INTRODUCTION: The measurement of carotid artery intima-media thickness in children and adolescents has attracted a great deal of research and clinical interest in recent years, because it can provide evidence that early arterial lesions are already present in asymptomatic subjects who have risk factors for cardiovascular disease. The aim of the present study was to investigate possible correlations between parameters of 24-hour ambulatory blood pressure monitoring (ABPM) and carotid artery intima-media thickness in obese and nonobese children and adolescents.METHODS: We studied 128 children and adolescents who were referred for investigation for possible hypertension. All participants in the study underwent ABPM and ultrasound measurement of the intima-media thickness of the common and internal carotid arteries. Obesity was defined as a body mass index (BMI) the 95th percentile for age and sex.RESULTS: Carotid artery intima-media thickness was significantly greater in obese than in non-obese children and adolescents. Linear correlations were observed between common and internal carotid artery intima-media thickness and the BMI percentile, the BMI z score, and parameters from ABPM. Multifactorial analysis of covariance showed that obesity and age were correlated with mean carotid artery intima-media thickness, independently of sex and values of clinic blood pressure and ABPM.CONCLUSIONS: Obese children and adolescents have greater carotid artery intima-media thickness than nonobese subjects, independently of blood pressure. These findings suggest a possible role for childhood obesity in the early onset of carotid artery atherosclerosis.