The TANTALUS system for obesity: effect on gastric emptying of solids and ghrelin plasma levels.

BACKGROUND

Gastric electrical stimulation (GES), using the implantable TANTALUS System, is being explored as a treatment for obesity. The system delivers nonstimulatory electrical signals synchronized with gastric slow waves, resulting in stronger contractions. We hypothesized that this GES may enhance gastric emptying and as a result affect plasma ghrelin and insulin homeostasis. The aim was to test the effect of GES on gastric emptying of solids and on ghrelin and insulin blood levels in obese subjects.

METHODS

The system consists of 3 pairs of gastric electrodes connected to an implantable pulse generator. Gastric emptying test (GE) of solids was performed twice, on separate days, a few weeks after implantation, before and after initiation of stimulation. Blood samples for ghrelin and insulin were taken at baseline and at 15, 30, 60 and 120 min after the test meal.

RESULTS

There were 11 females, 1 male, mean age 39.1 +/- 8.9 years, mean BMI 41.6 +/- 3.4. Data is available from 11 subjects; GE was normal in 9 subjects and accelerated in 2 subjects. GES significantly accelerated GE compared to control: percent retention at 2 hours 18.7 +/- 12.2 vs 31.9 +/- 16.4, respectively (P < 0.01). Overall, there was no significant change in ghrelin or insulin profile after food intake. Ghrelin levels fell significantly at 60 min compared to baseline during stimulation (P = 0.014) and control (P = 0.046).

CONCLUSION

GES results in a significant acceleration of gastric emptying of solids in obese subjects. GES did not have a significant effect on postprandial ghrelin levels when compared to control.