Transcutaneous auricular vagus nerve stimulation improve autonomic balance and metabolic syndrome

de Moraes TL, Costa FO, Cabral DG, Fernandes DM, Sangaleti CT, Dalboni MA, Motta E Motta J, de Souza LA, Montano N, Irigoyen MC, Brines M, J Tracey K, Pavlov VA, Consolim Colombo FM. Brief periods of transcutaneous auricular vagus nerve stimulation improve autonomic balance and alter circulating monocytes and endothelial cells in patients with metabolic syndrome: a pilot study. Bioelectron Med. 2023 Mar 31;9(1):7. doi: 10.1186/s42234-023-00109-2. PMID: 36998060; PMCID: PMC10064781.

Abstract

Background: There is emerging evidence that the nervous system regulates immune and metabolic alterations mediating Metabolic syndrome (MetS) pathogenesis via the vagus nerve. This study evaluated the effects of transcutaneous auricular vagus nerve stimulation (TAVNS) on key cardiovascular and inflammatory components of MetS.

Methods: We conducted an open label, randomized (2:1), two-arm, parallel-group controlled trial in MetS patients. Subjects in the treatment group (n = 20) received 30 min of TAVNS with a NEMOS® device placed on the cymba conchae of the left ear, once weekly. Patients in the control group (n = 10) received no stimulation. Hemodynamic, heart rate variability (HRV), biochemical parameters, and monocytes, progenitor endothelial cells, circulating endothelial cells, and endothelial micro particles were evaluated at randomization, after the first TAVNS treatment, and again after 8 weeks of follow-up.

Results: An improvement in sympathovagal balance (HRV analysis) was observed after the first TAVNS session. Only patients treated with TAVNS for 8 weeks had a significant decrease in office BP and HR, a further improvement in sympathovagal balance, with a shift of circulating monocytes towards an anti-inflammatory phenotype and endothelial cells to a reparative vascular profile.

Conclusion: These results are of interest for further study of TAVNS as treatment of MetS.

Keywords: Cardiovascular autonomic control; Endothelial dysfunction; Inflammation; Metabolic syndrome; Monocyte; Transcutaneous auricular vagus nerve stimulation.