Wallach's Interpretation of Diagnostic Tests: Pathways to Arriving at a Clinical Diagnosis (893 page)

   Extremely high levels (>700 or 800 μg/dL) in women are suggestive of a hormone-secreting adrenal tumor. By contrast, DHEA-SO
₄
levels are typically normal in the presence of ovarian tumors.

   There are currently no established guidelines for DHEA-S replacement/supplementation therapy or its biochemical monitoring.

   Many drugs and hormones can result in changes in DHEA-S levels. In most cases, the drug-induced changes are not large enough to cause diagnostic confusion, but when interpreting mild abnormalities in DHEA-S levels, drug and hormone interactions should be taken into account. Examples of drugs/ hormones that can reduce DHEA-S levels include insulin, oral contraceptive drugs, corticosteroids, CNS agents that induce hepatic enzymes (e.g., carbamazepine, clomipramine, imipramine, phenytoin), many antilipemic drugs (e.g., statins, cholestyramine), dopaminergic drugs (e.g., levodopa/dopamine, bromocriptine), fish oil, and vitamin E.

   Drugs that may increase DHEA-S levels include metformin, troglitazone, prolactin, danazol, calcium channel blockers (e.g., diltiazem, amlodipine), and nicotine.

DEHYDROEPIANDROSTERONE, SERUM (DHEA, DHEA UNCONJUGATED)

   Definition

   DHEA has very low androgenic potency but serves as the major direct or indirect precursor for most sex steroids. DHEA is secreted by the adrenal gland, and production is at least partly controlled by ACTH; the bulk of DHEA is secreted as a 3-sulfoconjugate DHEA-S. Both hormones are albumin bound, but DHEA-S binding is much tighter. As a result, circulating concentrations of DHEA-S are much higher (>100-fold) compared to DHEA. In most clinical situations, DHEA and DHEA-S results can be used interchangeably. In gonads and several other tissues, most notably skin, steroid sulfatases can convert DHEA-S back to DHEA, which can then be metabolized to stronger androgens and to estrogens. During pregnancy, DHEA/DHEA-S and their 16-hydroxylated metabolites are secreted by the fetal adrenal gland in large quantities. They serve as precursors for placental production of the dominant pregnancy estrogen, estriol. Within weeks after birth, DHEA/DHEA-S levels fall by 80% or more and remain low until the onset of adrenarche at age 7 or 8 in girls and age 8 or 9 in boys.

   
Normal range
(adults): male: 180–1,250 ng/dL; female: 130–980 ng/dL.

   Use

   Diagnosing and differential diagnosis of hyperandrogenism (in conjunction with measurements of other sex steroids).

   An adjunct in the diagnosis of CAH; DHEA/DHEA-S measurements play a secondary role to the measurements of cortisol/cortisone, 17α-hydroxyprogesterone, and androstenedione.

   Diagnosing and differential diagnosis of premature adrenarche.

   Interpretation