Associations between fatigue impact and lifestyle factors in people with multiple sclerosis - The Danish MS hospitals rehabilitation study.

Abstract Background: The lack of medical treatment options to reduce fatigue in patients with multiple sclerosis (MS) emphasize the importance of identifying potential non-pharmacological modifiable factors, as this may help advance current treatment strategies. The aim of this study was to identify potential modifiable lifestyle factors as well as patient- and disease-related characteristics, that are associated with fatigue in a large sample of clinically well-characterized patients with MS. Methods: This study was a secondary analysis of a pragmatic randomized controlled trial of inpatient multidisciplinary rehabilitation in Denmark. MS patients aged 18 to 65 years and with a disease severity score ≤ 7.5 according to the Expanded Disability Status Scale participated. Data on patient- and disease-related characteristics, fatigue impact (Modified Fatigue Impact Scale (MFIS)), and on lifestyle factors (tobacco smoking, alcohol intake, and physical activity), were collected at baseline. A linear mixed model was used to compare MFIS total, physical, cognitive, and psychosocial scores across subgroups of selected characteristics. Regression analyses were used to examine associations between lifestyle factors and MFIS total, physical, cognitive, and psychosocial scores. Results: In the sample of 417 MS patients, median age was 51 years, 69% were female, median time since diagnosis was 8 years, with 41% having relapsing remitting MS. Higher MFIS total scores were observed in MS patients with shorter time since diagnosis, being a tobacco smoker, and not undertaking regular physical activity. Somewhat similar findings were observed for MFIS subscores (physical, cognitive, psychosocial), especially MFIS physical scores. In the multivariate analyses, physical activity was significantly associated with fatigue impact on total, physical and psychosocial functioning. Tobacco smoking was significantly associated with fatigue impact on psychosocial functioning. Alcohol intake was not associated with fatigue impact. None of the lifestyle factors were associated with fatigue impact on cognitive functioning. In the adjusted models time since diagnosis was significantly associated with fatigue impact on total, physical and cognitive functioning, as was disease severity with fatigue impact on physical and cognitive functioning. Conclusion: Physical activity showed the most pronounced associations with fatigue impact on physical and psychosocial functioning, while the impact on cognitive functioning showed a trend. Tobacco smoking contributed significantly to impact on psychosocial functioning, while alcohol intake did not contribute to fatigue impact. Introducing or supporting maintenance of physical activity/exercise and cessation of tobacco smoking seems to be a useful approach for rehabilitation services to help patients with MS manage fatigue.