HIV protease inhibitors (PIs) have been associated with type 2 diabetes. To design future HIV drugs that have have the least adverse metabolic effects, it is necessary to identify the disorders of glucose metabolism with PI therapy. Previously PIs have been shown to acutely induce insulin resistance in the periphery. Preliminary data show that PIs also impair insulin secretion and increase hepatic glucose production in humans. These lesions are key contributors to the development of type 2 diabetes. Due to the difficulty in separating out factors related to HIV infection from the direct effect of PIs, an effective design is to study HIV-negative subjects to define the direct effects of PIs on the liver and pancreas on glucose metabolism: