Androgens

Question 1

Causes of reduced SHBG

Answer 1

nephrotic syndrome
moderate obesity
diabetes
hypothyroidism
glucocorticoid, progestins
acromegaly

Question 2

Causes of increased SHBG

Answer 2

ageing
cirrhosis/hepatitis!!
hyperthyroidism
use of anticonvulsants
HIV
Use of oestrogens

Question 3

Some causes of low testosterone? Group based on LH/FSH values?

Answer 3

Primary with increased FSH, LH

• testicular damage from toxins, radiotherapy, spironolactone/ketoconazole
• congenital because of kleinfelter, myotonic dystrophy, cryptorchism, LH/FSH receptor mutations

Secondary with low/normal FSH or LH

• tumour pit/hypothal, surgery, infiltration eg iron sarcoid,
• genetic from Kallmanns syndrome
• functional from HIGH PROLACTIN, morbid obesity, cushings syndrome
• acute illness, ESRF, HIV, DM2
• steroids, opioids, GnRH agonists, anabolic steroids

Question 4

Where do LH and FSH act?

Answer 4

LH acts on leydig cell LH-receptor–>tesosterone

FSH acts on Sertolic cell FSH-R–>spermatogenesis

Question 5

How to interpret prolactin values?

Answer 5

More than 5-10 x ULN almost always a prolactinoma

Up but less than 5 x ULN–>stalk effect and macroprolactin

Question 6

Frequency of what is coming out of a pituitary adenoma

Answer 6

prolactin >non functioning >GH > ACTH