Replication data for autonomic dysfunction and circadian rhythm in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (CircaME study)

Myalgic Encephalomyelitis, also known as Chronic Fatigue Syndrome (ME/CFS), is a debilitating multisystem illness characterized by persistent fatigue, post-exertional malaise, and cognitive dysfunction among other cardinal symptoms. A high percentage of cases result in work disability in adults and academic failure in adolescents. ME/CFS is also characterized by symptoms secondary to cardiovascular dysautonomia, demonstrating autonomic nervous system (ANS) dysfunction. Sleep-wake cycle disturbances and motor activity abnormalities have also been observed. Given the close link between the regulation of the ANS balance (sympathetic/parasympathetic) and the circadian system, the starting hypothesis of this work is that alterations in circadian rhythms, especially those measured by peripheral temperature, physical activity, light exposure, and urinary melatonin levels, could be used as a tool in the assessment of symptoms and therapeutic targets in ME/CFS. Consequently, individualized strategies for the appropriate restructuring of autonomic function and circadian rhythmicity would help improve symptoms and quality of life in these patients.