Male Pathophys

Question 1

Hypogonadism

Answer 1

a clinical syndrome that results from failure of testes to produce phys. lvls of T and the nl # of spermatozoa due to disruption of 1/m lvls of the HPG axis

Question 2

Sexual signs of hypogonadism

Answer 2

1. diminished libido
2. erectile dysfxn
3. DIff achieving orgasm
4. decreased performance

*but can present this way even if indiv doesnt have hypogonadism

Question 3

CLue for exogenous androgen exposure

Answer 3

undetectable gonadotropins

Question 4

Pathophys of testosterone deficiency: hypothalamic dysfxn

Answer 4

see slide

Question 5

Genetic causes of GnRH deficiency

Answer 5

Kallman syndrome

Mut in KAL1 at pituitary
- Presents with Anosmia: can’t smell

Question 6

Acquired Central Hypogonadism

Answer 6

Low - low nl LH + FSH
Low T

1. GnRH pulse generator defect due to:
   - stress
   - severe illness
   - abnl weight loss
2. Narcotics:
   - opioids/marijuana: wipe out pulse generator
3. Glucocorticoids:
   - steroid injxn: suppresses adrenal axis and T
4. Supplements:
   - prohormones
   - anabolic steroids: cause undetectable LH/FSH

Question 7

nl T lvls for adult

Answer 7

240-800 ng/dl

Young men: 550 ng/dl
- more SHGB  makes higher total  T lvls 
Older men:
240 ng/dl
- Less SHGB makes a lower total T lvls

Question 8

Causes of ED

Answer 8

1. Vascular
2. Neurogenic
3. Hormonal
4. Iatrogenic

Question 9

Obstructive sleep apnea

Answer 9

1. Hypoxia --> high cortisol and catacholamines -->
Insulin resistance + metabolic syndrome
2. SNoring, apnea
3. Fatigue daytime somnolence
4. ED: decreased NO in cavernosal muscle

T worsens untreated OSA
TX: CPAP, lifestyle intervention

Question 10

Different causes of Pituitary hypogonadism
- Low LH + FSH
Low T

Answer 10

1. Prolactinoma: increases Prl
2. Tumors/Mass effects
   - craniopharyngioma
   - pituitary tumor
   - mets
3. Infiltrative disorders: hemachromatosis (iron deposits selectively in gonadotropes)
4. Inflammatory: lymphocytic hypophysitis due to new drug IPI when treating melanoma

Question 11

Loss of inhibin

Answer 11

FSH > LH

• inhibin regulates FSH
• FSH + LH are usually the same at ~10-12

Question 12

First sign of puberty in boy

Answer 12

testicular enlargement

Question 13

Pathophys of T deficiency: testicular dysfxn

Answer 13

see slide

Question 14

Hypergonadotropic hypogonadism

high FSH
high/low LH
Low T

• Different congenital causes

Answer 14

1. Congenital: anorchia, vanishing testes syndrome
   - high GnRH is induced to try to stimulate failing gonad
2. Klinefelter’s syndrome
   - failing testes
   - no sertoli, intact leydig
   - low inhibin B lvls
   - delayed puberty
   - genecomastia
   - risk for DVT/PE

Question 15

Causes of acquired hypergonadotropic hypogonadism

high FSH
high/low LH
Low T

Answer 15

1. Trauma or torsion
   - testes dies –> sertoli dies –> loss of inhibin –> rise in FSH
2. Mumps orchitis
3. Alcohol: direct testicular toxin
4. Diabetes
5. Radiation/chemotherapy
6. Autoimmune testicular failure: check TSH, glucose, B12, Vit D
7. *Pituitary tumor:
   - High FSH:LH, low T

Question 16

Gonadotrope pituitary tumor

:aka FSH/LH secreting tumor

Answer 16

glycoprotein tumor of the pituitary that overproduces abnl LH + FSH, while at the same time compresses the pituitary and prevent release of real LH+FSH –> T lvls end up low

Labs: high FSH/LH, low T

Hx: HA, lateral visual disturbances, ED

Exam: visual fields, sx of hypogonadism, softening of testes

Tx: surgery

Question 17

What should we do in pts with low-nl T lvls?

Answer 17

1. diet
2. lifestyle
3. successful weight loss
   - increase T lvls
   - Improve OSA
   - Improve cardiovascular and metabolic fitness
   - Improve ED

DO NOt dz hypogonadism right away

Question 18

Cardiac Risks of T therapy

Answer 18

Increased cardiac events

• esp in elderly men
• ACS, MI, Syncope, HTN, arrhythmia, edema, CHF

*Too low or Too high T has adverse effects

Question 19

Potential risk of T therapy

Answer 19

1. Stim prostate growth in previously undiagnosed prostate cancer
2. risk of bladder outlet symptoms due to increase in prostate volume
3. Edema in pts with pre-existing cardiac, renal, hepatic disease
4. Gynecomastia (converted to E)
5. Erythrocytosis
6. PPT / worsening of sleep apnea
7. increased CV risk

Question 20

Things that can cause hypogonadotropic hypogonadism: Low GnRH, LH, FSH, T

Answer 20

1. genetic - rare
   - Kallman syndrome
2. Acquired:
   - narcs, GC, hemochromatosis, tumor, XRT, stress, illness

Question 21

Things that can cause high FSH, LH, low testosterone

Answer 21

1. Primary testicular failure

2. Gonadotrope pituitary tumor

Question 22

DHT acts specifically on what?

Answer 22

External genitalia and prostate

Question 23

what is the gonadal peptide that inhibits FSH in males and acts locally in the testes?

Answer 23

Inhibin B (alpha and betaB)
- not betaA

Question 24

Hypogonadotropic hypogonadism can be due to:

Answer 24

1. Congenital
   - GnRH neurons fails to migrate to hypothalamus (Kallman’s syndrome if anosmia is also included)
   - neurons migrate with olfactory neurons in utero
   (579)

• intact hardware, but software program is missing
  2. Acquired deficits of GnRH or LH and FSH

Question 25

Prolactinomas

Answer 25

Most common pituitary tumor - Makes Prl which blocks GnRH induced LH and FSH signal - Acquired cause of Hypogonadotropic hypogonadism