Children and young adults with obesity before acute COVID-19 infection face significantly higher risks of some post-infection cardiovascular and gastrointestinal conditions, according to a study published this week in the Journal of Infection.
The retrospective cohort study, led by researchers from the Center for Health AI and Synthesis of Evidence at the University of Pennsylvania, drew on data from the National Institutes of Health’s RECOVER initiative and included 139,320 patients ages 5 to 20 years diagnosed as having COVID from March 2020 to September 2023.
The researchers examined whether body mass index (BMI) measured in the 18 months before infection was associated with new cardiovascular, gastrointestinal, or neuropsychiatric diagnoses one to six months after infection.
Obesity strongly associated with risk of cardiovascular disorders
Among all participants, 53.3% were categorized as having a healthy weight, 13.4% as overweight, 16.0% as obese, and 17.3% as severely obese.
Severe obesity was strongly associated with a greater risk of post-infection cardiovascular disorders. Compared with youth of a healthy weight, those with severe obesity had more than double the risk of any cardiovascular disorder (adjusted relative risk [RR], 2.56; 95% confidence interval [CI], 1.93 to 3.41).
Chest pain was the most common heart-related symptom after COVID infection, occurring in 1.7% of all participants, and it appeared at roughly the same rate regardless of weight—1.8% among those with healthy weight and 1.6% among those with severe obesity.
High blood pressure became more common as body weight increased. Young people with severe obesity had the highest risk (aRR, 3.68; 95% CI, 2.65 to 5.11) compared with those at a healthy weight. Fainting (syncope) showed the opposite pattern, becoming less common as BMI increased.
Looking at heart conditions overall, the risk rose steadily with higher BMI. Compared with healthy-weight participants, those with obesity had almost double the risk of developing any cardiovascular disorder (aRR, 1.80; 95% CI, 1.44 to 2.24), and the risk for those with severe obesity was over 2.5 times higher (aRR, 2.56; 95% CI, 1.93 to 3.41).
“Our findings that higher BMI categories were associated with increased risks of hypertension and overall cardiovascular disorders are consistent with established evidence linking obesity with cardiovascular dysfunction,” write the authors. “Mechanistically, chronic low-grade inflammation, endothelial dysfunction, metabolic dysregulation, and pre-existing insulin and leptin resistance likely amplify SARS-CoV-2-induced cardiovascular stress.”
Severe obesity and greater risk of diarrhea, GERD
Severe obesity was linked to an increased risk of diarrhea (aRR, 1.34; 95% CI, 1.10 to 1.64) and gastroesophageal reflux disease (GERD) (aRR, 1.29; 95% CI, 1.06 to 1.58). The risk of any gastrointestinal disorder also increased across BMI categories.
“Severe obesity was associated with increased risks of diarrhea and GERD, potentially reflecting obesity-driven changes in gut motility, microbiota composition, and intestinal barrier function,” write the researchers. “COVID-19–related disruption of the gut-adipose axis may synergize with pre-existing obesity-related alterations, contributing to persistent gastrointestinal symptoms.”
No clear pattern in COVID–mental illness links
In contrast, the link between COVID infection and post-infection neuropsychiatric outcomes was inconsistent and, in the case of anxiety and depression, inverse. Anxiety disorders were seen less frequently in people with higher BMI, as was major depression.
More broadly, mental illness did not follow a single, clear pattern. Some conditions were less common at higher BMI levels, while others showed no consistent relationship with BMI.
Mental illness did not follow a single, clear pattern. Some conditions were less common at higher BMI levels, while others showed no consistent relationship with BMI.
“The inverse associations observed between higher BMI and certain neuropsychiatric outcomes, including anxiety and depression, is unexpected and should be interpreted with caution,” write the authors, who speculate that social- and health care–related factors may play a role in the link between COVID infection and neuropsychiatric outcomes.
“Individuals with higher BMI frequently experience weight stigma and implicit biases in clinical settings, which may lead to underrecognition or underdocumentation of mental health symptoms,” they write. “Differences in health-seeking behavior, including reluctance to seek care because of internalized stigma or prior negative healthcare experiences, may further contribute [to] underascertainment.”
The study builds on prior evidence linking obesity to severe acute COVID in children, extending those findings to the post–acute-infection phase.
