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.

Preferred Behavior Change Techniques for Physical Activity Interventions among Persons Newly Diagnosed with Multiple Sclerosis: A Qualitative Study.

There is increasing interest by researchers and clinicians in behavior change interventions for promoting physical activity in persons newly diagnosed with MS. Ideally, such interventions require the delivery of behavior change techniques (BCTs) based on theory and the selection of BCTs might further require tailoring for this MS subpopulation. The current study examined BCTs preferred by persons newly diagnosed with MS for informing the design and delivery of physical activity behavior change interventions in early-stages of MS. We recruited and interviewed 20 persons newly diagnosed with MS (i.e., disease duration ≤ 2 years). The interviews were conducted online via video conferencing platform and followed a semi-structured script. During the interviews, participants provided opinions regarding an ideal physical activity behavior change program, and the opinions of participants were mapped with the Intervention Functions of the Behavior Change Wheel, BCTs, and BCT groups. Ten frequently mentioned BCTs were identified as preferred strategies for a physical activity behavior change intervention among persons newly diagnosed with MS. These BCTs focused on providing social support, skills and strategies for physical activity performance and regulation, and knowledge on benefits of physical activity in MS. This research provides a refined list of BCTs that can be included when designing tailored physical activity behavior change interventions for persons newly diagnosed 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.

Physical Activity and Quality of Life in Persons Newly Diagnosed With Multiple Sclerosis: A Cross-sectional Study.

OBJECTIVE: To examine the association between physical activity (PA) and quality of life (QOL) in persons newly diagnosed with multiple sclerosis (MS) who have been under-represented in MS research. DESIGN: Cross-sectional study with secondary data analysis. SETTING: General community. PARTICIPANTS: The study included 152 persons newly diagnosed with MS (ie, diagnosed with MS within the past 2 years) aged 18 and older (N=152). MAIN OUTCOME MEASURES: Participants completed the Godin Leisure-Time Exercise Questionnaire to measure PA. QOL, disability status, fatigue, mood, and comorbidity were assessed using the 12-Item Short Form Survey (SF-12), Patient Determined Disease Steps, Hamburg Quality of Life Questionnaire Multiple Sclerosis, and comorbidity questionnaire. RESULTS: The bivariate correlations indicated that PA was significantly and positively associated with the physical component of QOL (ie, SF-12 PCS) (r=0.46). The stepwise multiple linear regression analysis indicated PA as associated with SF-12 PCS (ß=0.43, R2=0.17) when solely included in the model. After controlling for fatigue, mood, disability status, and comorbidity as covariates (R2=0.63), the association between PA and SF-12 PCS was still statistically significant, but attenuated in magnitude (ß=0.11). CONCLUSIONS: This study observed that PA was significantly associated with the physical component of QOL in persons newly diagnosed with MS, even after controlling for covariates. The findings underscore the importance of developing behavior change interventions targeting PA while addressing the roles of fatigue and disability status for enhancing the physical component of QOL of this MS subpopulation.

Long-Term Measurements of Human Inflammatory Cytokines Reveal Complex Baseline Variations between Individuals.

Comprehensive characterization of the healthy human proteome baseline is essential for personalized medicine. Baseline data are necessary to understand the variation between individuals, as well as longitudinal variation within individuals. Many important protein biomarkers, such as cytokines, exist at extremely low or undetectable levels in the healthy state. This paper describes results from a 14-week study of healthy human subjects using ultrasensitive single-molecule array (Simoa) assays to measure both intra and intersubject variation of 15 cytokines. The results show a wide variation in the ranges of some cytokines between individuals and demonstrate that individual baseline values will be essential for predicting disease presence and progression. Although all of the studied cytokines demonstrated high temporal stability (or low intrasubject variation) over the entire study period, there were two distinct groups of cytokines that demonstrated either high (IL-8, IFN-γ, IL-2, IL-6, and IL-1ß) or low (IL-15, TNF-α, IL-12 p70, IL-17A, GM-CSF, IL-12 p40, IL-10, IL-7, IL-1α, and IL-5) subject-to-subject variation. This work demonstrates that ultrasensitive assays are essential for characterizing human cytokines in healthy subjects. The results show that some cytokines vary by more than two orders of magnitude between individuals, making it an imperative to obtain individual baseline measurements if they are to play a role in health and disease diagnosis.

Using Antigen-antibody Binding Kinetic Parameters to Understand Single-Molecule Array Immunoassay Performance.

This paper provides insights into the performance of single-molecule array (Simoa) immunoassays by examining the effects of various capture and detector antibody-antigen binding kinetic parameters. Simoa is similar to other immunoassays in that the overall Simoa performance is heavily dependent on the choice of antibodies; however, little is known about how the different properties of the antibodies result in the wide variations in assay performance. Here, we focus on antibody-antigen binding kinetics and demonstrate how the association (kon) and dissociation (koff) rate constants of the capture and detection antibodies affect Simoa performance. We compared six different antibodies with over a four-log range of equilibrium dissociation constants (KD) and found that Simoa assay performance had an inverse relationship to the koff value of the detection antibody. The Simoa fluorescent signals were highest when the koff of the detection antibody was less than 10-5 s-1. The capture antibody koff did not have as significant an effect, but a koff of less than 10-3 s-1 was preferred. We also found that the kon values of the capture and detection antibodies were not important factors for Simoa performance. Therefore, the assay optimization process could be accelerated by choosing detection antibodies with the slowest koff values.

Pancreas volume and fat fraction in children with Type 1 diabetes.

AIMS: People with Type 1 diabetes have smaller pancreases than healthy individuals. Several diseases causing pancreatic atrophy are associated with pancreatic steatosis, but pancreatic fat in Type 1 diabetes has not been measured. This cross-sectional study aimed to compare pancreas size and fat fraction in children with Type 1 diabetes and controls. METHODS: The volume and fat fraction of the pancreases of 22 children with Type 1 diabetes and 29 controls were determined using magnetic resonance imaging. RESULTS: Pancreas volume was 27% smaller in children with diabetes (median 34.9 cm(3) ) than in controls (47.8 cm(3) ; P < 0.001). Pancreas volume correlated positively with age in controls (P = 0.033), but not in children with diabetes (P = 0.649). Pancreas volume did not correlate with diabetes duration, but it did correlate positively with units of insulin/kg body weight/day (P = 0.048). A linear model of pancreas volume as influenced by age, body surface area and insulin units/kg body weight/day found that insulin dosage correlated with pancreas volume after controlling for both age and body surface area (P = 0.009). Pancreatic fat fraction was not significantly different between the two groups (1.34% vs. 1.57%; P = 0.891). CONCLUSIONS: Our findings do not indicate that pancreatic atrophy in Type 1 diabetes is associated with an increased pancreatic fat fraction, unlike some other diseases featuring reduced pancreatic volume. We speculate that our results may support the hypotheses that much of pancreatic atrophy in Type 1 diabetes occurs before the clinical onset of the disease and that exogenous insulin administration decelerates pancreatic atrophy after diabetes onset.

Ultrasensitive Detection of Ricin Toxin in Multiple Sample Matrixes Using Single-Domain Antibodies.

Ricin is an extremely potent ribosomal inactivating protein listed as a Category B select agent. Although ricin intoxication is not transmittable from person to person, even a single ricin molecule can lead to cell necrosis because it inactivates 1500 ribosomes/min. Since there is currently no vaccine or therapeutic treatment for ricin intoxication, ultrasensitive analytical assays capable of detecting ricin in a variety of matrixes are urgently needed to limit exposure to individuals as well as communities. In this paper, we present the development and application of a single-molecule array (Simoa) for the detection of ricin toxin in human urine and serum. Single-domain antibodies (sdAbs), among the smallest engineered binding fragments, were chemically coupled to the surface of paramagnetic beads for the sensitive detection of ricin toxin. The Simoa was able to detect ricin at levels of 10 fg/mL, 100 fg/mL, and 1 pg/mL in buffer, urine and serum, respectively, in a fraction of the assay time need using immuno-polymerase chain reaction (IPCR). Using a fully automated state-of-the-art platform, the Simoa HD-1 analyzer, the assay time was reduced to 64 min.

Feasibility of a theory-based physical activity intervention for persons newly diagnosed with multiple sclerosis.

BACKGROUND: Physical activity (PA) is beneficial for rehabilitation and symptom management in multiple sclerosis (MS), yet persons newly diagnosed with MS are insufficiently active and have not been the focus of PA research. This is important as early initiation of lifestyle PA, alongside other disease modifying therapies, might maximize the lasting benefits of this behavior on health outcomes and health-related quality of life (HRQOL) in MS. PURPOSE: This single group, pre-post study examined the feasibility and initial efficacy of a 12-week remotely delivered COM-B-based behavior change intervention targeting lifestyle PA in persons newly diagnosed with MS. METHODS: Persons newly diagnosed with MS (diagnosis of 2 years or less) were recruited for the study. The intervention was designed based on COM-B and formative research, and included a program manual, newsletters, video coaching calls, pedometer, logbook, and calendar. Feasibility was assessed in four domains: process (e.g., recruitment, retention), resource (e.g., time and costs), management (e.g., data management), and scientific evidence (e.g., safety, treatment effects). RESULTS: Thirty-two persons newly diagnosed with MS underwent screening, 17 were eligible, and 14 started the intervention. Twelve participants completed the study (86 % retention rate). All participants in the intervention engaged in 100 % of video coaching calls and participants provided 73 % of online step count entries. Eighty-three percent of participants fully complied with reviewing the newsletters. No relapses were reported during the intervention. There were moderate-to-large increases in PA outcomes, as measured by the Godin Leisure-Time Exercise Questionnaire, International Physical Activity Questionnaire, and accelerometry (light PA) (d ≥ 0.5). There were no significant changes in other accelerometry outcomes, including step counts and moderate-to-vigorous PA (d = 0.2). There were large, positive effects of the intervention on physical and mental health-related quality of life with (d ≥ 1), but the change in fatigue severity was small and not statistically significant among the study participants (d = 0.3). CONCLUSIONS: This study provides evidence for feasibility and initial efficacy of a COM-B-based PA intervention for persons newly diagnosed with MS. The results indicate that this intervention was feasible, safe, acceptable, and promising for promoting lifestyle PA in persons newly diagnosed with MS.

Walking and physical performance in black and white adults with multiple sclerosis controlling for social determinants of health.

BACKGROUND: There is evidence for reduced walking and physical performance in persons with multiple sclerosis (MS) compared with healthy controls (HCs). There is further evidence suggesting increased overall mobility disability in Black persons with MS compared with White counterparts, yet little is known about the interplay of social determinants of health (SDOH) when considering differences in walking and physical performance. PURPOSE: This cross-sectional, comparative study examined differences in walking and physical performance in Black and White persons with MS and HCs (MS Status), statistically controlling for SDOH. METHODS: The study sample consisted of 208 persons with MS (141 White participants and 67 Black participants) and 95 HCs (59 White participants and 36 Black participants). Walking and physical function were measured using timed 25-foot walk (T25FW), six-minute walk (6MW), timed-up-and-go (TUG), and short physical performance battery (SPPB). We examined the differences in the walking and physical functions as a function of MS Status (MS vs. HCs) and Race (Black vs. White) using Multivariate Analysis of Covariance, controlling for age, sex, marital status and SDOH (i.e., education, employment, income). RESULTS: There were no significant interactions between MS Status and Race on the outcomes, and the main effects of MS Status and Race remained statistically significant, controlling for SDOH and covariates. The main effects indicated significant lower T25FW (F = 34.6, p < .001, È p2 = 0.11), 6MW (F = 58.5, p < .001, È p2 = 0.18), TUG (F = 22.1, p < .001, È p2 = 0.08), and SPPB (F = 25.2, p < .001, È p2 = 0.09) performance for MS than HCs, and lower T25FW (F = 15.5, p < .001, È p2 = 0.05), 6MW (F = 11.6, p < .001, È p2 = 0.04), and TUG (F = 4.1, p < .05, È p2 = 0.02) performance in Black than White samples. CONCLUSIONS: We conclude that MS Status and Race independently influence walking and physical performance even after accounting for SDOH, and Black persons with MS have compromised walking and physical performance, perhaps necessitating focal rehabilitation.

Physical Activity in Individuals Newly Diagnosed With Multiple Sclerosis Through the Lens of the COM-B Model.

BACKGROUND: Physical activity (PA) is a promising intervention for disease modification and symptom management in multiple sclerosis (MS); however, there is a lack of research focusing on PA behavior change interventions for persons newly diagnosed with MS. Such PA behavior change interventions should be developed based on a strong empirical foundation of understanding the behavior and its determinants (ie, what to target for changes to occur). To that end, this qualitative study examined factors explaining PA in persons newly diagnosed with MS and identified potential targets for future behavior change intervention development based on the Capability-Opportunity-Motivation-Behavior (COM-B) model. METHODS: Twenty individuals diagnosed with MS within the past 2 years underwent one-on-one semistructured interviews using questions developed based on the COM-B model. Data were analyzed using reflective thematic analysis, and the identified themes were then mapped with the COM-B model. RESULTS: Factors explaining PA in the study sample were identified across the COM-B components. The typical factors include knowledge and skills to sufficiently engage in PA with appropriate approaches, ability to adapt and navigate through new environmental and social difficulties after diagnosis, and motivation resulting from a combination of factors, such as outcome expectation, belief of capabilities, role/identity, reinforcement, and emotions. CONCLUSIONS: The COM-B model was applied successfully in this study to understand PA behavior and identify potential targets for behavior change in individuals newly diagnosed with MS. Future behavior change interventions should consider addressing these factors to generate effective PA behavior change in this population.

[Corneal epithelial biomechanics: Resistance to stress and role in healing and remodeling]. / Biomécanique de l'épithélium cornéen : résistance au stress et implications dans la cicatrisation et le remodelage.

The corneal epithelium is one of the first tissue barriers of the eye against the environment. In recent years, many studies provided better knowledge of its healing, its behavior and its essential role in the optical system of the eye. At the crossroads of basic science and clinical medicine, the study of the mechanical stresses applied to the cornea makes it possible to learn the behavior of epithelial cells and better understand ocular surface disease. We describe herein the current knowledge about the adhesion systems of the corneal epithelium and their resistance to mechanical stress. We will also describe the involvement of these mechanisms in corneal healing and their role in epithelial dynamics. Adhesion molecules of the epithelial cells, especially hemidesmosomes, allow the tissue cohesion required to maintain the integrity of the corneal epithelium against the shearing forces of the eyelids as well as external forces. Their regeneration after a corneal injury is mandatory for the restoration of a healthy epithelium. Mechanotransduction plays a significant role in regulating epithelial cell behavior, and the study of the epithelium's response to mechanical forces helps to better understand the evolution of epithelial profiles after refractive surgery. A better understanding of corneal epithelial biomechanics could also help improve future therapies, particularly in the field of tissue engineering.

Physical activity behavior in persons newly diagnosed with multiple sclerosis: Applying the Capability - Opportunity - Motivation - Behavior (COM-B) model.

BACKGROUND: Physical activity (PA) research in multiple sclerosis (MS) typically has not focused on persons newly diagnosed with the disease. This is noteworthy as PA might be most amenable for change in the early stages of MS and further yield long-term benefits over the disease course. PURPOSE: This study examined correlates of PA based on the Capability-Opportunity-Motivation-Behavior (COM-B) model in persons newly diagnosed with MS. METHODS: Participants newly diagnosed with MS (i.e., ≤ 2 years; n = 152) completed an online Qualtrics survey that assessed PA levels and COM-B constructs. Multivariate Analysis of Variance and Discriminant Function Analysis identified the constructs that differentiated PA groups. RESULTS: The results indicated that 39.5% and 34.2% of the sample were classified as Insufficiently Active and Not Regularly Active, respectively. The results further identified Intention, Action Control, Action Self-efficacy, Action Planning, Outcome Expectation, Goal Setting, and Recovery Self-efficacy, and Fatigue as the primary correlates of PA in persons newly diagnosed with MS. CONCLUSIONS: Our results identified COM-B constructs in the Capability and Motivation domains as the primary correlates of physical activity in persons newly diagnosed with MS. Such research might inform interventions for changing physical activity in this MS subpopulation.

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.

Sedentary Behavior and Lower-Extremity Physical Function across the Lifespan of Adults with Multiple Sclerosis.

One outcome of aging with multiple sclerosis (MS) involves the decline in physical function, including compromised balance, reduced walking speed, and lower-extremity strength. Sedentary behavior, the other end of the activity continuum, may be targeted for improvements in physical function among adults with MS, but less is known about the relationship between sedentary behavior and physical function with increasing age in MS. This study examined the associations between device-measured volume and pattern of sedentary behavior and physical function based on SPPB (Short Physical Performance Battery) of ambulatory persons with MS across the lifespan. We categorized participants (N = 216) into young (20-39 years), middle-aged (40-59 years), and older (60-79 years) age groups. Participants completed the SPPB during a single visit to the laboratory and wore an accelerometer for a 7-day period. The one-way analysis of variance indicated no differences in volume and pattern of sedentary behavior among the three age groups, except for average sedentary bout length. Spearman bivariate correlations indicated that pattern, but not volume, of sedentary behavior was associated with physical function in young, middle-aged, and older adults, and the magnitude of these associations varied by age group. Future interventions may reduce and break up prolonged periods of sedentary behavior for improvements in physical function and possibly other consequences in persons with 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.

Association of disease outcomes with physical activity in multiple sclerosis: A cross-sectional study.

Purpose/Objective Research: This study examined combinations of disease outcomes (i.e., walking, cognition, and symptoms) as correlates of physical activity subgroups (insufficiently active vs. sufficiently active) in persons with multiple sclerosis (MS). RESEARCH METHOD/DESIGN: This study included 213 participants who completed walking and cognitive function tests and self-report measures of symptoms and physical activity. Multivariate analysis of variance and discriminant function analysis identified combinations of MS outcomes associated with physical activity. RESULTS: The sample had a mean age of 49.6 years (SD = 13.2), a 3:1 female:male ratio, and a Patient Determined Disease Steps median (interquartile range) score of 1.0 (3.0). Multivariate analysis of variance demonstrated that MS outcome clusters were significantly associated with physical activity, namely walking (i.e., Six-Minute Walk, Timed Up and Go, and MS Walking Scale), Pillai's trace V = .16, F(3, 180) = 11.43, η² = .16; cognition (i.e., Symbol Digits Modalities Test, California Verbal Learning Test-Second Edition, Brief Visuospatial Memory Test-Revised), Pillai's trace V = .04, F(3, 204) = 2.79, η² = .04; and symptoms (i.e., fatigue, anxiety, depression, and pain), Pillai's trace V = .16, F(4, 199) = 9.30, η² = .16. Discriminant function analysis indicated that a significant discriminant function of walking endurance and walking limitations, depression, fatigue, and processing speed was associated with physical activity subgroups. CONCLUSION/IMPLICATIONS: The findings identified walking endurance and limitations, processing speed, depression, and fatigue as primary correlates of physical activity differences in persons with MS. These results may inform researchers and health care providers to consider these factors in behavior change interventions and clinical practices for promoting adequate physical activity levels in MS. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Social Cognitive Theory variables as correlates of physical activity in fatigued persons with multiple sclerosis.

BACKGROUND: There is interest in the application of behavioral interventions based on theory for increasing physical activity among adults with multiple sclerosis (MS). To date, researchers have applied theory such as Social Cognitive Theory (SCT) for identifying correlates of physical activity that can then inform the design and delivery of behavioral interventions. Such research often has been conducted in heterogeneous samples of persons with MS without a focus on those with a specific symptom, such as fatigue, that may be targeted by physical activity behavioral interventions. To that end, this study examined SCT variables (i.e., self-efficacy, barriers, outcome expectations, goal-setting, planning, social support, and functional limitations) as correlates of physical activity in persons with MS who self-reported elevated fatigue. METHODS: Persons with MS (N=210; aged 49.6[13.2] years) who ambulated with or without assistance participated in the study. Participants completed self-report measures of fatigue, physical activity, and SCT variables and wore an ActiGraph GT3X+ accelerometer on a belt around the waist for 7 days. The accelerometer data were processed and delineated into time spent in light and moderate-to-vigorous physical activity (MVPA) based on MS-specific cut-points. We generated groups of fatigued (n=134) and non-fatigued (n=76) persons with MS based on the cut-off score of 4 for the Fatigue Severity Scale. RESULTS: There were differences in physical activity and SCT variables between fatigued and non-fatigued persons with MS. Among those with fatigue, functional limitations (ρ=0.52), self-efficacy (ρ=0.31), and goal-setting (ρ=0.25) were associated with device-measured MVPA, and all SCT variables except outcome expectations were associated with self-reported physical activity. The regression analyses indicated self-efficacy, functional limitations, and goal-setting as significant correlates of MVPA in those with fatigue. CONCLUSION: Self-efficacy, goal-setting, and social support may be important targets of SCT-based behavioral interventions for increasing physical activity among persons with MS who have fatigue.