Determination of 24-hour insulin infusion pattern by an artificial endocrine pancreas for intravenous insulin infusion with a miniature pump.

Abstract

Intravenous insulin infusion with a glucose controlled insulin infusion system (GCIIS) is known to restore glucose homeostasis. A simpler approach to improve blood glucose regulation is preprogrammed intravenous insulin infusion with portable pumps without sensor-mediated feedback. We report a study designed to evaluate whether the preprogrammed insulin infusion pattern to be used in the miniature insulin infusion pump (MIIP) could be optimized by concomitant employment of the GCIIS for blood glucose control. Six juvenile-onset insulin-dependent diabetics (mean age 31 yrs) were studied. Mean blood glucose (MBG) was 6.2 mmol/l +/- 0.5 (SD) during glucose controlled infusion and 5.3 +/- 0.6 during the combined MIIP + GCIIS-day. The insulin requirements calculated from the s.c. regimen (56 U +/- 10 SD) were identical to the GCIIS-measured (51 U +/- 14) and to the amounts delivered during the combined MIIP-GCIIS infusion day (54 U +/- 13). A mean surplus of 3 U was given by the GCIIS. Mean amplitude of glycaemic excursions (MAGE) was 3.0 mmol/l during GCIIS-control, and 3.3 mmol/l during combined infusion. The GCIIS was found capable of calculating the 24-hour insulin dose in well-known, unstable diabetics; however, it did not improve the preprogrammed insulin infusion profile obtained by the MIIP.