TOPLINE:

A decline in daytime physical activity, as detected with wearable accelerometers, was associated with increased risk for clinical disability and brain atrophy in patients with multiple sclerosis (MS), a new cohort study showed.

METHODOLOGY:

• A longitudinal cohort analysis, conducted between 2021 and 2023, included more than 200 patients aged 40 years or older (mean age, 55 years; 71% women; 77% White individuals) who had MS for an average of 13.2 years and a median baseline score of 3.0 on the Expanded Disability Status Scale (EDSS).
• Patients included those with stable relapsing-remitting MS with no evidence of progression, confirmed progressive MS with sustained disability worsening on the EDSS, and relapsing-remitting MS with suspected clinical progression but no sustained disability worsening.
• Patients wore an accelerometer on their nondominant wrist for 24 hours daily for approximately 2 weeks every 3 months over 3 years. The accelerometers measured total and 2-hour specific activities, sedentary time, and circadian rhythm parameters, such as moderate-to-vigorous physical activity, daytime activity ratio, and active-to-sedentary transition probability.
• The primary clinical disability outcome was EDSS+, defined as confirmed worsening on EDSS or sustained 20% worsening on specific tests confirmed at least 6 months later. Brain MRI was additionally conducted at baseline and in year 2.

TAKEAWAY:

• 120 participants experienced EDSS+ events over an average of 2.9 years. Total activity counts declined by an average of 2% per year (P = 1.11 × 10^-⁷). One-SD decreases in within-person activity from 8 AM to 10 AM, 10 AM to 12 PM, and 12 PM to 2 PM were associated with hazard ratios (HRs) of 1.20, 1.24, and 1.23, respectively, for confirmed disability progression by EDSS+.
• One-SD decreases in moderate-to-vigorous physical activity and daytime activity ratio were associated with increased risk for EDSS+ (HRs, 1.25 and 1.26, respectively), whereas a 1-SD decrease in active-to-sedentary transition probability was associated with a 14% lower risk for progression (HR, 0.86).
• A 1-SD decreases in total activity counts from 8 AM to 10 AM was associated with 0.18% lower whole-brain volume, 0.34% lower deep gray matter volume, and 0.35% lower thalamic volume over time.
• Lower mean moderate-to-vigorous physical activity levels were associated with a 0.94% lower whole brain volume, 1.43% lower deep gray matter volume, and 1.78% lower thalamic volume over time.

IN PRACTICE:

“More research is needed to confirm these findings, but it’s exciting to think that using easily accessible devices could help us predict who is at risk of worsening disease and potentially prevent those changes,” study investigator Ellen M. Mowry, MD, John Hopkins School of Medicine, Baltimore, said in a press release.

The authors of an accompanying editorial added that “adherence to this technology was markedly high, in line with another longitudinal study on a wrist-worn wearable device, indicating high potential for clinical implementation.”

SOURCE:

The study was led by Kathryn C. Fitzgerald, ScD, Johns Hopkins School of Medicine. The accompanying editorial was led by Daan J. de Jong, MS Center Amsterdam, Amsterdam UMC, Amsterdam, Netherlands. Both papers were published online on March 4 in Neurology.

LIMITATIONS:

The study had a relatively short follow-up period for MRI assessments, and ascertainment bias may have affected the initial groupings. The cohort also lacked a longitudinal comparison group of healthy controls to assess how accelerometry measures change with normal aging; and the relatively older, more disabled population limited the findings’ generalizability to patients with early MS and lower levels of disability. Additionally, low event rates for some EDSS+ component tests prevented the explicit linking of accelerometry measures with each component. 

DISCLOSURES:

This study was funded by the National Institutes of Health. Three of the 13 investigators reported having financial or other ties with various sources and one of the editorialists reported serving on editorial boards of several journals and receiving research support from various sources, all of which are fully listed in the original article. The other editorialist and investigators reported having no relevant financial relationships.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.