A 45-year-old man comes to the office due to loss of sexual desire and failure to attain satisfactory erections during intercourse. He has no morning erections. The patient has no leg or buttock pain with exertion but has had intermittent bilateral hand pain. Medical history is significant for type 2 diabetes mellitus and recent-onset peripheral neuropathy. He does not use tobacco or alcohol. The patient has a 12-year-old child from a previous marriage and now lives with his second wife. Blood pressure is 120/70 mm Hg and pulse is 70/min. BMI is 24 kg/m2. The neck is supple with no thyromegaly or lymphadenopathy. Cardiopulmonary examination is normal. The abdomen is soft and nontender with palpable hepatomegaly. Genital examination shows small testes bilaterally but otherwise normal secondary sexual characteristics. Peripheral pulses are 2+, and capillary refill in the feet is normal. Neurologic examination demonstrates normal deep tendon reflexes and muscle strength; sensation is mildly decreased in both ankles. Visual field testing is normal. What is the best next step in management of this patient?
Hereditary hemochromatosis | |
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Diagnosis |
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Management |
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This patient has hypogonadism presenting with decreased libido and erectile dysfunction (ED); the loss of morning erections suggests an organic rather than psychogenic cause of ED. In addition, he has features suggestive of hereditary hemochromatosis (HH), including diabetes mellitus (despite a normal BMI), joint pain, and hepatomegaly. HH is due to excessive absorption of iron and deposition of excess iron in the tissues. HH can cause secondary hypogonadism due to iron deposition in the pituitary, which impairs production of gonadotropins (and often other pituitary hormones), leading to decreased testicular testosterone production and testicular atrophy.
Initial assessment of iron stores in patients with suspected HH should include serum iron, serum ferritin, and transferrin saturation (ie, serum iron/total iron binding capacity × 100). The diagnosis is confirmed with HFE genetic testing. Concurrently, hypogonadism can be assessed with serum testosterone, FSH, and LH, which are characteristically low. Treatment includes therapeutic phlebotomy.
(Choice A) Klinefelter syndrome (ie, 47,XXY by karyotype analysis) can cause hypogonadism; however, patients are typically infertile (this patient has a child). Also, Klinefelter syndrome does not cause joint pain or hepatomegaly.
(Choice B) Nocturnal polysomnography is used as an initial test for obstructive sleep apnea, which can be associated with erectile dysfunction. Obstructive sleep apnea is common in patients with diabetes but is typically seen in those with significant obesity. This patient has a normal BMI and no specific symptoms (eg, morning headache) of sleep apnea.
(Choices C and F) Testosterone replacement can treat hypogonadal symptoms (eg, decreased libido), and phosphodiesterase-5 inhibitors (eg, sildenafil) can often improve erectile function. These interventions may be useful for this patient later but may be unnecessary if phlebotomy restores gonadal function. Empiric treatment without proper diagnostic evaluation can lead to serious complications of HH, such as heart failure and cirrhosis. This patient has a normal BMI, which indicates that his diabetes (and neuropathy) could be due to underlying undiagnosed HH rather than insulin resistance from obesity.
(Choice D) Scrotal ultrasound is typically performed in patients with possible testicular malignancy (eg, scrotal mass) or other structural abnormalities (eg, hydrocele). It is unlikely to be helpful in evaluation of bilateral testicular atrophy.
Educational objective:
Hereditary hemochromatosis can cause secondary hypogonadism due to iron deposition in the pituitary with deficient production of gonadotropins. Initial assessment should include serum iron, serum ferritin, and transferrin saturation. The diagnosis is confirmed with HFE genetic testing. Treatment includes therapeutic phlebotomy.