Hypogonadism (male and female) Flashcards
What is female hypogonadism?
Characterised by impairment of ovarian function
What is the aetiology of female hypogonadism?
Primary hypogonadism (hypergonadotrophic) - Gonadal dysgenesis: Chromosomal abnormalities (e.g. Turner’s syndrome), FMR1 gene pre-mutation carriers (CGG repeats between 55&200) - Gonadal damage: Autoimmune, iatrogenic (chemotherapy, radiation, surgery) - Secondary hypogonadism (hypogonadotrophic) - Functional: Stress, weight loss, excessive exercise, eating disorders (anorexia nervosa, bulimia) - Pituitary/hypothalamic tumours and infiltrative lesions: Pituitary adenomas, craniopharyngiomas, haemochromatosis - Hyperprolactinaemia: Prolactinomas or tumours causing pituitary stalk compression - Congenital GnRH deficiency: Kallmann’s syndrome, idiopathic
What is the epidemiology of female hypogonadism?
Symptoms of oestrogen deficiency - Night sweats, hot flush, vaginal dryness and dyspareunia - Reduced libido, infertility - Symptoms of underlying cause
What are the signs of female hypogonadism on examination?
Pre-pubertal hypogonadism: - Delayed puberty (primary amenorrhoea, absent breast development, no secondary sexual characteristics) - Eunuchoid proportions (e.g. long legs, increased arm span for height) Post-pubertal hypogonadism: - Regression of secondary sexual characteristics (loss of secondary sexual hair, breast atrophy). Perioral and periorbital fine facial wrinkles - Signs of underlying cause/ associated symptoms - Hypothalamic/pituitary disease: Visual field defects - Kallmann’s syndrome: Anosmia - Turner’s syndrome: Short stature, low posterior hairline, high arches palate, widely spaced nipples, wide carrying angle, short fourth and fifth metacarpals, congenital lymphoedema - Patient’s with autoimmune primary ovarian failure: Signs of autoimmune disease e.g. hyperpigmentation in Addison’s disease or vitiligo
What are the investigations for female hypogonadism?
- Reduced serum oestradiol. Serum FSH & LH: Raised in primary (due to decreased feedback inhibition by ovarian oestradiol and inhibin). Reduced or inappropriately normal FSH/LH in secondary hypogonadism - Investigation to determine the aetiology - Primary: Karyotype (to look for chromosomal abnormalities: complete or partial deletion of the X chromosome in Turner’s syndrome or presence of Y chromsome. Pelvic imagine: in pts with primary amenorrhoea, to demonstrate presence or absence of uterus and vagina and vaginal or cervical outlet obstruction (Mullerian agenesis, androgen insensitivity, transverse vaginal septum, imperforate hymen - In unexplained pre-mature ovarian failure: screening for pre-mutation in FMR1 gene after appropriate genetic counselling and informed consent - Secondary: Pituitary function tests (9am cortisol, TFTs, prolactin), visual field testing, hypothalamic-pituitary MRI, smell tests for anosmia. Serum transferrin saturation if hereditary haemochromatosis is suspected - Turner’s: Periodic echo and cardio follow-up. Renal USS - Autoimmune oophoritis: Evaluate for autoimmune adrenal insufficiency
What is male hypogonadism?
A syndrome of reduced testosterone production, sperm production or both
What is the aetiology of primary male hypogonadism?
- Gonadal dysgensis: Klinefelter’s syndrome (XXY), undescended testes (cryptochidism) - Gonadal damage: Infection (e.g. mumps), torsion, trauma, autoimmune, iatrogenic (chemotherapy, surgery, radiation) - Rare causes: Defects in enzymes involved in testosterone synthesis, myotonic dystrophy
What is the aetiology of secondary male hypogonadism?
- Pituitary/hypothalamic lesions - GnRH deficiency: Kallmann’s syndrome (associated with anosmia), idiopathic - Hyperprolactinaemia - Systemic/chronic diseases - Rare causes: Genetic mutation. Secondary hypogonadism may be seen in a number of are syndromes - Prader-Willi syndrome: Loss of critical region on chromosome 15 causing obesity and short stature, small hands, almond-shaped eyes, learning difficulty/postnatal hypotonia - Laurence-Moon-Biedl syndrome: Obesity, polydactyly, retinitis pigmentosa, learning difficulty
What is the epidemiology of male hypogonadism?
- Primary accounts for 30-40% of male infertility, secondary accounts for 1-2% - Most common cause of primary hypogonadism is Klinefelter’s syndrome
What are the presenting symptoms of male hypogonadism?
- Delayed puberty ( f the onset is before puberty) - Reduced libido, impotence, infertility - Symptoms of underlying cause e.g. Klinefelter’s syndrome: intellectual dysfunction and behavioural abnormalities which cause difficulty in social interactins
What are the signs of male hypogonadism on examination?
- Measure testicular volume using Prader’s orchidometer (ellipsoids of different sizes) Normal adult testicular volume: 15-25 ml Pre-pubertal hypogonadism: - Signs of delayed puberty (high pitched voice, reduced pubic/axillary/facial hair, small or undescended testes, small phallus), gynaecomastia, eunuchoid proportions, arm span more than height, lower segment larger than upper segment ( delayed fusion of epiphyses and continued growth of bones) - Features of underlying cause e.g. cryptochidism, anosmia in Kallmann’s Postpubertal hypogonadism: - Reduced pubic/axillar/facial hair, soft and small tests, gynaecomastia, fine perioral wrinkles. Features of the underlying cause e.g. visual field defects due to pituitary tumour, signs of systemic chronic illness
What are the investigations for male hypogonadism?
- Serum total testosterone, SHB and albumin, LH & FSH - Primary: Reduced testosterone, raised LH and FSH (neg feedback) - Secondary: Reduced testosterone, reduced or inappropriately normal LH/FSH Determine level of defect: - Primary: karyotype (exclude Klinefelter’s) - Secondary: Pituitary function tests, MRI of hypothalamic pituitary area, visual field testing, smell tests for anosmia. Iron studies if hereditary haemochromatosis suspected - Bone age: In boys with delayed puberty: determined by comparison of radiograph of patient’s bones in left hand and wrist with bones of a standard atlas (allows assessment of skeletal maturation and potential for future skeletal growth
