Sex Hormone Binding Globulin
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 on ICE
Analysed if specific criteria met.
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
Serum in yellow top (SST) tube
Causes for Rejection
Not meeting specific criteria for analysis.
Unlabelled or inadequately labelled sample.
Males < 49ys: 18-54
Males > 50yrs: 21-77
Females < 49yrs: 32-128
Females > 50yrs: 27-128