Is it true that women suffer from sleep disorders more often than men?
Text: Karina Sembe
About the problems associated with sleep, they say more and more: Modern people are not getting enough sleep and, fully aware of the importance of night rest, they are looking for new technological ways to improve its quality - from smart beds with sleep trackers to special bedding sprays. But there are problems that are difficult to solve with the help of an ear plug or a mobile application. According to the United States National Sleep Organization (yes, there is the - The National Sleep Foundation), women are much more likely than men to have insomnia and other sleep disorders. Scientists have discovered and are actively exploring new factors that may be the cause of this disappointing statistics.
There is reason to believe that it is all about the difference in circadian rhythms, and they, in turn, depend on the level of various hormones, including sex hormones. To understand what it is about, you need to take into account that the circadian rhythm is not just an "internal clock" that determines the time of sleep and awakening. Many other physiological processes, such as the regulation of body temperature, occur within this cycle, equal to about twenty-four hours and also known as the biological day. Changes in sleep and wakefulness, fluctuations in body temperature and other vital functions are triggered by environmental signals - from sunlight to atmospheric pressure - and a number of chemical elements in the body.
To find out how different people react to these signals during the day, last year, American scientists decided to study the sleep mechanisms of fifteen men and eleven women (eight of them participated in the experiment during two different phases of the menstrual cycle). The subjects were asked to fall asleep under carefully controlled conditions for three days. In addition, during the study, members of the group were shown daytime sleep. Scientists regularly measured the subjects' body temperature, the quality of their sleep, the level of melatonin, a hormone responsible for circadian rhythms, and how quickly the members of the group fell asleep and how vigorous they were after waking up. The results of the study were unexpected: although the male and female organisms experienced the same physiological processes during the day due to circadian rhythms, in women these cycles proceeded more quickly. Women went to bed and woke up earlier. “In the afternoon, women went to bed on average two hours earlier than men,” explains Dr. Diana Boivin, who conducted the study. “As if the system of daily rhythms in women is one time zone east than in men.”
Of course, to confirm the results will require a sample much wider. However, the data from this study are quite consistent with the earlier one, which showed that the biological day shorter than twenty-four hours is more common among women. In addition, they have more cases of physical exhaustion after being awake at night. The fact that women often wake up earlier than men, scientists explain the changes in hormone levels and body temperature within the daily rhythm. The difference in their duration, as well as physiological fluctuations within the cycle, are considered to be quite normal and most of us do not cause any complications. At the same time, such scientific observations bring us closer to an understanding of why failures in the “biological clock” and sleep disorders are more characteristic of women.
Circadian rhythms affect not only sleep, but also processes such as, for example, the body's response to different types of medications.
Although a direct link between the participants' menstrual cycles and the quality of their sleep was not found in the above tests, another small study by the same laboratory showed that during the luteal phase of the cycle, that is, between ovulation and menstruation, the total amount of sleep in the fast phase may decrease. Now scientists believe that the phenomenon may be associated with the work of the suprachiasmatic nucleus - a small cluster of neurons in the brain that controls circadian rhythms. This zone regulates the level of production of hormones that determine the mechanisms of sleep and awakening, in particular melatonin. It turned out that estrogen receptors are also located in this nucleus, and it is known to regulate the flow of the menstrual cycle and all accompanying changes in the body, including body temperature, an important factor in the sleep-wake system.
On the basis of these observations, researchers conclude about another type of connection between the level of hormones and our "internal clock." Dr. Boywin quite boldly states: "In essence, the brain area responsible for the circadian rhythm and sleep mechanisms has gender." Another somnologist, Dianne Augelli, is more cautious in expressions in an interview with New York Magazine, but also confirms the role of sex hormones in the formation of circadian rhythms: "Estrogen works as a neurotransmitter in different directions, some of which affect the quality of sleep, and progesterone can show sleepy properties ". This factor, according to physicians, is of fundamental importance, because daily rhythms affect not only sleep, but also processes such as, for example, the body's response to different types of drugs.
There are more obvious and thoroughly studied factors that form the statistics of sleep disorders. In women, for example, pregnancy and menopause. In addition to changes in estrogen and progesterone levels, general physical discomfort can be observed during pregnancy, as well as characteristic symptoms - from burning in the chest to restless legs syndrome, which affects the quality of sleep. Sleeplessness and sleep apnea (temporary stop or weakening of breathing) are frequent companions of pregnancy and menopause. During the latter, it is also known that there are regular attacks of heat and excessive sweating, including at night. In addition, a number of studies prove that women suffer anxiety more acutely than men and more severely perceive stress in their professional and personal lives — quite a lot of research has been said to affect the stress hormone cortisol on sleep disorders.
In any case, scientists have only recently approached an understanding of how complex sleep mechanisms actually work and in which cases sex differences do matter. In existing studies, proving the relationship of the level of sex hormones and the duration of daily rhythms, involved an insufficient number of subjects. In addition, participants in such experiments, as a rule, are either completely healthy or one and all suffer from sleep disorders, so proper distribution of data is difficult to achieve. Nevertheless, researchers already confidently associate the difference in circadian rhythms and the level of sex hormones with the fact that sleep disorders are more pronounced in women - in particular, they sleep worse in the morning. How exactly this pattern arises remains to be seen.
Photo: Africa Studio - stock.adobe.com, elizabeth W