Incidence and Costs of Severe Hypoglycemia

Hypoglycemia is a significant cause of morbidity and mortality and is the limiting factor in the successful metabolic control of diabetes. Severe hypoglycemic episodes can be life-threatening and are particularly feared by diabetic patients and their relatives.

In a prospective population-based study with sensitive screening for hypoglycemia, we determined the incidence and direct medical costs of severe hypoglycemia (SH) in a nonselected German population with 200,000 inhabitants (Detmold, East Westphalia) between 1997 and 2000. SH was defined as a symptomatic event requiring intravenous glucose or glucagon injection and was confirmed by a blood glucose measurement. To also detect atypical manifestations of SH, an initial blood glucose test from venous whole blood was performed in all 30,768 patients presenting to the medical emergency department of the region’s central hospital and in 6,631 (85%) of all 7,804 patients attended by the emergency medical service in the region. The diabetes prevalence in Germany on the basis of pooled epidemiological data is 5%. Of these, 90% have type 2 diabetes, while 6% have type 1 diabetes (1). Therefore, in the investigated region with a population of 200,000 there will have been ∼9,000 type 2 and 600 type 1 diabetic patients. During the 4-year period, 264 cases of SH (blood glucose 33 ± 17 mg/dl [SD]) were registered, comprising 14 (5%) cases of spontaneous hypoglycemia, 92 (35%) cases in type 1, 146 (56%) in type 2, and 10 (4%) in nonclassified insulin-treated diabetic patients. This corresponds to a rate of SH of 3.8/100 patients/year in type 1 diabetic patients and 0.4/100 patients/year in type 2 diabetic patients. These figures do not include the nonclassified insulin-treated diabetic patients. SH in type 1 diabetic patients was probably underreported because in some cases appropriately trained family members or carers would have been able to effectively treat SH by administration of glucagon without calling a doctor. Whereas 60% (55 of 92) of hypoglycemic patients with type 1 diabetes were treated only at the scene of the emergency by an emergency physician or in the hospital emergency department, hospitalization of patients with type 2 diabetes was usually unavoidable (95% [ 141 of 148]). Factors that contributed to inpatient treatment were poor general condition, concomitant disease requiring treatment, fractures and injuries sustained in connection with the hypoglycemia, and the need for monitoring in the 70 patients with sulfonylurea-induced hypoglycemia. Due to advanced age (76 ± 12 vs. 44 ± 17 years; P < 0.0001) and comorbidity (comedication 3.6 ± 2.6 vs. 1.0 ± 2.1 drugs; P < 0.0001), hypoglycemic individuals with type 2 diabetes spent considerably more time in hospital than type 1 diabetic patients (9.5 ± 10.6 vs. 2.3 ± 5.3 days; P < 0.0001). The total annual costs of SH including ambulance attendance ($391 per item), treatment by emergency physicians ($115 per item), hospitalization ($220 per day), and outpatient treatment ($22 per item) amounted to $44,338/100,000 inhabitants in type 2 diabetic patients and $8,129/100,000 inhabitants in type 1 diabetic patients.

SH is a common, cost-intensive complication of diabetes. Due to the high prevalence of type 2 diabetes there was a greater total number of events in type 2 than in type 1 diabetic patients. We believe that the medical and socioeconomic significance of SH in this specific group has been underestimated.