Results:

This review focuses on the implications of childhood obesity for CV risk. Increases in childhood obesity over the past several decades have been observed in both developed and developing countries. The estimated prevalence of childhood obesity has increased by 41.7% since 1980. The greatest increase has been observed in developed countries; however, data from a recent US survey suggest a plateau in the prevalence of childhood overweight and obesity. Measurements of childhood obesity such as percent body fat are limited by lack of access in many parts of the world, while body mass index (BMI) is not accurate in discrimination of lean versus fat mass. Waist circumference and waist-to-height ratio are also associated with risk for CV disease (CVD). Furthermore, definitions vary by society and institution. Which type of measure and what definitions for childhood obesity most accurately predict CV risk is not well understood. Factors associated with CV risk including arterial wall thickness and increased left ventricular mass have been positively associated with BMI in adolescents and young adults. Clustering of CV risk factors including diabetes, hypertension, and dyslipidemia is also observed with increased BMI.

Currently, the ability to estimate the lifetime risk related to obesity in childhood remains limited. Data from observational studies suggest that higher BMI is associated with increased risk for heart disease in adulthood. Data from the Harvard Growth Study, with over 50 years of follow-up, observed 2 times the risk for coronary heart disease among overweight adolescents, irrespective of weight in adulthood. Other studies have observed similar relationships.

It is not clear if interventions to reduce weight among overweight and obese children are associated with long-term reductions in CVD risk. Lifestyle interventions and bariatric surgery among obese adults are associated with improvement in CV risk factors including hypertension and diabetes. Pediatric lifestyle interventions have been associated with improvements in metabolic parameters and measures of endothelial function. Data on use of weight-loss drugs in obese children are limited; metformin has been observed to improve insulin resistance among obese adolescents.

Significant gaps in our current understanding related to the implications of childhood obesity on CVD risk exist. Such knowledge gaps include accurate and easily adoptable methods to measure obesity and CV risk in children, and which measure more accurately predicts future CV risk. Knowledge gaps in best management practices to treat overweight and obese children also exist. The authors of this review recommend large-scale multi-ethnic longitudinal studies, which include children starting from birth to more closely examine the relationship between oversight and obesity with further CV risk.