Sarcopenia in COPD: prevalence, clinical correlates and response to pulmonary rehabilitation

The role of TGF-β signaling in muscle atrophy, sarcopenia and cancer cachexia

Skeletal muscle, comprising a significant proportion (40 to 50 percent) of total body weight in humans, plays a critical role in maintaining normal physiological conditions. Muscle atrophy occurs when the rate of protein degradation exceeds protein synthesis. Sarcopenia refers to age-related muscle atrophy, while cachexia represents a more complex form of muscle wasting associated with various diseases such as cancer, heart failure, and AIDS. Recent research has highlighted the involvement of signaling pathways, including IGF1-Akt-mTOR, MuRF1-MAFbx, and FOXO, in regulating the delicate balance between muscle protein synthesis and breakdown. Myostatin, a member of the TGF-β superfamily, negatively regulates muscle growth and promotes muscle atrophy by activating Smad2 and Smad3. It also interacts with other signaling pathways in cachexia and sarcopenia. Inhibition of myostatin has emerged as a promising therapeutic approach for sarcopenia and cachexia. Additionally, other TGF-β family members, such as TGF-β1, activin A, and GDF11, have been implicated in the regulation of skeletal muscle mass. Furthermore, myostatin cooperates with these family members to impair muscle differentiation and contribute to muscle loss. This review provides an overview of the significance of myostatin and other TGF-β signaling pathway members in muscular dystrophy, sarcopenia, and cachexia. It also discusses potential novel therapeutic strategies targeting myostatin and TGF-β signaling for the treatment of muscle atrophy.

A Japanese herbal medicine (kampo), hochuekkito (TJ-41), has anti-inflammatory effects on the chronic obstructive pulmonary disease mouse model

Chronic obstructive pulmonary disease (COPD) is a progressive disease that is characterized by chronic airway inflammation. A Japanese herbal medicine, hochuekkito (TJ-41), is prominently used for chronic inflammatory diseases in Japan. This study aimed to analyze the anti-inflammatory effect of TJ-41 in vivo and its underlying mechanisms. We created a COPD mouse model using intratracheal administration of porcine pancreatic elastase and lipopolysaccharide (LPS) and analyzed them with and without TJ-41 administration. A TJ-41-containing diet reduced inflammatory cell infiltration of the lungs in the acute and chronic phases and body weight loss in the acute phase. In vitro experiments revealed that TJ-41 treatment suppressed the LPS-induced inflammatory cytokines in BEAS-2B cells. Furthermore, TJ-41 administration activated the AMP-activated protein kinase (AMPK) pathway and inhibited the mechanistic target of the rapamycin (mTOR) pathway, both in cellular and mouse experiments. We concluded that TJ-41 administration reduced airway inflammation in the COPD mouse model, which might be regulated by the activated AMPK pathway, and inhibited the mTOR pathway.

Prevalence and clinical characteristics of Sarcopenia in older adult patients with stable chronic obstructive pulmonary disease: a cross-sectional and follow-up study

BACKGROUND

The relationship between sarcopenia and chronic obstructive pulmonary disease (COPD) has been increasingly reported, and there is some overlap regarding their clinical features and pulmonary rehabilitation (PR) strategies. No Korean study has reported the actual prevalence of sarcopenia in patients with stable COPD who are recommended for pulmonary rehabilitation. This study evaluated the prevalence and clinical features of sarcopenia in older adult outpatients with stable COPD and the changes after 6 months.

METHODS

In this cross-sectional and 6-month follow-up study, we recruited 63 males aged ≥ 65 diagnosed with stable COPD. Sarcopenia was diagnosed using the AWGS 2019 criteria, which included hand grip strength testing, bioelectrical impedance analysis, Short Physical Performance Battery administration, and Strength, Assistance with walking, Rising from a chair, Climbing stairs, and Falling screening tool administration. A 6-minute walk test (6 MWT) was conducted, forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), maximal inspiratory and expiratory pressures (MIP and MEP, respectively) and peak expiratory flow (PEF) were assessed, and patient-reported questionnaires were administered.

RESULTS

At baseline, 14 (22%) patients were diagnosed with possible sarcopenia, and eight (12.6%) were diagnosed with sarcopenia. There were significant differences in the age; body mass index; Body mass index, airflow Obstruction, Dyspnea, and Exercise index; modified Medical Research Council dyspnea scores; and International Physical Activity Questionnaire scores between the normal and sarcopenia groups. Whole-body phase angle, MIP, MEP, PEF, and 6-minute walk distance (6 MWD) also showed significant differences. Over 6 months, the proportion of patients with a reduced FEV1 increased; however, the proportion of patients with sarcopenia did not increase.

CONCLUSION

A relatively low prevalence of sarcopenia was observed in older adult outpatients with stable COPD. No significant change in the prevalence of sarcopenia was found during the 6-month follow-up period.

TRIAL REGISTRATION

The study was registered with the Clinical Research Information Service (KCT0006720). Registration date: 30/07/2021.

Chronic obstructive pulmonary disease as a risk factor for sarcopenia: A systematic review and meta-analysis

Sarcopenia prevalence and its risk factors in chronic obstructive pulmonary disease (COPD) vary partly due to definition criteria. This systematic review aimed to identify the prevalence and risk factors of sarcopenia in COPD patients. This review was registered in PROSPERO (CRD42022310750). Nine electronic databases were searched from inception to September 1st, 2022, and studies related to sarcopenia and COPD were identified. Study quality was assessed using a validated scale matched to study designs, and a meta-analysis was performed to evaluate sarcopenia prevalence. COPD patients with sarcopenia were compared to those without sarcopenia for BMI, smoking, and mMRC. The current meta-analysis included 15 studies, with a total of 7,583 patients. The overall sarcopenia prevalence was 29% [95% CI: 22%-37%], and the OR of sarcopenia in COPD patients was 1.51 (95% CI: 1.19-1.92). The meta-analysis and systematic review showed that mMRC (OR = 2.02, P = 0.04) and age (OR = 1.15, P = 0.004) were significant risk factors for sarcopenia in COPD patients. In contrast, no significant relationship was observed between sarcopenia and smoking and BMI. Nursing researchers should pay more attention to the symptomatic management of COPD and encourage patients to participate in daily activities in the early stages of the disease.

Muscle loss phenotype in COPD is associated with adverse outcomes in the UK Biobank

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory disorder with systemic consequences that can cause a muscle loss phenotype (MLP), which is characterized by the loss of muscle mass, muscle strength, or loss of both muscle and fat mass. There are limited data comparing the individual traits of MLP with clinical outcomes in a large unbiased cohort of COPD patients. Our aim was to determine the proportion of patients who met criteria for MLP in an unbiased sample of COPD patients at the population-level. We also determined if specific MLP features were associated with all-cause and COPD-related mortality.

METHODS

A retrospective population-based cohort analysis of the UK Biobank was performed. COPD was defined by a FEV1/FVC ratio < 0.7, physician established diagnosis of COPD, or those with a COPD-related hospitalization before baseline assessment. MLP included one or more of the following: 1) Low fat-free mass index (FFMI) on bioelectric impedance analysis (BIA) or 2) Appendicular skeletal muscle index (ASMI) on BIA, 3) Low muscle strength defined by handgrip strength (HGS), or 4) Low muscle and fat mass based on body mass index (BMI). Cox regression was used to determine the association between MLP and all-cause or COPD-related mortality. All models were adjusted for sex, age at assessment, ethnicity, BMI, alcohol use, smoking status, prior cancer diagnosis and FEV1/FVC ratio.

RESULTS

There were 55,782 subjects (56% male) with COPD followed for a median of 70.1 months with a mean(± SD) age at assessment of 59 ± 7.5 years, and FEV1% of 79.2 ± 18.5. Most subjects had mild (50.4%) or moderate (42.8%) COPD. Many patients had evidence of a MLP, which was present in 53.4% of COPD patients (34% by ASMI, 26% by HGS). Of the 5,608 deaths in patients diagnosed with COPD, 907 were COPD-related. After multivariate adjustment, COPD subjects with MLP had a 30% higher hazard-ratio for all-cause death and 70% higher hazard-ratio for COPD-related death.

CONCLUSIONS

Evidence of MLP is common in a large population-based cohort of COPD and is associated with higher risk for all-cause and COPD-related mortality.

Body composition impacts outcome of bronchoscopic lung volume reduction in patients with severe emphysema: a fully automated CT-based analysis

Chronic Obstructive Pulmonary Disease (COPD) is characterized by progressive and irreversible airflow limitation, with individual body composition influencing disease severity. Severe emphysema worsens symptoms through hyperinflation, which can be relieved by bronchoscopic lung volume reduction (BLVR). To investigate how body composition, assessed through CT scans, impacts outcomes in emphysema patients undergoing BLVR. Fully automated CT-based body composition analysis (BCA) was performed in patients with end-stage emphysema receiving BLVR with valves. Post-interventional muscle and adipose tissues were quantified, body size-adjusted, and compared to baseline parameters. Between January 2015 and December 2022, 300 patients with severe emphysema underwent endobronchial valve treatment. Significant improvements were seen in outcome parameters, which were defined as changes in pulmonary function, physical performance, and quality of life (QoL) post-treatment. Muscle volume remained stable (1.632 vs. 1.635 for muscle bone adjusted ratio (BAR) at baseline and after 6 months respectively), while bone adjusted adipose tissue volumes, especially total and pericardial adipose tissue, showed significant increase (2.86 vs. 3.00 and 0.16 vs. 0.17, respectively). Moderate to strong correlations between bone adjusted muscle volume and weaker correlations between adipose tissue volumes and outcome parameters (pulmonary function, QoL and physical performance) were observed. Particularly after 6-month, bone adjusted muscle volume changes positively corresponded to improved outcomes (ΔForced expiratory volume in 1 s [FEV1], r = 0.440; ΔInspiratory vital capacity [IVC], r = 0.397; Δ6Minute walking distance [6MWD], r = 0.509 and ΔCOPD assessment test [CAT], r = -0.324; all p < 0.001). Group stratification by bone adjusted muscle volume changes revealed that groups with substantial muscle gain experienced a greater clinical benefit in pulmonary function improvements, QoL and physical performance (ΔFEV1%, 5.5 vs. 39.5; ΔIVC%, 4.3 vs. 28.4; Δ6MWDm, 14 vs. 110; ΔCATpts, -2 vs. -3.5 for groups with ΔMuscle, BAR% < -10 vs. > 10, respectively). BCA results among patients divided by the minimal clinically important difference for forced expiratory volume of the first second (FEV1) showed significant differences in bone-adjusted muscle and intramuscular adipose tissue (IMAT) volumes and their respective changes after 6 months (ΔMuscle, BAR% -5 vs. 3.4 and ΔIMAT, BAR% -0.62 vs. 0.60 for groups with ΔFEV1 ≤ 100 mL vs > 100 mL). Altered body composition, especially increased muscle volume, is associated with functional improvements in BLVR-treated patients.

Systemic immune-inflammation index and all-cause and cause-specific mortality in sarcopenia: a study from National Health and Nutrition Examination Survey 1999-2018

Background

Sarcopenia, common in the elderly, often linked to chronic diseases, correlates with inflammation.The association between SII and mortality in sarcopenia patients is underexplored, this study investigates this relationship in a U.S. adult cohort.

Methods

We analyzed 1999-2018 NHANES data, focusing on 2,974 adults with sarcopenia. Mortality outcomes were determined by linking to National Death Index (NDI) records up to December 31, 2019. Using a weighted sampling design, participants were grouped into three groups by the Systemic Immune-Inflammation Index (SII). We used Cox regression models, adjusting for demographic and clinical variables, to explore SII's association with all-cause and cause-specific mortality in sarcopenia, performing sensitivity analyses for robustness.

Results

Over a median follow-up of 9.2 years, 829 deaths occurred. Kaplan-Meier analysis showed significant survival differences across SII groups. The highest SII group showed higher hazard ratios (HRs) for all-cause and cause-specific mortality in both crude and adjusted models. The highest SII group had a higher HR for all-cause(1.57, 1.25-1.98), cardiovascular(1.61, 1.00-2.58), cancer(2.13, 1.32-3.44), and respiratory disease mortality(3.21, 1.66-6.19) in fully adjusted models. Subgroup analyses revealed SII's association with all-cause mortality across various demographics, including age, gender, and presence of diabetes or cardiovascular disease. Sensitivity analyses, excluding participants with cardiovascular diseases, those who died within two years of follow-up, or those under 45 years of age, largely reflected these results, with the highest SII group consistently demonstrating higher HRs for all types of mortality in both unadjusted and adjusted models.

Conclusion

Our study is the first to demonstrate a significant relationship between SII and increased mortality risks in a sarcopenia population.

Assessment of sarcopenic obesity as a predictor of pneumonia in patients with stable schizophrenia-A prospective study

OBJECTIVE

The European Society for Clinical Nutrition and Metabolism (ESPEN) and the European Association for the Study of Obesity (EASO) recently released the first international consensus on the diagnostic criteria for Sarcopenic obesity (SO). The present study aimed to explore the ability of SO to predict the risk of pneumonia in patients with stable schizophrenia.

METHODS

This was a prospective study involving hospitalized patients with schizophrenia aged ≥50 years from two mental health centers in western China. Baseline patient data were collected from September 1 to September 30, 2020. Follow-up data on pneumonia were collected from October 2020 to October 2022. The diagnosis of SO was based on the ESPEN/EASO criteria. Patients were assessed for handgrip strength (HGS), skeletal muscle mass/weight (SMM/W), and fat mass percentage (FM%). Logistic regression analysis was used to explore the effect of SO on the risk of pneumonia in patients with stable schizophrenia.

RESULTS

A total of 320 patients with stable schizophrenia were included. Of these, 74 (23.13%) were diagnosed with SO, while 117 (36.56%) developed pneumonia. Compared with patients in the non-low HGS, non-low HGS + non-low SMM/W (or non-low HGS + low SMM/W or low HGS + non-low SMM/W) and non-SO groups, the proportions of patients with pneumonia in the low HGS (42.3% vs. 25.9%, p = 0.004), low HGS + low SMM/W (45.3% vs. 33.3%, p = 0.048), and SO (47.3% vs. 33.3%, p = 0.029) groups, respectively, were higher. However, there was no difference in the proportion of patients with pneumonia in the low SMM/W group and the obese group compared with the non-low SMM/W and non-obese groups. Further logistic regression analysis after adjustment for potential influencing factors showed that compared with the non-low HGS group, patients in the low HGS group had a higher risk of pneumonia (OR = 1.892, 95%CI: 1.096-3.264).

CONCLUSION

SO defined according to the ESPEN/EASO criteria was not found to be significantly associated with the development of pneumonia in patients with stable schizophrenia. Further verification of these results is needed with larger sample sizes and the establishment of a cutoff value for this population.

The Impact of Sarcopenia in the Long-Term Survival of Patients following Complex Endovascular Aortic Surgery for Thoracoabdominal Aortic Aneurysms

OBJECTIVES

Image-based sarcopenia has been the subject of recent studies, hypothesized as a prognostic factor for patients with thoracoabdominal aortic aneurysms.

METHODS AND MATERIALS

We conducted a single-center retrospective analysis of patients who underwent complex endovascular repair for thoracoabdominal aortic aneurysms between 2008 and 2016. CT image assessment was performed and patients were classified as sarcopenic and non-sarcopenic using two stratification methods: skeletal mass index (SMI) and total psoas muscle index (TPMI). According to sex, each patient was defined as sarcopenic if their SMI or TPMI was in the lowest third of the study group. The primary endpoint was impact of sarcopenia on perioperative mortality and long-term survival. Secondary endpoints were perioperative complications.

RESULTS

From a total of 155 patients, 135 were eligible for study. Overall, in-hospital mortality was 5.9% (8/135). The 30-day, 1-year, 3-year and 5-year mortality was 10.4% (14/135), 20% (27/135), 28.1% (38/135) and 31.1% (42/135), respectively. There was no difference in the long-term mortality rates between sarcopenic and non-sarcopenic patients regardless of the stratification method used (p = 0.4 for SMI and p = 0.2 for TPMI). According to SMI, 30-day mortality of sarcopenic patients was significantly lower in comparison to non-sarcopenic patients (1/45, 2.2% vs. 13/90, 14.4%, p = 0.028). Based on the total psoas muscle index, sarcopenic patients were at higher risk for development of pulmonary complications in comparison to non-sarcopenic patients postoperatively (p = 0.03).

CONCLUSION

Using SMI and TPMI, sarcopenia was not associated with reduced long-term survival in patients undergoing complex endovascular repair for thoracoabdominal aortic aneurysms.

Phase angle as an indicator of physical activity in patients with stable chronic obstructive pulmonary disease

OBJECTIVES

Phase angle (PhA) reflects cell membrane integrity and vitality and is an indicator of sarcopenia. PhA is associated with physical function in patients with stable chronic obstructive pulmonary disease (COPD). To our knowledge, the association between PhA and physical activity (PA) has not been investigated. Therefore, the aim of this study was to investigate whether PhA reflects PA in patients with COPD.

METHODS

This single-center, cross-sectional, observational study included 103 patients with stable COPD (87 men; mean age, 74.7 ± 8.1 y; mean forced expiratory volume in 1s %predicted value, 58.9 ± 20.4%). PhA was measured by bioelectrical impedance analysis. Patients were stratified into low (n = 54) and high (n = 49) PhA groups based on median values (4.3° ± 0.6° and 5.4° ± 0.5°, respectively). PA was calculated as the average daily duration of high-intensity light PA (HLPA; 2.0-2.9 metabolic equivalents [METs] of PA) and moderate- to vigorous-intensity PA (MVPA; >3 METs). Correlation and multivariate analyses using multiple regression analysis were performed to confirm the association between PhA and PA.

RESULTS

The high-PhA group demonstrated greater HLPA (104.4 [16.5-332.5] versus 131.3 [61.1-328.7] min, P = 0.005) and MVPA (19.5 [4.7-96.0] versus 46.6 [8.9-139.3] min, P < 0.001) than the low-PhA group. PhA was positively correlated with HLPA (r = 0.32, P < 0.001) and MVPA (r = 0.49, P < 0.001). MVPA (β = 0.178, P = 0.029) and HLPA (β = 0.158, P = 0.026) were associated with PhA independent of age, sex, body mass index, respiratory function, muscle strength, skeletal muscle mass index, and 6-min walking distance.

CONCLUSION

In patients with COPD, PhA may reflect PA as well as muscle function.

Effect of internet-based pulmonary rehabilitation on physical capacity and health-related life quality in patients with chronic obstructive pulmonary disease-a systematic review and meta-analysis

PURPOSE

Pulmonary rehabilitation (PR) is now recognized as the most effective treatments for individuals with chronic obstructive pulmonary disease (COPD), internet-based PR arises a promising method. The aim of this study was to conduct a systematic review and meta-analysis for assessing the effect of internet-based PR programs on physical capacity and health-related quality of life in patients with COPD.

MATERIALS AND METHODS

Randomized controlled trials were identified through systematically searches in PubMed, EMBASE, web of science, CENTRAL, Cochrane Library, and Google Scholar databases.

RESULTS

Twelve studies (1433 patients) were included. For physical capacity, there was no significant difference between groups was found according to the 6-min walk test (6MWT) (MD10.42, 95% CI -2.92 to 23.77, p = 0.13, I2 = 0%). For the health-related quality of life, no significant difference between groups was found regarding the St George's Respiratory Questionnaire (SGRQ) (MD -0.64, 95% CI -3.52 to 2.23, p = 0.66), COPD assessment test (CAT)(MD -0.34, 95% CI -1.62 to 0.94, p = 0.60), modified Medical Research Council scale (mMRC)(MD 0.17, 95% CI -0.06 to 0.39, p = 0.15) and Chronic Respiratory Questionnaire (CRQ)(MD 1.32 95% CI -5.88 to 8.53, p = 0.72).

CONCLUSIONS

This study has established the potential for delivery of PR via the internet in demonstrating non-inferiority of physical capacity and health-related quality of life (HRQoL) compared with conventional PR.IMPLICATIONS FOR REHABILITATIONLong-term rehabilitation training for patients with chronic obstructive pulmonary disease needs a more convenient and feasible way.In this study, internet-based rehabilitation showed similar effects as conventional rehabilitation on physical activity and health-related quality of life.Internet-based rehabilitation strategies would be helpful for this population.All internet-based rehabilitation strategies should be simple and sustainable.

Unveiling the Knowledge Frontier: A Scientometric Analysis of COPD with Sarcopenia

Objective

Numerous articles and reviews addressing the intersection of Chronic Obstructive Pulmonary Disease (COPD) with sarcopenia have been documented. However, a significant gap exists in the literature concerning scientometric analysis in this field. This study aimed to concentrate on recent research and elucidate emerging research areas through the examination of COPD with sarcopenia.

Methods

Articles in the field were systematically retrieved from the Web of Science Core Collections (WoSCC) spanning from 2003 to 2022. The analysis employed scientometric and keyword analyses through specialized software, including VOSviewer, CiteSpace, and Origin.

Results

A comprehensive analysis of 758 articles and reviews in the field of COPD with sarcopenia revealed the United States as the leading contributor in terms of publications and overall influence. Maastricht University emerged as the most prolific institution, with Schols Annemie M. W. J. being identified as the most influential scholar in this field. The International Journal of Chronic Obstructive Pulmonary Disease emerged as the most prolific journal. Notably, COPD with sarcopenia exhibits frequent associations with other diseases, underscoring the complexity of the topic and emphasizing the necessity for comprehensive treatment. Mechanistic and diagnostic aspects, particularly computed tomography, are pivotal in this research field. Osteoporosis emerges as a prospective avenue for future research, encompassing both COPD and sarcopenia. Furthermore, nutrition and physical activity are integral components for managing COPD patients with sarcopenia.

Conclusion

This study delineates the distribution of fields, the knowledge structure, and the evolution of major research topics related to COPD with sarcopenia. The identification of keyword hotspots enhances the understanding of the occurrence, development, and future study trends associated with the topic.

HDAC9 inhibition reduces skeletal muscle atrophy and enhances regeneration in mice with cigarette smoke-induced COPD

Cigarette smoke (CS) is the major risk factor for chronic obstructive pulmonary disease (COPD), and sarcopenia is one of the significant comorbidities of COPD. However, the pathogenesis of CS-related deficient skeletal muscle regeneration has yet to be clarified. The impact of CS on myoblast differentiation was examined, and then we determined which HDAC influenced the myogenic process and muscle atrophy in vitro and in vivo. Finally, we further investigated the potential mechanisms via RNA sequencing. Long-term CS exposure activated skeletal muscle primary satellite cells (SCs) while inhibiting differentiation, and defective myogenesis was also observed in C2C12 cells treated with CS extract (CSE). The level of HDAC9 changed in vitro and in vivo in CS exposure models as well as COPD patients, as detected by bioinformatics analysis. Our data showed that CSE impaired myogenic capacity and myotube formation in C2C12 cells via HDAC9. Moreover, inhibition of HDAC9 in mice exposed to CS prevented skeletal muscle dysfunction and promoted SC differentiation. The results of RNA-Seq analysis and verification indicated that HDAC9 knockout improved muscle differentiation in CS-exposed mice, probably by acting on the AKT/mTOR pathway and inhibiting the P53/P21 pathway. More importantly, the serum of HDAC9 KO mice exposed to CS alleviated the differentiation impairment of C2C12 cells caused by serum intervention in CS-exposed mice, and this effect was inhibited by LY294002 (an AKT/mTOR pathway inhibitor). These results suggest that HDAC9 plays an essential role in the defective regeneration induced by chronic exposure to CS.

Identification of genes and key pathways underlying the pathophysiological association between sarcopenia and chronic obstructive pulmonary disease

PURPOSE

Chronic obstructive pulmonary disease (COPD) patients are likely to develop sarcopenia, while the exact mechanism underlying the association between sarcopenia and COPD is still not clear. This cohort study aims to explore the genes, signaling pathways, and transcription factors (TFs) that are related to the molecular pathogenesis of sarcopenia and COPD.

METHODS

According to the strict inclusion criteria, two gene sets (GSE8479 for sarcopenia and GSE76925 for COPD) were obtained from the Gene Expression Omnibus (GEO) platform. Overlapping differentially expressed genes (DEGs) in sarcopenia and COPD were detected, and comprehensive bioinformatics analysis was conducted, including functional annotation, enrichment analysis of Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG), construction of a protein-protein interaction (PPI) network, co-expression analysis, identification and validation of hub genes, and TFs prediction and verification.

RESULTS

In total, 118 downregulated and 92 upregulated common DEGs were detected. Functional analysis revealed that potential pathogenesis involves oxidoreductase activity and ferroptosis. Thirty hub genes were detected, and ATP metabolic process and oxidative phosphorylation were identified to be closely related to the hub genes. Validation analysis revealed that SAA1, C3, and ACSS2 were significantly upregulated, whereas ATF4, PPARGC1A, and MCTS1 were markedly downregulated in both sarcopenia and COPD. In addition, six TFs (NFKB1, RELA, IRF7, SP1, MYC, and JUN) were identified to regulate the expression of these genes, and SAA1 was found to be coregulated by NFKB1 and RELA.

CONCLUSION

This study uncovers potential common mechanisms of COPD complicated by sarcopenia. The hub gene SAA1 and the NF-κB signaling pathway could be involved, and oxidative phosphorylation and ferroptosis might be important contributors to this comorbidity.

Pulmonary Rehabilitation for People With Persistent Symptoms After COVID-19

TOPIC IMPORTANCE

COVID-19 can cause ongoing and persistent symptoms (such as breathlessness and fatigue) that lead to reduced functional capacity. There are parallels in symptoms and functional limitations in adults with post-COVID symptoms and adults with chronic respiratory diseases. Pulmonary rehabilitation is a key treatment for adults with chronic respiratory diseases, with the aims to improve symptom management and increase functional capacity. Given the similarities in presentation and aims, a pulmonary rehabilitation program may be optimal to meet the needs of those with ongoing symptoms after COVID-19.

REVIEW FINDINGS

Aerobic and strength training has shown benefit for adults living with long COVID, although there is little evidence on structured education in this population. Breathing pattern disorder is common in adults with long COVID, and considerations on treatment before rehabilitation, or alongside rehabilitation, are necessary. Considerations on postexertional malaise are important in this population, and evidence from the chronic fatigue syndrome literature supports the need for individualization of exercise programs, and considerations for those who have an adverse reaction to activity and/or exercise.

SUMMARY

This narrative review summarizes the current evidence on pulmonary rehabilitation programs in a long-COVID population. Where the evidence is lacking in long COVID the supporting evidence of these programs in chronic respiratory diseases has highlighted the importance of aerobic and strength training, considerations for fatigue, potential mechanisms for immunology improvement, and management of breathing pattern disorders in these programs.

Prognostic value of the serum creatinine/cystatin C ratio in patients with chronic obstructive pulmonary disease

BACKGROUND

Sarcopenia, characterized by skeletal muscle atrophy and physical inactivity, is a manifestation of chronic obstructive pulmonary disease (COPD) and is associated with a poor prognosis. The serum creatinine (Cr)/cystatin C (CysC) ratio has been proposed as a marker of sarcopenia, given its correlation with total skeletal muscle mass, and as a prognostic indicator in COPD. This study aimed to evaluate the usefulness of the serum Cr/CysC ratio as a prognostic determinant in these patients.

METHODS

A total of 124 outpatients with COPD were enrolled in this study. Their serum Cr and CysC levels were measured. Survival time analyses were conducted to compare mortality rates between the low and high serum Cr/CysC ratio groups. Multivariate analysis was performed to investigate the association between various factors.

RESULTS

Using a serum Cr/CysC cut-off value of 0.885, the mortality rate (per 1000 person-years) for overall mortality was significantly higher in the low serum Cr/CysC ratio group (69.2 versus 28.6; hazard ratio, 2.47; 95% confidence interval, 1.06-5.79; p < 0.05). Similarly, the mortality rate due to respiratory disease was also higher (37.8 versus 8.2; hazard ratio, 4.68; 95% confidence interval, 1.05-20.9; p < 0.05). Multivariate Cox proportional hazards analysis revealed that serum Cr/CysC was an independent risk factor for respiratory disease mortality, regardless of age and airflow limitations.

CONCLUSIONS

The serum Cr/CysC ratio could be a valuable clinical parameter for identifying sarcopenia and severe airflow obstruction. The study findings highlight the utility of this ratio as a prognostic predictor in patients with COPD.

Revisiting Skeletal Muscle Dysfunction and Exercise in Chronic Obstructive Pulmonary Disease: Emerging Significance of Myokines

Skeletal muscle dysfunction (SMD) is the most significant extrapulmonary complication and an independent prognostic indicator in patients with chronic obstructive pulmonary disease (COPD). Myokines, such as interleukin (IL)-6, IL-15, myostatin, irisin, and insulin-like growth factor (IGF)-1, play important roles in skeletal muscle mitochondrial function, protein synthesis and breakdown balance, and regeneration of skeletal muscles in COPD. As the main component of pulmonary rehabilitation, exercise can improve muscle strength, muscle endurance, and exercise capacity in patients with COPD, as well as improve the prognosis of SMD and COPD by regulating the expression levels of myokines. The mechanisms by which exercise regulates myokine levels are related to microRNAs. IGF-1 expression is upregulated by decreasing the expression of miR-1 or miR-29b. Myostatin downregulation and irisin upregulation are associated with increased miR-27a expression and decreased miR-696 expression, respectively. These findings suggest that myokines are potential targets for the prevention and treatment of SMD in COPD. A comprehensive analysis of the role and regulatory mechanisms of myokines can facilitate the development of new exercise-based therapeutic approaches for patients with COPD.

Predictors of Success of Inpatient Pulmonary Rehabilitation Program in COPD Patients

Purpose

Pulmonary rehabilitation programs (PR) are an important part of the comprehensive treatment of patients with chronic pulmonary diseases. Patients respond individually to PR. The aim of this study is to identify potential predictors of success of PR to recognise patients who benefit most and to uncover possible reasons for poor response to PR.

Patients and Methods

We included 121 patients with chronic obstructive pulmonary disease (COPD) who completed our 4-week inpatient PR without any exacerbations of disease during PR that could potentially affect PR outcomes. Improvement in distance of ≥30 m on the 6-minute walk test (6MWT) after PR was chosen as a primary marker of physical success. Ninety-one patients achieved improvement of ≥30 m on the 6MWT and were thus considered good responders, and 30 patients were poor responders with improvement in the distance of <30 m on the 6MWT.

Results

We compared baseline clinical characteristics, medication, lung function, physical capacity, body composition, and laboratory blood tests between groups of good and poor responders. The most prominent differences between groups were associated with differences in baseline body composition and erythrocyte-related parameters. Good responders had significantly lower body water content (p = 0.042) and higher body weight (p = 0.036), body fat content (p = 0.049), dry lean mass (p = 0.021), haemoglobin levels (p = 0.040), erythrocyte count (p = 0.017), haematocrit (p = 0.030) and iron level (p = 0.028).

Conclusion

A more muscular body composition and a higher ability to transport oxygen from the blood to the muscles could be beneficial for the outcome of PR.

Clinical impacts of sarcopenic obesity on chronic obstructive pulmonary disease: a cross-sectional study

BACKGROUND

Sarcopenia and obesity are two abnormal body composition phenotypes, and sarcopenic obesity (SO) is characterized by both low skeletal muscle mass (sarcopenia) and high adiposity (obesity). SO negatively influences the clinical status of patients with chronic obstructive pulmonary disease (COPD). However, the studies exploring the prevalence and clinical effects of SO in COPD patients are limited. Our study aimed to elucidate the prevalence and impact of SO on COPD patients.

METHODS

In this cross-sectional study, the pulmonary function, St. George's Respiratory Questionnaire, exercise tolerance, body composition, and serum levels of resistin and TNF-α were assessed in 198 COPD patients. The clinical value of serum resistin and TNF-α for predicting SO in patients with COPD was evaluated.

RESULTS

In the 198 patients with COPD, the prevalence rates of sarcopenia, obesity, and SO in COPD patients were 27.27%, 29.8%, and 9.6%, respectively. Patients with SO experienced more severe symptoms of dyspnea and worse health related quality of life. The expression of resistin increased in patients with SO compared to other patients. The AUC value of serum resistin level for predicting SO was 0.870 (95% CI: 0.799-0.940). BMI (OR: 1.474, 95% CI: 1.124-1.934) and resistin (OR: 1.001, 95% CI: 1.000-1.002) levels were independent risk factors of SO in patients with COPD in Multivariate analysis.

CONCLUSION

The prevalence rates of SO in COPD patients was 9.6%. COPD accompanied by SO is significantly associated with worse pulmonary function and poor physical performance. Serum resistin may be a potential adjunct for predicting SO in COPD patients.

Sarcopenia, a condition shared by various diseases: can we alleviate or delay the progression?

Sarcopenia is a severe condition common to various chronic diseases and it is reckoned as a major health problem. It encompasses many different molecular mechanisms that have been for a while discovered but not definitely clarified. Although sarcopenia is a disability status that leads to serious health consequences, the scarcity of suitable animal models has curtailed research addressing this disorder. Another limitation in the field of clinical investigation of sarcopenic patients is the lack of a generally accepted definition coupled with the difficulty of adopting common diagnostic criteria. In fact, both do not permit to clarify the exact prevalence rate and consequently limit physicians to establish any kind of therapeutical approach or, when possible, to adopt preventive measures. Unfortunately, there is no standardized cure, apart from doing more physical activity and embracing a balanced diet, but newly discovered substances start being considered. In this review, authors try to give an overview addressing principal pathways of sarcopenia and offer critical features of various possible interventions.

Association Between Sarcopenia and Chronic Renal Failure (Overt and Concealed) in Chronic Obstructive Pulmonary Disease (COPD) Patients: A Cross-Sectional Study

Background Sarcopenia, a syndrome characterized by a progressive decline in skeletal muscle mass, strength, and function, is frequently associated with chronic diseases such as chronic obstructive pulmonary disease (COPD). Chronic kidney disease (CKD) is a prevalent condition among patients with sarcopenia. Reports suggest that between 15% and 55% of stable COPD patients have sarcopenia. Therefore, the present study aims to determine the association between sarcopenia and chronic renal failure (overt and concealed) in COPD patients. Methodology This institutional-based cross-sectional study was conducted on patients diagnosed with COPD. Hospitalized adult COPD patients who gave consent were included. Sociodemographic information such as age, gender, residence, and prolonged length of stay in the hospital (categorized by a median of 10 days, considering its data distribution in our sample) was obtained using electronic medical records. Skeletal muscle %, visceral fat %, and body fat % were calculated using a bio-electrical impedance analysis device (Omron Body Composition Monitor, Model HBF-702T). Additionally, the strength of the hand grip was measured using a hand dynamometer. Sarcopenia was assessed following the criteria set by the Asian Working Group on Sarcopenia (AWGS). Chronic renal failure (CRF) was assessed by calculating the glomerular filtration rate (GFR) using the Modification of Diet in Renal Disease (MDRD) Study Group equation. Quantitative data were compared using an independent sample t-test. The association was determined using chi-square and multivariate logistic regression analyses. A p-value of <0.05 was considered significant. Results The study found that the proportion of sarcopenia in COPD patients was 52%, with overt and concealed CRF prevalence rates of 31.5% and 27%, respectively. Sarcopenic individuals had significantly lower FEV1 and FEV1/FVC compared to non-sarcopenic patients. The incidence of sarcopenia significantly increased with rising BODE index (body mass index (BMI, B), airflow obstruction (O) as measured by the post-bronchodilator FEV1 (percentage of predicted value), dyspnea (D) assessed by the modified Medical Research Council (MMRC) score, and exercise tolerance (E) measured by 6-minute walking distance) and mMRC (modified Medical Research Council dyspnea scale) dyspnea scale scores. Both concealed CRF and overt CRF patients had four times higher odds of having sarcopenia (AOR=4). Conclusion The study reveals a high prevalence of sarcopenia and provides evidence for the association between sarcopenia and chronic renal failure in COPD patients. These findings underscore the importance of early detection and management of sarcopenia and CRF in COPD patients to optimize their clinical outcomes.

Association between sarcopenia and exercise capacity in patients with pulmonary hypertension without left heart disease

BACKGROUND

Pulmonary hypertension (PH) has recently been described as a complex clinical syndrome affecting multiple organ systems, including the heart, lungs, and skeletal muscle, each of which plays an important role in exercise capacity. However, the relationship between exercise capacity and skeletal muscle abnormalities in patients with PH has not been fully elucidated.

METHODS

We retrospectively analysed the exercise capacity and measures of skeletal muscle of 107 patients with PH without left heart disease (mean age 63 ± 15 years, 32.7% males, n = 30/6/66/5 in the clinical classification Group 1/3/4/5).

RESULTS

Sarcopenia, low appendicular skeletal muscle mass index, low grip strength, and slow gait speed, determined by international criteria, were found in 15 (14.0%), 16 (15.0%), 62 (57.9%), and 41 (38.3%) patients, respectively. The mean 6-min walk distance of all patients was 436 ± 134 m and was independently associated with sarcopenia (standardised β = -0.292, p < 0.001). All patients with sarcopenia showed reduced exercise capacity defined as 6-min walk distance < 440 m. Multivariable logistic regression analysis showed that each of the components of sarcopenia was associated with reduced exercise capacity (adjusted odds ratio and 95% confidence interval of appendicular skeletal muscle mass index: 0.39 [0.24-0.63] per 1 kg/m2, p = 0.006, grip strength: 0.83 [0.74-0.94] per 1 kg, p = 0.003, and gait speed: 0.31 [0.18-0.51] per 0.1 m/s, p < 0.001).

CONCLUSIONS

Sarcopenia and its components are associated with reduced exercise capacity in patients with PH. A multifaceted evaluation may be important in the management of reduced exercise capacity in patients with PH.

Deep learning-based pectoralis muscle volume segmentation method from chest computed tomography image using sagittal range detection and axial slice-based segmentation

The pectoralis muscle is an important indicator of respiratory muscle function and has been linked to various parenchymal biomarkers, such as airflow limitation severity and diffusing capacity for carbon monoxide, which are widely used in diagnosing parenchymal diseases, including asthma and chronic obstructive pulmonary disease. Pectoralis muscle segmentation is a method for measuring muscle volume and mass for various applications. The segmentation method is based on deep-learning techniques that combine a muscle area detection model and a segmentation model. The training dataset for the detection model comprised multichannel images of patients, whereas the segmentation model was trained on 7,796 cases of the computed tomography (CT) image dataset of 1,841 patients. The dataset was expanded incrementally through an active learning process. The performance of the model was evaluated by comparing the segmentation results with manual annotations by radiologists and the volumetric differences between the CT image datasets of the same patients. The results indicated that the machine learning model is promising in segmenting the pectoralis major muscle, with good agreement between the automatic segmentation and manual annotations by radiologists. The training accuracy and loss values of the validation set were 0.9954 and 0.0725, respectively, and for segmentation, the loss value was 0.0579. This study shows the potential clinical usefulness of the machine learning model for pectoralis major muscle segmentation as a quantitative biomarker for various parenchymal and muscular diseases.

CT-Derived Deep Learning-Based Quantification of Body Composition Associated with Disease Severity in Chronic Obstructive Pulmonary Disease

Purpose

Our study aimed to evaluate the association between automated quantified body composition on CT and pulmonary function or quantitative lung features in patients with chronic obstructive pulmonary disease (COPD).

Materials and Methods

A total of 290 patients with COPD were enrolled in this study. The volume of muscle and subcutaneous fat, area of muscle and subcutaneous fat at T12, and bone attenuation at T12 were obtained from chest CT using a deep learning-based body segmentation algorithm. Parametric response mapping-derived emphysema (PRMemph), PRM-derived functional small airway disease (PRMfSAD), and airway wall thickness (AWT)-Pi10 were quantitatively assessed. The association between body composition and outcomes was evaluated using Pearson's correlation analysis.

Results

The volume and area of muscle and subcutaneous fat were negatively associated with PRMemph and PRMfSAD (p < 0.05). Bone density at T12 was negatively associated with PRMemph (r = -0.1828, p = 0.002). The volume and area of subcutaneous fat and bone density at T12 were positively correlated with AWT-Pi10 (r = 0.1287, p = 0.030; r = 0.1668, p = 0.005; r = 0.1279, p = 0.031). However, muscle volume was negatively correlated with the AWT-Pi10 (r = -0.1966, p = 0.001). Muscle volume was significantly associated with pulmonary function (p < 0.001).

Conclusion

Body composition, automatically assessed using chest CT, is associated with the phenotype and severity of COPD.

Role of nutrition in patients with coexisting chronic obstructive pulmonary disease and sarcopenia

Chronic obstructive pulmonary disease (COPD) is one of the most common chronic diseases in the elderly population and is characterized by persistent respiratory symptoms and airflow obstruction. During COPD progression, a variety of pulmonary and extrapulmonary complications develop, with sarcopenia being one of the most common extrapulmonary complications. Factors that contribute to the pathogenesis of coexisting COPD and sarcopenia include systemic inflammation, hypoxia, hypercapnia, oxidative stress, protein metabolic imbalance, and myocyte mitochondrial dysfunction. These factors, individually or in concert, affect muscle function, resulting in decreased muscle mass and strength. The occurrence of sarcopenia severely affects the quality of life of patients with COPD, resulting in increased readmission rates, longer hospital admission, and higher mortality. In recent years, studies have found that oral supplementation with protein, micronutrients, fat, or a combination of nutritional supplements can improve the muscle strength and physical performance of these patients; some studies have also elucidated the possible underlying mechanisms. This review aimed to elucidate the role of nutrition among patients with coexisting COPD and sarcopenia.

The impact of sarcopenia on the outcome of patients with left-sided colon and rectal cancer after curative surgery

BACKGROUND

The impact of sarcopenia on the outcome of patients with left-sided colon and rectal cancer has not been exhaustively investigated. Thus, the present study was performed to evaluate the effect of sarcopenia on the outcome of patients with left-sided colon and rectal cancer.

METHODS

Patients with pathologically diagnosed stage I, II and III left-sided colon or rectal cancer who had undergone curative surgery between January 2008 and December 2014 were retrospectively reviewed. The psoas muscle index (PMI) identified by 3D-image analysis of computed tomographic images was the criterion used to diagnose sarcopenia. The cut-off value recommended by Hamaguchi (PMI value < 6.36 cm2/m2 for men and < 3.92 cm2/m2 for women) was adopted to confirm the diagnosis of sarcopenia. According to the PMI, each patient was divided into the sarcopenia group (SG) or the nonsarcopenia group (NSG). Then, the SG was compared with the NSG in terms of postoperative outcomes.

RESULTS

Among the 939 patients included, 574 (61.1%) were confirmed to have preoperative sarcopenia. Initially, it was demonstrated that the SG was not significantly different from the NSG in terms of most baseline characteristics except for a lower body mass index (BMI) (P < 0.001), a larger tumour size (P < 0.001) and more weight loss (more than 3 kg in the last three months) (P = 0.033). The SG had a longer hospital stay after surgery (P = 0.040), more intraoperative blood transfusions (P = 0.035), and higher incidence of anastomotic fistula (P = 0.027), surgical site infection (SSI) (P = 0.037) and hypoalbuminemia (P = 0.022), 30-day mortality (P = 0.042) and 90-day mortality (P = 0.041). The SG had significantly worse overall survival (OS) (P = 0.016) and recurrence-free survival (RFS) (P = 0.036) than the NSG. Subsequently, Cox regression analysis revealed that preoperative sarcopenia was an independent predictive factor for worse OS (P = 0.0211, HR = 1.367, 95% CI: 1.049-1.782) and RFS (P = 0.045, HR = 1.299, 95% CI: 1.006-1.677).

CONCLUSION

Preoperative sarcopenia adversely affects the outcome of patients with left-sided colon and rectal cancer, and preoperative nutrition supplementation may help us improve their long-term and short-term outcomes.

Gaining muscle mass in COPD: a work in progress

Interventions to improve muscle mass in COPD remain limited to exercise and nutrition. As novel drugs show promise, there should be focus on identifying target subgroups of patients, strategies to combine interventions and optimise outcome measures. https://bit.ly/3WI5Sjg.

When GETomics meets aging and exercise in COPD

The term GETomics has been recently proposed to illustrate that human health and disease are actually the final outcome of many dynamic, interacting and cumulative gene (G) - environment (E) interactions that occur through the lifetime (T) of the individual. According to this new paradigm, the final outcome of any GxE interactions depends on both the age of the individual at which such GxE interaction occurs as well as on the previous, cumulative history of previous GxE interactions through the induction of epigenetic changes and immune memory (both lasting overtime). Following this conceptual approach, our understanding of the pathogenesis of chronic obstructive pulmonary disease (COPD) has changed dramatically. Traditionally believed to be a self-inflicted disease induced by tobacco smoking occurring in older men and characterized by an accelerated decline of lung function with age, now we understand that there are many other risk factors associated with COPD, that it occurs also in females and young individuals, that there are different lung function trajectories through life, and that COPD is not always characterized by accelerated lung function decline. In this paper we discuss how a GETomics approach to COPD may open new perspectives to better understand its relationship with exercise limitation and the ageing process.

Nutritional State and COPD: Effects on Dyspnoea and Exercise Tolerance

Chronic Obstructive Pulmonary Disease (COPD) is a disease that is spreading worldwide and is responsible for a huge number of deaths annually. It is characterized by progressive and often irreversible airflow obstruction, with a heterogeneous clinical manifestation based on disease severity. Along with pulmonary impairment, COPD patients display different grades of malnutrition that can be linked to a worsening of respiratory function and to a negative prognosis. Nutritional impairment seems to be related to a reduced exercise tolerance and to dyspnoea becoming a major determinant in patient-perceived quality of life. Many strategies have been proposed to limit the effects of malnutrition on disease progression, but there are still limited data available to determine which of them is the best option to manage COPD patients. The purpose of this review is to highlight the main aspects of COPD-related malnutrition and to underline the importance of poor nutritional state on muscle energetics, exercise tolerance and dyspnoea.

Usefulness of the Measurement of Psoas Muscle Volume for Sarcopenia Diagnosis in Patients with Liver Disease

Computed tomography (CT) is often used in the diagnosis of sarcopenia. In this study, we validated the assessment of sarcopenia by the psoas muscle volume using versatile software. The study involved a retrospective analysis of data from 190 patients with liver disease who underwent grip-strength testing and abdominal pelvic computed tomography. To assess sarcopenia, SYNAPSE 3D was used to obtain the skeletal muscle index, the psoas muscle index (PMI), and the simple method. We also used the recently proposed PMI cutoff values, for which the usefulness has been evaluated (O-PMI). The cutoff value of the psoas muscle volume index (PMVI) was determined using one of the diagnostic methods as the gold standard. All diagnostic methods showed that patients with sarcopenia had shorter survival, with O-PMI having the highest hazard ratio (HR) (HR, 6.12; 95% confidence interval [CI], 2.6–14.41; p < 0.001). Even when sarcopenia could not be diagnosed by O-PMI, low PMVI was associated with shorter survival (HR, 3.53; 95% CI, 1.34–9.32; p = 0.01). PMVI may be useful in the evaluation of sarcopenia, including the identification of poor overall survival in cases that cannot be diagnosed by O-PMI, which is considered more useful than PMI.

A Nomogram for Optimizing Sarcopenia Screening in Community-dwelling Older Adults: AB3C Model

OBJECTIVES

Sarcopenia is associated with significantly higher mortality risk, and earlier detection of sarcopenia has remarkable public health benefits. However, the model that predicts sarcopenia in the community has yet to be well identified. The study aimed to develop a nomogram for predicting the risk of sarcopenia and compare the performance with 3 sarcopenia screen models in community-dwelling older adults in China.

DESIGN

Cross-sectional study.

SETTING AND PARTICIPANTS

A total of 966 community-dwelling older adults.

METHODS

A total of 966 community-dwelling older adults were enrolled in the study, with 678 participants grouped into the Training Set and 288 participants grouped into the Validation Set according to a 7:3 randomization. Predictors were identified in the Training Set by univariate and multivariate logistic regression and then combined into a nomogram to predict the risk of sarcopenia. The performance of this nomogram was assessed by calibration, discrimination, and clinical utility.

RESULTS

Age, body mass index, calf circumference, congestive heart failure, and chronic obstructive pulmonary disease were demonstrated to be predictors for sarcopenia. The nomogram (named as AB3C model) that was constructed based on these predictors showed excellent calibration and discrimination in the Training Set with an area under the receiver operating characteristic curve (AUC) of 0.930. The nomogram also showed perfect calibration and discrimination in the Validation Set with an AUC of 0.897. The clinical utility of the nomogram was supported by decision curve analysis. Comparing the performance with 3 sarcopenia screen models (SARC-F, Ishii, and Calf circumference), the AB3C model outperformed the other models regarding sensitivity and AUC.

CONCLUSIONS AND IMPLICATIONS

AB3C model, an easy-to-apply and cost-effective nomogram, was developed to predict the risk of sarcopenia, which may contribute to optimizing sarcopenia screening in community settings.

Clinical Impacts of Interventions for Physical Activity and Sedentary Behavior on Patients with Chronic Obstructive Pulmonary Disease

Recently, physical activity has increasingly become the focus in patients with chronic obstructive airway disease (COPD) because it is a strong predictor of COPD-related mortality. In addition, sedentary behavior, which is included as a category of physical inactivity including such behaviors as sitting or lying down, has an independent clinical impact on COPD patients. The present review examines clinical data related to physical activity, focusing on the definition, associated factors, beneficial effects, and biological mechanisms in patients with COPD and with respect to human health regardless of COPD. The data related to how sedentary behavior is associated with human health and COPD outcomes are also examined. Lastly, possible interventions to improve physical activity or sedentary behavior, such as bronchodilators and pulmonary rehabilitation with behavior modification, to ameliorate the pathophysiology of COPD patients are described. A better understanding of the clinical impact of physical activity or sedentary behavior may lead to the planning of a future intervention study to establish high-level evidence.

Skeletal Muscle Adiposity and Lung Function Trajectory in the Severe Asthma Research Program

Rationale: Extrapulmonary manifestations of asthma, including fatty infiltration in tissues, may reflect systemic inflammation and influence lung function and disease severity. Objectives: To determine if skeletal muscle adiposity predicts lung function trajectory in asthma. Methods: Adult SARP III (Severe Asthma Research Program III) participants with baseline computed tomography imaging and longitudinal postbronchodilator FEV1% predicted (median follow-up 5 years [1,132 person-years]) were evaluated. The mean of left and right paraspinous muscle density (PSMD) at the 12th thoracic vertebral body was calculated (Hounsfield units [HU]). Lower PSMD reflects higher muscle adiposity. We derived PSMD reference ranges from healthy control subjects without asthma. A linear multivariable mixed-effects model was constructed to evaluate associations of baseline PSMD and lung function trajectory stratified by sex. Measurements and Main Results: Participants included 219 with asthma (67% women; mean [SD] body mass index, 32.3 [8.8] kg/m2) and 37 control subjects (51% women; mean [SD] body mass index, 26.3 [4.7] kg/m2). Participants with asthma had lower adjusted PSMD than control subjects (42.2 vs. 55.8 HU; P < 0.001). In adjusted models, PSMD predicted lung function trajectory in women with asthma (β = -0.47 Δ slope per 10-HU decrease; P = 0.03) but not men (β = 0.11 Δ slope per 10-HU decrease; P = 0.77). The highest PSMD tertile predicted a 2.9% improvement whereas the lowest tertile predicted a 1.8% decline in FEV1% predicted among women with asthma over 5 years. Conclusions: Participants with asthma have lower PSMD, reflecting greater muscle fat infiltration. Baseline PSMD predicted lung function decline among women with asthma but not men. These data support an important role of metabolic dysfunction in lung function decline.

Impact of Body Composition and Sarcopenia on Mortality in Chronic Obstructive Pulmonary Disease Patients

BACKGROUND

Patients with chronic obstructive pulmonary disease (COPD) have alterations in body composition, such as low cell integrity, body cell mass, and disturbances in water distribution evidenced by higher impedance ratio (IR), low phase angle (PhA), as well as low strength, low muscle mass, and sarcopenia. Body composition alterations are associated with adverse outcomes. However, according to the European Working Group on Sarcopenia in Older People 2 (EWGSOP2), the impact of these alterations on mortality in COPD patients is not well-established. Our aims were to evaluate whether low strength, low muscle mass, and sarcopenia impacted mortality in COPD patients.

METHODS

A prospective cohort study performance was conducted with COPD patients. Patients with cancer, and asthma were excluded. Body composition was assessed by bioelectrical impedance analysis. Low strength and muscle mass, and sarcopenia were defined according to EWGSOP2.

RESULTS

240 patients were evaluated, of whom 32% had sarcopenia. The mean age was 72.32 ± 8.24 years. The factors associated with lower risk of mortality were handgrip strength (HR:0.91, CI 95%; 0.85 to 0.96, p = 0.002), PhA (HR:0.59, CI 95%; 0.37 to 0.94, p = 0.026) and exercise tolerance (HR:0.99, CI 95%; 0.992 to 0.999, p = 0.021), while PhA below the 50th percentile (HR:3.47, CI 95%; 1.45 to 8.29, p = 0.005), low muscle strength (HR:3.49, CI 95%; 1.41 to 8.64, p = 0.007) and sarcopenia (HR:2.10, CI 95%; 1.02 to 4.33, p = 0.022) were associated with a higher risk of mortality.

CONCLUSION

Low PhA, low muscle strength, and sarcopenia are independently associated with poor prognosis in COPD patients.

Relationship between asthma and sarcopenia in the elderly: a nationwide study from the KNHANES

OBJECTIVE

Few studies have investigated the relationship between asthma and sarcopenia. We aimed to examine the relationship between asthma and sarcopenia in a community-dwelling geriatric population, especially regarding lung function and asthma control.

METHODS

A cross-sectional dataset from the Korean National Health and Nutrition Examination Survey 2008-2011 was utilized. Data regarding asthma history, age at asthma onset, recent asthma exacerbations, and hospitalization for asthma exacerbations were obtained using structured questionnaires. Appendicular skeletal muscle was calculated as the sum of the skeletal muscle mass, and physical activity was assessed using the International Physical Activity Questionnaire.

RESULTS

Asthma presented an estimated incidence of 6.17 ± 0.37% in the elderly. Groups were divided and analyzed according to asthma, muscle mass, and physical activity. Sarcopenia was associated with aging, male sex, smoking history, low body mass index (BMI), and reduced lung function with or without asthma. Sarcopenic asthma had a younger onset and reduced physical activity than non-sarcopenic asthma. Obstructive patterns were more frequent in asthmatics exhibiting low or moderate physical activity levels than in those with high activity, but asthma control was not associated with sarcopenia and physical activity. Multivariate logistic regression analyses showed that compared with control, sarcopenic asthma was associated with FEV1 < 60%, and airway obstruction, and with aging, male, and lower BMI, compared with non-sarcopenic asthma.

CONCLUSIONS

Our findings suggest that decreased muscle mass and physical activity levels contribute to reduced lung function in elderly asthmatics. Furthermore, sarcopenic asthma was associated with aging, low BMI, and reduced lung function in the elderly.

Frailty and Mortality Risk in COPD: A Cohort Study Comparing the Fried Frailty Phenotype and Short Physical Performance Battery

Background

Identifying frailty in people with chronic obstructive pulmonary disease (COPD) is deemed important, yet comparative characteristics of the most commonly used frailty measures in COPD are unknown. This study aimed to compare how the Fried Frailty Phenotype (FFP) and Short Physical Performance Battery (SPPB) characterise frailty in people with stable COPD, including prevalence of and overlap in identification of frailty, disease and health characteristics of those identified as living with frailty, and predictive value in relation to survival time.

Methods

Cohort study of people with stable COPD attending outpatient clinics. Agreement between frailty classifications was described using Cohen's Kappa. Disease and health characteristics of frail versus not frail participants were compared using t-, Mann-Whitney U and Chi-Square tests. Predictive value for mortality was examined with multivariable Cox regression.

Results

Of 714 participants, 421 (59%) were male, mean age 69.9 years (SD 9.7), mean survival time 2270 days (95% CI 2185-2355). Similar proportions were identified as frail using the FFP (26.2%) and SPPB (23.7%) measures; classifications as frail or not frail matched in 572 (80.1%) cases, showing moderate agreement (Kappa = 0.469, SE = 0.038, p < 0.001). Discrepancies seemed driven by FFP exhaustion and weight loss criteria and the SPPB balance component. People with frailty by either measure had worse exercise capacity, health-related quality of life, breathlessness, depression and dependence in activities of daily living. In multivariable analysis controlling for the Age Dyspnoea Obstruction index, sex, BMI, comorbidities and exercise capacity, both the FFP and SPPB had predictive value in relation to mortality (FFP aHR = 1.31 [95% CI 1.03-1.66]; SPPB aHR = 1.29 [95% CI 0.99-1.68]).

Conclusion

In stable COPD, both the FFP and SPPB identify similar proportions of people living with/without frailty, the majority with matching classifications. Both measures can identify individuals with multidimensional health challenges and increased mortality risk and provide additional information alongside established prognostic variables.

Effect of intravenous ferric carboxymaltose on exercise capacity and quality of life in patients with COPD : A pilot study

BACKGROUND AND OBJECTIVE

Chronic obstructive pulmonary disease (COPD) is associated with reduced exercise capacity. In COPD iron deficiency is found in up to 50% of patients and may impair exercise capacity, the potential therapeutic effect is yet unknown. We aimed to estimate the beneficial effect of intravenous ferric carboxymaltose on exercise capacity and quality of life in patients with COPD.

METHODS

In this non-randomized, interrupted time series pilot trial we enrolled outpatients with stable COPD (GOLD II and III) and nonanemic iron deficiency (i.e., ferritin level < 100 μg/l or ferritin level 100-300 μg/l if transferrin saturation < 20%). Patients with cardiovascular-or inflammatory diseases were excluded. Participants performed 6‑minute walking test (6-MWT) and cardiopulmonary exercise testing (CPET) and completed the St. George's Respiratory Questionnaire (SGRQ).

RESULTS

From 35 screened patients, 11 (72% male, 63 ± 8 years, FEV1%predicted 44 ± 14) were included. Mean ferritin and hemoglobin were 70 ± 41 µg/l and 13.8 ± 1.7 g/dl, respectively. Four weeks after iron administration the 6‑MWT distance increased by 34.7 ± 34.4 m (95% CI, 10.0-59.3); p = 0.011. The VO2max increased by 1.87 ± 1.2 ml/kg/min (95% CI, 0.76-3); p = 0.006. Mean score of SGRQ was reduced by 7.56 ± 6.12 units (95% CI, 3 to 11); p = 0.004. The insignificant alteration in hemoglobin did not correlate with increase in exercise capacity.

CONCLUSION

Administration of intravenous iron was associated with improved exercise capacity and quality of life in stable COPD patients independent of hemoglobin. Our data provide a basis to calculate a statistically sufficient sample size for a randomized controlled follow-up study.

Prevalence of sarcopenia in patients with COPD through different musculature measurements: An updated meta-analysis and meta-regression

Aim

Chronic obstructive pulmonary disease (COPD) patients vary widely in terms of the prevalence of sarcopenia, which is partially attributed to differences in diagnostic criteria and disease severity. There are several different musculature measurements that are used to quantify sarcopenia. This study included published literature for meta-analysis to assess the sarcopenia prevalence in COPD patients and correlate the disease with the clinical characteristics of such patients.

Methods

A comprehensive review of the English and Chinese literature on sarcopenia prevalence in COPD patients was conducted using electronic databases such as China National Knowledge Infrastructure (CNKI), Web of Science, Cochrane Library, EMBASE, PubMed, and Wanfang. Two researchers analyzed the studies for Newcastle-Ottawa Scale. The software Stata 11.0 was employed for the analysis of the acquired data. The standard mean differences method was utilized for the estimation and quantification of the effect size. Furthermore, a fixed- or random-effects model was employed for conducting a combined analysis.

Results

In total, 56 studies were included as per the specific inclusion criteria. The resulting data of the assessed COPD patients in this research indicated a 27% prevalence of sarcopenia. Further analysis of subgroups was executed per disease severity, ethnicity, diagnostic criteria, gender, and age. Per these findings, increased disease severity elevated the prevalence of sarcopenia. The Latin American and Caucasian populations indicated an increased prevalence of sarcopenia. In addition, the prevalence of sarcopenia was related to diagnostic criteria and definition. Male COPD patients had a higher prevalence of sarcopenia than female COPD patients. COPD patients with an average age greater than 65 had a slightly higher prevalence of sarcopenia. COPD patients with comorbid sarcopenia had poorer pulmonary function, activity tolerance, and clinical symptoms than patients with COPD alone.

Conclusion

Sarcopenia prevalence is high (27%) in COPD patients. In addition, these patients had worse pulmonary function and activity tolerance compared to patients without sarcopenia.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=367422, identifier CRD42022367422.

Resistance training of peripheral muscles benefits respiratory parameters in older women with sarcopenia: Randomized controlled trial

PURPOSE OF THE RESEARCH

Ageing entails a decrease in muscle mass and strength, known as sarcopenia, which also affects respiratory function. Physical exercise is an appropriate intervention to treat both conditions. This study aims to assess the efficacy of high-intensity resistance training (HIRT) on clinical parameters of respiratory function and health-related quality of life (QoL) in community-dwelling older women with sarcopenia.

METHODS

Fifty-one sarcopenic community-dwelling women aged 70 years and older were randomized to either six months of HIRT (n = 24) or control (n = 27). At baseline and post-intervention, participants were assessed for skeletal-muscle sarcopenia; respiratory sarcopenia status; respiratory function: spirometry (FEV₁, FVC, FEV₁/FVC, and FEF_25-75) and expiratory (MEP) and inspiratory (MIP) respiratory muscle strength parameters; and health-related QoL (EURO-QOL 5D-3 L).

RESULTS

A group-by-time interaction effect for MEP (p = 0.044, Ƞ²=0.108) was observed. CG showed a significant decrease in FEV₁ (mean difference [MD] -0.12 L; 95% confidence interval [CI] -0.20, -0.05; p = 0.002); and FVC (MD -0.18 L; 95% CI -0.33, -0.03; p = 0.024) after six months, whereas the HIRT maintained respiratory function without change. Post-intervention, mean EQ-VAS increased in the HIRT and decreased in CG, resulting in a significant between-group difference (mean 73.0 standard deviation [SD] 16.99 vs 61.1 SD 18.2 points, respectively; p = 0.044). Respiratory sarcopenia status was reverted in the HIRT.

CONCLUSIONS

HIRT increased muscle strength and halted age-related respiratory function decline in sarcopenic old women. A strength intervention could benefit health-related QoL and physical well-being. REGISTERED IN CLINICALTRIALS.GOV: NCT03834558.

Reduced Skeletal Muscle Mass Is Associated with an Increased Risk of Asthma Control and Exacerbation

BACKGROUND

Skeletal muscle mass (SMM) has been suggested to be associated with multiple health-related outcomes. However, the potential influence of SMM on asthma has not been largely explored.

OBJECTIVE

To study the association between SMM and clinical features of asthma, including asthma control and exacerbation, and to construct a model based on SMM to predict the risk of asthma exacerbation (AEx).

METHODS

In this prospective cohort study, we consecutively recruited patients with asthma (n = 334), classified as the SMM ^Normal group (n = 223), SMM ^Low group (n = 88), and SMM ^High group (n = 23). We investigated the association between SMM and clinical asthma characteristics and explored the association between SMM and asthma control and AEx within a 12-month follow-up period. Based on SMM, an exacerbation prediction model was developed, and the overall performance was externally validated in an independent cohort (n = 157).

RESULTS

Compared with the SMM ^Normal group, SMM ^Low group exhibited more airway obstruction and worse asthma control, while SMM ^High group had a reduced eosinophil percentage in induced sputum. Furthermore, SMM ^Low group was at a significantly increased risk of moderate-to-severe exacerbation compared with the SMM ^Normal group (relative risk _adjusted 2.02 [95% confidence interval (CI), 1.35-2.68]; p = 0.002). In addition, a model involving SMM was developed which predicted AEx (area under the curve: 0.750, 95% CI: 0.691-0.810).

CONCLUSIONS

Low SMM was an independent risk factor for future AEx. Furthermore, a model involving SMM for predicting the risk of AEx in patients with asthma indicated that assessment of SMM has potential clinical implications for asthma management.

Nutrition in the prevention and management of sarcopenia - A special focus on Asian Indians

Sarcopenia, characterized by loss of muscle mass and strength, is common in advanced old age but can be accelerated by chronic disease, malnutrition and physical inactivity. Early initiation of intervention to achieve and maintain a higher peak muscle mass and strength may allow for prevention or delay of sarcopenia and facilitate independent living even in old age. In this context, malnutrition, a significant contributor to sarcopenia, is often overlooked among the Indian population. Maintenance of an optimal energy and protein balance with adequate physical activity level is essential to preserve physical function in the aging population. However, research on the role of micronutrients in muscle maintenance, is still in its infancy. This narrative review, therefore, aims to explore the current status of International and Indian research on the role of nutrition in sarcopenia mitigation and the way forward.

Increased chest CT derived bone and muscle measures capture markers of improved morbidity and mortality in COPD

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a disease of accelerated aging and is associated with comorbid conditions including osteoporosis and sarcopenia. These extrapulmonary conditions are highly prevalent yet frequently underdiagnosed and overlooked by pulmonologists in COPD treatment and management. There is evidence supporting a role for bone-muscle crosstalk which may compound osteoporosis and sarcopenia risk in COPD. Chest CT is commonly utilized in COPD management, and we evaluated its utility to identify low bone mineral density (BMD) and reduced pectoralis muscle area (PMA) as surrogates for osteoporosis and sarcopenia. We then tested whether BMD and PMA were associated with morbidity and mortality in COPD.

METHODS

BMD and PMA were analyzed from chest CT scans of 8468 COPDGene participants with COPD and controls (smoking and non-smoking). Multivariable regression models tested the relationship of BMD and PMA with measures of function (6-min walk distance (6MWD), handgrip strength) and disease severity (percent emphysema and lung function). Multivariable Cox proportional hazards models were used to evaluate the relationship between sex-specific quartiles of BMD and/or PMA derived from non-smoking controls with all-cause mortality.

RESULTS

COPD subjects had significantly lower BMD and PMA compared with controls. Higher BMD and PMA were associated with increased physical function and less disease severity. Participants with the highest BMD and PMA quartiles had a significantly reduced mortality risk (36% and 46%) compared to the lowest quartiles.

CONCLUSIONS

These findings highlight the potential for CT-derived BMD and PMA to characterize osteoporosis and sarcopenia using equipment available in the pulmonary setting.

Osteosarcopenia in Patients with Chronic Obstructive Pulmonary Diseases: Which Pathophysiologic Implications for Rehabilitation?

Chronic obstructive pulmonary disease (COPD) is a burdensome condition affecting a growing number of people worldwide, frequently related to major comorbidities and functional impairment. In these patients, several factors might have a role in promoting both bone and muscle loss, including systemic inflammation, corticosteroid therapies, sedentary behaviours, deconditioning, malnutrition, smoking habits, and alcohol consumption. On the other hand, bone and muscle tissues share several linkages from functional, embryological, and biochemical points of view. Osteosarcopenia has been recently defined by the coexistence of osteoporosis and sarcopenia, but the precise mechanisms underpinning osteosarcopenia in patients with COPD are still unknown. In this scenario, a deeper understanding of the molecular basis of osteosarcopenia might guide clinicians in a personalized approach integrating skeletal muscle health with the pulmonary rehabilitation framework in COPD. Taken together, our results summarized the currently available evidence about the multilevel interactions between osteosarcopenia and COPD to pave the way for a comprehensive approach targeting the most common risk factors of these pathological conditions. Further studies are needed to clarify the role of modern clinical strategies and telemedicine solutions to optimize healthcare delivery in patients with COPD, including osteopenia, osteoporosis, and sarcopenia screening in these subjects.

Ultrasound Assessment of the Rectus Femoris in Patients with Chronic Obstructive Pulmonary Disease Predicts Sarcopenia

PURPOSE

Sarcopenia, an age-related loss of skeletal muscle mass and function, is frequent in patients with chronic obstructive pulmonary disease (COPD) and is linked to a poor prognosis. The diagnosis of sarcopenia requires specific equipment and is inconvenient to introduce into clinical practice. Ultrasound is an innovative method to assess muscle quantity. The objective of this research was to evaluate the use of ultrasound for prospectively screening for sarcopenia in COPD patients.

PATIENTS AND METHODS

A total of 235 stable patients with COPD were included in this observational study and divided into development and validation sets. The Asian Working Group for Sarcopenia standards were used to define sarcopenia. The thickness (RF_thick) and cross-sectional area (RF_csa) of the rectus femoris were measured using ultrasound. Receiver operating characteristic curve analysis of RF_thick and RF_csa was used to predict sarcopenia. Nomogram models were constructed based on RF_thick, RF_csa, age and body mass index to identify sarcopenia.

RESULTS

Sarcopenia was present in 83 (35.32%) patients. Patients with sarcopenia had advanced age, decreased pulmonary function, decreased physical function and poor clinical outcomes. RF_thick and RF_csa showed good predictive ability for sarcopenia in the development and validation sets. The nomogram based on RF_thick and RF_csa could detect sarcopenia in COPD patients, and all had significant predictive performance in the development and validation sets. The calibration plot showed good agreement between the nomogram predictions and actual observations.

CONCLUSION

The ultrasound measurement of the rectus femoris has potential for the clinical assessment of sarcopenia in patients with COPD.

Muscle function and functional performance after pulmonary rehabilitation in patients with chronic obstructive pulmonary disease: a prospective observational study

This study aimed to measure changes in different properties of skeletal muscles and evaluate their contribution and relationship to changes in functional performance after pulmonary rehabilitation (PR) in patients with chronic obstructive pulmonary disease (COPD). COPD outpatients attending 5 weeks of conventional PR were recruited. Functional performance [5-repetitions sit-to-stand (5STS), and 4-m gait speed (4mGS)], and muscle function (maximal isometric strength, power, force control, and relative concentric and eccentric activation during 5STS) were assessed after PR and 3 months of follow-up. Twenty patients (71 years; 52% of predicted FEV₁) completed the study. 4mGS and relative concentric activation during 5STS decreased respectively by 7.7% and 26% between the beginning of PR and follow-up. Quadriceps strength, power, and force control improved by 10.4%, 27.3%, and 15.2%, respectively, from the beginning of PR to follow-up the relative eccentric activation during 5STS explained 31% of the variance in 4mGS changes. In conclusion, functional performance appeared to decline after conventional PR, whereas several properties of skeletal muscles were maintained at follow-up in COPD outpatients. Of note, eccentric contractions might play a role in the improvement of functional performance. Therefore, future studies with interventional design should include eccentric training in PR programs during clinical COPD practice.

Recent advances in vitamin D implications in chronic respiratory diseases

Chronic airway inflammatory and infectious respiratory diseases are the most common medical respiratory conditions, associated with significant morbidity and mortality. Vitamin D (1,25(OH)₂D₃) deficiency has been shown to be highly prevalent in patients with chronic airway inflammatory and infectious diseases, correlated with increased disease severity. It has been established that vitamin D modulates ongoing abnormal immune responses in chronic respiratory diseases and is shown to restrict bacterial and viral colonization into the lungs. On the contrary, other studies revealed controversy findings regarding vitamin D efficacy in respiratory diseases. This review aims to update the current evidence regarding the role of vitamin D in airway inflammation and in various respiratory diseases. A comprehensive search of the last five years of literature was conducted using MEDLINE and non-MEDLINE PubMed databases, Ovid MEDLINE, SCOPUS-Elsevier, and data from in vitro and in vivo experiments, including clinical studies. This review highlights the importance of understanding the full range of implications that vitamin D may have on lung inflammation, infection, and disease severity in the context of chronic respiratory diseases.

Quantitative computed tomography-based evaluation of skeletal muscle and presence of sarcopenia in patients with chronic obstructive pulmonary disease

Sarcopenia, or age-related muscle loss, is a common comorbidity in patients with chronic obstructive pulmonary disease (COPD) with multiple contributing factors. We hypothesized that the presence of sarcopenia can be estimated using quantitative computed tomography-based parameters in patients with COPD. We retrospectively evaluated 38 elderly (≥65 years) men with COPD for pooled data, including hand grip strength and gait speed. Sarcopenia was diagnosed based on the updated 2019 criteria set by the Asian Working Group for Sarcopenia. Cross-sectional area of the erector spinae muscle (ESM) and pectoralis muscle (PM) were quantitatively evaluated and adjusted by height (ESM-I, and PM-I). Sarcopenia was diagnosed in 11 (29%) patients. The mean ESM-I and PM-I were 11.0 and 9.5 cm²/m², respectively, and significantly correlated with height-adjusted appendicular skeletal muscle mass. The optimal cutoff ESM-I for the presence of sarcopenia was 9.41 cm²/m². ESM loss helped estimate sarcopenia in patients with COPD.

Myostatin/HIF2α-Mediated Ferroptosis is Involved in Skeletal Muscle Dysfunction in Chronic Obstructive Pulmonary Disease

Objective

Methods

Results

Conclusion