What is Prolactin?

Prolactin is a  hormone  that is produced by the pituitary gland, a gland located at the base of the skull, and is extremely important for the proper functioning of the human body. For chemistry, prolactin is more precisely a  protein  and its main task is essential for new mothers after childbirth: prolactin is necessary to promote the production of  milk  after childbirth and its values ​​also increase thanks to the stimulation that the breast receives by the newborn during sucking.

Precisely because it is a typically female hormone, men are very concerned when it comes to prolactin in reference to their health. However, the prolactin hormone is also produced by man  because it is also useful for various other functions, necessary for the regulation of many of the body:

• helps the maturation of the mammary glands of the woman’s breast;
• acts on the menstrual cycle;
• influences sexual behavior (both genders);
• affects the immune system (both genders);
• acts on the metabolism (both sexes).

In general, the production of prolactin is regulated and inhibited by another hormone:  dopamine . For pregnant women, prolactin values ​​increase to inhibit the menstrual cycle and prepare the mother’s body for milk production in the postpartum period.

As prolactin increases, estrogen and progesterone decrease .

Prolactin: abnormal values ​​and pathologies

Hyperprolactinaemia is a condition characterized by an excess of prolactin in the blood . This type of pathology affects both women (who are not expecting a child) and men indifferently. It is a fairly frequent disorder among women who are of childbearing age, but with an absent or inconstant menstrual cycle, and who have low levels of FSH in their blood.

In subjects with  reduced pituitary function  it is also possible to find an insufficient amount of the hormone, in this case we speak of hypoprolactinaemia or low prolactin.

The main concern arises because about 30% of pituitary tumors produce prolactin. Prolactin is normally synthesized in the pituitary gland by specialized cells: the lactotrophs. The precise role of prolactin in humans is not fully describable, but the secretion of prolactin, even in male subjects, is regulated by the hypothalamic hormone called dopamine.

Dopamine normally inhibits the production of prolactin , but an increase in prolactin may occur if there is an abnormal process that decreases dopamine production.

In  men with high prolactin levels,  a condition called hypogonadism may occur, causing low blood testosterone levels , decreased libido and decreased normal sexual function. One type of disease that causes prolactin to rise is a prolactinoma.

Prolactinoma   is a benign pituitary tumor, therefore non-cancerous, and is composed of lactotrophs, or cells that produce prolactin . In most cases prolactinomas present as large in size by the time a diagnosis is reached. Patients often notice symptoms when the mass has already developed. The larger the tumor, the higher the prolactin values.

Symptoms and causes

If  symptoms  such as sexual dysfunction and loss of sexual desire persist over time you could think of an increase in prolactin in your body, generally these are symptoms that are enough to suspect an anomaly in the production of this hormone.

Some patients may also experience:

• headache;
• difficulty in peripheral vision;
• double vision (diplopia).

These  symptoms appear due to the mass  pressing on the brain. In these cases, the doctor immediately orders a blood test. Blood prolactin levels exceeding 50 ng/mL are indicators of hyperprolactinaemia.

Hyperprolactinemia causes different and very varied symptoms, but all associated with pituitary problems :

• gynecomastia;
• increase in adipose tissue;
• infertility;
• decrease in muscle mass;
• decrease in the amount of hair;
• galactorrhea (rare);
• constipation;
• swollen hands and feet;
• jaw swelling;
• swollen tongue;
• low pressure;
• loss of eyebrows;
• lethargy;
• epistaxis;
• nausea;
• He retched;
• irritability;
• cold intolerance;
• heat intolerance;
• epilepsy.

High prolactin values ​​are not always synonymous with a pituitary tumor. In many cases, some drugs cause prolactin elevations as high as 100-150 ng/mL. Drugs that affect prolactin are:

• antidepressants;
• blood pressure medications;
• antipsychotics;
• medicines to treat ulcers;
• anti-nausea medications;
• painkillers (opiate-based).

Even  particularly strong stressful situations  can cause an increase in prolactin. Various diseases affecting the hypothalamic area, such as inflammation or other types of non-pituitary tumors, can also cause prolactin levels to rise in the blood .

Other cases in which prolactin levels may be abnormal are:

• after a heart attack;
• following a prolonged fast;
• anxiety;
• after strenuous physical activity.

Unfortunately  , if the prolactin values ​​​​in the blood exceed 200 ng / ml  , the diagnosis of prolactinoma is almost never avoided.

The most common causes of excessive prolactin production, in addition to those listed, remain pituitary tumors, fortunately they are often benign. Other pathologies that affect prolactin are:

• hypothyroidism;
• liver disorders;
• chronic kidney disease.

Diagnosis

Making an immediate and perfect diagnosis of a hyperprolactinaemia case is not easy for doctors. Although it is a hormone that is found in normal blood tests, the  symptoms  are not always linked to hyperprolactinemia.

It is therefore necessary to carry out  a series of clinical tests  to be sure of the diagnosis, this is because prolactin is an unstable hormone that changes its concentration in the blood very quickly. As anticipated,  stress  is the main responsible for the change in the levels of prolactin in the blood.

In fact, even simple blood sampling (especially fear of the needle) can cause prolactin levels to rise, which is why 3 blood samples are generally performed half an hour apart.

The range of normal values ​​of prolactin in the blood is 0-20 ng/mL, if the values ​​are higher we speak of hyperprolactinaemia.

The doctor usually orders a  blood test  that can measure the level of prolactin if the patient experiences the symptoms listed above. If the value is high, the doctor often recommends repeating the exam to eliminate any doubts. The sampling must be done on an empty stomach and in a moment of tranquillity.

If the level of prolactin in the blood is also high on the second blood test, the doctor generally also prescribes tests that are useful to rule out diseases of the thyroid or affecting the kidneys. If the thyroid gland and kidneys are functioning normally, the doctor will order the patient to have an MRI or CT scan. These tests can help identify pituitary tumors.

An MRI or CT scan may also simply discover a  lump . Depending on the size, we speak of microadenoma if it is small and of macroadenoma if it exceeds 1 cm in size.

In humans , normal prolactin values ​​are   18 ng/mL, but most experience values ​​of around 6-7 ng/mL. When a value higher than 250 ng/ml is obtained, the diagnosis of prolactinoma is very likely.

Care and therapy

People who have high prolactin values , but do not experience any symptoms, generally do not need any treatment because the treatment depends on what is causing the problem. In the case of a prolactinoma, drug treatment is generally opted for. The dose of the drugs is calibrated according to the patient’s needs and serves to bring the values ​​back into the normal range.

Generally the duration of the treatment is at least two years, after this period of time it is possible to verify if the tumor is in regression: in this case it is also possible to opt for the interruption of the therapy. In any case, periodic check-ups will be prescribed to the patient in the two years.

In very rare cases, radiation therapy may be required. In the event that  the hyperprolactinaemia is induced by a drug  , the doctor will have to find a valid alternative to the drug that the patient normally takes. Not all drugs of the same type have the same side effects.

It is essential that the patient does not interrupt the therapy  without the doctor’s consent. In case of high prilactin due to hypothyroidism, the pharmacological therapy will be based on drugs for the regulation of thyroid functions.

The pituitary tumor: brief focus

A pituitary tumor is an abnormal growth in the pituitary gland, the part of the brain that regulates hormones in the human body. The pituitary gland is a type of endocrine gland that is about the size of a pea and is located at the base of the brain.

The pituitary gland is essential in regulating and controlling the release of hormones such as:

• thyroid stimulating hormone (or TSH ) ;
• the adrenocorticotropic hormone (or ACTH);
• growth hormone (or GH);
• Prolactin.

Nearly 80% of pituitary tumors release hormones and cause:

• an excess of thyroid-stimulating hormone
• Cushing’s syndrome causing excess adrenocorticotropic hormone
• gigantism (excess growth hormone)
• acromegaly (excess growth hormone)

The causes of various pituitary tumors are still unknown today, but in some rare cases the disease is inherited and is called multiple endocrine neoplasia I (or MEN I). There are various types of tumors that can be found in the same area of ​​the head and look similar to a pituitary tumor:

• craniofaringioma;
• germinoma;
• metastatic tumors;
• cyst.

Only 15% of tumors found in the skull are pituitary tumors, fortunately most pituitary tumors are non-cancerous and therefore benign.

Tests to find a pituitary tumor also check for:

• insulin growth factor-1 (or IGF-1) levels
• luteinizing hormone (or LH) levels;
• cortisol levels;
• follicle stimulating hormone (or FSH) levels;
• thyroid hormone levels (free T4 also known as TSH test);
• serum prolactin levels;
• testosterone/estradiol levels.

The essential additional tests to confirm the diagnosis are:

• visual field test;
• MRI.

Pituitary tumors could press on the optic nerves and cause blindness, so they need to be treated promptly. If the doctor chooses to eliminate the tumor surgically, and not pharmacologically, it can be eliminated through the nose and sinuses. The operation must be performed under general anesthesia but the intervention is quite simple.

Some types of pituitary tumors cannot be removed this way and will need to be removed through the skull. This type of surgery is more complex than removing the tumor through the sinuses.

Radiation  therapy  could be a valuable aid in shrinking the tumor. Generally the prognosis is good and if the tumor can be eliminated and reduced by drugs or surgically removed, the patient’s prospects for recovery are very good.

Removing the tumor could cause hormonal imbalances which can be treated with hormone treatments specially tailored to the patient. Only blindness caused by the tumor pressing on the optic nerve could be permanent damage. For this reason it is advisable to intervene promptly on the tumor. An early diagnosis could prevent the patient from irreversible complications and disabilities such as loss of vision.

If you think you have symptoms associated with hyperprolactinemia or pituitary tumor, contact your doctor right away. Avoid neglecting your health and also avoid DIY remedies. The health of our body is important and ignoring the problem will not make it disappear, remember to put aside fears and embarrassments and that in this case your doctor could help you get back to normal.

The support of family and loved ones is also essential to overcome the problem. Remember that asking for help is important.