Modifiable Lifestyle Characteristics and Mental Health Status in a Large Cohort of People with Multiple Sclerosis

Background: Low physical activity, smoking, obesity and poor diet are potentially modifiable contributors to poor mental and physical functioning in people with multiple sclerosis (pwMS). Often, these lifestyle characteristics tend to cluster; however, it is unknown whether having multiple suboptimal health behaviors is associated with greater mental health disease burden among pwMS.

Objectives: To characterize the prevalence of co-occurring suboptimal lifestyle characteristics in a large survey of pwMS and assess their association with MS symptoms.

Methods: In 2015 we conducted a cross-sectional study of the North American Research Committee on MS (NARCOMS) registry participants who provided their clinical and demographic characteristics including information on diet, height and weight (from which body mass index [BMI] was calculated), leisure-time physical activity and smoking status. We classified the lifestyle characteristics as sub-optimal if a person: was a smoker, did not participate in leisure-time physical activity, was obese (BMI ≥30), or was in lowest 20% of diet quality (low intake of fruits, vegetables, whole grains; high sugar, red meat intake). We assessed the association between the four lifestyle characteristics and severity of MS symptoms including depression, fatigue and cognition using multivariable adjusted multinomial models.

Results: Of the 7418 (68%) responders, roughly 43% reported no sub-optimal health behaviors on any of the four lifestyle characteristics; however, 36% reported one, 17% reported two, 4% reported three suboptimal characteristics, and 0.5% reported all four. The most common combination of suboptimal characteristics was obesity and a lack of physical activity, with a prevalence of 11%. After adjusting for disability status, gender and disease duration, participants with at least two suboptimal lifestyle characteristics were more likely to report severe depression (odds ratio [OR] for severe vs. mild: 2.04; 95% CI:1.72-2.44), fatigue (OR for severe vs. mild: 1.75, 95% CI: 1.57-1.91), or problems with cognition (OR for severe vs. mild: 1.57; 95% CI: 1.32-1.88).

Conclusions: Our large cross-sectional survey suggests that suboptimal, but modifiable, lifestyle characteristics tend to co-occur and are associated with substantially worse self-reported depression, cognition and fatigue. Longitudinal studies are needed to assess whether lifestyle characteristics are associated with changes in mental health status among pwMS.