Adrenocortical, somatotropic, and antidiuretic response to nasal glucagon in healthy subjects.

This study investigated the effects of intranasal (IN) glucagon administration on the adrenocortical, somatotropic, and antidiuretic axes in 10 healthy adults, assessing its potential as a diagnostic stimulus test for hypopituitarism. Unlike the established intramuscular or subcutaneous glucagon stimulation test (GST), IN glucagon at a 3 mg dose did not significantly stimulate anterior or posterior pituitary hormone secretion, as measured by adrenocorticotropic hormone (ACTH), cortisol, growth hormone (GH), and copeptin levels. The study also found that IN glucagon induced a hyperinsulinemic response leading to hypokalemia in over half of the participants, a side effect not previously reported with other glucagon administration routes. These findings suggest that IN glucagon, at the tested dose, is not effective for evaluating pituitary function and highlight the need for monitoring potassium levels during its acute use in healthy individuals.