Association between frailty and free-living walking performance in people with multiple sclerosis

Item Type:	Article
Title:	Association between frailty and free-living walking performance in people with multiple sclerosis
Creators Name:	Zanotto, T. and Galperin, I. and Mirelman, A. and Chen, L. and Regev, K. and Karni, A. and Schmitz-Hübsch, T. and Paul, F. and Lynch, S.G. and Akinwuntan, A.E. and Devos, H. and Hausdorff, J.M. and Sosnoff, J.J.
Abstract:	OBJECTIVE: The purpose of this study was to examine the association between frailty and the quantity and quality of free-living walking and the mediating effect of frailty on the relationship between disability and walking performance in people with multiple sclerosis (MS). METHODS: Ninety-nine people with relapsing–remitting MS (mean age = 49.3 [SD = 9.8] y; 73.7% women; Expanded Disability Status Scale score range = 2.0–6.0) wore a triaxial accelerometer for 7 days. Recorded measures reflected the quantity (daily step counts, number of 30-second walking bouts, and signal vector magnitude) and quality (gait speed, step cadence, step and stride regularity, and sample entropy) of walking. For each walking quality measure, the typical (median), best (90th percentile), and worst (10th percentile) values were calculated. Frailty was evaluated through a 38-item frailty index. RESULTS: Participants were classified as not frail (n = 31), moderately frail (n = 34), and severely frail (n = 34) on the basis of established procedures. Patients who were moderately and severely frail exhibited poorer performance in all measures of walking quantity and quality, except for sample entropy, than individuals who were not frail. No differences in free-living walking performance were observed between the moderately and severely frail groups. Frailty did not mediate the relationship between disability (Expanded Disability Status Scale) and measures of walking quality. Conversely, frailty had a significant mediating effect on the relationship between disability and measures of walking quantity, such as daily step counts (indirect effect: b = −220.42, 95% CI = −452.03 to −19.65) and signal vector magnitude (indirect effect: b = −1.00, 95% CI = −1.86 to −0.30). CONCLUSIONS: Frailty is associated with poorer free-living walking performance in people with MS. The study findings suggest that frailty, rather than disability, may be primarily responsible for the lower amount of physical activity performed by people with MS in the real world. IMPACT: The observation that frailty and disability are differently related to measures of walking quality and quantity underscores the importance of a targeted approach to rehabilitation in people with MS.
Keywords:	Exercise, Frail Elderly, Frailty, Multiple Sclerosis, Relapsing-Remitting Multiple Sclerosis, Walking
Source:	Physical Therapy
ISSN:	0031-9023
Publisher:	Oxford University Press
Volume:	103
Number:	5
Page Range:	pzad032
Date:	May 2023
Official Publication:	https://doi.org/10.1093/ptj/pzad032
PubMed:	View item in PubMed

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