Larger Body Size in Women Increases Risk of Atrial Fibrillation
Catherine Amey, Senior Medical Writer, Touch Medical Media, Reading, UK

Obesity is a known risk factor for atrial fibrillation,1 and large body size and tallness have been associated with increased risk of atrial fibrillation in men,2 however, this has not been investigated in women. To address this, a new, large-scale Swedish study, presented at EuroPrevent 2017, the annual congress of the European Association of Preventive Cardiology, has investigated the association between body surface area (BSA) and atrial fibrillation risk.3 In this study of 1,493,584 women, a larger body size was stepwise associated with an increased risk of atrial fibrillation in women up to 32 years after first childbirth.

The researchers divided the women into four groups based on their BSA: those with a BSA of between 0.97 and 1.61 m2, those with a BSA between 1.61 and 1.71 m2, with a BSA of 1.71–1.82 m2, and finally, those with a BSA of 1.82–3.02 m2. The risk of atrial fibrillation increased by BSA with a hazard ratio of 1.27 (95% confidence intervals [CI] 1.18–1.37), 1.66 (95% CI 1.54–1.79), and 2.89 (95% CI 2.69–3.11) when comparing the highest with the lowest quartile after adjustment for age at first pregnancy, diabetes, hypertension, and smoking.

‘Atrial fibrillation is the result of obesity-related metabolic changes, but there is also a second cause. People with a bigger atrium have a higher risk of atrial fibrillation,’ explained Annika Rosengren, co-author of the study and professor of internal medicine at the Sahlgrenska Academy of the University of Gothenburg in Sweden.

Data on atrial fibrillation-related hospital admissions were accessed from the Swedish Inpatient Registry. In total, 6,270 women (0.4%) were found to have been hospitalised with atrial fibrillation during a maximum follow-up of 32.6 years (mean 15.8, 95% CI 15.8–15.9 years).

1. Cheng TO, Obesity as a risk factor for atrial fibrillation, Int J Cardiol, 2007;114:145.
2. Rosengren A, Hauptman PJ, Lappas G, et al., Big men and atrial fibrillation: effects of body size and weight gain on risk of atrial fibrillation in men, Eur Heart J, 2009;30:1113–20.
3. Persson CE, Adiels M, Bjorck et al., Body size and risk of atrial fibrillation in women - a registry-based cohort study, Presented at: EuroPrevent 2017, Malaga, Spain, 6–8 April 2017.