Sleep and circadian rhythm alterations in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and Post-COVID-19 syndrome and its association with cardiovascular risk factors: a prospective cohort study

Abstract

This study aimed to investigate circadian rhythm manifestations in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) patients (including a subpopulation of long-COVID patients) and healthy controls, while also exploring their association with cardiovascular health variables. 31 ME/CFS patients (75% females), 23 individuals diagnosed with post-COVID ME/CFS (56% females) and 31 matched healthy controls (68% females) were enrolled in this study. Demographic and clinical characteristics were assessed using validated self-reported outcome measures. Actigraphy data, collected over one week, were used to analyze the 24-hour profiles of wrist temperature, motor activity, and sleep circadian variables in the study participants. Associations between lipid profile with endothelial dysfunction biomarkers, such as endothelin-1, ICAM-1 and VCAM-1, and with sleep and circadian variables were studied. No differences were found in the variables between the two group of patients. Patients showed lower activity and worse sleep quality than matched healthy controls, together with a worse lipidic profile than controls, that was associated with disturbances in the circadian temperature rhythm. ICAM-1 levels were associated with plasma lipids in controls, but not in patients, who showed higher levels of VCAM-1 and endothelin-1. These findings suggest that lipid profiles in ME/CFS are linked to disrupted circadian rhythms and sleep patterns, likely due to endothelial dysfunction. Furthermore, they highlight the intricate relationship between sleep, circadian rhythms, and cardiovascular health in this condition.