Sleep and circadian rhythm alterations in myalgic encephalomyelitis/chronic fatigue syndrome and post-COVID fatigue syndrome and its association with cardiovascular risk factors: A prospective cohort study. — ME/CFS Atlas
Sleep and circadian rhythm alterations in myalgic encephalomyelitis/chronic fatigue syndrome and post-COVID fatigue syndrome and its association with cardiovascular risk factors: A prospective cohort study.
Zerón-Rugerio, María Fernanda, Zaragozá, Maria Cleofé, Domingo, Joan Carles et al. · Chronobiology international · 2024 · DOI
Quick Summary
This study looked at sleep patterns and daily body rhythms in ME/CFS patients and compared them to healthy people. Researchers found that ME/CFS patients had lower activity levels, worse sleep quality, and unhealthy cholesterol levels compared to healthy controls. The study also found that problems with blood vessel function may connect sleep disruptions to heart health problems in ME/CFS patients.
Why It Matters
This study provides objective evidence that sleep and circadian rhythm disturbances in ME/CFS are associated with measurable cardiovascular risk factors and endothelial dysfunction. Understanding these connections may help explain why ME/CFS patients experience fatigue and inform future interventions targeting both circadian health and cardiovascular risk. The findings also extend understanding to post-COVID ME/CFS, suggesting shared pathophysiological mechanisms.
Observed Findings
ME/CFS patients showed significantly lower motor activity levels compared to healthy controls.
ME/CFS patients demonstrated worse objective sleep quality on actigraphy compared to controls.
ME/CFS patients had a worse lipid profile (higher cholesterol/lipid abnormalities) than matched healthy controls.
Circadian temperature rhythm disturbances were associated with lipid profile abnormalities in patients.
Endothelin-1 and VCAM-1 levels were significantly elevated in ME/CFS patients compared to controls.
Inferred Conclusions
Lipid profile abnormalities in ME/CFS are linked to disrupted circadian rhythms and sleep dysfunction rather than following standard metabolic patterns.
Endothelial dysfunction may serve as a mechanistic link between circadian/sleep disruption and cardiovascular risk in ME/CFS.
Post-COVID ME/CFS and primary ME/CFS share similar circadian and sleep disturbances, suggesting overlapping pathophysiology.
The relationship between sleep, circadian rhythms, and cardiovascular health in ME/CFS is complex and involves multiple dysfunctional pathways.
Remaining Questions
Does correcting circadian rhythm disturbances improve lipid profiles and endothelial function in ME/CFS patients?
What This Study Does Not Prove
This study does not establish causation—it is unclear whether circadian disruption causes cardiovascular dysfunction or vice versa. The small sample size and reliance on self-reported outcome measures for some variables limit generalizability. The cross-sectional nature of many analyses prevents determining whether these associations precede ME/CFS onset or develop as a consequence of the illness.
About the PEM badge: “PEM required” means post-exertional malaise was an explicit required diagnostic criterion for participant inclusion in this study — not that PEM was studied, observed, or discussed. Studies using criteria that do not require PEM (e.g. Fukuda, Oxford) are tagged “PEM not required”. How the atlas works →