OBJECTIVE - We used speckle tracking echocardiography to study the early changes in left ventricular (LV) torsion in young patients with uncomplicated type 1 diabetes and stress magnetic resonance imaging (MRI) to assess its interrelationships with coronary microangiopathy. RESEARCH DESIGN AND METHODS - We recruited 33 asymptomatic subjects with type 1 diabetes and 32 age-matched healthy control subjects. All subjects underwent echocardiograms. Stress MRIs were performed in 30 subjects (8 healthy control subjects) to compute myocardial perfusion reserve index (MPRI). RESULTS - A significant increase in LV torsion (2 +/- 0.7 vs. 1.4 +/- 0.7 degrees/cm, P <0.05) was identified in longer-term and retinopathy-positive type 1 diabetic subjects (1.9 +/- 0.7 vs. 1.4 +/- 0.7 degrees/cm, P <0.05) as compared with the healthy control subjects. The MPRI was independently associated with increased LV torsion. CONCLUSIONS - We demonstrate that LV torsion is increased in young patients with uncomplicated type I diabetes and that coronary microvascular disease may play a key pathophysiological role in the development of increased LV torsion.