Dubai, United Arab Emirates (CNN) — A new study published in the Journal of Experimental Medicine on September 21 found that chronic sleep deprivation in a small group of healthy adults increased the production of immune cells associated with inflammation, in parallel with altering DNA. for immune cells.
“Not only is the number of immune cells elevated, but they may be delivered and programmed differently by the end of the six weeks of treatment,” said study co-author Cameron McAlpin, associate professor of cardiology and neuroscience at the Icahn School of Medicine at Mount Sinai University in New York City. sleep deprivation.”
“These two factors together can predispose a person to developing diseases such as cardiovascular disease,” he continued.
Experts said that a certain amount of immune system inflammation is necessary for the body to be able to fight infections and heal infections, but an overactive immune system can be harmful and increase the risk of autoimmune disorders and chronic diseases.
“This work is consistent with the views in the field that sleep restriction may increase the risk of type 2 diabetes and high blood pressure,” said Stephen Malin, assistant professor in the Department of Kinesiology and Health at Rutgers University in New Jersey, US, who was not involved in the study.
“In practical terms, these findings support ideas for developing good sleep habits so that you most of the time get enough sleep,” Malin added.
Good sleep heals
In order for the body to be healthy, it must go through four stages of sleep several times a night. During the first two phases, the body begins to lower its rhythm, preparing us for the third phase, deep slow-wave sleep, in which the body literally restores strength at the cellular level, with the goal of repairing the damage caused by the stress of the day and anchoring the memories in long-term storage.
Rapid eye movement (REM) sleep is the last stage in which we dream. Studies have shown that loss of REM sleep may cause memory deficits and poor cognitive outcomes, in addition to heart disease, other chronic diseases, and early death.
On the other hand, years of research have found that sleep, especially deeper and more therapeutic sleep, boosts immune function.
Since each sleep stage takes about 90 minutes, most adults need between 7 and 8 hours of relatively uninterrupted sleep to achieve restorative sleep, according to the US Centers for Disease Control and Control.
Increase in signs of inflammation
The small study included 14 healthy young men who did not have trouble sleeping. McAlpine said the study was also long, which gave it strengths.
He continued, “Many studies have been conducted about sleep that lasted one day, or two days, or perhaps a week or two,” noting that “a few of them followed the effect of sleep over a period of six long weeks, and this is what we did.”
Study participants wore an accelerometer around their wrist, which allowed the researchers to track the quality and duration of their sleep over 24 hours. Over the first six weeks, each study participant slept between 7 and 8 hours, the recommended amount of sleep for adults by the US Centers for Disease Control and Control. Over the next six weeks, these people slept less by 90 minutes each night.
At the end of each six-week cycle, blood was drawn in the morning and evening, and the reaction of immune cells was analyzed. No negative changes were found in people who got enough sleep. However, after study participants spent six weeks of sleep restriction, blood tests found an increase in a specific type of immune cell when blood was drawn during the evening.
“The cause of this sleep restriction disorder is very specific, and it affects one type of immune cell known as a monocyte, while other immune cells do not respond,” McAlpin explained, noting that “this is an indication of inflammation.”
Blood tests also showed genetic changes within the single-celled immune cells after a prolonged period of sleep deprivation. Epigenomes are proteins and chemicals that sit like freckles on each gene, waiting to tell the gene “what to do, where, and when to do it,” according to the National Human Genome Research Institute.
The epigenome literally turns genes on and off, often dependent on environmental triggers and human behaviors, such as smoking, eating an inflammatory diet, or suffering from chronic poor sleep.
“The results show that factors that may modulate the gene expression of proteins associated with inflammation, known as epi-genomes, are modified by sleep restriction,” Malin said.
“This modification increases the risk that immune cells will become more inflammatory in nature. The study did not perform functional or clinical measures to confirm disease risk, but it lays the foundation for future studies to look at these mechanisms.”
Are the changes permanent?
The immune activity of the sleep-deprived mice mirrored that of the human, as the production of immune cells increased, and genetic changes were seen in the DNA of the immune cells. In these studies, mice were allowed to get good sleep for 10 weeks before they were tested again.
Despite getting enough sleep for an extended period of time, the researchers found that the DNA changes remained, and the immune system continued to overproduce it, making the mice more susceptible to infections and disease.
“Our findings suggest that sleep recovery is not able to completely reverse the effects of poor sleep in mice,” McAlpin explained, adding that his lab continues to work with people to see if this finding holds for humans as well.
“This study begins by identifying the biological mechanisms that link sleep and long-term immune health,” Philip Swirsky, lead author of the study and director of the Icahn Heart and Vascular Research Institute at Mount Sinai, said in a statement. Inflammation, while interrupted sleep increases the risk of infection.”