Losing Just One Night's Sleep Changes Your Immune System, Study Finds

We all know sleep is important, but it takes up so much time. With responsibilities and diversions still looming from our waking life, the urge to skimp on sleep can be powerful.

Yet as a new study suggests, even a single night of sleep deprivation may cause significant upheaval in the immune system, potentially contributing to the development of conditions like obesity, diabetes, and heart disease.

The perils of chronic sleep deprivation are widely known, from mood changes and cognitive impairments to health problems like heart attacks or strokes.

There is abundant evidence linking poor sleep with these and other ailments, and abundant evidence suggesting health problems like these are commonly driven by chronic inflammation, the authors of the new study point out.

There is less evidence, however, about the specific mechanisms involved: How exactly could sleep deprivation lead to the systemic inflammation that goes on to impair people's health?

For the new study, researchers from the Dasman Diabetes Institute in Kuwait sought to understand the influence of sleep deprivation on circulating immune cells, such as monocytes, and its association with systemic inflammation.

Monocytes are large leukocytes, or white blood cells, that play key roles in the innate immune system, which provides the body's first line of defense against intruders. There are three subsets of monocytes in humans: classical, non-classical, and intermediate.

Non-classical monocytes patrol for pathogens in vasculature and extravascular tissues, the study's authors explain, using inflammatory cues to help them regulate the body's immune response.

The researchers recruited 276 healthy Kuwaiti adults with varying body mass indices (BMIs), 237 of whom ended up completing the study. They analyzed the subjects' sleep patterns, and monitored their blood for levels of different monocyte subsets as well as inflammation markers.

Obese participants had significantly lower sleep quality than leaner participants, the study found, along with higher chronic low-grade inflammation. They also had more non-classical monocytes, which correlated with lower sleep quality and increased pro-inflammatory markers.

In another part of the study, five healthy, lean adults submitted blood samples throughout a 24-hour period of sleep deprivation. These were compared to control blood samples taken after the participants had had a few days of refreshing sleep.

Even just 24 hours of sleep deprivation apparently altered the monocyte profiles in lean participants to resemble those of obese participants, a condition the researchers note is known to promote chronic inflammation.

The answer may seem obvious – just get more sleep – but it's rarely that simple in real life. Modern civilization conspires to keep us up late, argues lead author Fatema Al-Rashed, a researcher at the Dasman Diabetes Institute.

"Our findings underscore a growing public health challenge. Advancements in technology, prolonged screen time, and shifting societal norms are increasingly disruptive to regular sleeping hours," Al-Rashed says.

"This disruption in sleep has profound implications for immune health and overall well-being."

Future research should continue this examination of the links between sleep deprivation and immune changes, Al-Rashed and her colleagues write.

They also hope to learn if any interventions might help mitigate this effect, such as structured sleep therapies or guidelines for limiting use of technology.

"In the long term, we aim for this research to drive policies and strategies that recognize the critical role of sleep in public health," Al-Rashed says.

"We envision workplace reforms and educational campaigns promoting better sleep practices, particularly for populations at risk of sleep disruption due to technological and occupational demands.

"Ultimately, this could help mitigate the burden of inflammatory diseases like obesity, diabetes, and cardiovascular diseases," she says.

The study was published in The Journal of Immunology.