Hypogonadism Flashcards
Define hypogonadism
Males: testosterone deficiency and/or reduced sperm production
Females: Premature ovarian failure – cessation of menses for > 1 year before the age of 40
due to loss of ovarian function
What are the causes/risk factors of hypogonadism?
Males Primary – gonadal failure • Klinefelter’s syndrome XXY (most common cause) • Cryptorchidism • Infection e.g. mumps • Testicular torsion • Trauma • Autoimmune • Iatrogenic (chemo/radiotherapy, surgery) Secondary – pituitary/hypothalamic failure • Pituitary tumours • Head injury • Kallman’s syndrome (GnRH deficiency) • Prolactinoma/hyperprolactinaemia • Prader-Willi syndrome
Females Primary – gonadal failure • Turner’s syndrome • Autoimmune • Iatrogenic (chemo/radiotherapy, surgery) Secondary – pituitary/hypothalamic failure • Functional - Stress - Weight loss - Excessive exercise - Eating disorders • Pituitary/hypothalamic - Pituitary adenoma - Craniopharyngioma - Haemochromatosis - Prolactinoma/hyperprolact inaemia - Kallman’s syndrome (GnRH deficiency)
What are the symptoms of hypogonadism?
Males • Reduced libido • Erectile dysfunction • Impotence • Infertility
Females • Night sweats • Sleep disturbance • Amenorrhea • Hot flushes • Vaginal dryness • Dyspareunia • Reduced libido • Infertility
What are the signs of hypogonadism?
Males • Reduced pubic hair • Soft, small testes • Gynaecomastia • Fine perioral wrinkles • (Delayed puberty – micropenis, high-pitched voice) Cryptorchidism • Undescended testes
Females • Loss of secondary sexual hair • Breast atrophy • Fine perioral wrinkles • (Primary amenorrhea, no 2 sexual characteristics) Turner’s syndrome • Short stature • Low posterior hairline • Webbed neck • High arched palate • Wide carrying angle (cubitus valgus)
Kallmann’s syndrome
• Anosmia
What investigations are carried out for hypogonadism?
Males
• Serum Total Testosterone - <300 ng/dL.
Check between 6 a.m. and 8 a.m. ideally; sample taken up to 11 a.m. is acceptable.
• Serum Albumin and SHBG - to calculate serum free testosterone.
<5 ng/dL generally indicates hypogonadism.
• Serum FSH and LH - to determine whether it’s primary or secondary hypogonadism
• Serum Prolactin: - hyperprolactinaemia may be the cause of hypogonadism.
• Karyotype - to exclude/ diagnose Klinefelter’s syndrome in primary hypogonadism.
• Secondary Hypogonadism:
- Pituitary function tests.
- Perimetry
- Smell Tests
- Iron studies and ferritin for hereditary haemochromatosis.
• Pituitary MRI - shows a suprasellar growth in the case of secondary hypogonadism.
• DEXA - hypogonadism can cause a decrease in bone density
• Semen Analysis
- sperm count below 5 million/mL indicates severe oligozoospermia.
Females
• Serum Oestradiol - low
• Serum FSH and LH - to determine whether it is primary or secondary hypogonadism.
• Investigate the Causes:
Primary:
- Karyotype to look for chromosomal abnormalities: complete or partial deletion of the X chromosome in Turner’s syndrome, or the presence of a Y chromosome.
- Pelvic imaging (ultrasound ± MRI): in patients with primary amenorrhoea, to demonstrate the presence or absence of the uterus and vagina and vaginal or cervical outlet obstruction (Mullerian agenesis, androgen insensitivity, transverse vaginal septum, imperforate hymen).
Secondary:
Pituitary function tests.
- Prolactin
- Perimetry
- Smell Tests
- Iron studies and ferritin for hereditary haemochromatosis.
• Investigation of the associated conditions
- Turner’s syndrome: Periodic echocardiography and cardiology follow-up, Renal ultrasound.
- Autoimmune oophoritis: Evaluate for autoimmune adrenal insufficiency (by measuring 21-hydroxylase antibodies and if positive, an ACTH stimulation test)
