Male hypogonadism
the failure of the testes to produce testosterone, sperm or both
features of Male hypogonadism
small testes, decreased libido, erectile dysfunction, loss of pubic hair, decreased muscle bulk, increased fat, gynaecomastia, osteoporosis, low mood.
If pre-pubertal: decreased virilization, incomplete puberty, enuchoid body, reduced secondary sex characteristics.
primary Male hypogonadism
due to testicular failure - high LH and FSH and low testosterone
causes of primary Male hypogonadism
congenital: Klinefelter’s etc
acquired:
- testicular tortion/trauma
- chemo/irradiation
post-orchitis eg mumps, HIV, leprosy
renal failure, liver cirrhosis or alcohol excess
secondary Male hypogonadism
decreased gonadotrphins (LH and FSH) and low testosterone
causes of secondary Male hypogonadism
- Congenital/idiopathic: IHH (including Kallman’s and CAH)
- Hypopituitarism
- Hypothalamic or pituitary tumours (prolactinoma – hyperprolactinemia)
- Kallman’s syndrome
- Systemic illness (e.g. COPD, HIV), exercise, weight changes, stress
- Infiltrative disease, e.g. sarcoidosis, haemachromatosis
- Cranial irradiation/trauma
- Drugs e.g. anabolic steroids, opiates
- Prader-Willi syndrome
*
- Prader-Willi syndrome
if someone presents with signs and symptoms of hypogonadism, what does one do
measure total testosterone concentration in semen in morning
if testosterone is normal, hypogonadism is unlikely
if <9.7/10.4 nmol/L, repeat measurement and also measure SHBG
if still low, measure LH and FSH
= primary/secondary hypogonadism
Klinefelter’s syndrome
the most common congenital cause of primary hypogonadism in men
47XXY or mosaicism
what are the clinical features of Klinefelter’s syndrome
reduced testicular volume (small testes)
gynaecomastia
eunuchoidism
decreased cognition, libido and sexual maturation
azoospermia
eunuchoidism
tall with disproportionate arms and legs
indicating low levels of testosterone
azoospermia
semen contains no sperm due to lack of transport via the vas deferens, is assoicated with infertility
Klinefelter’s syndrome
testosterone replacement in men
there is clear evidence for this in young men
the evidence for it in older men is less robust
there is controversy on the role of testosterone on CV risk
will testosterone restore fertility
no
it may act as a contraceptive due to the inhibitory actions on FSH and LH
health benefits of testosterone
improved sexual function: improved erectile function
bone health: improved spine and hip BMD
body composition/muscle strength - decreaesd fat mass and improved limb strength
QOL and cognition
