Is there anything positive about iatrogenic hypoglycemia in Type 1 diabetes

281 ISSN 1758-1907 10.2217/DMT.13.25 © 2013 Future Medicine Ltd Diabetes Manage. (2013) 3(4), 281–283 Iatrogenic hypoglycemia is the most frequent acute complication of insulin therapy. Although the true incidence is difficult to ascertain, it is estimated that patients with Type 1 diabetes experience two to three hypoglycemic events per week and one severe event, requiring third-party assistance, once every 1–2 years [1]. There is substantial interand intra-individual variation in the incidence of hypoglycemic events, ranging from almost none to one or even multiple events per day. Hypo glycemia is considered to be the principal limiting factor to achieve optimal glycemic control in Type 1 diabetes because it is usually unavoidable in the pursuit of near-normal glucose levels [1]. Other factors impacting on the rate of hypoglycemia include (residual) b-cell function, the potency of glucose counter-regulatory function and hypo glycemic awareness. In addition, time of day (daytime versus nighttime), ambient temperature and other environmental factors (e.g., exercise or alcohol use) may play a role in the day-to-day variation. Approximately 25–30% of patients with Type 1 diabetes have severely impaired hypoglycemic awareness, meaning that hypoglycemia does not or only minimally elicits classical warning symptoms, such as sweating, pounding heart or trembling. In these patients, counter-regulatory hormone responses to hypoglycemia are often similarly impaired, meaning that glucose levels may fall more or less unimpeded. Since antecedent hypoglycemia exerts an attenuating effect on the counter-regulatory and symptom responses to subsequent hypoglycemia [2], impairments in both counter-regulatory function and hypoglycemic awareness are thought to result from habituation to recurrent hypoglycemia. The clinical syndrome of severely impaired hypoglycemic awareness thus results from a vicious cycle of recurrent hypoglycemia and progressive counter-regulatory impairments. Patients with this syndrome are at a sixto ten-fold higher risk of severe hypoglycemia compared with those reporting normal hypoglycemic awareness [3]. Severe hypoglycemic events are feared by many patients, relatives and care providers, mainly because of the associated loss of selfcontrol and its potential to cause direct or indirect harm. Extremely low blood glucose levels lasting for several hours may permanently damage the brain and occasionally be fatal. Although such events are extremely rare, a large survey of cause-specific mortality in the UK nevertheless attributed 4% of