Flashcards in Male Pathophys Deck (25):
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Hypogonadism
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
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Sexual signs of hypogonadism
1. diminished libido
2. erectile dysfxn
3. DIff achieving orgasm
4. decreased performance
*but can present this way even if indiv doesnt have hypogonadism
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CLue for exogenous androgen exposure
undetectable gonadotropins
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Pathophys of testosterone deficiency: hypothalamic dysfxn
see slide
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Genetic causes of GnRH deficiency
Kallman syndrome
Mut in KAL1 at pituitary
- Presents with Anosmia: can't smell
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Acquired Central Hypogonadism
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
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nl T lvls for adult
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
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Causes of ED
1. Vascular
2. Neurogenic
3. Hormonal
4. Iatrogenic
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Obstructive sleep apnea
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
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Different causes of Pituitary hypogonadism
- Low LH + FSH
Low T
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
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Loss of inhibin
FSH > LH
*inhibin regulates FSH
- FSH + LH are usually the same at ~10-12
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First sign of puberty in boy
testicular enlargement
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Pathophys of T deficiency: testicular dysfxn
see slide
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Hypergonadotropic hypogonadism
high FSH
high/low LH
Low T
- Different congenital causes
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
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Causes of acquired hypergonadotropic hypogonadism
high FSH
high/low LH
Low T
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
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Gonadotrope pituitary tumor
:aka FSH/LH secreting tumor
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
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What should we do in pts with low-nl T lvls?
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
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Cardiac Risks of T therapy
Increased cardiac events
- esp in elderly men
- ACS, MI, Syncope, HTN, arrhythmia, edema, CHF
*Too low or Too high T has adverse effects
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Potential risk of T therapy
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
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Things that can cause hypogonadotropic hypogonadism: Low GnRH, LH, FSH, T
1. genetic - rare
- Kallman syndrome
2. Acquired:
- narcs, GC, hemochromatosis, tumor, XRT, stress, illness
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Things that can cause high FSH, LH, low testosterone
1. Primary testicular failure
2. Gonadotrope pituitary tumor
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DHT acts specifically on what?
External genitalia and prostate
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what is the gonadal peptide that inhibits FSH in males and acts locally in the testes?
Inhibin B (alpha and betaB)
- not betaA
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Hypogonadotropic hypogonadism can be due to:
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
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