Diabetes mellitus as risk factor for atrial fibrillation hospitalization: Incidence and outcomes over nine years in a region of Northern Italy

• Diabetes was confirmed as an independent risk for atrial fibrillation in a large population study.
• Patients with combined diabetes and atrial fibrillation presented the highest risk for stroke and death.
• Oral anticoagulants are under-prescribed in patients with AF, independent of diabetes.

AimsDiabetes mellitus (DM) and atrial fibrillation (AF) are worldwide public health challenges and major causes of death and cardiovascular events. The association between DM and AF is controversial in literature and data on outcomes of individuals with both diseases have not been evaluated in population studies. We tested the hypothesis that DM is independently associated to AF hospitalization and assessed the risk of stroke and mortality in people with both conditions.MethodsWe conducted a population-based cohort-study of DM patients and their corresponding controls identified in a administrative health database of the Lombardy Region. Both cohorts were followed for nine years. A multivariable Cox proportional-hazards-regression model was used to estimate the hazard ratio (HR) for first hospitalization for AF and for clinical outcomes.ResultsOut of 9,061,258 residents, 285,428 (3.14%) DM subjects were identified, mean age 65.8 ± 15 years, 49% were women. The cumulative incidence of AF in DM was 10.4% vs. 7.4% in non-DM. DM was a risk factor for AF (HR 1.32, 95% CI 1.30–1.34; p < 0.0001). Oral anticoagulants were prescribed in 34.8% of DM patients with AF. DM associated with AF, presented the highest HR for stroke: 2.63; 95% CI 2.47–2.80 and for total death, HR 2.41; 95% CI 2.36–2.47.ConclusionsIn this population study, DM was an independent risk factor for AF hospitalization. DM patients with AF had the highest risk of stroke and total mortality. Early identification of AF and a structured plan to optimize the comprehensive management of DM and AF patients is mandatory.