Male Pathophys Flashcards
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
Sexual signs of hypogonadism
- diminished libido
- erectile dysfxn
- DIff achieving orgasm
- decreased performance
*but can present this way even if indiv doesnt have hypogonadism
CLue for exogenous androgen exposure
undetectable gonadotropins
Pathophys of testosterone deficiency: hypothalamic dysfxn
see slide
Genetic causes of GnRH deficiency
Kallman syndrome
Mut in KAL1 at pituitary
- Presents with Anosmia: can’t smell
Acquired Central Hypogonadism
Low - low nl LH + FSH
Low T
- GnRH pulse generator defect due to:
- stress
- severe illness
- abnl weight loss - Narcotics:
- opioids/marijuana: wipe out pulse generator - Glucocorticoids:
- steroid injxn: suppresses adrenal axis and T - Supplements:
- prohormones
- anabolic steroids: cause undetectable LH/FSH
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
Causes of ED
- Vascular
- Neurogenic
- Hormonal
- Iatrogenic
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
Different causes of Pituitary hypogonadism
- Low LH + FSH
Low T
- Prolactinoma: increases Prl
- Tumors/Mass effects
- craniopharyngioma
- pituitary tumor
- mets - Infiltrative disorders: hemachromatosis (iron deposits selectively in gonadotropes)
- Inflammatory: lymphocytic hypophysitis due to new drug IPI when treating melanoma
Loss of inhibin
FSH > LH
- inhibin regulates FSH
- FSH + LH are usually the same at ~10-12
First sign of puberty in boy
testicular enlargement
Pathophys of T deficiency: testicular dysfxn
see slide
Hypergonadotropic hypogonadism
high FSH
high/low LH
Low T
- Different congenital causes
- Congenital: anorchia, vanishing testes syndrome
- high GnRH is induced to try to stimulate failing gonad - Klinefelter’s syndrome
- failing testes
- no sertoli, intact leydig
- low inhibin B lvls
- delayed puberty
- genecomastia
- risk for DVT/PE
Causes of acquired hypergonadotropic hypogonadism
high FSH
high/low LH
Low T
- Trauma or torsion
- testes dies –> sertoli dies –> loss of inhibin –> rise in FSH - Mumps orchitis
- Alcohol: direct testicular toxin
- Diabetes
- Radiation/chemotherapy
- Autoimmune testicular failure: check TSH, glucose, B12, Vit D
- *Pituitary tumor:
- High FSH:LH, low T
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
What should we do in pts with low-nl T lvls?
- diet
- lifestyle
- successful weight loss
- increase T lvls
- Improve OSA
- Improve cardiovascular and metabolic fitness
- Improve ED
DO NOt dz hypogonadism right away
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
Potential risk of T therapy
- Stim prostate growth in previously undiagnosed prostate cancer
- risk of bladder outlet symptoms due to increase in prostate volume
- Edema in pts with pre-existing cardiac, renal, hepatic disease
- Gynecomastia (converted to E)
- Erythrocytosis
- PPT / worsening of sleep apnea
- increased CV risk
Things that can cause hypogonadotropic hypogonadism: Low GnRH, LH, FSH, T
- genetic - rare
- Kallman syndrome - Acquired:
- narcs, GC, hemochromatosis, tumor, XRT, stress, illness
Things that can cause high FSH, LH, low testosterone
- Primary testicular failure
2. Gonadotrope pituitary tumor
DHT acts specifically on what?
External genitalia and prostate
what is the gonadal peptide that inhibits FSH in males and acts locally in the testes?
Inhibin B (alpha and betaB) - not betaA
Hypogonadotropic hypogonadism can be due to:
- 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
