Those who work in the health sector during the Covid-19 pandemic are particularly at risk of contracting the virus. A study now shows that lack of sleep and stress also play a role: Health workers who reported frequent sleep problems had an 88 percent increased risk of contracting Sars-CoV-2. Severe stress at work also correlated with a higher likelihood of contracting Covid-19 and a longer, more severe course. In contrast, every additional hour of night sleep reduced the risk by twelve percent.
The Covid 19 pandemic poses particular challenges for many people, including health workers: Many doctors and nurses have daily contact with infected patients, have to cope with an increased workload and at the same time pay special attention to hygiene and their own protection. Previous studies have already shown that health workers who are involved in the care of Covid-19 patients have a greatly increased risk of developing the disease themselves. The greatest risk factor is repeated exposure to the virus.
Interviewed health workers from six countries
A team led by Hyunju Kim from Johns Hopkins University in Baltimore has now shown that lack of sleep and workload are also associated with the risk of Covid 19 disease. From July to September 2020, the researchers surveyed 2,844 doctors and nurses from Germany, France, Italy, Spain, Great Britain and the USA about working conditions, sleeping habits and health status. All respondents were in regular contact with Covid 19 patients at this time. 568 of them reported having their own Covid 19 disease.
“The participants with their own Covid 19 disease reported fewer hours of sleep at night, a little more naps during the day and one or more sleep problems. They also said more often that they felt burned out from work at least once a month, ”summarize the researchers. In order to capture more than a snapshot, the questions about sleep duration and problems as well as the feeling of being burned out from work did not relate to everyday life during the pandemic, but to the previous year. On average, the respondents said they slept six to seven hours at night.
Night sleep for health
If the researchers calculated demographic data, the exposure load and other influencing factors, they found that every additional hour of night sleep was associated with a twelve percent lower risk of illness. On the other hand, those who stated that they regularly had problems falling asleep and staying asleep and often took sleeping pills had an 88 percent higher risk compared to people without sleep problems.
The effect of daytime naps was ambiguous: in France and the United States, health workers who slept regularly during the day had a slightly increased risk of developing Covid-19. In Spain, on the other hand, the trend was the opposite. “When it comes to daytime naps, there may be cultural differences,” the researchers say. “In some countries they can be a sign of stress and lack of sleep, while in other countries they are a tradition – like the siesta in Spain.”
Well-being is important for the immune system
Stress at work was also associated with a higher likelihood of illness and more severe, longer courses. Compared to those who reported no feelings associated with burnout, those who experienced this on a daily basis were more than twice as likely to be infected with Covid-19. These respondents also said that their infection was associated with more severe symptoms and that they needed a longer recovery period about three times as often. These results apply regardless of how intensively those affected had contact with Covid 19 patients. It should be noted, however, that the survey only raised the self-assessment of those affected and could therefore be distorted by their memories.
“Earlier studies have suggested that burnout can cause illness, directly or indirectly, as occupational stress affects the immune system and changes cortisol levels,” the authors write. A lack of sleep has also previously been shown to be a risk factor for infectious diseases such as the flu and the common cold. The exact mechanism is unclear, however. “One hypothesis is that lack of sleep and sleep disorders can negatively affect the immune system by increasing inflammation-enhancing cytokines and histamines,” explain Kim and colleagues. The new findings could therefore also be relevant for people in other life situations and professions. They confirm that chronic stress can impair the immune system – and that this is also evident with Covid-19.
Source: Hyunju Kim (John Hopkins University, Baltimore, USA) et al., BMJ Nutrition Prevention & Health, doi: 10.1136 / bmjnph-2021-000228