Fatigue Severity and Sleep Disorders Among Patients With Multiple Sclerosis: A Cross-sectional Study From Iran

Background: Multiple sclerosis (MS) is the most prevalent autoimmune chronic disease globally. The current study was conducted to determine the relationship between fatigue severity and circadian rhythm sleep disorders among Iranian MS patients.  Methods: The statistical population of this cross-sectional study included MS patients who were members of the MS Association in Khorramabad City, southwestern Iran. The sample size included 64 MS patients who met the inclusion criteria for the study and were selected through a simple random method. The study data were collected using a demographic questionnaire, fatigue severity scale (FSS), and Pittsburgh sleep quality index (PSQI). The obtained data were analyzed using SPSS-18 software through the independent t test and Pearson correlation test. The significance level was considered to be < 0.05.  Results: Fatigue severity of 53% and 47% of studied patients were severe and weak, respectively. The mean scores of men's fatigue severity and sleep disorders were significantly more than women's (P=0.01, P=0.03, respectively). The Pearson correlation coefficient between circadian rhythm sleep disorders and fatigue severity scores was 0.33, which was significant (P= 0.008).  Conclusions: Sleep disorders and fatigue severity in the studied patients can be outcomes of MS or whether there is a cause-and-effect relationship between them. So, the sleep disorder aggravates the fatigue severity. If this relationship is confirmed in a randomized clinical trial, it can help reduce the fatigue severity in MS patients by treating sleep disorders.