Glucose disposal and intermediary metabolism during one year of continuous subcutaneous insulin infusion (CSII)

To study the effects of CSII on insulin action and intermediary metabolism, seven type 1 diabetic patients (duration 17 +/- 4 (SEM) years), underwent sequential euglycemic clamps 1/4, 6 and 12 months after changing from conventional insulin treatment to continuous subcutaneous insulin infusion (CSII); seven healthy subjects served as controls. For at least 14 h before the study, blood glucose was maintained between 4-10 mmol/l in the patients by intravenous insulin infusion, to avoid negatively biased clamp measures. A metabolite profile was taken in the basal state and during euglycemic hyperinsulinemia. At 1/4 month insulin sensitivity was decreased in the patients (ED50 82 +/- 14 vs 52 +/- 4 mU/l in controls, P less than 0.02), whereas insulin responsiveness was normal. During the course of one year, no change towards control values was found for insulin-stimulated glucose disposal. Concomitantly, HbA1 did not change either, and remained elevated (1/4 month 11.1 +/- 0.7%, 12 months 10.0 +/- 0.9% vs 6.5 +/- 0.3% in controls, P less than 0.01). Regarding basal intermediary metabolism, triglycerides became significantly improved (1/4 month 1.32 +/- 0.13 mmol/l, 12 months 0.70 +/- 0.05 mmol/l, P less than 0.05, vs 0.70 +/- 0.08 mmol/l in controls). The acetoacetate/3-OH-butyric acid ratio increased from 0.10 at 3 to 0.26 at 12 months, which was similar to controls. The absolute levels of acetoacetate and 3-OH-butyric acid remained elevated 2-3 fold. For other basal metabolite levels no systematic trend for improvement was found for 1/4 to 12 months.(ABSTRACT TRUNCATED AT 250 WORDS)