World Sleep Day | Academician Lu Lin: Good sleep is the source of health

Lu Lin

In recent years, with the increasing pressure of life and work, the incidence of sleep disorders has increased, and the public's demand for good sleep has become increasingly urgent. March 21 is World Sleep Day, and this year's theme is "Good sleep, the source of health." This magazine specially invited Professor Lu Lin, an academician of the Chinese Academy of Sciences and the incoming chairman of the Psychiatry Branch of the Chinese Medical Association, to interview, hoping to draw people's attention to the importance of sleep; at the same time, to explore the research hotspots of sleep medicine, in order to help the development of the discipline.

In modern society, more and more people are suffering from insufficient sleep and poor sleep quality, but people often cannot tell whether they have sleep disorders, or ignore the disease or pay too much attention to it. So, when should people be vigilant and seek medical help?

Common sleep disorders include insomnia, sleep apnea, excessive sleepiness, circadian rhythm disorders, and parasomnias. Insomnia is the most common sleep disorder, which refers to the difficulty in starting and maintaining sleep, including difficulty falling asleep, shallow sleep, dreaming and waking up early, or still feeling tired after waking up.

We don’t need to worry too much about occasional insomnia, but if it is severe or lasts for a long time, it will have a serious impact on our physical and mental health, and we need to seek medical attention in time. Sleep apnea is also common, and the most typical symptoms of this disease are snoring and apnea.

Many people think that snoring is a sign of good sleep or a normal phenomenon, but from a medical perspective, snoring is a manifestation of obstructed breathing during sleep, which can cause hypoxia of tissues and organs and cause great harm to the body. There is also evidence that patients with sleep apnea may experience daytime sleepiness or headaches, difficulty concentrating and other symptoms. It is worth noting that it is difficult for the patient to detect it himself, and it is often discovered by his bed partner or cohabitant.

Among sleep disorders, sleepiness is a typical symptom of many diseases, such as insomnia and sleep-related breathing disorders mentioned above. Sleepiness is manifested as irresistible drowsiness or even sudden falling asleep during the main period of the day. In severe cases, cataplexy may occur.

In addition, some abnormal behaviors during sleep are also worthy of attention. For example, sleepwalking and suddenly shouting during sleep are also important "signals" of sleep disorders. We need to pay special attention to them and seek medical treatment in time.

Sleep disorders often cause diseases in various systems. Could you please briefly introduce the dangers of sleep disorders?

The harm of sleep disorders is mainly reflected in three aspects: physical diseases, mental diseases and impaired cognitive function. Sleep is associated with many physical diseases. Sleep fragmentation accelerates atherosclerotic lesions. Sleep disorders are related to the onset and course of coronary heart disease, heart failure, stroke and atrial fibrillation. A study involving 400,000 people found that sleep duration was negatively correlated with hypertension, atrial fibrillation, pulmonary embolism and chronic ischemic heart disease within a certain range, suggesting that too short sleep duration (≤6 h) is a potential risk factor for hypertension, atrial fibrillation, pulmonary embolism and chronic ischemic heart disease. The latest meta-analysis results show that the incidence of sleep disorders in patients with type 2 diabetes is 40%. Too long or too short sleep time and other sleep disorders may increase the risk of diabetes, and some symptoms of diabetes will affect the patient's sleep quality, forming a vicious circle. A six-year follow-up of 130,000 Parkinson's patients found that the risk of Parkinson's disease in patients with restless legs syndrome was 4.19 times that of ordinary people, and the risk of Parkinson's disease in patients with sleep apnea was 1.45 times that of ordinary people.

In terms of mental illness, sleep disorders are a major factor in mental health problems. Long-term lack of sleep will increase the risk of mental illnesses such as depression. Improving sleep is beneficial to mental health. For example, after insomnia is treated, the symptoms of mental illness such as hallucinations, paranoia, anxiety, depression, nightmares, etc. are alleviated.

In terms of cognitive function, lack of sleep impairs brain function, including changes in memory, attention, and reward-related brain functions. Sleep disorders increase the risk of dementia, aggravate cognitive impairment, and induce neuroinflammatory responses. In addition, lack of sleep may damage prefrontal lobe activity, hinder emotional regulation, and have a significant impact on cognitive function during wakefulness.

Sleep disorders are often caused by the combined effects of internal and external factors. How can we avoid external factors and adjust internal factors to get a good sleep?

Sleep is greatly affected by social and psychological factors. Good personal psychological and physical condition, suitable sleeping environment, and necessary sleep knowledge are all important prerequisites for getting a good sleep.

On the one hand, we must have a clear understanding of our own mental state. When we are under high stress, depression, or other emotional states, we should use reasonable methods to adjust our emotions. If necessary, we can seek help from professionals to alleviate our psychological problems.

At the same time, it is also essential to create a suitable sleeping environment. Try to avoid light and noise in the room when sleeping, choose bedding with appropriate softness, and minimize the use of electronic devices before going to bed.

Not only that, we should also have a correct understanding of sleep knowledge and get rid of some "misunderstandings": making up for sleep cannot make up for the damage caused to our body by staying up late, but will disrupt our normal sleep rhythm. No matter how long we slept the night before, try to get up at a basically fixed time, don't stay in bed or take a nap; establish a strong connection between the bedroom/bed and sleep, and go to bed only when you feel obviously sleepy; avoid excessive stimulation before going to bed, and reduce high-intensity mental and physical activities; many people think that drinking can help you fall asleep, but in fact drinking will disrupt the original sleep rhythm, shorten sleep time, and have a negative impact on sleep.

The Healthy China Action (2019-2030) emphasizes the importance of healthy sleep in many special actions, such as the mental health promotion action and the primary and secondary school health promotion action. Could you please briefly introduce the important role of healthy sleep in promoting a healthy China?

Healthy sleep is very necessary and timely for a healthy China. Chinese residents have serious sleep problems, and the incidence of sleep disorders continues to rise and is younger: among the elderly population over 60 years old in my country, the incidence of sleep problems is about 35.9%, and the incidence of sleep problems among Chinese teenagers is 26%; the statistics of the "2022 China National Healthy Sleep White Paper" show that nearly 3/4 of the respondents have had sleep problems. Sleep disorders not only have a negative impact on health, but also cause serious social burdens.

According to statistics, the direct and indirect medical expenses caused by sleep problems in Australia in 2019-2020 reached 35.4 billion US dollars (about 13.1 billion US dollars for sleep apnea, 13.3 billion US dollars for insomnia, and about 9 billion US dollars for restless legs syndrome).

For a long time, the public has had a deep misunderstanding of some sleep knowledge. The public does not know what a good sleep is and how to get a good sleep. Therefore, it is of great significance to carry out popular science on healthy sleep knowledge, improve the level of sleep knowledge among the whole people, and reduce the incidence of sleep disorders in my country.

You have been deeply involved in the field of sleep medicine for many years. What are the current research hotspots in the field of sleep medicine? What challenges are you facing? What do you think are the future development directions of sleep medicine?

Science once proposed the 125 most challenging scientific questions, and "Why do humans need to sleep" was selected among them. This also shows that sleep is a basic life behavior of human beings, and "why does it happen", "how does it happen" and "what happens" are the most important and challenging issues discussed in the field of sleep medicine.

In addition, as a clinician, the treatment of sleep disorders is also an important scientific issue in the field of sleep medicine. In terms of drug treatment, increasing drug efficacy and reducing adverse drug reactions are still the focus of clinical attention; in non-drug treatment methods, breakthroughs in existing physical treatment methods and research on psychological treatments still need to be deepened.

In terms of scientific research, the establishment of a standardized database in the field of sleep medicine will also provide us with better resources for understanding sleep disorders. Given the complexity of the content covered by sleep medicine, in the future, the development of sleep medicine cannot be done behind closed doors. It is necessary to communicate more with other professions and disciplines. Multiple disciplines should provide new ideas and methods for sleep medicine from their own perspectives, work together to deeply understand the mechanism of sleep occurrence and development, and provide better medical services for patients.

Text | Zuo Shuying, Zhang Zhibo, Yan Wei