Conditions: Weight Loss Obesity
Keywords: Weight Loss Byetta (Exenatide) Energy Expenditure Food Intake Obesity
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 150
Healthy volunteers: yes

Brief summary:
Exenatide is an incretin-like drug that has been approved for treatment of type 2 diabetes; it improves glycemia by increasing insulin and decreasing glucagon secretion by pancreatic islet cells and delaying gastric emptying. This randomized, placebo-controlled study is to evaluate whether exenatide over a 5 week period in non-diabetic obese subjects may lead to weight loss. To control for variability in individual response to weight loss treatment, this study will assess the role of exenatide in changing food intake and energy expenditure as possible sources of weight loss. This study will also evaluate the safety profile of exenatide in non-diabetic obese people. Additional assessments will evaluate changes in body fat and hormones involved in the sensations of hunger and fullness.

Detailed description:
Obesity can lead to a number of health problems including diabetes, heart disease, stroke, low back pain, fatty liver disease, and osteoarthritis. The medical treatments currently available for obesity are limited. Exenatide is an injectable medication approved for treatment of type 2 diabetes that causes weight loss in some diabetic subjects. The reasons exenatide is thought to cause weight loss include decreased food intake, increased feelings of fullness and nausea. Because levels of a human gut hormone (glucagon like peptide 1) that is similar to exenatide have been shown to be related to resting energy expenditure, it is also possible that exenatide may have effects on a person s metabolism, a.k.a. energy expenditure, but any effect of exenatide on energy expenditure has yet to be evaluated. Even though exenatide is used to treat diabetes, administration of exenatide to non-diabetic lean individuals did not cause frankly low blood sugars.

The primary goal of this study is to investigate the way in which exenatide given twice a day to obese (BMI \>= 30 kg/m\^2) people without diabetes might lead to weight loss. Because response to weight loss treatment can be highly variable between individuals, we will look at the role of exenatide in changing food intake and energy expenditure as possible explanations for weight loss. We will also assess the safety profile of exenatide in non-diabetic obese people.

This study will involve the use of exenatide or placebo, determined randomly, in obese individuals without diabetes over a 5 week period. The primary measurements will include effects of exenatide on energy expenditure and food intake. We will also look at changes in body fat and the levels of hormones involved in the sensations of hunger and fullness. We will assess if any exenatide-induced changes can predict which individuals lose weight over the 5 weeks. The safety and side effects of exenatide in non-diabetic individuals during this time will also be determined. Findings from this study would help to determine how exenatide works to cause weight loss in people without diabetes, who might benefit most, and would help to improve understanding of why some people respond better to weight loss treatment than others.

Arms:
arm 1: 10 micrograms subcutaneously twice arm 2: Twice daily

Interventions: intervention 1: Byetta (exenatide) intervention 2: Weight loss intervention 3: Metabolic Chamber intervention 4: Placebo
Intervention descriptions: intervention 1: Exenatide is an injectable medication intervention 2: Because response to weight loss intervention 3: The subject stays in the small room intervention 4: None

Protocol document: