How Gas-Filled Intragastric Balloons or Endoscopic Sleeve Gastroplasty Affect Hunger, Hunger Hormones, and Gastric Emptying Compared to Meal Replacements

The disease obesity continues to be a major health issue in the US with over one third of the population having a mass index \>30 kg/m2. Obesity is associated with serious cardiometabolic complications including diabetes, hypertension, dyslipidemia and myocardial infarction. Rates of successful obesity treatment with weight loss and weight maintenance remain low. Several endoscopic bariatric therapies and procedures have been approved for use in the United States, including three intragastric balloon systems (2 fluid-filled and one gas-filled) and endoscopic sleeve gastroplasty (ESG), both of which have lower risks than bariatric surgery and do not alter gastrointestinal anatomy. Weight loss with all intragastric balloons and ESG is higher than lifestyle therapy or weight loss medications, but less than bariatric surgery. Unlike weight loss medications where weight loss from the medication is regained within 6-8 months after therapy ends, weight loss maintenance with intragastric balloons remains high with 66-88.5% of the weight loss maintained 6 months after device removal. Data suggests that space occupying devices with a volume of 400 ml or more in the stomach increase feelings of fullness and result in weight loss, but this does not explain the prolonged effect of weight loss maintenance after balloon removal. Although few studies have investigated the mechanism of action of fluid-filled balloons and one study with 4 patients undergoing ESG on weight loss, these data suggest that gastric emptying as well as space occupation contribute to weight loss. However, no studies have investigated the mechanisms of action of gas filled intragastric balloons on weight loss. Understanding the mechanisms responsible for weight loss with the gas filled intragastric balloon system and ESG as well as any weight loss independent effects on blood glucose control would lay the groundwork for studies evaluating predictors of response to improve patient selection as well as studies understanding the mechanisms behind weight loss maintenance and developing strategies to prolong weight loss maintenance. Therefore, the purpose of this pilot study is to determine the effects 10% total body weight loss (%TBWL) in patients with obesity treated with the intragastric balloon (GF- IGB) system or ESG compared to patients with obesity treated with a meal replacement program (MRP) on 1) gastric emptying, 2) hormonal adaptation to weight loss and 3) hunger.