Why the menstrual cycle can affect sleep

One of the hormonal processes that can affect the quality of women's sleep.

During the menstrual cycle, many cyclical changes take place, both in hormones and in body temperature and metabolic activity.The menstrual cycle is a time of hormonal changes, both in hormones and in body temperature and metabolic activity. Because of these changes and their effects on circadian rhythms, it is believed that the menstrual cycle can significantly affect sleep.

The latter can translate into difficulty falling asleep and staying asleep; or it can manifest itself in the opposite way: an excessive need for sleep. For example, there are those who report the need to sleep more than 10 hours during the menstrual cycle, and in contrast, there are those who report insomnia during some specific days.

According to some studies, these sleep disturbances may be due to different factors associated with the physiological changes of the menstrual cycle. In this article we will review some of these factors, as well as the general functioning of both sleep and menstruation, so that we can better understand how they work.so that we can better understand their relationship.

Circadian cycle and menstrual cycle.

Our whole organism works in cycles. We have, for example, circadian cycles, which are those that last about 24 hours. That is why they are called "circa", which means "around"; and "diano", which means "day".

Part of what circadian cycles regulate is wakefulness and sleep.. This regulation occurs through two biological rhythms that we call internal synchronizers (such as hormonal rhythms, Blood pressure, body temperature, in the metabolic system); and external synchronizers, such as light and darkness, noise, events that cause stress, among others.

When the time of rest and sleep approaches, these synchronizers adapt to our need for rest, that is, they prepare the organism for the decrease in energy that we require when we sleep deeply. Thus, our physiology produces a whole series of functions during wakefulness, and others during sleep, in coordination with external stimuli.

On the other hand, we have infradian cycles, which are those that last more than 24 hours. These cycles are those that regulate physiological events that occur less than once a day, such as the menstrual cycle, which occurs every 28 days.which occurs every 28 days.

How does the menstrual cycle work?

During the menstrual cycle interaction of hormones from the hypothalamus, the pituitary gland and also from the ovaries.. This system is known as the hypothalamic-pituitary-ovarian system (HHO) and is activated by the secretion of different hormones, such as gonadotropins (GnRH), luteinizing hormone (LH) and follicle stimulating hormone (FSH).

From this secretion, the menstrual cycle is divided into two phases: the follicular phase (where FSH is secreted to start releasing the eggs and the necessary hormones); and the luteal phase (which is when the hormone secretion decreases around day 23 of the cycle, causing vascular transformations in the endometrium and finally its detachment, i.e., menstruation).

It is precisely the luteal phase that has been related to the appearance of a series of somatic and physical changes characteristic of the menstrual cycle, among which are sleep cycle alterations.

Sleep disturbances and menstrual cycle

A normal sleep cycle is one that is divided into two distinct states; one is Non-REM sleep (characterized by slow-wave eye movements), and the other is REM sleep (characterized by rapid-wave movements).

In the latter, brain activity occurs at a higher speedwhich requires a series of important hormonal changes. For example, growth hormone, prolactin (which stimulates the production of breast milk), testosterone, melatonin (which helps regulate the circadian rhythm related to light and darkness), and some others that play an important role in menstruation are secreted.

For example, decreased melatonin secretion a decrease in melatonin secretion has been associated with various premenstrual stresseswhich significantly modifies circadian cycles related to light and darkness.

Endocrine activity during sleep and related symptoms

As we have seen, one of the internal factors involved in the regulation of sleep cycles, is endocrine activity (that of the system responsible for releasing hormones within our body).

When the activity of this system is intensified, for example, during the luteal phase of the menstrual cycle, our sleep may also be modified. In addition, the hormones GnRH, LH and FSH, have an important peak of release in the non-REM sleep phase, which means that their concentration levels increase according to specific periods of the sleep cycle.

The latter has been associated particularly with women who have premenstrual syndrome accompanied by affective symptomsand also in women who have a psychiatric diagnosis related to mood.

In other words, some studies on the subject suggest that significant changes in sleep quality during the menstrual cycle occur more frequently in women who have mood disorders, while women without these negative affect symptoms do not usually present significant changes in sleep quality.

Similarly, some studies suggest that although many women are likely to experience sleep disturbances in the luteal phase of the menstrual cycle, it is those women with other more severe premenstrual symptoms who are more likely to experience disturbances in this phase, specifically daytime sleepiness.

Bibliographic references:

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• Adresic, E., Palacios, E., Palacios, F. et al (2006). Premenstrual Syndrome (PMS) and Premenstrual Dysphoric Disorder (PMDD): A retrospective study of prevalence and associated factors in 305 university students. Latin American Journal of Psychiatry, 5: 16-22.
• Baker, F. and Driver, H. (2006). Circadian rhythms, sleep, and the menstrual cycle. Sleep medicine, 8(6): 613-622.
• Manber, R. and Bootzin, R. (1997). Sleep and the menstrual cycle. Health Psychology, 16(3): 209-214.
• Driver, H., Dijk, D.J., Biedermann, K., et al (1996). Sleep and the sleep electroencephalogram across the menstrual cycle in young healthy women. The Journal of Clinical Endocrinology & Metabolism, 81(2): 728-735.
• Lee, K., Shaver, J., Giblin, E. C. et al (1990). Sleep patterns related to menstrual cycle phase and premenstrual affective symptoms. Sleep: Journal of Sleep Research & Sleep Medicine, 13(5): 403-409.