Severe hypoglycaemia in children and adolescents during multiple-dose insulin therapy

Episodes of severe hypoglycaemia, resulting in coma and/or convulsions, were documented in an unselected, population-based group of 376 children and adolescents with Type 1 diabetes mellitus (Type 1 DM) treated at the Aurora Hospital, City of Helsinki. A prospective study in 1994-95 yielded 493 patient-years and a retrospective study in 1990-93, 904 patient-years of data. Of these patients, 77-85% received insulin in three or more daily doses. During 1990-95, 43 patients had a total of 48 severe hypoglycaemic episodes. For each episode (n = 48), one control Type 1 DM patient who had never experienced any severe hypoglycaemia, matched by age, diabetes duration and puberty, was sought from the study population. Incidence of severe hypoglycaemia was 3.1/100 patients years prospectively and 3.6/100 retrospectively. At the time of the episode, median age was 13.3 (range 2.2-21) years, and median diabetes duration 6.1 (0.5-14.6) years. Rates were similar in different age groups (< 6, 6-12.9 and > or = 13 years). A potential explanation for the hypoglycaemia was found in 79% of the episodes. Insulin dose was higher (p = 0.04) and HbA1c lower (p = 0.005) in patients with severe hypoglycaemia than in controls. In conclusion, multiple-dose insulin therapy in young patients with Type 1 DM can be associated with a low rate of severe hypoglycaemia. The majority of such episodes seem to be preventable.