Abstract

Objectives: Obesity affects nearly one in five children and is associated with increased risk of premature death. Heart disease may contribute to this premature death. We aimed to use cardiac magnetic resonance (CMR) to comprehensively assess the prevalence and severity of heart disease in obese children, with the hypothesis that obese children have cardiac remodeling and impaired cardiac function compared to healthy weight children.

Methods and Results: Twenty obese (age 12 ± 3 years, 60% female) and 20 healthy weight children (age 13 ± 3 years, 50% female) underwent CMR, including both standard cine imaging and displacement encoded imaging, for a complete assessment of left ventricular (LV) structure and function. After adjusting for age, obese children had a 27% increase in LV mass (p <0.001, Figure 1A) and a 12% increase in LV thickness (obese = 5.5 ± 0.7 mm, healthy = 5.0 ± 0.7 mm, p = 0.01). This evidence of cardiac remodeling was present in obese children as young as age 8. Forty percent of obese children had concentric hypertrophy, 40% had normal geometry and 20% had either eccentric hypertrophy or concentric remodeling. LV ejection fraction and peak strains were not different between the healthy weight and obese groups. However, peak longitudinal strain showed a significant relationship with the type of LV remodeling, and was most impaired in obese children with concentric hypertrophy (Figure 1B).

Conclusions: Obese children show evidence of significant heart disease, which begins as young as age 8. The presence of concentric hypertrophy in 40% of obese children along with the association with impaired cardiac strain in these children may represent a high-risk subgroup. Given the associations between pediatric obesity and early mortality, these early signs of heart disease in obese children demand further investigation.