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Testosterone (serum) (515)

Women: Virilising conditions of any kind (hirsutism, virilism).
Men: Reduced testicular function, impotence, infertility, andropause.
Children: Precocious or delayed puberty.

Sample material

Coagulated blood 9 (3) mL or serum 4 (1) mL.

Analysis number

515

Response time

Results are reported 1-2 weeks after sample reception.

Interpretation

Women: Elevated serum levels are seen in ovarian hirsutism. Normal or marginally elevated levels are seen in adrenal hirsuitism. Normal levels are seen in Constitutional hirsuitism.
Men: Reduced serum testosterone concentration shows that internal secretion within the testis is reduced. A function test can be performed by measuring testosterone levels before and after stimulation with human chorionogonadotrophin (HCG test). 3,000 IE HCG daily for 5 days produces a measurable elevation of serum testosterone provided that there are functional cells present.
Children: Elevated levels are often seen in precocious puberty.

Remarks

Measurement of LH, FSH, Oestradiol and/or PRL together with testosterone can be indicated.

Result

units nmol/L.

Measurement range and Imprecision 

 Range  Imprecision
 0.1 - 100 nmol/L  < 15 % over 0.5 nmol/L
 < 20 % under 0.5 nmol/L

Reference values

The reference ranges are 2.5 and 97.5 percentiles for normal. Mean values are calculated logarithmically.

 Age (years) and Sex   Mean  Range
 Women Pre menopause  1.0 nmol/L  0.55 - 1.8 nmol/L
 Post menopause  0.94 nmol/L  0.52 - 1.7 nmol/L
 Children < 10  0.28 nmol/L  0.10 - 0.69 nmol/L
 Puberty  Variable, dependant upon level of development
 Men 20 - 50  16.8 nmol/L  10.3 - 27.4 nmol/L
 Men 50 - 70  14.6 nmol/L  8.4 - 25.4 nmol/L
 Men > 70  11.8 nmol/L  6.2 - 21.8 nmol/L

Timing of sampling

Testosterone shows little diurnal variation, but the sample should be taken before noon.

Methodology

Testosterone (proteinbound and free) is extracted from serum and measured using chromatography connected to tandem mass spectrometry. This eliminates any matrix effect and is extremely specific, making this method suitable for all biological material.
The result is reported in nmol pr. litre serum. To convert to the older unit, ng/100 ml, multiply by 28.8.

Last revised 19 December 2013

Further information

Clinical Biochemistry, Immunology & Genetics
Hormone Laboratory

Tel: +45 3268 3262