Grant: Operating Grant

Recent studies using positron emission tomography (PET), a diagnostic tool that allows quantification of tissue glucose uptake, have demonstrated the presence of brown adipose tissue (BAT) in humans. Metabolism of this tissue is activated by cold exposure and appears to be less active in obese and diabetic individuals. We demonstrated the contribution of BAT to energy expenditure and glucose and fatty acid utilization in healthy humans and found that it is less activated in subjects with diabetes. Using sophisticated PET and tracer techniques that allows quantification of tissue energy utilization and glucose and dietary fatty acid uptake, we will determine how much energy and fat BAT dissipates after a meal prior to and after increasing BAT activity using a validated 4-week cold acclimation protocol in otherwise healthy men with and without pre-diabetes (glucose intolerance). Energy expenditure, shivering, hormonal and metabolic responses to cold will be simultaneously determined. The proposed study will determine the true potential of activating BAT to dissipate energy and dietary fat after meal intake as a strategy to prevent and treat obesity and type 2 diabetes.