Are oxidative stress biomarkers and respiratory muscles strength associated with COPD-related sarcopenia in older adults?

Quercetin prevents sarcopenia by reversing oxidative stress and mitochondrial damage

This study investigates the effectiveness of quercetin (QUE) in preventing sarcopenia via the PI3K/AKT signaling pathway. Thirty SD rats were categorized into three groups: a young control group (Y), an old control group (O), and an old QUE-supplemented group (O + QUE). Body weight and grip strength were monitored weekly during the experiment. Soleus and gastrocnemius muscle weights, gastrocnemius tissue pathological examination, cell apoptosis, and mitochondrial damage were evaluated using HE, TUNEL staining, electron microscopy, and JC-1 staining. Biochemical assays and molecular biology techniques (qPCR and Western blot) were used to assess oxidative stress markers and the expression of sarcopenia-related genes and proteins. QUE supplementation increased muscle weight and improved grip strength in aged rats. Furthermore, QUE supplementation alleviated tissue damage, apoptosis, enhanced antioxidant capacity, and decreased damage to oxidative stress and mitochondria in the gastrocnemius of old rats. Molecular assessments revealed downregulation of muscle degradation markers (MuRF1, Atrogen-1, Bnip3) and upregulation of PI3K/AKT pathway proteins, suggesting a mechanistic pathway through which QUE mitigates sarcopenia. QUE maybe modulate the PI3K/AKT pathway to alleviate oxidative stress, mitochondrial damage, and muscle degradation due to aging, highlighting its potential as a therapeutic agent against sarcopenia.

The value of inspiratory muscle training on poststroke sarcopenia and its effect on rehabilitation outcomes: A randomized controlled trial

Objectives

The purpose of the study was to validate the effectiveness of inspiratory muscle training (IMT) in preventing poststroke sarcopenia and to examine the impact of IMT on the prognosis for stroke recovery.

Patients and methods

In the randomized controlled trial, 367 patients with a first stroke event between December 2021 and May 2023 were randomly allocated to an experimental group and a control group. Of the patients, 329 (179 males, 150 females; mean age: 61.0±8.7 years; range, 35 to 78 years) completed the experiment and were included in the analyses (experimental group, n=164; control group, n=165). Both groups received conventional neurological rehabilitation treatment, and the experimental group also received IMT. The incidence of poststroke sarcopenia and pneumonia during four weeks of treatment were examined and compared. Additionally, an analysis was conducted on the variations between the two groups in maximal inspiratory pressure (MIP), modified Rankin scale (mRS), trunk impact scale (TIS), and modified Barthel index (MBI).

Results

Following four weeks of therapy, the experimental group experienced a reduced incidence of poststroke sarcopenia (p=0.004) and pneumonia (p=0.017) than the control group. The trial group performed better than the control group in MBI (p=0.002), TIS (p<0.001), MIP (p<0.001), and mRS (p=0.011) scores after intervention.

Conclusion

In conclusion, the findings demonstrate that early IMT can significantly lower the risk of poststroke sarcopenia and pneumonia while also improving the prognosis for stroke patients' recovery.

New Insight in Using of Mesenchyme Stem Cell Conditioning Medium for the Impaired Muscle related Biomarkers: In vivo Study with Rat Model

AIMS AND OBJECTIVES

This study aimed to investigate the effects of Umbilical Cord Mesencymal Stem Cell Conditioning Medium (UC MSC-CM) administration on body weight recovery and the level of four molecular biomarkers, namely Superoxide Dismutase (SOD), vascular Endothelial Growth Factor (VEGF), C-Reactive Protein (CRP), and myostatin.

MATERIALS AND METHODS

Secretome was injected intramuscularly twice at 1.5 mL (day 7 and 14) into the right thigh of high-dose, short-term galactose-induced aging rats. The data of day 7 (before) and day 21 (after the administration) were evaluated. The body weights and the four biomarkers were measured before (day 7) and after intervention (day 21).

RESULTS

This study showed that the UC MSC-CM intramuscular administrations did not influence body weight regeneration. However, it could increase SOD and VEGF levels and decrease CRP and myostatin levels.

CONCLUSION

Treatment with UC MSC-CM is a promising and potential agent in treating sarcopenia.

Risk Factors of Sarcopenia in COPD Patients: A Meta-Analysis

Objective

Sarcopenia is a common complication of COPD associated with an age-related reduction in skeletal muscle mass associated with decreased muscle strength and / or reduced mobility. The incidence of sarcopenia in patients with COPD is twice that of non-COPD patients and is associated with poor prognosis, this study aimed to investigate the influencing factors of sarcopenia in COPD patients.

Methods

Selected studies from PubMed, Embase, Web of Science, Cochrane Library, Wanfang, Wanfang, CNKI, CBM, and Wanfang databases as of November 12023. Patients aged 18 were selected; data were then independently extracted by two reviewers using a standard data collection form.

Results

In total, 17 articles reporting on 5408 patients were included. Age (OR = 1.083; 95% CI, 1.024-1.145), ALB (OR = 0.752; 95% CI, 0.724-0.780), BMI(OR = 0.701; 95% CI, 0.586-0.838), smoking (OR = 1.859; 95% CI, 1.037-3.334), diabetes (OR = 1.361; 95% CI, 1.095-1.692), qi deficiency (OR = 9.883; 95% CI, 2.052, 47.593), GOLD C (OR =2.232; 95% CI, 1.866, 2.670) and GOLD D (OR = 2.195; 95% CI, 1.826-2.637) were factors affecting muscle loss in COPD patients.

Conclusion

Sarcopenia is more prevalent in patients with COPD. Age, body mass index, smoking, diabetes mellitus, qi deficiency, ALB, and GOLD grade were the contributing factors for sarcopenia in patients with chronic obstructive pulmonary disease. In the future, medical staff should not only pay attention to the early screening of sarcopenia in high-risk groups, but also provide relevant prevention information.

Proposal and validation of a new approach in tele-rehabilitation with 3D human posture estimation: a randomized controlled trial in older individuals with sarcopenia

OBJECTIVE

Through a randomized controlled trial on older adults with sarcopenia, this study compared the training effects of an AI-based remote training group using deep learning-based 3D human pose estimation technology with those of a face-to-face traditional training group and a general remote training group.

METHODS

Seventy five older adults with sarcopenia aged 60-75 from community organizations in Changchun city were randomly divided into a face-to-face traditional training group (TRHG), a general remote training group (GTHG), and an AI-based remote training group (AITHG). All groups underwent a 3-month program consisting of 24-form Taichi exercises, with a frequency of 3 sessions per week and each session lasting 40 min. The participants underwent Appendicular Skeletal Muscle Mass Index (ASMI), grip strength, 6-meter walking pace, Timed Up and Go test (TUGT), and quality of life score (QoL) tests before the experiment, during the mid-term, and after the experiment. This study used SPSS26.0 software to perform one-way ANOVA and repeated measures ANOVA tests to compare the differences among the three groups. A significance level of p < 0.05 was defined as having significant difference, while p < 0.01 was defined as having a highly significant difference.

RESULTS

(1) The comparison between the mid-term and pre-term indicators showed that TRHG experienced significant improvements in ASMI, 6-meter walking pace, and QoL (p < 0.01), and a significant improvement in TUGT timing test (p < 0.05); GTHG experienced extremely significant improvements in 6-meter walking pace and QoL (p < 0.01); AITHG experienced extremely significant improvements in ASMI, 6-meter walking pace, and QoL (p < 0.01), and a significant improvement in TUGT timing test (p < 0.05). (2) The comparison between the post-term and pre-term indicators showed that TRHG experienced extremely significant improvements in TUGT timing test (p < 0.01); GTHG experienced significant improvements in ASMI and TUGT timing test (p < 0.05); and AITHG experienced extremely significant improvements in TUGT timing test (p < 0.01). (3) During the mid-term, there was no significant difference among the groups in all tests (p > 0.05). The same was in post-term tests (p > 0.05).

CONCLUSION

Compared to the pre-experiment, there was no significant difference at the post- experiment in the recovery effects on the muscle quality, physical activity ability, and life quality of patients with sarcopenia between the AI-based remote training group and the face-to-face traditional training group. 3D pose estimation is equally as effective as traditional rehabilitation methods in enhancing muscle quality, functionality and life quality in older adults with sarcopenia.

TRIAL REGISTRATION

The trial was registered in ClinicalTrials.gov (NCT05767710).

Association of the oxidative balance score with sarcopenia among young and middle-aged adults: findings from NHANES 2011-2018

Background

Sarcopenia is associated with oxidative stress. The Oxidative Balance Score (OBS) is commonly used to assess dietary and lifestyle exposure to oxidative stress. However, few studies in the literature have assessed the correlation between sarcopenia and OBS.

Aim

This study aimed to assess the association between OBS and sarcopenia among young and middle-aged adults in the United States using data from the National Health and Nutrition Examination Survey (NHANES).

Method

Weighted logistic regression analysis was used to investigate the association between OBS and sarcopenia based on data from NHANES 2011-2018. Subgroup analyses were performed to observe the consistency of the outcomes, and the stability of the results was tested using sensitivity analyses.

Result

The final sample included 5,525 young and middle-aged American adults. A higher OBS was associated with a lower risk of sarcopenia. In the fully adjusted model, the second (odds ratio [OR]: 0.62, 95% confidence interval [CI]: 0.41, 0.94; p = 0.023), third (OR: 0.50; 95% CI: 0.34, 0.74; p < 0.001), and highest quartiles (OR: 0.18; 95% CI: 0.11, 0.28; p < 0.001) of the OBS were associated with higher risks of sarcopenia when compared to the lowest quartile. This association was consistent across both dietary and lifestyle OBS scores. Our subgroup analysis revealed no significant differences between the subgroups of variables included in the interaction analysis. Sensitivity analyses revealed similar results.

Conclusion

Our study showed that higher antioxidant and lower antioxidant exposure may decrease the risk of developing sarcopenia. Higher OBS scores may indicate greater protection against sarcopenia; however, further clinical studies are warranted to confirm these findings.

Prediction model and assessment of malnutrition in patients with stable chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) combined with malnutrition results in decreased exercise capacity and a worse quality of life. We aimed to develop an observational case-control study to explore the effective and convenient method to identify potential individuals is lacking. This study included data from 251 patients with COPD and 85 participants in the control group. Parameters and body composition were compared between groups, and among patients with varied severity. The LASSO approach was employed to select the features for fitting a logistic model to predict the risk of malnutrition in patients with stable COPD. Patients with COPD exhibited significantly lower 6-min walk distance (6MWD), handgrip strength, fat-free mass index (FFMI), skeletal muscle mass (SMM) and protein. The significant predictors identified following LASSO selection included 6MWD, waist-to-hip ratio (WHR), GOLD grades, the COPD Assessment Test (CAT) score, and the prevalence of acute exacerbations. The risk score model yielded good accuracy (C-index, 0.866 [95% CI 0.824-0.909]) and calibration (Brier score = 0.150). After internal validation, the adjusted C-index and Brier score were 0.849, and 0.165, respectively. This model may provide primary physicians with a simple scoring system to identify malnourished patients with COPD and develop appropriate rehabilitation interventions.

Association between handgrip strength and small airway disease in patients with stable chronic obstructive pulmonary disease

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is associated with airflow limitation resulting from a combination of small airway disease (SAD) and parenchymal destruction. Although various diagnostic methods for SAD exist, access to these tools can be limited.

OBJECTIVES

This study aimed to explore the correlation between handgrip strength (HGS) and SAD in COPD patients.

DESIGN

Cross-sectional prospective study.

METHODS

HGS was measured using a hand dynamometer. SAD was evaluated using impulse oscillometry, with results reported as the difference between respiratory resistance at 5 and 20 Hz (R5-R20). SAD was defined as R5-R20 ⩾0.07 kPa/L/s. The receiver operator characteristic (ROC) curves, sensitivity, and specificity values were calculated to determine the optimal cutoff value of HGS for predicting SAD.

RESULTS

Sixty-four patients (90.6% male) were included. The average age was 72.1 ± 8.3 years, and body mass index was 23.4 ± 4.2 kg/m2. FEV1 was 71.6 ± 21.3%, and HGS was 30.2 ± 8.1 kg. R5-R20 was 0.11 ± 0.08 kPa/L/s. SAD was found in 64.1% of patients. A negative correlation between HGS and R5-R20 was observed (r = -0.332, p = 0.007). The best cutoff value for HGS in detecting SAD was determined to be 28.25 kg, with a sensitivity of 73.9%, specificity of 65.9%, and an area under ROC curve of 0.685 (95% CI 0.550-0.819, p = 0.015).

CONCLUSION

SAD is common in COPD patients, and HGS is significantly negatively correlated with SAD. This tool might serve as an alternative or adjunctive assessment for small airway dysfunction in COPD patients.

REGISTRATION

This study was registered with ClinicalTrials.gov with number NCT06223139.

Glycyl- l-histidyl- l-lysine-Cu2+ rescues cigarette smoking-induced skeletal muscle dysfunction via a sirtuin 1-dependent pathway

BACKGROUND

Skeletal muscle dysfunction is an important co-morbidity in patients with chronic obstructive pulmonary disease (COPD) and is significantly associated with increased mortality. Oxidative stress has been demonstrated an important trigger for COPD-related skeletal muscle dysfunction. Glycine-histidine-lysine (GHK) is an active tripeptide, which is a normal component of human plasma, saliva, and urine; promotes tissue regeneration; and acts as an anti-inflammatory and antioxidant properties. The purpose of this study was to determine whether GHK is involved in COPD-related skeletal muscle dysfunction.

METHODS

The plasma GHK level in patients with COPD (n = 9) and age-paired healthy subjects (n = 11) were detected using reversed-phase high-performance liquid chromatography. The complex GHK with Cu (GHK-Cu) was used in in vitro (C2C12 myotubes) and in vivo experiments (cigarette smoking [CS]-exposure mouse model) to explore the involvement of GHK in CS-induced skeletal muscle dysfunction.

RESULTS

Compared with healthy control, plasma GHK levels were decreased in patients with COPD (70.27 ± 38.87 ng/mL vs. 133.0 ± 54.54 ng/mL, P = 0.009). And plasma GHK levels in patients with COPD were associated with pectoralis muscle area (R = 0.684, P = 0.042), inflammatory factor TNF-α (R = -0.696, P = 0.037), and antioxidative stress factor SOD2 (R = 0.721, P = 0.029). GHK-Cu was found to rescue CSE-induced skeletal muscle dysfunction in C2C12 myotubes, as evidenced by increased expression of myosin heavy chain, reduced expression of MuRF1 and atrogin-1, elevated mitochondrial content, and enhanced resistance to oxidative stress. In CS-induced muscle dysfunction C57BL/6 mice, GHK-Cu treatment (0.2 and 2 mg/kg) reduces CS-induced muscle mass loss (skeletal muscle weight (1.19 ± 0.09% vs. 1.29 ± 0.06%, 1.40 ± 0.05%; P < 0.05) and muscle cross-sectional area elevated (1055 ± 552.4 μm² vs. 1797 ± 620.9 μm² , 2252 ± 534.0 μm² ; P < 0.001), and also rescues CS-induced muscle weakness, indicated by improved grip strength (175.5 ± 36.15 g vs. 257.6 ± 37.98 g, 339.1 ± 72.22 g; P < 0.01). Mechanistically, GHK-Cu directly binds and activates SIRT1(the binding energy was -6.1 kcal/mol). Through activating SIRT1 deacetylation, GHK-Cu inhibits FoxO3a transcriptional activity to reduce protein degradation, deacetylates Nrf2 and contribute to its action of reducing oxidative stress by generation of anti-oxidant enzymes, increases PGC-1α expression to promote mitochondrial function. Finally, GHK-Cu could protect mice against CS-induced skeletal muscle dysfunction via SIRT1.

CONCLUSIONS

Plasma glycyl- l-histidyl- l-lysine level in patients with chronic obstructive pulmonary disease was significantly decreased and was significantly associated with skeletal muscle mass. Exogenous administration of glycyl- l-histidyl- l-lysine-Cu²⁺ could protect against cigarette smoking-induced skeletal muscle dysfunction via sirtuin 1.

Biochemical Markers of Musculoskeletal Health and Aging to be Assessed in Clinical Trials of Drugs Aiming at the Treatment of Sarcopenia: Consensus Paper from an Expert Group Meeting Organized by the European Society for Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases (ESCEO) and the Centre Académique de Recherche et d'Expérimentation en Santé (CARES SPRL), Under the Auspices of the World Health Organization Collaborating Center for the Epidemiology of Musculoskeletal Conditions and Aging

In clinical trials, biochemical markers provide useful information on the drug's mode of action, therapeutic response and side effect monitoring and can act as surrogate endpoints. In pharmacological intervention development for sarcopenia management, there is an urgent need to identify biomarkers to measure in clinical trials and that could be used in the future in clinical practice. The objective of the current consensus paper is to provide a clear list of biochemical markers of musculoskeletal health and aging that can be recommended to be measured in Phase II and Phase III clinical trials evaluating new chemical entities for sarcopenia treatment. A working group of the European Society for Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases (ESCEO) proposed classifying biochemical markers into 2 series: biochemical markers evaluating musculoskeletal status and biochemical markers evaluating causal factors. For series 1, the group agreed on 4 biochemical markers that should be assessed in Phase II or Phase III trials (i.e., Myostatin-Follistatin, Brain Derived Neurotrophic Factor, N-terminal Type III Procollagen and Serum Creatinine to Serum Cystatin C Ratio - or the Sarcopenia Index). For series 2, the group agreed on 6 biochemical markers that should be assessed in Phase II trials (i.e., the hormones insulin-like growth factor-1 (IGF-I), dehydroepiandrosterone sulphate, and cortisol, and the inflammatory markers C-reactive protein (CRP), interleukin-6 and tumor necrosis factor-α), and 2 in Phase III trials (i.e., IGF-I and CRP). The group also proposed optional biochemical markers that may provide insights into the mode of action of pharmacological therapies. Further research and development of new methods for biochemical marker assays may lead to the evolution of these recommendations.

High blood urea nitrogen to creatinine ratio is associated with increased risk of sarcopenia in patients with chronic obstructive pulmonary disease

BACKGROUND AND AIMS

Sarcopenia has been reported to be a prognostic factor for chronic obstructive pulmonary disease (COPD). However, the relationship between the ratio of blood urea nitrogen to creatinine (BUN/Cr) and sarcopenia in patients with COPD remain unclear. Therefore, the purpose of this study is to explore whether the ratio can be used as a predictor of sarcopenia in hospitalized COPD patients.

METHODS

The skeletal muscle area index (SMI) at the level of the 12th thoracic vertebra (T12) was used to assess the risk of sarcopenia in patients. This single center cross-sectional study was conducted by analyzing the clinical parameters and identifying the T12 skeletal muscle area (SMA) and density (SMD) on chest CT images of COPD hospitalized patients admitted to the respiratory department of our hospital from March 2018 to August 2021. The study enrolled 265 hospitalized patients. Based on the different statistical properties of the above variables, differences between groups were measured by independent sample Student t-tests, Mann-Whitney U tests, or Chi-Square tests. Multivariable linear regression analysis was used to evaluate the relationship between the value of BUN/Cr and the risk of sarcopenia.

RESULTS

The serum BUN/Cr ratio was negatively correlated with SMI (r = -0.201, p = 0.001) in COPD patients, and multivariate linear regression analysis showed that this ratio was associated with the risk of sarcopenia (β = -0.109, p = 0.041). The optimal cut-off value of BUN/Cr ratio for identifying COPD patients with sarcopenia was 97.893. There was also a significant negative correlation between serum BUN/Cr ratio and forced vital capacity (FVC; r = -0.235, p < 0.001) and forced expiratory volume in the first second (FEV1; r = -0.219, p < 0.001).

CONCLUSION

The BUN/Cr ratio can be used to predict sarcopenia and evaluate pulmonary function in hospitalized COPD patients.

Effects of Muscle Energy Technique and Joint Manipulation on Pulmonary Functions, Mobility, Disease Exacerbations, and Health-Related Quality of Life in Chronic Obstructive Pulmonary Disease Patients: A Quasiexperimental Study

Chronic obstructive pulmonary disease (COPD) is primarily a disease of the lungs; however, extrapulmonary comorbidities like rib cage stiffness, decreased thoracic spine mobility, postural changes, and skeletal muscle dysfunctions also coexist. Muscle energy technique (MET) and joint manipulation (JM) may help alleviate these musculoskeletal problems. This study was aimed at evaluating the effectiveness of MET and JM on pulmonary functions, dyspnea, chest wall mobility, disease exacerbations, and health-related quality of life in COPD patients. A total of 16 patients (7 women and 9 men) suffering from COPD between the ages of 35 and 65 years participated in the study. Pretest-posttest quasiexperimental design was used. MET was applied to the sternocleidomastoid, anterior scalene, pectoralis major muscles, and at the C4-C6 level of the cervical spine. Maitland JM was performed in the thoracic region at the intervertebral, costovertebral, and costotransverse joints. The treatment intervention lasted for 3 weeks. FEV1/FVC, maximum inspiratory pressure (MIP), SpO2, modified Borg dyspnea scale (MBDS), COPD assessment test (CAT), mMRC dyspnea scale, BODE index, right and left hemidiaphragm excursion, and chest wall expansion at T4 and T10 levels were the outcome measures. Significant improvement ( $p<0.05$ ) was observed in FEV1/FVC, MIP, SpO2, MBDS, CAT, mMRC dyspnea scale, BODE index, and chest expansion at T4 and T10 levels. Only for the hemidiaphragm excursion, no significant ( $p>0.05$ ) improvement was observed. Combined application of MET to accessory respiratory muscles and cervical spine and JM to thoracic spine improved pulmonary functions, chest wall mobility, and health-related quality of life and reduced dyspnea and disease exacerbations in patients with mild to moderate COPD.

Resistin as a Systemic Inflammation-Related Biomarker for Sarcopenia in Patients With Chronic Obstructive Pulmonary Disease

Background

Sarcopenia is common in patients with chronic obstructive pulmonary disease (COPD) and is mainly caused by systemic inflammation. Resistin acts as a proinflammatory cytokine and is involved in the activation of multiple inflammatory signaling pathways. The aim of this study was to determine the relationship between resistin levels and systemic inflammation and to assess the clinical value of circulating resistin for sarcopenia in patients with COPD.

Methods

In this prospective observational study, we enrolled 235 patients with COPD who were divided into development and validation sets. The definition of sarcopenia followed the guidelines from the Asian Working Group for Sarcopenia. Serum concentrations of resistin and TNF-α were measured using an enzyme-linked immunosorbent assay (ELISA).

Results

In this study, higher serum resistin levels were significantly associated with lower skeletal muscle mass and muscular strength. The serum resistin levels in patients with sarcopenia were significantly higher than those in patients without sarcopenia. The serum resistin level had positive correlations with the serum TNF-α level (r = 0.250, p = 0.007). The predictive efficacy of the serum resistin level (AUC: 0.828) for sarcopenia was superior to that of the serum TNF-α level (AUC: 0.621). The cutoff point (7.138 ng/ml) for the serum resistin level was validated in the validation set (AUC: 0.818).

Conclusions

Serum resistin levels were associated with systemic inflammation and can be used accurately and easily to predict sarcopenia in patients with COPD.

Efficacy of Acupuncture on Quality of Life, Functional Performance, Dyspnea, and Pulmonary Function in Patients with Chronic Obstructive Pulmonary Disease: Protocol for a Randomized Clinical Trial

Chronic obstructive pulmonary disease (COPD) is a respiratory disease characterized by the presence of chronic airflow obstruction. Previous studies have evaluated the effect of acupuncture treatment (AT) in patients with COPD. Nevertheless, these studies show a great deal of heterogeneity in treatment protocols, having sample sizes that are too small to estimate and clarify effect size and heterogeneity in patients’ baseline. The aim of this study is to evaluate the effectiveness of acupuncture on quality of life, functional performance, dyspnea, and pulmonary function in patients with COPD. As such, patients will go through the following three phases: Phase I–pretreatment: period of subject selection and inclusion in the protocol, with an interview and performance of exams and tests as follows: Mini-Cog, dual-energy X-ray absorptiometry, spirometry, the Patient-Generated Index, Saint George’s Respiratory Questionnaire, the six-minute walk test, the London Chest Activity of Daily Living, and the COPD Assessment Test. Phase II–8 weeks of treatment, with AT 3 times a week, with two parallel groups: Group I–with 50 subjects–AT according to the recommended technical standards; Group II–with 50 subjects–Control, without acupuncture. Phase III–Continuation of AT for 8 weeks, maintaining the subjects in the previously allocated groups and following the same methodology.

Plasma levels of myokines and inflammatory markers are related with functional and respiratory performance in older adults with COPD and sarcopenia

This study investigated whether blood-based biomarkers were related to functional test performance and respiratory muscle strength in older adults with COPD and sarcopenia. The participants included in this cross-sectional study were from both sexes and sixty years or older. Based on clinical assessment, participants were categorized in COPD (n = 43) and non-COPD (NCOPD) (n = 43) groups. They were also assessed for body composition and muscular mass by dual-energy X-ray absorptiometry, using the relative skeletal muscle index for the diagnosis of sarcopenia. A series of functional tests, including short physical performance battery (SPPB), 6-minute walking test (6MWT), maximal inspiratory and expiratory pressures (MIP and MEP), were carried out. Plasma levels of myokines (Irisin and BDNF), and soluble TNF receptors (sTNFR1 and sTNFR2) were determined by ELISA. In the multivariate analysis, 6MWD was associated with age, COPD-related sarcopenia and BDNF (R² = 0.29; f² = 0.41). SPPB score was associated with COPD-related sarcopenia and sTNFR1 (R² = 0.25; f² = 0.33). MIP value was associated with sex, COPD-related sarcopenia, sTNFR2 and Irisin (R² = 0.24; f² = 0.31). Finally, MEP value was associated with sex COPD-related sarcopenia (R² = 0.18; f² = 0.22). Plasma levels of myokines and inflammatory markers are related with functional and respiratory performance in older adults with COPD and sarcopenia.