Synonyms

Sex Hormone Binding Globulin

Clinical Indications

SHBG is the major serum testosterone binding protein and binds over 70% of testosterone. SHBG levels are suppressed by increased androgen levels and elevated by increased oestrogen (e.g. during pregnancy or treatment with some oral contraceptives). The primary reason for measurement of SHBG is to calculate free androgen status from total tesosterone levels and is useful if total testosterone levels are borderline. SHBG levels are not helpful in discriminating between groups of patients with suspected androgen excess.
SHBG levels are elevated in thyrotoxicosis and decreased in hypothyroidism and SHBG may be used as a marker of thyroid status in patients with thyroid hormone resistance. 

Request Form 

Combined Pathology Blood form (Yellow/Black or Blue for GP's)

Availability

Analysed by referral laboratory if specific criteria met.

Specific Criteria

Female total testosterone greater than 1.5 nmol/L. Assessment of thyroid status in thyroid hormone resistance. Otherwise if requested by Consultant Endocrinologist or agreed with Consultant Biochemist.

Turnaround Time

2 weeks

Specimen

Serum

Volume

0.5 mL

Container

Yellow top (SST) tube

Lab. Handling

Aliquot and store at 4C. (SHBG & analyse; NOSBG & save)

Causes for Rejection

Not meeting specific criteria for analysis. Unlabelled sample.

Reference Range

Males: 15.0 - 103.0 nmol/L; Females 19.0 - 117.0 nmol/L.
If total testosterone measured a free androgen index (FAI) will be calculated and reported. FAI: Males 25 - 120; Females <7.5