No association between body composition and walking outcomes in multiple sclerosis

Abstract

BackgroundOne major concern of excess body weight is diminished physical function. The excess body weight associated with obesity can bring about challenges for physical function, particularly walking performance, among persons living with the consequences of a chronic, neurological disease. There is evidence that persons with multiple sclerosis (MS) have significantly reduced walking performance compared with controls; however, the relationship between body composition and walking outcomes has not been well-defined in persons with MS. To that end, the study examined the associations between body composition metrics and a comprehensive battery of walking outcomes in persons with MS recruited across a wide distribution of body mass index. MethodsAmbulatory participants with MS (n=64) underwent an assessment of neurological disability status using the Expanded Disability Status Scale (EDSS) and body composition metrics (i.e., percent body fat, fat mass, lean mass, bone mineral content and density) using dual-energy x-ray absorptiometry. Participants then completed the Timed 25-Foot Walk (T25FW), Timed Up and Go (TUG), 6-Minute Walk (6MW), and 12-Item Multiple Sclerosis Walking Scale (MSWS-12). We examined Spearman rank-order bivariate correlations among percent body fat, fat mass, lean mass, bone mineral content and density, T25FW, TUG, 6MW, MSWS-12, and EDSS. ResultsBody composition metrics were not significantly associated with T25FW (rs=-.11, .12), TUG (rs=-.04, .11), 6MW (rs=-.01, .20), and MSWS-12 (rs=-.16, .03). Of note, body composition metrics were not correlated with disability status based on EDSS (rs=-.11, .03). Body composition metrics were not associated with walking outcomes even after controlling for EDSS. ConclusionOur data indicated that worse body composition profiles are not necessarily associated with worse walking performance, greater perception of MS-related walking impairment, or more severe disability status in MS. Future research may consider examining other health-related or disease outcomes of overweight or obesity in MS. Overall, our findings suggest that optimization of body composition may not be a target of interventions for improving walking outcomes, and future research might explore other factors that influence lower physical function in MS.