Methods and Results—To evaluate the reversibility of obesity-related arterial dysfunction and carotid intima-media
thickening by dietary and/or exercise intervention programs, 82 overweight children (body mass index, 253), 9 to 12
years of age, were randomly assigned to dietary modification only or diet plus a supervised structured exercise program
for 6 weeks and subsequently for 1 year. The prospectively defined primary end points were ultrasound-derived arterial
endothelial function (endothelium-dependent dilation) of the brachial artery and intima-media thickness of common
carotid artery. At 6 weeks, both interventions were associated with decreased waist-hip ratio (P0.02) and cholesterol
level (P0.05) as well as improved arterial endothelial function. Diet and exercise together were associated with a
significantly greater improvement in endothelial function than diet alone (P0.01). At 1 year, there was significantly
less thickening of the carotid wall (P0.001) as well as persistent improvements in body fat content and lipid profiles
in the group continuing an exercise program. Vascular function was significantly better in those children continuing
exercise (n22) compared with children who withdrew from the exercise program (n19) (P0.05).
Conclusions—Obesity-related vascular dysfunction in otherwise healthy young children is partially reversible with diet
alone or particularly diet combined with exercise training at 6 weeks, with sustained improvements at 1 year in those
persisting with diet plus regular exercise.