Abstract 16319: Physical Fitness Modifies the Predictive Impact of Weight Gain and Body Mass Index for Incident Atrial Fibrillation
Introduction: The incidence of both atrial fibrillation (AF) and obesity is increasing in the general population, and lifestyle intervention is recommended. We tested the hypothesis that measured physical fitness modifies the long-term predictive impact of body mass index (BMI) and weight gain since 25 years of age for incident AF.
Methods: From 1972-1975, 2014 healthy middle-aged Norwegian men participating in a prospective cardiovascular survey, underwent a comprehensive clinical examination including a symptom-limited bicycle exercise ECG test. Physical fitness was defined as the total exercise work divided by body weight. During up to 35 years follow-up, 269 men were documented with AF by scrutinizing all hospital discharges. Risk estimation for incident AF was analyzed using Cox proportional hazard models and tested for age-adjusted physical fitness above and below median. All analyses were adjusted for age, systolic blood pressure, current smoking, total cholesterol and blood glucose.
Results: Mean baseline BMI was 24.6 kg/m2 (SD 2.8) and only 24 % of the men had weight gain of 10 kg or more from the age of 25 to midlife, defining this as a lean population. Men with physical fitness below median and BMI >= 28 kg/m2 had a 1.60-fold (95 % CI 1.04-2.41) increased risk of AF compared with men with BMI < 28 kg/m2. Correspondingly, men with physical fitness below median and weight gain >=10 kg had a 3.14-fold (95 % CI 1.14-12.95) risk of AF compared with men with weight loss since 25 years of age. However, among men with above median physical fitness neither weight change nor BMI predicted incident AF.
Conclusions: BMI >= 28 kg/m2 and weight gain >=10 kg since 25 years of age are long-term predictors of incident AF in initially healthy middle-aged men with low physical fitness, but not in physically fit men. High physical fitness reduced the risk of AF associated with BMI and weight gain, and these results might be consistent with the obesity paradox phenomenon where overweight and obese persons have the same favorable outcome as normal weight persons for various cardiovascular events.
- © 2011 by American Heart Association, Inc.