Deterioration of Limb Muscle Function during Acute Exacerbation of Chronic Obstructive Pulmonary Disease

Smoking history: relationships with inflammatory markers, metabolic markers, body composition, muscle strength, and cardiopulmonary capacity in current smokers

OBJECTIVE

To determine the relationships that smoking history has with inflammatory markers, metabolic markers, body composition, muscle strength, and cardiopulmonary capacity in current smokers.

METHODS

This was a cross-sectional study involving 65 smokers (age range: 18-60 years). On three non-consecutive days, each participant was evaluated in terms of smoking history, pre-existing comorbidities, lung function (by spirometry), peripheral muscle strength (by dynamometry), body composition (by bioelectrical impedance analysis), levels of metabolic/inflammatory markers, and maximum cardiopulmonary capacity (by treadmill exercise test). We evaluated the relationships that smoking history has with inflammatory markers, metabolic markers, body composition, muscle strength, and cardiopulmonary capacity, using logarithmic transformation of the data and calculating Pearson's correlation coefficient and for partial correlations adjusted for age, gender, body mass index (BMI), and comorbidities. To identify the influence of smoking history on pre-existing comorbidities, we used a logistic regression model adjusted for age, BMI, and duration of smoking.

RESULTS

Smoking history correlated significantly, albeit weakly, with triglyceride level (r = 0.317; p = 0.005), monocyte count (r = 0.308; p = 0.013), and waist circumference (r = 0.299; p = 0.017). However, those correlations did not retain their significance in the adjusted analysis. In the logistic regression model, smoking more than 20 cigarettes/day correlated significantly with the presence of metabolic diseases (OR = 0.31; 95% CI: 1.009-1.701; p = 0.043).

CONCLUSIONS

In this sample of smokers, smoking history correlated positively with the triglyceride level, the monocyte count, and waist circumference. The prevalence of metabolic disease was highest in those who smoked more than 20 cigarettes/day.

AMP-Activated Protein Kinase (AMPK) at the Crossroads Between CO2 Retention and Skeletal Muscle Dysfunction in Chronic Obstructive Pulmonary Disease (COPD)

Skeletal muscle dysfunction is a major comorbidity in chronic obstructive pulmonary disease (COPD) and other pulmonary conditions. Chronic CO2 retention, or hypercapnia, also occur in some of these patients. Both muscle dysfunction and hypercapnia associate with higher mortality in these populations. Over the last years, we have established a mechanistic link between hypercapnia and skeletal muscle dysfunction, which is regulated by AMPK and causes depressed anabolism via reduced ribosomal biogenesis and accelerated catabolism via proteasomal degradation. In this review, we discuss the main findings linking AMPK with hypercapnic pulmonary disease both in the lungs and skeletal muscles, and also outline potential avenues for future research in the area based on knowledge gaps and opportunities to expand mechanistic research with translational implications.

Reactive Jumps Preserve Skeletal Muscle Structure, Phenotype, and Myofiber Oxidative Capacity in Bed Rest

Identification of countermeasures able to prevent disuse-induced muscle wasting is crucial to increase performance of crew members during space flight as well as ameliorate patient’s clinical outcome after long immobilization periods. We report on the outcome of short but high-impact reactive jumps (JUMP) as countermeasure during 60 days of 6° head-down tilt (HDT) bed rest on myofiber size, type composition, capillarization, and oxidative capacity in tissue biopsies (pre/post/recovery) from the knee extensor vastus lateralis (VL) and deep calf soleus (SOL) muscle of 22 healthy male participants (Reactive jumps in a sledge, RSL-study 2015–2016, DLR:envihab, Cologne). Bed rest induced a slow-to-fast myofiber shift (type I –>II) with an increased prevalence of hybrid fibers in SOL after bed rest without jumps (control, CTRL, p = 0.016). In SOL, JUMP countermeasure in bed rest prevented both fast and slow myofiber cross-sectional area (CSA) decrements (p = 0.005) in CTRL group. In VL, bed rest only induced capillary rarefaction, as reflected by the decrease in local capillary-to-fiber ratio (LCFR) for both type II (pre vs. post/R + 10, p = 0.028/0.028) and type I myofibers (pre vs. R + 10, p = 0.012), which was not seen in the JUMP group. VO_2maxFiber (pL × mm^–1 × min^–1) calculated from succinate dehydrogenase (SDH)-stained cryosections (OD_{660 nm}) showed no significant differences between groups. High-impact jump training in bed rest did not prevent disuse-induced myofiber atrophy in VL, mitigated phenotype transition (type I – >II) in SOL, and attenuated capillary rarefaction in the prime knee extensor VL however with little impact on oxidative capacity changes.

Handgrip strength and its relation to isokinetic dynamometry in COPD

Abstract Introduction: Muscle dysfunction is one of the major changes found in chronic obstructive pulmonary disease (COPD) and associated with loss of functionality, morbidity and mortality. Objective: correlate two strength assessment methods: manual dynamometry for handgrip strength and isokinetic dynamometry for quadriceps strength in patients with COPD, and assess the body mass index, airflow obstruction, dyspnea, and exercise capacity (BODE), quality of life and muscle strength. Method: twenty-five patients with moderate to very severe COPD were evaluated by pulmonary function parameters, anthropometric variables, functional capacity, via the six-minute walk test, dyspnea, applying the modified Medical Research Council (mMRC) scale, BODE, quality of life, using the Saint George's Respiratory Questionnaire (SGRQ), handgrip strength with manual dynamometer and quadriceps force using an isokinetic dynamometer. Muscle strength was assessed with a manual portable dynamometer and isokinetic dynamometer. For statistical analysis, ANOVA with Bonferroni’s post-test, the chi-squared test and Pearson's correlation coefficient were used. Results: There was a strong correlation between the strength measurements and the two instruments (torque and quadriceps extension power with right handgrip strength: r = 0.74; p <0.001). The patients classified as very severe exhibited worse performance in the strength tests when compared to the moderate group, albeit with no statistically significant difference. Conclusion: In muscle strength measurements, a strong correlation was detected between the isokinetic dynamometer for quadriceps and the manual dynamometer for handgrip strength. These findings indicate that, in clinical practice, the manual dynamometer for handgrip strength could be used to assess peripheral muscle strength in patients with COPD.

Contemporary approaches in the use of extracorporeal membrane oxygenation to support patients waiting for lung transplantation

The introduction of the lung allocation score in 2005 prioritized patients with decreased transplant-free survival as the recipients of donor organs and effectively increased the number of critically-ill patients with end-stage lung disease waiting for transplantation. This change presented transplant programs with the challenge of how to both extend the lives of critically-ill, end-stage lung disease patients waiting for donor organs and maintain patient vitality to survival through the rigors of surgery and post-transplant recovery. Motivated by the dismal outcomes of patients maintained on mechanical ventilation pre-transplant, transplant centers increasingly deploy extracorporeal membrane oxygenation (ECMO) as a means of supporting patients with advanced disease as a bridge to successful lung transplantation. ECMO is an extracorporeal gas exchange device providing delivery of oxygen and removal of carbon dioxide from blood passed through the circuit. The specific cannulation strategy determines whether ECMO provides primarily respiratory or circulatory support. The cannulation approach is tailored to the specific physiological manifestations of the pre-lung transplant candidate's disease process. For patients with profound hypoxic respiratory failure, a cannulation strategy that captures a large fraction of the venous return is required to maintain adequate support whereas lower circuit flows are sufficient for patients with predominantly hypercapnic respiratory failure. Improving outcomes and increasing experience with ECMO is motivating transplant centers to initiate support before patients require mechanical ventilation. Awake cannulation is increasingly common and is used to avoid the complications associated with intubation in advanced lung failure. Determining criteria for initiation of support and identifying the optimal approach to support patients with right heart failure in need of circulatory support are avenues of active investigation. Use of ECMO and other forms of extracorporeal support are rapidly becoming a mainstay in the care of the pre-lung transplant patient with advanced disease.

Sarcopenia in COPD: a systematic review and meta-analysis

COPD is associated with a progressive loss of muscle mass and function. However, there is an unmet need to define and standardise methods to estimate the prevalence of sarcopenia in COPD patients.

We performed a systematic review and meta-analysis of the prevalence of this extrapulmonary manifestation in COPD patients. We searched Embase, Medline (Ovid), CINAHL (EBSCO), Web of Science, Scopus and Google Scholar for studies published up to January 17, 2019, assessing sarcopenia in COPD patients based on low muscle mass and decreased muscle function. Interventional studies, in vitro experiments, protocols or reviews and meta-analyses were excluded. We estimated heterogeneity (I²) and assessed significance (Q) using a Chi-squared test for estimates obtained from random-effects models.

4465 articles were initially identified. After removing the duplicates and applying the selection criteria, we reviewed 62 full-text articles. Finally, 10 articles (n=2565 COPD patients) were included in this systematic review and meta-analyses. Overall, the prevalence of sarcopenia in patients with COPD was 21.6% (95% CI 14.6–30.9%, I²=94%), ranging from 8% in population-based to 21% in clinic-based studies, and 63% in COPD patients residing in nursing homes.

Sarcopenia is frequently observed in COPD patients, with varying prevalence across population settings. Sarcopenia in COPD should be assessed using standardised tests and cut-off points from sarcopenia consensus criteria for clinical practice and international comparisons.

We confirmed a high prevalence of sarcopenia in COPD patients, with varying prevalence across population settings. We recommend adhering to the sarcopenia consensus criteria to systematically evaluate the muscle health of COPD patients.http://bit.ly/2KA6weh

Skeletal Muscle Dysfunction in Chronic Obstructive Pulmonary Disease. What We Know and Can Do for Our Patients

Skeletal muscle dysfunction occurs in patients with chronic obstructive pulmonary disease (COPD) and affects both ventilatory and nonventilatory muscle groups. It represents a very important comorbidity that is associated with poor quality of life and reduced survival. It results from a complex combination of functional, metabolic, and anatomical alterations leading to suboptimal muscle work. Muscle atrophy, altered fiber type and metabolism, and chest wall remodeling, in the case of the respiratory muscles, are relevant etiological contributors to this process. Muscle dysfunction worsens during COPD exacerbations, rendering patients progressively less able to perform activities of daily living, and it is also associated with poor outcomes. Muscle recovery measures consisting of a combination of pulmonary rehabilitation, optimized nutrition, and other strategies are associated with better prognosis when administered in stable patients as well as after exacerbations. A deeper understanding of this process' pathophysiology and clinical relevance will facilitate the use of measures to alleviate its effects and potentially improve patients' outcomes. In this review, a general overview of skeletal muscle dysfunction in COPD is offered to highlight its relevance and magnitude to expert practitioners and scientists as well as to the average clinician dealing with patients with chronic respiratory diseases.

Impact of preoperative exercise therapy on surgical outcomes in lung cancer patients with or without COPD: a systematic review and meta-analysis

Objectives

This meta-analysis aimed to demonstrate the impact of preoperative exercise therapy on surgical outcomes in patients with lung cancer and COPD. Pulmonary function and muscle capacity were investigated to explore their potential links with outcome improvements after exercise.

Methods

Articles were searched from PubMed, Embase, and the Cochrane Library with criteria of lung cancer patients with or without COPD, undergoing resection, and receiving preoperative exercise training. Key outcomes were analyzed using meta-analysis.

Results

Seven studies containing 404 participants were included. Patients receiving preoperative exercise training had a lower incidence of postoperative pulmonary complications (PPCs; OR 0.44, 95% CI 0.27-0.71) and shorter length of hospital stay (standardized mean difference -4.23 days, 95% CI -6.14 to -2.32 days). Exceptionally, pneumonia incidence remained unchanged. Patients with COPD could not obviously benefit from exercise training to reduce PPCs (OR 0.44, 95% CI 0.18-1.08), but still might achieve faster recovery. No significant difference in pulmonary function was observed between the two groups. However, 6MWD and VO₂ peak were significantly improved after exercise training.

Conclusion

Preoperative exercise training may reduce PPCs for lung cancer patients. However, for patients with COPD undergoing lung cancer resection, the role of exercise is uncertain, due to limited data, which calls for more prospective trials on this topic. Rehabilitation exercise strengthens muscle capacity, but does not improve impaired pulmonary function, which emphasizes the possible mechanism of the protocol design.

Is the 6-minute pegboard and ring test valid to evaluate upper limb function in hospitalized patients with acute exacerbation of COPD?

Background

The 6-minute pegboard and ring test (6-PBRT) is a useful test for assessing the functional capacity of upper limbs in patients with stable COPD. Although 6-PBRT has been validated in stable patients, the possibility of a high floor effect could compromise the validity of the test in the hospital setting. The aim of this study was to verify the convergent validity of 6-PBRT in hospitalized patients with acute exacerbation of COPD (AECOPD).

Methods

A cross-sectional study was conducted in a tertiary hospital. Patients who were hospitalized due to AECOPD and healthy elderly participants, voluntarily recruited from the community, were considered for inclusion. All participants underwent a 6-PBRT. Isokinetic evaluation to measure the strength and endurance of elbow flexors and extensors, handgrip strength (HGS), spirometry testing, the modified Pulmonary Functional Status Dyspnea Questionnaire (PFSDQ-M), the COPD assessment test (CAT), and symptoms of dyspnea and fatigue were all measured as comparisons for convergent validity. Good convergent validity was considered if >75% of these hypotheses could be confirmed (correlation coefficient>0.50).

Results

A total of 17 patients with AECOPD (70.9±5.1 years and forced expiratory volume in 1 second [FEV₁] of 41.8%±17.9% of predicted) and 11 healthy elderly subjects were included. The HGS showed a significant strong correlation with 6-PBRT performance (r=0.70; p=0.002). The performance in 6-PBRT presented a significant moderate correlation with elbow flexor torque peak (r=0.52; p=0.03) and elbow extensor torque peak (r=0.61; p=0.01). The total muscular work of the 15 isokinetic contractions of the elbow flexor and extensor muscles showed a significant moderate correlation with the performance in 6-PBRT (r=0.59; p=0.01 and r=0.57; p=0.02, respectively). Concerning the endurance of elbow flexors and extensors, there was a significant moderate correlation with 6-PBRT performance (r=−0.50; p=0.04 and r=−0.51; p=0.03, respectively). In relation to the upper-extremity physical activities of daily living (ADLs) assessed by means of PFSDQ-M, there was a significant moderate correlation of 6-PBRT with three domains: influence of dyspnea on ADLs (r=−0.66; p<0.001), influence of fatigue on ADLs (r=−0.60; p=0.01), and change in ADLs in relation to the period before the disease onset (r=−0.51; p=0.03). The CAT was also correlated with 6-PBRT (r=−0.51; p=0.03). Finally, the performance in 6-PBRT showed a significant moderate correlation with the increase in dyspnea (r=−0.63; p=0.01) and a strong correlation with the increase in fatigue of upper limbs (r=−0.76; p<0.001) in patients with AECOPD. Convergent validity was considered adequate, since 81% from 16 predefined hypotheses were confirmed. There was no correlation between 6-PBRT and patients’ height. The performance in 6-PBRT was worse in patients with AECOPD compared to healthy elderly individuals (248.7±63.0 vs 361.6±49.9 number of moved rings; p<0.001).

Conclusion

The 6-PBRT is valid for the evaluation of functional capacity of upper limbs in hospitalized patients with AECOPD.

Pulmonary rehabilitation in patients with an acute exacerbation of chronic obstructive pulmonary disease

Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) are one of the most common causes of emergency hospital admission and place great burden upon healthcare systems. Furthermore, AECOPD represent an important life event for patients, and are associated with significant reductions in physical activity, skeletal muscle function, exercise tolerance and health-related quality of life. Pulmonary rehabilitation, an intervention comprising supervised exercise-training and education, may counteract these negative consequences and target modifiable risk factors for hospital readmission. A recent Cochrane systematic review included 20 randomized controlled trials comparing pulmonary rehabilitation after exacerbation of COPD versus conventional care. Overall, the evidence supports moderate to large effects on health-related quality of life and exercise capacity. However, there is substantial heterogeneity across studies, and more recent studies have been more equivocal, including around hospital readmissions, particularly when rehabilitation is started in the inpatient setting. In this narrative review, we examine the rationale for pulmonary rehabilitation following AECOPD with a particular focus on skeletal muscle function, review the current evidence for pulmonary rehabilitation in the AECOPD setting, and identify areas that require future research, including the structure and nature of the intervention, improving uptake and adherence, and the role of alternative rehabilitation strategies for patients with AECOPD.

Magnetic Stimulation Therapy in Patients with COPD: A Systematic Review

Magnetotherapy (MT) is a therapeutic treatment based on the use of magnetic fields (MF) that can have an anti-inflammatory and analgesic effect. MT represents a possible treatment or an ancillary therapeutic intervention for a wide range of diseases and it is often used in the field of physiotherapeutic practices. A crucial point in the treatment of chronic obstructive pulmonary disease (COPD) patients, to counteract muscular depletion and respiratory symptoms, is represented by physiotherapy. Nevertheless, the knowledge about the application of MF as a therapeutic option in COPD patients is very limited. The purpose of the present study was to define what is currently known about the use of MF in patients with COPD. A systematic review of the literature was conducted during the month of October 2017, searching three main databases. Only those citations providing detailed informations about the use of MF to treat COPD symptoms either during an acute or a chronic phase of the disease, were selected. Following the selection process three articles were included in the final analysis. The present review focused on a total of thirty-six patients with COPD, and on the effects of the application of MF. In the majority of cases, the treatment sessions with MF were carried-out in an outpatient setting, and they differed with regard to the duration; frequency of application; dosage; intensity of the applied MF. Basing on the available informations, it seems that MF is a feasible, well tolerated, safe therapeutic option, for the treatment of motor-related COPD symptoms.