Thursday, January 24, 2013
1:38 PM | Posted by Shams Burki | Edit Post
Clinical Vignette: A 36-year-old male with insulin-dependent diabetes mellitus of three years duration presented with decreased libido and erectile dysfunction since diagnosis. No abnormalities were noted on genital examination. Investigations revealed:
- plasma testosterone 6.0 nmol/L (9 - 35)
- plasma follicle stimulating hormone 1.0 u/L (1-8)
Which of the following investigations is most appropriate next step?
- autonomic function testing
- Doppler studies of penile artery
- Nerve conduction studies
- Serum ferritin
- Serum prolactin
Answer to clinical vignette|case: (4)
Haemochromatosis typically causes hypogonadotrophic hypogonadism as a consequence of the ferritin deposition within the pituitary rather than primary testicular dysfunction.
Autonomic nerve dysfunction is one of the commoner causes of impotence in a diabetic but in this case is not the cause of his HH. For similar reasons, both nerve conduction studies and dopplers are irrelevant.
Prolactin would be a sensible measurement but probably if you were looking to confirm a diagnosis that incorporates the diabetes as well, Ferritin would be the investigation of choice.