OBJECTIVE: Childhood obesity confers an increased risk of vascular changes and adult cardiovascular disease. Using a high-resolution ultrasound technique that enables separation of intimal and medial layers, we examined the intimal thickness (IT) and intimal-medial thickness (IMT) of radial (RA) and dorsal pedal (DPA) arteries and the pulse wave velocity (PWV) in overweight/obese children and adolescents and in healthy subjects. METHODS AND RESULTS: IT and IMT of RA and DPA and PWV were measured in 33 obese children and adolescents (13.9+/-1.6 years) and in 18 matched lean controls (14.3+/-2.2). Increased RA IT was found in the obese group, whereas no differences in RA IMT or medial thickness were observed. Obese females accounted for the entire difference in RA IT (P=0.04). DPA IT was inversely correlated with HDL cholesterol in the obese group (-0.56, P=0.0089). PWV was lower in the obese group than in the lean group (6.2+/-0.8 versus 7.0+/-0.9 m s(-1), respectively; P=0.001). CONCLUSIONS: Obese children and adolescents, primarily females, present with increased RA IT. The decreased PWV in the obese versus lean subjects might reflect general vasodilatation.