Focusing on post-COVID syndrome fatigue

More than 100 million people worldwide have been infected by SARS-CoV-2 virus, the virus responsible for the acute disease COVID-19. Multiple studies have shown how various symptoms in these patients can persist for several months after resolution of the acute process, a phenomenon known as post-COVID syndrome. Neurological symptoms are varied, but the great majority of patients present fatigue.

To analyse post-COVID fatigue.

We present a prospective, single-centre, case-control study comparing patients with fatigue in the context of post-COVID syndrome with patients with history of COVID-19 but without post-COVID fatigue. Data were recorded at baseline (April 2021) and at 6 months. Data were recorded on clinical variables, fatigue questionnaires, sleep disorders, depression, anxiety, cognitive impairment, and quality of life. Basic laboratory analysis was performed with blood samples collected at the 2 visits. In addition, a substudy of proinflammatory (IL-6, IL-1β, TNF-α) and anti-inflammatory (IL-10) cytokines was performed.

Fatigue as measured by the Chalder Fatigue Scale was mixed (physical and psychological) and of moderate intensity. At 6 months, physical fatigue improved, but psychological fatigue did not. Significant differences were found in sleepiness, cognitive impairment, anxiety, and quality of life. Significant alterations were observed in TNF-α levels, but not in the remaining cytokines.

Patients with fatigue presented a poorer quality of life, with an improvement being observed at 6 months, which suggests a course that may be self-limiting; however, this will have to be confirmed with longer studies.