Background—Adults with obesity or type 2 diabetes mellitus (T2DM) are at higher risk for stroke and myocardial infarction. Increased carotid intima-media thickness (cIMT) and stiffness are associated with these adverse outcomes. We compared carotid arteries in youth who were lean, were obese, or had T2DM.

Methods and Results—Carotid ultrasound for cIMT measurement was performed, the Young elastic modulus and beta stiffness index were calculated, and anthropometric and laboratory values and blood pressure were measured in 182 lean, 136 obese, and 128 T2DM youth (aged 10 to 24 years). Mean differences were evaluated by ANOVA. Independent determinants of cIMT, Young elastic modulus, and beta stiffness index were determined with general linear models. Cardiovascular risk factors worsened from lean to obese to T2DM groups. T2DM subjects had greater cIMT than that in lean and obese subjects for the common carotid artery and bulb. For the internal carotid artery, cIMT measurements in both obese and T2DM groups were thicker than in the lean group. The carotid arteries were stiffer in obese and T2DM groups than in the lean group. Determinants of cIMT were group, groupxage interaction, sex, and systolic blood pressure for the common carotid artery (r²=0.17); age, race, and systolic blood pressure for the bulb (r²=0.16); and age, race, sex, systolic blood pressure, and total cholesterol for the internal carotid artery (r²=0.21). Age, systolic blood pressure, and diastolic blood pressure were determinants of all measures of carotid stiffness, with sex adding to the Young elastic modulus (r²=0.23), and body mass index Z score, group, and groupxage interaction contributing to the beta stiffness index (r²=0.31; all P<0.0001).

Conclusions—Youth with obesity and T2DM have abnormalities in carotid thickness and stiffness that are only partially explained by traditional cardiovascular risk factors. These vascular changes should alert healthcare practitioners to address cardiovascular risk factors early to prevent an increase in the incidence of stroke and myocardial infarction.