Accelerometers May Help Modify Physical Activity, Sedentary Time in MS

Individuals with multiple sclerosis (MS) are more sedentary; partake in less light physical activity (LPA), partake in less moderate and vigorous physical activity (MVPA); perform fewer steps during free living activity; and generate a lower activity count compared with healthy individuals. These are the findings of a study published in the journal Multiple Sclerosis and Related Disorders.

Researchers sought to perform a systematic review of the literature on the objective evaluation of sedentary time, MVPA, LPA, step counts, and activity counts among individuals with MS vs healthy, matched control individuals. They also sought to provide quantitative data pooling to establish whether differences exist in the time spent in various domains of physical activity (PA) between patients with MS and healthy control individuals. The researchers’ analysis aimed to evaluate differences in accelerometer-measured sedentary behavior and PA between these 2 groups of individuals.

A systematic search of relevant databases was conducted from inception through November 22, 2019. For inclusion in the analysis, studies needed to fulfill the following criteria:

• Include a group of participants with a definite diagnosis of MS of any type
• Have ≥3 days of PA monitoring using an accelerometer during free living conditions
• Include age-matched healthy controls
• Evaluate adults >18 years of age
• Include data that were reported in a manner was suitable for quantitative pooling, including:
  • Percent of time spent sedentary
  • Minutes per day of sedentary time, LVA, and MVPA
  • Steps per day
  • Counts per day

The initial literature search yielded a total of 9021 papers. Following application of inclusion criteria, 21 eligible papers were ultimately included in the study. One of the papers was a longitudinal study from which only baseline data were included. Another paper was a reliability and validity study, with data regarding individuals with MS vs controls included in the validity section.

All of the other papers were cross-sectional in design, with one of them being a pilot study and another being a randomized, controlled study. One of the papers used 2 devices in unison, with only one set of data included in the statistics. Outcomes data were available for 1098 participants — 579 of whom were patients with MS and 519 of whom were healthy control individuals.

In the meta-analysis, significant differences were evident in all of the categories evaluated:

• Sedentary time (minutes per day): standard mean difference (SMD), –0.286; P =.044; n=4 studies
• Relative sedentary time (% per day): SMD, –0.646; P =.000; n=5 studies
• LPA (minutes per day): SMD, 0.337; P =.039; n=5 studies
• Relative LPA (% per day): SMD, 0.211; P =.152; n= 1 study
• MVPA (minutes per day): SMD, 0.801; P =.000; n=8 studies
• Relative MVPA (% per day): SMD, 0.914; P =.000; n= 5 studies
• Step count: SMD, 0.894; P =.000; n=8 studies
• Activity count: SMD, 0.693; P =.000; n=13 studies

Several limitations in the study warrant mention. Although every attempt was made to include all relevant studies, only those papers written in English were included in the analysis. Thus, it is possible that papers from databases that indexed nonEnglish articles may have been missed. Further, because 7 of the 21 studies were affiliated with the same research department, it is difficult to determine whether the same participants were involved in multiple studies, which would reduce the scope of individuals with MS involved in the meta-analysis. Additionally, many of the studies explored used accelerometer output as their secondary analysis, with the main aims of the study being different areas of PA.

According to the researchers, this is the first review to assess accelerometer measure between patients with MS and healthy controls evaluated during the same testing period. They believe that “Future studies may benefit from a greater focus on reducing sedentary time and seek to include more participants with progressive forms of MS or with higher levels of EDSS [Expanded Disability Status Scale].”

The researchers concluded, “More interventions should be aimed at helping those who struggle to be active without guidance and support due to mobility, emotional or cognitive issues, especially with advances in technology.”