Insulin Receptor Changes in Type 2 Diabetes after Short Term Insulin Treatment

Summary

We have studied erythrocyte insulin receptor changes before and after 8 days of continuous subcutaneous insulin infusion by a pump in 11 uncontrolled obese non-insulin-dependent diabetics (type 2), diet and drug resistant for at least three months previously. All the patients were hospitalized. On day 1 of the study, their oral hypoglycemic agents were stopped and hypocaloric diet (1000 Kcal/day) was maintained (strictly reinforced). This period of reinforced treatment was not accompanied by correction of hyperglycemia. On day 9 patients were placed for 12 hours on artificial pancreas in order to bring their fasting blood glucose levels down to normal values. Then they were submitted to a continuous subcutaneous insulin infusion (CSII) for the following 8 days. There was a significant decrease in mean fasting plasma glucose (P < 0.001) and a rise in insulin (P < 0.05) levels after insulin treatment. Mean specific insulin binding was also significantly increased (P < 0.01). The increase in binding (with insulin therapy) correlated with the fall in fasting hyperglycemia (r = 0.786, P < 0.01). In addition, the increase in binding correlated negatively with changes in fasting plasma insulin levels (r = -0.867, P < 0.01), under treatment, on one hand and with the dose of exogenous insulin administered (r = -0.681, P < 0.05) on the other hand. There was no correlation between binding and fasting plasma insulin levels (before and after insulin therapy), or between diabetes duration and any of the previous parameters. We concluded that insulin therapy for 8 days in this uncontrolled diet and drug resistant subgroup of type 2 diabetics leads to an increase in the mean binding to erythrocytes and to correction of blood glucose levels. This improvement seems to be related to changes in fasting plasma insulin and plasma glucose levels and to the dose of insulin delivered by the pump. The increase in binding was mainly due to CSII rather than due to stricter adherence to the hypocaloric diet.

Key-Words:

Insulin Receptors - Erythrocytes - Type 2 Diabetes - Insulin Treatment - Artificial Pancreas - CSII