March 24, 2021 – Health care workers who sleep well and are satisfied with their jobs are less likely to develop COVID-19 despite their regular exposure to patients infected with the coronavirus, a new study shows.
For each additional hour of sleep at night, for example, risk for COVID-19 dropped by 12% in a study of 2,844 frontline healthcare workers.
Also, those who reported work-related burnout everyday were 2.6 times more likely to have been infected withCOVID-19, to have COVID-19 for a longer time, and to experience more severious symptoms.
"This study underscores the importance of nonhygiene related risk factors for COVID-19 and supports a holistic approach to health ― including optimal sleep and job stress reduction to protect our health care workers from this and future pandemics," senior author Sara Seidelmann, MD, told Medscape.
Seidelmann and colleagues note, "Our findings add to the literature that sleep duration at night, sleep problems and burnout may be risk factors for viral illnesses like COVID-19."
This is the first study to link COVID-19 risk to sleep habits ― including number of hours of sleep at night, daytime napping hours, and severe sleep problems ― among health care workers across multiple countries.
The study was published online March 22 in BMJ Nutrition, Prevention and Health.
The researchers surveyed health care professionals in specialties considered high risk for exposure to SARS-CoV-2: critical care, emergency care, and internal medicine.
Interestingly, the association between sleep and burnout risk factors and COVID-19 did not vary significantly by specialty. "We didn't detect any significant interactions between age, sex, specialty, or country," said Seidelmann, assistant professor of clinical medicine at Columbia University College of Physicians and Surgeons in New York City, and an internist at Stamford Hospital, Stamford, CT.
In addition to the 12% lower risk associated with each additional hour of sleep at night, each 1 additional hour of daytime napping was linked with a 6% increased risk for COVID-19.
Daytime napping slightly increased risk for COVID-19 in 5 of the 6 countries included in the study: France, Germany, Italy, the United Kingdom, and the United States. In contrast, in Spain, napping did not have a significant effect.
The survey asked health care workers to recall nighttime sleep duration, sleep disorders, and burnout in the year prior to onset of the COVID-19 pandemic.
‘Significant, Close Contact’ With COVID-19?
The study was conducted from July 17 to Sept. 25, 2020. Lead author Hyunju Kim, NP, Seidelmann, and colleagues identified health care workers from the Survey Healthcare Globus (SHG) network.
Of the respondents, 72% were men. The average age was 48 years, and the study population was 77% white, 12% Asian, 6% mixed, 2% Black, and 1% other.
Of the study participants 568 health care workers self-reported having COVID-19.
All 2,844 participants answered yes to a question about having "significant close contact" with COVID-19 patients in their workplace.
More Burnout, Greater Risk
The health care workers reported the severity of any work-related burnout. Those who reported having burnout rarely or weekly had a 1.3 to 1.4 greater chance of reporting COVID-19 compared to those who reported no burnout, for example.
Reporting a high level of burnout was also linked to about three times the risk for having COVID-19 of longer duration and of greater severity.
What drives the association between sleep problems, burnout, and higher risk for COVID-19 and severe COVID-19 remains unknown.
"The mechanism underlying these associations isn't clear, but suboptimal sleep, sleep disorders, and stress may result in immune system dysregulation, increased inflammation, and alterations in hormones such as cortisol and melatonin that may increase vulnerability to viral infections," Seidelmann said.