Mentias A, et al. - Researchers evaluated how the risk of stroke and myocardial infarction (MI) in patients with atrial fibrillation (AF) and diabetes may be influenced by insulin use. From 2011 to 2013, Medicare beneficiaries with new AF were identified for study inclusion. The link between AF and time to stroke and MI was evaluated using multivariate Cox regression models. The investigators adjusted for anticoagulant as a time-dependent covariate. Overall, the study sample consisted of 798,592 patients with AF, including 53,212 insulin-requiring diabetics, 250,214 non-insulin requiring diabetics, and 495,166 non-diabetics. From non-diabetics to non-insulin diabetics, an incremental risk of ischemic stroke and MI was evident, with insulin users exhibiting the highest risk. They noted an attenuation of the protective impact of anticoagulation because of insulin use.