Male hypogonadism Flashcards
primary- when the loose the target gland, secondary when the pituitary doesnt work
Kline felter syndrome
47 XXY Seminiferous Tubule dysgenesis
Most common genetic cause of male hypogonadism (1/600 males)
The XXY genotype is usually due to meiotic nondisjunction during parental gametogenesis: egg with 2 X chromosomes or a sperm with an X and a Y chromosomes, after fertilization, non disjunction during mitotic division typically results in mosaicism
Loss of negative feedbaks, increased LH concentration , stimulate estrogen precursor production from the abnormal leydig cells, feminization and gynecomastia
Klinefelter syndrome - expressed during puberty
As the gonadotropins increase during puberty, seminiferous tubules do not enlarge; they undergo fibrosis and hyalinization, small firm testes
Obliteration of the seminferous tubules result in azospermia, leydic cells are functionally abnormal (Low T)
Klinefelter syndrome clinical appearance
long bone abnormality of leg aindependent of that related to testosterone deficiency, psychosocial abnormality involving social interactions- poor insight/judgement
Impairment of higher level linguistic competence, but sparing vocabulary and understanding of language, attention deficit with resultant impulsiveness
Pulm, cancer, varicose veins, SLE, diabetes
Male hypogonadism
Screen those with signs and symptoms or clinical disorders associated with the disease
Primary0 low T and/or low sperm, with high LH and FSH, consider karryotype for klinefelters syndrome
Secondary- low testosterone and/or sperm with low or inappropriatly not increased LH and FSH needs pituitary work up
Treat or address underlying cause and associated condition, treatment options numerous based on patient goals and preferences, screen for condraindications to therapy and regularly monitor for adverse events
Primary causes of male hyogonadism
Primary (serum testosterone is low, FSH and LH is really high)
Congenital- testicular agenesis, Klinefelter’s syndrome (47XXY), 5a-reductase and other enzyme defects, untreated cryptorchidism
Acquired- bilateral orchitis (mumps), Bilateral testicular tosion, irradiation, cytotoxic drugs, bilateral varicocele
Secondary Causes of male hypogonadism
(Serum testosterone low, FSH and LH are normal or low
Pituitary disorders- tumors (especially if causing hyperprolactinaemia), panhypopituitarism, Hypothalamic disorders (Kallmans syndrome- GnRH neurons dont migrate from olfactory bulb), opioid therapy/abuse
Effects of Testosterone and its metabolites in men
DHT- Facial and body hair, acne, scalp hair loss, prostate growth
Testossterone–> muscle mass, skeletal grwoth, spermtogenesis, sexual function
Estradiol (E2)–> bone formation and breast tissue
Testosterone has a circadian rythm
Binding of T to plasma proteins
T travels with SHBG, and labumin and free bioactive is free + albumin bound
morning is high
Afternoon can be normally low
