Article of the Week: Be Aware of Hypoglycemia Unawareness

The assertion that hypoglycemia unawareness is both preventable and treatable is unsubstantiated by the facts. While it is usually preventable in most patients, Diabetes Self-Management is implying that hypoglycemia unawareness is due to patient error exclusively. Unfortunately, the reality is that its not that simple.

More correctly, hypoglycemia is the result of the interplay of absolute or relative insulin excess and compromised glucose counterregulation in established (C-peptide-negative) T1DM. As plasma glucose levels decline, insulin levels do not decrease-they are simply a passive reflection of the absorption of exogenous insulin, and glucagon levels do not increase. The mechanism of the latter defect is poorly understood, but it is tightly linked to, and possibly the result of, insulin deficiency. Thus, the first and second defenses against hypoglycemia are lost in established T1DM, leaving patients with only one element of counterregulatory function.

Further, the epinephrine response is typically attenuated, i.e., the glycemic threshold for the epinephrine response is shifted to lower plasma glucose concentrations. This reduction of the third defense is largely the result of recent antecedent iatrogenic hypoglycemia, thus this one element may be prevented, but clinicians have no ability to address the other counterregulatory impairments.