Experimental protocol of a randomized controlled clinical trial investigating exercise, subclinical atherosclerosis, and walking mobility in persons with multiple sclerosis

Inverse association between arterial stiffness and perceived fatigue independent of disability status and BMI in multiple sclerosis

INTRODUCTION

Multiple sclerosis (MS) is an immune-mediated, neurodegenerative disease of the central nervous system. Fatigue represents one of the most prevalent and limiting symptoms of MS, and is associated with vascular dysfunction, notably increased arterial stiffness.

OBJECTIVE

This study examined the relationship between arterial stiffness and perceived fatigue in persons with MS.

METHODS

The sample of 52 persons with MS (71.2% Female; Age: 46.7 ± 12.3 yrs.) completed arterial stiffness and fatigue assessments as baseline for an exercise training intervention. Applanation tonometry measured arterial stiffness, pulsatility and waveform characteristics, and yielded the following outcomes: carotid-femoral pulse wave velocity (cfPWV), carotid pulse-pressure (cPP), and aortic augmentation pressure (AP). Perceived fatigue was measured using the Fatigue Severity Scale (FSS).

RESULTS

The mean (SD) scores for cfPWV, cPP, and AP were 7.0 ± 1.8 m/s, 35.7 ± 8.8 mmHg, 8.2 ± 6.2 mmHg, respectively. The mean (SD) FSS score was 4.6 ± 1.4 and indicated elevated fatigue. There were statistically significant (p < .05) inverse correlations between cfPWV (r = -.32), cPP (r = -.37) and AP (r = -.32) with FSS scores, and the correlations remained significant even after controlling for disability, body mass index, age, and sex.

CONCLUSION

Our results indicate a consistent pattern of inverse relationships between arterial stiffness, pulsatility, and waveforms with fatigue independent of disability, body mass index, age, and sex in MS. This could be explained by lower sympathetic activation linking higher arterial stiffness, pulsatility and augmentation pressure with lower fatigue in persons with MS.

Home-based exercise improves subclinical atherosclerosis marker in multiple sclerosis

PURPOSE

Using a 12-week, randomized controlled trial coupled with social cognitive theory behavioral coaching, we aimed to assess the effect of a home-based aerobic training intervention versus an attention-control on aerobic fitness, subclinical atherosclerosis, and mobility in persons with MS.

METHODS

Persons with MS with an expanded disability status scale score between 0 and 4 were randomized to a 12-week aerobic exercise (EX) (n = 26; 19 females; 49 yrs; 28.8 kg/m2) or attention-control (CON) condition (stretching; n = 22; 16 females; 44 yrs; 29.2 kg/m2). Aerobic capacity was assessed via a graded cycle ergometry test with indirect calorimetry. The co-primary measures of subclinical atherosclerosis assessed included carotid intima media thickness, a test of vasodilatory reactivity, and arterial stiffness. Mobility was assessed via a timed 25-foot walk test (T25FW) and a 6 min walk test. The EX group engaged in cycle ergometry 3d/wk with gradual increases in the intensity and duration of the exercise sessions. CON participated in standardized stretching designed to provide the same contact time as EX 3d/wk. Behavioral coaching took place via weekly phone/video chats to track adherence.

RESULTS

Aerobic capacity, vasodilatory reactivity, and T25FW speed increased only in the EX group, 7%, 16%, and 13% (p<0.05), respectively; whereas the CON group did not change.

CONCLUSION

The EX group had modest, yet significant, increases in aerobic capacity over the 12-week period, coupled with improvements in T25FW speed and vasodilatory reactivity. A home-based exercise intervention can improve outcomes of a subclinical marker of atherosclerosis, which provides a basis for examining these outcomes in persons prescreened for CVD-related comorbidities and/or mobility issues.

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.

Lessons learned from clinical trials of exercise and physical activity in people with MS - guidance for improving the quality of future research

The body of research on exercise and physical activity among persons with multiple sclerosis(MS) has expanded rapidly in quantity, but not necessarily quality, over the past 20+ years. There is evidence for beneficial effects of exercise and physical activity on immune cells and neurotrophic factors, brain structure and function, walking and cognitive performance, fatigue, depression, and pain, and quality of life among persons with MS. Nevertheless, there is heterogeneity in the outcomes of exercise and physical activity, and a recognition of substantial challenges for improving the effectiveness of those behaviors in MS. To move the field forward, members of the National MS Society physical wellness research working-group pooled collective experiences for identifying challenges, logistic complexities, and opportunities for researchers in designing and conducting interventions of exercise and physical activity among persons with MS. We examined the scope of our experiences and identified collective "lessons learned" regarding the behaviors themselves; study design features and stage of research; study setting, safety, and sample selection; and implementation of randomized controlled trials(RCTs) and treatment fidelity. This paper provides a resource that can inform researchers, particularly new investigators or established investigators transitioning into MS, on conducting high-quality RCTs on exercise and physical activity in MS.

Systematic review of participant characteristics in theory-based behavior change interventions for physical activity in multiple sclerosis: are we missing those with the greatest potential for lifelong benefits?

PURPOSE

This study examined participant characteristics, particularly disease duration, in theory-based physical activity behavior change trials in multiple sclerosis (MS) and summarized theoretical frameworks and changes in physical activity outcomes.

MATERIALS AND METHODS

PubMed, CINAHL, Embase, and Scopus were searched to identify potential trials. One reviewer screened titles and abstracts, and two reviewers then independently screened full-text articles based on predetermined eligibility criteria. Data were extracted by one reviewer and checked by a second reviewer.

RESULTS

Among 33 trials reviewed, only one trial reported a mean disease duration of less than five years (i.e., 4.5 years) for the sample. The remaining trials included samples with a mean disease duration of 6.7 years or longer. The most common theories used were Social Cognitive Theory, Trans-theoretical Model, and Motivational Interviewing. The effects on physical activity were heterogeneous; device-measured outcomes increased in 41.4% of studies, self-reported outcomes improved in 72.4%. Adherence (≥80%) was reported in 34.5% of studies.

CONCLUSIONS

There is little focus on persons with MS in the early disease course in physical activity behavior change interventions. Future research should include comprehensive theoretical approaches for more homogeneous effects across outcome measures when targeting those in the early stage and all MS populations.IMPLICATIONS FOR REHABILITATIONTheory-based physical activity behavior change interventions have not included persons with multiple sclerosis (MS) in the early disease course (<5 years since diagnosis).Disease duration has not been a criterion used to include or exclude participants in the reviewed theory-based behavior change interventions for physical activity in people with MS.The theory-based behavior change interventions in this review positively affected short-term physical activity levels in people with MS.

Behavior Change Techniques in Physical Activity Interventions for Multiple Sclerosis

OBJECTIVE

To identify and summarize the behavior change techniques (BCTs) included in behavior change interventions for promoting physical activity in persons with multiple sclerosis (MS).

DATA SOURCES

PubMed, PsycINFO, Cumulative Index to Nursing and Allied Health Complete, Scopus, and Embase were initially searched in November 2019, and data extraction began in June 2020.

STUDY SELECTION

The inclusion criteria for studies were: adults older than 18 years with diagnosed MS, English language, clinical trial designs (ie, pre-post or randomized controlled trials), group or individual interventions, and home or community-based settings wherein physical activity was defined as a primary or secondary outcome. Exclusion criteria for studies included protocol manuscripts pending results, case studies, studies focused on populations with multiple chronic diseases, and interventions targeting multiple behaviors. Two researchers completed screening for study selection, and a third researcher served as a referee. Of the initially identified 8681 studies, 54 studies met selection criteria.

DATA EXTRACTION

Data extraction was completed by 3 researchers. Each article was coded by 2 of the 3 researchers, and a fourth researcher resolved discrepancies. Data extracted from each paper included study title, authors, country, year, sample size, study design, intervention details, physical activity outcomes, and BCTs.

DATA SYNTHESIS

Thirty-eight unique behavior change interventions were identified, and 53 of the 93 possible BCTs were included across the studies. The mean number of BCTs per study was 15, and studies and effect sizes across studies ranged from 0.04-1.49.

CONCLUSIONS

This review provides a comprehensive overview of BCTs as the active ingredients in behavior change interventions targeting physical activity in MS. Results from this study provide a compendium for future intervention development for increasing physical activity and improving overall health in MS.

Physical activity and peak oxygen consumption are associated with walking in multiple sclerosis

INTRODUCTION

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system with a prevalence of nearly 1 million adults in the United States. MS results in declines in physical activity and peak oxygen consumption that might be independently associated with declines in walking performance. Therefore our purpose was to evaluate the association between physical activity and peak oxygen consumption with walking performance in individuals with MS.

METHODS

Fifty individuals with MS between the ages of 18-70 yrs. (Female: 38; 46  ±  12 yrs.; BMI: 28.5  ±  6.4; EDSS: 3.3 [IQR: 2.5-4]) performed a maximal incremental cycle test to assess peak oxygen consumption (VO_2peak), and wore an accelerometer for one week to measure moderate-to-vigorous physical activity (MVPA). Subjects further completed a timed 25-foot walk test (T25FW) and 6-minute walk (6MW) to measure walking performance.

RESULTS

MVPA and VO₂peak were correlated with 6MW and T25FW (p < 0.05). When combined in multivariate regression analyses, VO_2peak and MVPA were both significant contributors of T25FW speed and 6MW, but after controlling for sex and age, MVPA was the only significant contributor (β = 0.32 and β = 0.44, respectively).

CONCLUSION

Both higher MVPA and VO_2peak were associated with better walking performance and in a combined model physical activity, but not peak oxygen consumption, remained an independent contributor to walking performance in individuals with MS. These results suggest that improving MVPA is a potential target for interventions to improve walking performance in persons with MS.