Hypoglycemia in type 2 diabetes

Iatrogenic hypoglycemia is the limiting factor in the glycemic management of diabetes and a barrier to true glycemic control and its established microvascular and potential macrovascular long-term benefits. Compared with T1DM, severe hypoglycemia occurs less frequently in T2DM, even during aggressive glycemic therapy, presumably because of intact glucose counter-regulatory systems early in the course of T2DM. Iatrogenic hypoglycemia, however, becomes a progressively more frequent problem, ultimately approximating that in T1DM, in advanced T2DM because of compromised physiologic and behavioral defenses against falling plasma glucose concentrations. These syndromes of defective glucose counter-regulation and hypoglycemia unawareness and the concept of hypoglycemia-associated autonomic failure are analogous to those that develop early in the course of T1DM. Caregivers should strive to reduce mean glycemia as much as can be accomplished safely by practicing hypoglycemia risk reduction: addressing the issue, applying the principles of aggressive glycemic therapy, and considering both the conventional risk factors and those indicative of compromised glucose counter-regulation. Clearly, people with diabetes need more physiologic approaches to glycemic control, using current regimens and those to be developed. Regimens need to be tailored to the degree of insulin deficiency: absolute in established T1DM, relative early in the course of T2DM, and progressively more absolute in advanced T2DM. The reality or possibility of hypoglycemia should not be used by the caregiver or the patient as an excuse for poor glycemic control particularly in view of the growing array of glucose-lowering drugs that can be used to optimize therapy and achieve the best control possible in a given individual with T2DM. Nonetheless, better methods such as those that provide plasma glucose-regulated insulin secretion or replacement are needed for people with T2DM, as well as those with T1DM, if we are to achieve euglycemia safely over a lifetime of diabetes.