Objective — To evaluate whether an insulin regimen with a long-acting zinc insulin (Ultratard HM) could help control fasting hyperglycemia in insulin-dependent diabetes mellitus (IDDM) patients.

Research Design And Methods — A randomized sequential crossover trial with 6-wk treatment periods was used. Ten IDDM patients from the diabetes clinic at the Medical School who had persistent fasting hyperglycemia (> 10 mmol/L) were studied. Patients with nocturnal hypoglycemia were excluded. All patients completed the study. Insulin regimens consisted of three daily injections of a short-acting insulin (Actrapid HM) before meals and either a long-acting zinc insulin (Ultratard HM) or an intermediate isophane insulin (Protaphane HM) before the evening meal. Each regimen was followed for 6 wk.

Results — Fasting blood glucose levels (at 06:00 and 08:00) were significantly lower after the long-acting insulin regimen (6.26 ± 0.88 vs. 10.82 ± 4.27 mM, P < 0.05 and 9.26 ± 1.02 vs. 14.03 ± 1.08 mM, < 0.05, respectively). Plasma-free insulin levels mirrored blood glucose concentrations because they were significantly higher at 06:00 and 08:00 after the long-acting insulin regimen (49.5 ± 10.1 vs. 20.1 ± 4.3 pM, P < 0.05 and 31.6 ± 5.0 vs. 16.5 ± 3.4 pM, P < 0.05, respectively). At any other time of the day, blood glucose and plasma insulin levels were not significantly different with either one of the two insulin regimens.

Conclusions — A long-acting zinc human insulin injected before the evening meal can help to control persistent fasting hyperglycemia in IDDM patients.