Free-Living Physical Activity and Sedentary Behaviour in Autoimmune Myasthenia Gravis: A Cross-Sectional Study.

BACKGROUND: Muscle weakness and fatigability, the prominent symptoms of autoimmune myasthenia gravis (MG), negatively impact daily function and quality of life (QoL). It is currently unclear as to what extent symptoms limit activity and whether physical activity (PA) behaviours are associated with reduced QoL. OBJECTIVES: This study aimed to describe habitual PA patterns and explore relationships between PA metrics, clinical MG characteristics, and health-related QoL (HRQoL). METHODS: PA data from a tri-axial trunk accelerometer worn for seven days, was collected from females with generalized, stable MG and compared to control subjects. MG-specific evaluations, the six-minute walk test and knee extension strength were assessed in individuals with MG (IwMG). Mann-Whitney tests were used to study between-group differences. Spearman rank correlation coefficient was performed to explore relationships between variables. RESULTS: Thirty-three IwMG (mean (SD) age 45 (11) years) and 66 control subjects were included. IwMG perform less vigorous-intensity PA than control subjects (p = 0.001), spend more time sedentary (p = 0.02) and engage in less and shorter durations of moderate-vigorous-intensity PA (MVPA). For IwMG, habitual PA correlated positively with 6 min walking distance (rho = 0.387, p = 0.029) and negatively with body mass index (rho = -0.407, p = 0.019). We did not find any association between PA or sedentary behaviour and; HRQoL, symptom severity nor lower limb strength. CONCLUSIONS: Individuals with stable MG perform less PA, at lower intensities, and are more inactive than control individuals. Further research is warranted to understand factors influencing PA patterns in MG and whether interventions could be successful in increasing PA quantity and intensity in IwMG.

Changes in Cardiorespiratory Fitness After Gastric Bypass: Relations with Accelerometry-Assessed Physical Activity.

BACKGROUND: Exercise training optimizes cardiorespiratory fitness (CRF) after bariatric surgery, but the effect of spontaneous physical activity is not well known. This study aimed to objectively quantify changes in CRF and habitual physical activity 6 months after bariatric surgery and to examine whether change in CRF was related to change in physical activity. METHODS: Secondary analyses were performed on data from women who underwent Roux-en-Y gastric bypass (RYGB) between 2010 and 2014. Measurements were performed before and 6 months after RYGB and included V̇O2peak (graded maximal exercise test on a cycle ergometer), habitual physical activity (Actigraph GT3x accelerometer worn during 7 days), and body composition (DXA absorptiometry). Changes after RYGB were analyzed using Wilcoxon signed-rank test. Relations between change in CRF and change in physical activity were analyzed with Spearman correlations adjusted on age and preoperative BMI. RESULTS: Forty-five women (median [P25-P75] age, 43.0 [38.0-51.0] year; BMI, 42.6 [40.0-45.5] kg/m2) were included. Mean (SD) weight loss 6 months after RYGB was - 27.5 (7.9) kg (P < 0.001). Absolute V̇O2peak decreased by 0.35 (0.50) L/min (P < 0.001) and relative V̇O2peak tended to increase by 1.7 (5.3) mL/kg/min (P = 0.06), both with large inter-individual variability. Based on objective accelerometry data, daily steps and moderate-to-vigorous physical activity increased by 1275 (3164) steps/day and 7.6 (19.3) min/day, respectively (both P < 0.05). Change in absolute V̇O2peak was positively related to change in moderate-to-vigorous physical activity (r = 0.35; P = 0.03). CONCLUSIONS: The decrease in absolute CRF observed 6 months after RYGB might be prevented by increasing habitual physical activity. TRIAL REGISTRATION: clinicaltrials.gov identifier: NCT01113996.

Marathons and myasthenia gravis: a case report.

BACKGROUND: The cardinal symptoms of auto-immune myasthenia gravis are fatigue and weakness. Endurance events such as marathon running would seem incompatible with this chronic disease. Many patients stop sport altogether. There is limited literature of patients with auto-immune myasthenia gravis undergoing regular endurance exercise. CASE PRESENTATION: We report the case of a 36-year-old female who began long-distance running whilst experiencing initial symptoms of myasthenia gravis. She was diagnosed with auto-immune myasthenia gravis and whilst advised to stop all sport, her way of fighting and living with this chronic and unpredictable disease was to continue running to maintain a healthy body and mind. Despite suffering from ocular, bulbar and localized limb fatigability, she managed to complete multiple marathons and achieve disease stability with cholinesterase inhibitors. CONCLUSIONS: Marathon and half-marathon running lead to distinct changes in mediators of inflammation in an exercise-dose-dependent manner. Despite symptoms of weakness and fatigue in certain muscles in myasthenia gravis, physical exertion remains possible and may not worsen symptoms as demonstrated in this case and recent studies. The immunomodulatory role of exercise could be considered in this case however this hypothesis remains to be confirmed in future studies with quantitative data.

The benefits and tolerance of exercise in myasthenia gravis (MGEX): study protocol for a randomised controlled trial.

BACKGROUND: Research exploring the effects of physical exercise in auto-immune myasthenia gravis (MG) is scarce. The few existing studies present methodological shortcomings limiting the conclusions and generalisability of results. It is hypothesised that exercise could have positive physical, psychological as well as immunomodulatory effects and may be a beneficial addition to current pharmacological management of this chronic disease. The aim of this study is to evaluate the benefits on perceived quality of life (QOL) and physical fitness of a home-based physical exercise program compared to usual care, for patients with stabilised, generalised auto-immune MG. METHODS: MGEX is a multi-centre, interventional, randomised, single-blind, two-arm parallel group, controlled trial. Forty-two patients will be recruited, aged 18-70 years. Following a three-month observation period, patients will be randomised into a control or experimental group. The experimental group will undertake a 40-min home-based physical exercise program using a rowing machine, three times a week for three months, as an add-on to usual care. The control group will receive usual care with no additional treatment. All patients will be followed up for a further three months. The primary outcome is the mean change in MGQOL-15-F score between three and six months (i.e. pre-intervention and immediately post-intervention periods). The MGQOL-15-F is an MG-specific patient-reported QOL questionnaire. Secondary outcomes include the evaluation of deficits and functional limitations via MG-specific clinical scores (Myasthenia Muscle Score and MG-Activities of Daily Living scale), muscle force and fatigue, respiratory function, free-living physical activity as well as evaluations of anxiety, depression, self-esteem and overall QOL with the WHO-QOL BREF questionnaire. Exercise workload will be assessed as well as multiple safety measures (ECG, biological markers, medication type and dosage and any disease exacerbation or crisis). DISCUSSION: This is the largest randomised controlled trial to date evaluating the benefits and tolerance of physical exercise in this patient population. The comprehensive evaluations using standardised outcome measures should provide much awaited information for both patients and the scientific community. This study is ongoing. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02066519 . Registered on 13 January 2014.

Translation, cross-cultural adaptation, and validation of the french version of the 15-item Myasthenia Gravis Quality Of life scale.

INTRODUCTION: Evaluation of quality of life (QOL) has become essential in healthcare. Currently no MG-specific QOL measure exists in French. The aim of this study was to translate, culturally adapt, and evaluate the psychometric properties of the French version of the 15-Item Myasthenia Gravis Quality of Life Scale (MG-QOL15) scale for French myasthenia patients. METHODS: Translation and cross-cultural adaption of the MG-QOL15 was performed, followed by reliability and validity evaluations. RESULTS: One hundred and twenty-five patients were included. Internal consistency was excellent (Cronbach α = 0.92) as was test-retest reliability (ICC = 0.92, 95% CI 0.86-0.96). Concurrent validity was good for both clinical scores (myasthenic muscle score: ρ = -0.52, P < 0.001; Myasthenia Gravis-Activities of Daily Living scale score: ρ = 0.62, P < 0.001). Correlations were strongest for overall QOL (ρ = 0.62, P < 0.001) and physical health (ρ = 0.67, P < 0.001) on the World Health Organization Quality of Life short score (WHO-QOL BREF). CONCLUSION: The French version of the MG-QOL15 is valid and reliable and is now available for use with French-speaking patients. Muscle Nerve, 2016 Muscle Nerve 55: 639-645, 2017.