Androgen Deficiency in Men Flashcards
Sx of androgen deficiency in men?
General:
- decrease sense of well being, poor concentration
- tiredness, poor stamina
- mood change: depression, irritability
Sexual:
- reduced libido *
- erectile failure (rare)
Organ specific:
- reduced muscle mass and strength
- Osteoporosis and fracture
- Increased fat mass
- gynaecomastia
- small or shrinking testesq
Clinical presentation of male hypogonadism in 1st trimester
Partial virilisation
Ambiguous genitalia
Complete deficiency: Female external genitalia
Clinical presentation of male hypogonadism in 3rd trimester
Micropenis
Cryptorchidism
Clinical presentation of male hypogonadism pre -puberty
Incomplete pubertal maturation
Testes
Clinical presentation of male hypogonadism adult
Decrease in:
- Libido/ sexual desire ?
- Mood/ libido/ stamina
- Muscle mass/ strength
- BMD
- Increased fat mass
Causes of primary androgen deficiency in men
ACQUIRED Testicular damage: - Trauma, torsion - Orchitis (inflammation for the testes e.g. from mumps) - CTX/RTX/toxins -Drugs: spironolactone/ketoconazole
CONGENITAL:
- Klinefelter Syndrome XXY
- Cryptorchidism
- Mutations in androgen biosynthesis in enzymes
- LH/FSH receptor mutations
- Myotonic dystrophy
Causes of secondary androgen deficiency in men
STRUCTURAL (pituitary/hypot):
- Tumour
- Surgery/radiation/trauma
- Infiltration: Fe overload, sarcoid, histiocytosis
GENETIC:
- Kallman’s syndrome
- Idiopathic HH
FUNCTIONAL:
Hyperprolactinaemia
Morbid obesity
Cushings syndrome
PARTIAL/TRANSIENT
Acute illness
Chronic disease: T2D, HIV, COPD
Drugs: glucocorticoids, opioids, GnRH agonists, anabolic steroids
Ix for androgen deficiency in men
Standard: FBE Electrolytes U & creatinine LFT
Plus:
- Free testosterone of
Ix for androgen deficiency in men
Standard: FBE Electrolytes U & creatinine LFT
Plus:
- Free testosterone and sex hormone binding globulin
- FBE: normocytic normochromic anaemia (testosterone increases EPO)
- Serum LH/FSH, prolactin, oestrodial
- Serum FE, TIBC, ferritin: elevated ferritin and Fe saturation confirms haemochromatosis
- MRI pituitary
- Karyotyping
Which testicular cells produce testosterone?
Leydig cells
Which cells are responsible for spermatogenesis?
Nurse cells with seminiferous tubule involvement
What is the pathophysiology of primary hypogonadism?
Primary hypogonadism is an end organ disease. It occurs due to pathology of either Leydig cells or seminiferous tubules or both. Injury to Leydig cells results in decreased testosterone production, while seminiferous tubule involvement results in decreased or absent spermatogenesis.
What is the pathophysiology of secondary hypogonadism?
Secondary hypogonadism is a central disease. Causes include
A.genetic mutations (resulting in maldevelopment of GnRH neurons),
C. hyperprolactinaemia (causing suppression of GnRH), or
D. destruction/compression of the gonadotrophs (by tumour, trauma, infiltrative diseases, pituitary apoplexy).
B. Chronic diseases such as metabolic syndrome and diabetes can lead to secondary hypogonadism. [10] In secondary hypogonadism gonadotrophin levels are decreased or inappropriately normal, and this results in decreased testicular stimulation, causing decreased spermatogenesis and androgen production.
Prolonged secondary hypogonadism leads to testicular atrophy.
Define primary hypogonadism
dysfunction of the testes resulting in failure of spermatogenesis and/or testosterone production.
Define secondary hypogonadism
dysfunction of the hypothalamus and/or the pituitary gland causing failure to secrete GnRH, LH, or FSH.
