Feature Article

Recurrent hypoglycemia and the development of permanent brain damage in diabetic adults

Christopher M. Ryan, PhD

Diabetic Hypoglycemia January 2009, Volume 1, Issue 3: page 3-7

Abstract

Falling blood glucose generates autonomic and neuroglycopenic symptoms which can lead to discomfort and mild cognitive dysfunction. The risk of neurological damage increases as the degree of hypoglycemia worsens, and severe hypoglycemia may potentially induce significant and lasting central nervous system (CNS) damage.

This article studies the effects of both moderate and severe hypoglycemia on the CNS, investigating whether hypoglycemic events cause lasting damage, and discussing the widely held belief that hypoglycemia may cause cognitive impairment. A number of different studies are reviewed, including the Diabetes Control and Complications Trial (DCCT) and its continuation study, the Epidemiology of Diabetes Interventions and Complications Study (EDIC). The article also studies the use of neuroimaging and electrophysiology to determine the effect of hypoglycemia on neural activity, and considers the question of whether recurrent moderate or severe hypoglycemia is ever truly benign.

The article concludes that, at least in young and middle-aged adults, one or more episodes of moderate or even severe hypoglycemia frequently do not induce cognitive dysfunction, and are unlikely to result in lasting long-term adverse effects on the CNS of adults with diabetes. Permanent damage is more likely to occur when hypoglycemia is profound and persistent.

Keywords: hypoglycemia, CNS damage, cognitive dysfunction