Małe hypogonadism Flashcards

1
Q

How is testosterone circulated?

A

98 - 99.5% is bound to sex-hormone binding globulin (SHBG) and albumin

0.5-2% is free

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2
Q

What hormones is testosterone converted into?

A

Dihydrotestosterone (Highly active form) and oestradiol

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3
Q

What is male hypogonadism?

A

A clinical syndrome comprising of signs, symptoms and biochemical evidence of testosterone deficiency

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4
Q

What is meant by primary hypogonadism?

A

Condition affecting the testes

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5
Q

What is meant by secondary hypogonadism?

A

Condition affecting the hypothalamus or anterior pituitary

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6
Q

What are some features of pre-pubertal onset hypogonadism?

A
  • Small male sexual organs (Testes, penis, prostate)
  • Decreased body hair
  • High pitched voice
  • Low libido
  • Gynaecomastia
  • Eunuchoidal habitus (Tall, Slim, Long arms and legs)
  • Decreased bone and muscle mass
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7
Q

What are some post-pubertal symptoms of male hypogonadism?

A
  • Normal skeletal proportions, penis size and voice
  • Decrease libido
  • Decreased spontaneous erections
  • Decreased pubic/axillary hair
  • Reduced shaving frequency
  • Decreased testicular volume
  • Gynaecomastia
  • Decreased muscle and bone mass
  • Decreased energy and motivation
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8
Q

Describe the pathophysiology of primary hypogonadism

A
  1. Decreased testosterone
  2. Decreased negative feedback
  3. Increased LH/FSH production
  4. Hypergonadotrophic hypogonadism
  5. Spermatogenesis decreased moreso than testosterone
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9
Q

What are some congenital causes of primary hypogonadism?

A
  • Klinefelter’s syndrome
  • Cryptorchidism
  • Y-chromosome microdeletions
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10
Q

What are some acquired causes of primary hypogonadism?

A
  • Testicular trauma/torsion
  • Chemotherapy/radiation
  • Varicocele
  • Orchitis (mumps)
  • Infiltrative diseases e.g. haemochromatosis
  • Medications e.g. glucocorticoids, ketoconazole
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11
Q

Describe the pathophysiology of secondary hypogonadism?

A
  1. Decreased LH/FSH production
  2. Decreased testosterone
  3. Spermatogenesis and testosterone production equally affected
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12
Q

What are some congenital causes of secondary hypogonadism?

A
  • Kallmann’s syndrome
  • Prader-Willi syndromeW
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13
Q

What are some acquired causes of secondary hypogonadism?

A
  • Pituitary damage
  • Hyperprolactinaemia
  • Obesity, diabetes
  • Medications (steriod, opiods)
  • Acute systemic illness
  • Eating disorders, excessive exercise
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14
Q

What are some causes of pituitary damage leading to secondary hypogonadism?

A
  • Tumours
  • Infiltrative disease
  • Infection (TB)
  • Apoplexy
  • Head trauma
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15
Q

What is Kallmann’s syndrome?

A

Genetic disorder that causes that causes hypogonadotropic hypogonadism and an impaired sense of smell

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16
Q

How does Kallmann’s syndrome present?

A
  • Hypogonadism
  • Hyposmia/anosmia
  • Isolated GnRh deficiency also associated with other abnormalities:
    • Unilateral renal agenesis
    • Red-green colour blindness
    • Cleft lip/palate
    • Bimanual synkinesis
17
Q

What are some investigations required in Kallmann’s syndrome?

A
  • Hormone testing
  • Olfactory function testing
  • Genetic testing
18
Q

How is Kallmann’s syndrome managed?

A

Hormone replacement therapy (HRT)

19
Q

What is the most common genetic cause of hypogonadism?

A

Kleinfelter syndrome

20
Q

Describe the genetics of Kleinfelter syndrome

A

Usually genotype 47 XXY, can have 46 XY/47 XXY mosaicism

21
Q

How does Kleinfelter syndrome present?

A
  • Presentation variable and therefore diagnosis can be missed or late
  • Affected men are typically infertile (due to tubular damage) and have small, firm testes
22
Q

How is Kleinfelter syndrome investigated?

A

Karyotyping

23
Q

What are some possible complications of Kleinfelter syndrome?

A
  • Increased incidence of cryptorchidism, learning disability and psychosocial issues
  • Increased risk of breast cancer and non-Hodgkin lymphoma
24
Q

How is male hypogonadism diagnosed?

A
  • AM testosterone
  • LH/FSH levels
25
Q

What does normal AM testosterone show?

A

Hypogonadism is unlikely

26
Q

What should be done if LH/FSH levels are elevated?

A

Suspect hypergonadotrophic hypogonadism (Primary) which requires karyotyping and iron studies to fully diagnose

27
Q

What should be done if LH/FSH levels are low?

A

Suspect hypogonadotrophic hypogonadism (Secondary), which requires prolactin and hormone studies, MRI and iron studies

28
Q

When should AM testosterone be measured?

A

Between 8am and 11am

29
Q

What are some conditions that can decrease testosterone levels?

A

Obesity
Insulin reisstance
Hypothyroidism

30
Q

What treatment is given in hypogonadism, if fertility is important?

A

GnRH or gonadotrophin therapy
Sperm retrieval is used to take soerm samples

31
Q

What are the aims of treatment in hypogonadism, if fertility is not important?

A
  • Establish secondary sexual characteristics
  • Maintain sexual function
  • Improve body composition
  • Improve quality of life
32
Q

What is the main management option in hypogonadism, if fertility is not important?

A

Testosterone replacement therapy under the guidance of endocrinology

33
Q

What are some formulations of testosterone?

A
  • Transdermal gel
  • Oral capsules
  • IM injection
34
Q

What are some contraindications for testosterone therapy?

A

Hormone responsive cancer (E.g. prostate, breast)
Severe sleep apnoea
Heart failure

35
Q

How often is monitoring performed in testosterone therapy?

A

3-6 monthly whilst starting treatment and annually thereafter, testing for DRE and PSA, haematrocit and symptoms of sleep apnoea

36
Q
A