Poor Sleep After COVID Hospitalization: Dyspnea Is Part of the Equation

Poor sleep may be traced back to lingering shortness of breath and decreased lung function from prior COVID-19 illness in patients requiring hospitalization, the CircCOVID study found.

Approximately half a year following hospitalization for COVID-19, 62% of patients reported that they experienced poor sleep quality, while 53% felt their sleep had gotten worse since leaving the hospital. This was supported by actigraphy results showing that these individuals had longer duration of sleep but lower sleep regularity and lower sleep efficiency compared with matched U.K. Biobank participants, reported John Blaikley, MBBS, PhD, of the University of Manchester, England, and co-authors.

In turn, poor sleep quality, worsening sleep quality, and low sleep regularity following hospital discharge were associated with higher dyspnea scores and impaired lung function by forced vital capacity, according to the multicenter, prospective study published in The Lancet Respiratory Medicine. These findings were also presented at European Congress of Clinical Microbiology & Infectious Diseases in Copenhagen, Denmark.

"The associations described in this study between sleep disturbance and reduced muscle function, anxiety, and dyspnea suggest that sleep disturbance could be an important driver of the post-COVID-19 condition," the group wrote. "If this is the case, then interventions targeting poor sleep quality could be used to manage multimorbidity and convalescence following hospital admission for COVID-19, with the aim of potentially improving patient outcomes."

The authors did note that accounting for patient anxiety and muscle function could impact some of the observed impacts of dyspnea. An estimated 39% of the relationship between poor sleep quality and dyspnea was mediated by anxiety, and 36% by reduced muscle function. Similarly, anxiety mediated 36% of the relationship between sleep quality deterioration and dyspnea, whereas reduced muscle function mediated 27% of the relationship.

"Sleep disturbance following hospital admission is common regardless of the original reason for admission. Despite its prevalence, the clinical implications of sleep disturbance during recovery from an acute illness are not well understood. In experimental settings, sleep disturbance is causally associated with two recognised causes of dyspnea: anxiety and muscle weakness," Blaikley and colleagues wrote.

Based on the current report, it is still unclear whether sleep disturbance is causing anxiety or whether anxiety is contributing to poor sleep, according to W. Cameron McGuire, MD, of the University of California San Diego, and co-authors of an accompanying editorial.

Other questions to be answered, they said, include whether the documented abnormalities in pulmonary microvasculature in previous studies are contributing to dyspnea, and for clinicians, whether certain therapies may mitigate dyspnea during COVID-19 recovery.

Approximately 13.9% of COVID-19 patients currently report long COVID-19 symptoms, with 31% of those patients citing disrupted sleep among their symptoms. Sleep plays a vital role in overall health, with poor sleep habits associated with increased stroke risk, asthma, and worsening mental health.

CircCOVID was a substudy of the Post-hospitalisation COVID-19 study (PHOSP-COVID) that enrolled 2,468 adults hospitalized for COVID-19 in the U.K. who were discharged from March 2020 to October 2021.

There were 638 individuals included who completed both the Pittsburgh Sleep Quality Index questionnaire and numerical rating scale for sleep quality. Participant sleep quality worsened by, on average, three points on the index when followed-up at 2 to 7 months, and two points at 10 to 14 months post-discharge.

The 729 participants who provided device-based measures of sleep had been instructed to wear an accelerometer on their wrist for 14 days straight. These patients were then matched with similar U.K. Biobank participants, some without hospitalization and some with a recent hospitalization for pneumonia, for comparison.

Besides the minority of patients providing follow-up data, the CircCOVID study was also limited by the potential for recall and selection bias.

"In theory, the most severely affected patients would be least likely to present for follow-up. Conversely, patients who are sometimes labeled as having psychosomatic complaints might be those most likely to seek follow-up care," McGuire and colleagues noted.

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