Does vagal nerve stimulation affect body composition and metabolism? Experimental study of a new potential technique in bariatric surgery.
BACKGROUND
It has been shown that vagal nerve stimulation (VNS) can affect body mass. The aim of this study was to evaluate effect of VNS on body mass, body composition, metabolic rate, and plasma leptin and IGF-I levels.


METHODS
Eight female pigs were included in the study. Under general anesthesia, a bipolar electrode was implanted on the anterior vagal nerve by laparoscopy. Group A was treated by VNS, and group B was the control. After 4 weeks, stimulation was discontinued in group A and started in group B. The following parameters were evaluated: body mass, body composition, metabolic rate, plasma leptin and IGF-1 levels and intramuscular fat content (IMF).


RESULTS
VNS attenuated body weight gain (2.28 +/- 3.47 kg vs 14.04 +/- 6.75 kg; P = .0112, for stimulation and nonstimulation periods, respectively), backfat gain (0.04 +/- 0.26 mm vs 2.31 +/- 1.12 mm) and IMF gain (-3.76 +/- 6.06 mg/g MS vs 7.24 +/- 12.90 mg/g MS; P = .0281). VNS resulted in lower backfat depth/loin muscle area ratio (0.33 +/- 0.017 vs 0.38 +/- 0.35; P = .0476). Lower plasma IGF-I concentration was found after VNS (-3.67 +/- -11.55 ng/mL vs 9.86 +/- 10.74 ng/mL; P = .0312). No significant changes in other parameters were observed.


CONCLUSIONS
VNS affects body weight mainly at the expense of body fat resources; however, metabolic rate is not affected.
Sobocki
Jacek
J
Department of Digestive Surgery, CHU Rangueil, University Paul Sabatier, Toulouse, France. jsobocki@cm-uj.krakow.pl
Fourtanier
Gilles
G
Estany
Joan
J
Otal
Phillipe
P
D000818:Animals; D050110:Bariatric Surgery / Q000379:methods*; D001823:Body Composition; D015992:Body Mass Index; D001835:Body Weight; D004599:Electric Stimulation Therapy; D005260:Female; D007334:Insulin-Like Growth Factor I / Q000032:analysis; D020738:Leptin / Q000097:blood; D009765:Obesity / Q000628:therapy*; D013552:Swine; D014630:Vagus Nerve / Q000502:physiology*
D020738:Leptin; D007334:Insulin-Like Growth Factor I