Why is World Sleep Day celebrated and what is its purpose?
World Sleep Day is celebrated annually around the time of the spring equinox (autumn in the southern hemisphere) in March, when day and night last about the same length of time. Its purpose is to raise awareness of the importance of good quality and quantity of sleep for proper physical and psychological health, and of the importance of sleep disorders, which are extremely common in the population. In 2022, the chosen slogan is “Quality Sleep, Healthy Mind, Happy World”, aiming to highlight the importance of quality sleep in proper mental health.
What are the most common sleep disorders?
The most common sleep disorder is undoubtedly insomnia. In Spain, it is estimated that between 25-35% of the population suffers occasional insomnia, and between 10-15%, some 4.5-5 million people, chronic insomnia, which lasts more than three months, the really important one. Insomnia is common in children and young people, also, for example, affects 30% of children between 6 months and 5 years of age, and affects between 3 and 12% of adolescents.
The second most common sleep disorder is Sleep Apnea, which affects 6-8% of the general population in Spain (20% in those over 65 years of age) and which has great repercussions on health and quality of life, and of which there are probably still many undiagnosed cases, including the child population.
And the sleep disorder that closes the triad of the most frequent is Restless Legs Syndrome or Willis-Ekbom disease, a very misunderstood disease, which can be very disabling and often complicated in terms of its management. The presence of this disease in Western countries, in the Caucasian population, is estimated at 5 to 10% of the population. If severity criteria are applied, it is estimated that between 2 and 4.6% of the general population suffers from a disease that requires basic drug treatment, at least 2 million people in Spain.
What type of people are more likely to suffer from a sleep disorder?
Insomnia is more frequent in women, people with medical illnesses and/or psychological-psychiatric disorders. It tends to increase its presence with age, this is due to sleep disturbance as we get older, due to more or less physiological causes, to the increased use of medications and to the association with medical pathologies.
Sleep apnea is more frequent in men, and it is clearly more frequent in overweight people, especially, but not only, if the overweight is important. It should be noted that it is present, for example, in 60-70% of those affected by treatment-resistant arterial hypertension, and may in most cases be the cause of such resistance to treatment. In children, it is much more frequent when there are obstructive upper respiratory tract problems, especially large tonsils.
Restless legs syndrome is twice as frequent in women in adulthood, probably due to the implication of deficient iron metabolism in the disease (monthly blood loss in women of childbearing age), and 6-7 times more frequent in people who have first-degree relatives with the disease, it has a clear genetic component.
Certain parasomnias (sleepwalking, night terrors, confusional awakenings) are much more frequent in infantile ages, they can be very dramatic, but are generally benign and improve with age.
And finally, excessive consumption of alcohol, caffeine, certain medications and drugs (including cannabis, which is falsely perceived to improve sleep) are clearly conducive to the onset of all types of sleep disorders.
Why is it so important to sleep well?
There are already several known reasons that disprove that sleep is only an inactive period of simple rest; on the contrary, it is an active period with various physiological functions, probably some of which have yet to be discovered. Among those currently known are:
- At the level of psychic performance and mental health: it is now known that effective sleep deprivation worsens productivity, concentration and cognitive ability. It has also been shown that children’s sleep patterns can have a direct effect on their school performance and behavior.
Sleep also plays an important role in the processing and consolidation of memory storage, activities mostly performed when we sleep. On the other hand, there are recent data that the elimination of toxic wastes for the brain is largely performed during the deep sleep phase, and its chronic disturbance seems to predispose to a higher risk of neurodegenerative processes, such as Alzheimer’s disease.
Mental health problems, such as depression, have a strong bidirectional link with poor sleep quality, both reinforcing each other. There is even a clear relationship between poor sleep quality and a high suicide rate. - Relationship with obesity and metabolic disorders: Currently, poor quality of effective sleep is considered to be one of the most potent risk factors for obesity, with an estimated risk of between 55% and 89%. In addition, it is known that adequate sleep is necessary for tissue rejuvenation, restoration and repair, muscle growth and the proper release of various hormones. Poor sleep quality is also linked to the propensity for diabetes.
- Relationship to cardiovascular health: a clear relationship has been found between significant sleep disturbances and increased incidence of high blood pressure, cardiac arrhythmias and cardiovascular (and possibly cerebrovascular) disease.
Adequate sleep improves immune function, defenses, and contributes to better and earlier recovery from illness. As an example, it has been found that people who sleep less than 7 hours have a risk of colds about three times higher than those who sleep at least 8 hours. On the other hand, a relationship has recently been established between some disorders of the quality and quantity of sleep and the predisposition to suffer from various types of cancerous diseases. In hospitalized patients, the protocols for improving sleep quality are reflected in a better and faster recovery from the processes that have required such hospitalization, including the prognostic improvement of patients admitted to the ICU.
In summary, the adequate quantity and quality of effective sleep has joined the correct diet and the practice of physical exercise as another essential pillar for health and quality of life.
How has the crisis generated by COVID-19 affected the quality of sleep in the population?
The COVID-19 pandemic has generated in a large part of the population a state of post-traumatic stress and mood alteration, secondary to health, economic, work, family and change of situation concerns, living in closed environments. In these situations, one of the first things that may appear is poor sleep quality, in the form of insomnia and increased nightmare disorder. This circumstance is being prolonged by the situation of economic uncertainty that has arisen in the post-pandemic period, aggravated by the war situation in Europe. Consultations for problems of insomnia and poor quality of sleep are increasing considerably in the first months of the year 2022, in relation to a worrying repercussion of the same in the quality of life of those affected.
During the pandemic, especially during periods of confinement, an improvement in the quality of sleep has also been found in part of the population. This seems to be due to improvement of life habits, sleep hygiene and daily, personal and work stress during confinement, in families or persons little affected by the health circumstances and the problems of coexistence in closed spaces, or with less worries at the level of economic and work repercussions that could be caused by the confinement situation.