Hypogonadism Flashcards
Define Hypogonadism
Clinical syndrome that comprises symptoms and/or sign + biochemical evidence of testosterone or oestradiol deficiency
Define the following in females: Primary hyogonadism Secondary hypogonadism Amenorrhoea Oligomenorrhoea
Primary hyogonadism: Defect in the ovaries → low oestradiol → less -ve feedback → High GnRH → High LH /FSH
Secondary hypogonadism:
Hypothalamic dysfunction → Reduced LH/FSH production → Reduced oestradiol → less negative feedback
Amenorrhoea: absence of periods (primary = failure to begin by 16, secondary = absence for 3 months)
Oligomenorrhoea: irregular, long, cycles
Define the following in males:
Primary hyogonadism
Secondary hypogonadism
Primary hyogonadism: defect at the level of testes - testicular failure
Associated with low testosterone and elevated gonadotrophins
Secondary hypogonadism:
Defect at the level of the hypothalamic-pituitary axis
Associated with low testosterone and low (or inappropriately normal) gonadotrophins
Aetiology of Hypogonadism in females
Primary: Premature ovarian insufficiency Autoimmune Iatrogenic (ovariectomy, chemo) Turner's syndrome (lacking 1 X chromosome)
Secondary:
Pregnancy and lactation (most common cause of secondary)
Kallman’s syndrome
Low BMI, stress, weight loss, eating disorder, excessive exercise
Post-pill amenorrhoea
Hyperprolactinaemia
Androgen excess (gonadal tumour, PCOS)
Aetiology of Hypogonadism in males
Primary: Klinefelter syndrome (47XXY) Noonan syndrome Cryptorchidism Infections (mumps -> orchitis) Drugs (cyclophosphamide + chlorambucil) Testicular trauma, torsion, irradiation Auto-immune orchitis
Seconadry: Hyperprolactinaemia Combined pituitary hormone deficiency Isolated hypogonadotrophic hypogonadism Pituitary tumours Parasellar tumours Empty/partial empty sella syndrome Durgs e.g. opioids, glucocorticoids, GnRH analogues Irradiation Head injury, trauma, surgery
Symptoms of Hypogonadism in males and females
Males: Decreased libido Loss of spontaneous morning erections + erectile dysfunction Gynaecomastia Infertility Decreased energy and fatigue
Females: Amenorrhoea/oligmenorrhoea Night sweats, hot flush Vaginal dryness, dyspareunia Reduced libido Infertility (oestrogen deficiency) Pre-pubertal: absent breast development, no secondary sexual characteristics Post-pubertal: Loss of sexual hair, breast atrophy
Signs of Hypogonadism in men and women
Men: Gynaecomastia Bitemporal hemianopia Delayed puberty Decreased muscle mass and strength Lack of hair
Women:
Vaginal dryness
Pre-pubertal: absent breast development, no secondary sexual characteristics
Investigations for Hypogonadism in men
Serum total testosterone: Reduced (<10.4)
Semen analysis: low sperm count if infertile
Serum SHBG: increased or decreased
Serum LH/FSH: Elevated (primary) or decreased/normal (secondary)
Serum free testosterone: reduced (<0.2)
Serum bioavailable testosterone: reduced (<2.4)
Serum prolactin: elevated (>7.83)
Iron studies: rule out haemochromatosis
MRI pituitary: may reveal pituitary adenoma or empty sella
Genetic testing: Klinefelter’s
Investigations for Hypogonadism in women
Pregnancy test: negative
Oestradiol: reduced
FSH/LH: elevated (primary), reduced (secondary)
Day 21 progesterone: increase if ovulation
Prolactin: raised
TFTs: raised
Androgens: ?PCOS
Chromosomal analysis: ?Turner’s
USS scan ovaries/uterus: ?PCOS