For children and teenagers, being overweight can mean a higher chance of prolonged COVID-19

A study of 172,136 children and young adults found that higher BMI was associated with an increased risk of PASC: 25.4% higher for obesity and 42.1% higher for severe obesity.

In a cohort study published in JAMA Network Open, Researchers from the United States of America (USA) investigated the relationship between body mass index (BMI) status before coronavirus disease 2019 (COVID-19) and the risk of post-acute sequelae of severe acute respiratory syndrome, coronavirus 2 (SARS-CoV-2) infection (SARS ) in children.

They found that higher BMI, particularly obesity and severe obesity, was associated with an increased risk of PASC, with the risk increasing in a dose-dependent manner relative to BMI.

Background

Pediatric PASC is a complex condition involving persistent, recurrent, or new symptoms that appear at least 4 weeks after an acute illness with COVID-19. Its effects span multiple organ systems, with prevalence estimates ranging from 1.6% to 70% across studies. The disease poses a significant risk to children, highlighting the urgent need to understand its causes, as highlighted by the National Institute for Health and Care Excellence.

Although obesity is a well-known chronic condition associated with severe COVID-19 outcomes even in the US, most studies of obesity-related PASC risk have focused on adults. While some studies have investigated PASC in obese children, the specifics of this relationship, especially its dose-response relationship, remain poorly understood, indicating a critical gap with important implications for pediatric health.

In this study, researchers examined the potential association between pre-infection BMI and PASC outcomes to guide prevention and care in at-risk pediatric patients.

About research

In this retrospective cohort study, researchers used de-identified data from 26 US institutions. They analyzed pediatric COVID-19 outcomes using hospitals and outpatient settings. Data were obtained from electronic health records (EHR) between March 2020 and May 2023 of children under 21 years of age with documented SARS-CoV-2 infection. Participants were excluded if they were less than five years old at the time of BMI assessment or had genetic or medical conditions affecting weight.

A total of 172,136 participants were included. The average age of the participants was 12.6 years at the time of BMI assessment; 52.4% were female and 50.7% were non-Hispanic white. BMI categories were based on growth chart age percentiles provided by the Centers for Disease Control and Prevention, or BMI ranges for adults 19 years of age and older.

PASC was identified using International Classification of Diseases 10 codes^thousand a review of post-COVID conditions and clusters of 24 symptoms and conditions representing the PASC phenotype. Variables such as age, gender, race/ethnicity, variant of COVID-19, health care utilization, comorbidity index, severity of COVID-19, vaccination status, and type of insurance were also included in the study.

The follow-up period ranged from 28 to 179 days after the index date, which was either the earliest date of COVID-19 diagnosis or 28 days before a diagnosis of PASC or multisystem inflammatory syndrome. Statistical analysis involved the use of Poisson and modified Poisson regression, orthogonal trend analysis, and multiple sensitivity analyses.

Results and discussion

About 49.7% of the participants were obese or severely obese. At follow-up, 0.8% of participants were diagnosed with PASC. About 26.4% of participants experienced at least one PASC symptom with similar obesity rates. Participants with a higher BMI demonstrated an increased risk of PASC and PASC-related symptoms compared to those with a relatively lower BMI. A dose-dependent effect was observed. Specifically, obese and severely obese participants showed a higher risk of being diagnosed with PASC (relative risks (RR) were 1.25 and 1.42, respectively) and having any PASC symptoms or conditions (RR 1.11 and 1.17, respectively) .

Subgroup analyzes largely supported these findings, but associations with BMI and PASC were significant only among non-Hispanic white participants and not among non-Hispanic black or Hispanic participants. Sensitivity analysis confirmed the dose-response model. The analysis of the results of the negative control showed no residual error, which indicates the reliability of the results.

This is the first study to examine the association between BMI status and PASC among children, further strengthened by the large sample size. However, the study is limited by potential sampling bias due to high prevalence of obesity, lack of modifiable risk factors such as diet and activity, possible overclassification of PASC without standardized criteria, overlap of symptoms with obesity-related diseases, and selection bias due to overrepresentation of severe cases. despite attempts to include broader ambulatory data.

Conclusion

In conclusion, the study found a strong association between a higher BMI before COVID-19 and an increased risk of PASC in children, emphasizing the need for proactive monitoring and individualized care for those with an elevated BMI. The findings call for public health efforts to promote healthy lifestyle choices and control obesity as a modifiable risk factor to reduce the burden of PASC and improve child health outcomes in the post-pandemic period. Further studies are needed to examine the specific symptoms of PASC associated with BMI.