Sleep Loss and Inflammation

Not getting enough quality snooze time can spark disease-causing inflammation. Here's what you should know about sleep loss and inflammation.

If a cut on your hand swells, turns red, and hurts, it doesn’t take a medical genius to know the wound is inflamed. This type of inflammation is a natural, healthy response from your immune system as it gears up to fight bacteria or some other invader that could be harmful. In time, most inflammation from a wound like a splinter or cut goes away as healing takes place. 

However, in autoimmune diseases, like psoriasis and rheumatoid arthritis, the immune system mistakes the body’s own healthy cells against invaders and attacks them, resulting in inflammation that can be long-lasting and painful. And in recent years, scientists have found another type of inflammation can take place inside the body without causing any obvious symptoms — at least, not at first. But over time, this chronic inflammation plays a role in the development of a host of serious diseases, from cancer and depression to heart disease. 

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Researchers have discovered some causes of this silent, internal inflammation. For example, Harvard investigators found obesity sparks inflammation and may explain why being overweight raises the risk of type 2 diabetes and other ills. And now a University of California at Los Angeles (UCLA) analysis of 72 studies concludes another common problem, poor quality sleep, is also linked to inflammation inside the body

UCLA Semel Institute for Neuroscience researchers looked at the amount and quality of sleep reported by over 50,000 research subjects in the analyzed studies. They also noted the levels of three inflammatory markers found in the research participants’ blood — C-reactive protein (produced by the liver in response to inflammation), interleukin-6 (secreted by immune system cells wherever there is acute or chronic inflammation), and tumor necrosis factor-alpha (an immune system protein released in reaction to systemic inflammation). 

The results showed two of these indicators of inflammation spiked upwards, depending on whether people got too much or too little sleep or if their shut-eye was disturbed. Specifically, increased levels of C-reactive protein and interleukin-6 were noted in people who complained of insomnia or poor sleep quality and those who tended to sleep an extra-long time at night (more than eight hours). Sleeping less than eight hours a night was associated with increased levels of C-reactive protein, too.

The findings suggest common sleep disturbances, including insomnia, are a factor causing inflammation, the UCLA research team noted. Previous studies have shown increased levels of C-reactive protein and interleukin-6, the two inflammatory markers linked to less-than-ideal sleep, are known to raise the risk of cardiovascular events, high blood pressure, and type 2 diabetes.

So treatments to improve sleep and encourage sleeping an optimum number of hours — not too little or too much — could be a strategy for reversing inflammation inside the body and reducing the risk of inflammatory illnesses, according to Michael R. Irwin, MD, professor of psychiatry and biobehavioral sciences at UCLA’s David Geffen School of Medicine, who headed the study.

In fact, Irwin believes it’s time for sleep disturbances and insomnia to be considered behavioral risk factors for inflammation in the same way unhealthy diets and sedentary lifestyles are now considered risks for health woes.

The Centers for Disease Control and Prevention (CDC) points out insufficient sleep can play a role in the development and management of a number of chronic diseases and conditions, including diabetes, cardiovascular disease, obesity, and depression. Getting enough good quality sleep can improve symptoms of many of these health problems — and it may help prevent them from developing in the first place. 

The CDC offers more information on sleep’s link to health, including tips on how to improve you own night’s sleep. 

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