Which of the following findings is NOT associated with Cushing's disease?

Cushing's disease is characterized by an overproduction of cortisol typically due to an ACTH-secreting pituitary adenoma. One of the hallmark findings in patients with Cushing's disease is the elevated levels of ACTH as the body attempts to stimulate the adrenal glands to produce cortisol. Consequently, a high ACTH level is expected in this condition.

Additionally, patients with Cushing's disease will not show suppression of cortisol production in response to a low-dose dexamethasone suppression test, indicating a failure of feedback inhibition. They may require multiple antihypertensive agents to manage hypertension, as cortisol excess can lead to significant hypertension due to its effects on fluid retention and vascular tone.

In contrast, administering a high dose of dexamethasone typically results in cortisol suppression in cases of Cushing's disease. This is because, in conditions like Cushing's disease, the feedback mechanisms may still allow for some suppression if the source of cortisol is pituitary in origin, especially when enough dexamethasone is administered to suppress ACTH secretion. A lack of cortisol suppression with high-dose dexamethasone administration would suggest an adrenal source of excess cortisol or ectopic ACTH syndrome, rather than Cushing's disease itself.