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2. A 62-year-old man complains of a 5-year history of progressive
erectile failure and recent loss of libido. He acknowledges wors-
ening fatigue and lethargy, morning headaches, and about 6.8
kg of weight gain over the past year, but he denies other neuro-
logic symptoms. He has become less physically active in recent
years because of his occupation as a business manager. His cur-
rent medications include atorvastatin 20 mg daily, aspirin 81 mg
daily, and atenolol 50 mg daily, prescribed for high blood pres-
sure 10 years ago. A permanent pacemaker was inserted for heart
block 6 years ago. On physical examination, he is overweight
with abdominal adiposity. His pulse is 68 beats per minute and
the blood pressure is 144/86 mm Hg. There is assymetric (right
> left) gynecomastia, with mild breast tenderness bilaterally.
Testicular examination reveals normal-sized testes (20 mL), which
are soft. Male secondary sexual characteristics are normal. His
visual fields are normal to confrontation. A CT scan reveals no
evidence for a pituitary macroadenoma. Laboratory data include
the following: total testosterone 127 ng/dL, TSH 0.8 mIU/L,
free thyroxine 0.9 ng/dL, morning cortisol 18 mcg/dL, prolactin
35 ng/mL, sodium 138 mEq/L, potassium 4.2 mEq/L, and cre-
atinine 1.2 mg/dL. What would you do next?


a. Refer to a neurosurgeon for transsphenoidal surgery.
b. Prescribe bromocriptine or other dopamine-agonist therapy.
c. Prescribe testosterone supplementation through a percuta-
neous route.
d. Check serum luteinizing hormone (LH) and follicle-stim-
ulating hormone (FSH) concentrations.
e. Perform an MRI to obtain adequate imaging of the pitu-
itary gland.
Good luck

BB

d. Check serum luteinizing hormone (LH) and follicle-stim-
ulating hormone (FSH) concentrations.

D. prolactin level is normal

D

2. Answer d.
He has clear evidence of acquired hypogonadism, with symptoms,
signs, and biochemical support for low testosterone concentrations.
The initial evaluation of hypogonadism should be to distinguish pri-
mary (gonadal) from secondary (central) causes since this indicates
the appropriate approach to further evaluation and therapy. The pro-
lactin concentration is not high enough to strongly suggest a pituitary
prolactinoma and may reflect the stress of drawing a blood sample or
of concurrent illness. MRI cannot be performed in a patient with a
pacemaker in situ. Although testosterone replacement would cor-
rect the low testosterone, this is not an appropriate treatment for this
man with probable central hypogonadism, which may reflect his
untreated sleep apnea.

Good luck