Sleep quality and inflammatory markers are linked in patients with schizophrenia, according to research published in The American Journal of Geriatric Psychiatry. Patients with schizophrenia, and women in particular, have a high-risk for sleep disturbances and inflammation.
Researchers sought to identify demographic, clinical, and cognitive factors that may affect this link. To examine the relationship between sleep disturbances and inflammation in individuals with schizophrenia, researchers tested the associations of this relationship with age, sex, and other variables in a cross-sectional case-control study. The study enrolled 144 outpatients with schizophrenia and 134 controls between the ages of 26 and 64 years. Researchers assessed sleep quality and duration, mental and physical health, and inflammatory biomarkers. In addition, patients underwent cognitive assessments including executive functioning and subjective cognitive complaints.
Participants with schizophrenia had longer sleep duration and worse sleep quality. Patients in the schizophrenia group also had higher levels of high-sensitivity C-reactive protein, interleukin-6, and tumor necrosis factor-α than the control group. Researchers found that cognitive complaints and sleep quality were significantly associated with high-sensitivity C-reactive protein levels, and executive functioning and sleep quality were associated with interleukin-6 levels. Overall, researchers found that worse sleep quality was associated with increased levels of pro-inflammatory markers among the participants with schizophrenia.
In addition, women with schizophrenia have significantly worse sleep quality than men with schizophrenia. This suggests that sleep quality and inflammatory markers are linked among people with schizophrenia.
The study was limited by its cross-sectional design and use of subjective sleep measures.
Researchers advocate further examination of the sleep-inflammation link, clinical outcomes, and sex-specific factors. They note that, “Understanding the biological mechanisms of a potentially modifiable target like sleep may help guide future development and assessment of interventions to improve sleep and cognition.” This future research may help to develop personalized interventions and new therapies for sleep and inflammation.
Disclosure: Sonia Ancoli-Israel, PhD, is a consultant for Pfizer, Eisai, Purdue, and Merck.
Lee EE, Ancoli-Israel S, Eyler LT, et al. Sleep disturbances and inflammatory biomarkers in schizophrenia: focus on sex differences [published online October 11, 2018]. Am J Geriatr Psychiatry. doi: 10.1016/j.jagp.2018.09.017