Substitution of basal delivery of insulin by proinsulin in type I diabetic patients under CSII.Horm Metab Res Suppl 1988; 18:74-7HM
In seven C-peptide negative type I diabetic patients conventional insulin therapy was replaced by CSII using biosynthetic human insulin. After a pretest period of 1-3 days duration, the patients received in randomized order basal subcutaneous infusion of either biosynthetic human proinsulin (assumed potency 4 U/mg) or insulin for two days each. For meals, insulin was given throughout the study. Insulin doses were adjusted to the patients requirements during the prephase. Afterwards changes of basal rates were allowed only in case of nocturnal hypoglycemia; bolus doses were modified when premeal glucose concentrations were outside the range from 80 to 120 mg/dl. During the test period with basal proinsulin infusion, plasma glucose control (MBG, MAGE, M-value) was significantly better (P less than 0.05) when compared to periods with basal insulin infusion. Basal rates of insulin and proinsulin as well as bolus doses of insulin were similar at all study periods. It is concluded that subcutaneous basal proinsulin infusion, supplemented by subcutaneous premeal insulin administration, can be used for glucose control of patients with type I diabetes. As basal proinsulin delivery gives significantly better results than basal insulin delivery, the question arises whether the present formulation of proinsulin is equipotent to insulin formulations.