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.