Objectives To measure preclinical noninvasive markers of atherosclerosis in youth with type 1 diabetes (T1DM), and to determine their associations between physical activity level and cardiorespiratory fitness (maximal oxygen consumption [Vo 2 max]). Study design This was a cross-sectional study including 32 patients with T1DM and 42 healthy subjects aged 6 to 17 years. Main outcome measures included arterial flow-mediated dilation (FMD) and intima-media thickness with high-resolution ultrasonography; physical activity by accelerometer (valid 26 patients with T1DM, 35 healthy subjects) and Vo 2 max. Results Compared with healthy control subjects, patients with T1DM had higher intima-media thickness (mean 0.50 mm [0.48-0.52, 95% CI] vs 0.48 [0.47-0.49], P = .02) and reduced FMD (4.9% [4.1%-5.7%] vs 7.3 [6.4-8.1], P = .001), Vo 2 max (45.5 mL/kg/min [43.0-48.0] vs 48.7 [46.7-50.6], P ≤ .001), total (567.1 [458.6-675.6] vs 694.9 [606.6-883.2] counts per minute, P = .001) and moderate-to-vigorous physical activity. Patients with T1DM who did more than 60 min/day −1 of moderate-to-vigorous physical activity had similar FMD compared with relatively inactive healthy subjects, but not as high as active control subjects. Conclusion Youth with T1DM present early signs of atherosclerosis, as well as low physical activity level and cardiorespiratory fitness. Endothelial function is enhanced in patients who practice more than 60 min/day −1 of moderate-to-vigorous physical activity.
