Purpose: We examined the association between the body mass index analyzed as a continuous variable and by categorization according to World Health Organization criteria (normal weight, overweight and obesity) and the risk of a hospital (inpatient as well as outpatient) diagnosis of atrial fibrillation or flutter.
Methods: Population-based prospective cohort study conducted from December 1993 to December 2001 among 47589 participants (22482 men and 25107 women) without preexisting cardiovascular or endocrine disease and with a mean age at baseline of 56 years (range 50-64 years) in the Danish Diet, Cancer, and Health Study. Subjects were followed up in the Danish National Registry of Patients and in the Danish Civil Registration System.
Results: During follow-up (mean, 5.7 years) atrial fibrillation or flutter developed in 553 subjects (372 men and 181 women). The adjusted hazard ratio for atrial fibrillation or flutter per unit of increase in the body mass index was 1.08 (95% confidence interval [CI]: 1.05 to 1.11) in men and 1.06 (95% CI: 1.03 to 1.09) in women. When using normal weight as a reference, the adjusted hazard ratio for atrial fibrillation or flutter by overweight was 1.75 (95% CI: 1.35 to 2.27) in men and 1.39 (95% CI: 0.99 to 1.94) in women. The adjusted hazard ratio by obesity was 2.35 (95% CI: 1.70 to 3.25) in men and 1.99 (95% CI: 1.31 to 3.02) in women.
Conclusion: Overweight and obesity are associated with an increased risk of a diagnosis of atrial fibrillation or flutter.