Perioperative risk and benefit of antiplatelet therapy in patients undergoing non-cardiac surgery within 1 year after percutaneous coronary intervention with second-generation drug-eluting stents

Background

Antiplatelet therapy (APT) in patients undergoing non-cardiac surgery (NCS) after percutaneous coronary intervention (PCI) is still on debate due to its opposite effects which are to prevent from cardiovascular events and to cause bleeding. There is no apparent consensus on how to determine perioperative APT strategy within 1 year after PCI. Therefore, we investigated the risk and benefit of APT in NCS within 1 year after PCI.

Methods

Patients undergoing NCS after PCI with second-generation drug-eluting stents are retrospectively included from multicenter cohort of 8 medical centers in Korea. Perioperative clinical event within 30 days after NCS was recorded. Net adverse clinical event (NACE) including all cause death, major adverse cardiac event (MACE, a composite of cardiac death, myocardial infarction, and stent thrombosis) and major bleeding were evaluated. To overcome bias, propensity score covariate adjustment was performed using logistic regression analysis to generate propensity scores for patients of both APT strategies.

Results

Total 1130 patients (median age 69 years, female 30.5%) undergoing NCS within 1 year after PCI were eligible in the cohort. Study population included 55.1% patients suffered from ACS and 22.5% underwent complex PCI. NCS included 45.8% intermediate-to-high risk surgery and 10.7% urgent or emergent surgery. APT was continued during NCS in 62.7% of the patients. More patients continued DAPT (48% vs. 32%, p<0.001) among the patients who underwent NCS within 6 months after PCI than those who underwent NCS after 6 months. There were 49 NACE (4.3%), 16 MACE (1.4%) and 23 major bleeding events (2.0%), respectively. Continuing APT was associated with a lower risk of NACE (Adjusted hazard ratio [HR], 0.49; 95% confidence interval [CI], 0.27–0.89; p=0.020)) and MACE (Adjusted HR, 0.35; 95 CI, 0.12–0.96; p=0.042). Subgroup analysis showed a tendency that continuing APT might be favorable than discontinuing APT in terms of MACE in patients who were diagnosed with ACS, underwent complex PCI, or underwent NCS within 6 months after PCI.

Conclusions

About two thirds of the patients were continuing APT during NCS. Our findings may support a careful consideration of APT continuation for some of the patients who are undergoing NCS within 1 year after PCI.

Funding Acknowledgement

Type of funding sources: None.

18F-FDG-PET in guided dose-painting with intensity modulated radiotherapy in oropharyngeal tumours: A phase I study (FiGaRO)

BACKGROUND AND PURPOSE

The FiGaRO trial assessed the feasibility and safety of using an FDG-PET-based dose-painting technique to deliver a radiotherapy (RT) boostto the FDG-avid primary tumour in patients with locally advanced high and intermediate risk oropharyngeal cancer.

MATERIALS AND METHOD

Patients underwent a planning 18FDG-PET-CT scan, immobilised in the treatment position, after one cycle of induction chemotherapy. The volume of persistent FDG-avidity in the primary tumour was escalated to 71.5 Gy in30 fractions delivered using a simultaneous integrated boost Intensity Modulated RT (SIB-IMRT) technique. RT was delivered with concomitant Cisplatin following 2 cycles of induction chemotherapy. The primary outcome was the incidence of grade ≥ 3 late mucosal toxicity 12 months post-treatment, with an excess rate of >10% regarded as unacceptable.

RESULTS

Twenty-nine patients were included and twenty-four were treated between 2014 and 2018, in two UK centres. Median follow-up was 36 months (range 4-56 months). Pre-defined planning target volume objectives and organ at risk dose constraints were met in all cases. There were no incidents of acute grade 4 toxicity. There were 4 cases of grade ≥ 3 mucosal toxicity at 12 months post-treatment (19.1%). There were no cases of persistent mucosal ulceration at 12 months. Overall survival at 3-years was 87.5%, 92.9% for intermediate and 70.0% for high risk patients.

CONCLUSION

Late toxicity rates, although higher than anticipated, are comparable to contemporary published data for standard dose chemo-IMRT. Results suggest improved 3y survival rates for high risk patients. This approach merits further investigation. ClinicalTrials.gov Identifier: NCT02953197.

Comparative identification, nutritional, and physiological regulation of chicken liver-enriched genes

The liver performs a number of vital functions in the chicken. In order to identify unique gene expression patterns and link them to potential functions in the chicken liver, genes enriched in the liver of chickens needed to be investigated in a comparative manner. In this study, 41 liver-enriched genes were identified through chicken microarray, and many of them were validated through comparative analysis of mice and humans. Thirteen of them were unique in chickens, and their liver enhancement was confirmed by reverse transcription PCR. Furthermore, the expression of those 13 chicken liver-enriched genes was investigated, in response to nutritional and physiological challenges. Real-time PCR revealed that expression of PIT54 (P < 0.01), phosphoribosyl pyrophosphate synthetase 2 (PRPS2) (P < 0.05), sulfotransferase (SULT) (P < 0.05), and cytochrome P450 family 2 subfamily C, polypeptide 18 (CYP2C18) (P < 0.05) were significantly decreased in the liver during fasting compared to ad libitum control. During the post-laying stage, expression of GAL8 was significantly increased (P < 0.01), but CYP2C18 expression was significantly reduced (P < 0.05). Liver-enriched genes that were identified in this study and their expression patterns under fasting and the post-laying stage will serve as future targets to gain a better understanding of liver physiology, function and development in poultry.

Improving anti-bullying laws and policies to protect youth from weight-based victimization: parental support for action

BACKGROUND

Weight-based bullying is a prevalent problem among youth with overweight and obesity, but remains neglected in existing policy-level strategies to address youth bullying. Parental support is an influential catalyst motivating political will for policy decisions affecting youth, but has received limited research attention.

OBJECTIVES

To assess levels of, and predictors of, parental support for school-based policies and state/federal legal measures to address weight-based bullying in 2014 and 2015.

METHODS

Identical online questionnaires were completed by two independent national samples of parents in 2014 and 2015 (N = 1804).

RESULTS

Parental support for all policy actions was high (at least 81%) and significantly increased from 2014 to 2015 for legal measures that would a) require state anti-bullying laws to add protections against weight-based bullying, and b) enact a federal anti-bullying law that includes weight-based bullying.

CONCLUSIONS

These findings can inform policy discourse about remedies for youth bullying, and suggest that parental support for improved legal protections against weight-based bullying is present, consistent, and strong.

Legislating for weight-based equality: national trends in public support for laws to prohibit weight discrimination

The prevalence of weight discrimination in the United States has led to increasing calls for legal measures to address weight-based inequities on a broader scale. This study examined public support in 2014 and 2015 for three proposed laws prohibiting weight discrimination, and compared findings with public attitudes towards the same laws from 2011 to 2013. An online survey was completed by a diverse national sample of US adults (N=2411) in June-July of 2014 and 2015 to assess their support for anti-discrimination legislation. Public support increased for the anti-discrimination laws from 2014 to 2015, and at least 71% of participants expressed support for each of the laws in both years. Compared with public support documented in 2011-2013, there was a significant increase in support in 2014-2015 for legislation to extend disability protections to individuals with obesity and for laws that would include body weight in existing state civil rights statutes. Consistently, high levels of support (78%) were documented across this 5-year period for laws to address weight-based discrimination in employment. As public approval is a powerful catalyst motivating political will needed to make policy changes, these findings provide important insights and implications for advancing policy-level discourse about remedies for weight discrimination.

Radiation promotes invasiveness of non-small-cell lung cancer cells through granulocyte-colony-stimulating factor

Despite ionizing radiation (IR) is being widely used as a standard treatment for lung cancer, many evidences suggest that IR paradoxically promotes cancer malignancy. However, its molecular mechanisms underlying radiation-induced cancer progression remain obscure. Here, we report that exposure to fractionated radiation (2 Gy per day for 3 days) induces the secretion of granulocyte-colony-stimulating factor (G-CSF) that has been commonly used in cancer therapies to ameliorate neutropenia. Intriguingly, radiation-induced G-CSF promoted the migratory and invasive properties by triggering the epithelial-mesenchymal cell transition (EMT) in non-small-cell lung cancer cells (NSCLCs). By irradiation, G-CSF was upregulated transcriptionally by β-catenin/TCF4 complex that binds to the promoter region of G-CSF as a transcription factor. Importantly, irradiation increased the stability of β-catenin through the activation of PI3K/AKT (phosphatidylinositol 3-kinase/AKT), thereby upregulating the expression of G-CSF. Radiation-induced G-CSF is recognized by G-CSFR and transduced its intracellular signaling JAK/STAT3 (Janus kinase/signal transducers and activators of transcription), thereby triggering EMT program in NSCLCs. Taken together, our findings suggest that the application of G-CSF in cancer therapies to ameliorate neutropenia should be reconsidered owing to its effect on cancer progression, and G-CSF could be a novel therapeutic target to mitigate the harmful effect of radiotherapy for the treatment of NSCLC.

Body composition and physical function in women with multiple sclerosis

Persons with multiple sclerosis (MS) have reduced physical activity (PA) and lower-limb physical function and potentially disordered body composition compared with their peers without MS. The aim of this study was to determine whether PA and body composition were differentially associated with lower-limb physical function in persons with MS compared with controls. Females with MS and age- and body mass index-matched female controls (n = 51; average age 48.1 +/- 9.7 yr) were measured for PA with daily step counts, relative fat mass (%Fat), and leg lean mass (LM-LEG) via dual energy X-ray absorptiometry and for lower-limb physical function with objective performance tests. Persons with MS had 12.5% to 53% poorer lower-limb physical function than controls (all p < 0.05). PA, %Fat, and LM-LEG to body mass ratio (LM-LEG/BM) were associated with lower-limb physical function in both persons with MS and controls (all p < 0.05). Based on median splits, higher %Fat, lower LM-LEG/BM, and MS conferred poorer lower-limb physical function (all p < 0.05). PA, %Fat, and LM-LEG/BM were associated with lower-limb physical function, suggesting that body composition, specifically reducing adiposity and increasing lean mass and/or increasing PA levels, may be a potential target for MS interventions.

Novel signaling axis for ROS generation during K-Ras-induced cellular transformation

Reactive oxygen species (ROS) are well known to be involved in oncogene-mediated cellular transformation. However, the regulatory mechanisms underlying ROS generation in oncogene-transformed cells are unclear. In the present study, we found that oncogenic K-Ras induces ROS generation through activation of NADPH oxidase 1 (NOX1), which is a critical regulator for the K-Ras-induced cellular transformation. NOX1 was activated by K-Ras-dependent translocation of p47(phox), a subunit of NOX1 to plasma membrane. Of note, PKCδ, when it was activated by PDPK1, directly bound to the SH3-N domain of p47(phox) and catalyzed the phosphorylation on Ser348 and Ser473 residues of p47(phox) C-terminal in a K-Ras-dependent manner, finally leading to its membrane translocation. Notably, oncogenic K-Ras activated all MAPKs (JNK, ERK and p38); however, only p38 was involved in p47(phox)-NOX1-dependent ROS generation and consequent transformation. Importantly, K-Ras-induced activation of p38 led to an activation of PDPK1, which then signals through PKCδ, p47(phox) and NOX1. In agreement with the mechanism, inhibition of p38, PDPK1, PKCδ, p47(phox) or NOX1 effectively blocked K-Ras-induced ROS generation, anchorage-independent colony formation and tumor formation. Taken together, our findings demonstrated that oncogenic K-Ras activates the signaling cascade p38/PDPK1/PKCδ/p47(phox)/NOX1 for ROS generation and consequent malignant cellular transformation.

The impact of gait disability on the calibration of accelerometer output in adults with multiple sclerosis

Accelerometer activity counts have been correlated with energy expenditure during treadmill walking among ambulatory adults with multiple sclerosis (MS). This study examined the effects of gait disability on 1) the association between rates of energy expenditure and accelerometer output in overground walking and 2) the calibration of accelerometer output for quantifying time spent in moderate-to-vigorous physical activity (MVPA) in people with MS. The sample consisted of 24 individuals with MS, of whom 10 reported gait disability based on Patient-Determined Disease Steps (PDDS) scores. The participants undertook three 6-minute periods of overground walking while wearing an accelerometer and a portable metabolic unit (K4b2, Cosmed, Rome, Italy). In the first period of walking, the participants walked at a self-selected, comfortable speed. In the two subsequent walking periods, participants walked at speeds above and below (±0.5 mph) the comfortable walking speed, respectively. Strong linear relationships were observed between rates of accelerometer activity counts and energy expenditure during walking in the overall sample (R(2) = 0.90) and subsamples with (R(2) = 0.88) and without gait disability (R(2) = 0.91). The slope of the relationship was significantly steeper in the subsample with gait disability (β= 0.0049) than in the subsample without gait disability (β= 0.0026). The difference in slopes resulted in a significantly lower cut-point for MVPA (1886 vs. 2717 counts/min) in those with gait disability. These findings provide a metabolic cut-point for quantifying time spent in MVPA in people with MS, both with and without gait disability.

Gait and six-minute walk performance in persons with multiple sclerosis

The six-minute walk (6 MW) has been established as a clinic-based, performance measure of walking endurance that reflects community ambulation in multiple sclerosis (MS). Consequently, identifying the contribution of variables to 6 MW performance may provide targets for improving real-life walking in MS, and these variables may differ as a function of disability. This study examined cadence and stride length as gait variables that explain differences in 6 MW performance between persons with MS and controls, and by level of disability. 256 community-residing persons with MS and 49 non-MS controls performed a standard 6 MW test and completed 2 trials of comfortable walking on an electronic walkway for quantifying gait. Regression analyses indicated that cadence and stride length explain differences in 6 MW performance between MS and controls, and by level of disability in MS. The contribution of cadence and stride length to walking endurance differed as a function of disability, such that cadence and to a greater extent stride length explained variance in 6 MW performance in mild MS, whereas cadence and stride length explained approximately an equivalent amount of variance in 6 MW performance in moderate-to-severe MS. We provide evidence for intervention strategies that are specific to disability level to improve walking endurance in MS.

Further validation of multiple sclerosis walking scale-12 scores based on spatiotemporal gait parameters

OBJECTIVE

To examine the association between Multiple Sclerosis Walking Scale-12 (MSWS-12) scores and spatiotemporal parameters of gait as indicators of gait quality among ambulatory persons with multiple sclerosis (MS).

DESIGN

Cross-sectional study.

SETTING

University research laboratory.

PARTICIPANTS

Community-residing persons with MS (N=268).

INTERVENTION

Not applicable.

MAIN OUTCOME MEASURES

Main outcome measures included the MSWS-12 and spatial and temporal gait parameters (walking speed, cadence, step length, step time, base of support [ie, the distance between 1 footfall and the line of progression of the opposing foot], and percentage of gait cycle spent in double support). Secondary outcomes included the timed 25-foot walk (T25FW), 6-minute walk (6MW), and Patient-Determined Disease Steps scale.

RESULTS

MSWS-12 scores were significantly correlated with walking speed (r=-.59), cadence (r=-.50), step length (r=-.53), step time (r=.46), base of support (r=.29), and percentage of the gait cycle spent in double support (r=.54). MSWS-12 scores further were significantly correlated with T25FW (r=.57) and 6MW (r=-.75) scores.

CONCLUSIONS

Such findings suggest that the MSWS-12 captures aspects of walking quality, assessed as spatiotemporal parameters of gait, in addition to walking speed and endurance in persons with MS.

Steps per day among persons with multiple sclerosis: variation by demographic, clinical, and device characteristics

OBJECTIVES

To identify steps per day in a large sample of persons with multiple sclerosis (MS) and to describe variation by demographic and clinical characteristics and device type.

DESIGN

Cross-sectional design.

SETTING

General community.

PARTICIPANTS

Convenience sample of persons with multiple sclerosis (N=645) recruited from the general community who were ambulatory and relapse free for 30 days. Mean age ± SD of the participants was 46.3 ± 10.6 years old. Participants were mostly women (85%), white (93%), and employed (64%).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURE

Step counts measured by a motion sensor during a 7-day period.

RESULTS

The average value for the entire sample was 5,903 ± 3,185 steps per day. This value varied by demographic and clinical characteristics, but not device type, and indicated that men, participants who were unemployed, had a high school education or less, progressive MS, a longer disease duration, and higher disability were less physically active based on the metric of steps per day.

CONCLUSIONS

This study provides an expected value for average steps per day among persons with MS. Such an expected value for this population is an important first step to help researchers and clinicians interested in improving the overall health of persons with MS through physical activity promotion.

Symptomatic correlates of six-minute walk performance in persons with multiple sclerosis

BACKGROUND

The six-minute walk (6MW) test has been identified as a valid, reliable, and reproducible measure of endurance walking performance that differentiates persons with multiple sclerosis (MS) and controls and correlates with disability and walking impairment.

AIM

This study examined symptoms of fatigue, pain, and depression as correlates of 6MW performance and the possibility that such symptoms would account for the difference in 6MW distance between persons with MS and controls.

DESIGN

Observational.

SETTING

Research laboratory.

POPULATION

Sixty-six persons, 33 with MS and 33 controls matched on age, sex, height, and weight. METHODS. Participants completed the fatigue severity scale (FSS), short-form of the McGill pain questionnaire (SF-MPQ), and depression items of the hospital anxiety and depression scale (HADS-D) and then performed the six-minute walk (6MW) in a rectangular corridor.

RESULTS

There were statistically significant differences between groups in 6MW distance (p = 0.0001) and FSS (P=0.0001) and SF-MPQ (P=0.025), but not HADS-D (P>0.05), scores. 6MW distance was significantly correlated with FSS (P=-0.66), SF-MPQ (P=-0.38), and HADS-D (P=-0.33) scores in the overall sample, but 6MW distance was significantly correlated with only FSS scores in the separate samples of those with MS (P=-0.46) and controls (P=-0.46). Only group (β=0.32) and FSS scores (β=-0.53) explained variance in overall 6MW distance in a hierarchical, linear regression analysis.

CONCLUSION

This study provides new insight into the symptomatic correlates of 6MW performance and identifies fatigue as a possible target of interventions designed to improve walking endurance in MS.

CLINICAL REHABILITATION IMPACT

Clinicians and practitioners might consider targeting fatigue as a method of managing compromised endurance walking in persons with MS.

Temporal myosin heavy chain isoform expression transitions faster in broiler chickens compared with Single Comb White Leghorns

Myosin heavy chain (MyHC), one of the major components in the contractile machinery of skeletal muscle fibers, is found in several isoforms during myogenesis. During chicken development, embryonic, neonatal, and adult MyHC isoforms are expressed. Broiler chickens have been selected for fast and large muscle growth, whereas Single Comb White Leghorn (SCWL) chickens have been selected for egg laying capabilities. This has led to an obvious difference in muscle growth and development with broilers being much larger than SCWL. The objective of this study was to determine if differences in muscle growth and development of SCWL and broilers are associated with differences in temporal expression of MyHC isoforms in skeletal muscle between the 2 breeds. Pectoralis major muscle (PM) was collected from SCWL and broilers at embryonic d 15, 17, and 19 and 1, 5, 11, 20, 27, and 33 d posthatch with n = 3 samples per time point and breed. Western blotting using 3 monoclonal antibodies (EB165, 2E9, and AB8) was performed to compare the expression patterns of embryonic/adult, neonatal, and adult isoforms of MyHC, respectively, for all time points in both SCWL and broiler chickens. Both broiler and SCWL chickens began expressing the neonatal MyHC isoform on d 5; however, SCWL chickens expressed the neonatal isoform much longer than broilers. The SCWL chickens had sustained expression of the neonatal MyHC isoform through d 27, whereas in broiler chickens the neonatal isoform was not expressed at d 20. Pectoralis major tissue from broiler chickens expressed the adult MyHC isoform as early as d 20, whereas the SCWL chickens began expressing the adult isoform later. The rate of transition to neonatal and adult MyHC isoforms in broilers and Leghorns is consistent with the faster maturation and growth of broilers relative to Leghorns. This relationship between faster growth of the PM and the rate of transition of MyHC isoforms within the fast skeletal muscle of the PM may indicate a selection marker for improvement of broiler PM growth.

Physical activity and multiple sclerosis: new insights regarding inactivity

OBJECTIVES

There is increasing recognition that physical activity has beneficial consequences among persons with multiple sclerosis (MS), but there is concern regarding the current degree of physical inactivity in this population because of limitations with previous research and increased recognition of health behaviors in MS. This study compared physical activity levels between large samples of persons with mild MS and matched controls using validated measures of physical activity.

MATERIALS AND METHODS

The sample included 77 cases of MS and 77 controls matched on age, height, weight, and gender. Physical activity was assessed using five measures, namely the Godin Leisure-Time Exercise Questionnaire (GLTEQ), International Physical Activity Questionnaire (IPAQ), and activity counts per day, step counts per day, and time spent in moderate-to-vigorous physical activity (MVPA) per day by accelerometry.

RESULTS

There were statistically significant differences between groups in accelerometer activity counts (t = -3.87, P = 0.0001), accelerometer step counts (t = -4.29, P = 0.0001), time spent in MVPA (t = -2.39, P = 0.01), GLTEQ scores (t = -3.83, P = 0.0001), and IPAQ scores (t = -3.42, P = 0.0001). The average effect size across all five measures was d = -0.59 and indicated that persons with MS overall were moderately less physically active than the matched controls.

CONCLUSIONS

The primary finding was a moderate reduction in physical activity among those with MS, but the magnitude was substantially smaller than reported in a published meta-analysis. Importantly, the degree of physical inactivity can likely be overcome through the delivery of behavioral interventions for increasing physical activity and this should translate into meaningful consequences for persons with MS.

Accelerometer output and its association with energy expenditure in persons with multiple sclerosis

Limited data support the strong association between rates of accelerometer activity counts and energy expenditure during dynamic activity in persons with multiple sclerosis (MS). This study examined the association between rates of activity counts and energy expenditure during walking by using two models of accelerometers and generated cut-points representing moderate-to-vigorous physical activity (MVPA) in persons with MS. Participants were 43 persons with MS and 43 controls who undertook 5 min of seated rest and up to five 6 min periods of walking at five different speeds on a treadmill. While walking, participants wore two models of accelerometers and a mouthpiece in-line with an open-circuit spirometry system for measuring energy expenditure (rate of oxygen consumption). Strong linear associations were found between accelerometer activity counts and energy expenditure, and the magnitude did not differ between MS and controls for both accelerometer models. The mean slopes of the linear relationships were steeper in persons with MS than controls and resulted in distinct cut-points for MVPA based on accelerometer counts for persons with MS and controls. The strong linear relationship between activity counts and energy expenditure and cut-points for quantifying time spent in MVPA should allow for better understanding of physical activity and examination of its predictors and consequences when using accelerometers in MS.

Energy cost of walking and its association with gait parameters, daily activity, and fatigue in persons with mild multiple sclerosis

BACKGROUND

Energy cost of walking (C(w)) is elevated in persons with multiple sclerosis (MS), perhaps because of gait impairment, and may impact daily activity and fatigue.

OBJECTIVE

The authors examined for associations between C(w), spatiotemporal gait parameters, daily activity, and perceived fatigue in persons with mild MS.

METHODS

Forty-four participants completed 4 trials of walking on a GAITRite mat and one 6-minute trial of walking on a treadmill at a constant, controlled speed of 54 m min(-1) while expired gases were analyzed for oxygen consumption. Participants also completed the Fatigue Severity Scale (FSS) and wore a waist-mounted accelerometer for 7 days.

RESULTS

C (w) was significantly and inversely associated with gait speed (r = -.25) and stride length (r = -.32) and positively associated with double limb support (r = .27). C (w) was significantly and inversely associated with daily accelerometer activity counts (r = -.35) and positively associated with FSS scores (ρ = .31).

CONCLUSION

The results support the development and application of rehabilitation strategies to address impaired gait parameters as an approach to improve C(w), daily activities, and fatigue.

Physical activity, self-efficacy, and health-related quality of life in persons with multiple sclerosis: analysis of associations between individual-level changes over one year

BACKGROUND

Physical activity and self-efficacy represent behavioral and psychological factors, respectively, that are compromised in persons with multiple sclerosis (MS), but might be modifiable through intervention and result in better health-related quality of life (HRQOL).

PURPOSE

The present study adopted a panel research design and examined the associations between individual-level changes in physical activity, self-efficacy, and HRQOL over a one-year period in persons with MS.

METHOD

The sample consisted of 269 persons with relapsing-remitting MS who completed the Godin Leisure-Time Questionnaire (GLTEQ), Multiple Sclerosis Self-Efficacy (MSSE) Scale, and Multiple Sclerosis Quality of Life-29 (MSIS-29) Scale on two occasions that were separated by 1 year. The data were analyzed using panel analysis in Mplus 3.0.

RESULTS

The initial panel analysis indicated that individual-level change in physical activity was associated with individual-level change in both physical and psychological HRQOL. The subsequent panel analysis indicated that (a) individual-level change in self-efficacy for functioning with MS was associated with individual-level change in physical HRQOL, whereas individual-level change in self-efficacy for control was associated with individual-level change in psychological HRQOL; (b) individual-level change in self-efficacy for functioning with MS, but not self-efficacy for control, mediated the association between individual-level change in physical activity and physical HRQOL; and (c) individual-level change in self-efficacy for controlling MS was the strongest predictor of individual-level change in HRQOL.

CONCLUSION

Physical activity and self-efficacy both might be important targets of subsequent behavioral and self-management interventions for improving the HRQOL of persons with MS, although self-efficacy is seemingly more important than physical activity.

Evidence for the different physiological significance of the 6- and 2-minute walk tests in multiple sclerosis

BACKGROUND

Researchers have recently advocated for the 2-minute walk (2MW) as an alternative for the 6-minute walk (6MW) to assess long distance ambulation in persons with multiple sclerosis (MS). This recommendation has not been based on physiological considerations such as the rate of oxygen consumption (V·O2) over the 6MW range.

OBJECTIVE

This study examined the pattern of change in V·O2 over the range of the 6MW in a large sample of persons with MS who varied as a function of disability status.

METHOD

Ninety-five persons with clinically-definite MS underwent a neurological examination for generating an Expanded Disability Status Scale (EDSS) score, and then completion of the 6MW protocol while wearing a portable metabolic unit and an accelerometer.

RESULTS

There was a time main effect on V·O2 during the 6MW (p=.0001) such that V·O2 increased significantly every 30 seconds over the first 3 minutes of the 6MW, and then remained stable over the second 3 minutes of the 6MW. This occurred despite no change in cadence across the 6MW (p=.84).

CONCLUSIONS

The pattern of change in V·O2 indicates that there are different metabolic systems providing energy for ambulation during the 6MW in MS subjects and steady state aerobic metabolism is reached during the last 3 minutes of the 6MW. By extension, the first 3 minutes would represent a test of mixed aerobic and anaerobic work, whereas the second 3 minutes would represent a test of aerobic work during walking.

Accuracy of the actibelt(®) accelerometer for measuring walking speed in a controlled environment among persons with multiple sclerosis

BACKGROUND

Advances in portable sensor technology have opened an era for objective, real-life monitoring of walking speed in persons with multiple sclerosis (MS).

PURPOSE

The present study examined the accuracy of the actibelt(®) accelerometer for measuring walking speed during a standard 6-min walk (6MW) and the possibility that disability status influenced the degree of accuracy among persons with MS.

METHODS

On a single testing session, 51 persons with MS and Expanded Disability Status Scale scores between 2.0 and 6.5 performed a 6MW while wearing an actibelt(®) in the body's sagittal symmetry plane and close to the body's centre of mass.

RESULTS

All 51 participants completed the 6MW without stopping, falling, or any adverse events, and the actibelt(®) provided walking speed data for each of the participants. The actibelt(®) significantly overestimated walking speed (actual minus actibelt(®)) by a mean±standard deviation of -0.12±0.17 m/s for the overall sample (p<0.0001). There was no significant overestimation in the sample with mild disability (-0.02±0.11 m/s), but there was in the samples with moderate (-0.10±0.16 m/s) and severe (-0.26±0.12 m/s) disability.

CONCLUSION

The actibelt(®) is ready for real-life monitoring of walking speed in persons with mild MS, but caution is necessary when interpreting the accuracy of the walking speed data for those with MS who have moderate and severe disability.

Mobility, balance and falls in persons with multiple sclerosis

BACKGROUND

There is a lack of information concerning the relation between objective measures of gait and balance and fall history in persons with MS (PwMS). This investigation assessed the relation between demographic, clinical, mobility and balance metrics and falls history in persons with multiple sclerosis (MS).

METHODS

52 ambulatory persons with MS (PwMS) participated in the investigation. All persons provided demographic information including fall history over the last 12 months. Disease status was assessed with Expanded Disability Status Scale (EDSS). Walking speed, coordination, endurance and postural control were quantified with a multidimensional mobility battery.

RESULTS

Over 51% of the participants fell in the previous year with 79% of these people being suffering recurrent falls. Overall, fallers were older, had a greater prevalence of assistive devices use, worse disability, decreased walking endurance, and greater postural sway velocity with eyes closed compared to non-fallers. Additionally, fallers had greater impairment in cerebellar, sensory, pyramidal, and bladder/bowel subscales of the EDSS.

CONCLUSIONS

The current observations suggest that PwMS who are older, more disabled, utilize an assistive device, have decreased walking coordination and endurance and have diminished balance have fallen in the previous year. This suggests that individuals who meet these criteria need to be carefully monitored for future falls. Future research is needed to determine a prospective model of falls specific to PwMS. Additionally, the utility of interventions aimed at reducing falls and fall risk in PwMS needs to be established.