Inflammatory markers are associated with ventilatory limitation and muscle dysfunction in obstructive lung disease in well functioning elderly subjects

The Mediation of Circulating Inflammatory Proteins in the Causal Pathway from Immune Cells to COPD

Objective

Observational studies have indicated that immune cells and circulating inflammatory proteins may play a dual role in the progression of COPD; however, the precise mechanisms remain uncertain. The objective of this study was to ascertain the causal relationship between immune cells and COPD and to quantify the potential role of circulating inflammatory proteins as mediators.

Methods

A two-sample Mendelian randomisation analysis was conducted involving 731 immune cells, 91 inflammatory proteins and COPD, utilising summary-level data from genome-wide association studies. The causal relationships between immune cells, inflammatory proteins and COPD were sequentially analysed by multivariate Mendelian randomisation and validated using Bayesian weighted Mendelian randomisation. Subsequently, sensitivity analyses were conducted, employing Cochran's Q test to assess heterogeneity, MR-PRESSO and MR-Egger tests to assess pleiotropy, and reverse MR and Steiger directionality tests to rule out reverse causality. Lastly, a two-step approach was employed to ascertain the proportion of inflammatory proteins that mediate immune cell-mediated effects in COPD.

Results

The combination of the inverse variance weighting method and the Bayesian weighting algorithm identified 30 immune cells that were found to be causally associated with COPD, as well as eight inflammatory proteins that were associated with COPD. By two-step analysis, six inflammatory proteins were found to mediate the effects of eight immune cell phenotypes on COPD, with CXCL10 having the highest percentage of mediation at 14.49%, followed by IL20RA at 11.47%.

Conclusion

This study provides a comprehensive investigation of the causal relationship between immune cells and COPD, as well as an estimation of the proportion of the effect of inflammatory proteins as mediators. These findings facilitate the identification of individuals at high risk of COPD and offer novel insights for early prevention and clinical intervention.

The Interplay of Heart Failure and Lung Disease: Clinical Correlations, Mechanisms, and Therapeutic Implications

Heart failure (HF) is a common clinical syndrome marked by reduced cardiac output, elevated intracardiac pressures, and heart dysfunction. Chronic HF (CHF) is a syndrome characterized by a lack of blood flow and impaired pumping ability to the heart over time, while acute HF (AHF) arises suddenly due to incidents like myocardial infarction or cardiac arrest. HF has a significant impact on pulmonary health and function, leading to conditions such as pulmonary edema and restrictive lung patterns. Clinical evidence highlights the bidirectional relationship between HF and lung dysfunction. Declining lung function serves as a predictor for HF progression and severity, while HF contributes to worsening lung health. Animal models that induce HF through surgical methods further demonstrate the connection between heart and lung pathology. The main mechanisms linking HF and lung dysfunction are pressure overload and chronic systemic inflammation, with changes in the extracellular matrix (ECM) also playing a role. Additionally, environmental factors like air pollution exacerbate lung inflammation, increasing the risk of both HF and chronic obstructive pulmonary disease (COPD) incidence. Combined treatment approaches involving pharmaceutical drugs such as statins, Angiotensin-converting enzyme (ACE) inhibitors, and Angiotensin receptor blockers (ARBs) may benefit by reducing inflammation. This review will explore the complex interplay between HF and lung function, emphasizing their interconnected pathophysiology and potential integrated treatment strategies.

Biomarkers of Inflammation and Longitudinal Evaluation of Lung Function, Physical Activity, and Grip Strength: A Secondary Analysis in the CASCADE Study

Rationale

Physical activity, lung function, and grip strength are associated with exacerbations, hospitalizations, and mortality in people with chronic obstructive pulmonary disease (COPD). We tested whether baseline inflammatory biomarkers were associated with longitudinal outcomes of these physiologic measurements.

Methods

The COPD Activity: Serotonin Transporter, Cytokines, and Depression (CASCADE) study was a prospective observational study of individuals with COPD. A total of 14 inflammatory biomarkers were measured at baseline. Participants were followed for 2 years. We analyzed associations between baseline biomarkers and forced expiratory volume in 1 second (FEV1), physical activity, and grip strength. We used a hierarchical hypothesis testing procedure to reduce type I error. We used Pearson correlations to test associations between baseline biomarkers and longitudinal changes in the outcomes of interest. We used Fisher's linear discriminant analysis to test if linear combinations of baseline biomarkers predict rapid FEV1 decline. Finally, we used linear mixed modeling to test associations between baseline biomarkers and outcomes of interest at baseline, year 1, and year 2; models were adjusted for age, smoking status, baseline biomarkers, and FEV1.

Results

A total of 302 participants (age 67.5 ± 8.5 years, 19.5% female, 28.5% currently smoking) were included. Baseline biomarkers were not associated with longitudinal changes in grip strength, physical activity, or rapid FEV1 decline. Higher interleukin-6 and C-reactive protein were associated with lower physical activity at baseline and these relationships persisted at year 1 and year 2.

Conclusion

Baseline inflammatory biomarkers did not predict changes in lung function or physical activity, but higher inflammatory biomarkers were associated with persistently low levels of physical activity.

A Patented Dietary Supplement (Hydroxy-Methyl-Butyrate, Carnosine, Magnesium, Butyrate, Lactoferrin) Is a Promising Therapeutic Target for Age-Related Sarcopenia through the Regulation of Gut Permeability: A Randomized Controlled Trial

Adequate diet, physical activity, and dietary supplementation with muscle-targeted food for special medical purposes (FSMP) or dietary supplement (DS) are currently considered fundamental pillars in sarcopenia treatment. The aim of this study is to evaluate the effectiveness of a DS (containing hydroxy-methyl-butyrate, carnosine, and magnesium, for its action on muscle function and protein synthesis and butyrate and lactoferrin for their contribution to the regulation of gut permeability and antioxidant/anti-inflammation activity) on muscle mass (assessed by dual X-ray absorptiometry (DXA)), muscle function (by handgrip test, chair test, short physical performance battery (SPPB) test, and walking speed test), inflammation (tumor necrosis factor-alpha (TNF-a), C-reactive protein (CRP), and visceral adipose tissue (VAT)) and gut axis (by zonulin). A total of 59 participants (age 79.7 ± 4.8 years, body mass index 20.99 ± 2.12 kg/m2) were enrolled and randomly assigned to intervention (n = 30) or placebo (n = 28). The skeletal muscle index (SMI) significantly improved in the supplemented group compared to the placebo one, +1.02 (CI 95%: -0.77; 1.26), p = 0.001; a significant reduction in VAT was observed in the intervention group, -70.91 g (-13.13; -4.70), p = 0.036. Regarding muscle function, all the tests significantly improved (p = 0.001) in the supplemented group compared to the placebo one. CRP, zonulin, and TNF-alpha significantly decreased (p = 0.001) in intervention, compared to placebo, -0.74 mg/dL (CI 95%: -1.30; -0.18), -0.30 ng/mL (CI 95%: -0.37; -0.23), -6.45 pg/mL (CI 95%: -8.71; -4.18), respectively. This DS improves muscle mass and function, and the gut muscle has emerged as a new intervention target for sarcopenia.

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.

The Health, Aging, and Body Composition (Health ABC) Study-Ground-Breaking Science for 25 Years and Counting

BACKGROUND

The Health, Aging, and Body Composition Study is a longitudinal cohort study that started just over 25 years ago. This ground-breaking study tested specific hypotheses about the importance of weight, body composition, and weight-related health conditions for incident functional limitation in older adults.

METHODS

Narrative review with analysis of ancillary studies, career awards, publications, and citations.

RESULTS

Key findings of the study demonstrated the importance of body composition as a whole, both fat and lean mass, in the disablement pathway. The quality of the muscle in terms of its strength and its composition was found to be a critical feature in defining sarcopenia. Dietary patterns and especially protein intake, social factors, and cognition were found to be critical elements for functional limitation and disability. The study is highly cited and its assessments have been widely adopted in both observational studies and clinical trials. Its impact continues as a platform for collaboration and career development.

CONCLUSIONS

The Health ABC provides a knowledge base for the prevention of disability and promotion of mobility in older adults.

Protocol for a systematic review of the associations between inflammatory markers and lung function, muscle force and exercise capacity in people with COPD

INTRODUCTION

The prevalence of chronic obstructive pulmonary disease (COPD) has been on the rise, with acute exacerbation of COPD associated with the highest burden and multiple pulmonary and systemic consequences. People with COPD have been found to have an abnormal response of systemic inflammation. To date, although limited, there are studies that suggest negative associations between inflammatory markers and important clinical outcomes such as exercise capacity and muscle force. This protocol aims to systematically review the evidence for (i) the associations between inflammatory markers and lung function, muscle force and exercise capacity and (ii) the influence of other factors (eg, hospitalisation, exercise programme) on the level of inflammatory markers in people with COPD.

METHODS AND ANALYSIS

Scopus, PubMed, Cochrane, Web of Science and ProQuest will be searched from database inception to February 2023 using PEO search strategy (Population: adults with COPD; Exposure: inflammatory markers; Outcomes: lung function, muscle force and exercise capacity). Four reviewers working in pairs will independently screen articles for eligibility and extract data that fulfilled the inclusion criteria. Depending on the design of the included studies, either Cochrane risk-of-bias version 2 or the Newcastle-Ottawa Scale tools will be used to rate the methodological quality of the included studies. Effect sizes reported in each individual study will be standardised to Cohen's d and a random effects model will be used to calculate the pooled effect size for the association.

ETHICS AND DISSEMINATION

Ethical approval is unnecessary as this study will only use publicly available data. The findings will be disseminated through publication in peer-reviewed journals and conferences.

PROSPERO REGISTRATION NUMBER

CRD42022284446.

Main Pathogenic Mechanisms and Recent Advances in COPD Peripheral Skeletal Muscle Wasting

Chronic obstructive pulmonary disease (COPD) is a worldwide prevalent respiratory disease mainly caused by tobacco smoke exposure. COPD is now considered as a systemic disease with several comorbidities. Among them, skeletal muscle dysfunction affects around 20% of COPD patients and is associated with higher morbidity and mortality. Although the histological alterations are well characterized, including myofiber atrophy, a decreased proportion of slow-twitch myofibers, and a decreased capillarization and oxidative phosphorylation capacity, the molecular basis for muscle atrophy is complex and remains partly unknown. Major difficulties lie in patient heterogeneity, accessing patients' samples, and complex multifactorial process including extrinsic mechanisms, such as tobacco smoke or disuse, and intrinsic mechanisms, such as oxidative stress, hypoxia, or systemic inflammation. Muscle wasting is also a highly dynamic process whose investigation is hampered by the differential protein regulation according to the stage of atrophy. In this review, we report and discuss recent data regarding the molecular alterations in COPD leading to impaired muscle mass, including inflammation, hypoxia and hypercapnia, mitochondrial dysfunction, diverse metabolic changes such as oxidative and nitrosative stress and genetic and epigenetic modifications, all leading to an impaired anabolic/catabolic balance in the myocyte. We recapitulate data concerning skeletal muscle dysfunction obtained in the different rodent models of COPD. Finally, we propose several pathways that should be investigated in COPD skeletal muscle dysfunction in the future.

Associations Between Muscle Weakness and Clinical Outcomes in Current and Former Smokers

Introduction

Smokers with chronic obstructive pulmonary disease (COPD) are at increased risk of muscle weakness. There are limited data describing weakness in smokers with normal spirometry and preserved ratio-impaired spirometry (PRISm), 2 subgroups at risk of respiratory symptom burden and activity limitations. In this study, we evaluated the associations of 2 weakness measures, sit-to-stand (STS) and handgrip strength (HGS), with clinical outcomes in smokers with COPD, normal spirometry, and PRISm.

Methods

We evaluated 1972 current and former smokers from the COPD Genetic Epidemiology (COPDGene®) cohort with STS and HGS measurements at their 10-year study visit. Multivariable regression modeling was used to assess associations between weakness measures and the 6-minute walk distance (6MWD) test, the St George's Respiratory Questionnaire (SGRQ), the Short-Form-36 (SF-36), severe exacerbations, and prospective mortality, reported as standardized coefficients (β), odds ratios (ORs), or hazard ratios (HRs).

Results

Compared with HGS, STS was more strongly associated with the 6MWD (β=0.45, p<0.001 versus. β=0.25, p<0.001), SGRQ (β=-0.24, p<0.001 versus β=-0.18, p<0.001), SF-36 Physical Functioning (β=0.36, p<0.001 versus β=0.25, p<0.001), severe exacerbations (OR 0.95, p=0.04 versus OR 0.97, p=0.01), and prospective mortality (HR 0.83, p=0.001 versus HR 0.94, p=0.03). Correlations remained after stratification by spirometric subgroups. Compared with males, females had larger magnitude effect sizes between STS and clinical outcomes.

Conclusions

STS and HGS are easy to perform weakness measures that provide important information about functional performance, health-related quality of life, severe exacerbations, and survival in smokers, regardless of spirometric subgroup. This iterates the importance of screening current and former smokers for weakness in the outpatient setting.

Dysregulated myokines and signaling pathways in skeletal muscle dysfunction in a cigarette smoke–induced model of chronic obstructive pulmonary disease

Skeletal muscle dysfunction is an important extrapulmonary comorbidity of chronic obstructive pulmonary disease (COPD). Muscle-derived cytokines (myokines) play important roles in skeletal muscle growth and function, but their contributions to skeletal muscle dysfunction in COPD have not been fully understood. In the current study, by using a well-established mouse model of COPD with skeletal muscle dysfunction, we found that the expressions of Fndc5 (fibronectin type III domain-containing protein 5, the precursor of irisin) and peroxisome proliferator-activated receptor-γ coactivator 1α (PGC-1α) were decreased, while myostatin (Mstn), phosphorylated extracellular regulated kinase (p-Erk1/2), and p-Smad3 expressions were upregulated in skeletal muscles from cigarette smoke-exposed mice and in cigarette smoke extract (CSE)-stimulated C2C12 myotubes. Treatment with Smad3 or Erk1/2 inhibitors partially restored the expression of Fndc5 in CSE-stimulated C2C12 myotubes. Taken together, CSE exposure, by upregulation of p-Erk1/2, promoted the expression of Mstn, which further inhibited Fndc5 expression by the p-Smad3/PGC-1α pathway, revealing a novel regulating mechanism of myokines in the pathogenesis of skeletal muscle comorbidities of COPD.

Skeletal Myosteatosis is Associated with Systemic Inflammation and a Loss of Muscle Bioenergetics in Stable COPD

Background

Common features among patients with more advanced chronic obstructive pulmonary disease (COPD) are systemic inflammation and a loss of both muscle mass and normal muscle composition. In the present study, we investigated COPD subjects to better understand how thigh muscle fat infiltration (MFI) and energy metabolism relate to each other and to clinical features of COPD with emphasis on systemic inflammation.

Methods

Thirty-two Caucasians with stable COPD were investigated using questionnaires, lung function tests, blood analysis and magnetic resonance imaging (MRI) for analysis of body- and thigh muscle composition. Bioenergetics in the resting thigh muscle, expressed as the PCr/Pi ratio, were analysed using ³¹phosphorus magnetic resonance spectroscopy (³¹P-MRS).

Results

Based on the combination of the MFI adjusted for sex (MFI_a) and the thigh fat-tissue free muscle volume, expressed as the deviation from the expected muscle volume of a matched virtual control group (FFMV_vcg), all COPD subjects displayed abnormally composed thigh muscles. Clinical features of increased COPD severity, including a decrease of blood oxygenation (r = −0.44, p < 0.05) and FEV₁/FVC ratio, reflecting airway obstruction (r = −0.53, p < 0.01) and an increase of COPD symptoms (r = 0.37, p < 0.05) and breathing frequency at rest (r = 0.41, p < 0.05), were all associated with a raise of the PCr/Pi ratio in the thigh muscle. Increased MFI_a of the thigh muscle correlated positively with markers of systemic inflammation (white blood cell count, r = 0.41, p < 0.05; fibrinogen, r = 0.44, p < 0.05), and negatively with weekly physical activity (r = −0.40, p < 0.05) and the PCr/Pi ratio in the resting thigh muscle (r = −0.41, p < 0.05).

Conclusion

The present study implies a link between systemic inflammation, excessive MFI and a loss of bioenergetics in subjects with stable COPD.

Pathophysiology of COPD

This article provides an overview of the pathophysiology of chronic obstructive pulmonary disease including the physiological mechanisms that are known precursors. The roles of environmental and genetic causes are considered. α1-Antitrypsin deficiency is also discussed as it relates to the development of airflow obstruction.

Association of lung function with functional limitation in older adults: A cross-sectional study

INTRODUCTION

Impaired lung function is independently associated with higher rates of disability, however, few studies have examined the association between lung function and functional limitation. This study aimed to assess this association and dose-response relationship in older adults.

METHODS

Data from the National Health and Nutrition Examination Survey (2007-2012) was used as a cross-sectional study. Lung function was determined by Forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC). Functional limitation in older adults was identified by six self-reported questions on physical function. 3070 adults aged 60 and over were enrolled in our study. Logistic regression models and restricted cubic spline models were applied to examine the association between lung function and the risk of functional limitation.

RESULTS

FEV1 and FVC were inversely associated with the risk of functional limitation. In the full adjusted model, compared with the lowest tertile of FEV1, the odds ratios (95% confidence intervals) of functional limitation for tertile 2 and tertile 3 were 0.5422 (0.3848-0.7639) and 0.4403 (0.2685-0.7220), and the odds ratios (95% confidence intervals) of functional limitation for tertile 2 and tertile 3 of FVC were 0.5243 (0.3503-0.7848) and 0.3726 (0.2072-0.6698). Furthermore, an inverse association persisted after stratified analysis by gender and sensitivity analysis. Dose-response analyses showed that the odds of functional limitation declined with increase in FEV1 and FVC in a nonlinear manner.

CONCLUSIONS

Lung function was inversely associated with functional limitation among older adults.

Association of circulating C-reactive protein and high-sensitivity C-reactive protein with components of sarcopenia: A systematic review and meta-analysis of observational studies

BACKGROUND

Sarcopenia, a multi-faceted skeletal muscle disorder in the older population, has poor health outcomes. Some previous observational studies investigated the association between circulating inflammatory markers and sarcopenia components to evaluate chronic inflammation as a risk factor for sarcopenia in the elderly population. Nevertheless, the association between circulating C-reactive protein (CRP) and hs-CRP, as the recognized markers of systemic inflammation and components of sarcopenia, is unclear. This meta-analysis aimed to investigate the association of muscle strength, muscle mass, and muscle function with two serum inflammatory markers, circulating C-reactive protein (CRP) and high-sensitive CRP (hs-CRP).

METHODS

We assessed all observational studies across different electronic databases including PubMed, Scopus, and Google Scholar using keywords such as "muscle strength", "muscle mass", "muscle function", CRP and hs-CRP from inception until the 30th of July 2019. Only studies that investigated the association between components of sarcopenia and CRP or hs-CRP levels were included. Participants' country, age, sex, BMI, and screening tool for sarcopenia were retrieved. The correlations between muscle strength, muscle mass, and muscle function with CRP, and hs-CRP were expressed as the correlation coefficient (r) with 95% confidence intervals (CIs). Begg's test and Egger's test were conducted to evaluate risk of publication bias in this study.

RESULTS

Initially, we found fifty-nine studies for the qualitative synthesis. Ultimately, nineteen adult cross-sectional studies comprising 14,650 subjects were included in the meta-analysis. Of them, fourteen studies measured the correlation between CRP or hs-CRP and muscle strength. There were significant inverse correlation between CRP and hs-CRP concentrations with muscle strength (ES (z) = -0.22; 95% CI = -0.34 to -0.09; P < 0.001), (ES (z) = -0.22; 95% CI = -0.34 to -0.09; P < 0.001), respectively. No publication bias was found between muscle strength and CRP (P = 0.53) or hs-CRP (P = 0.62) respectively.

CONCLUSION

Among diagnostic components of sarcopenia, impairment of muscle strength was independently associated with both inflammatory biomarkers. However, future cohort studies are essential to clarify the causal correlation.

Muscle-Bone Crosstalk in Chronic Obstructive Pulmonary Disease

Sarcopenia and osteoporosis are common musculoskeletal comorbidities of chronic obstructive pulmonary disease (COPD) that seriously affect the quality of life and prognosis of the patient. In addition to spatially mechanical interactions, muscle and bone can also serve as endocrine organs by producing myokines and osteokines to regulate muscle and bone functions, respectively. As positive and negative regulators of skeletal muscles, the myokines irisin and myostatin not only promote/inhibit the differentiation and growth of skeletal muscles, but also regulate bone metabolism. Both irisin and myostatin have been shown to be dysregulated and associated with exercise and skeletal muscle dysfunction in COPD. During exercise, skeletal muscles produce a large amount of IL-6 which acts as a myokine, exerting at least two different conflicting functions depending on physiological or pathological conditions. Remarkably, IL-6 is highly expressed in COPD, and considered to be a biomarker of systemic inflammation, which is associated with both sarcopenia and bone loss. For osteokines, receptor activator of nuclear factor kappa-B ligand (RANKL), a classical regulator of bone metabolism, was recently found to play a critical role in skeletal muscle atrophy induced by chronic cigarette smoke (CS) exposure. In this focused review, we described evidence for myokines and osteokines in the pathogenesis of skeletal muscle dysfunction/sarcopenia and osteoporosis in COPD, and proposed muscle-bone crosstalk as an important mechanism underlying the coexistence of muscle and bone diseases in COPD.

Low Vitamin D Status Is Associated with Inflammation in Patients with Chronic Obstructive Pulmonary Disease

Vitamin D deficiency is associated with increased risks of chronic obstructive pulmonary disease (COPD). Nevertheless, the mechanisms remain unknown. This study analyzed the correlations between vitamin D levels and inflammation in COPD patients. One hundred and one patients with COPD and 202 control subjects were enrolled. Serum 25(OH)D level and inflammatory cytokines were detected. Serum 25(OH)D was decreased and inflammatory cytokines were increased in COPD patients. According to forced expiratory volume in 1 s, COPD patients were divided into three grades. Furthermore, serum 25(OH)D was gradually decreased in COPD patients ranging from grade 1-2 to 4. Serum 25(OH)D was inversely associated with inflammatory cytokines in COPD patients. Further analysis found that NF-κB and AP-1 signaling were activated in COPD patients. Besides, inflammatory signaling was gradually increased in parallel with the severity of COPD. By contrast, pulmonary nuclear vitamin D receptor was decreased in COPD patients. In vitro experiments showed that 1,25(OH)₂D₃ inhibited LPS-activated inflammatory signaling in A549 cells (human lung adenocarcinoma cell). Mechanically, 1,25(OH)₂D₃ reinforced physical interactions between vitamin D receptor with NF-κB p65 and c-Jun. Our results indicate that vitamin D is inversely correlated with inflammatory signaling in COPD patients. Inflammation may be a vital mediator of COPD progress in patients with low vitamin D levels.

Inflammation Increases Susceptibility of Human Small Airway Epithelial Cells to Pneumonic Nanotoxicity

Exposure to inhaled anthropogenic nanomaterials (NM) with dimension <100 nm has been implicated in numerous adverse respiratory outcomes. Although studies have identified key NM physiochemical determinants of pneumonic nanotoxicity, the complex interactive and cumulative effects of NM exposure, especially in individuals with preexisting inflammatory respiratory diseases, remain unclear. Herein, the susceptibility of primary human small airway epithelial cells (SAEC) exposed to a panel of reference NM, namely, CuO, ZnO, mild steel welding fume (MSWF), and nanofractions of copier center particles (Nano-CCP), is examined in normal and tumor necrosis factor alpha (TNF-α)-induced inflamed SAEC. Compared to normal SAEC, inflamed cells display an increased susceptibility to NM-induced cytotoxicity by 15-70% due to a higher basal level of intracellular reactive oxygen species (ROS). Among the NM screened, ZnO, CuO, and Nano-CCP are observed to trigger an overcompensatory response in normal SAEC, resulting in an increased tolerance against subsequent oxidative insults. However, the inflamed SAEC fails to adapt to the NM exposure due to an impaired nuclear factor erythroid 2-related factor 2 (Nrf2)-mediated cytoprotective response. The findings reveal that susceptibility to pulmonary nanotoxicity is highly dependent on the interplay between NM properties and inflammation of the alveolar milieu.

GTS-21, an α7nAChR agonist, suppressed the production of key inflammatory mediators by PBMCs that are elevated in COPD patients and associated with impaired lung function

Chronic obstructive pulmonary disease (COPD) is a lung inflammatory disease characterized by progressive airflow limitation, chronic respiratory symptoms and frequent exacerbations. There is an unmet need to identify novel therapeutic alternatives beside bronchodilators that prevent disease progression. Levels of both Nitric Oxide (NO) and IL-6 were significantly increased in the plasma of patients in the exacerbation phase (ECOPD, n = 13) when compared to patients in the stable phase (SCOPD, n = 38). Levels of both NO and IL-6 were also found to inversely correlate with impaired lung function (%FEV1 predicted). In addition, there was a strong positive correlation between levels of IL-6 and NO found in the plasma of patients and those spontaneously produced by their peripheral blood mononuclear cells (PBMCs), identifying these cells as a major source of these key inflammatory mediators in COPD. GTS-21, an agonist for the alpha 7 nicotinic receptors (α7nAChR), was found to exert immune-modulatory actions in PBMCs of COPD patients by suppressing the production of IL-6 and NO. This study provides the first evidence supporting the therapeutic potential of α7nAChR agonists in COPD due to their ability to suppress the production of key inflammatory markers associated with disease severity.

Smoking, Systemic Inflammation, and Airflow Limitation: A Mendelian Randomization Analysis of 98 085 Individuals From the General Population

INTRODUCTION

Smoking is associated with systemic and local inflammation in the lungs. Furthermore, in chronic obstructive pulmonary disease, which is often caused by smoking, there is often systemic inflammation that is linked to lung function impairment. However, the causal pathways linking smoking, systemic inflammation, and airflow limitation are still unknown. We tested whether higher tobacco consumption is associated with higher systemic inflammation, observationally and genetically and whether genetically higher systemic inflammation is associated with airflow limitation.

METHODS

We included 98 085 individuals aged 20-100 years from the Copenhagen General Population Study; 36589 were former smokers and 16172 were current smokers. CHRNA3 rs1051730 genotype was used as a proxy for higher tobacco consumption and the IL6R rs2228145 genotype was used for higher systemic inflammation. Airflow limitation was defined as forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) <70%.

RESULTS

Difference in plasma level of C-reactive protein was 4.8% (95% CI = 4.4% to 5.2%) per 10 pack-year increase and 1.6% (95% CI = 0.4% to 2.8%) per T allele. Corresponding differences were 1.2% (95% CI = 1.1% to 1.3%) and 0.5% (95% CI = 0.3% to 0.8%) for fibrinogen, 1.2% (95% CI = 1.2% to 1.3%) and 0.7% (95% CI = 0.5% to 1.0%) for α1-antitrypsin, 2.0% (95% CI = 1.8% to 2.1%) and 0.7% (95% CI = 0.4% to 1.1%) for leukocytes, 1.9% (95% CI = 1.8% to 2.1%) and 0.8% (95% CI = 0.4% to 1.2%) for neutrophils, and 0.8% (95% CI = 0.7% to 1.0%) and 0.4% (95% CI = 0.1% to 0.7%) for thrombocytes. The differences in these levels were lower for former smokers compared with current smokers. The IL6R rs2228145 genotype was associated with higher plasma acute-phase reactants but not with airflow limitation. Compared with the C/C genotype, the odds ratio for airflow limitation was 0.95 (95% CI = 0.89 to 1.02) for A/C genotype and 0.94 (95% CI = 0.87 to 1.01) for A/A genotype.

CONCLUSIONS

Higher tobacco consumption is associated with higher systemic inflammation both genetically and observationally, whereas systemic inflammation was not associated with airflow limitation genetically.

IMPLICATIONS

The association between higher tobacco consumption and higher systemic inflammation may be causal, and the association is stronger among current smokers compared to former smokers, indicating that smoking cessation may reduce the effects of smoking on systemic inflammation. Systemic inflammation does not seem to be a causal driver in development of airflow limitation. These findings can help to understand the pathogenic effects of smoking and the interplay between smoking, systemic inflammation, and airflow limitation and hence development and progression of chronic obstructive pulmonary disease.

Are Dietary Factors Associated with Lung Function in Canadian Adults?

Purpose: The purpose of this study was to explore the impact of dietary factors and biomarkers on lung function among Canadian adults (18-79 years). Methods: Our data source was the Canadian Health Measures Survey Cycle-3, which included 3397 adults. The household and clinic questionnaires and physical measures were used to assess individual dietary factors, modified Mediterranean Diet Scores, and biomarkers. Results: The overall mean percent predicted values for FVC and FEV₁ were 97% and 95%, respectively. While somewhat inconsistent between outcomes, higher lung function was associated with bean, grain, milk, fruit, and vegetable consumption, whereas lower lung function was associated with egg and potato consumption. Among the biomarkers, vitamin D, chloride, total serum protein, and red blood cell folate were associated with higher lung function, whereas C-reactive protein and vitamin B₁₂ was associated with lower lung function. Conclusion: Our study provides support for an association between some dietary factors and lung function, though not entirely consistent between a specific dietary factor and the outcomes studied (FVC, FEV₁, FVC/FEV₁, and FEF_25%-75%). The associations between a specific biomarker and lung function were more consistent (i.e., observed with a larger number of lung function outcomes) than were the dietary factors.

Effects of conjugated linoleic acid supplementation on serum levels of interleukin-6 and sirtuin 1 in COPD patients

OBJECTIVE

Chronic obstructive pulmonary disease (COPD) is characterized by systemic inflammation and accelerated inflammaging of the lungs. Some studies showed that conjugated linoleic acid (CLA) has anti-inflammatory effects. The aim of the present study was to evaluate the effect of CLA supplementation on serum levels of interleukin (IL)-6 and sirtuin1 (SIRT1) in patients with COPD.

MATERIALS AND METHODS

82 patients with stable COPD were enrolled in a double blind clinical trial. Subjects were randomly assigned to two groups: placebo (n=42) and 3.2 g CLA daily supplementation (n=40). Forced expiratory volume in one second (FEV1%), BODE index, and serum levels of IL-6, and SIRT1 were measured at the baseline and six weeks after the intervention. In addition, the study parameters in the two groups were compared based on the Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria.

RESULTS

After supplementation with CLA, serum levels of IL-6 and BODE index significantly decreased (p<0.05 and p<0.001, respectively). In addition, serum levels of SIRT1 (p<0.01) and FEV1 (p<0.001) significantly increased in the supplementation group. Based on GOLD criteria, the increase in SIRT1 and the decrease in IL-6 serum levels were found to be statistically significant in stages III and IV in the supplementation group (p<0.05 and p<0.01, respectively).

CONCLUSION

Supplementation with CLA can modify the inflammatory markers and improve the health status of COPD patients. The results suggest that CLA supplementation in COPD patients can be useful in the management of the disease.

Characteristics of air pollutants inside and outside a primary school classroom in Beijing and respiratory health impact on children

This study investigated the spatial and temporal distributions of particulate and gaseous air pollutants in a primary school in Beijing and assessed their health impact on the children. The results show that air quality inside the classroom was greatly affected by the input of outdoor pollutants; high levels of pollution were observed during both the heating and nonheating periods and indicate that indoor and outdoor air pollution posed a threat to the children's health. Traffic sources near the primary school were the main contributors to indoor and outdoor pollutants during both periods. Moreover, air quality in this primary school was affected by coal combustion and atmospheric reactions during the heating and nonheating periods, respectively. Based on the estimation by exposure-response functions and the weighting of indoor and outdoor pollutants during different periods, the levels of PM_2.5, PM ₁₀ and O₃ at school had adverse respiratory health effects on children. Longer exposures during the nonheating period contributed to higher health risks. These results emphasized that emission sources nearby had a direct impact on air quality in school and children's respiratory health. Therefore, measures should be taken for double control on air pollution inside and outside the classroom to protect children from it.

Systematic Review: Components of a Comprehensive Geriatric Assessment in Inflammatory Bowel Disease-A Potentially Promising but Often Neglected Risk Stratification

BACKGROUND

The population of older patients with inflammatory bowel disease [IBD] is increasing. Patient age does not fully account for poor outcomes and its clinical utility for risk stratification is limited. Comprehensive geriatric assessment [CGA], comprising a somatic, functional, mental, and social assessment or frailty, could be a predictor tool.

AIMS

To systematically review literature on the kind of components of a CGA being used in adult IBD patients and the association of these components with adverse health outcomes.

METHODS

An electronic literature search was performed on January 16, 2018, using PubMed, Embase, Web of Science, the Cochrane Library, CENTRAL, Emcare, and PsycINFO. Longitudinal studies relating somatic, functional, mental, and social assessment or frailty to adverse health outcomes during follow-up in IBD patients were included. The Newcastle-Ottawa scale was used to assess individual study quality.

RESULTS

Of 4080 identified citations, 27 studies were included, reporting 169 associations. Median sample size was 108 patients (interquartile range [IQR] 60-704). No studies performed subgroup analyses on older patients, and the highest mean age reported was 52.7 years. Somatic and functional assessments were used in three studies, mental in 24, and social in five. No study assessed cognitive status, functional performance, or frailty. In 62 associations [36.7%], components of a CGA were significantly associated with adverse health outcome measurements.

CONCLUSIONS

Components of a CGA were associated with adverse health outcomes in IBD patients, but older patients were under-represented. More studies among older patients with IBD are warranted to further establish the clinical impact of a CGA.

Does Poorer Pulmonary Function Accelerate Arterial Stiffening?: A Cohort Study With Repeated Measurements of Carotid-Femoral Pulse Wave Velocity

Whether poorer pulmonary function accelerates progression of arterial stiffness remains unknown as prior observational studies have not examined longitudinal changes in arterial stiffness in relation to earlier pulmonary function. Data (N=5342, 26% female) were drawn from the Whitehall II cohort study. Participants completed repeated assessments of forced expiratory volume in 1 second (FEV₁, L) and carotid-femoral pulse wave velocity (cf-PWV, m/s) over 5 years. The effect of FEV₁ on later cf-PWV and its progression was estimated using linear mixed-effects modeling. Possible explanatory mechanisms, such as mediation by low-grade systemic inflammation, common-cause explanation by preexisting cardiometabolic risk factors, and reverse-causation bias, were assessed. Poorer pulmonary function was associated with later higher cf-PWV and its subsequent progression (cf-PWV 5-year change 0.09, 95% CI 0.03–0.17 per SD lower FEV₁) after adjustment for age, sex, ethnicity, heart rate, and mean arterial pressure. Decrease in pulmonary function was associated with later higher cf-PWV (0.17, 95% CI 0.04–0.30 in the top compared to bottom quartile of decline in FEV₁). There was no evidence to support mediation by circulating CRP (C-reactive protein) or IL (interleukin)-6. Furthermore, arterial stiffness was not associated with later FEV₁ after accounting for cardiometabolic status. In conclusion, poorer pulmonary function predicted future arterial stiffness. These findings support pulmonary function as a clinically important risk factor for arterial stiffness and provide justification for future intervention studies for pulmonary function based on its relationship with arterial stiffness.

Association of Symptoms of Obstructive Lung Disease and All-Cause Mortality in Older Adult Smokers

OBJECTIVES

This study aims to investigate the impact of respiratory symptoms in current and former smokers with and without obstructive lung disease (OLD) on all-cause mortality.

DESIGN

Secondary analysis in a prospective cohort (the Health, Aging and Body Composition study).

SETTING

Memphis, Tennessee, and Pittsburgh, Pennsylvania.

PARTICIPANTS

Black and white men and women with a history of current and former smoking (N = 596; 63% male and 37% female) aged 70-79 years followed for 13 years. Participants were categorized into 4 mutually exclusive groups based on symptom profile and forced expiratory volume in the 1st second to forced vital capacity ratio. The groups were Less Dyspnea-No OLD (N = 196), More Dyspnea-No OLD (N = 104), Less Dyspnea-With OLD (N = 162), and More Dyspnea-With OLD (N = 134).

MEASUREMENTS

All-cause mortality.

RESULTS

Overall, 53% in Less Dyspnea-No OLD, 63% in More Dyspnea-No OLD, 67% in Less Dyspnea-With OLD, and 84% in More Dyspnea-With OLD died within the 13- year follow up period (log-rank χ²  = 44.4, P < .0001). The hazard ratio was highest for participants with OLD, both with (HR =1.91, 95% CI 1.44 - 2.54; P < .0001) and without dyspnea (HR = 1.52, 95% CI 1.15 - 2.02; p = .004). Participants without OLD but with dyspnea had a similar risk of death to subjects who had OLD but fewer symptoms.

CONCLUSIONS

OLD is associated with high risk of death with different risk profiles based on symptom group. Patients with symptoms of shortness of breath without OLD should be considered an at-risk group given their similar mortality to those with OLD with minimal symptoms. J Am Geriatr Soc 67:2116-2122, 2019.

Higher serum levels of systemic inflammatory markers are linked to greater inspiratory muscle dysfunction in COPD

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is associated with an inflammatory response that becomes more pronounced in acute exacerbations. Considerable attention has recently focused on the value of several inflammatory mediators in predicting worsening of COPD-related symptoms. Whereas respiratory muscle dysfunction is also widely present in this population, little is known about how systemic inflammation relates to inspiratory muscle dysfunction in COPD.

METHODS

Fifty-three males with mild-to-very severe airflow obstruction underwent blood sampling for 23 inflammatory markers, including acute-phase proteins, cytokines and adipokines. Inspiratory muscle performance was assessed via the test of incremental respiratory endurance, providing measures of maximal (MIP) and sustained maximal (SMIP) inspiratory pressures.

RESULTS

The mean ± SD MIP and SMIP were 75.32 ± 19.62 cmH₂ O and 406.15 ± 124.55 PTU. MIP negatively correlated with CRP, SAA and cystatin C (r-values from -0.333 to -0.378, P < 0.02), while SMIP was inversely related to SAA and cystatin C (r = -0.534 and r = -0.396, P = 0.00). Significant differences in CRP, SAA, cystatin C and PARC were also found between subjects with and without inspiratory muscle weakness. No additional significant relationships were observed between either MIP or SMIP and other inflammatory markers in the study.

CONCLUSIONS

MIP and SMIP are markedly reduced with greater degrees of inflammation in COPD as expressed by higher levels of CRP, SAA and cystatin C. Future research is needed to further examine the above findings and determine the impact of systemic inflammation along with its underlying mechanisms on inspiratory muscle function in COPD.

Theophylline inhibits cigarette smoke-induced inflammation in skeletal muscle by upregulating HDAC2 expression and decreasing NF-κB activation

Inflammation is associated with skeletal muscle dysfunction and atrophy in patients with chronic obstructive pulmonary disease (COPD). Theophylline has an anti-inflammatory role in COPD. However, the effects of theophylline on inflammation in skeletal muscle in COPD have rarely been reported. The aims of this study were to explore whether theophylline has an anti-inflammatory effect on skeletal muscle in a mouse model of emphysema and to investigate the molecular mechanism underlying this effect. In mice, cigarette smoke (CS) exposure for 28 wk resulted in atrophy of the gastrocnemius muscle. Histone deacetylase 2 (HDAC2) and nuclear factor-κBp65 (NF-κBp65) mRNA and protein levels were significantly decreased and increased, respectively, in gastrocnemius muscle. This effect was revered by aminophylline. The exposure of murine skeletal muscle C2C12 cells to CS extract (CSE) significantly increased IL-8 and TNF-α levels as well as NF-κBp65 mRNA and protein levels and NF-κBp65 activity. This effect was reversed by theophylline. HDAC2 knockdown enhanced the activity of NF-κBp65 and increased IL-8 and TNF-α levels in C2C12 cells. CSE significantly increased the interaction of HDAC2 with NF-κBp65 in C2C12 cells. These data suggest that theophylline has an anti-inflammatory effect on skeletal muscle in a mouse model of emphysema by upregulating HDAC2 expression and decreasing NF-κBp65 activation.

Serum inflammatory markers and nutritional status in patients with stable chronic obstructive pulmonary disease

Background

Chronic obstructive pulmonary disease (COPD) is a systemic inflammatory disease. We investigated whether serum inflammatory markers, C-reactive protein (CRP), leptin, and nutritional status (assessed by measurement of serum levels of prealbumin and anthropometry) correlated with COPD severity.

Materials and Methods

One-hundred and two COPD patients (mean age 56.94 ± 10.95 years) were recruited and classified into severity categories based on the GOLD guidelines. Serum concentrations of CRP, prealbumin, and leptin were measured. Anthropometry included body mass index (BMI), mid-upper arm circumference (MUAC), and sum of four skinfold thicknesses (triceps, biceps, suprailiac, and subscapular).

Results

Twenty-one patients had moderate, 44 had severe, and 37 had very severe COPD. Levels of CRP (mg/dl) (mean ± standard error [SE]) in moderate, severe, and very severe COPD were 0.60 ± 0.096, 2.16 ± 0.39, and 4.15 ± 0.463, respectively. Levels of prealbumin (mg/dl) (mean ± SE) in moderate, severe, and very severe COPD were 15.7 3 ± 0.92, 10.95 ± 0.85, and 11.15 ± 0.79 mg/dl, respectively. Levels of leptin (ng/ml) (mean ± SE) in moderate, severe, and very severe COPD were 13.81 ± 3.88, 8.45 ± 2.25, and 4.40 ± 1.06, respectively. BMI values in the three groups were 23.44 ± 1.16 kg/m², 20.33 ± 0.62 kg/m², and 18.86 ± 0.52 kg/m², respectively. Sum of four skinfold thickness and MUAC was significantly reduced in very severe group as compared to moderate and severe group. Very severe COPD patients had a significantly lower leptin, BMI, and 6-min walk test. Serum CRP was significantly higher in very severe COPD.

Conclusion

Patients with increasing severity of COPD had a significantly greater serum inflammatory marker level and poorer nutritional status.

Effects of acupuncture on nutritional state of patients with stable chronic obstructive pulmonary disease (COPD): re-analysis of COPD acupuncture trial, a randomized controlled trial

BACKGROUND

There are an increasing number of evidences that chronic obstructive pulmonary disease (COPD) is a systemic illness and that bodyweight loss is its prominent manifestation. We focused on the nutritional outcomes to find out the effectiveness of acupuncture on nutritional state of COPD patients and on their prognosis in our previous interventional study.

METHODS

The present study is re-analysis of our previous interventional study, COPD Acupuncture Trial (CAT) published in 2012. Data from CAT was re-analyzed in terms of nutritional status, inflammatory biomarkers, and prognostic index. Nutritional states were evaluated by the measurements of body weight, body composition, and muscle strength, and the nutritional hematological examination results (retinol-binding protein (RBP), prealbumin (PA), transferrin (Tf), and hemoglobin (Hb) in serum), and inflammation biomarkers such as carboxyhemoglobin (COHb), High sensitivity C-reactive protein (Hs-CRP), Tumor Necrosis Factor-alpha (TNF-α), Interleukin 6 (IL-6), and Serum Amyloid A (SAA) were measured. The BODE index was measured in terms of prognosis. These measurements were compared between the real acupuncture group (RAG) and the placebo acupuncture group (PAG). All data are presented as mean (SD) or mean (95% CI). The difference between baseline and final volumes was compared using analysis of covariance (ANCOVA). Moreover, correlations between nutritional hematological examination scores and inflammation biomarker parameters were assessed using Spearman's rank correlation coefficient.

RESULTS

After 12 weeks, the change in body weight was significantly greater in the RAG compared with the PAG (mean [SD] difference from baseline: 2.5 [0.4] in RAG vs - 0.5 [1.4] in PAG; mean difference between the groups: 3.00, 95% CI, 2.00 to 4.00 with ANCOVA). Patients in RAG also had improvements in the results of nutritional hematological examination (RBP, PA, Tf, Hb), Inflammation biomarkers (TNF-α, IL-6, SAA, Hs-CRP, COHb) and the BODE index.

CONCLUSION

This study demonstrated some clear evidences that acupuncture can be a useful adjunctive therapy to improve nutritional state of COPD patients.

TRIAL REGISTRATION

UMIN Clinical Trials Registry ( UMIN000001277 ). Retrospectively registered.

Difference in systemic inflammation and predictors of acute exacerbation between smoking-associated COPD and tuberculosis-associated COPD

Purpose

Tuberculosis-associated COPD (T-COPD) has clinical characteristics similar to those of smoking-associated COPD (S-COPD), such as dyspnea, sputum production, and acute exacerbation (AE). However, the degree of systemic inflammation and prognosis might be different because of difference in the pathophysiology. The aim of this study was to compare the lung function, systemic inflammatory markers, and their impacts on AE in patients with S-COPD and T-COPD.

Patients and methods

We performed a multicenter cross-sectional cohort study. We evaluated clinical characteristics, pulmonary function tests, levels of inflammatory markers, including C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and IL-6, and the association of these markers with AE in patients with S-COPD and T-COPD.

Results

Patients with T-COPD included more women and had lesser smoking history and higher St George Respiratory Questionnaire score than did patients with S-COPD. Although the FEV₁ of both groups was similar, FVC, vital capacity, total lung capacity, and functional residual capacity were lower in patients with T-COPD than in those with S-COPD. CRP, ESR, and IL-6 levels were significantly higher in patients with T-COPD compared to patients with S-COPD. According to a multivariate logistic regression analysis, FEV₁ was a significant factor predicting AE in S-COPD, and IL-6 was a significant factor predicting AE in T-COPD. IL-6 level greater than 2.04 pg/mL was a cutoff for predicting exacerbation of T-COPD (sensitivity 84.8%, specificity 59.3%, P<0.001).

Conclusion

Patients with T-COPD have higher levels of inflammatory markers, and IL-6 has a predictive value for AE in T-COPD.

Relationship of acid-base status with arterial stiffness in community-living elders: the Health ABC Study

Background

Animal studies suggest that acidosis protects against arterial calcification, which contributes to arterial stiffness. The goal of this study was to investigate the associations of serum bicarbonate and pH with arterial stiffness in community-living older adults.

Methods

We performed cross-sectional analyses among 1698 well-functioning participants 70-79 years of age. Bicarbonate and pH were measured by arterialized venous blood gas at the point of care. Bicarbonate was categorized into low (<23 mEq/L), normal (23-27.9) and high (≥28). Arterialized venous pH (AVpH) was categorized into tertiles: ≤7.40, >7.40-7.42 and >7.42. Arterial stiffness was evaluated by pulse wave velocity (PWV) and high ankle-brachial index (ABI; >1.3/incompressible). We used linear and logistic regression to evaluate the association of bicarbonate and AVpH with PWV and high ABI, respectively.

Results

The mean age was 76 years and 15% had an estimated glomerular filtration rate (eGFR)  <60 mL/min/1.73 m2. The mean bicarbonate was 25.2 ± 2.1 mEq/L and the mean AVpH was 7.41 ± 0.03. Compared with participants in the normal bicarbonate category, those in the low bicarbonate group had 8.8% higher PWV (P = 0.006) and 1.87 greater odds of high ABI (P = 0.04). However, the associations were not significant after adjusting for eGFR (P = 0.24 and 0.43, respectively). There was no difference in PWV or high ABI across AVpH tertiles. Results were similar in those with and without chronic kidney disease and after excluding participants on diuretics.

Conclusions

We did not observe an independent association of bicarbonate or AVpH with arterial stiffness measured by high PWV or ABI in community-living older individuals. Future studies evaluating patients with a greater severity of chronic kidney disease and with more extreme alterations in acid-base status are warranted.

Muscle plasticity of aged subjects in response to electrical stimulation training and inversion and/or limitation of the sarcopenic process

This review addresses the possible structural and functional adaptations of the muscle function to neuromuscular electrical stimulation (NMES) training in frail and/or aged (without advanced chronic disease) subjects. Evidence suggests that the sarcopenic process and its structural and functional effects would be limited and/or reversed through NMES training using excito-motor currents (or direct currents). From a structural viewpoint, NMES helps reduce muscle atrophy. From a functional viewpoint, NMES enables the improvement of motor output (i.e., muscle strength), gait, balance and activities of daily living which enhances the quality of life of aged subjects. Muscle plasticity of aged subjects in response to NMES training turns out to be undeniable, although many mechanisms are not yet explained and deserve to be explore further. Mechanistic explanations as well as conceptual models are proposed to explain how muscle plasticity operates in aged subjects through NMES training. NMES could be seen as a clinically applicable training technique, safe and efficient among aged subjects and could be used more often as part of prevention of sarcopenia. Therapists and physical conditioners/trainers could exploit this new knowledge in their professional practice to improve life conditions (including the risk of fall) of frail and/or aged subjects.

Declining Pulmonary Function in Populations with Long-term Exposure to Polycyclic Aromatic Hydrocarbons-Enriched PM2.5

This study assesses the effects of long-term exposure to ambient air pollutants on inflammatory response and lung function. We selected 390 male coke oven workers with exposure to polycyclic aromatic hydrocarbons (PAHs) and fine particulate matter (PM_2.5) and 115 control workers. The average duration in the exposed group was 9.10 years. The total amount of PAHs was more enriched in PM_2.5 which collected from the coke oven workshops compared with the control areas. Correspondingly, the internal PAHs exposure indicated by urinary 1-hydroxypyrene (1-OHP) in the exposure group increased 25.7-fold compared to that of the control group. Moreover, the increasing level of urinary 1-OHP was associated with the decrease of forced expiratory volume in 1 s to forced vital capacity ratio (FEV₁/FVC). In non-current smokers of exposure group, inverse correlation of 1-OHP with FEV₁/FVC was also found. Particularly, an exposure duration-dependent decline in FEV₁/FVC and mean forced expiratory flow between 25% and 75% of forced vital capacity (FEF_25-75%) indicated that small airways were functionally obstructed. Furthermore, the increasing serum high-sensitivity C-reactive protein (hs-CRP) was correlated with the decline in pulmonary function in all subjects. These findings provide a clue that long-term exposure to PAHs-enriched PM_2.5 impairs pulmonary function in occupational population.

Gender difference in the effects of interleukin-6 on grip strength - a systematic review and meta-analysis

Background

Aging sarcopenia characterized by low muscle mass with low muscle strength affects men and women differently. The contribution of interleukin-6 (IL-6) to sarcopenia has been suggested based on a negative correlation between plasma IL-6 and muscle function described by some studies. However, no consensus regarding clinically relevant cut-off criteria has been reached. Another question arises whether pooling male and female data is an accurate way to determine the predictive value of IL-6 in sarcopenia. The present meta-analysis was designed to assess: (1) whether plasma IL-6 in aged populations in fact correlates negatively to muscle strength; (2) whether such a correlation exists both in men and in women; and (3) whether plasma IL-6 shows a gender difference in old age.

Methods

We applied the preferred reporting items for systematic review and meta-analysis protocols (PRISMA). We searched PubMed and Embase for papers that reported data on individuals over 65 without inflammatory diseases. We extracted either separate male and female data on plasma IL-6 along with at least one muscle parameter or correlation coefficient between plasma IL-6 and these parameters. Random effect models calculated with DerSimonian and Laird weighting methods were applied to analyze correlation coefficients and gender difference in plasma IL-6. Egger’s test was used to assess the small study effect.

Results

Twenty articles out of 468 records identified were suitable for analyses. Plasma IL-6 correlates negatively with grip strength in mixed populations and also separately in men [− 0.25 with 95% confidence interval (CI): − 0.48, − 0.02] and in women (− 0.14 with 95% CI: − 0.24, − 0.03). However, contrary to expectations, men with better muscle condition have higher plasma IL-6 than women of similar age with worse muscle condition (plasma IL-6 male–female difference: 0.25 pg/mL with 95% CI: 0.15, 0.35).

Conclusion

This is the first study to demonstrate that a higher predictive IL-6 cut-off level should be determined for aging sarcopenia in men than in women.

Electronic supplementary material

The online version of this article (10.1186/s12877-018-0798-z) contains supplementary material, which is available to authorized users.

Neglected areas on thorax computed tomography evaluation in patients with chronic obstructive pulmonary disease: Paravertebral muscles and para-aortic adipose tissue

INTRODUCTION

This study, investigated the para-aortic adipose tissue cross-sectional area, a novel predictor of cardiovascular diseases and degenerative changes in the paravertebral muscles, in patients with chronic obstructive pulmonary disease (COPD).

METHOD

One hundred cases diagnosed as COPD and 50 healthy individuals with similar demographic characteristics were evaluated. Para-aortic adipose tissue cross-sectional area (mm2 ), subcutaneous adipose tissue thickness (mm), paravertebral muscle area (mm2 ) and fat deposition in muscle tissue were assessed radiologically.

RESULTS

Paravertebral muscle mass was lower in the patient group compared to the healthy individuals (471.41 ± 157.71 mm2 and 561.58 + 151.03 mm2 , respectively; P = 0.001). Paravertebral muscle attenuation values were also lower in the patient group, and the grade of deposition increased (P = 0.012 and P = 0.045, respectively). Although subcutaneous adipose tissue thicknesses were similar in the patient and control groups, para-aortic adipose tissue cross-sectional area was higher in the patients with COPD than in the control group (439.34 ± 267.17 mm2 and 333.82 ± 165.23 mm2 , respectively, P = 0.012). The correlation between subcutaneous adipose tissue and para-aortic adipose tissue observed in the healthy group was not present in the subjects with COPD.

CONCLUSION

Chronic obstructive pulmonary disease causes morphological changes in paravertebral muscles and para-aortic adipose tissue. Degenerative changes in the paravertebral muscles occur secondary to systemic inflammation, comorbidity and drugs used in COPD. Factors such as insulin resistance and steroid use result in an increase in para-aortic adipose tissue mass.

Breathlessness and inflammation: potential relationships and implications

PURPOSE OF REVIEW

Breathlessness and chronic inflammation both span a wide range of disease contexts and hold prognostic significance. The possibility of a causal relationship between the two has been hypothesized. The aims of this article are to review the intersections between breathlessness and inflammation in the literature, describe potential mechanisms connecting the two phenomena, and discuss the potential clinical implications of a causal relationship.

RECENT FINDINGS

There is a very limited literature exploring the relationship between systemic inflammation and breathlessness in chronic obstructive pulmonary disease, heart failure, and cancer. One large study in cancer patients is suggestive of a weak association between self-reported breathlessness and inflammation. Studies exploring the relationship between inflammation and Medical Research Council Dyspnoea grade in chronic obstructive pulmonary disease patients have produced inconsistent findings. Although a causal relationship has not yet been proven, there is evidence to support the existence of potential mechanisms mediating a relationship. This evidence points to a role for the skeletal muscle and stress hormone systems.

SUMMARY

There is much progress to be made in this area. Interventional studies, evaluating the impact of anti-inflammatory interventions on breathlessness, are needed to help determine whether a causal relationship exists. If proven, this relationship might have important implications for both the treatment and impact of breathlessness.

Association of Adiponectin with Lung Function Impairment and Disease Severity in Chronic Obstructive Pulmonary Disease

Context:

Chronic obstructive pulmonary disease (COPD) is not only restricted to the pulmonary inflammation and airway obstruction but is also associated with comorbidities, which affect the therapeutic intervention and the quality of life and survival. Markers that can predict the systemic inflammation and a decline in the pulmonary function are of scientific interest. Adiponectin (APN) appears to be one such biomarker and can be used as a potential indicator of severity and response to treatment in patients of COPD.

Aims:

The study aims to find out the role of APN as a marker of inflammation in the pathogenesis of COPD and explore its relationship with the severity of the disease.

Settings and Design:

This was a cross-sectional study.

Subjects and Methods:

The study group consisted of 60 patients of COPD, which included 30 males admitted with acute exacerbation of COPD (AECOPD) and 30 males with stable COPD. The study group was compared with 30 healthy, age-matched males. APN was estimated by commercially available ELISA kits. Pulmonary function tests were performed on all cases and controls using standardized protocols on SPIROLAB III.

Statistical Analysis Used:

Statistical analysis was performed using Student's t-test and Pearson's correlation coefficient.

Results:

The levels of APN were found to be significantly higher in patients with COPD as compared to the controls and the levels increased with the severity of the disease were 16.10 ± 4.97 ng/ml and 11.43 ± 4.22 ng/ml, respectively, in AECOPD and COPD. A significant positive correlation was found between the levels of APN and interleukin (IL)-8 in patients of COPD, while the levels correlated negatively with percentage of forced expiratory volume in 1 s (FEV1%).

Conclusions:

The results reveal that APN is associated with the inflammatory process of COPD as suggested by its significant inverse relationship with FEV1% and positive correlation with a marker of inflammation such as IL-8. It can thus be used as a biomarker for disease severity and progression in patients of COPD, therefore aiding in risk stratification and therapeutic intervention.

Elevated serum levels of lipoprotein‑associated phospholipase A2 predict mortality rates in patients with sepsis

Sepsis remains one of the leading contributors to mortality rates in the intensive care unit (ICU) and emergency intensive care unit (EICU). Therefore, any treatments against the agents which produce sepsis in a medical emergency, are welcome. Elevated serum levels of lipoprotein‑associated phospholipase A2 (Lp‑PLA2) have been reported in a small cohort of patients with inflammation. The present study evaluated serum levels of Lp‑PLA2 in patients with sepsis and investigated the role of Lp‑PLA2 in sepsis. The investigation involved the selection of 151 patients with sepsis admitted to the emergency department of the Affiliated Hospital of Nantong University (Nantong, China) and 30 healthy controls. All patients (39 with sepsis, 55 with severe sepsis and 57 with septic shock) were examined on admission to the EICU. A complete blood count was performed, and serum levels of Lp‑PLA2, C‑reactive protein, procalcitonin, and interleukin 6, sequential organ failure (SOFA) scores and Acute Physiology and Chronic Health Evaluation II (APACHE II) scores were determined on hospital admission. The EICU and overall mortality rates were evaluated at baseline. The present study also assessed various laboratory parameters, clinical data and inflammatory cytokines. The patient follow up duration was 90 days. The data suggested that the serum levels of Lp‑PLA2 on admission to the EICU in patients with sepsis were elevated, compared with those in healthy controls. The concentrations of Lp‑PLA2 were correlated with the severity of disease, and were significantly associated with experimental markers of inflammation and established prognostic scores. In the total cohort, persistently elevated levels of Lp‑PLA2 on admission for EICU treatment was a predictor of poor prognosis, and provided superior diagnostic use, compared with the prognostic scoring systems, including SOFA or APACHE II scores. Taken together, the results suggested that Lp‑PLA2, with respect to other markers of inflammation, may have a role as a prognostic marker in sepsis, and provide background evidence for further trials to evaluate the clinical and pathophysiologic roles of Lp‑PLA2 in sepsis. Persistently elevated serum concentrations of Lp‑PLA2 indicated an unfavorable outcome in patients with sepsis. In addition, the results indicated the potential role of Lp‑PLA2 as a prognostic biomarker in patients with sepsis during the early course of EICU treatment.

Severity of COPD and its relationship with IL-10

BACKGROUND

The present study was designed to compare inflammatory and metabolic responses according to severity of airflow among patients with COPD and to verify the relationship between pulmonary function, body composition, metabolic and inflammatory profile.

METHODS

Fifty-one patients with mild to very severe COPD were recruited and divided according lung function in Mild-moderate (GOLD 1-2) n= 21; Severe (GOLD 3) n=25 and Very severe (GOLD 4) n=5. Patients were submitted to assessments of lung function (spirometry), functional exercise capacity (6-min walk test), body composition (Octopolar bioelectrical impedance), metabolic profile (glucose, triglycerides, total cholesterol, HDL-cholesterol and albumin (colorimetric assay)) and inflammatory profile (cytokines: IL-6, IL-10, TNF-α and IL-15 (ELISA)).

RESULTS

We found that patients in GOLD 3 group had lower levels of IL-10, triglycerides, visceral fat area, and higher IL-6 and IL-6/IL-10 ratio when compared to GOLD 1-2 patients. Additionally, GOLD 1-2 group presented negative correlation between TNF-α and HDL cholesterol (p= .01) and positive correlation between IL-15 and FEV₁/FVC (p=.01), while GOLD 3 group showed positive correlation between IL-6 and IL-10 (p< .01), IL-6 and total cholesterol (p<.01) and negative correlation between IL-10 and HDL-cholesterol (p=.01).

CONCLUSION

Our findings suggest that patients with severe COPD can exhibit compromised "inflammatory status", characterized by higher IL6, IL-6/IL-10 ratio and lower IL-10 concentration. Furthermore, IL-10 seems to be an interesting cytokine to be investigated in this kind of patients.

The value of blood cytokines and chemokines in assessing COPD

BACKGROUND

Blood biomarkers are increasingly used to stratify high risk chronic obstructive pulmonary disease (COPD) patients; however, there are fewer studies that have investigated multiple biomarkers and replicated in multiple large well-characterized cohorts of susceptible current and former smokers.

METHODS

We used two MSD multiplex panels to measure 9 cytokines and chemokines in 2123 subjects from COPDGene and 1117 subjects from SPIROMICS. These biomarkers included: interleukin (IL)-2, IL-6, IL-8, IL-10, tumor necrosis factor (TNF)-α, interferon (IFN)-γ, eotaxin/CCL-11, eotaxin-3/CCL-26, and thymus and activation-regulated chemokine (TARC)/CCL-17. Regression models adjusted for clinical covariates were used to determine which biomarkers were associated with the following COPD phenotypes: airflow obstruction (forced expiratory flow at 1 s (FEV1%) and FEV1/forced vital capacity (FEV1/FVC), chronic bronchitis, COPD exacerbations, and emphysema. Biomarker-genotype associations were assessed by genome-wide association of single nucleotide polymorphisms (SNPs).

RESULTS

Eotaxin and IL-6 were strongly associated with airflow obstruction and accounted for 3-5% of the measurement variance on top of clinical variables. IL-6 was associated with progressive airflow obstruction over 5 years and both IL-6 and IL-8 were associated with progressive emphysema over 5 years. None of the biomarkers were consistently associated with chronic bronchitis or COPD exacerbations. We identified one novel SNP (rs9302690 SNP) that was associated with CCL17 plasma measurements.

CONCLUSION

When assessing smoking related pulmonary disease, biomarkers of inflammation such as IL-2, IL-6, IL-8, and eotaxin may add additional modest predictive value on top of clinical variables alone.

TRIAL REGISTRATION

COPDGene (ClinicalTrials.gov Identifier: NCT02445183 ). Subpopulations and Intermediate Outcomes Measures in COPD Study (SPIROMICS) ( ClinicalTrials.gov Identifier: NCT 01969344 ).

C-Reactive Protein Concentrations Among Crop and Dairy Farmers with Stable Chronic Obstructive Pulmonary Disease

AIM

To assess the mean serum C-reactive protein concentrations among farmers and office controls, and further examined its relation to exposure duration, smoking habit, as well as presence or absence of COPD.

METHODS

A cross-sectional survey was performed including examined group (EG), composed of agricultural workers (87 crop - EG1 and 83 dairy farmers - EG2), and control group (CG) composed by 80 office workers. Evaluation of subjects included a questionnaire on chronic respiratory symptoms, lung function tests, COPD diagnostics, and measurement of CRP serum concentrations.

RESULTS

Serum CRP concentrations were raised in stable COPD patients independent of smoking habit or exposure duration. The mean CRP serum concentrations were higher in the subjects of EG1 and EG2 compared with those in CG, but without statistical significance. This count for mean CRP serum concentrations in subjects of EG1 and EG2 exposed more than 20 years and for those in smokers in all three groups as well. The mean CRP serum concentrations were significantly higher in subjects with COPD within EG1 (P=0.049) and EG2 (P=0.040), while those in CG were not.

CONCLUSION

Data obtained suggest that systemic inflammation is present in farmers with COPD and CRP is an important biomarker in COPD in means of reflecting disease severity and prognosis of exposed farmers.

FEV1 and FVC and systemic inflammation in a spinal cord injury cohort

Background

Systemic inflammation has been associated with reduced pulmonary function in individuals with and without chronic medical conditions. Individuals with chronic spinal cord injury (SCI) have clinical characteristics that promote systemic inflammation and also have reduced pulmonary function. We sought to assess the associations between biomarkers of systemic inflammation with pulmonary function in a chronic SCI cohort, adjusting for other potential confounding factors.

Methods

Participants (n = 311) provided a blood sample, completed a respiratory health questionnaire, and underwent spirometry. Linear regression methods were used to assess cross-sectional associations between plasma C-reactive protein (CRP) and interleukin-6 (IL-6) with forced expiratory volume in one second (FEV₁), forced vital capacity (FVC), and FEV₁/FVC.

Results

There were statistically significant inverse relationships between plasma CRP and IL-6 assessed in quartiles or continuously with FEV₁ and FVC. In fully adjusted models, each interquartile range (5.91 mg/L) increase in CRP was associated with a significant decrease in FEV₁ (−55.85 ml; 95% CI: -89.21, −22.49) and decrease in FVC (−65.50 ml; 95% CI: -106.61, −24.60). There were similar significant findings for IL-6. There were no statistically significant associations observed with FEV₁/FVC.

Conclusion

Plasma CRP and IL-6 in individuals with chronic SCI are inversely associated with FEV₁ and FVC, independent of SCI level and severity of injury, BMI, and other covariates. This finding suggests that systemic inflammation associated with chronic SCI may contribute to reduced pulmonary function.

Electronic supplementary material

The online version of this article (doi:10.1186/s12890-017-0459-6) contains supplementary material, which is available to authorized users.

Analysis of the influence of respiratory disorders observed in preoperative spirometry on the dynamics of early inflammatory response in patients undergoing isolated coronary artery bypass grafting

Background

Preoperative spirometry provides measurable information about the occurrence of respiratory disorders. The aim of this study was to assess the association between preoperative spirometry abnormalities and the intensification of early inflammatory responses in patients following coronary artery bypass graft in extracorporeal circulation.

Material and methods

The study involved 810 patients (625 men and 185 women) aged 65.4±7.9 years who were awaiting isolated coronary artery bypass surgery. On the basis of spirometry performed on the day of admittance to the hospital, the patients were divided into three groups. Patients without respiratory problems constituted 78.8% of the entire group. Restricted breathing was revealed by spirometry in 14.9% and obstructive breathing in 6.3% of patients.

Results

Inter-group analysis showed statistically significant differences in C-reactive protein (CRP) between patients with restrictive spirometry abnormalities and patients without any pulmonary dysfunction. CRP concentrations differed before surgery (P=0.006) and on the second (P<0.001), fourth (P=0.005) and sixth days after surgery (P=0.029). There was a negative correlation between CRP levels and FEV₁.

Conclusion

In our study, the most common pulmonary disorders in the coronary artery bypass graft patients were restrictive. Patients with abnormal spirometry results from restrictive respiratory disorders have an elevated level of generalized inflammatory response both before and after the isolated coronary artery bypass surgery. Therefore, this group of patients should be given special postoperative monitoring and, in particular, intensive respiratory rehabilitation immediately after reconstitution.

Exercise training decreases NADPH oxidase activity and restores skeletal muscle mass in heart failure rats

We have recently demonstrated that NADPH oxidase hyperactivity, NF-κB activation, and increased p38 phosphorylation lead to atrophy of glycolytic muscle in heart failure (HF). Aerobic exercise training (AET) is an efficient strategy to counteract skeletal muscle atrophy in this syndrome. Therefore, we tested whether AET would regulate muscle redox balance and protein degradation by decreasing NADPH oxidase hyperactivity and reestablishing NF-κB signaling, p38 phosphorylation, and proteasome activity in plantaris muscle of myocardial infarcted-induced HF (MI) rats. Thirty-two male Wistar rats underwent MI or fictitious surgery (SHAM) and were randomly assigned into untrained (UNT) and trained (T; 8 wk of AET on treadmill) groups. AET prevented HF signals and skeletal muscle atrophy in MI-T, which showed an improved exercise tolerance, attenuated cardiac dysfunction and increased plantaris fiber cross-sectional area. To verify the role of inflammation and redox imbalance in triggering protein degradation, circulating TNF-α levels, NADPH oxidase profile, NF-κB signaling, p38 protein levels, and proteasome activity were assessed. MI-T showed a reduced TNF-α levels, NADPH oxidase activity, and Nox2 mRNA expression toward SHAM-UNT levels. The rescue of NADPH oxidase activity induced by AET in MI rats was paralleled by reducing nuclear binding activity of the NF-κB, p38 phosphorylation, atrogin-1, mRNA levels, and 26S chymotrypsin-like proteasome activity. Taken together our data provide evidence for AET improving plantaris redox homeostasis in HF associated with a decreased NADPH oxidase, redox-sensitive proteins activation, and proteasome hyperactivity further preventing atrophy. These data reinforce the role of AET as an efficient therapy for muscle wasting in HF.

NEW & NOTEWORTHY This study demonstrates, for the first time, the contribution of aerobic exercise training (AET) in decreasing muscle NADPH oxidase activity associated with reduced reactive oxygen species production and systemic inflammation, which diminish NF-κB overactivation, p38 phosphorylation, and ubiquitin proteasome system hyperactivity. These molecular changes counteract plantaris atrophy in trained myocardial infarction-induced heart failure rats. Our data provide new evidence into how AET may regulate protein degradation and thus prevent skeletal muscle atrophy.