A study by the University of Pennsylvania and researchers from 26 U.S. children's hospitals has linked elevated body mass index (BMI) to a significantly higher risk of developing post-acute sequelae of SARS-CoV-2 infection (PASC) among children and young adults.

The study revealed a 25.4% increased risk of PASC among those with obesity and a 42.1% increased risk among those with severe obesity compared to peers with a healthy BMI.

PASC encompasses a wide range of persistent, relapsing, or newly emerging symptoms that last beyond four weeks after the acute phase of COVID-19. According to the NIH, the most common signs and symptoms are fatigue, shortness of breath, muscle pain, joint pain, headache, cough, chest pain, altered smell, altered taste, and diarrhea.

The study additionally identifies many more symptoms, such as abdominal pain, abnormal liver enzyme levels, acute kidney injury, acute respiratory distress syndrome, arrhythmias, cognitive dysfunction, fever and chills, fluid and electrolyte imbalances, generalized pain, hair loss, heart disease, mental health disorders, myocarditis, myositis, postural orthostatic tachycardia syndrome (POTS) or dysautonomia, skin symptoms, thrombophlebitis, and thromboembolism.

While obesity is known to be associated with increased severity of COVID-19, its relationship with PASC in pediatric populations has been unclear.

In a retrospective cohort study, "Body Mass Index and Postacute Sequelae of SARS-CoV-2 Infection in Children and Young Adults," published in JAMA Network Open, the researchers looked for trends correlating to body mass in PASC.

The team analyzed data from 172,136 participants aged 5 to 20 with documented SARS-CoV-2 infection between March 2020 and May 2023. Participants were categorized based on their BMI status prior to infection: healthy weight, overweight, obesity, and severe obesity.

Results showed that compared with participants with a healthy weight, those with obesity had a 25.4% increased risk of PASC. Those with severe obesity had a 42.1% increased risk when identified using the diagnostic code for post–COVID–19 conditions. An increased risk for any occurrences of PASC symptoms and conditions was also observed among those with obesity and severe obesity.

The researchers concluded that elevated BMI is associated with a significantly increased PASC risk in a dose-dependent manner, highlighting the need for targeted care to prevent chronic conditions in at-risk children and young adults.