Normalization of plasma insulin profiles with intraperitoneal insulin infusion in diabetic man

This study examined the feasibility of normalizing the plasma insulin profile in five insulin deficient diabetic males. Acute meal-related increases in plasma free insulin concentration were achieved by administering short-acting insulin intraperitoneally with a pre-programmed portable rotary splenoid driven pump. This insulin response was compared to that achieved when short-acting insulin was injected subcutaneously 15 minutes prior to each meal. After intraperitoneal insulin maximal plasma free insulin concentration was observed within 45 minutes of administration, and averaged 40 +/- 13 mU/l(+/- SEM) for breakfast, 30 +/- 13 mU/l for lunch, and 36 +/- 13 mU/l for supper. This acute rise was followed by a gradual decline in plasma free insulin concentration, simulating a normal plasma insulin profile. With subcutaneously injected insulin, approximately the same maximal plasma free insulin concentration was obtained as observed with intraperitoneal insulin, but it was delayed 116 minutes following injection. These data suggest that intraperitoneally delivered insulin is rapidly absorbed and may normalize the peripheral plasma free insulin concentration, at least during short-term studies.