Hypoglycemia in type 1 diabetes mellitus

Abstract

Iatrogenic hypoglycemia, typically the result of the interplay of therapeutic hyperinsulinemia and compromised defenses resulting in hypoglycemia-associated autonomic failure (HAAF) in diabetes, is a problem for people with type 1 diabetes mellitus (T1DM). It causes recurrent morbidity is sometimes fatal, leads to recurrent hypoglycemia, and precludes euglycemia over a lifetime of T1DM. Risk factors include those that result in relative or absolute insulin excess and those indicative of HAAF in diabetes. Elimination of hypoglycemia from the lives of people with T1DM will likely be accomplished by new treatment methods that provide plasma glucose-regulated insulin replacement or secretion.

Figure 1

Physiological and behavioral defenses against hypoglycemia in humans and their compromise in people with T1DM. ACh, acetylcholine; NE, norepinephrine; PNS, parasympathetic nervous system; SNS, sympathetic nervous system. From Cryer PE. Mechanisms of sympathoadrenal failure and hypoglycemia in diabetes. J Clin Invest 2006;116(6):1471, with permission of the American Society for Clinical Investigation.

Figure 2

Schematic diagram of defective glucose counterregulation and hypoglycemia unawareness, and the unifying concept of hypoglycemia-associated autonomic failure, in T1DM. From Cryer PE. Exercise-related hypoglycemia-associated autonomic failure. Diabetes 2009;58(9):1952, with permission of the American Diabetes Association.