Sousa GR, et al. - Researchers investigated whether hyperglycemia-induced cardiac autoimmunity could contribute to long-term cardiovascular disease (CVD) complications in people with type 1 diabetes mellitus (T1DM). Using longitudinal samples from the Diabetes Control and Complications Trial (DCCT), they measured the prevalence and profiles of cardiac autoantibodies (AAbs) in participants with mean hemoglobin A1c (HbA1c) ≥ 9.0% (n=83) and ≤7.0% (n=83) during DCCT. A 26-year median follow-up was performed during which subsequent coronary artery calcification, high-sensitivity C-reactive protein, and CVD events were evaluated. Findings revealed an association between poor glycemic control and cardiac autoimmunity in participants with T1DM. Also, a link was observed between cardiac AAb positivity and an increased risk of CVD decades later. Overall, autoimmune mechanisms, possibly via inflammatory pathways, were suggested to have a role in the development of CVD in T1DM.