Dr. Rachel R. Huxley and colleagues at the University of Minnesota, Minneapolis analyzed data from seven prospective cohort studies and four case-control studies involving more than 1.6 million people. During follow-up ranging from three to 44 years, more than 108,000 patients experienced AF. The summary estimate indicated that patients with diabetes had an approximately 40% greater risk of AF compared to unaffected patients (relative risk, 1.39). Abnormalities in glucose and insulin homeostasis could be involved in this increased risk as could long-term inflammation, but the investigators conclude that "the mechanisms that may underpin the relation between diabetes mellitus and AF remain speculative."