Predictors of Increased Carotid Intima-Media Thickness in Youth With Type 1 Diabetes: The SEARCH CVD Study

OBJECTIVE: Youth with type 1 diabetes have worse cardiovascular (CV) risk factors and higher carotid intima-media thickness (IMT) than their peers without diabetes. Whether the burden of CV risk factors over time is associated with carotid IMT at follow-up in youth with type 1 diabetes is not known. RESEARCH DESIGN AND METHODS: Two hundred ninety-eight youth with type 1 diabetes (mean age 13.3 ± 2.9 years, 87.6% non-Hispanic white, 53.7% male) had two study visits 5 years apart. CV risk factors, including BMI, lipids, blood pressure, hemoglobin A(1c), and smoking status, were assessed at both visits, and carotid IMT was measured at follow-up using B-mode ultrasonography. Linear regression models with an area under the curve measurement that incorporated the baseline and follow-up CV risk factors were used to evaluate the relationship with carotid IMT at follow-up. RESULTS: All CV risk factors worsened significantly over time (except LDL cholesterol) (P < 0.05). From baseline to follow-up, the number of abnormal CV risk factors also increased (P < 0.05). Predictors of carotid IMT were older age, male sex, and higher BMI z score area under the curve (all P < 0.05). CONCLUSIONS: The CV risk factor burden increases over time in youth with type 1 diabetes. BMI z score was the only modifiable CV risk factor that predicted carotid IMT. This study highlights the critical need to better understand the risk factors that influence carotid IMT early in the course of type 1 diabetes.