Physical Activity and Life Stress Are Associated With Illness Intrusiveness in Persons With Multiple Sclerosis.

Abstract

To explore which modifiable lifestyle behaviors contribute to illness intrusiveness in persons with multiple sclerosis (MS). Cohort study. Community-based comprehensive MS center. Adults with MS (N=154) who completed an online battery of self-report questionnaires. Not applicable. Illness intrusiveness was measured with the 13-item Illness Intrusiveness Ratings Scale. Lifestyle behaviors were measured using the respective components of the Simple Lifestyle Indicator Questionnaire (ie, Diet, Physical Activity, Alcohol, Smoking, and Life Stress) and self-reported body mass index (BMI). After controlling for age, race, sex, disease duration, and level of physical disability ("disability"), life stress was associated with greater illness intrusiveness (b=4.65, P<.001), and physical activity was associated with less illness intrusiveness (b=-0.67, P=.009). Exploratory mediation analyses revealed physical activity had an indirect effect on illness intrusiveness through disability (b=-0.39, 95% CI: -0.68, -0.16). Conversely, disability also displayed an indirect effect on illness intrusiveness through physical activity (b=0.57, 95% CI: 0.12, 1.16). Life stress and physical activity are 2 modifiable lifestyle behaviors that contribute to illness intrusiveness, with the latter also having an indirect effect through disability. These findings may help inform future behavioral interventions for improving health-related quality of life in persons with MS.