A National Institute of Health supported study performed in humans and mice revealed that getting a good night’s sleep supports production and programming of hematopoietic stem cells, which are integral for the normal functioning of the body’s immune system.
This study indicated that getting enough sleep influenced the environment where a type of white blood cell called a monocyte could grow, develop, and get its marching orders in support of immune function. This process is called hematopoiesis and it happens in the bone marrow.
“What we are learning is that sleep modulates the production of cells that are the protagonists – the main actors – of inflammation. Good, quality sleep reduces that inflammatory burden,” said Filip K. Swirski, Ph.D, and a senior study author and director of the Cardiovascular Research Institute at Icahn School of Medicine at Mount Sinai in New York City.
Researchers studied how sleep disruptions in humans and mice increased levels of these immune cells, and therefore altered the environment in the bone marrow.
In another study led by Marie-Pierre St-Onge, Ph.D., at Columbia University in New York City, 14 adults enrolled in a clinical research trial that studied their sleep patterns for six weeks. They were split into two groups with one group getting 7.5 hours of sleep, or what the prevailing scientific attitudes consider to be enough sleep, while the alternative group endured conditions that created sleep deficiency.
Sleep deficiency is more than just not enough sleep
Sleep deficiency includes one of the following symptoms:
- You don’t get enough sleep in general (sleep deprivation)
- Experience an altered sleep schedule where 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
The general consensus is that most adults should get between seven and eight hours of uninterrupted sleep each night, while older adults need between seven and nine and children between the ages of 11-17 need between eight to ten hours of sleep.
The conditions were created by reducing the sleep deficiency’s cohort available sleep time by 1.5 hours, letting them get six hours of sleep each night. Sleep conditions were separated by a six-week period wherein participants could return to their normal sleep habits.
Blood was then taken in the morning and again in the afternoon during the fifth and sixth weeks for each sleep condition and researchers discovered that the adults that didn’t get enough sleep had higher levels of circulating monocytes in the afternoon. They also had elevated 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. The change isn’t permanent, but they continue to self-replicate at a higher rate for weeks,” said Swirski.
Greater production of immune cells creates an immune environment conducive to the acceleration of clonal hematopoiesis, which is an age-related condition linked to enhanced risk for cardiovascular disease. Prior studies noted that some genetic mutations push the creation of these stem cells as well, but this study discovered that putting pressure on the hematopoietic system through sleep restriction can produce similar results.
“Sleep impacts optimal functioning of nearly every cell and organ in the body. 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,” said Marishka K. Brown, Ph.D, director of the National Center on Sleep Disorders Research.
The study authors indicated that their discoveries cemented how important it was to develop strong sleep habits early in life, which could theoretically reduce the severity of other inflammation related conditions like sepsis.