Hypogonadism

Question 1

Define hypogonadism.

Answer 1

Hypogonadism in males is a clinical syndrome that comprises symptoms and/or signs, along with biochemical evidence of testosterone deficiency.

Question 2

Explain the aetiology/risk factors of hypogonadism.

Answer 2

Genetic anomaly
Type 2 diabetes mellitus
Use of alkylating agents, opioids, or glucocorticoids
Use of exogenous sex hormones and GnRH analogues
Hyperprolactinaemia
Pituitary tumour or apoplexy
Critical illness
Testicular damage

Question 3

Summarise the epidemiology of hypogonadism.

Answer 3

The prevalence of hypogonadism increases with age. About a quarter of the US male population have total testosterone levels that are below 10.4 nanomol/L (<300 nanograms/dL) (considered by many experts to be the lower end of normal).

Question 4

Recognise the presenting symptoms of hypogonadism. Recognise the signs of hypogonadism on physical examination.

Answer 4

Decreased libido
Loss of spontaneous morning erections
Erectile dysfunction
Gynaecomastia
Infertility
Decreased energy and fatigue
Delayed puberty
Decreased muscle mass and strength
Loss of axillary and pubic hair
Lack of facial hair
Poor concentration and memory
Depressed moo
Sleep disturbance
Hot flushes and sweats
Increasing BMI
Tall stature
Fine wrinkling of facial skin

Question 5

Identify appropriate investigations for hypogonadism and interpret the results.

Answer 5

Serum total testosterone
Serum sex hormone binding globulin (SHBG)
Serum free testosterone
Serum LH/FSH