A new study investigated the influence of sleep disturbance, fatigue and disability on the quality of life (QOL) in multiple sclerosis (MS) patients.
Health-related QOL measurements are important tools for assessing the impact of a disease on self-reported physical, mental, emotional, and social functioning. Most studies show that QOL is not related to the degree of disability while fatigue is often cited as one of the troublesome symptoms.
Around 53%–90% of MS patients report chronic fatigue, and an additional 54% suffer from disturbed sleep. Considering the effect sleep disorders have on comorbid conditions such as heart disease, obesity, and diabetes, investigating the causes of sleep disturbance in MS should be a priority. However, while it is generally acknowledged that good sleep quality is a crucial factor for health, few studies have investigated the effect of sleep, fatigue, and disability for QOL.
The study — “Fatigue, Sleep Quality, and Disability in Relation to Quality of Life in Multiple Sclerosis,“ published in the International Journal of MS Care by Fatemeh Moghaddam Tabrizi and Moloud Radfar from the Urmia University of Medical Sciences, Iran — enrolled 217 patients from an outpatient clinic. Sleep quality, fatigue severity, disability, and quality of life were assessed using a number of questionnaires.
Researchers found that sleep quality and fatigue had a strong impact on QOL, both physical and mental. The authors could also observe a correlation between the subscales of QOL measuring physical and mental QOL — a result likely indicating that mental QOL decreases following a decreased physical QOL.
The study also noticed an association between sleep quality and fatigue. In addition to the obvious explanation, that sleepiness due to sleep disorders can be perceived as fatigue, a lack of sleep may also induce a feeling of fatigue by increasing levels of inflammatory cytokines, which are immune signaling molecules.
The team also found an association between the level of disability and QOL, although the patients included in the study had relatively low levels of neurological disability. The results showed that both physical and mental QOL are affected soon after disease onset. Also, the level of disability was related to fatigue, but not to sleep quality.
The present study clearly showed the importance of screening for fatigue and sleep disturbance in MS patients. Since sleep disorders have a profound effect on both QOL and other health-related factors, and are potentially treatable, the authors argue that early intervention could be beneficial. While such interventions might improve QOL in MS patients, more research is needed to understand the causes of sleep disturbance in MS.