Endocrine Regulation of Male fertility Flashcards
What is the most common cause of delayed puberty?
Constitutional delay (late bloomers). It is confirmed with hand/wrist X-ray to confirm bone age which will be delayed in constitutional delay
What is testosterone produced by and what are its functions?
|It is produced by Leydig cells. Its functions depends on the age of the person. It is involved in:
- Growth,
- Skeletal muscles,
- Epiphyseal plates,
- Larynx growth,
- Secondary sex characteristics
- Erythropoiesis and behavior
- In adults it is involved in muscle mass, mood, bone mass, libido, body shape, erectile function and spermatogenesis
What are the cells of the testes?
- Leydig cells which secrete testosterone to promote sperm development.
Sertoli cells which make up the blood testes barrier, remove damaged spermatocytes and secrete androgen binding hormone
What are the clinical features of hypogonadism in children and adults
Children - Slow growth in teens, no pubertal growth spurt, lack of secondary sexual development.
Adults - Low mood, poor libido, erectile dysfunction, hot flushes/sweats, poor muscle bulk, poor energy, sparse body/facial hair, gynaecomastia, gynoid weight gain, short phallus/reduced testicular volume and low trauma fractures
What are the tests for suspected hypogonadism?
- Bloods: Early morning, fasting testosterone. Free testosterone (>200), total testosterone (>10) and SHBG.
- Do LH and FSH to determine if pituitary or testicular cause
- Others depend on testicular or pituitary pathology so can do: Semen analysis, pituitary screen/MRI, karyotyping, testicular ultrasound
What are the blood results/name of disorder if hypogonadism is due to pituitary or testicular cause
Pituitary - Hypogonadotropic hypogonadism . So there will be low LH/FSH and low testosterone.
Testicular - Hypergonadotrophic hypogonadism. High LH/FSH but low testosterone
What are some causes of hypogonadotrophic hypogonadism?
- Pituitary disease (prolactinoma),
- Head injury,
- Kallmann’s
- Functional hypothalamic hypogonadism (caused by excessive exercise, weight change, physical or psychological stress or systemic illness)
What is Kallmann’s syndrome?
- Failure of GnRH cells to migrate to hypothalamus. It is associated with aplasia/hypoplasia of olfactory lobes, causing anosmia/hyposmia.
May also be associated with deafness, renal agenesis and cleft lip/palate
What is the diagnosis and underlying genetics of Kallmann’s syndrome
- Anosmia in 75%. There will be low testosterone and low FSH/LH but the rest of the pituitary function is normal. May have absent olfactory bulb.
- Can be X-linked (KAL1), autosomal dominant (KAL2) or autosomal recessive (KAL3)
What are some causes of primary gonadal disease?
- Chromosomal defects eg, Kleinfelters.
- Seminiferous tubule or Leydig cell failure. May occur following trauma, chemo.
- Cryptorchidism
What is Klinefelter’s syndrome
- Extra X chromosome so the karyotype is 47 XXY (+/- mosaicism)
- It is a hypergonadotrophic hypogonadism as seminiferous tubules regress and Leydig cells do not function.
What is the presentation and treatment of Klinefelter’s syndrome?
- Delayed puberty, reduced testicular volumes, reduced secondary male sexual characteristics, persistent gynaecomastia, azospermia, behavioral issues.
- Treat with androgen replacement (IM or topical), psychological support and fertility counselling (hCG, recombinant LH/FSH and GnRH pumps).
What are the side effects of testosterone replacement therapy?
- Mood issues (aggression),
- Libido issues,
- Increased haematocrit/polycythaemia
- Lower UT symptoms,
- Acne,
- Gynaecomastia
What are the symptoms of hypotesteronism
Lethargy,
Weakness,
Weight gain,
Loss of libido
Erectile dysfunction
Gynaecomastia
Depression
What is Kleinfelter’s syndrome
Chromosomal abnormality were the male has an extra X chromosome
