Variables associated with severe hypoglycemia in children and adolescents with type 1 diabetes: a population-based study

Objective: Hypoglycemia remains a central problem in the management of type 1 diabetes mellitus (T1DM) and limits the achievement of good or normal glycemic control. The Diabetes Control and Complication Trial showed that intensive treatment of T1DM increased the risk of severe hypoglycemia (SH) when compared to conventional therapy. The aim of our study was to determine the incidence of SH and associated variables in a population of children and adolescents with T1DM. Research design and methods: We performed a 7.5-yr prospective study enrolling 195 patients aged 13.9 +/- 6.6 yr. The study was carried out by referring to the T1DM population-based register in the Abruzzo region of Italy. The incidence of SH, defined as blood glucose levels < 50 mg/dL (< 2.77 mmol/L) associated with altered states of consciousness (including confusional state, seizures, and coma) was recorded. Glycated hemoglobin (HbA1c) percentage, insulin dose, insulin regimen, time since diagnosis, and age at onset were also recorded. Results: One hundred and thirty-three severe hypoglycemic events occurred during the study period; the overall incidence was 9.4 episodes per 100 patient-years. Significant predictors of hypoglycemia were diabetes duration > 10 yr (p = 0.01), basal/bolus insulin ratio (ratio of daily basal insulin units to daily bolus insulin units) > 0.8 (p = 0.01). No relationship was found between hypoglycemic episodes and HbA1c levels, daily insulin requirements, or insulin regimen. Conclusions: In these patients, a relatively low incidence of SH was recorded, without pronounced association with lower HbA1c or multiple daily injection insulin therapy. SH seems to be mainly related to management of diabetes. We believe that the main path to SH prevention is through patient and family education in the management of T1DM.