male hypogonadism

Question 1

what does FSH do in males?

Answer 1

• act on Sertoli cells for spermatogenesis

- Sertoli cells release inhibin for negative feedback (turn off FSH)

Question 2

what does LH do in males?

Answer 2

• LH works on Leydig cells to secrete testosterone

- Leydig cells produce free testosterone which works for negative feedback

Question 3

what produces testosterone?

Answer 3

Leydig cells

Question 4

what is the majority of testosterone bound to?

Answer 4

SHBG

Question 5

what is testosterone converted into?

Answer 5

dihydrotestosterone and oestradiol

Question 6

what is male hypogonadism?

Answer 6

a clinical syndrome compromising of signs, symptoms and biochemical evidence of testosterone deficiency

Question 7

who is male hypogonadism more common in?

Answer 7

men aged 40-79

Question 8

what is primary hypogonadism?

Answer 8

-hypogonadism caused by the testes being primarily affected

Question 9

what occurs to testosterone and negative feedback in primary hypogonadism?

Answer 9

• decreased testosterone

- decreased negative feedback

Question 10

what occurs to FSH levels and LH levels in primary hypogonadism and why?

Answer 10

-decreased testosterone production so decreased negative feedback and so higher amounts of FSH and LH

Question 11

what is hypergonadotrophic hypogonadism?

Answer 11

primary hypogonadism

its when the testes aren’t working well so there is decreased testosterone but there are increased amounts of LH and FSH

Question 12

how does primary hypogonadism tend to affect testosterone production and spermatogenesis?

Answer 12

spermatogenesis is more affected than testosterone production

Question 13

what is secondary hypogonadism?

Answer 13

-the hypothalamus/pituitary is affected but the testes can still function normally

Question 14

what are the testosterone, FSH and LH levels like in secondary hypogonadism?

Answer 14

LH/FSH levels are low/ inappropriately normal (should be high)
testosterone is low

Question 15

what is hypogonadotrophic hypogonadism?

Answer 15

secondary hypogonadism

• testosterone low
• FSHLH low or inappropriately normal

Question 16

how does secondary hypogonadism tend to affect testosterone production and spermatogenesis?

Answer 16

they seem to be equally effected

Question 17

what are some congenital causes of primary hypogonadism?

Answer 17

Klinefelter’s syndrome
Cryptorchidism
Y-chromosome micro deletions

Question 18

what are some acquired causes of primary hypogonadism?

Answer 18

• testicular trauma/torsion
• chemotherapy/radiation
• varicocele
• orchitis (mumps infection)
• infiltrative disease (e.g. haemochromatosis)
• medications (glucocorticoids, ketoconazole)

Question 19

what is the most common genetic cause of hypogonadism?

Answer 19

Klinefelter’s syndrome

Question 20

what causes Klinefelter’s syndrome?

Answer 20

• genetic

- not inherited caused by nondisjunction

Question 21

How is Klinefelter’s syndrome diagnosed?

Answer 21

by Karyotyping

Question 22

how does Klinefelter’s syndrome present in men?

Answer 22

• affected men are typically infertile due to tubular damage and have small, firm testes
• wide hips
• long arms and legs
• female type pubic hair pattern
• breast development
• tendancy to grow fewer chest hairs
• narrow shoulders
• poor beard growth
• absent frontal baldness
• learning difficulties
• psychosocial issues
• cryptochordism

Question 23

what does Klinefelter’s syndrome increase your chances of developing?

Answer 23

• breast cancer

- non Hodgkin lymphoma

Question 24

what are some congenital causes secondary hypogonadism?

Answer 24

• Kallmann’s syndrome (isolated hypogonadotrophic hypogonadism)
• Prader Willi syndrome

Question 25

what are some acquired causes of secondary hypogonadism?

Answer 25

- pituitary disease (tumours, infiltrative disease, infection, apoplexy, head trauma) - hyperprolactinaemia - obesity - diabetes - medication (steroids, opiates) - acute systemic illness - eating disorders, excessive exercise

Question 26

what is Kallmann's syndrome?

Answer 26

-genetic disorder characterised by isolated GnRH deficiency and hyposmia or anosmia

Question 27

what is isolated GnRH deficiency associated with?

Answer 27

- unilateral renal agenesis (missing kidney) - red green colour blindness - cleft lip/palate - bimanual synkenesis

Question 28

who does Kallmanns syndrome tend to affect?

Answer 28

males but less commonly can affect females

Question 29

what are some pre pubertal onset signs/symptoms of hypogonadism?

Answer 29

Pre pubertal onset: - small male sexual organs, penis and prostate - decreased body hair, low libido, high pitched voice - gynaecomasyia - tall, slim, long arms and legs - decreased bone mass and muscle mass +/- symptoms due to cause

Question 30

what are some post pubertal signs/symptoms of hypogonadism?

Answer 30

- normal skeletal proportion, penis/prostate size and voice - decreased libido, decreased spontaneous erections - decreased pubic/axillary hair, reduced shaving frequency - decreased testicular volume - gynaecomastia - decreased muscle and bone mass - decreased energy and motivation +/- symptoms due to cause

Question 31

how is hypogonadism diagnosed?

Answer 31

- signs/symptoms of low testosterone - measure AM testosterone - if low repeat AM testosterone test - measure LH/FSH - if elevated could be primary hypogonadism (hypergonadrotrophic hypogonadism) so do karyotypic and iron studies - if FSH or LH decreased/inappropriately normal then it could be secondary hypogonadism (hypogonadotrophic hypogonadism) so exclude medications, measure prolactin and pituitary hormones, MRI and iron studies

Question 32

what type of testosterone is active?

Answer 32

free testosterone

Question 33

what can increase SHBG (sex hormone binding globulin)?

Answer 33

- ageing - hyperthyroidism - hyperoestrogenaemia - liver disease - HIV - use of anticonvulsants

Question 34

what are some advantages of testogel?

Answer 34

- fast onset - convenient - mimics circadian rhythm

Question 35

what are some disadvantages of testogel?

Answer 35

- skin irritation is possible - interpersonal transfer - non compliance long term

Question 36

what are some advantages of testosterone undecanoate (oral testosterone)?

Answer 36

-conveniant

Question 37

what are some disadvantages of testosterone undecanoate (oral testosterone)?

Answer 37

- variable testosterone levels - daily or twice daily commitment - many people experience nausea

Question 38

what are advantages of testosterone undecanoate e.g. Nebido (intra-muscular injection)?

Answer 38

- steady testosterone levels - conveniant - lower frequency administration improves complicance

Question 39

what are the disadvantages of testosterone undecanoate e.g. Nebiso (intra muscular injection)?

Answer 39

- difficult to withdraw if side effects experiecnes - local pain at injection side - coughing following injection - contraindicated in blood disorders

Question 40

what are some advantages of testosterone enanthate/proprionate.cipionate e.g. sustain (intra muscular injection)?

Answer 40

- easy to withdraw if side effects experienced | - can be self administered

Question 41

what are some disadvantages of testosterone enanthate/proprionate.cipionate e.g. sustain (intra muscular injection)?

Answer 41

- variable testosterone levels - coughing following injection - local pain at injection site - contraindicated if bleeding disorders

Question 42

what are contraindications for testosterone replacement therapy?

Answer 42

- confirmed hormone responsive cancer (e.g. prostate/ breast) - possible prostate cancer (e.g. raised PSA, suspicious prostate on DRE) - Haematocrit >50% - severe sleep apnoea/heart failure

Question 43

what is done to monitor testosterone replacement therapy?

Answer 43

3-6 monthly whilst starting treatment, annually thereafter - general health and testosterone concentration - DRE and PSA - Haematocrit - symptoms of sleep apnoea