Measurement of Glucose Metabolism in Humans: Effect of Recurrent Hypoglycemia on Hypothalamic GABA

Glucose is a major fuel for most organs in the human body, particularly the brain. How and where the body uses glucose is regulated by a number of hormones, for instance insulin and glucagon. In a number of diseases, in particular diabetes mellitus, the glucose supply to the brain may be different than normal, which may be a cause for reduced glucose awareness. The purpose of this study is to determine the effects of altered glucose metabolism on the brain. For example, patients with long duration diabetes mellitus lose their ability to secrete the hormones necessary to protect them against hypoglycemia, which may be due to alterations in glucose availability to the human brain. To measure these effects, we will use intravenous infusions of glucose and insulin.