Male Hypogonadism

Question 1

What is male hypogonadism?

Answer 1

Syndrome of decreased testosterone production, sperm production or both

Question 2

How can male hypogonadism be classified?

Answer 2

Primary: dysfunction of testes resulting in failure of spermatogenesis +/or testosterone production

Secondary: dysfunction of hypothalamus/ pituitary

Question 3

Give 3 causes of primary male Hypogonadism

Answer 3

Gonadal dysgenesis (e.g. Klinefelter’s syndrome, cryptorchidism)

Gonadal damage (e.g. infection, torsion, trauma)

Question 4

What is the most common infection that can cause primary hypogonadism?

Answer 4

Mumps orchitis

Question 5

Name a condition that can cause primary or secondary hypogonadism

Answer 5

Haemochromatosis
Too much iron in blood can cause testicular failure or pituitary gland dysfunction

Question 6

Give 5 causes of secondary male Hypogonadism

Answer 6

Pituitary/ Hypothalamic lesions
GnRH deficiency (Kallmann’s syndrome)
Hyperprolactinaemia
Drugs/ substance misuse
Systemic diseases

Question 7

List 5 drugs that can cause secondary hypogonadism

Answer 7

Opioids
Cannabinoids
High dose glucocorticoids
Exogenous oestrogens + androgens
GnRH analogues

Question 8

List 4 S/S of male Hypogonadism

Answer 8

Decreased libido
Loss of spontaneous morning erections
Erectile dysfunction
Infertility

Question 9

Which signs on examination are more common in primary hypogonadism?

Answer 9

Gynaecomastia
Decrease in size of testes if the hypogonadism develops after puberty

Question 10

What may be used to measure testicular volume?

Answer 10

Prader’s orchidometer (normal adult vol = 15-25 mL)

Question 11

List 4 signs of male hypogonadism in adolescents

Answer 11

Small genitalia
Difficult gaining muscle mass despite vigorous exercise
Lack of facial hair
Failure of voice to deepen
Eunuchoid proportions

Question 12

Describe signs of male hypogonadism in adults

Answer 12

Decreased vigor + libido + depressed mood (weeks)
Decreased muscle mass + body hair (years)

Question 13

What can be measured in the blood in suspected male Hypogonadism?

Answer 13

Serum total testosterone
Sex hormone binding globulin (SHBG): check this is not the reason for low free testosterone
Albumin
LH + FSH

Question 14

What are the levels of testosterone, LH and FSH in primary Male Hypogonadism?

Answer 14

Low testosterone
High LH + FSH

Question 15

What are the levels of testosterone, LH and FSH in secondary male hypogonadism?

Answer 15

Low testosterone
Inappropriately normal/ low LH + FSH

Question 16

What investigation can be used in primary male Hypogonadism?

Answer 16

Karyotyping (check for Klinefelter’s syndrome)

Question 17

What investigations can be used in secondary male Hypogonadism?

Answer 17

Pituitary function tests
MRI of the hypothalamic/pituitary area
Visual field testing
Smell testing (for anosmia)
Iron testing (for hereditary haemochromatosis)
Assess bone age (risk of fracture)

Question 18

List 5 signs of Prader-Willi syndrome

Answer 18

Short
Small hands
Almond-shaped eyes
Learning difficulty
Postnatal hypotonia

Question 19

List 4 signs of Laurence-Moon-Biedl syndrome

Answer 19

Obesity
Polydactyly
Retinitis pigmentosa
Learning difficulty

Question 20

Describe management of male hypogonadism

Answer 20

Treat underlying cause
Testosterone therapy
Discuss fertility plans (assisted reproductive therapy e.g. IVF)

Question 21

Describe delivery of testosterone therapy

Answer 21

Transdermal: gel/ patch daily

IM Injection: short acting (every 1-4w) or long acting (every 8-12w)