A 45-year-old woman was being regularly reviewed in primary and secondary care because of a 5-year history of type 2 diabetes that had required early insulin treatment, refractory hypertension, and subsequent chronic kidney disease. She had previously described other symptoms, including weight gain, bruising, flushes, and low mood, all of which had been attributed to obesity and menopause. She was not taking any glucocorticoids. After presenting to her local emergency department with a Colles' fracture after a low impact fall, she was referred to the endocrinology department for suspected Cushing syndrome. Analysis for which of the following would be most useful in confirming the initial diagnosis?

Question

Quizplus · Accepted Answer

The Answer is B
EXPLANATION: The primary symptoms of Cushing syndrome result from the tissues being exposed to high levels of cortisol for too long. The most common cause of Cushing syndrome is a pituitary adenoma that secretes excess amounts of ACTH. ACTH stimulates the adrenal cortex to synthesize the glucocorticoids, primarily cortisol. Therefore, measurement of elevated plasma ACTH levels can indicate Cushing syndrome. Because ACTH induces cortisol production one would expect to see elevated urinary cortisol in addition to the elevated plasma ACTH.

A 45-Year-Old Woman Was Being Regularly Reviewed in Primary and Secondary