Meeting Physical Activity Guideline Criteria in a Sample of People with MS and Cognitive Processing Speed Impairment

Background: Cognitive impairment affects over half of persons diagnosed with MS. It is commonly under-diagnosed and difficult to treat, as few effective therapies exist to manage this debilitating condition. Greater physical activity (PA) has been linked to better cognitive performance in both healthy and cognitively impaired elders. A growing body of evidence exists to support a comparable linkage between PA and cognitive functioning in persons with MS, a population noted to be physically inactive. Validated methods to quantify PA in persons with MS (e.g., Godin Leisure-Time Exercise Questionnaire (GLTEQ) and accelerometers) can provide data to examine whether individuals meet PA criteria established for adults or specific to persons with MS. 

Objectives: To examine patterns of PA in a sample of people with MS and impaired processing speed (defined as SDMT scores < 56) using three criteria for assessing MVPA: GLTEQ, 2008 PA Guidelines for Adults, and Canadian PA Guidelines for Adults with MS.  

Methods: The sample included 16 persons with MS and impaired processing speed enrolled in a 6-month intervention study. Participants completed the GLTEQ and wore an ActiGraph GT3X accelerometer for seven consecutive days during waking hours at baseline, 3-months, and 6-months. GLTEQ data was used to compute minutes/day of ‘moderately active’ and ‘active’ PA based on published criteria. Accelerometer activity counts > 600 minutes/day were used to compute minutes of MVPA/day, which was compared to both the 2008 and MS-specific PA guidelines.

Results: Sample characteristics (n=16): mean age 45.6 + 9.1; mean MS duration 11.5 + 8.3; mean years of education 16.6 + 2.6 years; mean SDMT raw score 41.7 + 10.0; 69% female; 81% White; 19% Black; 19% Hispanic; 81% relapsing-remitting MS; 6% secondary progressive MS; 13% primary progressive MS; 50% employed full or part-time and 25% unemployed due to disability. There were great differences among the number of participants meeting self-report PA criteria and accelerometer-derived PA criteria. 

Conclusions: The pattern of PA among this sample of persons with MS and cognitive impairment differed depending on the criteria used. This underscores the need for future research investigating the question raised by Motl et al. (2015), What is the optimal measurement of PA in people with MS?

Acknowledgment: This project was supported by grants from the International Organization of MS Nurses and NIH, NINR (Grant F31NR014601)