L19 - Hypogonadism Flashcards
role of seminiferous tubules
where inhibin and anti mullerian hormone are made by sertoli cells and sperm produced
leydig cells ?
produce androgens
Testosterone action
regulates gonadotropin secretion by HP system
intiation and maintenance of spermatogenesis
formation of the male phenotype during embryogenesis
promotion of sexual maturation at puberty and its maintenance thereafter
increase in lean body mass and decrease in fat mass
What is male hypogonadism ?
Decrease in one or both of the two major functions of the testes: sperm production or testosterone production.
Disease of the testes (primary hypogonadism) or disease of the hypothalamus or pituitary (secondary hypogonadism)
Primary hypogonadism: Testosterone below normal and the serum LHand/orFSH are above normal.
Secondary hypogonadism: Testosterone below normal and the serum LHand/orFSH are normal or low.
Causes of primary hypogonadism
Klinefelter syndrome Cryptorchidism Infection-mump Radiation Trauma Torsion Idiopathic
causes of secondary hypogonadism ?
Congenital GnRH deficiency Hyperprolactinemia GnRH analog Androgen Opioids Illness Anorexia nervosa Pituitary disorder
Clinical features of hypogonadism
First trimester – female genitalia to ambiguous genitalia to partial virilization
Third trimester – micropenis
Prepubertal – failure to undergo or complete puberty
Adults
Signs and symptoms of hypogonadism
incomplete sexual development reduced sexual desire reduced body hair reduced height reduced muscle bulk inability to father children due to low sperm count
less specific symptoms : reduced energy/motivation reduced aggressiveness poor concentration and memory increased body fat
Conditions with a High Prevalence of hypogonadism (Screening Suggested)
HIV-associated weight loss ESRD and maintenance hemodialysis Moderate to severe COPD Osteoporosis or low trauma fracture (esp if young) Type 2 diabetes mellitus Infertility
relevant medical history
Puberty and sexual development Past/present major illnesses Past/present nutritional deficiency All prescription & nonprescription drugs Relationship problems Sexual problems Major life events Related family history Recent changes in body (breasts) Testicle problems eating disorders excessive exercise
examination for hypogonadism
Amount of body hair Breast exam for enlargement/tenderness Size and consistency of testicles Size of the penis Signs of severe & prolonged hypogonadism Loss of body hair Reduced muscle bulk and strength Osteoporosis Smaller testicles Arm span
Investigations for hypogonadism ?
Serum testosterone LH/FSH SHBG LFT Semen analysis Karoyotyping Pituitary function testing MRI DEXA scan
guidelines on screening
Initial screen = morning total testosterone
Levels are highest in the morning
Normal testosterone is generally age dependent
Confirmation = repeat morning total testosteron
Free or bioavailable
Do not screen during acute or subacute illness
Illness, malnutrition, and certain medications may temporarily lower testosterone
Testosterone circulates mostly bound to SHBG, what lowers SHBG?
Moderate obesity Nephrotic syndrome Hypothyroidism Use of Glucocorticoids Progestins Androgenic steroids
What raises SHBG ?
What raises SHBG Aging Hepatic cirrhosis Hyperthyroidism Anticonvulsants Estrogens HIV infection
