Moderate-to-vigorous physical activity is associated with cognitive processing speed in patients with multiple sclerosis (MS), according to study findings published in Multiple Sclerosis and Related Disorders.
Patients with MS often have cognitive impairment that presents as slowed cognitive processing speed and impaired learning and memory. Currently, there are no Food and Drug Administration (FDA)-approved treatments. Management options include free-living physical activity. Studies have indicated physical activity measured by steps/day is associated with cognition in individuals with MS, but prior studies have not prescreened participants for presence of impaired cognition.
In the current study, researchers utilized several free-living physical activity metrics to analyze a prescreened sample from an earlier double-blind, placebo-controlled, randomized trial.
The researchers administered the Symbol Digit Modalities Test (SDMT), California Verbal Learning Test-II (CVLT-II), and the Brief Visiospatial Memory Test-Revised (BVMT-R) to 60 adult patients (mean 49.5 years; 48 women; 88.3% White; 48 with relapsing remitting MS) at a tertiary MS care center in New York. They measured free-living physical activity with accelerometers for 1 week.
The individuals participated in 14.9±16.0 minutes of moderate-to-vigorous physical activity per day, 248.8±92.7 minutes of lighter physical activity per day, and 552.8±121.6 minutes of sedentary behavior per day. The group had an average of 4708 daily steps. Cognitive impairment presented as SDMT scores (39.5±11.5), CVLT-II scores (47.1±12.2), and BVMT-R (17.3±7.1).
Researchers analyzed the data with bivariate and partial Spearman rank-order correlations. They corrected for age, sex, years of education, and disability, based on Expanded Disability Status Scale (EDSS) scores.
Moderate-to-vigorous physical activity had a moderate-to-large association with SDMT, CVLT-II, and BVMT-R scores. Lighter physical activity was moderately correlated with SDMT scores. Sedentary behavior did not significantly impact cognitive outcomes. Steps/day had moderate-to-large association with SDMT and BMT-R scores.
Moderate-to-vigorous physical activity and steps/day were each moderately correlated with SDMT, after controlling for demographic and clinical covariates.
Study limitations included inability to infer causation, ability to include other outcomes for examining brain substrates of the associations, and generalization to other demographic populations.
“Collectively, the present study provided novel evidence of statistically significant associations between device-measured MVPA [moderate-to-vigorous physical activity] and steps/day with CPS, independent of age, sex, education, and disability status, among persons with MS who demonstrate objective cognitive impairment,” the researchers concluded.
Motl RW, Sandroff BM, Benedict RHB. Moderate-to-vigorous physical activity is associated with processing speed, but not learning and memory, in cognitively impaired persons with multiple sclerosis. Multiple Sclerosis Related Disorders. Published online April 26, 2022. doi: 10.1016/j.msard.2022.103833