Sažetak sa skupa

https://doi.org/10.15836/ccar2019.233

Exercise heart rate recovery in obesity

Lada Bradić ; University of Zagreb School of Medicine, University Hospital Centre Zagreb, Zagreb, Croatia
Martina Lovrić Benčić ; University of Zagreb School of Medicine, University Hospital Centre Zagreb, Zagreb, Croatia
Juraj Jug ; University of Zagreb School of Medicine, Zagreb, Croatia
Martina Matovinović ; University of Zagreb School of Medicine, University Hospital Centre Zagreb, Zagreb, Croatia
Kristina Gašparović ; University of Zagreb School of Medicine, University Hospital Centre Zagreb, Zagreb, Croatia
Rea Levicki ; Požega General County Hospital, Požega, Croatia

Sažetak

Introduction: Obesity is an epidemic that carries significant cardiovascular (CV) burden. Autonomic
dysfunction, characterized by reduced vagal tone and sympathetic overactivity, has been found in diabetes,
hypertension, heart failure, metabolic syndrome, and other conditions. Heart rate decrease after
exercise, or heart rate recovery (HRR) reflects cardiac autonomic activity. Decreased HRR is a powerful
predictor of CV disease, CV and all-cause mortality.1-3
Patients and Methods: A total of 54 obese patients (24% male, 76% female), age 22-66 (mean 47 year),
BMI 29.4-53.3 (mean 40.3 kg/m2), were enrolled in a multidisciplinary weight management program.
Treadmill testing was done initially and after 6-month follow-up. Standard Bruce protocol was used to
assess exercise capacity and passive HRR (15 sec, 3 and 6 min into the recovery period, as per institutional
protocol). Control group was composed of age- and sex-matched non-obese subjects.
Results: Obese subjects had significantly slower HRR (HRR0:15 6.1 vs. 9.1 BPM, HRR3:00 57.8 vs. 66.6
BPM, HRR6:00 63.3 vs. 72.7 BPM; p=0.0216, 0.0006, 0.0004, respectively). Exercise capacity was also significantly
lower in comparison to control (6.7 vs. 8.6 METs; p=0.000001), with reduced exercise time (6.0
vs. 8.2 min; p=0.000001). Sixteen subjects that reached 6-month follow-up lost 5.4 kg on average. Exercise
capacity increased mildly (6.4 to 7.1 METs; NS), as well as total exercise time (5.6 to 6.6 min; NS).
Discussion and Conclusion: Physiological HRR kinetics follows exponential decay function. Rapid first
phase, mediated by vagal reactivation is followed by a gradual HRR decline, dominated by sympathetic
withdrawal. We found significantly slower HRR over different time-points in the obese, which
reflects autonomic imbalance. Functional aerobic capacity was also significantly reduced. Somewhat
improved functional capacity and dynamics of HRR after weight loss did not reach statistical power. To
conclude, we found evidence of significantly impaired cardiac autonomic function in obese subjects,
together with reduced functional capacity. As the study is ongoing, we hope to demonstrate sustained
effect of exercise and diet on autonomic function. Potential benefit on mortality and CV risk reduction
should encourage patients and health care providers to manage obesity more vigorously.

Ključne riječi

obesity; heart rate recovery; autonomic dysfunction.

Hrčak ID:

226702

URI

https://hrcak.srce.hr/226702

Datum izdavanja:

15.10.2019.

Posjeta: 935 *