[Effects of life style intervention on obesity-related vascular dysfunction in children]

To evaluate the reversibility of obesity-related arterial dysfunction and thickening carotid intima-media through dietary and/or exercise intervention programs.

Seventy-eight 9 to 12 year-old overweight children, were randomly assigned to group A: only dietary modification, group B: diet plus a supervised structured exercise program for 6 weeks (SE) and subsequently for 1 year (CE). The prospectively defined primary end points were assessed through 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 improved arterial endothelial function [group A: (6.36 +/- 0.81)% vs. (5.32 +/- 0.84)%, P < 0.01; group B: (7.46 +/- 0.91)% vs. (5.20-0.87)%, P < 0.01]. A combination of diet and exercise were associated with a significantly greater improvement in endothelial function than on diet alone (P < 0.01). At 1 year, there appeared significantly less thickening of the carotid wall in group CE [(0.57 +/- 0.05) mm vs. (0.59 +/- 0.07) mm, P < 0.001]. Compared with children in group SE [(6.38-1.04)% vs. (5.22 +/- 0.96)%, P < 0.05], vascular function appeared significantly better in group CE [(8.29 +/- 0.78)% vs. (5.38 +/- 0.65)%, P < 0.001].

Obesity-related vascular dysfunction in young children was partially reversible with diet alone but more obvious when combined with exercise training for 6 weeks. Sustained improvements at 1 year was seen in those who persisted in diet program plus regular exercise.