The definitive suppression test to prove autonomous production of growth hormone is

The definitive suppression test to prove autonomous production of growth hormone is

• A. Oral glucose loading
• B. Somatostatin infusion
• C. Estrogen priming
• D. Dexamethasone suppression

Answer: (A)

The test relies on how growth hormone responds to glucose. In healthy individuals, a glucose load triggers a rapid drop in GH because glucose-induced signals suppress pituitary release. If GH remains high after the glucose load, it indicates autonomous, non‑regulated GH production, as seen with GH-secreting pituitary tumors. So the glucose tolerance approach is the definitive way to prove autonomous GH production, since it directly challenges the regulatory control of GH secretion and shows whether suppression occurs. The other options don’t specifically demonstrate autonomous GH production: suppressing GH with somatostatin is a therapeutic/response test, while dexamethasone suppression tests are for cortisol control, and estrogen priming isn’t a standard test for GH autonomy.

The test relies on how growth hormone responds to glucose. In healthy individuals, a glucose load triggers a rapid drop in GH because glucose-induced signals suppress pituitary release. If GH remains high after the glucose load, it indicates autonomous, non‑regulated GH production, as seen with GH-secreting pituitary tumors.

So the glucose tolerance approach is the definitive way to prove autonomous GH production, since it directly challenges the regulatory control of GH secretion and shows whether suppression occurs. The other options don’t specifically demonstrate autonomous GH production: suppressing GH with somatostatin is a therapeutic/response test, while dexamethasone suppression tests are for cortisol control, and estrogen priming isn’t a standard test for GH autonomy.