How to check for hyperprolactinemia

Hyperprolactinemia is the most common pituitary disease and one of the important factors causing infertility in women. The examination and diagnosis of hyperprolactinemia is of great reference significance for the accurate treatment of the disease. Below, the editor will give you a detailed introduction to the hyperprolactinemia examination items.

1. Determination of reproductive hormones in the hypothalamus-pituitary-ovarian axis

FSH and LH decrease, and the LH/FSH ratio increases. For example, PRL 100ng/ml is mostly functional, and PRL 100ng/ml is mostly tumor-related. The larger the tumor, the higher the PRL. For example, if the tumor diameter is 5mm, the PRL is (171/38)ng/ml; if the tumor diameter is 5-10mm, the PRL is (206/29)ng/ml; if the tumor diameter is 10mm, the PRL is mostly (485/158)ng/ml. Plasma PRL may not increase when giant adenomas bleed and necrotize.

2. Thyroid, adrenal and pancreatic function tests

When hyperprolactinemia is combined with hypothyroidism, TSH increases, and T3, T4, and PBI decrease. When hyperprolactinemia is combined with Cushing's disease and virilization symptoms, testosterone (T), androstenedione (△4dione), dihydrotestosterone (DHT), dehydroepiandrosterone (DHEA), 17-ketosteroids (17KS), and plasma cortisol increase. When hyperprolactinemia is combined with diabetes and acromegaly, plasma insulin, blood sugar, and glucagon should be measured and a glucose tolerance test should be performed.

3. Prolactin stimulation test

(1) Thyrotropin-releasing hormone (TRH) test:

After a single intravenous injection of TRH 100-400 pg in normal women, PRL will increase 5-10 times and TSH will increase 2 times within 15-30 minutes compared to before injection. There will be no increase in patients with pituitary tumors.

(2) Chlorpromazine test:

Chlorpromazine inhibits norepinephrine reabsorption and dopamine function through receptor mechanism, and promotes PRL secretion. In normal women, after intramuscular injection of 25-50 mg of chlorpromazine, blood PRL increases 1-2 times compared with before injection 60-90 minutes, and lasts for 3 hours. It does not increase in pituitary tumors.

(3) Metoclopramide test:

Metoclopramide promotes the production and release of PRL. In normal women, 30 to 60 minutes after intravenous injection of 10 mg, PRL increases by more than 3 times compared with before injection, but does not increase in pituitary tumors.

4. Prolactin suppression test

(1) Levodopa test:

Levodopa is a dopamine precursor that is converted into dopamine by decarboxylase, inhibiting the production and secretion of PRL. In normal women, PRL is significantly reduced 2 to 3 hours after oral administration of 500 mg, but it does not decrease in patients with pituitary tumors.

(2) Bromocriptine test:

Levodopa is a dopamine receptor agonist that inhibits the production and release of PRL. In normal women, PRL decreases by more than 50% 2 to 4 hours after taking 2.5 to 5 mg orally, and lasts for 20 to 30 hours. In patients with functional hyperprolactinemia and prolactinoma, prolactin is significantly reduced after taking the drug, while GH and ACTH are reduced, but GH and ACTH are not significantly reduced.

5. Sella turcica computed tomography (CT) examination

In normal women, the anterior-posterior diameter of the sella turcica is <17mm, the depth is <13mm, the area is <130mm2, and the volume is <1100mm3. CT scan should be performed if the following images are present: ① sailboat-like enlargement; ② double sella turcica bottoms or double edges; ③ high/low density areas or inhomogeneity in the sella turcica; ④ plate deformation; ⑤ calcification foci above the sella turcica; ⑥ osteoporosis of the anterior and posterior clinoid processes; ⑦ cavitation in the sella turcica; ⑧ bone destruction.

6. Magnetic resonance imaging (MRI)

Cavernous sinus angiography, pneumoencephalography, and cerebral angiography can determine the location and size of the tumor and help differentiate it from other intracranial lesions. Since the false positive and false negative rates of CT diagnosis are 20% and the accuracy rate is only 61%, MRI is recommended for diagnosis.

7. Eye exam

It includes examination of vision, visual field, intraocular pressure, and fundus to determine whether there are signs of intracranial tumor compression (bitemporal visual field hemianopsia, decreased vision, blindness, nausea, vomiting, and headache, etc.).

The above is an introduction to the examination items for hyperprolactinemia. I hope it will be helpful to you.