Association of Severe Obesity, Hypertension, and Physical Activity with 24 h Heart Rate Variability in Adults

Background: Heart rate variability (HRV), the physiological variation between consecutive heartbeats and a non-invasive marker of autonomic regulation, is associated with cardiovascular health. This retrospective cross-sectional study investigated the associations of severe obesity, hypertension, and physical activity with 24 h HRV in patients undergoing evaluation for bariatric surgery. Methods: A total of 1048 individuals were classified according to obesity class, hypertension diagnosis, and physical activity level. Results: Severe obesity was associated with lower 24 h HRV indices (p < 0.001) and higher odds ratio of hypertension (OR 2.04 [1.60-2.63]) and antihypertensive medication use (OR 1.98 [1.53-2.58]) compared to class II obesity. Hypertension was associated with lower HRV indices (p < 0.001), higher odds of diabetes (OR 4.20 [2.88-6.12]) and dyslipidemia (OR 2.85 [2.17-3.74]), greater use of related medications (OR 3.53 [2.18-5.70)] and 2.96 [1.99-4.40]), respectively), and lower physical activity (OR 0.64 [0.47-0.87]). Physical activity was associated with higher 24 h HRV indices (p < 0.001) and lower odds of hypertension (OR 0.64 [0.47-0.87]) and antihypertensive medication use (OR 0.70 [0.50-0.97]). Conclusions: Severe obesity and hypertension were associated with reduced 24 h HRV, whereas physical activity was associated with more favorable HRV parameters in adults undergoing evaluation for bariatric surgery, supporting its relevance for cardiovascular health in this population.