Turnaround times
The quoted turnaround time is from sample receipt in the laboratory, to results authorisation in the Laboratory Information Management system. The times do not include transport of specimen to the laboratory or the administrative process to print and post/email reports. Service users must allow for transport and reporting time when ordering tests.
Clinical background:
SHBG is a glycoprotein, synthesized in the liver and responsible for both transport and regulation of activity of the sex steroids testosterone and oestradiol. The activity of testosterone and oestradiol is thought to be due to the unbound fractions. SHBG has a single binding site for these steroid hormones. The production of SHBG is increased by oestrogens (and thyroxine) and decreased by androgens. This effect, combined with a greater affinity for testosterone than oestradiol, will modulate the physiological action of either testosterone or oestradiol and hence the sex hormone balance.
If oestradiol production increases, the unbound (physiologically active) oestradiol rises and SHBG production is stimulated. This causes a differential fall in unbound testosterone, tipping the sex hormone balance further in favour of oestradiol e.g. as in pregnancy. An increase in testosterone production, by causing a fall in SHBG, will amplify its own effect leading to a differential rise in unbound (physiologically active) testosterone relative to oestradiol, as in males. Of particular value is the determination of SHBG levels in the investigation of hirsutism/hyperandrogenism in females where low levels of SHBG may be found.
Specimen container paediatric:
Serum (SST or plain tube)
Specimen container adult:
Serum (SST or plain tube)
Minimum volume paediatric:
1 mL blood
Minimum volume adult:
1 mL blood
Sample stability:
Unseparated sample:
unknown
Separated sample:
unknown at 15-25°C, 7 days at 2-8°C, 1 month at -20°C
Transport requirements:
Ambient
Interpretation:
Raised levels of SHBG are found in:
Pregnancy
Thyrotoxicosis
Gynaecomastia
Male
Hypogonadism
Liver Cirrhosis
Type 1 Diabetes Mellitus
Decreased levels of SHBG are found in:
Hirsuitism
Polycystic Ovarian Syndrome(PCOS)
Acromegaly
Cushing’s Disease
Type 2 Diabetes Mellitus
Hepatic Steatosis
Reference ranges:
Male:
Up to 20 years: No information available
20 to 49 years: 18 – 54 nmol/L
50 years and over: 21 – 77 nmol/L
Female:
Up to 20 years: No information available
20 to 49 years: 32 – 128 nmol/L
50 years and over: 27 – 128 nmol/L
Other info:
Lithium heparin plasma samples also acceptable