The impact of the Diabetes Control and Complications Trial and Humalog insulin or glycohemoglobin levels and severe hypoglycemia in type 1 diabetes

QBJECTIVE - This study was performed to determine the effects of the Diabet es Control and Complications Trial (DCCT) report in 1993 and the introducti on of Lispro (Humalog) insulin in 1996 on glycemic control and on the numbe r of severe hypoglycemic episodes in type 1 diabetic patients of various ag es. RESEARCH DESIGN AND METHODS - Diabetes care parameters and HbA(1c) data fro m 884 subjects with type 1 diabetes were entered into our database at the t ime of clinic visits from 1993 through 1998. In addition, a questionnaire w as sent to all patients to validate the number of insulin injections per da y, the incidence of severe hypoglycemic episodes las defined by the (DCCT), and the use of Humalog insulin. Data were divided into four age-groups: (5 , 5-12, 13-18, and >18 years of age. RESULTS - Longitudinal HbA(1c) levels declined significantly after the DCCT report in 1993-1996 (P < 0.001), but the number of severe hypoglycemic eve nts increased (P < 0.001). A second decline in HbA(1c) levels was observed after the introduction of Humalog insulin in 1996 (P < 0.001). However, sev ere hypoglycemic episodes did not change (P = 0.26). CONCLUSIONS - Administration of Humalog resulted in an additional reduction in HbA(1c) levels beyond the reduction in HbA(1c) values after the DCCT re port. In contrast to the increase in severe hypoglycemic events after the D CCT results, the number of severe hypoglycemic episodes did nor increase af ter the introduction of Humalog, despite a further decrease in HbA(1c) valu es.