Pandemic-disordered sleep: longer illness and more fatigue but little SARS-CoV-2 effect

The COVID-19 pandemic disturbed sleep globally in both infected and uninfected individuals. Prolonged symptoms (particularly fatigue) after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection (post-COVID 2019 syndrome (PCS)) remain a health issue. Whether there is a relationship between PCS and sleep disturbance is largely unknown, with most studies lacking uninfected controls. We assessed sleep behaviours in a large UK cohort, analysing sleep disruption, fatigue, SARS-CoV-2 infection and symptom duration.

UK adults previously recruited from the King's College London ZOE COVID Symptom Study to the COVID Symptom Study Biobank, with prospective symptom logging and SARS-CoV-2 testing, were invited to complete online validated questionnaires for sleep (Pittsburgh Sleep Quality Index, Sleep Condition Indicator, the STOP-Bang Questionnaire and Epworth Sleepiness Scale), fatigue (Chalder Fatigue Scale) and mental health (Generalised Anxiety Disorder 2 scale and Patient Health Questionnaire 2). Data were analysed considering SARS-CoV-2 infection, symptom duration and co-morbidities, including mental health.

Questionnaires were completed by 3833 of 8355 participants (2089 infected, 1721 uninfected, 23 unknown). Individuals with longer (versus shorter) symptom duration had poorer sleep scores for multiple questionnaires, but SARS-CoV-2 infection had no independent effect on sleep. However, previously infected (versus uninfected) individuals had greater fatigue, over a year since infection. Longer symptom duration, poorer sleep scores and greater fatigue were also associated with higher contemporaneous levels of anxiety and depression; however, an independent effect of prior SARS-CoV-2 infection on fatigue remained after adjustment. Higher body mass index, greater age and prior co-morbidities also independently worsened sleep scores.

Sleep disturbance contributes to prolonged symptom reporting, irrespective of SARS-CoV-2 infection. Proven sleep interventions may help individuals with post-pandemic fatigue, including PCS.