Physical Activity and Physical Function in Older Adults with Multiple Sclerosis

Background: There is a worldwide shift in the prevalence of multiple sclerosis (MS) among older adults (≥60 years of age). This cohort of older adults with MS undergoes the effects of aging along with a chronic, disabling neurological disease on physical activity, sedentary behavior, and physical function. The rate and pattern of participation in physical activity and sedentary behavior might be associated with a reduction of physical function among older adults with MS.

Objectives: This study examined the associations among levels of light and moderate-to-vigorous physical activity (LPA and MVPA), sedentary behavior, and physical function in older adults with MS. 

Methods: The sample included 40 older adults with MS (median age of 60 years). Participants wore an accelerometer during the waking hours of a 7-day period and the data were processed for time spent in MVPA, LPA, and sedentary behavior using cut-points for MS. Participants further completed 3 performance measures of physical function, namely the Short Physical Performance Battery (SBBP; lower extremity function), 6 minute walk (6MW; walking endurance), and the timed 25-foot walk (T25FW; walking speed). 

Results: Median scores for time spent in MVPA and LPA were lower and sedentary behavior was notably greater than reported for older adults in the general population. Bivariate correlation analyses indicated that LPA and MVPA were associated with SPPB (r’s =  .551 & .311, respectively), 6MW (r’s =  .660 & .529, respectively), and T25FW (r’s =  .623 & .403, respectively) scores, but were stronger for LPA. Regression analyses yielded significant associations between LPA, but not MVPA or sedentary behavior, with SPPB (β = .583), 6MW (β = .613), and T25FW (β = .627) scores. 

Conclusions: Collectively, our data indicated that older adults with MS who engaged in more LPA demonstrated better physical function independent of sedentary behavior and MVPA. Such results might underscore LPA as a suitable target of future rehabilitative interventions for improving physical function in older adults with MS.