ISLET-CELL FUNCTION IN TYPE-1 AND TYPE-2 DIABETES

The primary hormone controlling glucose metabolism is insulin. A defic iency in insulin secretion is a central defect in the pathophysiology of both type 1 and type 2 diabetes. In this review we discuss the abno rmalities of insulin secretion characteristic of both forms of diabete s. We describe most of the commonly employed tests of beta cell functi on and explore their relative advantages and disadvantages. Usually, t here is a trade-off between the complexity of the test and the amount of information obtained. For example, measuring insulin or C-peptide d uring the fasting state provides far less information on total beta ce ll functional capacity than does dynamic beta cell testing at differen t glucose levels using several intravenous beta cell secretagogues. Si nce insulin and C-peptide are the primary measurements used during bet a cell testing, a few caveats are provided regarding both of these ass ays and the interpretation of results.