Obesity in Pediatric Congenital Heart Disease: The Role of Age, Disease Severity, and Sociodemographic Factors

Background: The prevalence of obesity has continued to increase in US pediatric populations. Studies have shown that more than 25% of congenital heart disease (CHD) patients are obese and have increased surgical mortality and decreased cardiac function post-repair. Our study goal was to determine the impact of age, CHD severity, and sociodemographic factors on obesity in children with CHD. We hypothesized that obesity among CHD patients would be more prevalent among children who were older, had simple CHD, and had a lower socioeconomic status.

Methods: We conducted a retrospective review of outpatient electronic medical records in children aged 2-17 years with at least one outpatient visit between 2011 and 2013 from over 50 pediatric clinics in Houston, Texas. We calculated body mass index (BMI); children with age- and sex- specific BMI ≥ 95th percentile were labeled obese. CHD was classified as simple or complex based on Bethesda classifications. Neighborhood poverty was measured by the percentage of children in each Census tract living in poverty. Known correlates of obesity and CHD, including Down syndrome and asthma, were also assessed. Logistic regression was used to determine the association of obesity and CHD while adjusting for age, sex, race/ethnicity, insurance type, CHD severity, and neighborhood poverty level. Finally, an interaction term between age and CHD severity was included to assess the influence of age on the probability of obesity.

Results: We identified 648 CHD (363 simple, 285 complex) and 369,776 non-CHD patients. We found that children with CHD were more likely to be overweight and obese if they were older, male, non-Hispanic Black, Hispanic, publicly insured or uninsured, or have comorbidities of either asthma or Down syndrome (Table). Census tracts with a high percentage of families living in poverty were found to have slightly higher odds of being overweight or obese (OR 1.01; 95% CI 1.01- 1.01). While children with simple CHD had a similar risk of being overweight or obese as non-CHD children, complex CHD patients were much less likely (OR 0.24 (95% CI 0.07- 0.73; p = 0.01). However, as patients aged and by early adolescence, the predicted probability of being obese in patients with complex CHD was found to “catch up” and match that of the general population (Figure).

Conclusion: Obesity impacts CHD populations, most notably patients who are male, minority, publicly insured and those with Down syndrome and asthma. Complex CHD patients have a lower rate of obesity as young children, but rates progressively increase and match that of the general population by age 17. Awareness of the higher risk of obesity as patients age and with specific sociodemographics can assist in earlier identification of patients for healthy lifestyle counseling.