Heart rate variability after bariatric surgery: The add-on value of exercise

Abstract

ABSTRACT Purpose: To assess the impact of bariatric surgery and an added supervised exercise training programme on heart rate variability (HRV) in patients with severe obesity. Methods: Fifty-nine patients who underwent bariatric surgery were randomised in the post-operative period to a 12-week supervised exercise training programme (moderate intensity combination aerobic/resistance exercise training programme) or a control group. Indices of HRV including time-domain, spectral-domain, and nonlinear parameters were measured preoperatively, and at 3, 6, and 12 months. Results: After the surgical procedure, both groups improved anthropometric parameters. Type 2 diabetes, hypertension, and dyslipidemia resolutions were similar between groups. Total body weight loss at 6 and 12 months were also comparable between groups (6 months: 28 ± 6 vs. 30 ± 6%; 12 months: 38 ± 9 vs. 38 ± 10%; control vs. intervention group respectively). Bariatric surgery improved HRV parameters at 12 months compared to the pre-operative values in the intervention group: standard deviation of R-R interval (SDNN) (156.0 ± 46.4 vs. 122.6 ± 33.1 ms), low frequency (LF) (6.3 ± 0.8 vs. 5.8 ± 0.7 ms2), and high frequency (HF) (5.1 ± 0.8 vs. 4.7 ± 0.9 ms2) (all p<0.001). For the control patients, similar improvements in SDNN (150.0 ± 39.4 vs. 118.8 ± 20.1 ms), LF (6.1 ± 0.9 vs. 5.7 ± 0.8 ms2), and HF (5.0 ± 0.9 vs. 4.7 ± 0.9 ms2) were obtained (all p<0.001). However, there was no add-on impact of the supervised exercise training programme on HRV after 12 months (p>0.05 for all HRV parameters). Conclusion: Bariatric surgery is associated with an improvement in HRV. A supervised exercise training programme in the post-operative period did not modulate further the benefits of bariatric surgery regarding HRV parameters. Highlights: Obesity is associated with abnormalities in heart rate variability. Bariatric surgery improves heart rate variability parameters in patients with severe obesity. Due to the substantial weight loss associated with bariatric surgery, a supervised post-operative exercise training programme did not benefit further heart rate variability when compared to bariatric surgery alone.