Reproducibility of Insulin Dosage on Consecutive Days of Blood Glucose Control by an Artificial Beta-Cell in Brittle Diabetic Patients

Abstract

The profiles of blood glucose and of insulin dosage were compared between the first and second of 2 consecutive days of Biostator administration under constant conditions in 12 brittle type I diabetic inpatients. All blood glucose criteria and the daily insulin doses were reproducible between these 2 days for the entire group of patients. In nearly all patients, however, there were distinct but unsystematic differences between the 2 days in the diurnal patterns of insulin dose distribution. These differences could be ascribed to some stress reaction or inherent metabolic lability. It is concluded that, in these extremely labile diabetic patients, due to the insufficient short-term reproducibility of the outcome of an extracorporal artificial beta-cell, caution must be used when constant profiles are to be predicted from these doses for open-loop insulin delivery systems or for conventional subcutaneous injection therapy.

Long-term Improvement in Metabolic Control of Unstable Type I Diabetes by s.c. Insulin Injection Patterns Based on the Dose Profiles Required by Bed-Side Artificial Beta-Cell1)

“…Several attempts to employ the insulin dose patterns from short-term treatment with a bed-side artificial beta cell in metabolic restoration and in optimization of s.c. insulin injection therapy in type I diabetics have been reported (Ratzmann et al, 1982;Beyer et al, 1979;Irsigler et al, 1979;Lambert et al, 1979;Bruns et al, 1983;Christiansen et al, 1979). There are, however, so far no follow-up observations, and most authors have not been able to prove an advantage of this trial.…”

“…Protocol. The regimens of insulin treatment, díet, muscular activity, and also of application of the Biostator® as performed in this hospital have already been extensively described (Bruns et al, 1983;Ratzmann et al, 1983). The first set of control data was provided from the initial period of hospitalization of one to two weeks when the patients had achieved the best possible metabolic control by three injections of regular insulin (Actrapid-MC Novo, Altinsulin Berlin-Chemie), supplemented by one injection of intermediate-acting insulin for the night (Novo-Semilente or Berl-Insulin L Berlin-Chemie).…”

“…Accordingly it has been tried to treat insulin-dependent diabetic patients with a bed-side artificial beta cell while they were kept on their usual s.c. injection regimen and thus to compensate for a specific lack or surplus in the s.c. insulin dosage (Ratzniann et al, 1982). Another approach consists in "normoglycaemic intercalary days" on the extracorporal artificial beta cell without any strong dietary restrictions (Beyer et al, 1979;Irsigler et al, 1979;Lambert et al, 1979;Bruns et al, 1983;Christiansen et al, 1979). This provides both metabolic amelioration and some knowledge of the patient's insulin requirement.…”

Artificial Connection Between Glucose Sensing and Insulin Delivery: Implications of Peritoneal Administration

“…It has been concluded from this study that in the design of an artificial controller the sensing site of glucose is of minor importance compared with the endogenous metabolic interrelations. This holds true as long as the glucose sensor shows sufficient functional biostability and can be reliably calibrated in (20) in a Type I diabetic patient. After restoration of normoglycemia by means of bedside-type artificial beta-cell (GCII), an intravenous bolus injection of glucose and insulin was given against the background of a constant basal insulin infusion.…”

“…This leads to the problem of applying appropriate numerical values of the algorithm parameters. In a previous clinical study on Biostator-treated Type 1 diabetic patients, we have altered the algorithm parameters on an empirical basis from the values recommended by the manufacturer to those that appeared more suitable to the individual patient's needs (20). It turned out that due to this individual adaption of algorithm parameters the insulin doses given by the machine were significantly smaller while blood glucose control remained equally good.…”