Adults who cut back on sleep for six weeks had increased markers of inflammation
Getting a consistent good night’s sleep supports normal production and programming of hematopoietic stem cells, a building block of the body’s innate immune system, according to a small National Institutes of Health-supported study in humans and mice. Sleep has long been linked to immune function, but researchers discovered that getting enough of it influenced the environment where monocytes – a type of white blood cell – form, develop, and get primed to support immune function. This process, hematopoiesis, occurs in the bone marrow.
The study published in the Journal of Experimental Medicine.
“What we are learning is that sleep modulates the production of cells that are the protagonists – the main actors – of inflammation,” said Filip K. Swirski, Ph.D., a senior study author and director of the Cardiovascular Research Institute at Icahn School of Medicine at Mount Sinai, New York City. “Good, quality sleep reduces that inflammatory burden.”
To assess these mechanisms, researchers studied associations between sleep and monocyte production in humans and mice, which expanded on findings from prior mathematical models. They analyzed how sleep disruptions increased circulating levels of these immune cells and changed the environment in the bone marrow.
In a collaborative study led by Marie-Pierre St-Onge, Ph.D., at Columbia University, New York City, 14 adults enrolled in the clinical research trial. They each participated in a six-week study arm that emulated getting enough sleep (about 7.5 hours each night) or that created sleep deficiency. To model sleep restriction, adults reduced their nighttime sleep by 1.5 hours – getting about 6 hours of sleep each night. Sleep conditions were separated by a six-week “washout” period, during which participants returned to their normal sleep patterns.
Morning and afternoon blood samples were collected during the fifth and sixth weeks for each sleep condition. Researchers found that when adults didn’t get enough sleep, they had higher levels of circulating monocytes in the afternoon. They also had higher numbers of immune stem cells in the blood and evidence of immune activation.
“The stem cells have been imprinted, or genetically altered, under the influence of sleep restriction,” Swirski said. “The change isn’t permanent, but they continue to self-replicate at a higher rate for weeks.”
A higher production of immune cells creates a more homogenous immune environment, which can accelerate clonal hematopoiesis, an age-related condition that has been linked to increased risks for cardiovascular disease.
Prior studies have identified genetic mutations that drive the proliferation of hematopoietic stem cells. However, this study found that putting pressure on the hematopoietic system, in this case through sleep restriction, produced similar results without the driver mutations.
“Sleep impacts optimal functioning of nearly every cell and organ in the body,” said Marishka K. Brown, Ph.D., director of the National Center on Sleep Disorders Research, located within the National Heart, Lung, and Blood Institute (NHLBI). “The mechanistic insight from this study supports findings from larger population studies, which have shown that sleep can have a protective effect against a variety of conditions, including heart disease, cancer, and dementia.”
The study authors said their findings also underscored the importance of establishing sound sleep patterns early in life, which may reduce the severity of other inflammatory conditions such as sepsis. Most adults should get 7-8 hours of uninterrupted sleep each night. Older adults need about 7-9 hours, while children ages 11-17 need about 8-10 hours.
The study was partially funded by NHLBI and the National Center for Advancing Translational Sciences.
To learn more about sleep health, visit https://www.nhlbi.nih.gov/health-topics/education-and-awareness/sleep-health.
To learn more about the NIH Sleep Research Plan, visit www.nhlbi.nih.gov/sleep-research-plan/about.
Study: McAlpine CS, Kiss MG, Zuraikat FM, et al. Sleep exerts lasting effects on hematopoietic stem cell function and diversity. J Exp Med. 2022; doi: 10.1084/jem.20220081
What Are Sleep Deprivation and Deficiency?
Sleep deprivation is a condition that occurs if you don’t get enough sleep. Sleep deficiency is a broader concept. It occurs if you have one or more of the following:
- You don’t get enough sleep (sleep deprivation)
- You sleep at the wrong time of day
- You don’t sleep well or get all the different types of sleep your body needs
- You have a sleep disorder that prevents you from getting enough sleep or causes poor-quality sleep
This topic focuses on sleep deficiency.
Sleeping is a basic human need, like eating, drinking, and breathing. Like these other needs, sleeping is vital for good health and well-being throughout your lifetime.
According to the Centers for Disease Control and Prevention, about 1 in 3 adults in the United States reported not getting enough rest or sleep every day.
Nearly 40% of adults report falling asleep during the day without meaning to at least once a month. Also, an estimated 50 to 70 million Americans have chronic, or ongoing, sleep disorders.
Sleep deficiency can lead to physical and mental health problems, injuries, loss of productivity, and even a greater likelihood of death. To understand sleep deficiency, it helps to understand what makes you sleep and how it affects your health.
Learn the science behind how sleep works.
Sleep deficiency can interfere with work, school, driving, and social functioning. You might have trouble learning, focusing, and reacting. Also, you might find it hard to judge other people’s emotions and reactions. Sleep deficiency also can make you feel frustrated, cranky, or worried in social situations.
The symptoms of sleep deficiency may differ between children and adults. Children who are sleep deficient might be overly active and have problems paying attention. They also might misbehave, and their school performance can suffer.
Sleep deficiency is linked to many chronic health problems, including heart disease, kidney disease, high blood pressure, diabetes, stroke, obesity, and depression.
Sleep deficiency is also linked to a higher chance of injury in adults, teens, and children. For example, sleepiness while driving (not related to alcohol) is responsible for serious car crash injuries and death. In older adults, sleep deficiency may be linked to a higher chance of falls and broken bones.
Sleep deficiency has also played a role in human mistakes linked to tragic accidents, such as nuclear reactor meltdowns, grounding of large ships, and plane crashes.
A common myth is that people can learn to get by on little sleep with no negative effects. However, research shows that getting enough quality sleep at the right times is vital for mental health, physical health, quality of life, and safety.