Trial of the Combination of Alpha-Lipoic Acid and Mirabegron in Women and in Men With Obesity

Background: Obesity and related illnesses cause at least 2.8 million deaths each year worldwide. Few treatments exist for obesity that are safe and widely available. A study drug (mirabegron \[MG\]) combined with a supplement (alpha-lipoic acid \[ALA\]) may help. Objective: To learn how MG and ALA can help the body process food. Eligibility: People aged 18 to 65 years with a body mass index between 30 and 45 kg/m2. Design: Participants will be screened. They will have a physical exam. They will have blood and urine tests and a test of their heart function. They will speak with a dietician. The study has two phases. Each phase begins with a 2-day stay in the clinic; then the participant will take the study drugs at home for about 4 weeks, followed by another 2-day stay in the clinic. They will also have outpatient visits about 2 weeks after each clinic stay. During the clinic stays, participants will undergo many tests: They will have a plastic tube (catheter) inserted into a vein in each arm. These will be used to draw blood and to infuse glucose (sugar) and insulin. They will have imaging scans. They will have a clear hard plastic shield placed over their head to measure oxygen and carbon dioxide as they breathe. Participants will take the study drugs at home. Both MG and ALA are taken by mouth with water. During one phase, participants will take MG plus a placebo. A placebo looks like the study drug but doesn t contain medicine....