The meaning of sleep
Healthy sleep is one of the main components of a healthy life.
Although sleep may seem like a completely inactive phase of life, physiologically it is a period of intense activity, when various so-called neurotransmitter substances begin to act and help the body:
- To be re-energized
- Renew tissues
- Process the flow of information received during the day in memory
- Let the growth processes take place.
Bedtime
Our bodies obey an internal biological clock that is routinely synchronized with day and night. Consciousness, metabolism, the sleep-wake cycle, and many other processes function according to this rhythm.
The following participate in its formation:
- External physical factors such as: light, darkness, physical activity, nutrition;
- Internal biological factors, such as: neural and hormonal signals in the brain.
Before artificial light became available to humanity, people for centuries went to sleep at sunset and woke up at sunrise. It is this high sensitivity to light that determines the production of the hormone melatonin. Melatonin is the hormone that is mainly responsible for the process of falling asleep. In particular, daylight causes a delay in the production of melatonin in the brain, and after nightfall, its concentration increases, which leads to sleep.
What is the situation today? Today, our body has lost touch with natural sleep stimulants. After sunset, we spend a period of time in front of various types of screens under artificial light. Unfortunately, both artificial light and the light from the screen block the production of melatonin in the brain and prevent us from falling asleep. Obviously, this also disrupts the biological rhythm formed as a result of evolution, on which many processes in our body are based.
sleep duration
In the modern world, both adults and children sleep for shorter periods of time than before.
How much sleep is enough for the body depends on various factors - the most important of which is age.
The duration of sleep required by the body is:
- In newborns – 14-17 hours/day
- At 12 months old – about 10 hours/night and 4 hours/day
- At 2 years old – about 11-12 hours/night and 1-2 hours/day
- Ages 3-5 – 10-13 hours
- Ages 6-13 – 9-11 hours
- Ages 14-17 – 8-10 hours
- Adults – 7-9 hours
Sleep quality Just as important as the duration of sleep, when the sleep process is frequently interrupted, its quality declines.
Sleep time, sleep duration, and sleep quality are factors whose disruption causes a number of negative changes in the endocrine system and the body as a whole.
The production, concentration in the blood, and effectiveness of many hormones of the endocrine system depend on the rhythm of sleep and wakefulness, such as: cortisol, leptin, ghrelin, insulin. Also prolactin, testosterone, parathyroid hormone, and growth hormone obey biological rhythms and their production is maximal at night.
Sleep and cortisol
Cortisol The main hormone that helps the body cope with any kind of stress. Its release obeys a strictly defined daily rhythm and sleep pattern, namely, the peak is at dawn, its concentration decreases during the day and reaches a minimum before bedtime. Both lack of sleep and disruption of sleep time lead to changes in the rhythm of cortisol production and the accompanying negative consequences for the body.
Sleep and metabolic diseases
The connection between sleep disorders is particularly close With metabolic diseases.
Lack of sleep is already being actively considered as one of the causes of the current obesity epidemic worldwide.
Insufficient sleep causes hormonal imbalances that contribute to obesity. In particular, the concentration of appetite-regulating hormones: leptin and ghrelin changes in such a way that the feeling of hunger increases as a result. There is also a tendency to choose more high-calorie foods during sleep deprivation. Eating high-calorie foods late at night, of course, causes weight gain.
In addition, changes in growth hormone and cortisol levels caused by sleep disruption are also contributing factors to obesity.
Additionally, physical activity levels are reduced, as lack of sleep leads to daytime drowsiness and decreased energy.
In parallel with obesity, there is a very close connection between sleep hygiene and glucose metabolism. Glucose concentration also fluctuates and undergoes physiological changes during the day and night according to internal biological rhythms. It has been established that even one night of sleep disturbance increases insulin resistance, which leads to an increase in blood sugar levels. As a result, sleep disturbances increase the risks of prediabetes and diabetes. The main hormones responsible for these processes here are also insulin, growth hormone, cortisol and non-physiological changes in their concentrations in conditions of sleep disturbance.
Thus, regulating sleep can prevent weight gain or promote weight loss, as well as improve the management of existing diabetes.
General effect on the body
Insufficient sleep over a short period of time causes general weakness, fatigue, memory and learning problems, irritability, and lowers immunity. Over a long period of time, sleep disruption becomes the cause of stress hormone regulation disorders, depression, anxiety, decreased testosterone concentration, and as a result, hypogonadism in men. In addition to increasing the risk of obesity and type 2 diabetes, it also causes cardiovascular diseases and can reduce life expectancy.
Sleep hygiene is especially important for children and adolescents. They need longer and more regular sleep, as important changes and processes are taking place in the body and brain. Sleep is actively involved in the production of growth hormone and sexual development. As a result of sleep disruption, the same hormonal changes occur in this age group as in adults, and the risks of obesity and diabetes are also increased.
How to regulate sleep?
- Try to maintain the same sleep schedule every day.
- Sleeping in for a long time on the weekends can make it difficult to maintain a consistent sleep schedule, so don't oversleep for more than an hour on these days.
- Eating before bed affects sleep quality and increases the risk of obesity and diabetes
- Don't take caffeine before bedtime.
- The light from your phone, tablet, or laptop can reduce melatonin levels and make it harder to fall asleep. Avoid using these devices before bed, and if you must, turn on a night light that minimizes melatonin-suppressing light.
- Try different options for comfortable sleep and choose the one that suits you best. For example: sleep with appropriate lighting; maintain the desired temperature in the bedroom; avoid noise, or vice versa, use sound-emitting devices that are suitable for you (music, nature sounds, etc.)
- Use the bed only for sleeping and avoid eating or working there.
Author: Elga Giorgadze (Doctor Endocrinologist))
Also find out:
- What is insulin resistance?
- Prevention of type 2 diabetes
- The impact of stress on the endocrine system
