Hyperprolactinaemia is an endocrine disorder, during which luteotropic hormone level, also known as prolactin, is raised. Prolactin is naturally produced in the pituitary gland during and after pregnancy. Its excess may further lead to the galactorrhea and menstruation disorders in females, and hypogonadism and fertility disorders in males. The most common symptoms associated with both genders include lowered sex drive, sexual malfunctions, headaches or vision disorders. In majority of incidents, hyperprolactinaemia is caused by a pituitary gland tumor, polycystic ovary syndrome, reduced dopamine levels or hypothyroidism. Usual treatment methods involve dopamine agonists intake or surgery.
Luteotropic hormone, simply known as prolactin, is a hormone primarily responsible for milk production (lactation). Normal levels of prolactin in blood is lower than 500 mIU/L in females and lower than 450 mIU/L in males. High levels of this hormone are naturally present during pregnancy and lactation cycle or after meal and sleep. Hyperprolactinaemia is a prolonged high level of prolactin, do not associated with aforementioned processes. It might lead to galactorrhea or menstruation disorders in females, and fertility disorders, hypogonadism or erectile dysfunctions in males. What is interesting, some studies show higher prevalence of hyperprolactinaemia in women.
In majority of the cases, high levels of prolactin are caused by prolactinoma. Prolactinoma is a benign (non-cancerous) tumor located in the pituitary gland, which is responsible for almost half of the incidents. Another possible cause include hypothyroidism, since this condition boost up thyrotrophin-releasing hormone (TRH), which further increases prolactin secretion. Apart from those examples, hyperprolactinaemia may appear as a consequence of prolonged stress, polycystic ovary syndrome, hypothalamus tumor or certain medications.
Symptoms and signs associated with males include:
- Decreased sex drive (libido)
- Erectile dysfunction
- Fertility disorders
- Sexual malfunctions
Whereas symptoms in females include:
- Fertility disorders
- Menstruation abnormalities, or total absence of cycle
- Breast milk production (excluding pregnancy and nursing, during which it is natural)
- Breast pain
- Decreased libido
- Vagina dryness
In addition, headache and vision disorders may somtetimes appear in both sexes, if the disease is caused by the pituitary tumor.
Diagnosis and treatment
Diagnosis is usually based on prolactin blood levels tests. In most cases, one approach will identify this condition. However, if the test is stressful or painful for the patient, it might actually elevate prolactin level, thus 2 or 3 approaches are occasionally needed. Healthcare providers may also perform imaging (MRI or CT) in order to reveal the tumor located inside pituitary, hypothalamus or surrounding tissues. Certain medications can elevate prolactin levels as well, therefore a specialist might ask about ongoing drug therapy. Obviously, in case of females, pregnancy or nursing naturally results in hyperprolactinaemia and it is considered as a non-pathological state.
Treatment main tasks is to eliminate the tumor and to restore gland functionality. It often involves dopamine agonists intake, such as bromocriptine, cabergoline, quinagolide (norprolac) or lisuride. Dopamine agonists are decreasing prolactin production and are able to reduce the tumor.
Hyperprolactinaemia is fairly easy to control. In case of pituitary tumor, over 90% of the incidents are either stable or are disappearing gradually. However, treatment course should be long-term, since this type of endocrine disorder has high recurrence rate.