Poor sleep quality, deterioration in sleep quality, and sleep regularity were all linked to impaired lung function.
Shortness of breath is among the most common symptoms reported by patients with post-acute sequalae of COVID-19, commonly called long COVID.
Breathlessness, or dyspnea, is reported by approximately half of COVID-19 patients admitted to the hospital. Additionally, many patients hospitalized with COVID-19 report subsequent sleep disturbance.
One study, published in The Lancet Respiratory Medicine and presented at the 2023 European Congress of Clinical Microbiology & Infectious Diseases (ECCMID), examined the prevalence and characteristics of sleep disturbance after hospital discharge for COVID-19 infection. The investigators sought to determine whether post-COVID-19 sleep disturbance was associated with dyspnea.
The prospective multicenter cohort study, CircCOVID, investigates the effects of circadian disruption and sleep disturbance on COVID-19 infection recovery. The study patients, aged 18 years and older, had been hospitalized with COVID-19 and were discharged between March 2020-October 2021.
The study investigators collected follow-up data at 2 timepoints: 2-7 months after hospital discharge and 10-14 months after discharge. They assessed sleep quality with the Pittsburgh Sleep Quality Index questionnaire, a numerical rating scale, and an accelerometer worn on the wrist for 14 days.
The participants were also clinically phenotyped at the early timepoint after discharge, including symptom assessment, muscle function, dyspnea, and lung function measurement. The investigators utilized multivariable linear regression to define associations of sleep disturbance with the primary study outcome, breathlessness, as well as other clinical symptoms.
Sleep quality data were analyzed for 638 participants at the early timepoint (2-7 months after hospital discharge). After hospital discharge, 62% of participants (n = 396) who were admitted for COVID-19 reported poor sleep quality via the Pittsburgh Sleep Quality Index questionnaire. A comparable 53% of patients (n = 338) felt their sleep quality had deteriorated after discharge, as assessed by the numerical rating scale.
These measurements were compared to an age-matched, sex-matched, BMI-matched, and time from discharge-matched UK Biobank cohort who had been recently hospitalized. Compared to the recently hospitalized matched UK Biobank cohort, participants in the CircCOVID study slept an average of 65 minutes longer, had a lower sleep regularity index (–19%), and had a lower sleep efficiency (3.83%). After comparing the primary study cohort to a nonhospitalized UK Biobank cohort, the investigators found similar results.
Overall sleep quality, deterioration in sleep quality after COVID-19 hospitalization, and sleep regularity were all associated with higher dyspnea scores. Notably, poor sleep quality, deteriorated sleep quality, and sleep regularity were also linked to impaired lung function. The investigators also found that anxiety mediated 18-39% of sleep disturbance’s effect on dyspnea, while muscle weakness mediated 27-41% of the dyspnea effect.
The study authors concluded that sleep disturbance after COVID-19 hospital admission is associated with dyspnea, anxiety, and muscle weakness. “Due to the association with multiple symptoms,” they wrote, “targeting sleep disturbance might be beneficial in treating the post-COVID-19 condition [long COVID].”