Sleeping too much or too little may increase risk for infection

Individuals who slept fewer than 6 hours or more than 9 hours each night had an increased risk for infection compared with those who slept 7 to 8 hours, according to a study published in Frontiers in Psychiatry.

While prior literature has identified links between sleep and vulnerability to infection, “most previous observational studies have looked at the association between sleep and infection in a sample of the general population,” Ingeborg Forthun, PhD, a guest researcher in the department of global public health and primary care at the University of Bergen, said in a press release.

“We wanted to assess this association among patients in primary care, where we know that the prevalence of sleep problems is much higher than in the population at large,” Forthun said.

In the Norway-based study, the researchers distributed questionnaires assessing sleep length, quality and other related factors to patients within waiting rooms of general practitioners.

The questionnaires also asked patients about infections in the previous 3 months, and whether antibiotics had been used and to what extent.

A total of 1,848 participants completed the surveys. Among them, the mean age was 52 years and 60.6% were women.

Overall, 21% of respondents reported sleeping fewer than 6 hours and 2% reported sleeping more than 9 hours. Overall, 46.9% of respondents fulfilled the criteria for chronic sleep problems.

Compared with patients who slept 7 to 8 hours, patients who slept fewer than 6 hours had a 25% (95% CI, 1.11-1.46) increased risk for infection and a 57% increased risk for antibiotic use (95% CI, 1.13-2.18), according to the researchers.

Similarly, patients who slept more than 9 hours had a 44% (95% CI, 1.12-1.84) increased risk for infection compared with patients who slept for 7 to 8 hours.

Forthun and colleagues also observed an increased risk for infection (adjusted RR [aRR] = 1.15; 95% CI, 1.05-1.27) and antibiotic use (aRR = 1.47; 95%, CI 1.16-1.87) in those who had a chronic insomnia disorder, as well as an increased infection risk (aRR = 1.13; 95% CI, 1.03-1.24) and antibiotic use risk (aRR = 1.33; 95% CI, 1.05-1.69) among those with a chronic sleep problem.

The researchers noted several limitations of the study. It was conducted in the first year of the COVID-19 pandemic, potentially lowering the risk for infection due to virus control and increasing the number of online consultations, which may have impacted the study’s representatives.

Forthun and colleagues pointed out that while insomnia is common among patients, it is often under-recognized by general practitioners.

“Cognitive behavioral therapy for insomnia has been found to be highly effective in a primary care setting, and there is also suggestive evidence that such treatment can reduce the level of [c-reactive protein] in the blood,” they wrote.

Ultimately, “increased awareness of the importance of sleep, not only for general well-being, but for patients’ health, is needed both among patients and general practitioners,” Forthun said in the release.

References:

• Forthun I, et al. Front Psychiatry. 2023;doi:10.3389/fpsyt.2023.1033034.
• Sleep too much or too little and you might get sick more, scientists find. https://www.eurekalert.org/news-releases/980971. Published March 2, 2023. Accessed March 6, 2023.