Sleep as a shield: A new study reveals that sleeping well before COVID-19 infection reduces the risk of post–COVID-19 condition (long COVID).
Post–COVID-19 condition (PCC) or “long COVID,” is the continuance of COVID-19 symptoms more than 4 weeks after acute infection. Anywhere from 20-70% of COVID-19 patients may develop long COVID, experiencing symptoms that may range from inconvenient to debilitating.
It is not well understood why some COVID-19 survivors have long COVID and some do not, but one team of investigators sought to determine whether a history of healthy sleep can protect against PCC. Sleep problems affect 1 in 3 people, and sleep disturbances are known to be a health risk factor.
Contagion has previously covered the potential linkage between sleep disturbances and long COVID breathlessness, with findings that sleep disturbance after COVID-19 hospitalization is associated with the PCCs dyspnea, anxiety, and muscle weakness. However, a new study examined the protective effect of sleep before COVID-19 infection.
The prospective cohort study, published in JAMA Network Open, sought to investigate whether multidimensional sleep health before and during the COVID-19 pandemic, before contracting COVID-19, was correlated with the risk of long COVID.
The investigators utilized data from the Nurses' Health Study II, conducted from 2015—2021. Participants who tested positive for COVID-19 infection (n = 2303) and completed COVID-19-related surveys (n = 32,249) between April 2020—November 2021 were included.
Sleep health was assessed before the pandemic (June 1, 2015—May 31, 2017) and during the early phase of the COVID-19 pandemic (April 1—August 31, 2020). The pre-pandemic sleep score was determined based on 5 dimensions, including morning chronotype, adequate sleep duration (7 to 8 hours per day), low insomnia symptoms, absence of snoring, and no frequent daytime dysfunction. The first COVID-19 substudy survey collected information on average daily sleep duration and sleep quality over the past 7 days.
COVID-19 infection and PCC (symptoms lasting ≥4 weeks) were self-reported during 1 year of follow-up. The investigators used Poisson regression models for comparisons between June 8, 2022—January 9, 2023.
After exclusions, a total of 1979 female nurses were included in the final analyses. The women were 97.2% White and averaged 64.7 years of age; 42.7% of them were frontline health care workers. Of these 1979 participants reporting a prior COVID-19 infection, 44.0% (n = 870) developed PCC.
Women with the highest pre-pandemic sleep score of 5 (indicating the healthiest sleep) had a 30% lower risk of developing PCC compared to those with a score of 0 or 1 (least healthy) (multivariable-adjusted relative risk, 0.70; 95% CI, 0.52-0.94; P for trend < .001). This association was consistent across frontline health care workers and nonhealth care workers.
Additionally, the absence of daytime dysfunction before the pandemic and good sleep quality during the pandemic were independently associated with a lower risk of PCC. These findings were similar when long COVID was defined as having 8 or more weeks of symptoms, or as having ongoing symptoms, at the time of PCC assessment.
The study suggests that maintaining healthy sleep patterns before and during the COVID-19 pandemic may offer protection against the development of long COVID. The study authors emphasized the importance of conducting further research to explore whether interventions targeting sleep health can help prevent or alleviate PCC symptoms.