Insulin Tolerance

With the patient in a fasting state, blood sugar is measured followed by IV injection of 0.1 units of insulin/Kg body weight. Blood sugar is subsequently measured at 20, 30, 45, 60, 90, and 120 minutes post injection. In a normal response, blood sugar should drop about 50% within the first 20 minutes, without development of any symptoms, and then slowly rise back to the previous fasting level by 120 minutes. In hypoglycemic individuals, the drop is more precipitous and the recovery slower, and various signs of hypoglycemia may manifest.

In the event of excessive drop in blood sugar leading extreme symptoms or unconsciousness, the doctor must be prepared to immediately administer IV glucose in order to prevent brain damage or death. Individuals with adrenal insufficiency may be more sensitive to insulin, and in this case the insulin dose should be reduced by half [Barnes1999]; [Escamilla1954]; [Starr2005, pg 141].