Abstract 15164: Healthy Lifestyle and Heart Rate Variability in the General Population

Abstract

Background: The combined influence of lifestyle factors such as smoking, diet or obesity on heart rate variability (HRV), a measure of autonomic function, is not well studied. We therefore assessed the relationship of a healthy lifestyle score with 24-hour HRV in the general population. Methods: A population-based cohort of healthy individuals aged 25-41 years without prevalent cardiovascular disease was investigated. 24-hour electrocardiography (ECG) was performed with a validated device. All ECG studies were systematically post-processed, and the standard deviation of all normal RR Intervals (SDNN) used as a marker of HRV. Body mass index (BMI) was calculated as body weight (kg) divided by height (meters) squared. Unhealthy lifestyle habits were summed to a lifestyle score with a scale from 0=healthy to 6=unhealthy. One point was given for smoking cigarettes in the past, consuming <5 portions of fruits or vegetables per day, vigorous physical activity <180 minutes per week and a BMI of 25-30kg/m2; two points were given to current smokers and individuals with a BMI ≥30kg/m2. Results: 2140 participants (median age: 37 years, 47% men) were included in this analysis. Mean SDNN values among men and women were 76 and 66ms (p<0.0001), respectively. Main results are shown in the table. Because of a strong sex by lifestyle score interaction (p<0.0001), sex-specific results were evaluated. Most participants had a score between 2 and 3 (Table). In sex-specific multivariable linear regression analysis with SDNN as the outcome variable we found a β (95% confidence interval (CI)) of -4.73 (-5.64; -3.82), p<0.0001 among men and -2.15 (-2.90; -1.40), p<0.0001 among women. Conclusion: Healthy lifestyle was strongly associated with greater HRV in this large sample of young adults, particularly among men. Our findings provide one potential explanation how a healthy lifestyle may lead to better cardiovascular outcomes.