A 33-year-old man with poorly controlled type 2 diabetes presents with decreased libido and infertility. He has used metoclopramide chronically for severe gastroparesis. Vital signs are normal (BP 128/82, HR 72, RR 16, Temp 98.6°F). Laboratory studies show prolactin 85 ng/mL (normal <20), testosterone 180 ng/dL (normal 300-1000), and LH 2.1 mIU/mL (normal 1.7-8.6). HbA1c is 9.2%. Erectile dysfunction testing is normal. Which mechanism best explains his hypogonadism?
- A)Inhibition of hypothalamic GnRH releaseGABARITO
- B)Overproduction of adrenal androgens
- C)Direct destruction of Leydig cells by prolactin
- D)Upregulation of Sertoli cell inhibin B
- E)Suppression of TSH receptor signaling
Explicação
Hyperprolactinemia suppresses hypothalamic GnRH secretion. Reduced GnRH lowers LH and FSH, leading to decreased testosterone production and infertility or low libido. Dopamine antagonists such as metoclopramide are classic medication causes of prolactin elevat... Ver explicação completa e trilha adaptativa →