Muscle carnosine in experimental autoimmune encephalomyelitis and multiple sclerosis

BACKGROUND: Muscle carnosine is related to contractile function (Ca++ handling) and buffering of exercise-induced acidosis. As these muscular functions are altered in Multiple Sclerosis (MS) it is relevant to understand muscle carnosine levels in MS. METHODS: Tibialis anterior muscle carnosine was measured in an animal MS model (EAE, experimental autoimmune encephalomyelitis, n = 40) and controls (CON, n = 40) before and after exercise training (EAEEX, CONEX, 10d, 1 h/d, 24 m/min treadmill running) or sedentary conditions (EAESED, CONSED). Human m. vastus lateralis carnosine of healthy controls (HC, n = 22) and MS patients (n = 24) was measured. RESULTS: EAE muscle carnosine levels were decreased (p < .0001) by ~ 40% to ~ 64% at 10d and 17d following EAE induction (respectively) regardless of exercise (p = .823). Similarly, human MS muscle carnosine levels were decreased (- 25%, p = .03). CONCLUSION: Muscle carnosine concentrations in an animal MS model and MS patients are substantially reduced. In EAE exercise therapy does not restore this

Bewegungstraining bei Patienten mit chronischen Atemwegserkrankungen: Werden kardiovaskuläre Komorbiditäten und Outcomes berücksichtigt? Eine systematische Übersichtsarbeit

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Acute Responses of Cytokines and Adipokines to Aerobic Exercise in Relapsing vs. Remitting Women with Multiple Sclerosis

Objective: To examine the acute effect of exercise on cytokines and adipokines during relapse and the remitting phase of multiple sclerosis (MS). Methods: Thirty women with MS in the relapsing or remitting phase were matched with fifteen healthy controls. Participants performed a single-bout of aerobic exercise at 60-70% maximal heart rate. Furthermore, five women in the relapsing phase were enrolled (control relapse) and did not receive any intervention. Blood samples were taken before, immediately after, 1-hour and 6-hours after the exercise. Results: Levels of IL-10 and TNF-α in response to exercise were similar in healthy and MS remitting subjects. Compared to baseline, TNF-α levels in relapsing subjects were significantly decreased immediately after exercise. Immediately following exercise, leptin levels significantly decreased in relapsing subjects. Adiponectin and IL-6 showed no significant difference between groups. Conclusion: After relapse, exercise does not induce inflammatory cytokine response and temporarily improves both cytokine and adipokine balance

Periodized home-based training : a new strategy to improve high intensity exercise therapy adherence in mildly affected patients with multiple sclerosis

Introduction: Although high intensity exercise therapy (HIT) in Multiple Sclerosis (MS) induces substantial effects, longer term compliance to such a training program is not evident. When embedded in a periodized, home-based training strategy, high intensity exercise therapy adherence may improve. This is explored first in mildly affected persons with MS. Methods: Exercise capacity (maximal exercise test) and body composition (DEXA) of healthy controls (n = 22) and persons with MS (n = 23, EDSS: 1.9 +/- 1.1) were assessed at baseline (PRE). Next and within the context of an MS awareness project (climbing the Mont Ventoux, France), all participants were enrolled in a 6 m home-based periodized HIT oriented cycling program with remote (Polar (R) M200 activity tracker) supervision. Hereafter, POST measurements were performed similar to baseline. Results: Six months of periodized and home-based HIT oriented training induced improvements in body weight ( - 3%, p = 0.008), BMI ( - 3%, p = 0.01), total mass ( - 2%, p = 0.023), VO2max (+ 5%, p = 0.016), workload (+ 11%, p = 0.001), time until exhaustion (+ 14%, p = 0.001), recovery heart rate (+ 4%, p = 0.04), lactate peak ( + 16%, p = 0.03) and RER (+ 4%, p = 0.04) in MS. Furthermore, all persons with MS safely reached the top of the Mont Ventoux, except for two. Conclusion: The applied 6 m periodized, home-based and HIT-oriented cycling program provided good therapy adherence with similar improvements in exercise capacity compared to healthy controls. Furthermore, this exercise regimen trained mildly-affected persons with MS adequately to climb the Mont Ventoux

Altered muscle oxidative phenotype impairs exercise tolerance but does not improve after exercise training in multiple sclerosis

Background: Patients with multiple sclerosis (MS) experience reduced exercise tolerance that substantially reduces quality of life. The mechanisms underpinning exercise intolerance in MS are not fully clear. This study aimed to determine the contributions of the cardiopulmonary system and peripheral muscle in MS-induced exercise intolerance before and after exercise training. Methods: Twenty-three patients with MS (13 women) and 20 age-matched and sex-matched healthy controls (13 women) performed a cardiopulmonary exercise test. Muscle fibre type composition, size, succinate dehydrogenase (SDH) activity, capillarity, and gene expression and proteins related to mitochondrial density were determined in vastus lateralis muscle biopsies. Nine MS patients (five women) were re-examined following a 12 week exercise training programme consisting of high-intensity cycling interval and resistance training. Results: Patients with MS had lower maximal oxygen uptake compared with healthy controls (V̇O2peak, 25.0 ± 8.5 vs. 35.7 ± 6.4 mL/kg/min, P  0.05). V̇O2peak increased by 23% following exercise training in MS (P  0.05). Conclusions: Skeletal muscle oxidative phenotype (mitochondrial complex I and II content, SDH activity) is lower in patients with MS, contributing to reduced exercise tolerance. However, skeletal muscle mitochondria appeared resistant to the beneficial effects of exercise training, suggesting that other physiological systems, at least in part, drive the improvements in exercise capacity following exercise training in MS

Altered muscle oxidative phenotype impairs exercise tolerance but does not improve after exercise training in multiple sclerosis

Background: Patients with multiple sclerosis (MS) experience reduced exercise tolerance that substantially reduces quality of life. The mechanisms underpinning exercise intolerance in MS are not fully clear. This study aimed to determine the contributions of the cardiopulmonary system and peripheral muscle in MS-induced exercise intolerance before and after exercise training. Methods: Twenty-three patients with MS (13 women) and 20 age-matched and sex-matched healthy controls (13 women) performed a cardiopulmonary exercise test. Muscle fibre type composition, size, succinate dehydrogenase (SDH) activity, capillarity, and gene expression and proteins related to mitochondrial density were determined in vastus lateralis muscle biopsies. Nine MS patients (five women) were re-examined following a 12 week exercise training programme consisting of high-intensity cycling interval and resistance training. Results: Patients with MS had lower maximal oxygen uptake compared with healthy controls (V̇O 2peak, 25.0 ± 8.5 vs. 35.7 ± 6.4 mL/kg/min, P  0.05). V̇O 2peak increased by 23% following exercise training in MS (P  0.05). Conclusions: Skeletal muscle oxidative phenotype (mitochondrial complex I and II content, SDH activity) is lower in patients with MS, contributing to reduced exercise tolerance. However, skeletal muscle mitochondria appeared resistant to the beneficial effects of exercise training, suggesting that other physiological systems, at least in part, drive the improvements in exercise capacity following exercise training in MS

Chronotropic incompetence is more frequent in obese adolescents and relates to systemic inflammation and exercise intolerance

Background: Adults with obesity may display disturbed cardiac chronotropic responses during cardiopulmonary exercise testing, which relates to poor cardiometabolic health and an increased risk for adverse cardiovascular events. It is unknown whether cardiac chronotropic incompetence (CI) during maximal exercise is already present in obese adolescents and, if so, how that relates to cardiometabolic health. Methods: Sixty-nine obese adolescents (body mass index standard deviation score = 2.23 ± 0.32, age = 14.1 ± 1.2 years; mean ± SD) and 29 lean adolescents (body mass index standard deviation score = –0.16 ± 0.84, age = 14.0 ± 1.5 years) performed a maximal cardiopulmonary exercise testing from which indicators for peak performance were determined. The resting heart rate and peak heart rate were used to calculate the maximal chronotropic response index. Biochemistry (lipid profile, glycemic control, inflammation, and leptin) was studied in fasted blood samples and during an oral glucose tolerance test within obese adolescents. Regression analyses were applied to examine associations between the presence of CI and blood or exercise capacity parameters, respectively, within obese adolescents. Results: CI was prevalent in 32 out of 69 obese adolescents (46%) and 3 out of 29 lean adolescents (10%). C-reactive protein was significantly higher in obese adolescents with CI compared to obese adolescents without CI (p = 0.012). Furthermore, peak oxygen uptake and peak cycling power output were significantly reduced (p < 0.05) in obese adolescents with CI vs. obese adolescents without CI. The chronotropic index was independently related to blood total cholesterol (standardized coefficient β = –0.332; p = 0.012) and C-reactive protein concentration (standardized coefficient β = –0.269; p = 0.039). Conclusion: CI is more common in the current cohort of obese adolescents, and is related to systemic inflammation and exercise intolerance

Exercise capacity is related to attenuated responses in oxygen extraction and left ventricular longitudinal strain in asymptomatic type 2 diabetes patients

Aims: Type 2 diabetes mellitus (T2DM) is associated with reduced exercise capacity and cardiovascular diseases, both increasing morbidity and risk for premature death. As exercise intolerance often relates to cardiac dysfunction, it remains to be elucidated to what extent such an interplay occurs in T2DM patients without overt cardiovascular diseases. Design: Cross-sectional study, NCT03299790. Methods and results: Fifty-three T2DM patients underwent exercise echocardiography (semi-supine bicycle) with combined ergospirometry. Cardiac output (CO), left ventricular longitudinal strain (LS), oxygen uptake (O2), and oxygen (O2) extraction were assessed simultaneously at rest, low-intensity exercise, and high-intensity exercise. Glycaemic control and lipid profile were assessed in the fasted state. Participants were assigned according to their exercise capacity being adequate or impaired (EXadequate: O2peak &lt;80% and EXimpaired: O2peak ≥80% of predicted O2peak) to compare O2 extraction, CO, and LS at all stages. Thirty-eight participants (EXimpaired: n = 20 and EXadequate: n = 18) were included in the analyses. Groups were similar regarding HbA1c, age, and sex (P &gt; 0.05). At rest, CO was similar in the EXimpaired group vs. EXadequate group (5.1 ± 1 L/min vs. 4.6 ± 1.4 L/min, P &gt; 0.05) and increased equally during exercise. EXimpaired patients displayed a 30.7% smaller increase in O2 extraction during exercise compared to the EXadequate group (P = 0.016) which resulted in a lower O2 extraction at high-intensity exercise (12.5 ± 2.8 mL/dL vs. 15.3 ± 3.9 mL/dL, P = 0.012). Left ventricular longitudinal strain was similar at rest but increased significantly less in the EXimpaired vs. EXadequate patients (1.9 ± 2.5% vs. 5.9 ± 4.1%, P = 0.004). Conclusions: In asymptomatic T2DM patients, an impaired exercise capacity is associated with an impaired response in oxygen extraction and myocardial deformation (LS).</p