Prospective, Randomised Study: Metabolic and Functional Effects of Bariatric Surgery Accessed Using PET and MRI

The objectives of this study are to measure effect of obesity on brain structure and molecular pathways, food-stimuli mediated brain activation response, on hormones affecting both feeding and energy balance as well as on bone metabolism and bone marrow fat. In the first phase the studies are performed at baseline before bariatric surgery and in the second phase post-operatively after 6 months. Regional free fatty acid uptake are studied with PET and 14(R, S)-[18F]-fluoro-6-thia-heptadecanoic acid ([18F]FTHA). Changes in body fat distribution are investigated with magnetic resonance imaging (MRI) Brain reward system response to food stimuli is assessed using functional MRI (fMRI) and white and grey matter volumes using diffusion tensor imaging (DTI). Brain neurotransmitter system will be measured with [11C]raclopride and [11C]carfentanil and PET. In the second part of the study the same variables are studied after bariatric surgery: either laparoscopic sleeve gastrectomy or Roux-en-Y gastric bypass.