Obesity May Raise Risk of Long COVID in Youth

Elevated body mass index (BMI) in children and young adults was associated with an increased risk of post-acute sequelae of SARS-CoV-2 infection (PASC), or long COVID, a large retrospective cohort study suggested.

Those with obesity had a 25.4% increased risk of long COVID (relative risk [RR] 1.25, 95% CI 1.06-1.48) and those with severe obesity had a 42.1% increased risk (RR 1.42, 95% CI 1.25-1.61) compared with children and young adults who had healthy weight, reported Yong Chen, PhD, of the University of Pennsylvania in Philadelphia, and colleagues.

Similarly, there was an increased likelihood of encountering any manifestation of potential long COVID symptoms and conditions among those with obesity (RR 1.11, 95% CI 1.06-1.15) and severe obesity (RR 1.17, 95% CI 1.14-1.21), they said in JAMA Network Open.

“To our knowledge, this retrospective cohort study is the first and the largest to explore the association of BMI status with PASC among the pediatric population,” Chen and co-authors wrote. “The findings suggest that PASC may lead to poorer long-term quality of life, affecting physical health, educational achievement, and social development; this underscores the importance of early identification, prevention, and targeted interventions to mitigate these risks.”

The prevalence of pediatric cases of long COVID after SARS-CoV-2 infection has varied across studies, with rates ranging from 1.6% to 70%, Chen and colleagues wrote. Obesity is now one of the most common chronic conditions in the U.S., and the association of obesity with increased risk of long COVID has been widely discussed, though mostly focused on adults.

Though some studies have looked at pediatric populations — including obesity as a risk factor — the association with BMI with long COVID in children remains less studied than in adults. Addressing this research gap is crucial in light of the potential long-term outcomes, the researchers said.

Regarding the likelihood of encountering long COVID symptoms, Chen and colleagues reported that the association among participants became slightly more pronounced when assessing the cumulative occurrences of symptoms and conditions among those who had overweight (RR 1.05, 95% CI 1.00-1.11), obesity (RR 1.14, 95% CI 1.09-1.19), and severe obesity (RR 1.18, 95% CI 1.14-1.22).

“There was a significant dose-response association of increasing BMI category with risk of PASC,” they noted.

During the follow-up period, 0.8% of participants received a diagnosis of long COVID, and of these individuals, 53.6% had obesity or severe obesity. Additionally, 26.4% had at least one incident occurrence of long COVID symptoms and conditions, and of these individuals, 52.8% had obesity or severe obesity.

The median time from index date to outcomes for these groups was 50 days and 63 days, respectively, they added. The median total number of incident occurrences of long COVID symptoms and conditions was 0, “signifying that at least one-half of the participants in the cohort did not experience any incident occurrences of PASC symptoms and conditions.”

For the study, 172,136 participants ages 5 to 20 were sourced from 26 children’s hospitals in the U.S. between March 2020 and May 2023, with a minimum follow-up of 179 days.

The mean age at BMI assessment was 12.6 years, and the mean age at study entry was 13.1 years. Slightly more than half of participants were female. About half identified as non-Hispanic white, one-quarter as Hispanic, and about one-fifth as non-Hispanic Black. The median time from BMI status assessment to COVID-19 infection was 4.1 months. About half of participants had obesity or severe obesity.

Study limitations included a high obesity prevalence that may have skewed the sample, and an absence of information on modifiable risk factors, such as diet and physical activity, which may reduce risk, Chen and colleagues noted.

There was also potential for over-classification in pediatric long COVID diagnosis due to a lack of standardized criteria, and selection bias was a concern “particularly if children with higher BMI are more likely to be hospitalized, potentially leading to an overrepresentation of severe cases.”