Progressive Additive Benefits of Prehabilitation and Subsequent Bariatric Surgery on Cardiac Autonomic Regulation as Assessed by Means of a Simple Unitary Composite Index: Preliminary Data from an Observational Study

Obesity is associated with an increased risk of several chronic comorbidities, which may<br> also be determined by dysfunctional autonomic nervous system (ANS). The influence of bariatric<br> surgery (BS) on ANS balance was explored in previous studies, but with high heterogeneity in both<br> the assessment timing and methods employed. In the present observational study, we applied a<br> clinical protocol which considers two subsequent phases. Twenty-nine non-diabetic obese subjects<br> were studied at baseline (T0), after one month of lifestyle modification (prehabilitation) (phase 1-T1),<br> and after eight months following BS (phase 2-T2). ANS regulation was assessed across the three study<br> epochs by means of ANSI, a single composite percent-ranked proxy of autonomic balance, being free<br> of gender and age bias, economical and simple to apply in a clinical setting. The aim of the present<br> study was to investigate the effects of the clinical protocol based on prehabilitation and subsequent<br> BS on the ANS regulation by means of ANSI. Potential intertwined correlations with metabolic<br> parameters were also investigated. Notably, we observed a progressive improvement in ANS control,<br> even by employing ANSI. Moreover, the reduction in the markers of sympathetic overactivity was<br> found to significantly correlate with the amelioration in some metabolic parameters (fasting glucose,<br> insulin levels, and waist circumference), as well as in stress and tiredness perception. In conclusion,<br> this study provides convincing evidence that a unitary proxy of cardiac autonomic regulation (CAR)<br> may reflect the progressive improvement in autonomic regulation following behavioral and surgical<br> interventions in obese patients. Intriguingly, this might contribute to reducing cardiovascular and<br> metabolic risk.