Insulin resistance (IR) and obesity are independently associated with T1D and are known risk factors for CV disease, the leading cause of mortality in T1D. We evaluated the impact of BMI on CV outcomes in T1D youth and compared obese T1D (OT1D) youth to youth with type 2 diabetes (T2D). Pubertal youth aged 12-21 years with T1D and T2D were recruited from the RESistance to InSulin in type 1 and type 2 diabetes (RESISTANT) and Effects of MEtformin on CardiovasculaR Function in AdoLescents with type 1 Diabetes (EMERALD) cohorts. Participants were stratified as lean (LT1D), overweight, or obese T1D or T2D (Table). CV outcomes included resting heart rate (HR), systolic and diastolic blood pressure (SBP, DBP), leptin, hsCRP, and adiponectin. T1D participants performed bicycle ergometry for peak oxygen consumption (VO2peak), brachial artery (BA) distensibility by Dynapulse, and aortic MRI. HR, SBP, DBP, mean arterial pressure, and prevalence of hypertension were higher and BA distensibility, descending aorta oscillatory shear index, VO2peak, leptin, and hsCRP were worsened in OT1D vs. LT1D. Beyond hypertension prevalence in OT1D vs. T2D, which was worse in OT1D, T2D did not differ significantly from OT1D. Higher BMI, which is increasingly prevalent in T1D, is associated with a worsened CV profile in T1D youth, nearly approximating the CV phenotype of T2D youth. Closer attention to lifestyle management in T1D youth is needed to help reduce CV risk. Disclosure K.L. Tommerdahl: None. K.V. Baumgartner: None. P. Bjornstad: Advisory Panel; Self; Horizon, XORTX. Consultant; Self; Bayer US, Boehringer Ingelheim International GmbH, Bristol-Myers Squibb Company. A. Baumgartner: None. L. Pyle: None. J.G. Regensteiner: None. J.E.B. Reusch: Board Member; Self; American Diabetes Association. Other Relationship; Self; Merck & Co., Inc. K.J. Nadeau: None. Funding American Diabetes Association (7-11-CD-08 to K.J.N.); JDRF (11-2010-343); National Institutes of Health (1R56DK088971-01)