‘Underlying mechanisms remain unclear’
Amitava Banerjee, MD, professor of clinical data science and honorary consultant cardiologist, Institute of Health Informatics, UCL, London, welcomed the study but noted that it did not include nonhospitalized post-COVID patients.
“The majority of people with long COVID were not hospitalized for COVID, so the results may not be generalizable to this larger group,” she said in an interview. “Good-quality sleep is important for health and reduces risk of chronic diseases; quality of sleep is therefore likely to be important for those with long COVID in reducing their risk of chronic disease, but the role of sleep in the mechanism of long COVID needs further research.”
In a commentary also published in The Lancet Respiratory Medicine, W. Cameron McGuire, MD, pulmonary and critical care specialist from San Diego, California, and colleagues wrote: “These findings suggest that sleep disturbance, dyspnea, and anxiety are common after COVID-19 and are associated with one another, although the underlying mechanisms remain unclear.”
The commentators “applauded” the work overall but noted that the findings represent correlation rather than causation. “It is unclear whether sleep disturbance is causing anxiety or whether anxiety is contributing to poor sleep. ... For the sleep disturbances, increased BMI in the cohort reporting poor sleep, compared with those reporting good sleep might suggest underlying obstructive sleep apnea,” they wrote.
Dr. McGuire and colleagues added that many questions remain for researchers and clinicians, including “whether anxiety and dyspnoea are contributing to a low arousal threshold [disrupting sleep] ... whether the observed abnormalities (e.g., in dyspnea score) are clinically significant,” and “whether therapies such as glucocorticoids, anticoagulants, or previous vaccinations mitigate the observed abnormalities during COVID-19 recovery.”
Dr. Blaikley has received support to his institute from an MRC Transition Fellowship, Asthma + Lung UK, NIHR Manchester BRC, and UKRI; grants to his institution from the Small Business Research Initiative Home Spirometer and the National Institute of Academic Anaesthesia; and support from TEVA and Therakos for attending meetings. He is a committee member of the Royal Society of Medicine. A coauthor received funding from the National Institutes of Health and income for medical education from Zoll, Livanova, Jazz, and Eli Lilly. Dr. Banerjee is the chief investigator of STIMULATE-ICP (an NIHR-funded study) and has received research funding from AstraZeneca.
A version of this article first appeared on Medscape.com.