Sample stability:
-
5 days at 20-25 o C
-
14 days at 2-8 o C
-
12 months at -20 o C
This test may be vetted by a pathologist.
The clinical information for the test must be clearly written on the request form. If clinical information is not provided, or does not provide sufficient justification for the test, the test may be declined.
Declined tests :
If a test is declined, the specimen will be held for a reasonable period (usually 3 weeks but dependant on the stability of the sample). Medical practitioners seeking approval for a declined test should email the on-call Chemical Pathologist ( chemicalpathologist@adhb.govt.nz ) , giving the patient's name and NHI number and the clinical justification for the test. If unable to email, call the on-call Chemical Pathologist via Lablink (09-3078995) and identify yourself as a doctor.
Units : umol/L
Reference ranges:
|
Age |
Lower |
Upper |
|
Males & Females |
|
|
|
<7 days |
2.7 |
20.4 |
|
7 to <28d |
0.80 |
13.6 |
|
28d to <1y |
0.06 |
6.7 |
|
1y to <5y |
0.01 |
0.70 |
|
5 to <10y |
0.06 |
2.6 |
|
Females |
|
|
|
10 to <15Y |
0.68 |
8.8 |
|
15 to <20y |
1.4 |
11.5 |
|
20 to <25y |
3.9 |
11.6 |
|
25 to <35y |
1.9 |
11.0 |
|
35 to <45y |
1.5 |
10.9 |
|
45 to <55y |
0.80 |
8.7 |
|
55 to <65y |
0.44 |
8.0 |
|
65 to <75y |
0.23 |
7.5 |
|
= or >75y |
0.19 |
4.5 |
|
Males |
|
|
|
10 to <15y |
0.41 |
7.6 |
|
15 to <20y |
1.4 |
14.3 |
|
20 to <25y |
5.1 |
13.6 |
|
25 to <35y |
4.0 |
13.9 |
|
35 to <45y |
1.8 |
12.6 |
|
45 to <55y |
1.0 |
10.0 |
|
55 to <65y |
1.0 |
8.6 |
|
65 to <75y |
0.88 |
7.0 |
|
= or >75y |
0.41 |
5.7 |
The reference intervals quoted are derived from references 1 to 5 below.
Uncertainty of Measurement: 12% below the level of 1.0 umol/L
8% at the level of 5.50 umol/L and higher
Performed once a week.
Following pathologist approval.
Principle: Competitive type immunoassay with chemiluminescence detection
Reagents: Roche DHEA-S kit
Analyser: Cobas e801
DHEAS is an androgenic steroid, mainly of adrenal origin. Its main diagnostic use is as a marker of an adrenal tumour. Minor elevations are common in polycystic ovary syndrome and idiopathic hirsutism, but DHEAS measurement has no diagnostic value in these conditions. In this context, the key androgen to measure is testosterone (1).
Investigations for hirsutism in women (ref. 1)
Mild hirsutism of slow onset without other signs of androgen excess (acne, clitoromegaly or muscularity), menstrual irregularity or infertility does not require measurement of testosterone or any other androgen.
In women with moderate or severe hirsutism or hirsutism of any degree when it is sudden in onset, rapidly progressive, or associated with other abnormalities such as menstrual dysfunction, obesity, or clitoromegaly, a testosterone level is recommended.
If the testosterone level is raised, the commonest cause is PCOS. To exclude other conditions the following investigations are suggested:
-
measurement of prolactin, DHEAS (to exclude an adrenal tumour) and 17-hydroxyprogesterone (to exclude late-onset 21-hydroxylase deficiency)
-
pelvic ultrasonography to detect an ovarian neoplasm or a polycystic ovary
Other uses of DHEAS measurements
DHEAS may be helpful in the investigation of ambiguous genitalia and differentiation between different types of congenital adrenal hyperplasia.
DHEAS is been reported to be helpful in differentiating the cause of Cushing's Syndrome:
- Pituitary Cushing's: DHEAS normal or slightly increased.
- Adrenal adenoma or exogenous glucocorticoids: DHEAS undetectable
- Adrenal carcinoma: DHEAS typically > 20 umol/L
Changes in DHEAS levels with age
Adrenal androgen production reaches a peak between 20 and 30 years of age and then gradually falls with age to about 20% of peak levels after 70 years. This is in contrast to cortisol production, which does not change with age. This so-called "andropause" is a normal physiological process. There is no good evidence that DHEA supplements offer any benefits, or that measuring DHEAS is of any value in assessing the need for such supplements. DHEAS tests are of no clinical value in patients taking DHEA supplements or glucocorticoids .
The advantages of measuring DHEAS, rather than DHEA:
The half-life of DHEAS is 8 to 11 hours, whereas it is only 30 to 60 minutes for DHEA. The short half-life and episodic release of DHEA make levels difficult to interpret. In contrast, DHEAS has no major diurnal fluctuation.
DHEAS tests may be vetted by a pathologist
Requests for DHEAS may be declined if the testosterone level is normal.
Criteria for approval of DHEAS tests
- Investigation of ambiguous genitalia or congenital adrenal hyperplasia.
- Females with high testosterone level , to exclude an adrenal tumour . Repeated DHEAS tests will not be approved.
- Requests from endocrinologists, gynaecologists and dermatologists will be approved.
- Other cases will require discussion with a Labplus chemical pathologist
References :
1. Martin KA, Chang RJ, Ehrmann DA et al. Evaluation and treatment of hirsutism in premenopausal women: an endocrine society clinical practice guideline. J Clin Endocrinol Metab. 2008;93:1105-1120
2. Adrenal steroid response to ACTH: pediatrics. Endocrine Sciences in-house publication. May 1991.2. Mayo Medical Laboratories, 2003 Test Catalogue.
3. DHEAS levels in NZ blood donors measured by Immulite 2000 (2002). Unpublished.
4. Davidson et al. Androgen levels in adult females: changes with age, menopause and oophorectomy. J Clin Endocrinol Metab 90:3847-53, 2005
5. Immulite 2000 reference range compendium, Diagnostic Products Corporation.
6. Orentreich N et al. Age changes and sex differences in serum DHEAS concentrations throughout adulthood. J Clin Endocrinol Metab 59:551-555, 1984
7. Derksen J et al. Identification of virilising adrenal tumours in hirsute women. New Eng J Med 331:968-73, 1994
8. McKenna TJ. Screening for sinister causes of hirsuitism. New Eng J Med 331:1015-6, 1994
9. Legro, R. S., S. A. Arslanian, et al. (2013). "Diagnosis and treatment of polycystic ovary syndrome: an Endocrine Society clinical practice guideline." J Clin Endocrinol Metab 98 (12): 4565-4592.
Emails to chemicalpathologist@adhb.govt.nz will receive priority attention from the on-call chemical pathologist.
If the query concerns a specific patient please include the NHI number in your email.
If email is not a suitable option, please contact the on-call chemical pathologist via Lablink (Auckland City Hospital ext. 22000 or 09-3078995).
Individual chemical pathologists may be contacted but will not be available at all times.
After-hours : contact Lablink (Auckland City Hospital ext. 22000 or 09-3078995) or hospital operator for on duty staff after hours.
Dr Samarina Musaad (Clinical Lead) : SamarinaM@adhb.govt.nz ext. 22402
Dr Cam Kyle: CampbellK@adhb.govt.nz ext 22052
Dr Weldon Chiu: WeldonC@adhb.govt.nz ext. 23427
Dr Campbell Heron: CHeron@adhb.govt.nz ext. 23427
Dr Sakunthala Jayasinghe: Sakunthala@adhb.govt.nz ext. 23427
Send a separated SST tube, or at least 300 uL serum aliquot. Transport at room temp or frozen if sample will be >2 days old on arrival to LabPlus.