Severe hypoglycaemia in drug-treated diabetic patients needs attention: A population-based study

Objective. To study one-year incidence and risk factors of severe hypoglycaemias (SH) in adult drug-treated diabetic patients living in two Finnish communities. Design. The episodes of SH and their risk factors were identified from local ambulance registers, from the databases of local health care units, and from patient questionnaires. Setting. The target population consisted of all drug-treated diabetic patients from the two middle-sized communities in southern Finland, altogether 1776 patients. The study was retrospective. Subjects. A total of 1469 patients (82.7% of the target population) gave informed consent for the use of their medical records and 1325 patients (74.6% of the target population) returned the detailed 36-item questionnaire. Results. Of type 1 and type 2 insulin-treated diabetic patients, 14.6% and 1.0%, respectively, needed ambulance or emergency room care (incidence of 30.5 and 3.0 per 100 patient years). However, 31.0% of type 1 and 12.3% of type 2 diabetic patients reported at least one episode of SH (incidence of 72.0 and 27.0 per 100 patient years). Of all insulin-treated patients, 53 (7.8%) reported three or more episodes of SH. Significant independent risk factors for SH were depression, daily exercise, and nephropathy but not glycaemic control. Conclusion. The incidence of SH was high in both types of insulin-treated diabetic patients. However, the recurrent episodes of SH were clustered in a small minority of insulin-treated patients with diabetes. The risk of SH should be considered when assessing the treatment target for an individual diabetic patient.