Ectopic fat accumulation in patients with COPD:an ECLIPSE substudy

Background: Obesity is increasingly associated with COPD, but little is known about the prevalence of ectopic fat accumulation in COPD and whether this can possibly be associated with poor clinical outcomes and comorbidities. The Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints (ECLIPSE) substudy tested the hypothesis that COPD is associated with increased ectopic fat accumulation and that this would be associated with COPD-related outcomes and comorbidities. Methods: Computed tomography (CT) images of the thorax obtained in ECLIPSE were used to quantify ectopic fat accumulation at L2–L3 (eg, cross-sectional area [CSA] of visceral adipose tissue [VAT] and muscle tissue [MT] attenuation, a reflection of muscle fat infiltration) and CSA of MT. A dose–response relationship between CSA of VAT, MT attenuation and CSA of MT and COPD-related outcomes (6-minute walking distance [6MWD], exacerbation rate, quality of life, and forced expiratory volume in 1 second [FEV1] decline) was addressed with the Cochran–Armitage trend test. Regression models were used to investigate possible relationships between CT body composition indices and comorbidities. Results: From the entire ECLIPSE cohort, we identified 585 subjects with valid CT images at L2–L3 to assess body composition. CSA of VAT was increased (P<0.0001) and MT attenuation was reduced (indicating more muscle fat accumulation) in patients with COPD (P<0.002). Progressively increasing CSA of VAT was not associated with adverse clinical outcomes. The probability of exhibiting low 6MWD and accelerated FEV1 decline increased with progressively decreasing MT attenuation and CSA of MT. In COPD, the probability of having diabetes (P=0.024) and gastroesophageal reflux (P=0.0048) at baseline increased in parallel with VAT accumulation, while the predicted MT attenuation increased the probability of cardiovascular comorbidities (P=0.042). Body composition parameters did not correlate with coronary artery scores or with survival. Conclusion: Ectopic fat accumulation is increased in COPD, and this was associated with relevant clinical outcomes and comorbidities

Physiological Correlates of Endurance Time Variability during Constant-Workrate Cycling Exercise in Patients with COPD

RATIONALE: The endurance time (T(end)) during constant-workrate cycling exercise (CET) is highly variable in COPD. We investigated pulmonary and physiological variables that may contribute to these variations in T(end). METHODS: Ninety-two patients with COPD completed a CET performed at 80% of peak workrate capacity (W(peak)). Patients were divided into tertiles of T(end) [Group 1: <4 min; Group 2: 4-6 min; Group 3: >6 min]. Disease severity (FEV(1)), aerobic fitness (W(peak), peak oxygen consumption [VO2(peak)], ventilatory threshold [VO2(VT)]), quadriceps strength (MVC), symptom scores at the end of CET and exercise intensity during CET (heart rate at the end of CET to heart rate at peak incremental exercise ratio [HR(CET)/HR(peak)]) were analyzed as potential variables influencing T(end). RESULTS: W(peak), VO2(peak), VO2(VT), MVC, leg fatigue at end of CET, and HR(CET)/HR(peak) were lower in group 1 than in group 2 or 3 (p≤0.05). VO2(VT) and leg fatigue at end of CET independently predicted T(end) in multiple regression analysis (r = 0.50, p = 0.001). CONCLUSION: T(end) was independently related to the aerobic fitness and to tolerance to leg fatigue at the end of exercise. A large fraction of the variability in T(end) was not explained by the physiological parameters assessed in the present study. Individualization of exercise intensity during CET should help in reducing variations in T(end) among patients with COPD

IMPACT DE LA FAIBLESSE MUSCULAIRE SUR LA TOLERANCE A L'EFFORT ET LA QUALITE DE VIE DES PATIENTS ATTEINTS DE BPCO : BENEFICE DU REENTRAINEMENT A L'EFFORT

Chronic obstructive pulmonary disease (COPD) is a growing health problem both in primary and secondary care. Among systemic abnormalities, peripheral muscle dysfunction is now recognized as a main factor of physiopathology in COPD and peripheral muscle weakness is of particular interest since it has been associated with high utilization of health care resources and poor prognosis in COPD. Thus, the place of specific strength training in the rehabilitation of COPD patients is actually discussed. Although the benefit of endurance training on muscular metabolism during exercise has been proven, a poorer impact on peripheral muscle strength was reported. Furthermore, such training is not always easy to perform in severe COPD patients with early dynamic hyperinflation during muscular exercise. Thus, our research aimed to assess the role of peripheral muscle weakness in exercise tolerance and quality of life in very severe COPD patients in order to better individualize exercise training. We first confirmed that magnetic stimulation of femoral nerve is a valid and reproducible method and that it's sensitive enough to detect little changes in muscle strength after training. Using this tool, we showed that peripheral muscle weakness is independently related to exercise intolerance in very severe COPD patients. We showed this muscle weakness was partly related to a deficit in central activation during leg extension. Any intervention leading to an increase in physical activity level improved muscle strength decreasing in turn dyspnea and leg discomfort during exercise. In this way, electrostimulation of the quadriceps muscle is an alternative strategy which appeared to be particularly well adapted for very severe COPD patients, unable to perform cycle exercise. Taken together, our results suggested mechanisms such as central adaptation could be involved in peripheral muscle strength gains after training in very severe COPD patients. Furthermore, an increase in muscle strength would be transferred into a reduction in dyspnea during daily tasks leading to better tolerance and an improved quality of life in patients after lung transplantation, in whom the respiratory function was almost normalized. In conclusion, resistive training seems to be particularly relevant in rehabilitation of COPD patients and peripheral muscle weakness should be considered in the same way as pulmonary severity to individualize exercise training program in COPD patients.La broncho-pneumopathie chronique obstructive (BPCO) est un problème de santé publique majeur qui doit être aujourd'hui considérée comme une maladie générale. Parmi les atteintes systémiques, la dysfonction musculaire est un élément central de la physiopathologie de la BPCO dominant l'évolution de la maladie. En effet, la faiblesse musculaire périphérique est associée à une survie moindre, à des coûts de santé élevés et, est un facteur de mauvais pronostic indépendant de l'atteinte respiratoire. La place de l'entraînement en force du muscle périphérique dans la réhabilitation des patients BPCO est au cœur de nombreuses études scientifiques récentes. En effet, bien que l'entraînement en endurance ait fait la preuve de son efficacité sur le métabolisme musculaire périphérique et la capacité à l'effort des patients modérés à sévères son impact sur la force musculaire périphérique est plus modéré. D'autre part, son application est difficile chez les patients très sévères qui présentent une intolérance à l'effort marquée. Notre travail de recherche s'est inscrit dans la compréhension du rôle de la faiblesse musculaire dans la tolérance à l'effort et la qualité de vie des patients BPCO sévères et très déconditionnés avec pour cible un début d'individualisation des programmes de réentraînement à l'effort chez ces patients. Après avoir évalué et confirmé la fiabilité et la sensibilité de l'évaluation de la force musculaire non coopérante du quadriceps par stimulation magnétique du nerf fémoral, nous avons montré qu'il existe une faiblesse musculaire marquée chez certains patients BPCO très sévères et hypoxémiques et qu'elle joue un rôle indépendant dans leur intolérance à l'effort. La démonstration que cette faiblesse musculaire est en particulier liée à un déficit d'activation centrale constitue un résultat original de nos travaux. Chez les patients sévères, nous avons montré que toute intervention visant à ré-augmenter le niveau d'activité physique, conduit à une amélioration de la force musculaire qui, à son tour, diminue les symptômes à l'effort. Parmi les stratégies d'amélioration de la force musculaire périphérique utilisées dans nos travaux, l'électrostimulation apparaît comme un outil particulièrement adapté chez les patients BPCO les plus sévères inaptes à la pratique du cycloergomètre. Nos résultats suggèrent que des adaptations centrales nerveuses sont impliquées dans l'amélioration de la force musculaire faisant suite au réentraînement. D'autre part, l'amélioration de la force musculaire induite par le réentraînement pourrait induire une réduction des symptômes respiratoires au cours des activités quotidiennes chez des patients transplantés pulmonaires qui ont retrouvé une capacité respiratoire quasi normale, favorisant leur tolérance à ce type d'effort et ainsi leur qualité de vie. Ainsi, nous pensons que le réentraînement spécifique de la force musculaire a aujourd'hui sa place dans la réhabilitation à l'effort des patients très sévèrement déconditionnés et que la sévérité de la faiblesse musculaire devrait être considérée sur un même plan que la sévérité de l'atteinte pulmonaire lors de l'adaptation des programmes de réentraînement à l'effort chez les patients BPCO

Impact de la faiblesse musculaire sur la tolérance à l'effort et la qualité de vie des patients atteints de BPCO (bénéfice du réentraînement à l'effort)

La broncho-pneumopathie chronique obstructive (BPCO) est un problème de santé publique majeur qui doit être aujourd'hui considérée comme une maladie générale. Parmi les atteintes systémiques, la dysfonction musculaire est un élément central de la physiopathologie de la BPCO dominant l'évolution de la maladie. En effet, la faiblesse musculaire périphérique est associée à des coûts de santé élevés et est un facteur de mauvais pronostic indépendant de l'atteinte respiratoire. Or, l'impact du réentraînement en endurance sur la force musculaire reste modéré et son application est difficile chez les patients très sévères qui présentent une intolérance à l'effort marquée. Parallèlement, la place de l'entraînement en force du muscle périphérique dans la réhabilitation des patients BPCO est au cœur de nombreuses études scientifiques récentes. Notre travail recherche s'est inscrit dans la compréhension du rôle de la faiblesse musculaire dans la tolérance à l'effort et la qualité de vie des patients BPCO sévères et très déconditionnés avec pour cible un début d'individualisation des programmes de réentraînement à l'effort chez ces patients. Nos résultats montrent que le réentraînement spécifique de la force musculaire a aujourd'hui sa place dans la réhabilitation à l'effort des patients très sévèrement déconditionnés, pouvant notamment consister en l'utilisation de techniques de musculation non intentionnelle telle que l'électrostimulation neuromusculaire. Enfin, la sévérité de la faiblesse musculaire devrait être considérée sur un même plan que la sévérité de l'atteinte pulmonaire lors de l'adaptation des programmes de réentraînement à l'effort chez les Datients BPCOGRENOBLE1-BU Sciences (384212103) / SudocSudocFranceF

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Journal of Cardiopulmonary Rehabilitation and Prevention Cardiac, autonomic and cardiometabolic impact of exercise training in spinal cord injury: A qualitative review

International audienceStudies showed similar exercise effects in both groups (n = 31 in low CV risk factors vs n = 15 in high CV risk factors). The evidence does not support any effect of exercise training on autonomic function but does support an increased peripheral blood flow, improved left ventricular mass, higher peak cardiac output, greater lean body mass, better antioxidant capacity, and improved endothelial function. In addition, some evidence suggests that it can result in lower blood lipids, systemic inflammation (interleukin-6, tumor necrosis factor α, and C-reactive protein), and arterial stiffness. Training intensity, volume, and frequency were key factors determining CV gains. Future studies with larger sample sizes, well-matched groups of subjects, and randomized controlled designs will be needed to determine whether high-intensity hybrid forms of training result in greater CV gains

Serotonin 1A Receptor Pharmacotherapy and Neuroplasticity in Spinal Cord Injury

International audienceSpinal cord injury is associated with damage in descending and ascending pathways between brainstem/cortex and spinal neurons, leading to loss in sensory-motor functions. This leads not only to locomotor reduction but also to important respiratory impairments, both reducing cardiorespiratory engagement, and increasing cardiovascular risk and mortality. Moreover, individuals with high-level injuries suffer from sleep-disordered breathing in a greater proportion than the general population. Although no current treatments exist to restore motor function in spinal cord injury (SCI), serotoninergic (5-HT) 1A receptor agonists appear as pharmacologic neuromodulators that could be important players in inducing functional improvements by increasing the activation of spared motoneurons. Indeed, single therapies of serotoninergic 1A (5-HT1A) agonists allow for acute and temporary recovery of locomotor function. Moreover, the 5-HT1A agonist could be even more promising when combined with other pharmacotherapies, exercise training, and/or spinal stimulation, rather than administered alone. In this review, we discuss previous and emerging evidence showing the value of the 5HT1A receptor agonist therapies for motor and respiratory limitations in SCI. Moreover, we provide mechanistic hypotheses and clinical impact for the potential benefit of 5-HT1A agonist pharmacology in inducing neuroplasticity and improving locomotor and respiratory functions in SCI

Improvement in Quadriceps Muscle Strength and Fucntional Capacities after a 3-month home-based Endurance Training in Lung Transplant Recipients

Background: Peripheral muscle dysfunction and reduced exercise capacity are well recognized in lung transplant recipients (LTR) in spite of improved lung function. However, the effect of exercise training in this specific population is still poor studied. We investigated the benefits of training on muscle function and cardio-ventilatory response during exercise in LTR. Methods: Twelve patients after lung transplantation (FEV1: 74 &#177; 24 % of predicted value) and 12 healthy subjects (C) were studied before and after a 3-month home-based endurance training. Quadriceps strength and fatigability were assessed by maximal twitch tension (TwQ) using magnetic stimulation of the femoral nerve and fiber diameters were obtained after biopsy of the vastus lateralis. Cardio-ventilatory responses were measured during both maximal and constant workload (W) cycle exercise and quality of life was assessed by the Chronic Respiratory Questionnaire. Results: At baseline, LTR had lower percentage of type I fibers, TwQ, Wmax, VO2max, VEmax and endurance time than C (< 50% of C each). After training, significant improvement in TwQ (+44 &#177; 26 N), Wmax (+13 &#177; 19 W), endurance time (+11.5 &#177; 11.1 min) and dyspnea score (CRQdyspnea: +3.1 &#177; 4.4 points) were observed in LTR (p < 0.05). Furthermore, VE was reduced at submaximal (VE at ventilatory threshold: -4.5 &#177; 6.8 L/min) and constant (65% Wmax) exercise (-6.4 &#177; 5.2 L/min) (P < 0.05). Decrease in exercise-induced fatigability correlated with decrease in VE at initial maximal workload in LTR (r = 0.72, P = 0.06) and in LTR + C (r = 0.56, P = 0.02) and increase in TwQ correlated to increase in CRQdyspnea in LTR (r = 0.74, P = 0.04). Conclusion: Gains in exercise capacity and in quadriceps strength were observed after endurance training in LTR. The latter may have been involved in improving exercise ventilatory response and dyspnea, supporting the benefit of peripheral muscle strength improvement in exercise tolerance in LTR and even the larger field of chronic respiratory diseases