Preliminary Clinical Reports Supporting a Possible Correlation between
Untreated, a prolactinoma can cause: Reduced hormone production if the tumor presses on the pituitary gland, which may lead to symptoms such as weight loss or fatigue.
Symptoms of high prolactin levels include irregular periods, loss of sex drive, sexual dysfunction, heavy menstrual bleeding, weight gain, anxiety, depression, and psychosis.
These findings suggest that normal prolactin levels may serve as a regulatory mechanism, favoring energy metabolism in the obese state (67, 68). Prolactin is also involved in metabolism through its effect on adiponectin, a hormone secreted by adipose tissue.
Excess prolactin can cause the production of breast milk in men and in women who are not pregnant or breastfeeding. In women, too much prolactin can also cause menstrual problems and infertility (the inability to get pregnant). In men, it can lead to lower sex drive and erectile dysfunction (ED).
In contrast, clinical studies in humans have indicated a correlation between high PRL levels and psychological distress. Female patients with hyperprolactinemia usually report more symptoms of anxiety and hostility than control female subjects (24).
Left untreated, a prolactinoma may grow large enough to press on your optic nerve. This nerve sits near the pituitary gland. The nerve sends images from your eye to your brain so that you can see. The first sign of pressure on the optic nerve is a loss of your side (peripheral) vision.
Higher prolactin has also been associated with the risk of developing psychosis [29], and with specific psychological symptoms of anxiety, hostility, somatization [21,44].
Plasma prolactin is higher in major depressive disorder and females, and associated with anxiety, hostility, somatization, psychotic symptoms and heart rate - PMC.
Memory impairments are frequently reported with hyperprolactinemia including decline in short-term memory, verbal or non-verbal memory (4, 21). Consistently, we found that patients with prolactinomas showed a sharply decreased GMV in left hippocampus that was correlated to verbal memory deficits.
Hyperprolactinemia results in impaired body composition with greater waist circumference, body weight and BMI, and increased body fat percentages only in men.
There is some evidence that functional hyperprolactinemia may be due to stress-induced neuroendocrine changes of dopamine and serotonin, thus affecting prolactin release [35]. REM sleep rebound, a behavioral coping mechanism to stress, has been found to be mediated by prolactin [36].
It can also lead to irregular or missed periods. Some women have high prolactin levels without any symptoms. In men, high prolactin levels can cause galactorrhea, impotence (inability to have an erection during sex), reduced desire for sex, and infertility.
Patients with hyperprolactinemia often present with emotional difficulties. These occasionally persist even after successful treatment.
Health conditions other than a prolactinoma that may increase prolactin levels in your blood include: Hypothyroidism (underactive thyroid). Kidney disease. Shingles, especially if the rash or blisters are on your chest.
In women, physical or psychological stress, pregnancy and nipple stimulation have all been found to increase prolactin levels. In both women and men, chronic kidney disease and hypothyroidism (when your thyroid gland does not make enough thyroid hormone) can also lead to elevated prolactin levels.
In mammals, prolactin is associated with learning, stimulation of the immune response, reduction of body temperature and increased corticosterone secretion. It is involved in the behavioural aspect of reproduction.
High levels of prolactin can also result in weight gain and neuropsychological disturbances.
Prolactin signals a woman's breasts to produce milk during pregnancy and breastfeeding. Having too much prolactin in the blood, a condition called hyperprolactinemia, can cause infertility link and other problems. In most cases, prolactinomas and related health problems can be successfully treated with medicines.
Prolactin levels are usually directly proportionate to the size of the tumor, ranging from below 200 ng/ml with less than 1 cm, 200 ng/ml to 1000 ng/ml with 1 cm to 2 cm, and more than 1000 ng/ml with tumor sized more than 2 cm in diameter.
Oral medications known as dopamine agonists are generally used to treat a prolactinoma. These drugs mimic the effects of dopamine — the brain chemical that controls how much prolactin is made. Dopamine agonists can decrease the production of prolactin and shrink the size of the tumor.
Although we initially hypothesized that prolactin might induce maternal aggression, our data have revealed a role for this hormone in restraining aggressive behavior.
An MRI may be recommended to determine if the prolactinoma has grown. If so, bromocriptine or cabergoline is usually recommended to decrease the size.
The hormone prolactin is necessary for the production of breast milk, but it also affects adipose (fatty) tissue and the body's metabolism. Raised prolactin levels in a woman who is not pregnant or breast feeding reduces lipid (fat) metabolism.