Intensified insulin therapy and the risk of severe hypoglycaemia

The objectives of the present analyses were to assess the association between HbA1 c levels and severe hypoglycaemia (SH, treatment with glucose i. v. or glucagon injection) and to identify predictors of SH in a prospective multicentre trial. The study population consisted of 636 insulin-dependent diabetic patients who had participated in a structured 5-day in-patient group treatment and teaching programme for intensification of insulin therapy (ITTP) in one of 10 hospitals and who were re-examined after 1, 2, 3, and 6 years including assessment of demographic, disease and treatment related parameters, diabetes-related knowledge, behaviour, and emotional coping. At baseline, age (mean ± SD) was 27 ± 7 years, diabetes duration 9 ± 7 years and HbA1 c 8.3 ± 1.9 %. During the 6-year follow-up, the mean HbA1 c value improved to 7.6 %, and in patients with a diabetes duration of more than 1 year at entry into the study (n = 538) the incidence of SH decreased from 0.28 cases/patient/year during the year preceding the ITTP to 0.17 cases/patient/year. The patient group was divided into decile groups according to mean follow-up HbA1 c values. In each group more than 230 patient years could be analysed. Groups with mean HbA1 c values of 5.7, 7.0, 7.4, 7.7 and 8.9 % had comparable risks of SH (0.15–0.19 cases/patient/year). In a logistic regression analysis, mean HbA1 c during follow-up, a history of SH during the year preceding the ITTP, C-peptide level, emotional coping, carrying emergency carbohydrates (as assessed at the 1-year follow-up), and age at onset of diabetes were significant independent predictors of SH. The incidence of SH between centres varied between 0.05 and 0.27 cases/patient/year. In conclusion, in the present analyses no linear or exponential relationship between HbA1 c and severe hypoglycaemia could be identified by using simple group comparisons. Applying complex regression analyses, various patient-related predictors of severe hypoglycaemia were identified. [Diabetologia (1997) 40: 926–932]