Effect of activity restriction owing to heart disease on obesity

OBJECTIVE: To determine whether exercise intolerance and recommended activity restrictions are associated with development of overweight and obesity in children with congenital heart disease. DESIGN: Retrospective review. SETTING: Pediatric cardiology practice at a teaching hospital. PARTICIPANTS: A total of 110 pediatric congenital heart disease patients followed up for a mean of 8.4 years. MAIN OUTCOME MEASURES: Body mass index (BMI), sex-appropriate BMI percentiles, overweight (BMI percentile > or =85), and obesity (BMI percentile > or =95) at follow-up. RESULTS: As a group, the increase in BMI percentiles was close to 10 points, but the increase was 21.6 points for exercise intolerant children and 27.3 points for activity restricted children. Activity restriction was significantly associated with both overweight (risk ratio RR], 2.60; 95% confidence interval CI], 1.34-3.54) and obesity at follow-up (RR, 4.08; 95% CI, 1.42-7.38) after adjusting for weight at baseline. For the subset of 92 children at a healthy weight at baseline, activity restriction was again significantly associated with overweight (RR, 2.51; 95% CI, 1.24-3.52) and obesity (RR, 6.14; 95% CI, 2.54-8.82) at follow-up. Exercise intolerance did not attain statistical significance. CONCLUSIONS: Exercise intolerant and activity restricted children experienced larger increases in absolute BMI and BMI percentile than children with neither exercise intolerance nor activity restriction. Activity restriction was the strongest predictor of risk of overweight and obesity at follow-up. Elevated weight and obesity may cause these children significant additional health burdens. Therefore, when patients must be counseled against physical exertion, they also need to be educated about the importance of appropriate physical activity and good dietary practices.