Glucagon tolerance test in glycogen storage disease

Abstract

Summary 1. Glucagon injected intravenously in a patient with generalized glycogen storage disease produces a normal rise in blood sugar, even in a starving state. Such a blood sugar response excludes the possibility of von Gierke's disease and of Cori's disease. 2. Glucagon injected intravenously in a patient with either von Gierke's disease or with Cori's disease does not produce a normal rise in blood sugar provided the patient has been kept starving. 3. Glucagon injected intravenously in a patient with von Gierke's disease does not produce a rise in blood sugar even when done 2 hours after the patient has been given a substantial meal. 4. Glucagon injected intravenously in a patient with Cori's disease does produce a normal rise in blood sugar provided the patient has been given a substantial meal two hours prior to testing. 5. It is important to starve the patient long enough (not less than 14 hours) prior to the second glucagon tolerance test. Thus, a sufficient degradation of the outer branches of the glycogen molecule in Cori's disease is assured. Normal individuals react with a normal glucagon tolerance curve even after 48 hours of starvation. No other metabolic disorders are presently known which might interfere with this test. Equivocal results can be obtained in cases where the deficiency of glucose-6-phosphatase is only moderate. The more rare forms of glycogen storage disease (other than Types 1 and 3) can only be ruled out with the test.