Risk of Hypoglycemia in Type 2 Diabetes

Hypoglycemia is a condition characterized by abnormally low blood glucose (blood sugar) levels, usually less than 70 mg/dL. This condition is recognized to be one of the main restrictions in achieving normal control in type 1 diabetes. Historically, the risk of hypoglycemia has been considered lower in type 2 diabetes, however, with the increasing use of insulin to treat type 2 diabetes, the occurrence of hypoglycemia has the potential to intensify.

The focus on the relationship between hypoglycemia and type 1 diabetes is due to the frequency of hypoglycemia in these patients. Per the American Diabetes Association, on average, people with type 1 diabetes experience hypoglycemia around twice a week. This number equates to a prevalence of 30% to 40% a year.

It is more difficult to originate equivalent figures for patients with type 2 diabetes because of the diversity. Statistically, the majority of people with type 2 diabetes are middle aged or elderly, and accurate measures of the frequency of hypoglycemia in elderly people are most likely underestimated.¹ In addition to this, when people with type 2 diabetes become insulin deficient, they experience hypoglycemia as frequently as people with type 1 diabetes, and it may go unreported.

Studies behind hypoglycemia and type 1 diabetes show that severe hypoglycemia is reported robustly over a period of one year, and mild hypoglycemia is unreliable after only one week.²^,³ Likewise, studies supporting insulin-treated type 2 diabetes report severe hypoglycemia over a period of one year, but the difference is in the results of mild hypoglycemia. Some studies focused on hypoglycemia in type 2 diabetes have overlooked the effects of ageing by selecting middle-aged subjects. The scarcity of elderly people is concerning because this age-group is at the greatest risk of illness as a result of hypoglycemia, especially since their symptoms are often masked and they do not receive prompt treatment.

The frequency of hypoglycemia in type 2 diabetes may not be considered as common as hypoglycemia in type 1 diabetes, but misleading information may have caused this misperception. Hypoglycemia occurs most frequently with insulin therapy, which can occur in type 1 and type 2 diabetes. With the rise in the need of insulin therapy in both illnesses, the risk of hypoglycemia should not be underestimated.

References:

1. McAulay V, Frier BM. Hypoglycaemia: Diabetes in Old Age. 2nd ed. Sinclair AJ, Finucane P, Eds. Chichester, U.K., John Wiley and Sons, 2001, p133–152.
2. Pramming S, Thorsteinsson B, Bendtson I, Binder C. Symptomatic hypoglycaemia in 411 type 1 diabetic patients. Diabet Med 8:217–222,1991.
3. Pedersen-Bjergaard U, Pramming S, Thorsteinsson B. Recall of severe hypoglycemia and self-estimated state of awareness in type 1 diabetes. Diabetes Metab Res Rev 19:232–240,2003.