Semilente-insulin at bedtime is superior to NPH-insulin for the suppression of the dawn-phenomenon in adolescents with type-I-diabetes.

The dawn-phenomenon causes high fasting glucose values in IDDM patients during puberty. Even a bedtime injection of intermediate-acting insulin does not reliably suppress glucose rises during the morning hours. We therefore examined whether Semilente, an amorphous zinc insulin with kinetics different from NPH insulin, is better suited to alleviate the dawn-phenomenon in adolescent patients with long-standing diabetes. This prospective study included 15 adolescent patients (age 15.5 +/- 0.4 years; mean +/- SE) well beyond the remission phase of diabetes (mean duration: 7.5 +/- 0.8 years). On an inpatient basis, blood glucose profiles following bedtime injections of NPH or semilente insulin were compared, using a sequential cross-over design for intra-patient comparison. Fasting blood glucose was significantly lower following bedtime injections of Semilente (183 +/- 21 mg/dL [10.2 +/- 1.1 mmol/L]) compared to nights where NPH had been injected (235 +/- 22 mg/dL [13.1 +/- 1.2 mmol/L]). In addition, the morning postprandial blood glucose was significantly improved. The frequency of nocturnal hypoglycemia was not different, and the dose of Semilente insulin was slightly lower compared to the dose of NPH-insulin injected. For adolescent IDDM patients with suboptimal metabolic control due to a marked dawn-phenomenon, with high fasting glucose concentrations despite a bedtime injection of NPH insulin, bedtime injection of Semilente insulin may result in reduced fasting hyperglycemia on the next morning.