Failure of current insulin regimes to meet the overnight requirements of adolescents with insulin-dependent diabetes.

The study was undertaken to determine whether overnight insulin requirements were being met during conventional insulin therapy in adolescents with IDDM. Overnight glucose and insulin profiles were compared when the subjects were on their usual insulin regime (baseline) and when the blood glucose was clamped using a variable rate insulin infusion (clamp). Thirteen adolescents (5 boys and 8 girls, median age 12.2 yr; range 10.5-15.4 yr; Median HBA1 11.4%; range 8.4-15.6) took part in the study. Three were on twice daily, two on multiple injection therapy and two on once daily insulin therapy. During the baseline studies, blood glucose concentrations fell to a nadir at 0200-0400 hr and then rose during the early hours of the morning. The clamp studies confirmed that the insulin requirement for euglycaemia was higher between 0500 and 0800 hr (15.4 +/- 0.9 mU/kg/hr) than between 0100 and 0400 (12.1 +/- 1.1 mU/kg/hr; p = 0.002). Comparison of the free insulin concentrations between the baseline and clamp nights, indicated that during the baseline study subjects were relatively over-insulinized during the early part of the night and under-insulinized during the latter part of the night irrespective of what insulin regime they were receiving. We conclude that current insulin regimes do not provide appropriate insulin delivery for the control of blood glucose during puberty.