Bodyweight fluctuation is associated with increased risk of incident atrial fibrillation.

Background: Obesity and weight gain are established risk factors for atrial fibrillation (AF).
Objective: The purpose of this study was to investigate whether bodyweight variability is also a risk factor for AF development.
Methods: A nationwide population-based cohort of 8,091,401 adults from the Korean National Health Insurance Service database without a history of AF and with ≥3 measurements of bodyweight over a 5-year period were followed up for incident AF. Intraindividual bodyweight variability was calculated using variability independent of mean, and high bodyweight variability was defined as the quartile with the highest variability (Q4) with Q1-Q3 as reference.
Results: During median 8.1 years of follow-up, each increase of 1 SD in bodyweight variability was associated with a 5% increased risk of AF development, and the quartile with the highest bodyweight variability showed 14% increased risk of AF development compared to the quartile with the lowest variability (hazard ratio 1.14; 95% confidence interval 1.12-1.15), after adjustment for baseline bodyweight, height, age, sex, lifestyle factors, and comorbidities. High bodyweight variability was significantly associated with AF development in all baseline body mass index (BMI) groups except the very obese (BMI ≥30), and this association was stronger in subjects with lower bodyweight. High bodyweight variability was associated with increased risk of incident AF in all weight change groups, with a stronger association in those who lost weight.
Conclusion: Bodyweight fluctuation was independently associated with an increased risk of AF development, especially in individuals with low bodyweight, and regardless of weight gain or loss.
(Copyright © 2019 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)