Male Hypogonadism

Question 1

what stimulates release of GnRH from the hypothalamus?

Answer 1

kisspeptin

Question 2

what does GnRH do?

Answer 2

stimulates the anterior pituitary to release LH and FSH

Question 3

what effect do LH and FSH have in males?

Answer 3

testes stimulated to produce testosterone

Question 4

what cells produce testosterone and what hormone controls this?

Answer 4

leydig cells

LH

Question 5

how does the majority of testosterone exist?

Answer 5

bound to SHBG and albumin

only <2% free and bioavailable

Question 6

what two things is testosterone converted to?

Answer 6

dihydrotestosterone

oestradiol

Question 7

what is the highly active form of testosterone?

Answer 7

dihydrotestosterone

Question 8

what breaks down dihydrotestosterone?

Answer 8

5a reductase

Question 9

what breaks down oestradiol?

Answer 9

aromatase

Question 10

what is male hypogonadism?

Answer 10

low or reduced testicular function

clinical syndrome of testosterone deficiency

Question 11

what type of male hypogonadism is caused by a problem with the testes?

Answer 11

primary

Question 12

what type of male hypogonadism is caused by a problem with the hypothalamus or pituitary?

Answer 12

secondary

Question 13

what hormone level abnormalities are seen in primary hypogonadism?

Answer 13

low testosterone

raised LH/FSH

Question 14

what is another name for primary hypogonadism?

Answer 14

hypergonadotrophic hypogonadism

Question 15

how can primary hypogonadism present and why?

Answer 15

to fertility clinics, as spermatogenesis is affected

Question 16

name three congenital causes of primary hypogonadism

Answer 16

klinefelte’s syndrome
cryptorchidism
Y chromosome microdeletions

Question 17

name some acquired causes of primary hypogonadism

Answer 17

testicular trauma 
chemotherapy 
varicocele 
orchitis 
infiltrative disease 
medications

Question 18

name an infiltrative disease that can cause primary hypogonadism

Answer 18

haemochromatosis

Question 19

what type of infection can commonly cause orchitis?

Answer 19

mumps

Question 20

name two medications that can cause primary hypogonadism

Answer 20

glucocorticoids

ketoconazole

Question 21

what causes klinefelter’s syndrome?

Answer 21

nondisjunction

47 XXY

Question 22

how is klinefelter’s syndrome diagnosed?

Answer 22

karyotyping

Question 23

how does klinefelter’s syndrome present?

Answer 23

infertile

small, firm testes

Question 24

what is there an increased risk of in patients with klinefelter’s syndrome?

Answer 24

cryptorchidism
learning disablities
breast cancer
non-hodgkin lymphoma

Question 25

describe the hormone levels seen in secondary hypogonadism

Answer 25

low/inappropriately normal LH/FSH | low testosterone

Question 26

what is another name for secondary hypogonadism?

Answer 26

hypogonadotrophic hypogonadism

Question 27

name two congenital causes of secondary hypogonadism

Answer 27

kalman's syndome | prader willi

Question 28

what is another name for kalman's syndrome?

Answer 28

isolated hypogonadotrophic hypogonadism

Question 29

name some acquired causes of secondary hypogonadism

Answer 29

``` pituitary damage hyperprolactinaemia diabetes medications acute illness eating disorders ```

Question 30

name two medications that can cause secondary hypogonadism

Answer 30

steroids | opioids

Question 31

what is kalman's syndrome?

Answer 31

a genetic disorder characterised by isolated GnRH deficiency and hyposmia/anosmia

Question 32

what other abnormalities may be seen in kalman's syndrome due to isolated GnRH deficiency?

Answer 32

unilateral renal agenesis red-green colour blindness cleft lip bimanual synkinesis

Question 33

how does hypogonadism present if onset is pre puberty?

Answer 33

``` small sex organs decreased body hair high pitched voice low libido gynaecomastia decreased bone + muscle mass ```

Question 34

how does hypogonadism present if onset is post puberty?

Answer 34

``` normal sexual organs decreased libido + spontaneous erections decreased body hair decreased testicular volume gynaecomastia ```

Question 35

what is the initial test for hypogonadism?

Answer 35

AM testosterone | repeated if low

Question 36

how is testosterone measured?

Answer 36

total testosterone and SHBG measured and used to calculate the calculated free testosterone

Question 37

when should testosterone be measured and why?

Answer 37

between 8-11am peaks in the morning

Question 38

how is male hypogonadism managed?

Answer 38

testosterone replacement therapy

Question 39

what are the four contraindications to testosterone replacement therapy?

Answer 39

hormone responsive cancer possible prostate cancer haematocrit >50% severe sleep apnoea/heat failure