In a recent study published in Nature’s Scientific Reports, a team of scientists investigated factors such as cardiopulmonary fitness, body composition, and long-term symptoms associated with coronavirus disease 2019 (COVID-19) sequelae in individuals who had recovered from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections.

Study: Body composition and cardiorespiratory fitness of overweight COVID-19 survivors in different severity degrees: a cohort study. Image Credit: Billion Photos/Shutterstock.com

Background

A large body of evidence suggests that COVID-19 is not only a respiratory disease but a multisystem syndrome. Like many other viral diseases, the end of acute SARS-CoV-2 infections is characterized by persistent COVID-19 symptoms that impact the cardiovascular, pulmonary, neurocognitive, muscular, and digestive systems.

These symptoms are collectively known as long coronavirus disease (long COVID) or post-acute sequelae of  COVID-19 (PASC) and can vary significantly across environmental and lifestyle-related factors such as age, ethnicity, sex, comorbidities, and hospitalization factors.

Two broad categories have emerged in the classification of long COVID — one pertaining to the tissue damage that impacts major organs such as lungs, heart, and neurological tissue, and the other related to the chronic inflammation that results in autoimmunity, dysbiosis, viral persistence, and lymphopenia.

Studies have shown that individuals with higher fat mass, neuropathies, myopathies, and lower cardiopulmonary fitness are at increased risk of being admitted to intensive care units due to severe COVID-19.

Therefore, understanding how overweight individuals are impacted by various long COVID symptoms is essential for developing effective treatment and rehabilitation strategies.

About the study

In the present study, the team aimed to evaluate cardiopulmonary fitness, body composition, and persistent long COVID symptoms of individuals who had SARS-CoV-2 infections and compare the symptoms with the severity of the infection. They also examined the hemodynamic and cardiopulmonary recovery after a stress test during the one-year follow-up.

The participants were categorized according to the severity of COVID-19 into mind, moderate, and critically ill or severe, and detailed information about medication use, medical history, hospitalization and respiratory support requirements, and persistent long COVID symptoms was collected.

The test included individuals between the ages of 18 and 65 years who had a positive COVID-19 diagnosis based on a positive reverse transcription polymerase chain reaction (RT-PCR) test.

The participants were also overweight or obese according to their body mass index (BMI). They had to have received at least one dose of the COVID-19 vaccine and be medically cleared to undergo the stress test. Reduced mobility or any disabling neurological disorders were grounds for exclusion.

Baseline assessments included anthropometric and body composition measurements and a Bruce test to determine the systolic and diastolic blood pressures, heart rate, and oxygen saturation. Self-reported medical history, SARS-CoV-2 infection characteristics, lifestyle habits, persistent long COVID symptoms, and physical activity levels were also recorded.

Bioelectrical impedance analysis was used to evaluate body composition measures such as body mass, lean mass, skeletal muscle mass, fat mass, fat-free mass, and body fat, and these values, along with height measurements, were used to calculate the BMI.

An adapted Bruce test was used to monitor vital signs such as heart rate, oxygen saturation, and blood pressure during the stress test. These assessments were repeated after a year.

Results

The results reported that the long-term symptoms most prevalent after COVID-19 in overweight or obese individuals were memory deficits, lack of concentration, fatigue, and dyspnea, in that order.

The Bruce test indicated that oxygen saturation was significantly lower for close to 5 minutes, and the diastolic blood pressure was significantly higher in the critically ill group than in the mild group.

The body composition measures also showed a time effect, with individuals in the critically ill or severe COVID-19 group showing an increase in skeletal muscle mass, lean mass, and fat-free mass after a year.

The cardiopulmonary fitness did not seem to differ significantly across groups, and the respiratory quotient of the critically ill group was higher after a year compared to itself. However, the hemodynamic responses after exercising remained worse in individuals in the critically ill group.

The higher fat mass values in the critical or severe cases compared to the mild cases indicated adiposity, which was attributed to low-grade inflammation.

Given that the prevalence of persistent long-term COVID symptoms was not substantially different across the three groups, the authors believe that a treatment and recovery approach consisting of regular physical activity and balanced nutrition is essential for all long COVID patients.

Conclusions

To summarize, the findings reported that overall cardiopulmonary fitness did not vary significantly based on the severity of COVID-19. Body composition assessments indicated increased adiposity associated with low-grade inflammation in critically ill COVID-19 patients.

However, the prevalence of long COVID symptoms did not vary according to COVID-19 severity, with memory deficits, difficulty concentrating, fatigue, and dyspnea being the most prevalent symptoms.