A 50-year-old man presents to the clinic with complaints of decreased libido, difficulty with erections, and fatigue over the past 6 months. He also notes a decrease in his muscle mass and occasional breast tenderness. Past medical history is unremarkable, and he does not take any medications or supplements. He consumes 4 beers daily. He does not smoke cigarettes or use marijuana. alcohol regularly. Vital signs are within normal limits. On physical examination, he has bilateral gynecomastia and small testes. Laboratory findings are as follows:
B) Chronic liver disease
Chronic liver disease can cause hypogonadism in men, which is characterized by low testosterone levels, loss of libido, small testes, erectile dysfunction, and gynecomastia. These symptoms are more common in men with advanced liver disease, and testosterone levels tend to decrease as the disease worsens. In fact, low testosterone levels are associated with worse clinical outcomes and mortality. This patient's symptoms of hypogonadism (decreased libido, erectile dysfunction, gynecomastia, and small testes) and laboratory findings of low total T3 and T4 with normal TSH are indicative of chronic liver disease. Chronic liver disease can cause hypogonadism due to primary gonadal injury or hypothalamic-pituitary dysfunction. Additionally, liver disease can lead to increased levels of estradiol due to decreased metabolism and increased conversion from androgens, resulting in gynecomastia. Chronic liver disease also affects thyroid hormone binding proteins, decreasing the synthesis of these proteins and leading to low levels of total T3 and T4 while maintaining normal free T4 levels, reflecting a euthyroid state.
Answer choice A: Adrenal insufficiency, is incorrect. Adrenal insufficiency would present with fatigue, weight loss, and features of hypogonadism but would not cause the specific thyroid hormone abnormalities seen here.
Answer choice C: Exogenous thyroxine intake, is incorrect. Exogenous thyroxine intake would suppress TSH.
Answer choice D: Hashimoto thyroiditis, is incorrect. Hashimoto thyroiditis would typically show elevated TSH and low free T4.
Answer choice E: Penile vascular occlusion, is incorrect. Penile vascular occlusion would cause erectile dysfunction but not gynecomastia or thyroid hormone abnormalities.
Answer choice F: Testosterone insensitivity, is incorrect. Testosterone insensitivity is a genetic condition that would present earlier in life with features of primary hypogonadism and normal or elevated testosterone levels.
Key Learning Point
Chronic liver disease can cause hypogonadism and gynecomastia due to increased estradiol levels and low total T3 and T4 with normal TSH, reflecting altered thyroid hormone binding protein levels but a euthyroid state.
