Wallach's Interpretation of Diagnostic Tests: Pathways to Arriving at a Clinical Diagnosis (648 page)

   Diagnosis of and monitoring therapeutic response in CAH due to 11β-hydroxylase deficiency

   Assessment of adrenal response in the metyrapone test; result after metyrapone stimulation is >8,000 ng/dL

   Interpretation

Increased In

   Values are increased in CAH (P450cII deficiency) and following metyrapone administration in normal persons.

Decreased In

   Values are decreased in adrenal insufficiency.

   Limitations

   Patients with myxedema, some pregnant patients, and those on oral contraceptives respond poorly during the test.

17α-HYDROXYPROGESTERONE

   Definition

   17α-Hydroxyprogesterone, also known as hydroxyprogesterone, is a 21-carbon steroid produced in the adrenals—and also in the ovaries, testes, and placenta—that serves as a biosynthetic precursor to cortisol.

   
Normal range:
18–469 ng/dL (see Table 16.1).

TABLE 16–1. Range of Normal Values for 17a-Hydroxyprogesterone

   Use

   Diagnosis and management of congenital adrenal hyperplasia, hirsutism, and infertility