hypogonadism Flashcards
Define hypogonadism in females?
characterised by impairement of ovarian function
outline the aetiology of primary hypogonadism in females?
gonadal dysgenesis- > due to chromosomal abnormalities-> turner’s
gonadal damage-> autoimmune, chemotherapy, radiotherapy
outline the aetiology of secondary hypogonadism in women?
Functional (e.g. stress, weight loss, excessive exercise, eating disorders)
Pituitary/Hypothalamic Tumours and Infiltrative Lesions (e.g. pituitary adenomas, haemochromatosis)
Hyperprolactinaemia (e.g. due to prolactinoma)
Congenital GnRH deficiency: Kallmann’s syndrome, idiopathic
summarise the epidemiology of hypogonadism?
Secondary hypogonadism is a more common cause of anovulation/amenorrhoea
Turner’s syndrome occurs in around 1.5% of conceptions
what are the symptoms of hypogonadim in women?
Symptoms of oestrogen deficiency:
- Night sweats
- Hot flushing
- Vaginal dryness
- Dyspareunia
- Decreased libido
- Infertility
Symptoms of the underlying cause
what are the signs of turner’s syndrome?
Short statue
Low posterior hair line
High arched palate
Widely spaced nipples
Wide carrying angle
Short fourth and fifth metacarpals
Congenital lymphoedema
what are the signs of hypogonadism in women?
PRE-Pubertal Hypogonadism
- Delayed puberty (primary amenorrhoea, absent breast development, no secondary sexual characteristics)
- Eunuchoid (long legs, arm span greater than height)
POST-Pubertal Hypogonadism
- Regression of secondary sexual characteristics (e.g. loss of secondary sexual hair, breast atrophy)
- Perioral and periorbital fine facial wrinkles
Signs of underlying cause
- Hypothalamic/Pituitary disease - visual field defects
- Kallmann’s syndrome - anosmia
- Turner’s syndrome
Autoimmune primary ovarian failure - there may be signs of other autoimmune diseases (e.g. vitiligo)
what is a sign of Kallman’s syndrome?
anosmia
what is serum LH and FSH in primary and secondary hypogondism in women?
Primary hypogonadism = HIGH
Secondary hypogonadism = LOW
what are the key investigations for hypogonadism in a woman?
Low serum oestradiol
Serum FSH/LH
- Primary hypogonadism = HIGH
- Secondary hypogonadism = LOW
what are the investigations for primary hypogonadism in women?
Karyotype (look for chromosomal abnormalities)
Pelvic imaging (US or MRI) - performed in primary amenorrhoea to check for structural defects (e.g. androgen insensitivity)
what are the investigations for secondary hypogonadism in women?
Pituitary function tests (e.g. 9 am cortisol, TFTs, prolactin)
Visual field testing
Hypothalamic-pituitary MRI
Smell tests for anosmia
Serum transferrin saturation (check for haemochromatosis)
Define hypogonadism in males?
A syndrome of decreased testosterone production, sperm production or both
outline the aetiology of primary hypogonadism in males?
Gonadal dysgenesis (e.g. Klinefelter’s syndrome, undescended testicles)
Gonadal damage (e.g. infection, torsion, trauma, autoimmune, iatrogenic)
Drugs: alkylating agents, such as cyclophosphamide and chlorambucil-> Affect testosterone pri
Rare causes (e.g. defects in enzymes involved in testosterone synthesis)
what are the causes of secondary hypogonadism in males?
Pituitary/Hypothalamic lesions
GnRH deficiency (Kallmann’s syndrome)
Hyperprolactinaemia
Systemic/chronic diseases->diabetes, HTN
High dose glucocorticoids->
Prader-Willi syndrome (short, small hands, almond-shaped eyes, learning difficulty, postnatal hypotonia)
Laurence-Moon-Biedl syndrome (obesity, polydactyly, retinitis pigmentosa, learning difficulty)
what are the riskf factors for hypogonadism in men?
genetic -> Klinfelters syndrome
type 2 diabetes
use of alkylating agents, glucucorticoids, opiods
use of exogenous sex hormones and GnRH analogues
hyperprolactinaemia
pituitary tumour or apoplexy-> Causes compression of gonadotrophs (basophilic cells of the anterior pituitary specialised to secrete FSH or LH), resulting in secondary hypogonadism.
Severe systemic illness-> suppress the hypothalamic-pituitary-gonadal axis, resulting in decreased GnRH secretion and secondary hypogonadism
testicular damage-> torsion, direct trauma, irradiation
summarise the epidemiology of hypogonadism in men?
Primary hypogonadism accounts for 30-40% of male infertility
- Most common cause: Klinefelter’s Syndrome (XXY)
Secondary hypogonadism accounts for 1-2%
what are the features of a patient with Klinefelter syndrome?
what are the symptoms of hypogonadism in men?
Delayed puberty
Decreased libido
Impotence
Erectile dysfunction
Infertility
Symptoms of underlying cause (e.g. Klinefelters –> intellectual dysfunction, behavioural abnormalities)
what are the signs of hypogonadism on physical examination in men?
Measure testicular volume using Prader’s orchidometer (normal adult volume = 15-25 mL)
Prepubertal Hypogonadism
1) Signs of delayed puberty
- High pitched voice
- Decreased pubic/axillary/facial hair
- Small or undescended testicles
- Small penis
2) Gynaecomastia
3) Eunuchoid proportions (arm span > height)
4) Features of underlying cause (e.g. undescended testicle, anosmia in Kallmann’s syndrome)
Postpubertal Hypogonadism
- Decreased pubic/axillary/facial hair
- Soft and small eyes
- Gynaecomastia
- Fine perioral wrinkles
- Features of underlying cause (e.g. visual defects if pituitary cause)
whata are the appopriate investigations for hypogonadism in men?
Serum total testosterone
Sex hormone binding globulin (SHBG) - check that this is not the reason there is low free testosterone
LH and FSH
what are testosterone, LF and FSH levels in primary and secondary hypogonadism in males>
Primary Hypogonadism:
- Low testosterone
- High LH and FSH
Secondary Hypogonadism:
- Low testosterone
- Inappropriately normal/low LH and FSH
what other investigation should you consider for hypogonadism in males?
Assess bone age (risk of fracture)
what additional investigations would you order to investigate primary hypogonadism in males?
karyotyping (check for Klinefelter’s syndrome)
what additional investigations would you order to investigate secondary hypogonadism in males?
Pituitary function tests
MRI of the hypothalamic/pituitary area
Visual field testing
Smell testing (for anosmia)
Iron testing (for hereditary haemochromatosis)
