Adequate sleep, a balanced diet and appropriate exercise are three internationally recognized health standards. However, in modern life, the phenomenon of insufficient sleep caused by heavy work pressure and poor living habits is very common. According to the newly released "China Sleep Research Report (2022)", in the past 10 years, Chinese people have fallen asleep more than two hours late, and the average sleep duration has shrunk from 8.5 hours in 2012 to 7.06 hours in 2021. The survey shows that only 35% of Chinese people can sleep enough for 8 hours, and new mothers, students, and professionals have prominent sleep problems.
According to the sleep survey report released by the "Chinese Sleep Research Society", more than 300 million people in the mainland have sleep disorders, the incidence of insomnia in adults is as high as 38.2%, and more than 90% of primary school students sleep for a long time that does not meet the standard; more than 3/4 of adults fall asleep after 11 pm, and nearly 1/3 of people stay up until after 1 a.m. to fall asleep. Especially in the past year, due to the impact of the new crown pneumonia epidemic, people have spent more time at home, but the overall sleep time has been delayed by 2 to 3 hours, and the number of searches for sleep problems has increased by 43%, and the above data is still increasing year by year [1].
Among the many diseases, common diseases caused by lack of sleep are hypertension, diabetes, obesity, heart disease, colds, etc. have also attracted people's daily attention and attention. Numerous recent studies in academia have found that long-term sleep deprivation is harmful to the body far more than that. Whether it is "active staying up late" or "passive insomnia", it will cause harm to the human body, and we should understand this well.
JACC: Lack of sleep for 14 days
11% increase in visceral fat
In the conventional consciousness, everyone will feel that people who eat more and sleep more are prone to gain weight, but the relationship between sleep and obesity is far less simple than everyone thinks. A growing body of research has found that sleep deprivation can lead to weight gain, and the accumulation of abdominal fat can adversely affect organs such as the liver and heart, increasing the risk of disease.
Recently, a study published in the Journal of the American College of Cardiology (JACC) titled "Effect of Sleep Extension on Objectively Assessed Energy Intake Among Adults With Overweight in Real-life Settings: A." Randomized Clinical Trial" randomized cross-controlled clinical trial results (Figure 1) found that sleep deprivation led to a 9 percent increase in total abdominal fat area and a 11 percent increase in abdominal visceral fat, which is strongly associated with the onset of cardiac and metabolic diseases [2]. This is because lack of sleep increases energy intake, while energy expenditure has barely changed, resulting in weight gain, especially a significant increase in the accumulation of visceral fat.
Figure 1 Research results (Source: [2])
Researchers from the Mayo Clinic in the United States conducted an intervention study of 12 healthy participants aged 19-39 years who were not obese, of whom 9 were men. The entire study cycle lasted 21 days and consisted of a 4-day adaptation period, a 14-day trial period, and a 3-day recovery period (Figure 2). During the 4-day adaptation period, all participants slept 9 hours per night; during the 14-day trial period, participants were randomly divided into sleep-restricted and sleep-control groups. The former slept at 4 hours per night, while the latter slept at 9 hours per night; after entering the recovery period, all participants slept 9 hours a night; during the trial, all participants were free to choose food and intake.
Figure 2 Experimental design process (Source: [2])
The researchers regularly measured and measured participants' caloric intake and digestion, weight changes, fat (including visceral fat and abdominal fat) distribution, and appetite-related biomarker levels; after 3 months, all participants were assigned to the opposite group during the trial period for another 21-day trial. After testing and comparing, the researchers found that:
Participants in the sleep-restricted group during the trial period increased their average daily energy intake by 308 Kcal and their intake of protein and fat increased by about 13% and 17%, respectively, compared to the adaptation period;
During the trial, the participants' energy consumption did not show a significant change. This meant that after the participants were restricted to sleep, their energy intake increased, but their energy expenditure did not decrease;
The trial found that although participants gained less weight (only 500 g), there was a significant increase in abdominal fat and visceral fat. After sleep restriction, participants increased their abdominal fat by about 9 percent and their abdominal visceral fat by about 11 percent.
The researchers analyzed that sleep deprivation may affect leptin and ghrelin levels, which in turn increases the appetite of subjects, leading them to choose high-calorie foods. However, more research is needed in the future to explore the relevant mechanisms and determine whether prolonging sleep time can reverse the accumulation of abdominal fat caused by lack of sleep. Nowadays, sleep deprivation is a common phenomenon, and for those who are sleep-deprived, behavioral interventions should be carried out, such as enhancing exercise and maintaining a healthy diet, so as to improve health.
Harvard Medical School: Sleep deprivation
Severe damage to the brains of adolescents
In October 2021, researchers from Harvard Medical School and Boston Children's Hospital found that sleep deprivation can cause devastating damage to the brains of developing adolescents, and even cause problems with memory, attention, and emotions in adolescents [3]. The study was published in Cerebral Cortex Communications titled "Shorter Duration and Lower Quality Sleep Have Widespread Detrimental Effects on Developing Functional Brain Networks in Early Adolescence" (Figure 3).
Figure 3 Research results (Source: [3])
The researchers analyzed 5,566 pieces of sleep and brain imaging data from the Adolescent Brain Cognitive Development Study (ABCD Study) and invited parents of all participants to participate in a child's sleep questionnaire. In addition, the researchers collected data from each adolescent's resting brain through functional magnetic resonance imaging, analyzing the data to identify multiple brain networks that play an important role in cognitive function.
Note: The ABCD Study is the largest long-term study of brain development and child health in the United States.
Research analysis shows that:
Studies have observed abnormal network changes in specific parts of the brain such as multiple cortical regions, the thalamus, basal ganglia, hippocampus, and cerebellum. Such network abnormalities can lead to deficits in a variety of cognitive processes, including attention, reward mechanisms, emotion regulation, memory, and the ability to plan, coordinate, and control actions;
The negative effects of sleep deprivation on the adolescent brain are widespread, involving individual areas of the brain and large circuitry, which in turn can negatively affect sleep quality; shorter sleep durations, longer sleep latency, frequent waking, and sleep-disordered breathing are associated with brain networks with low flexibility and resilience (Figure 4);
The longer the screen, the shorter the sleep time; obesity is associated with shorter sleep duration, increased nocturnal activity, sweating, snoring, difficulty waking up, and daytime sleepiness. Higher household incomes were significantly associated with longer sleep durations.
Figure 4 Lack of sleep, difficulty falling asleep, and variations in snoring frequency (Source: [3])
These findings are of great significance for understanding the cognitive function of adolescent brains, so that the public understands that sleep time and quality will affect the developing brain function circuits, which is conducive to elucidating learning disabilities such as declining academic performance and inattention of adolescents. Good sleep must be a top priority in everyone's life, and even more important for adolescents in development. As a parent, we should pay more attention to the harm that sleep deprivation will do to adolescents and help them develop good sleeping habits.
Bad sleep?
Sleep has found a new mechanism by which sleep affects mood
I believe that we have all had such an experience: the day before the sleep is not good, wake up to see that anything is not beautiful, and even unconsciously will be irritable and escalate, temper a little bit. So how does sleep affect our emotional responses? Scientists have long studied this.
In April 2020, researchers from the University of Pittsburgh School of Medicine and Iowa State University published the study "0276 Does Losing Sleep Unleash Anger?" in the sleep specialist journal Sleep, which explored the mechanism of the effects of sleep deprivation on anger and found that it was confirmed that sleep deprivation increased feelings of anger and frustration [4] (Figure 5).
Figure 5 Research results (Source: [4])
The study included an analysis of diaries and experimental results. In the diary study, the researchers tracked the sleep of 202 college students for a month, analyzing the subjects' daily diaries to count their sleep muzzles, sources of stress, and anger. Preliminary results showed that sleep-deprived subjects showed more anger.
In addition, the team invited 147 community residents to join the experiment and randomly divided it into two groups, one group to maintain normal sleep time, and the other group to sleep only 5 hours for two consecutive nights. During this time, the researchers assessed the participants' levels of anger when exposed to irritating noise. The experiment found that participants who slept well were able to adjust to the noise and also reported lower levels of anger two days later. In contrast, sleep-restricted people showed higher and stronger feelings of anger at disgusting noises. In another related experiment, participants reported feelings of anger after losing a competitive online game and got similar results.
The study shows that lack of sleep can destroy the body's ability to adapt to bad environments, which is prone to bad emotions. The study authors said that the results of the diary analysis study showed that the effects of sleep deprivation on mood are also applicable to daily life, and for people who sleep less, they are more likely to have bad mood in the afternoon. If there is sleep interruption, insomnia, etc., individuals should pay close attention to specific emotional responses and adjust them in time.
PNAS: Sleep deprivation
It damages 711 genes
A study published in The National Academy of Sciences of the United States of America (PNAS) found that sleeping less than six hours a night for a week causes changes in the function of 711 genes in the body, which involve functions such as metabolism, inflammation, immunity, and stress resistance (Figure 6).
Figure 6 Research results (Source: [5])
Researchers from the University of Surrey in the United Kingdom analyzed blood samples from participants and divided them into two groups, one group was a blood sample taken under less than 6 hours of sleep per night for 7 consecutive days, and the other group was a blood sample taken under the condition of sleeping up to 10 hours per night for 7 consecutive days. The results of the study showed that more than 700 genes in the blood were altered for a week of sleep deprivation. Each gene has instructions for building proteins, so those genes that become more active produce more proteins, altering certain chemical processes in the body. Moreover, the natural biological clock can also be disrupted, areas such as the immune system and the body's response to damage and stress will be affected, and some genes spontaneously appear and decline in daily activities, but this effect will still be affected by lack of sleep. In short, sleep is very important for the body to recover and maintain physical function. If we can no longer replenish and replace new cells, then it can lead to degenerative disease.
JBMR: Sleep shortage
Or cause osteoporosis in postmenopausal women
In April 2020, American researchers published a research paper titled "Short Sleep Is Associated With Low Bone Mineral Density and Osteoporosis in the Women's Health Initiative" in the Journal of Bone and Mineral Research. The study found that sleep deprivation affects bone health in women or is associated with low bone mineral density and osteoporosis (Figure 7) [6]. While osteoporosis is known as the "killer of silence", low bone density and osteoporosis fractures are common manifestations of aging and are associated with a higher risk of morbidity and mortality.
Figure 7 Research results (Source: [6])
The study, a study by the Women's Health Initiative (WHI), enrolled 161808 postmenopausal women aged 50-79 years in 40 clinical centers. In subjects, sleep quality was assessed using the WHI Insomnia Rating Scale, which is a composite index of sleep disorders in the range of 0-20, with higher numbers indicating more severe insomnia. To ensure the accuracy of the measurements, the researchers used a body-weight model calibration scanner daily to record the subjects' bone mineral density (BMD) of the whole body, total hip, femoral neck, and spine to assess sleep duration and low bone mass (T score).
After adjusting for age, DXA machines, ethnicity, menopausal symptoms, education, smoking, physical activity, body mass index, alcohol use, bodily function, and sleep drug use, the researchers found:
Compared with the control group of 7 hours of sleep per night in the reference group, the BMD values of women who slept less than or equal to 5 hours per night were reduced by about 0.015, 0.012, 0.018 and 0.018 g/cm2, respectively, and the spinal and systemic BMD values of women who slept 6 hours per night were on average lower, and the difference was about 0.01 g/cm2 compared with women who slept for 7 hours;
In multiple logical models, women who slept 5 hours or less per night were significantly more likely to have low total hip and systemic bone mass compared to women who slept 7 hours a night. Similarly, women who slept less than 5 hours a night had a higher chance of developing osteoporosis in the hips, spine, and whole body;
For femoral neck bone density, the researchers failed to observe a statistically significant association with low bone mass or osteoporosis and sleep duration.
If future prospective studies can further demonstrate a causal relationship between sleep duration and bone density, sleep interventions may be an effective way to alleviate osteoporosis in postmenopausal women.
In our lifetime, we spend a third of our lives sleeping. The quality of sleep directly affects the remaining two-thirds of life. As a necessary process of life, sleep is an important part of the body's recovery, integration and consolidation of memory, and is an indispensable part of health. The fast pace of modern life makes "sleeping full" a luxury, and we should pay more attention to sleep health and create good sleep conditions for ourselves.
Source: Oxford University official website, only for academic exchanges.
Written by | Luna
Typography | Qiao Weijun
End
Resources:
[1] China Sleep Research Report (2022)
https://www.sgpjbg.com/baogao/64642.html
[2] Covassin N, Singh P, McCrady-Spitzer SK, et al. Effects of Experimental Sleep Restriction on Energy Intake, Energy Expenditure, and Visceral Obesity. J Am Coll Cardiol. 2022 Apr 5;79(13):1254-1265. doi: 10.1016/j.jacc.2022.01.038. PMID: 35361348.
[3] Brooks SJ, Katz ES, Stamoulis C. Shorter Duration and Lower Quality Sleep Have Widespread Detrimental Effects on Developing Functional Brain Networks in Early Adolescence. Cereb Cortex Commun. 2021;3(1):tgab062. Published 2021 Oct 26. doi:10.1093/texcom/tgab062
[4] Z Krizan, A Miller, G Hisler. Sleep, Volume 43, Issue Supplement_1, April 2020, Page A105, https://doi.org/10.1093/sleep/zsaa056.274
[5] M ller-Levet CS, Archer SN, Bucca G, et al. Effects of insufficient sleep on circadian rhythmicity and expression amplitude of the human blood transcriptome. Proc Natl Acad Sci U S A. 2013 Mar 19;110(12):E1132-41. doi: 10.1073/pnas.1217154110. Epub 2013 Feb 25. PMID: 23440187; PMCID: PMC3607048.
[6] Ochs-Balcom HM, Hovey KM, Andrews C, et al. Short Sleep Is Associated With Low Bone Mineral Density and Osteoporosis in the Women's Health Initiative. J Bone Miner Res. 2020 Feb;35(2):261-268. doi: 10.1002/jbmr.3879. Epub 2019 Nov 6. PMID: 31692127; PMCID: PMC8223077.
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