The study cohort comprised 39 300 men in the Cohort of Swedish Men and 33 090 women in the Swedish Mammography Cohort who were 45–83 years of age and free from atrial fibrillation at baseline. Healthy lifestyle was defined as body mass index < 25 kg/m2, regular exercise for ≥ 20 min/day, no or light-to-moderate alcohol consumption (≤ 2 drinks/day for men and ≤ 1 drink/day for women), and not smoking. Incident AF cases were identified through linkage with the Swedish National Inpatient Register.
During a mean follow-up of 10.9 years, AF occurred in 4028 men and 2539 women. Compared with men and women with no healthy lifestyle factors, the multivariable relative risks (95% confidence interval) of AF were 0.83 (0.65–1.07) for one, 0.74 (0.58–0.94) for two, 0.62 (0.49–0.79) for three, and 0.50 (0.39–0.64) for four healthy lifestyle factors (P for trend < 0.0001). The inverse association was similar in men and women.
Four healthy lifestyle factors combined were associated with a halving of the risk of AF.