Vagus nerve stimulation increases energy expenditure: relation to brown adipose tissue activity

PLoS One. 2013 Oct 23;8(10):e77221. doi: 10.1371/journal.pone.0077221. eCollection 2013.

Abstract

Background: Human brown adipose tissue (BAT) activity is inversely related to obesity and positively related to energy expenditure. BAT is highly innervated and it is suggested the vagus nerve mediates peripheral signals to the central nervous system, there connecting to sympathetic nerves that innervate BAT. Vagus nerve stimulation (VNS) is used for refractory epilepsy, but is also reported to generate weight loss. We hypothesize VNS increases energy expenditure by activating BAT.

Methods and findings: Fifteen patients with stable vns therapy (age: 45 ± 10 yrs; body mass index; 25.2 ± 3.5 kg/m(2)) were included between January 2011 and June 2012. Ten subjects were measured twice, once with active and once with inactivated VNS. Five other subjects were measured twice, once with active VNS at room temperature and once with active VNS under cold exposure in order to determine maximal cold-induced BAT activity. BAT activity was assessed by 18-Fluoro-Deoxy-Glucose-Positron-Emission-Tomography-and-Computed-Tomography. Basal metabolic rate (BMR) was significantly higher when VNS was turned on (mean change; +2.2%). Mean BAT activity was not significantly different between active VNS and inactive VNS (BAT SUV(Mean); 0.55 ± 0.25 versus 0.67 ± 0.46, P = 0.619). However, the change in energy expenditure upon VNS intervention (On-Off) was significantly correlated to the change in BAT activity (r = 0.935, P<0.001).

Conclusions: VNS significantly increases energy expenditure. The observed change in energy expenditure was significantly related to the change in BAT activity. This suggests a role for BAT in the VNS increase in energy expenditure. Chronic VNS may have a beneficial effect on the human energy balance that has potential application for weight management therapy.

Trial registration: The study was registered in the Clinical Trial Register under the ClinicalTrials.gov Identifier NCT01491282.

Publication types

  • Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adipose Tissue, Brown / metabolism*
  • Adult
  • Analysis of Variance
  • Calorimetry, Indirect
  • Cold Temperature*
  • Energy Metabolism / physiology*
  • Epilepsy / therapy*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Positron-Emission Tomography
  • Vagus Nerve Stimulation*

Associated data

  • ClinicalTrials.gov/NCT01491282

Grant support

This work is part of the research program TOP-subsidies (Netherlands Science Foundation ZonMw, TOP 91209037 to W.D. van Marken Lichtenbelt), which is (partly) financed by the Netherlands Organization for Scientific Research (NWO). Guy H. Vijgen received a Kootstra Talent Fellowship from the Maastricht University Medical Centre that allowed him to perform this study. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.