Prevalence of severe hypoglycemia in a cohort of patients with type 1 diabetes

Hypoglycemia is the major limiting factor in the glycemic management of type 1 diabetes. Severe hypoglycemia puts patients at risk of injury and death. Recurrent hypoglycemia leads to impaired awareness of hypoglycemia and this increases the risk of severe hypoglycemia. Recent studies have reported rates for severe hypoglycemia of 35% in type 1 diabetic patients. To assess the prevalence of severe hypoglycemia in type 1 diabetes mellitus patients and to evaluate the relationship between this and impaired awareness of hypoglycemia according to the Clarke test. The following data were collected from a cohort of type 1 diabetic patients: age, gender, duration of type 1 diabetes, treatment (multiple daily insulin injection or continuous subcutaneous insulin infusion), glycemia self-control, HbA1c, episodes of severe hypoglycemia and impaired awareness of hypoglycemia. Of the participants, 39.8% had had at least one episode of severe hypoglycemia (in the previous 6 months), 11.4% with loss of consciousness (in the previous 12 months). According to the Clark test, 40.9% had impaired awareness of hypoglycemia. Older age and longer duration of diabetes were associated with a higher prevalence of severe hypoglycemia with unconsciousness; older age and a lower level of HbA1c were associated with impaired awareness of hypoglycemia. Our study allows us to confirm the high rate of severe hypoglycemia and impaired awareness of hypoglycemia in patients with type 1 diabetes.