Summary: Sleep disturbances and long sleep duration are both associated with an increased risk for inflammation, a new study reports.
A new meta-analysis in Biological Psychiatry reports that sleep disturbances and long sleep duration are associated with increases in markers of inflammation.
“It is important to highlight that both too much and too little sleep appears to be associated with inflammation, a process that contributes to depression as well as many medical illnesses,” said Dr. John Krystal, Editor of Biological Psychiatry.
Insufficient sleep is considered a public health epidemic by the Centers for Disease Control and Prevention. Common sleep disturbances, such as insomnia, have been associated with increased risk of inflammatory disease and mortality.
Substances that increase in response to inflammation and circulate in the blood stream, such as C-reactive protein (CRP) and interleukin-6 (IL-6), predict adverse health conditions including cardiovascular events, hypertension, and type 2 diabetes. Many studies have investigated the mechanism behind the association between sleep health and immunity, but variations between studies have made it difficult to understand the effects.
In a recent article, Michael Irwin, Richard Olmstead and Judith Carroll, all of the Cousins Center for Psychoneuroimmunology, UCLA Semel Institute for Neuroscience, University of California, Los Angeles, systematically reviewed existing studies for associations between sleep and inflammatory markers. The meta-analysis examined 72 different articles, which included over 50,000 participants from population-based and clinical studies. The researchers looked at CRP, IL-6, and tumor necrosis factor α (TNFα) as indicators of inflammation.
People with a normal sleep duration get 7-8 hours of shut-eye per night. The analysis showed that sleep disturbance (poor sleep quality or complaints of insomnia) and long sleep duration (more than 8 hours) were associated with increased levels of CRP and IL-6. Shorter sleep duration was associated with increased levels of CRP. No associations were found with TNFα.
According to Irwin, sleep disturbance or insomnia should be regarded as behavioral risk factors for inflammation, similar to the adverse effects of high fat diet or sedentary behavior. Treatments targeting sleep behavior could be a strategy for reversing the inflammation and reducing risk of inflammatory illnesses.
“Together with diet and physical activity, sleep health represents a third component in the promotion of health-span,” said Irwin.
The authors’ affiliations, and disclosures of financial and conflicts of interests are available in the article. John H. Krystal, M.D., is Chairman of the Department of Psychiatry at the Yale University School of Medicine, Chief of Psychiatry at Yale-New Haven Hospital, and a research psychiatrist at the VA Connecticut Healthcare System.
Source: Rhiannon Bugno – Elsevier
Image Source: This NeuroscienceNews.com image is credited to Elsevier.
Original Research: Abstract for “Sleep Disturbance, Sleep Duration, and Inflammation: A Systematic Review and Meta-Analysis of Cohort Studies and Experimental Sleep Deprivation” by Michael R. Irwin, Richard Olmstead, Judith E. Carroll in Biological Psychiatry. Published online June 1 2016 doi:10.1016/j.biopsych.2015.05.014
Sleep Disturbance, Sleep Duration, and Inflammation: A Systematic Review and Meta-Analysis of Cohort Studies and Experimental Sleep Deprivation
Sleep disturbance is associated with inflammatory disease risk and all-cause mortality. Here, we assess global evidence linking sleep disturbance, sleep duration, and inflammation in adult humans.
A systematic search of English language publications was performed, with inclusion of primary research articles that characterized sleep disturbance and/or sleep duration or performed experimental sleep deprivation and assessed inflammation by levels of circulating markers. Effect sizes (ES) and 95% confidence intervals (CI) were extracted and pooled using a random effect model.
A total of 72 studies (n > 50,000) were analyzed with assessment of C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor α (TNFα). Sleep disturbance was associated with higher levels of CRP (ES .12; 95% CI = .05–.19) and IL-6 (ES .20; 95% CI = .08–.31). Shorter sleep duration, but not the extreme of short sleep, was associated with higher levels of CRP (ES .09; 95% CI = .01–.17) but not IL-6 (ES .03; 95% CI: −.09 to .14). The extreme of long sleep duration was associated with higher levels of CRP (ES .17; 95% CI = .01–.34) and IL-6 (ES .11; 95% CI = .02–20). Neither sleep disturbances nor sleep duration was associated with TNFα. Neither experimental sleep deprivation nor sleep restriction was associated with CRP, IL-6, or TNFα. Some heterogeneity among studies was found, but there was no evidence of publication bias.
Sleep disturbance and long sleep duration, but not short sleep duration, are associated with increases in markers of systemic inflammation.
“Sleep Disturbance, Sleep Duration, and Inflammation: A Systematic Review and Meta-Analysis of Cohort Studies and Experimental Sleep Deprivation” by Michael R. Irwin, Richard Olmstead, Judith E. Carroll in Biological Psychiatry. Published online June 1 2016 doi:10.1016/j.biopsych.2015.05.014