Results from a study examining sleep health in individuals with multiple sclerosis (MS) demonstrated that 76% of participants measured in extreme ranges for at least 2 of 7 sleep domains. Poor sleep quality affected 45% of participants, abnormal sleep timing affected 35%, and pathological daytime sleepiness affected 33%.
Investigators calculated median values of 456.3 minutes (nearly 8 hours) for total sleep time and 37 minutes for time spent awake following sleep onset. The individuals with MS had longer sleep duration with decreased sleep regularity compared with a historical cohort of older men without MS.
The domains associated with depressive symptoms included increased daytime sleepiness, poor sleep quality, and a higher composite sleep health score. Lower sleep rhythmicity was associated with higher fatigue levels. The domains associated with cognitive impairment included shorter sleep duration, poor quality, lower rhythmicity, lack of sleep continuity, and a higher composite sleep health score.
“A unified multidimensional sleep metric could offer new opportunities for consistent and in-depth evaluation of sleep in [patients with] MS,” the authors said. “These findings have laid important groundwork regarding the link between sleep and MS symptoms that warrant further study with the use of consistent and comprehensive approaches,” they wrote, and suggested that future research on this topic may assist in developing targeted sleep treatments to reduce sleep-related MS symptoms.
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The researchers collected data from a 2016 study by Braley et al from 49 of 57 recruited people with MS, analyzing 7 sleep domains: sleep duration, continuity, timing, quality, regularity, sleepiness, and rhythmicity. The investigators used wrist-worn accelerometry, the Pittsburgh Sleep Quality Index, and the Epworth Sleepiness Scale to estimate these 7 domains. They used previously established guidelines to determine values outside the normally accepted range, calculating composite sleep health scores of extreme values for each participant.
The investigators analyzed the relationships between sleep domains and severity of MS symptoms, including pain, fatigue, depression, and cognitive impairments. They assessed pain intensity using the Patient Reported Outcomes Measurement Information System-29, fatigue using the Fatigue Severity Scale, depressive symptoms using the Patient Health Questionnaire-9, and cognitive impairment using the Minimal Assessment of Cognitive Function in MS.
Limitations of this study included the small sample size, lack of inclusion of frequency and duration of daytime napping in the framework, and potential omission within the existing framework of important variables affecting overall sleep phenotype. The investigators also did not adjust for obstructive sleep apnea, which was present in 27 of the 49 people with MS, or for use of sleep, pain, or depression medications.
Whibley D, Goldstein C, Kratz AL, Braley TJ. A multidimensional approach to sleep health in multiple sclerosis. Mult Scler Relat Disord. 2021;56:103271. doi:10.1016/j.msard.2021.103271