Melatonin What we need to know

02.10.2024

Melatonin is a hormone produced by the pineal gland in the brain. It participates in the regulation of sleep-wake and circadian rhythms. All the functions of melatonin in the body are not fully understood.

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Circadian rhythms are physical, mental, and behavioral changes that occur over a 24-hour period. The most pronounced phenomenon of the circadian rhythm is the alternation of sleep and wakefulness. The sleep-wake process is the body's response to the alternation of light and darkness. The production of melatonin by the pineal gland is activated at night and is minimal during the day.

There is also synthesized melatonin, which is supplied to the body as a nutritional supplement.

How does melatonin affect the body?

The full mechanism of melatonin's effects is still unknown. Its main effect is manifested by affecting circadian rhythms and the sleep-wake cycle.

During the day, the level of melatonin secreted in the blood is minimal, and at night it reaches its peak.

It is believed that a high concentration of melatonin in the blood is necessary for good quality sleep. When the daylight decreases, as soon as the pineal gland receives a signal from the retina about the change of light-darkness (day-night cycle), it starts to produce melatonin. Blind people who cannot perceive light usually have disrupted melatonin cycles and circadian rhythms.

Other effects of natural melatonin

Melatonin interacts with female sex hormones. According to studies, it helps to regulate the menstrual cycle. Melatonin protects neurons from degenerative processes such as Alzheimer's disease and Parkinson's disease. People who have had their epiphysis surgically removed have a faster aging process.

Normal melatonin concentration

The concentration of melatonin can be determined in various biological fluids - blood, urine and saliva, although blood is the main material for its investigation.

Natural melatonin levels significantly depend on a person's gender and age. Newborn babies do not produce their own melatonin. While in the womb, the necessary dose of melatonin is taken from the placenta. In the first weeks, the baby receives melatonin through breast milk. Melatonin production begins at about 2-3 months of age.

The concentration of melatonin in the child's body increases with age and reaches its maximum at the age of puberty. From this period to about 20 years, the concentration of melatonin decreases steadily at a slow rate. After puberty, melatonin concentrations remain higher in females than in males.

The concentration of melatonin remains stable until about the age of 40, after which it begins to decrease. In the elderly over the age of 90, the concentration of melatonin is 5 times lower than in youth.

Decline in melatonin secretion with age is associated with many factors, including calcification of the pineal gland, visual disturbances (eg, cataracts), and others.

There are two main conditions associated with melatonin:

Hypomelatoninemia (decreased level of melatonin compared to normal)
Hypermelatoninemia (increase in melatonin concentration compared to normal).

Both options have their own causes and consequences.

Decreased melatonin levels

Hypomelatoninemia affects human circadian rhythm sleep disorders:

sleep Phase delay disorder - At this time, a person wakes up 2 hours later than during a normal sleep-hepatic cycle.
A sharp disturbance of the sleep phase - Man falls asleep in the evening between 06:00 and 09:00 and wakes up in the morning between 02:00 and 05:00.
Irregular sleep-wake rhythm - In this state, the hours of falling asleep and waking up are not clearly defined. A person sleeps several times during the day and night.
Non-24-hour sleep-wake syndrome -Human sleep-wake times are not synchronized on a 24-hour basis. Sleep and wake times are constantly changing.

These variations of sleep disorders lead to chronic lack of sleep, quality deterioration, which in turn gives rise to other pathophysiological processes:

Arterial hypertension
insulin resistance
Obesity
Metabolic syndrome
Increased risk of breast and prostate cancer
Increased risk of type 2 diabetes

Depending on the causes, hypomelatoninemia (melatonin level decrease) may be primary or secondary: primary hypomelatoninemia develops as a result of direct damage to the pineal gland, for example, during trauma or cancer.

Secondary hypomelatoninemia is the result of exposure to environmental factors and/or medications:

Work in shifts
increasing age
Neurodegenerative diseases: Alzheimer's and Parkinson's diseases
beta-blockers
Calcium channel blockers
ACE inhibitors

Increase in melatonin levels

Hypermelatoninemia is excessively high concentrations of melatonin during the night, during peak secretion. One of the causes is the excessive intake of melatonin, in the form of a supplement. A critical increase in biological (produced) melatonin concentration is very rare.

Hypomelatoninemia can be accompanied by the following pathologies:

Hypogonadism – lack of sex hormones (pathological processes of the pituitary or hypothalamus)
Anorexia nervosa – eating disorder, calorie restriction, fear of weight gain
Polycystic ovary syndrome – a pathology caused by the production of excessive male hormones by the ovary
Spontaneous hypothermia and hyperhidrosis (unexplained decrease in body temperature and excessive sweating)
Rebson-Mendenhall syndrome – pronounced insulin resistance. What follows is an increase in the size of the epiphysis.

Symptoms of hypermelatoninemia are:

Drowsiness during the day
Decrease in body temperature
Dizziness
Decreased muscle tone (hypotonia)

Should we take melatonin as a supplement?

Studies show that supplemental melatonin improves sleep patterns in certain cases, but not always. Before taking melatonin as a supplement, it is better to consult a specialist and determine its level in the blood to avoid possible side effects.

Despite the role of melatonin, many other factors affect the process of falling asleep, such as: caffeine, alcohol, certain medications, mood disorders, depression, anxiety, bed and bedroom characteristics, noise level, and others.

We must take into account that melatonin is not a "magic pill" that will help all sleep disorders. A specialist's decision is necessary to prescribe melatonin as a supplement.

Laboratory "Synevo" We offer the determination of the following hormones: