Initial diagnosis of hyperprolactinemia

Hyperprolactinemia is the most common pituitary disease, which is characterized by galactorrhea and hypogonadism. If a patient with hyperprolactinemia has galactorrhea and amenorrhea at the same time, it is called galactorrhea-amenorrhea syndrome. Galactorrhea-amenorrhea syndrome that occurs after childbirth is called Chiari-Frommel syndrome; if accompanied by pituitary tumors, it is called Forbes-Al-bright syndrome, and if it is not postpartum and not accompanied by pituitary tumors, it is called delCastillo syndrome.

If the prolactin level is between 25 and 40 ng/ml, the answer is no. Because a single blood test shows that the prolactin level is higher than normal, it is not enough to diagnose hyperprolactinemia. Because prolactin is secreted in a pulsed manner, and stress can increase the secretion of prolactin. Hyperprolactinemia can only be diagnosed after other causes of elevated prolactin are excluded by taking a medical history (especially medication history), a pregnancy test, and checking thyroid and kidney function.

Patients with galactorrhea and hypogonadism should consider the possibility of high PRL, which can be diagnosed by measuring blood PRL. Normal male blood PRL generally does not exceed 0.68nmol/L (15ng/ml), and female blood PRL is generally 0.23-0.91nmol/L (5-20ng/ml). Since PRL is pulsatile and affected by many factors, it is best to repeat the measurement. It is worth noting that a few people have normal blood PRL in the morning but elevated blood PRL at night. These patients need to measure the nighttime blood PRL level and do a provocation test. Commonly used provocation tests include TRH test and metoclopramide (metoclopramide) test. The TRH excitation test is to inject TRH 400-500ug intravenously on an empty stomach, and collect blood for PRL at 0, 15, 30, 45, 60, 90, and 120 minutes respectively. After normal people are injected with TRH, PRL increases, and the peak value appears 15-30 minutes after injection, which is about 5 times the base value (3-5 times for men and 5-8 times for women). The dose of metoclopramide test is 10 mg, which can be taken orally, or injected intravenously or intramuscularly. The PRL peak value appears 60 to 120 minutes after oral administration, and the peak value appears 20 to 60 minutes after intravenous or intramuscular injection. The peak value of normal people is more than 3 times the base value. PRL tumor patients are slow to respond to TRH and metoclopramide, and the multiple increase of PRL after administration is not as high as that of normal people, but the absolute value of the increase is higher than that of normal people.