Hyperprolactinemia

Hyperprolactinemia is defined by high prolactin levels in the blood. Prolactin is a hormone produced by the pituitary gland that promotes milk production after delivery. However, prolactin serves many additional functions, including affecting reproductive and metabolic processes. Elevated prolactin levels may cause several symptoms and consequences, so it’s important to understand this issue completely. In this article, we will look at the causes, symptoms, diagnosis, and therapy of hyperprolactinemia.

What is Hyperprolactinemia?

Hyperprolactinemia is defined by high prolactin levels in the blood. Prolactin is a hormone produced by the pituitary gland which increases milk production after childbirth However, prolactin fulfills many additional functions, including affecting reproductive and metabolic processes. High prolactin levels can lead to symptoms and complications, so it’s important to understand this issue completely. In this article, we will look at the causes, symptoms, diagnosis, and therapy of hyperprolactinemia.

What is a pituitary gland?

The pituitary gland, also known as the “master gland,” is a small gland about the size of a pea located near the base of the brain, right behind the hypothalamus. Despite its small stature, the pituitary gland regulates several important biological activities by generating and releasing hormones into the circulation.

The pituitary gland is split into two sections: the anterior pituitary (front half) and the posterior pituitary (back part). Each portion secretes hormones that control development, metabolism, reproduction, and other vital activities.

Causes of Hyperprolactinemia

1. Physiological Causes

Several natural physiological conditions can cause an increase in prolactin levels:

• Pregnancy and Lactation: Prolactin levels increase naturally during pregnancy and lactation to help with milk production.
• Stress: Physical and mental stress can increase prolactin levels.
• Sleep: Prolactin levels increase during sleep, particularly in the early morning.

2. Pathological Causes

Pituitary Tumors (Prolactinomas)

The the most common pathological cause of hyperprolactinemia is a prolactinoma, which is a benign pituitary gland tumor that produces high prolactin levels. These tumors vary in size and are classed as microprolactinomas (less than 10 mm) or macroprolactinomas (more than 10 mm).

Other Pituitary Disorders

Other pituitary diseases, including acromegaly and Cushing’s disease, can lead to hyperprolactinemia.

Hypothyroidism

Underactive thyroid (hypothyroidism) can lead to an increase in thyroid-releasing hormone (TRH), which can increase prolactin production.

Medications

Several drugs may cause hyperprolactinemia, including:

• Antipsychotics (e.g., risperidone, haloperidol)
• Antidepressants (e.g., selective serotonin reuptake inhibitors – SSRIs)
• Anti-nausea drugs (e.g., metoclopramide)
• Hypertension medications (e.g., verapamil)

Other Causes

• Chronic Kidney Disease: Reduced clearance of prolactin.
• Chest Wall Injury or Irritation: Nerve pathways involved in prolactin regulation can be affected.
• Polycystic Ovary Syndrome (PCOS): Can be associated with mild elevations in prolactin levels.

Symptoms of Hyperprolactinemia

The symptoms of hyperprolactinemia can vary greatly depending on the cause or severity of the disorder, and gender.

In Women

• Menstrual Irregularities: Oligomenorrhea (infrequent menstruation) or amenorrhea (absence of menstruation) are common.
• Galactorrhea: Spontaneous flow of milk from the breasts, unrelated to childbirth or nursing.
• Infertility: Due to disrupted ovulation.
• Reduced Libido and Vaginal Dryness: Decreased estrogen levels can lead to sexual dysfunction and discomfort.
• Osteoporosis: Long-term estrogen deficiency can weaken bones.

In Men

• Erectile Dysfunction and Reduced Libido: Elevated prolactin can interfere with testosterone production.
• Gynecomastia: Enlarged breast tissue.
• Infertility: Reduced sperm production.
• Galactorrhea: Rare, but can occur.

In Both Genders

• Headaches and Vision Problems: Particularly with large pituitary tumors (macroprolactinomas) that can compress surrounding structures.
• Mood Changes: Anxiety, depression, and irritability.
• Symptoms Related to Underlying Causes: Such as hypothyroidism or chronic kidney disease.

Diagnosis of Hyperprolactinemia

Medical History and Physical Examination

The diagnosis approach starts with a complete medical history and physical examination. The physician will question about your symptoms, medical history, and medicines. Physical examination may identify symptoms like galactorrhea or visual field abnormalities.

Laboratory Tests

The basic laboratory test for hyperprolactinemia is the determination of blood prolactin levels. Prolactin levels can vary during the day, thus blood samples are often collected in the morning after fasting.

Imaging Studies

If excessive prolactin levels are verified, imaging studies are often performed to discover the underlying reason.

• Magnetic Resonance Imaging (MRI): Preferred for detecting pituitary tumors and other abnormalities.
• Computed Tomography (CT) Scan: An alternative if MRI is contraindicated or unavailable.

Additional Tests

Depending on the probable root reason, further tests may be performed:

• Thyroid Function Tests: To check for hypothyroidism.
• Kidney Function Tests: To assess renal function.
• Pregnancy Test: In women of reproductive age to rule out pregnancy.

Treatment of Hyperprolactinemia

The treatment of hyperprolactinemia is determined by the underlying reason, the severity of the symptoms, and the patient’s general health. Medication, surgery, and lifestyle changes are all potential treatment choices.

Medications

Dopamine Agonists

Dopamine agonists are the primary therapy for hyperprolactinemia induced by prolactinomas and other non-tumor sources. These drugs imitate the function of dopamine, a neurotransmitter that decreases prolactin release.

• Cabergoline: is often preferred due to its higher efficacy and lower side effect profile. It is usually taken twice a week.
• Bromocriptine: Another effective option but may have more side effects compared to cabergoline. It is typically taken daily or twice daily.

Treatment for Underlying Conditions

• Hypothyroidism: Treated with thyroid hormone replacement therapy.
• Medications-Induced Hyperprolactinemia: Switching to alternative medications if possible.

Surgery

Surgery can be recommended if medicine is unsuccessful, not tolerated, or the tumor is causing substantial compression of nearby tissues.

Transsphenoidal Surgery: A minimally invasive surgical approach to remove pituitary tumors.

Radiation Therapy

Radiation treatment is rarely used, however it may be an option for aggressive cancers that do not respond to medicine or surgery.

Lifestyle and Supportive Measures

• Stress Management: Techniques such as yoga, meditation, and counseling can help manage stress, which may contribute to elevated prolactin levels.
• Diet and Exercise: Maintaining a healthy lifestyle can support overall well-being and hormonal balance.

Prognosis and Long-Term Management

The prognosis for individuals with hyperprolactinemia varies based on the underlying cause and response to treatment. Most patients with prolactinomas respond well to dopamine agonists, with significant reductions in prolactin levels and tumor size. Regular monitoring through blood tests and imaging studies is essential to assess treatment efficacy and detect any recurrence.

Switching to alternative medicines often cures medication-induced hyperprolactinemia. In situations involving other medical disorders such as hypothyroidism or chronic renal disease, treating the underlying ailment often restores prolactin levels.

Long-term management may include:

Regular Follow-Up: A doctor or nurse should conduct periodic evaluations to check prolactin levels and symptoms.

Bone Health Monitoring: Women with long-term estrogen insufficiency must take extra precautions to avoid osteoporosis.

Fertility Counseling: Reproductive endocrinologists can offer specialist treatment to those who are suffering from infertility.