Dehydroepiandrosterone Sulphate (DHEAS)

Clinical Chemistry

---

Description

The DHEAS in circulation originates almost entirely from the adrenals, though in men some may also derive from the testes, partly accounting for the difference in serum concentrations between males and females. DHEA is not produced by the ovaries even under pathological conditions. In itself, DHEA is only weakly androgenic, but it can be metabolised to more potent androgens like androstenedione and testosterone, and thus be ( indirectly ) a cause of hirsutism or virilization. Plasma levels of DHEAS increase steadily from about the seventh year of life, then gradually decline after the third decade. Pregnancy and oral contraceptives induce a moderate decrease. DHEAS is secreted into the bloodstream at a rate only somewhat greater than DHEA, but because of its much slower turnover ( DHEAS has a half-life of nearly 24 hours ) it maintains a plasma level almost a thousand-fold higher. Unlike cortisol, DHEAS does not exhibit significant diurnal variation. Unlike testosterone, it does not circulate bound to sex hormone-binding globulin and hence is not influenced by alterations in the level of this carrier protein. Its abundance, together with its within-day and day-to-day stability, makes it an excellent direct indicator of adrenal androgen output ( superior, certainly, to the measurement of urinary l7-ketosteroids in this context ). Accordingly, DHEAS is often assayed in conjunction with free testosterone as an initial screen for hyperandrogenism in hirsutism. At least one of these two hormones is likely to be elevated in the great majority of cases ( reportedly over 80 percent of the time ). Sometimes DHEA-S04 is the only hormone circulating at a level above normal, and is apparently more likely to be elevated during the early stages of hirsutism than most other androgens. High DHEAS levels are often encountered in the polycystic ovary syndrome, showing that adrenal hyperandrogenism is a fairly typical facet of this syndrome. Elevated plasma levels which over the course of two weeks or so are dexamethasone-suppressible may also result from adrenal hyperplasia. Extremely high levels in women are suggestive of a hormone-secreting adrenal tumour. By contrast, DHEAS levels are typically normal in the presence of ovarian tumours.

---

Sample Type

Serum, SST/Gel, minimum 2 mL ( 1 mL of separated serum )

---

Reference Range

Reference ranges are provided on the report. Alternatively, please contact the laboratory for current ranges.

---

Turnaround Time

Within 1 week

---

Testing Frequency

Twice weekly

---

Please note: the above information is subject to change and we endeavour to keep this website up to date wherever necessary.