L19 - Endocrine aspects of male hypogonadism

Question 1

Testosterone

what is it - properties, where is it secreted and by what, how does it exist in the blood

what are the two main anatomical units of the testes

how does it fit into the hypothalamic-pit-testicular axis

what is the mechanism of action for testosterone

what are the actions of testosterone

Answer 1

some albumin, some SHBG
7mg per day
steroid hormone

seminiferous tubules containing sertoli cells
leydig cells in interstitium

androgen target vcells convert T to 5alpha-dihydrotestosterone before it binds. or armoatised to eostrogens

Question 2

what are the two hypes of hypogonadism and what are causes for both

what are the hormones levels like for each type

Answer 2

primary (testes)
—-T below normal, LHandFSH high
klinifelters, cryptochordism, infection, radiation, trauma, torsion, idiopathic

secondary (hypothalamus/pituitary)

• –T low and LH, FSH low
• –congenital GnRH def, hyperprolactinemia, GnRH analog, androgen, opiodes, illness, anorexia nervosa, pit disorder

Question 3

what are clinical features of hypogonadism

1st trimester/ 3rd / prepubertal / adults

less sp symptoms and signs
what are conditions with a high prev of hypogonadism?

what do you examine for

Question 4

what investigations would you do

for screening, what do you need to be careful of?

SHBG - what lowers and raises it

Answer 4

T high in morning
normal t age dep

confirmation - repeat morning total t

do not screen during acute illness - may lower t temp

SHBG
lowers - obesity, nephrotic syndrome, hypothyroidism, glucocorticoid use (or progestins, androgenic steroids)

raises - ageing, hepatic currhosis, hyperthrupidosm, anticonvulsants, estrohens, HIV infection

Question 5

what treatment can be offered

what do you monitor

what are contraindictions to this therapy

Answer 5

Testisterone gel, injection, buccal / patch

Question 6

GYNECOMASTIA

what is it diagnosed as
causes

evaulation - what do you think when examining. also history

what do you look for on examination

investigations?

treatment?

Answer 6

at least 0.5cm.
it is benign proliferation of glandular tissue of the male breast

tamoxifen
surgery