The metabolic response to glycemic control by the artificial pancreas in diabetic man

To determine the effect of glycemic control by the artificial pancreas on the other metabolic consequences of diabetes, five renebese male insulin-dependent diabetic subjects were studied first on s.c. insulin and then during artificial pancreas (AEP) control. Glycemia was continuously monitored, and the circulating concentrations of factate, pyruvate, alanine, free fatty acids (FFA), beta hydroxybutyrate, and triglycerides were measured during breakfast, lunch, snack, and supper. The metabolic profiles were compared to normal control subjects. Glycemic excursion with meals during AEP control was normalized (min, 76 ± 8 mg/dl; max, 157 ± 20 mg/dl), compared to administration of s.c. insulin (min, 173 ± 52; max, 279 ± 49 mg/dl). Postabsorptive concentrations of lactate and pyruvate were elevated for diabetic subjects on s.c. insulin treatment and during AEP control. However, the postmeal peaks of lactate and pyruvate observed in the normal control individuals were restored during AEP control. Although alanine concentrations were similar for all groups at the start of the experiment, the postprandial increase that occurred with breakfast for the normal subjects was delayed until lunch for both diabetic groups. The elevated FFA concentrations with s.c. insulin were entirely normalized during AEP control, whereas beta hydroxybutyrate concentrations were incompletely corrected. These studies demonstrate that a short period of glycemic control during meals restores toward normal other metabolic intermediates influeneed by insulin. For further refinement in metabolic control, a more prolonged period of normoglycemia may be required.