Comorbid Conditions and Physical Function in Adults With Multiple Sclerosis.

OBJECTIVE: We examined the total number of comorbid conditions as a correlate of physical function in persons with multiple sclerosis (MS). We further identified the presence of common comorbid conditions and examined physical function outcomes based on presence or absence of the comorbid conditions in persons with MS. DESIGN: Cross-sectional, comparative study. SETTING: University-based laboratory. PARTICIPANTS: Two hundred seven persons with MS (N=207) completed the study. MAIN OUTCOME MEASURES: Participants provided demographic, clinical, and comorbidity information. Participants then completed the 6-minute walk (6MW), timed 25-foot walk (T25FW), timed Up and Go (TUG), and short physical performance battery (SPPB). INTERVENTIONS: Not applicable. RESULTS: The number of comorbid conditions was associated with 6MW, T25FW, TUG, and SPPB scores (all P≤.001). Persons with MS who had hypertension performed worse on the 6MW, T25FW, TUG, and SPPB than persons without hypertension. Persons who had osteoarthritis performed worse on the 6MW, T25FW, and SPPB than persons without osteoarthritis. CONCLUSIONS: The results demonstrate that persons who report more comorbid conditions have worse physical function, and this may largely be associated with hypertension or osteoarthritis. There are opportunities for the design of behavioral interventions that target physical activity and/or diet for improving physical function via comorbid conditions in persons with MS.

Cross-sectional, comparative study of health-related quality of life across the adult lifespan in multiple sclerosis.

PURPOSE: This study examines the independent and interactive effects of age and multiple sclerosis (MS) on health-related quality of life (HRQOL). MATERIALS AND METHODS: The sample included persons with MS (n = 207) and healthy controls (HCs; n = 99) divided into three age groups (young, middle-aged, and older adults) who completed a battery of questionnaires, including the 36-item Short-Form Health Survey (SF-36) as a measure of HRQOL. The SF-36 yielded scores for the Physical Component Summary (PCS) (i.e. physical HRQOL) and Mental Component Summary (MCS) (i.e. mental HRQOL). The data were analyzed using two-way MANOVA. RESULTS: There was no interaction between age and disease status on HRQOL, but there were significant main effects of age and disease status on HRQOL. HRQOL was significantly lower in participants with MS than HCs, regardless of age. Physical HRQOL was lower, whereas mental HRQOL was higher across age groups. CONCLUSION: The findings suggest that future research should develop behavioral and rehabilitation approaches that are applicable for improving HRQOL across the lifespan in persons with MS, particularly for physical HRQOL in older adults with MS.

Oxygen cost of walking and its relationship with body composition in multiple sclerosis.

BACKGROUND/OBJECTIVES: This cross-sectional study examined the relationship between the oxygen (O2) cost of walking and body composition metrics, while considering potential covariates such as disability status, step length, and cadence, in persons with multiple sclerosis (MS). SUBJECTS/METHODS: The sample included 63 persons with MS across a wide distribution of body mass index (BMI). O2 cost of walking was assessed using portable, indirect calorimetry, and percent body fat (%Fat), fat-free mass (FFM), bone mineral content, bone mineral density (BMD), and weight/FFM were determined from dual-energy x-ray absorptiometry. Other outcome measures included step length, cadence, physical activity, and disability status. RESULTS: The O2 cost of walking had small-to-moderate associations with BMI (rs = -31, p = 0.015), %Fat (rs = -0.26, p = 0.041), and BMD (rs = -0.31, p = 0.013). O2 cost of walking was significantly associated with these outcomes even after controlling for age, sex, disability status, and gait outcomes. The O2 cost of walking was further significantly associated with shorter step length (rs = -0.40, p = 0.001), slower cadence (rs = -0.38, p = 0.002), and higher disability status (rs = 0.44, p < 0.001), but not physical activity. Body composition metrics were not associated with gait parameters, physical activity or disability status in our sample of persons with mild-to-moderate MS. CONCLUSIONS: The results indicated that higher O2 cost of walking was associated with lower fat and worse bone health after taking factors such as disability status into consideration. Researchers may focus on interventions that change body composition, or perhaps gait profiles, as possible approaches for changing O2 cost of walking and its consequences such as disability status in persons with MS.

Diet, Physical Activity, and Stress Among Wheelchair Users With Multiple Sclerosis: Examining Individual and Co-Occurring Behavioral Risk Factors.

OBJECTIVE: This study examined individual and co-occurring behavioral risk factors (diet, exercise, and stress) in wheelchair users with multiple sclerosis (MS) and potential association with MS symptoms (ie, fatigue, depression, anxiety, pain, sleep, and health-related quality of life [HRQOL]). DESIGN: Survey. SETTING: General Community. PARTICIPANTS: One hundred twenty-three wheelchair users with MS completed this study (N=123). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Participants were mailed instructions for accessing online questionnaires (demographic and clinical characteristics, Godin Leisure-Time Exercise Questionnaire, Perceived Stress Scale, Automated Self-Administered 24-Hour Dietary Assessment Tool, and MS symptoms). RESULTS: Standard cut-points were used to categorize behavioral risk factors and then identify the extent and distribution of these behaviors both individually and co-occurring. We then analyzed the associations between behavioral risk factors and MS symptoms using bivariate correlation analyses and Mann-Whitney U tests. The mean age of participants was 60.6±10.0 years, 76% identified as women, 82% had a progressive disease course, and the mean MS duration was 23.0±9.7 years. Seven participants were classified as having 0 negative health behaviors, 41 participants had 1 negative health behavior, 49 participants had 2 negative health behaviors, and 26 participants had 3 negative health behaviors. The number of negative health behaviors was significantly correlated with HRQOL (physical, r=.30; psychological, r=.47), sleep (r=.25), depressive symptoms (r=.36), and anxiety (r=.43). Mann-Whitney U tests indicated greater fatigue, depression, and anxiety as well as lower sleep quality and HRQOL among participants who reported 2 or 3 behavioral risk factors compared with 0 or 1 behavioral risk factor. CONCLUSIONS: Future research should examine the design and implementation of multiple health behavior change interventions targeting co-occurring behavioral risk factors among wheelchair users with MS.

Physical Activity and Sedentary Behavior Timing in Fatigued and Nonfatigued Adults With Multiple Sclerosis.

OBJECTIVE: To examine device-measured physical activity levels and sedentary behavior participation during different times of the day (ie, morning, midday, and evening) in adults with multiple sclerosis (MS) who differed in fatigue status. DESIGN: Cross-sectional survey. SETTING: Remote survey study managed by a university-based research laboratory. PARTICIPANTS: A population-based sample of 1000 participants with MS were sent recruitment materials by the North American Research Committee on Multiple Sclerosis and 218 participants completed all relevant outcomes (N=218). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Participants (N=218) completed the Fatigue Severity Scale (FSS) as a measure of fatigue severity and were divided into subgroups of fatigued (FSS score ≥4) and nonfatigued (FSS score <4). Participants wore an ActiGraph GT3X+ on the nondominant hip for 7 days to measure physical activity (ie, light physical activity [LPA], moderate-to-vigorous physical activity [MVPA], steps) and sedentary behavior. RESULTS: Fatigued participants engaged in less MVPA (F[1216]=18.5, P<.001), fewer steps (F[1216]=27.8, P<.001), and more sedentary time (F[1216]=8.2, P=.005) than nonfatigued participants. Regardless of group, the highest levels of LPA (F[1.7355.7]=72.9, P<.001) and MVPA (F[1.8395.3]=23.0,P<.001) occurred in the morning and middle of the day, with the lowest levels in the evening. Regardless of group, the highest levels of sedentary behavior occurred in the evening, with similar levels in the morning and evening (F[1.6354.5]=84.3,P<.001). Regardless of group, participants had more steps in the middle of the day, followed by morning and then evening (F[1.8383.9]=84.7,P<.001). CONCLUSIONS: Our results suggest that physical activity timing should be considered in future development and delivery of behavior interventions that focus on increasing physical activity and reducing sedentary behavior among adults with MS who have fatigue.

Symptom clusters and quality of life in persons with multiple sclerosis across the lifespan.

PURPOSE: To describe symptom clusters based on severity of co-occurring symptoms among adults with multiple sclerosis (MS) by age groups and to further examine symptom clusters as a correlate of quality of life (QOL) by age groups. METHODS: This cross-sectional study enrolled persons with MS between 20 and 79 years of age who completed measures of fatigue, depression, anxiety, sleep quality, and QOL using the 36-Item Short Form Health Survey. Bivariate correlation and partial correlation analyses examined associations among symptoms, QOL, and MS characteristics. K-means cluster analyses determined symptom clusters among the full sample and pre-determined age groups (i.e., 20-39, 40-59, and 60-79). One-way ANOVAs examined differences in QOL among clusters for the overall sample and by age groups. RESULTS: Among the overall sample of 205 participants, symptoms were significantly correlated with QOL and three distinct clusters were identified and differentiated by the magnitude of symptom experience (i.e., mild, moderate, and severe). Results were consistent among young and middle-aged adults; however, among older adults two severe sleep problem clusters were identified that were distinguished by moderate versus severe fatigue, depression, and anxiety. ANOVAs among the overall sample indicated that the three symptom clusters varied significantly for both physical component scores, F(2, 202) = 12.03, p < .001, η2 = .10, and mental component scores, F(2, 202) = 137.92, p < .001, η2 = .58; severe symptom cluster was associated with worse QOL. Patterns in the age subgroup ANOVAs were consistent. CONCLUSIONS: Given the strong association between severity of symptom clusters and QOL, approaches for targeting co-occurring symptoms are critically needed.

Restless legs syndrome and health-related quality of life in adults with multiple sclerosis.

Restless legs syndrome (RLS) is a sleep disorder that may exacerbate many of the symptoms and consequences of multiple sclerosis (MS), and may have further implications for health-related quality of life (HRQOL). The present study examined the relationships among RLS, symptoms and HRQOL in people with MS. Participants with MS (n = 275) completed the Cambridge-Hopkins Restless Legs Syndrome Questionnaire, the International Restless Legs Syndrome Study Group Scale, the Multiple Sclerosis Impact Scale, the Pittsburgh Sleep Quality Index, the Fatigue Severity Scale, the Hospital Anxiety and Depression Scale and the Patient Determined Disease Steps. There were 74 (26.9%) persons with MS who had RLS (MS + RLS). The MS + RLS group reported worse physical and psychological HRQOL (p = 0.020 and p = 0.017, respectively) and greater perceived fatigue (p = 0.006) and anxiety symptoms (p = 0.042) than the MS-only group. Within the MS + RLS group, RLS severity was associated with physical (r = 0.43) and psychological (r = 0.46) HRQOL, sleep quality (r = 0.38), perceived fatigue (r = 0.28), depression (r = 0.38) and anxiety (r = 0.28). The relationships between RLS severity and the domains of HRQOL were attenuated when accounting for fatigue, depression and/or anxiety. Worse RLS severity was associated with reduced HRQOL, which was accounted for by fatigue, depression and anxiety.

Step-rate threshold for physical activity intensity in Parkinson's disease.

OBJECTIVES: To examine the relationship between step-rate and energy expenditure during treadmill walking in persons with PD and then further develop a step-rate cut-point for moderate-to-vigorous physical activity (MVPA) for persons with PD. MATERIALS AND METHODS: The sample consisted of 30 persons with mild-to-moderate PD and 30 controls matched by age and sex. Participants performed a 6-minute bout of over-ground walking at comfortable speed, and then completed three, 6-minute bouts of treadmill walking at 13.4 m/min slower, comfortable, and 13.4 m/min faster than comfortable speeds. The three treadmill speeds were based on the initial over-ground walking speed. The total number of steps per treadmill walking bout was recorded using a hand-tally counter, and energy expenditure was measured using a portable, indirect spirometry system. RESULTS: The results indicated a strong association between step-rate and energy expenditure for persons with PD (R2  = .92) and controls (R2  = .92). The analyses further indicated a steeper slope of the association for persons with PD compared with controls (t(58) = -1.87, P < .05), resulting in a lower step-rate threshold (t(58) = 2.19, P < .05) for persons with PD (~80 steps·per minutes) than controls (~93 steps·per minutes). CONCLUSION: Collectively, these results support the application of this disease-specific step-rate threshold for MVPA among persons with PD. This has important implications for physical activity promotion, prescription, and monitoring using accelerometers and pedometers for persons with PD to manage health and symptoms of PD.

Changes in Cognitive Performance With Age in Adults With Multiple Sclerosis.

BACKGROUND: Cognitive impairment is one of the most common consequences of multiple sclerosis (MS), yet there is a shortage of data regarding how cognition changes during the life span of individuals with MS. This information is of increasing importance given the growing proportion of older adults with MS. OBJECTIVE: To study possible changes in cognitive function in correlation with increasing age in individuals with MS. METHODS: Participants (N=129) were recruited and a priori allocated into one of three age groups (young, middle-aged, and older). All participants completed the Brief International Cognitive Assessment for Multiple Sclerosis (BICAMS) during a single laboratory testing session. The BICAMS measures cognitive processing speed as well as verbal and visuospatial learning and memory. RESULTS: A multivariate analysis of variance indicated that cognitive function significantly differed by age group, and these differences were not explained by amount of physical activity, years of education, years since diagnosis, or race. Older adults displayed significantly worse cognitive processing speed than young and middle-aged adults. The older and middle-aged adults also demonstrated significantly worse visuospatial learning and memory than the younger adults. Effect sizes indicated that cognitive processing speed and verbal learning and memory were more affected in late adulthood than early adulthood, whereas visuospatial learning and memory was affected similarly in early and late adulthood. CONCLUSIONS: Older adults with MS demonstrated significant impairments in cognitive function compared to young and middle-aged adults with MS. Future studies should determine the predictors of cognitive decline in this age cohort.

Cardiorespiratory Responses to Pool Floor Walking in People Poststroke.

OBJECTIVE: To compare cardiorespiratory responses between pool floor walking and overground walking (OW) in people poststroke. DESIGN: Cross-sectional study. SETTING: University-based therapeutic exercise facility. PARTICIPANTS: Participants (N=28) were comprised of 14 community-dwelling individuals poststroke (5.57±3.57y poststroke) and 14 age- and sex-matched healthy adults (mean age, 58.00±15.51y; male/female ratio, 9:5). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: A telemetric metabolic system was used to collect cardiorespiratory variables, including oxygen consumption (V˙o2), energy expenditure (EE), and expired volume per unit time (V˙e), during 6-minute walking sessions in chest-depth water and on land at a matched speed, determined by average of maximum walking speed in water. RESULTS: Individuals poststroke elicited no significant differences in cardiorespiratory responses between pool floor walking and OW. However, healthy controls showed significant increases in mean V˙o2 values by 94%, EE values by 109%, and V˙e values by 94% (all P<.05) during pool floor walking compared with OW. A 2×2 mixed model analysis of variance revealed a significant group × condition interaction in V˙o2, in which the control group increased V˙o2 from OW to pool floor walking, whereas the stroke group did not. CONCLUSIONS: Our results indicate that people poststroke, unlike healthy adults, do not increase EE while walking in water compared with on land. Unlike stationary walking on an aquatic treadmill, forward locomotion during pool floor walking at faster speeds may have increased drag force, which requires greater EE from healthy adults. Without demanding excessive EE, walking in water may offer a naturally supportive environment for gait training in the early stages of rehabilitation.

Post-exercise hypotensive responses following an acute bout of aquatic and overground treadmill walking in people post-stroke: a pilot study.

BACKGROUND: The purpose of this study is to investigate the effects of a single-bout of aquatic treadmill walking (ATW) and overground treadmill walking (OTW) on the magnitude and duration of post-exercise ambulatory blood pressure (BP) in people post-stroke. METHODS: Seven people post-stroke participated in a cross-sectional comparative study. BP was monitored for up to 9 hours after a 15-minute bout of ATW and OTW at approximately 70% of maximal oxygen consumption (VO2max), performed on separate days. Mean systolic and diastolic BP values were compared between both exercise conditions and a day without exercise (control). RESULTS: Three hours after OTW, mean SBP increased by 9% from pre-exercise baseline compared to a 3% decrease during the control day (P < 0.05). A similar trend was observed after the third hour of ATW (P = 0.06). However, ATW demonstrated a 3% overall decline in DBP after exercise compared to a 1% DBP increase of the control day (P < 0.05). Additionally, ATW showed a 6% reduction in mean systolic BP at the ninth hour post-exercise (P < 0.05) compared to baseline. CONCLUSION: Our results indicate people post-stroke can sustain sufficient walking intensities necessary to reduce BP following cardiovascular exercise. Also, these data suggest that ATW can elicit clinically meaningful reductions in DBP and night-time SBP. Thus, it is recommended for clinicians to consider ATW as a non-pharmaceutical means to regulate DBP and promote nighttime dipping of SBP in people post-stroke. However, caution is advised during the immediate hours after exercise, a period of possible BP inflation.

Do depressive and anxiety symptoms influence the construct validity of Multiple Sclerosis Walking Scale-12 scores?

PURPOSE/OBJECTIVE: Walking dysfunction, depression, and anxiety are prevalent, burdensome, and interrelated outcomes in persons with multiple sclerosis (MS). The 12-item Multiple Sclerosis Walking Scale (MSWS-12) is a common patient-reported outcome (PRO) of walking dysfunction in research and practice involving MS, but the construct validity of its scores might be influenced by symptoms of depression and anxiety. This study examined if symptoms of depression and anxiety influenced the construct validity of MSWS-12 scores. RESEARCH METHOD/DESIGN: The sample included 189 participants with MS who completed the MSWS-12, Hospital Anxiety and Depression Scale (HADS-Depression subscale [HADS-D] and HADS-Anxiety subscale [HADS-A]), 6-minute walk (6MW), and timed 25-foot walk (T25FW). We conducted bivariate correlation analysis to examine the associations between MSWS-12 scores and both the 6MW and T25FW, while controlling for HADS-D and HADS-A scores. RESULTS: MSWS-12 scores were significantly correlated with the 6MW (r = -.752), T25FW (r = .694), HADS-D (r = .405), and HADS-A (r = .235). The correlations between MSWS-12 and 6MW (pr = -.725) and T25FW (pr = .685) did not change when controlling for HADS-D and HADS-A scores. The correlations between MSWS-12 and 6MW (r = -.708 and r = -.726) and T25FW (r = .687 and r = .748) were strong in subsamples with elevated HADS-D and HADS-A scores. CONCLUSIONS/IMPLICATIONS: Our results strengthen the validity evidence for MSWS-12 scores as a PRO of walking dysfunction in MS, including among those with symptoms of depression and anxiety. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Updated Systematic Review and Quantitative Synthesis of Physical Activity Levels in Multiple Sclerosis.

OBJECTIVE: This article provided an updated quantitative synthesis of physical activity levels in persons with multiple sclerosis compared with controls and other clinical populations. DESIGN: A systematic search through PubMed, Scopus, and PsycINFO was conducted for articles published between August 2016 and July 2022. Articles that included a group comparison of at least one measurement of physical activity between adults with multiple sclerosis and controls or other clinical populations were included in the meta-analysis. RESULTS: Twenty-four studies met the inclusion criteria and yielded a total of 119 comparisons. There was a moderate difference in physical activity levels between persons with multiple sclerosis and controls (effect size = -0.56, P < 0.01), but no significant difference between persons with multiple sclerosis and other clinical populations (effect size = 0.01, P = 0.90). The pooled effect sizes comparing multiple sclerosis with controls ( Q104 = 457.9, P < 0.01) as well as with clinical populations ( Q13 = 108.4, P < 0.01) were heterogeneous. Moderating variables included sex, disability status, measurement method, outcome, intensity, and application of a multiple sclerosis-specific cut-point. CONCLUSIONS: Physical activity levels remain significantly lower in persons with multiple sclerosis compared with controls, but the magnitude of difference has become smaller over the past decade. There is a need for continued development of effective physical activity programs that can reach the greater community with multiple sclerosis.

Vascular dysfunction in multiple sclerosis: Scoping review of current evidence for informing future research directions.

BACKGROUND: The research involving vascular comorbidity in people with multiple sclerosis (MS) could be advanced through investigations applying measurements of vascular function such as pulse wave velocity or flow mediated dilation as mechanistic endpoints in the study of physical comorbidity management in MS across the lifespan. We conducted a scoping review of research on vascular function parameters and outcomes in MS and developed a research agenda for future inquiry. METHODS: We searched PubMed from inception through February 2023 for articles involving relevant central and peripheral vascular function data or correlates of vascular function (arterial stiffness, endothelial function, blood pressure parameters, etc.) in conjunction with relevant outcomes (walking function, cognition, etc.) in MS. Studies were limited to English-language and primary research articles. RESULTS: Our search and subsequent screening identified 10 relevant articles. Four papers focused on arterial stiffness and reported pulse wave velocity and arterial compliance in MS compared with controls. Two papers focused on endothelial function and reported flow-mediated dilation in MS compared with controls. There was evidence that arterial stiffness and endothelial function were associated with cognition and disease progression in MS, respectively. One paper reported that physical activity was associated with arterial stiffness in MS. There was one protocol paper examining the effect of a home-based exercise program on markers of subclinical atherosclerosis; however, the results are unpublished, and there was no literature beyond this surrounding the impact of lifestyle behavior (e.g., diet) or exercise interventions on vascular function. CONCLUSION: There is emerging evidence for vascular dysfunction in MS, and this is associated with cognition and disease progression; we know very little about approaches for managing vascular dysfunction in MS. To that end, we offer an agenda for research on measurements and outcomes of vascular function in relation to MS and disease attributes, along with proposed mechanisms and lifestyle changes that could aid in managing vascular dysfunction.

Effects of aerobic, resistance, and combined exercise training on health-related quality of life in multiple sclerosis: Systematic review and meta-analysis.

BACKGROUND: Multiple sclerosis (MS) is an immune-mediated, neurodegenerative disease of the central nervous system that manifests in symptoms that compromise health-related quality of life (HRQOL). HRQOL focuses on a person's overall, subjective evaluation of health status primarily in the physical and mental domains. Exercise training is a form of rehabilitation for managing MS-related outcomes that might influence HRQOL. Reviews on exercise training are available, but we are unaware of a recent comprehensive review and meta-analysis of exercise effects for improving physical and mental domains of HRQOL. This analysis provides an updated review and meta-analysis of randomized controlled trials (RCTs) examining interventions consisting of aerobic, resistance and combined exercise training for improving HRQOL in persons with MS. This systematic review 1) assessed the overall strength of evidence for exercise interventions on HRQOL, 2) evaluated the relative effect of exercise interventions on physical and mental domains of HRQOL, and 3) determined moderators of exercise intervention effects on HRQOL. METHODS: Seven databases were searched for RCTs evaluating physical and/or mental domains of HRQOL with adults diagnosed with MS and undergoing an intervention of aerobic, resistance or combined exercise training compared with a non-exercise comparator. Data extraction included participant and intervention characteristics, and pre- and post-intervention HRQOL outcome data. Effect sizes (ESs) were calculated as standardized mean differences (SMDs) and a multilevel random-effects model was used to generate an aggregated SMD that compared exercise with non-exercise control conditions. RESULTS: Twelve RCTs met the inclusion criteria and yielded 23 ESs to be analyzed. Participants (N = 593; 308 intervention vs. 285 control conditions) had a mean (±standard deviation) age of 42.4 (6.5) years and 80% (18.3%) were female. Results generated a medium effect of exercise for improving overall HRQOL (ES=0.64, p = 0.0001) with high heterogeneity (Q11=58.8, I2=86.7%). Exercise training yielded a large effect on the physical domain (k = 12, ES=0.82, p<0.0009) and a medium effect on the mental domain (k = 11, ES=0.41, p<0.0001). Moderator analyses identified exercise modality, supervision level, intervention delivery and length, HRQOL tool, and number of participants with relapsing-remitting MS as significant influences of ES for HRQOL. CONCLUSIONS: Exercise training is clinically effective for improving overall HRQOL in MS and produces greater improvements in the physical domain of HRQOL than the mental domain. The moderator analysis suggests that supervised, aerobic, and group-delivered exercise training of ≥3 months yields the most influence on HRQOL. Such results may have major implications for MS treatment and care.

Physical function across the lifespan in adults with multiple sclerosis: An application of the Short Physical Performance Battery.

BACKGROUND: Multiple sclerosis (MS) typically has its onset in early and middle adulthood, but the population is steadily becoming more dominated by older adults. One of the primary consequences of both MS and aging involves declines of lower extremity physical function and mobility. This cross-sectional study compared physical function status based on Short Physical Performance Battery (SPPB) summary and component scores between persons with MS and healthy controls across 6 age groups. We further examined associations between SPPB summary scores and component scores as well as associations between summary scores and measures of physical and cognitive function for identifying the strongest correlates of SPPB summary scores. METHODS: The study involved secondary analysis of cross-sectional data from multiple studies. Ambulatory adults with MS who were relapse-free for the last 30 days were recruited, and controls were recruited based on similar criteria to adults with MS except without the diagnosis of MS or relapses. The sample of 345 persons with MS and 174 controls completed questionnaires regarding demographic and clinical information and underwent assessments of physical and cognitive function including the SPPB, 6-Minute Walk, Timed 25-Foot Walk, Symbol Digit Modalities Test, California Verbal Learning Test-Second Edition, and Brief Visuospatial Memory Test-Revised. RESULTS: The two-way ANOVA indicated a main effect of MS status (F(5,500)=34.74, p<.01, η2=0.065), a main effect of age (F(1,500)=3.88, p<.01, η2=0.037), and no MS status by age interaction (F(5,500)=1.20, p=.31, η2=0.012) on SPPB scores. The bivariate correlation analysis indicated that summary SPPB scores were associated with component SPPB scores in the overall samples of persons with MS (rs=0.71 to 0.83) and controls (rs=0.42 to 0.91) as well as within most age groups of MS (rs=0.63 to 0.91) and controls (rs=0.34 to 1.00). The associations between SPPB scores and physical function outcomes were larger in the sample of persons with MS (rs=-0.72 to 0.76) than controls (rs=-0.47 to 0.48). SPPB scores were further significantly associated with scores on cognitive outcomes in persons with MS (rs=0.31 to 0.43), whereas these associations were weaker in controls (rs=0.09 to 0.32). Overall, the associations between SPPB scores and physical function outcomes were stronger than the associations between SPPB scores and cognitive function outcomes. CONCLUSION: Overall, MS status and aging have additive effects on physical function, and the summary SPPB score may be driven by a specific component within each age group. SPPB scores may be driven more by mobility rather than cognition, and are consistent with cognitive-motor coupling in MS. The novelty of this study provides evidence of worsening physical function based on the application of the SPPB and its scores across the lifespan in persons with MS and controls, and this has important implications particularly given the increasing prevalence of older adults with MS.

Systematic review and meta-analysis of sedentary behavior in persons with multiple sclerosis.

BACKGROUND: Persons with multiple sclerosis (MS) engage in less physical activity than the general population, and the disease manifestations and comorbidity conditions might further predispose them toward sedentary behavior (SB) among this population. We performed a systematic review with meta-analysis of studies that compared SB in persons with MS and non-MS controls, and examined factors that may moderate the difference in SB between the two groups. METHODS: We conducted a systematic search using PubMed, PsycINFO, Scopus, and CINAHL from inception up to August 2022, and identified studies that involved group comparison of SB outcomes between MS and non-MS controls. Effect sizes were calculated as standardized mean differences (SMDs) using Hedge's g. We generated a multilevel random-effects model for estimating an overall effect, and performed moderator analyses. Methodological quality was assessed using the Appraisal Tool for Cross-Sectional Studies (AXIS tool). RESULTS: Eleven studies were included (1403 MS vs. 449 controls) and yielded 17 effects for meta-analysis. Results indicated an overall small, but significant effect (SMD [95% CI] = 0.27 [0.02, 0.53], p = 0.03) with significant heterogeneity (Q16 = 72.2, p < 0.01; I2total = 75.8%). There were larger effects when the MS sample had a higher proportion of females, or when SB was reported as percent sedentary time per day compared with other SB outcomes (p = 0.03 and 0.05, respectively). The included studies achieved fairly good quality (91.4%) using the AXIS tool. CONCLUSIONS: The cumulative evidence supports that persons with MS engage in more SB than non-MS controls. Our findings may support the design of targeted behavioral change interventions for reducing SB and improving health and function in the MS population.

Free-Living Peak Cadence in Multiple Sclerosis: A New Measure of Real-World Walking?

BACKGROUND: Physical function and walking performance have become important outcomes in clinical trials and rehabilitation involving persons with multiple sclerosis (MS). However, assessments conducted in controlled settings may not reflect real-world capacity and movement in a natural environment. Peak cadence via accelerometry might represent a novel measure of walking intensity and prolonged natural effort under free-living conditions. OBJECTIVE: We compared peak 30-minute cadence, peak 1-minute cadence, and time spent in incremental cadence bands between persons with MS and healthy controls, and examined the associations between peak cadence and laboratory-assessed physical function and walking performance. METHODS: Participants (147 MS and 54 healthy controls) completed questionnaires on disability status and self-reported physical activity, underwent the Short Physical Performance Battery, Timed 25-Foot Walk, Timed Up and Go, and 6-Minute Walk, and wore an accelerometer for 7 days. We performed independent samples t-tests and Spearman bivariate and partial correlations adjusting for daily steps. RESULTS: The MS sample demonstrated lower physical function and walking performance scores, daily steps, and peak cadence (P < .001), and spent less time in purposeful steps and slow-to-brisk walking (40-119 steps/minutes), but accumulated more incidental movement (1-19 steps/minutes) than healthy controls. The associations between peak cadence and performance outcomes were strong in MS (|rs| = 0.59-0.68) and remained significant after controlling for daily steps (|prs| = 0.22-0.44), P-values < .01. Peak cadence was inversely correlated with age and disability, regardless of daily steps (P < .01). CONCLUSIONS: Our findings provide preliminary evidence for the potential use of peak cadence with step-based metrics for comprehensively evaluating free-living walking performance in MS.

Validity of the 30-Second Sit-to-Stand test as a measure of lower extremity function in persons with multiple sclerosis: Preliminary evidence.

BACKGROUND: The 30-Second Sit-To-Stand (30SSTS) is a quick, inexpensive, safe, and widely used clinical measure of lower extremity function. To date, there is limited evidence regarding the use of 30SSTS in multiple sclerosis (MS). The purpose of this study was to examine the construct validity of the 30SSTS test in persons with MS compared with non-MS healthy controls. METHODS: Twenty ambulatory persons with MS and twenty age- and sex-matched healthy controls completed the 30SSTS, Timed 25-Foot Walk (T25FW), Timed Up and Go (TUG), Six-Minute Walk (6MW), and Godin Leisure-Time Exercise Questionnaire (GLTEQ). Persons with MS also completed the Patient Determined Disease Steps (PDDS) and 12-item MS Walking Scale (MSWS-12). RESULTS: Persons with MS had significantly worse performance on the TUG (mean difference [95% confidence interval] = 1.4 [0.5, 2.3] sec) and 6MW (-259.2 [-450.8, -67.6] ft), but not on the 30SSTS (-1.6 [-1.5, 4.6] reps) and T25FW (-0.59 [-0.1, 1.2] ft/sec) compared with controls. There were significant moderate-to-strong correlations between the 30SSTS with T25FW, TUG, and 6MW scores in persons with MS (r = 0.48, -0.65 and 0.61, respectively), whereas the 30SSTS was only significantly associated with 6MW scores (r = 0.43) in controls. The 30SSTS was negatively associated with MS-related walking disability assessed by the PDDS and MSWS-12 (rs = -0.52 and -0.64, respectively), but was not significantly associated with the GLTEQ in MS and controls (r = 0.30 and 0.17, respectively). CONCLUSION: This study provides initial support for the construct validity of the 30SSTS as a measure of lower extremity function in persons with MS. Our findings warrant the inclusion of the 30SSTS as a feasible and valid measure of physical function in clinical research and practice involving persons with MS.

No association between body composition and walking outcomes in multiple sclerosis.

BACKGROUND: One 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. METHODS: Ambulatory 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. RESULTS: Body 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. CONCLUSION: Our 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.