute Sequelae of SARS-CoV-2 and Physical Inactivity: A Cohort Study of 614 COVID-19 survivors. Image Credit: eamesBot / Shutterstock

This news article was a review of a preliminary scientific report that had not undergone peer-review at the time of publication. Since its initial publication, the scientific report has now been peer reviewed and accepted for publication in a Scientific Journal. Links to the preliminary and peer-reviewed reports are available in the Sources section at the bottom of this article. View Sources

PASC, the persistence of symptoms, such as fatigue, cough, loss of taste or smell, and impaired cognitive functions, present at least four weeks after the initial severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is common after recovering from COVID-19.

Few studies have demonstrated that those who experience PASC were physically inactive post-SARS-CoV-2 infection relative to the pre-infection period. Therefore, it is crucial to determine how physical inactivity increases the risk of developing PASC in those who survive severe COVID-19.

About the study

The current study invited 749 eligible patients for an in-person visit six to 11 months after being hospitalized for COVID-19 between March and August 2020 in a tertiary hospital in Sao Paulo, Brazil.

A majority of the patients admitted to the hospital intensive care unit (ICU) had pre-existing comorbidities, including hypertension, type 2 diabetes, and obesity. The team classified all the study participants as physically inactive according to the World Health Organization (WHO) guidelines which consider physically active as more than 150 minutes per week of moderate-to-vigorous physical activity.

The researchers used standardized scales to assess ten symptoms of PASC and the international physical activity questionnaire-short form (IPAQ) to determine a patient’s physical activity in the past seven days. Then, they calculated the time spent on each physical activity as the number of days multiplied by self-reported hours.

The researchers stored all the study data from interviews and complementary examinations using web-based case report forms hosted on a Research Electronic Data Capture (REDCap) system. They presented patient characteristics as absolute (n) and relative (%) frequency. They selected confounders based on a direct acyclic graph (DAG) that identified a minimum set of covariates to remove confounding factors.

Study findings

The study included data from 614 patients, 53% of them were male, and the median age of the patients was 56±13 years. Unfortunately, barely 39% of patients met the physical activity recommendations.

The adjusted study model accounted for confounders and showed that patients with one or more PASC symptoms were at greater odds of being physically inactive, with an odds ratio (OR) of 1.56. The number of PASC symptoms was inversely proportional to physical activity. Compared to those with no symptoms, patients with more than five PASC-specific symptoms were at around 133% greater odds of being physically inactive.

Multivariate-adjusted logistic regression analysis (odds ratio [(95% CI]) of the association between presence (panel A) and number of persistent symptoms related to COVID-19 (i.e., none, 1 to 4 and ≥ 5 symptoms) (panel B) with physical inactivity (<150 min/week of moderate-to-vigorous activity). * Indicates P<0.05.

Moreover, 61% of PASC patients showed a higher frequency of physical inactivity, and PASC was related to 56% greater odds of physical inactivity. Specifically, the frequency of physical inactivity in patients with zero, one, one to four, and five or more PASC symptoms was 51%, 62%, 58%, and 71%, respectively. 

Only five specific symptoms, including severe pain in muscles or joints, fatigue, post-trauma stress, insomnia, and dyspnea, increased the odds of physical inactivity, with respective ORs of 1.49, 1.96, 1.53, 1.59, and 2.22. The rest of the symptoms, such as cognitive impairment, depression, anxiety, and loss of smell and taste, were not related to physical inactivity.

Conclusions

The study remarkably demonstrated the correlation between physical inactivity – an emerging cause of morbidity and mortality in COVID-19 patients, and PASC in a group of individuals who survived after being hospitalized for COVID-19. Several patients had physical, mental, and cognitive impairments post six months of acute SARS-CoV-2 infection. The observation that PASC increases the risk of physical inactivity is unique and previously unexplored. Only one other population-based study in Brazil estimated that 47% of individuals of similar age (as the cohort of the present study) were physically inactive versus 61% in the present study.

COVID-19 and PASC can result in persistent physical inactivity and influence patients’ survival. Since different organ dysfunctions augment PASC, future research studies should investigate which ones have the highest impact on physical inactivity related to PASC. In the future, studies should aim at devising methods to reliably identify physical inactivity among survivors of acute SARS-CoV-2 infection and the apparent role of anti-COVID-19 therapies, e.g., vaccination, in preventing physical inactivity. Equally important would be to identify patients that could be specifically targeted for therapies customized to promote physical activity for alleviating the PASC-associated burden.

This news article was a review of a preliminary scientific report that had not undergone peer-review at the time of publication. Since its initial publication, the scientific report has now been peer reviewed and accepted for publication in a Scientific Journal. Links to the preliminary and peer-reviewed reports are available in the Sources section at the bottom of this article. View Sources