BACKGROUND AND AIM: Risk of premature atherosclerotic cardiovascular disease (ASCVD) attributable to diabetes is poorly understood. We evaluated the impact of diabetes on future risk of ASCVD in young men and women. METHODS AND RESULTS: Observational cohort study of young adults (ages 30-55 years) without established ASCVD (as of January 1, 2006) who were members of Kaiser Permanente Northern California, an integrated healthcare delivery system. Adjusted demographics (age, race) and traditional risk factors (hypertension, LDL-cholesterol, HDL- C, total cholesterol, smoking). Models were specified to estimate risk ratios (RRs) for incident ASCVD events by diabetes status: no diabetes (reference) versus diabetes with no treatment, with oral hypoglycemic (OH) only and with OH plus insulin. Incident ASCVD events were defined as a composite of nonfatal myocardial infarction, ischemic stroke, or coronary heart disease death through December 31, 2020. In fully adjusted models, individuals with diabetes using insulin exhibited a 5-fold higher risk among women (RR: 5.44
95 % CI: 4.90-6.05) and a 3-fold higher risk among men (RR: 3.13
95 % CI: 2.84-3.45) for incident ASCVD events compared to those without diabetes. CONCLUSIONS: A proactive stance towards ASCVD risk management in young individuals with diabetes, healthcare professionals can help improve the morbidity and mortality associated with this complex interplay of metabolic and cardiovascular disease.