Card Set Information
Has effects on the tubules of the testes to form sperm
Has effects on Leydig cells which form testosterone & nourish the sperm.
Which tests do you order to diagnose male hypogonadism?
TOTAL and BIOAVAILABLE (bound - not as accurate), free if necessary. (I think) Also get an LH level, FSH level and prolactin (elavated prolactin performs negative feedback on GnRH)
Primary hypogonadism lab values
High-normal to High LH and FSH
(Problem is with testes not producing)
Secondary hypogonadism lab values
Normal to low LH and FSH
(problem is in the pituitary or hypothalamus)
Primary hypogonadism causes
Klinefelter's syndrome & other (mostly congenital) issues
Drugs, radiation, mumps, chronic disease (HIV, etc.)
Male hypogonadism that results in deficient secondary sex-characteristics (high-pitched voice, lack of hair growth, arm span > high by 5 cm and long legs with shorter torso.
Male with extra X-chromosome
Low amounts of inhibin are produced in testes so it doesn't feed back appropriately & leads to increased levels of LH and FSH with low testosterone & high estradiol
Tall, breast development, small testes, slightly feminized physique w/ mildly impaired IQ.
Diagnose with buccal smear-looking for barr bodies
No trx. listed - testosterone after puberty?
Secondary hypogonadism causes
Kallman's syndrome (lack of smell)
Idiopathic hypogonadotropic hypogonadism w/ retardation
Abnormal beta-subunit of LH or FSH
Sarcoidosis, drugs, alcohol, etc.
Tests for hypogonadism
Serum testosterone - 8:00 am
Serum FSH & LH w/ prolactin
Peripheral leukocyte karyotype (Klinefelter's)
Testosterone replacement (not for people w/ potential reversibility because you can suppress their ability to make their own testosterone)
Treat underlying disease
Measuring injectable steroids
Measure midway between injections
Measure gel steroid levels
After one month
Measure oral steroids
After administering 3-5 hours
Rise with androgen therapy but should remain within the reference range. Maximal increase in prostate volume occurs 3 mos after initiation of trx.
Seen most commonly with injectable steroids
Alkylated oral testosterone can cause this. Measure LFTs when administering oral therapy
Should see within 3-6 months
Can be caused by low testosterone but is more likely due to another problem. Can give a phosphodiesterase inhibitor (Viagra) for that.
For secondary hypogonadism only
GnRH pulsatile infusion
hCG- stimulates the Leydig cells to produce testosterone (necessary for sperm production)
hMG - stimulates the seminiferous tubules to produce sperm