Increased intima media thickness at many arterial sites in obese adolescents with abdominal adiposity, insulin resistance, and high LDL-cholesterol.

Aim of the present case-control study was to investigate for the first time intima media thickness (IMT) at different arterial sites in two homogeneous study populations of either obese or normal weight age-matched healthy adolescents. Both study populations (Group A and B) consisted of 16 healthy adolescents who had completed pubertal development, had attained final height and were receiving no medications. Group A included 7 boys and 9 girls with no associated disorders, mean age 15.1 ± 0.6 and were recruited from our outpatient clinic for obese children and adolescents (average BMI 35.6 ± 6.3). Group B included 7 boys and 9 girls with normal BMI (mean 21.8 ± 1.7) and mean age 16.0 ± 1.1. BMI, BMI SDS, waist/height ratio, LDL cholesterol and IR index were all significantly higher in Group A, whereas BP, total cholesterol, triglycerides and triglyceride / HDL ratio were not different in the two groups and HDL cholesterol was slightly lower in Group A. All these adolescents underwent an echo color Doppler ustrasonography (US) for measurement of IMT at abdominal aorta, right and left common carotids, right and left carotid bulbs and right and left common femoral arteries. IMT at all the investigated sites was significantly higher in Group A. IMT at all the investigated sites was significantly higher in Group A, even though the highest level of significance was recorded at common carotids followed by carotid bulbs and then common femorals and abdominal aorta (Table2). In the entire study population IMT at common carotids was positively correlated with BMI SDS, waist / height ratio, LDL cholesterol and triglycerides / HDL ratio, whilst the relationship with HDL cholesterol was negative (Table 1). At stepwise regression analysis common carotid IMT was significantly correlated with triglycerides / HDL cholesterol ratio (r = 0.553, p = 0.0001), waist / height ratio (r = 0.412, p = 0.012) and HDL cholesterol (r = -0.309, p = 0.05), whereas no relationships were detected with chronological age, BMI SDS, mean BP, total and LDL cholesterol, triglycerides and IR. The results of the present study confirm that obese patients are at higher risk of developing vascular alterations, as revealed by the increased IMT found in both elastic (common carotids, carotid bulbs, abdominal aorta) and muscular arteries (common femorals), not only at common carotid level. The very significant arterial alterations that we have found at all these vascular sites become evident even in adolescents, although only in a preclinical form, with no significant impact on BP. As increased IMT is an independent predictor of vascular events we can confirm that obese adolescents are at higher risk of developing over time coronary, cerebrovascular and peripheral vascular disease. According to our results common carotid is the most reliable site for an early detection of subclinical atherosclerosis in obese adolescents. However, it is to be considered that the ours is a selected study population consisting of only pubertal subjects with adult height and bone age and, therefore, we cannot exclude that aorta might be a preferable site for imaging subclinical atherosclerotic lesions in younger and prepubertal individuals (9,10). Among all the considered clinical and metabolic parameters, the one that exhibited the most relevant relationship with common carotid IMT was triglycerides / HDL cholesterol ratio, followed by waist / height ratio.