Dysregulated adipokine metabolism in chronic obstructive pulmonary disease

Performance of Continuous Glucose Monitoring in Patients With Acute Respiratory Failure: A Prospective, Single-Center Observational Study

OBJECTIVE

Continuous glucose monitoring (CGM) may have benefits in achieving glycemic control in critically ill patients. The aim of this study was to assess the accuracy of the Freestyle Libre H (professional version similar to the Libre Pro) in patients with acute respiratory failure (ARF) in the intensive care unit (ICU).

METHODS

Fifty-two adult patients with ARF were selected. The performance of CGM was evaluated using the arterial blood glucose (aBG) and point-of-care (POC) glucose levels as the reference values. Numerical accuracy was evaluated by the mean absolute relative difference, Bland-Altman analysis, %15/15 (the percentage of CGM values within 15 mg/dL or 15% of reference values <100 or >100 mg/dL, respectively), %20/20, and %30/30. Clinical accuracy was assessed using the Clarke error grid analysis.

RESULTS

A total of 519 and 1504 pairs of aBG/CGM and POC/CGM glucose values were analyzed. The mean absolute relative difference values were 13.8% and 14.7%, respectively. The mean deviations of the Bland-Altman analysis were 0.82 mmol/L and 0.81 mmol/L. The proportions of CGM values within %15/15, %20/20, and %30/30 of the aBG values were 62.6%, 75.5%, and 92.4%, respectively; those within %15/15, %20/20, and %30/30 of the POC values were 57.1%, 72.9%, and 88.7%, respectively. The Clarke error grid analysis showed that 97.8% and 99.3% of the values were located in zone A + B. Additionally, the accuracy of CGM was not affected by general patient factors.

CONCLUSION

This study demonstrated that the accuracy of CGM in patients with ARF is lower than that in most outpatients and it is not affected by general patient factors. Whether CGM is beneficial to glucose management in the intensive care unit needs further evaluation.

Lung function and the risk of frailty in the European population: a mendelian randomization study

BACKGROUND

Epidemiological evidence has suggested a relationship between lung function and frailty, but the precise nature of the causality remains unclear. In this study, we applied a two-sample Mendelian randomization (MR) analysis to determine the causal effects of lung function on frailty.

METHODS

Single nucleotide polymorphisms (SNPs) independently related (P ≤ 5E-08) to lung function, as identified by genome-wide association study (GWAS), were applied as instrumental variables (IV). The association with frailty index (FI) was investigated using summary-level data from the latest GWAS on FI (n = 175,226). Different statistical methods were employed to evaluate the causal estimates between lung function and FI. The pleiotropy, heterogeneity, and leave-one-out analysis were applied to confirm the stability of the MR estimates.

RESULTS

Using the random-effect inverse-variance weighted approach, genetically proxied forced expiratory volume in the first second (FEV1), ratio of FEV1 on forced vital capacity (FVC) [FEV1/FVC], and peak expiratory flow (PEF) were significantly and inversely associated with FI (FEV1, β = -0.08, P = 2.03E-05; FEV1/FVC, β = -0.06, P = 9.51E-06; PEF, β = -0.07, P = 4.09E-04) with good statistical power (99.7-100%). However, no significant association was observed between FVC and FI (β = -0.01, P = 0.681). Leave-one-out analysis showed that there was no single SNP driving the bias of the estimates. There was potential heterogeneity, but no obvious pleiotropy was founded in this MR study.

CONCLUSIONS

Our findings indicate that impaired pulmonary function is closely related to the risk of frailty. Enhancing lung function in the elderly population may contribute to the prevention of frailty to a certain extent.

Relationship between chronic obstructive pulmonary disease and adiponectin concentrations: An updated meta-analysis and single-cell RNA sequencing

BACKGROUND

Adipose tissue, being an organ of the endocrine system, can influence the severity of chronic obstructive pulmonary disease (COPD). Even though several inflammatory markers can potentially significantly influence lung function, the precise function of adipokines, like adiponectin, in COPD is still disputed. To analyze the association of COPD with adiponectin concentrations, a meta-analysis of the most recent literature and single-cell sequencing data were conducted.

METHODS

Studies in Embase, PubMed, Cochrane Library, and Web of Science were browsed to obtain relevant data, which were then assessed with the aid of R 4.1.3 and STATA 11.0 software. Standardized mean differences and correlation coefficients aided the analysis of effect values. Moreover, a single-cell sequencing GSE136831 dataset was retrieved to ascertain the mRNA expression of adiponectin gene (ADIPOQ) in the lung tissue of COPD patients to confirm the difference in the expression of adiponectin between the case and control groups.

RESULTS

This meta-analysis comprised 18 publications involving 24 studies. The overall combined data established the concentration of plasma/serum adiponectin as significantly higher in patients with COPD compared to healthy subjects. Subgroup analyses based on disease status, specimen type, ethnicity, study design method, measurement method, and age of COPD patients demonstrated that all patients with COPD had elevated levels of adiponectin compared to healthy controls. When subgroup analysis was performed for gender alone, the results depicted that male COPD patients had significantly higher adiponectin than healthy males, while female patients of COPD had elevated adiponectin compared to healthy females. Furthermore, it was found that plasma/serum adiponectin appeared to be positively correlated with tumor necrosis factor-α, and it was negatively correlated with FEV1% and FEV1/FVC. The results of single-cell sequencing data suggested that ADIPOQ mRNA was mainly expressed in alveolar epithelial cells, and the level of ADIPOQ mRNA was higher in lung tissues of patients with COPD than in lung tissues of healthy subjects.

CONCLUSION

This meta-analysis suggests that the levels of plasma/serum adiponectin are significantly elevated in patients with COPD versus controls. Tumor necrosis factor-α, FEV1/FVC, and FEV1% may all be associated with the concentrations of adiponectin.

Novel Applications of Biomarkers in Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is an important health problem and an increasing cause of morbidity and mortality worldwide. Currently, COPD is considered a multisystem disease. Although it primarily affects the lungs, structural and functional changes occur in other organs due to systemic inflammation. It is stated that in patients with COPD, airway and systemic inflammatory markers are increased and that these markers are high are associated with a faster decline in lung functions. In recent years, numerous articles have been published on the discovery and evaluation of biomarkers in COPD. Many markers have also been studied to accurately assess COPD exacerbations and provide effective treatment. However, based on the evidence from published studies, a single molecule has not been adequately validated for broad clinical use.

Clustering-based COPD subtypes have distinct longitudinal outcomes and multi-omics biomarkers

Introduction

Chronic obstructive pulmonary disease (COPD) can progress across several domains, complicating the identification of the determinants of disease progression. In our previous work, we applied k-means clustering to spirometric and chest radiological measures to identify four COPD-related subtypes: ‘relatively resistant smokers (RRS)’, ‘mild upper lobe-predominant emphysema (ULE)’, ‘airway-predominant disease (AD)’ and ‘severe emphysema (SE)’. In the current study, we examined the associations of these subtypes to longitudinal COPD-related health measures as well as blood transcriptomic and plasma proteomic biomarkers.

Methods

We included 8266 non-Hispanic white and African-American smokers from the COPDGene study. We used linear regression to investigate cluster associations to 5-year prospective changes in spirometric and radiological measures and to gene expression and protein levels. We used Cox-proportional hazard test to test for cluster associations to prospective exacerbations, comorbidities and mortality.

Results

The RRS, ULE, AD and SE clusters represented 39%, 15%, 26% and 20% of the studied cohort at baseline, respectively. The SE cluster had the greatest 5-year FEV₁ (forced expiratory volume in 1 s) and emphysema progression, and the highest risks of exacerbations, cardiovascular disease and mortality. The AD cluster had the highest diabetes risk. After adjustments, only the SE cluster had an elevated respiratory mortality risk, while the ULE, AD and SE clusters had elevated all-cause mortality risks. These clusters also demonstrated differential protein and gene expression biomarker associations, mostly related to inflammatory and immune processes.

Conclusion

COPD k-means subtypes demonstrate varying rates of disease progression, prospective comorbidities, mortality and associations to transcriptomic and proteomic biomarkers. These findings emphasise the clinical and biological relevance of these subtypes, which call for more study for translation into clinical practice.

Trail registration number

NCT00608764.

Synthesis of Ziziphus spina-christi (Jujube) Root Methanol Extract Loaded Functionalized Silver Nanoparticle (ZS-Ag-NPs); Physiochemical Characterization and Effect of ZS-Ag-NPs on Adipocyte Maturation, Adipokine and Vascular Smooth Muscle Cell Interaction

In this research, a simple, green approach was employed to synthesize silver nanoparticles with the aid of Ziziphus spina-christi (L.) methanol root extract, which can act as a reducing, capping agent to treat obesity and inflammation. Globally, Ziziphus spina-christi (Jujube) root is used in traditional therapy as a lipolysis promoter. GC-MS results confirmed the availability of kaempferol (flavonol), cannabinol and indole-3-carboxylic acid in Ziziphus spina-christi root methanol extract (ZSE). ZSE silver nanoparticles (ZS-Ag-NPs) were synthesized and their effect on mitochondrial fatty acid oxidation capacity and adipokine levels in maturing adipocytes were analyzed. Maturing adipocytes treated with 0.4 µg/dL of ZSE and ZS-Ag-NPs significantly reduced the lipid content in adipocytes by 64% and 82%, respectively. In addition, lipolysis-related genes such as LPL (1.9 fold), HSL (2.3 fold), PGC-1α (3 fold), UCP-1 (4.1 fold), PRDM16 (2 fold) and PPARα (2.7 fold) increased significantly in ZS-Ag-NPs treated maturing adipocytes. The ZS-Ag-NPs treatment significantly decreased insulin resistance and metabolic inflammation-related LTB4-R, TNF-α, IL-4 and STAT-6 mRNA levels. Mitochondrial thermogenesis stimulating capacity of ZS-Ag-NPs was further confirmed by the significantly enhanced CREB-1 and AMPK protein levels in adipocytes. Furthermore, ZS-Ag-NPs treated adipokines (condition media, CM) were treated with human umbilical vein endothelial cells (HUVECs) to determine cytotoxicity and pro-inflammatory stimulus capacity. We found that ZS-Ag-NPs treated adipocyte CM effectively increased mRNA expression levels of the vascular endothelial cell growth factor (VEGF), and down-regulated oxidative stress (LPO, eNOS, and HO) and vascular cell inflammation (ICAM, VCAM, TNF-α, IL-1β, and NF-κB). In conclusion, ZS-Ag-NPs displayed an action at the molecular level in mitochondrial fatty acid oxidation, decreased adipokine secretion in adipocytes, and enhanced vascular endothelial cell growth. This molecular mechanical action of ZS-Ag-NPs reduced effectively obesity progressions and metabolic inflammatory pathogenesis associated with aging.

Association between serum adiponectin concentrations and chronic obstructive pulmonary disease: a meta-analysis

Background: Adiponectin has been implicated to play a role in the pathophysiology of chronic obstructive pulmonary disease (COPD). Many studies have assessed serum adiponectin concentrations in COPD patients. However, results from different reports were not consistent. To assess the association of serum adiponectin concentrations and COPD, a meta-analysis was performed.

Methods: PubMed, Embase, Web of Science and Cochrane Library were searched for eligible studies. Data were extracted, and then standard mean differences (SMDs) and 95% confidence intervals (CI) were calculated.

Results: Thirteen studies involving a total of 1131 cases and 689 controls were included in this meta-analysis. Combined data indicated that the serum adiponectin levels were higher in COPD patients than those in controls (SMD: 1.09, 95% CI [0.73–1.45], P < 0.001). In the subgroup analyses by disease period, there were similar results in stable COPD patients (SMD: 0.77, 95% CI [0.47–1.07], p <0.001; I² = 83.9%, P < 0.001), AECOPD patients (SMD: 2.51, 95% CI [0.71–4.30], P = 0.006; I² = 95.2%, P < 0.001) and mixed COPD patients (SMD: 1.21, 95% CI [0.67–1.75], P < 0.001). Furthermore, the serum adiponectin levels were higher in AECOPD patients than those in stable COPD patients (SMD: 1.06, 95% CI [0.13–1.99], P = 0.026).

Conclusions: This meta-analysis indicates that patients with COPD have higher serum adiponectin concentration than healthy controls.

Serum Leptin in Hospitalized Community-Acquired Pneumonia Children under the Age of Five Years

Background

Community-acquired pneumonia (CAP) accounts for 19% of the world’s total deaths among all age groups yearly, with highest rates in children less than 5 years. This study is designed to evaluate the serum leptin level in hospitalized children under the age of 5 years with CAP.

Results

This prospective cross-sectional study included CAP children under the age of 5 years. Forty-one patients admitted to pediatric intensive care unit (PICU) and 41 patients admitted to general ward were enrolled. Patients with any other cause that may elevate serum leptin were excluded. Serum leptin was measured on the day of admission. The PICU patients had a significantly higher median serum leptin than that of the ward patients (p < 0.001). C-reactive protein (CRP) level was significantly higher in patients with elevated serum leptin than in patients with normal serum leptin (p = 0.001). There was a significant association between high serum leptin and positive sputum cultures (p < 0.001), particularly cultures growing more than one organism (p < 0.001). There was a positive, weak correlation between serum leptin and length of stay (r = 0.30, p = 0.007). Serum leptin showed good discrimination between PICU admissions and inpatient ward admissions (AUC = 0.777, p < 0.001); at a cut-off value of > 29.6 pg/ml, serum leptin had a sensitivity of 70.7% and a specificity of 87.8%

Conclusion

We may conclude that CAP patients with a serum leptin level above 29.6 pg/ml should be considered for PICU admission.

Chronic hypoxaemia and gender status modulate adiponectin plasmatic level and its multimer proportion in severe COPD patients: new endotypic presentation?

BACKGROUND

Disease progression in COPD patient is associated to lung function decline, leading to a higher risk of hypoxaemia and associated comorbidities, notably cardiovascular diseases (CVD). Adiponectin (Ad) is an adipokine with cardio-protective properties. In COPD patients, conflicting results were previously reported regarding Ad plasmatic (Adpl) level, probably because COPD is a heterogeneous disease with multifactorial influence. Among these factors, gender and hypoxaemia could interact in a variety of ways with Ad pathway. Therefore, we postulated that these components could influence Adpl level and its multimers in COPD patients and contribute to the appearance of a distinct endotype associated to an altered CVD risk.

METHODS

One hundred COPD patients were recruited: 61 were men and 39 were women. Patients who were not severely hypoxemic were allocated to non-hypoxemic group which included 46 patients: 27 men and 19 women. Hypoxemic group included 54 patients: 34 men and 20 women. For all patients, Adpl level and proportion of its different forms were measured. Differences between groups were evaluated by Rank-Sum tests. The relationship between these measures and BMI, blood gas analysis (PaO2, PaCO2), or lung function (FEV1, FEV1/FVC, TLCO, TLC, RV) were evaluated by Pearson correlation analysis.

RESULTS

Despite similar age, BMI and obstruction severity, women had a higher TLC and RV (median: TLC = 105%; RV = 166%) than men (median: TLC = 87%; RV = 132%). Adpl level was higher in women (median = 11,152 ng/ml) than in men (median = 10,239 ng/ml) and was negatively associated with hyperinflation (R = - 0,43) and hypercapnia (R = - 0,42). The proportion of the most active forms of Ad (HMW) was increased in hypoxemic women (median = 10%) compared with non-hypoxemic women (median = 8%) but was not modulated in men.

CONCLUSION

COPD pathophysiology seemed to be different in hypoxemic women and was associated to Ad modulations. Hyperinflation and air-trapping in association with hypercapnia and hypoxaemia, could contribute to a modulation of Adpl level and of its HMW forms. These results suggest the development of a distinct endotypic presentation, based on gender.

Malnutrition, Health and the Role of Machine Learning in Clinical Setting

Nutrition plays a vital role in health and the recovery process. Deficiencies in macronutrients and micronutrients can impact the development and progression of various disorders. However, malnutrition screening tools and their utility in the clinical setting remain largely understudied. In this study, we summarize the importance of nutritional adequacy and its association with neurological, cardiovascular, and immune-related disorders. We also examine general and specific malnutrition assessment tools utilized in healthcare settings. Since the implementation of the screening process in 2016, malnutrition data from hospitalized patients in the Geisinger Health System is presented and discussed as a case study. Clinical data from five Geisinger hospitals shows that ~10% of all admitted patients are acknowledged for having some form of nutritional deficiency, from which about 60-80% of the patients are targeted for a more comprehensive assessment. Finally, we conclude that with a reflection on how technological advances, specifically machine learning-based algorithms, can be integrated into electronic health records to provide decision support system to care providers in the identification and management of patients at higher risk of malnutrition.

Frailty in the End-Stage Lung Disease or Heart Failure Patient: Implications for the Perioperative Transplant Clinician

The syndrome of frailty for patients undergoing heart or lung transplantation has been a recent focus for perioperative clinicians because of its association with postoperative complications and poor outcomes. Patients with end-stage cardiac or pulmonary failure may be under consideration for heart or lung transplantation along with bridging therapies such as ventricular assist device implantation or venovenous extracorporeal membrane oxygenation, respectively. Early identification of frail patients in an attempt to modify the risk of postoperative morbidity and mortality has become an important area of study over the last decade. Many quantification tools and risk prediction models for frailty have been developed but have not been evaluated extensively or standardized in the cardiothoracic transplant candidate population. Heightened awareness of frailty, coupled with a better understanding of distinct cellular mechanisms and biomarkers apart from end-stage organ disease, may play an important role in potentially reversing frailty related to organ failure. Furthermore, the clinical management of these critically ill patients may be enhanced by waitlist and postoperative physical rehabilitation and nutritional optimization.

Lung, Fat and Bone: Increased Adiponectin Associates with the Combination of Smoking-Related Lung Disease and Osteoporosis

Background: Adiponectin has been proposed as a biomarker of disease severity and progression in chronic obstructive pulmonary disease (COPD) and associated with spirometry-defined COPD and with computed tomography (CT)-measured emphysema. Increased adiponectin plays a role in other diseases including diabetes/metabolic syndrome, cardiovascular disease and osteoporosis. Previous studies of adiponectin and COPD have not assessed the relationship of adiponectin to airway disease in smokers and have not evaluated the effect of other comorbid diseases on the relationship of adiponectin and lung disease. We postulated that adiponectin levels would associate with both airway disease and emphysema in smokers with and without COPD, and further postulated that body composition and the comorbid diseases of osteoporosis, cardiovascular disease and diabetes might influence adiponectin levels. Methods: Current and former smokers from the COPD Genetic Epidemiology study (COPDGene) (n= 424) were assigned to 4 groups based on CT lung characteristics and volumetric Bone Density (vBMD). Emphysema (% low attenuation area at -950) and airway disease (Wall area %) were used to assess smoking-related lung disease (SRLD). Group 1) Normal Lung with Normal vBMD; Group 2) Normal Lung and Osteoporosis; Group 3) SRLD with Normal vBMD; Group 4) SRLD with Osteoporosis. Cardiovascular disease (CVD), diabetes, C-reactive protein (CRP) and T-cadherin (soluble receptor for adiponectin) levels were defined for each group. Body composition was derived from chest CT. Multivariable regression assessed effects of emphysema, wall area %, bone density, comorbid diseases and other key factors on log adiponectin. Results: Group 4, SRLD with Osteoporosis, had significantly higher adiponectin levels compared to other groups and the effect persisted in adjusted models. Systemic inflammation (by CRP) was associated with SRLD in Groups 3 and 4 but not with osteoporosis alone. In regression models, lower bone density and worse emphysema were associated with higher adiponectin. Airway disease was associated with higher adiponectin levels when T-cadherin was added to the model. Male gender, greater muscle and fat were associated with lower adiponectin. Conclusions: Adiponectin is increased with both airway disease and emphysema in smokers. Bone density, and fat and muscle composition are all significant factors predicting adiponectin that should be considered when it is used as a biomarker of COPD. Increased adiponectin from chronic inflammation may play a role in the progression of bone loss in COPD and other lung diseases.

The revised GOLD 2017 COPD categorization in relation to comorbidities

INTRODUCTION

The COPD classification proposed by the Global Initiative for Obstructive Lung Disease was recently revised, and the A to D grouping is now based on symptoms and exacerbations only. Potential associations with comorbidities have not been assessed so far. Thus the aim of the present study was to determine the relationship between the revised (2017) GOLD groups A-D and major comorbidities.

METHODS

We used baseline data from the COPD cohort COSYCONET. Comorbidities were identified from patient self-reports and disease-specific medication: gastrointestinal disorders, asthma, sleep apnea, hyperuricemia, hyperlipidemia, diabetes, osteoporosis, mental disorders, heart failure, hypertension, coronary artery disease. The A-D groups were based on either the COPD Assessment Test or the modified Medical Research Council scale. Exacerbations were also categorized as per GOLD recommendations.

RESULTS

Data from 2228 patients were analyzed. Using GOLD group A as a reference, group D was associated with nearly all comorbidities, followed by group B and C. When groups A-D were dichotomized as AC vs. BD (symptoms) and AB vs. CD (exacerbations), all comorbidities correlated with symptoms and/or exacerbations. This was true for both mMRC- and CAT-based categorizations.

CONCLUSIONS

These findings suggest that the recently modified GOLD categorization is clinically relevant beyond being purely an assessment of symptoms and exacerbations. As the A-D groups correlated with the risk of important comorbidities, with some differences in terms of the correlation with symptoms and exacerbations, the findings underline the importance of identifying comorbidities in COPD, particularly in non-responders to therapy who have high symptoms and/or exacerbation rates.

Metabolic Disorder in Chronic Obstructive Pulmonary Disease (COPD) Patients: Towards a Personalized Approach Using Marine Drug Derivatives

Metabolic disorder has been frequently observed in chronic obstructive pulmonary disease (COPD) patients. However, the exact correlation between obesity, which is a complex metabolic disorder, and COPD remains controversial. The current study summarizes a variety of drugs from marine sources that have anti-obesity effects and proposed potential mechanisms by which lung function can be modulated with the anti-obesity activity. Considering the similar mechanism, such as inflammation, shared between obesity and COPD, the study suggests that marine derivatives that act on the adipose tissues to reduce inflammation may provide beneficial therapeutic effects in COPD subjects with high body mass index (BMI).

Evaluation of plasma leptin, tumor necrosis factor-α, and prealbumin as prognostic biomarkers during clinical recovery from acute exacerbations of chronic obstructive pulmonary disease

BACKGROUND

Inflammatory and nutritional biomarkers have an important bearing on outcomes of acute exacerbations of chronic obstructive pulmonary disease (AECOPD), but the temporal profile of these compounds during an acute episode is unclear.

PATIENTS AND METHODS

Plasma leptin, prealbumin, and tumor necrosis factor-alpha (TNF-α) were estimated at baseline and before hospital discharge in patients with AECOPD.

RESULTS

A total of 82 patients were evaluated (66 males; mean (standard deviation) age, 61.6 (10.1) years. Of these, 74 subjects (90.2%) were current or former smokers, with median (range) pack-years of 15 (0-96), duration of COPD of 8 years (range, 2-25 years) and duration of current symptoms being 5 days (range, 1-30 days). Majority (41.5%) had type I (severe) exacerbation. During the current episode, 46 patients (58.9%) required mechanical ventilation for a median of 6 days (range, 1-34). The median duration of hospital stay was 13 days, (range, 1-110). At discharge, significant reduction was observed in dyspnea, total leukocyte count, erythrocyte sedimentation rate (ESR), partial pressure of carbon dioxide, hemoglobin, urea, creatinine, potassium, aspartate transferase, and TNF-α levels compared to baseline, whereas arterial pH, PO₂, serum albumin, prealbumin, and leptin significantly improved. No difference was seen in leptin, prealbumin, and TNF-α between patients with mild/moderate and severe exacerbation, or between patients who required or did not require mechanical ventilation. Change in leptin correlated with body mass index and change in ESR; no associations were observed between leptin, prealbumin, and TNF-α with other clinico-laboratory variables.

CONCLUSION

Plasma levels of novel inflammatory and nutritional biomarkers, i.e., leptin, TNF-α, and prealbumin are altered in AECOPD episodes and lag behind other parameters during recovery. These biomarkers are not reliable predictors of clinical outcomes in these patients.

Evaluation of body composition in COPD patients using multifrequency bioelectrical impedance analysis

Background

Multifrequency bioelectrical impedance analysis (MF-BIA) is a technique that measures body impedance (Z) at different frequencies (5, 10, 50, 100, and 250 kHz). Body composition may be estimated using empirical equations, which include BIA variables or, alternatively, raw BIA data may provide direct information on water distribution and muscle quality.

Objectives

To compare raw MF-BIA data between COPD patients and controls and to study their relationship with respiratory and functional parameters in COPD patients.

Methods

MF-BIA was performed (Human Im-Touch analyzer) in 212 COPD patients and 115 age- and BMI-matched controls. Fat-free mass (FFM) and fat mass were estimated from BIA data, and low- to high-frequency (5 kHz/250 kHz) impedance ratio was calculated. Physical fitness, lung function and respiratory muscle strength were also assessed in COPD patients.

Results

After adjusting for age, weight, and body mass index, FFM and the 5/250 impedance ratio were lower in COPD patients (P<0.001) and were negatively affected by disease severity. In both male and female patients, the 5/250 impedance ratio was significantly correlated mainly with age (r=−0.316 and r=−0.346, respectively). Patients with a 5/250 impedance ratio below median value had lower handgrip strength (P<0.001), 6-minute walk distance (P<0.005), respiratory muscle strength (P<0.005), forced expiratory volume in 1 second (P<0.05) and vital capacity (P<0.005). Finally, the 5/250 impedance ratio was reduced (P<0.05) in patients with Global Initiative for Chronic Obstructive Lung Disease (GOLD) III and IV (compared to those with GOLD I and II) or a BODE index between 6 and 10 points (compared to those with BODE index between 1 and 5 points).

Conclusion

MF-BIA may be a useful tool for assessing body composition and nutritional status in COPD patients. In particular, the impedance ratio could give valuable information on cellular integrity and muscle quality.

Frailty in Pulmonary and Critical Care Medicine

Conceptualized first in the field of geriatrics, frailty is a syndrome characterized by a generalized vulnerability to stressors resulting from an accumulation of physiologic deficits across multiple interrelated systems. This accumulation of deficits results in poorer functional status and disability. Frailty is a "state of risk" for subsequent disproportionate declines in health status following new exposure to a physiologic stressor. Two predominant models have emerged to operationalize the measurement of frailty. The phenotype model defines frailty as a distinct clinical syndrome that includes conceptual domains such as strength, activity, wasting, and mobility. The cumulative deficit model defines frailty by enumerating the number of age-related things wrong with a person. The biological pathways driving frailty include chronic systemic inflammation, sarcopenia, and neuroendocrine dysregulation, among others. In adults with chronic lung disease, frailty is independently associated with more frequent exacerbations of lung disease, all-cause hospitalization, declines in functional status, and all-cause mortality. In addition, frail adults who become critically ill are more likely develop chronic critical illness or severe disability and have higher in-hospital and long-term mortality rates. The evaluation of frailty appears to provide important prognostic information above and beyond routinely collected measures in adults with chronic lung disease and the critically ill. The study of frailty in these populations, however, requires multipronged efforts aimed at refining clinical assessments, understanding the mechanisms, and developing therapeutic interventions.

Hyperlipidemia in COPD is associated with decreased incidence of pneumonia and mortality: a nationwide health insurance data-based retrospective cohort study

PURPOSE

COPD is often associated with various comorbidities that may influence its outcomes. Pneumonia, cardiovascular disease (CVD), and cancer are the major causes of death in COPD patients. The objective of this study is to investigate the influence of comorbidities on COPD by using the Taiwan National Health Insurance database.

PATIENTS AND METHODS

We retrospectively analyzed the database in 2006 of one million sampling cohort. Newly diagnosed patients with COPD with a controlled cohort that was matched by age, sex, and Charlson comorbidity index (CCI) were included for analysis.

RESULTS

In total, 1,491 patients with COPD were included for analysis (61.8% male). Patients with COPD had higher incidences of pneumonia (25.7% vs 10.4%; P<0.0001), CVD (15.1% vs 10.5%; P<0.0001), and mortality rate (26.6% vs 15.8%; P<0.001) compared with the control group in the 4-year follow-up. In patients with COPD, CCI ≥3 have a higher incidence of pneumonia (hazard ratio [HR] 1.61; 95% confidence interval [CI] 1.23-2.09; P<0.0001), CVD (HR 1.73; 95% CI 1.24-2.41; P=0.001), and mortality (HR 1.12; 95% CI 1.12-1.83; P=0.004). Among the major comorbidities of COPD, hyperlipidemia was associated with decreased incidence of pneumonia (HR 0.68; 95% CI 0.5-0.93; P=0.016) and mortality (HR 0.64; 95% CI 0.46-0.90; P=0.009), but was not associated with increased risk of CVD (HR 1.10; 95% CI 0.78-1.55; P=0.588).

CONCLUSION

Our results demonstrate that COPD is associated with increased incidence of pneumonia, CVD, and mortality. In patients with COPD, higher CCI is associated with increased incidence of pneumonia, CVD, and mortality. However, COPD with hyperlipidemia is associated with decreased incidence of pneumonia and mortality.

Frailty Phenotypes, Disability, and Outcomes in Adult Candidates for Lung Transplantation

RATIONALE

Frailty is associated with morbidity and mortality in abdominal organ transplantation but has not been examined in lung transplantation.

OBJECTIVES

To examine the construct and predictive validity of frailty phenotypes in lung transplant candidates.

METHODS

In a multicenter prospective cohort, we measured frailty with the Fried Frailty Phenotype (FFP) and Short Physical Performance Battery (SPPB). We evaluated construct validity through comparisons with conceptually related factors. In a nested case-control study of frail and nonfrail subjects, we measured serum IL-6, tumor necrosis factor receptor 1, insulin-like growth factor I, and leptin. We estimated the association between frailty and disability using the Lung Transplant Valued Life Activities disability scale. We estimated the association between frailty and risk of delisting or death before transplant using multivariate logistic and Cox models, respectively.

MEASUREMENTS AND MAIN RESULTS

Of 395 subjects, 354 completed FFP assessments and 262 completed SPPB assessments; 28% were frail by FFP (95% confidence interval [CI], 24-33%) and 10% based on the SPPB (95% CI, 7-14%). By either measure, frailty correlated more strongly with exercise capacity and grip strength than with lung function. Frail subjects tended to have higher plasma IL-6 and tumor necrosis factor receptor 1 and lower insulin-like growth factor I and leptin. Frailty by either measure was associated with greater disability. After adjusting for age, sex, diagnosis, and transplant center, both FFP and SPPB were associated with increased risk of delisting or death before lung transplant. For every 1-point worsening in score, hazard ratios were 1.30 (95% CI, 1.01-1.67) for FFP and 1.53 (95% CI, 1.19-1.59) for SPPB.

CONCLUSIONS

Frailty is prevalent among lung transplant candidates and is independently associated with greater disability and an increased risk of delisting or death.

Pharmacological effects of lysozyme on COPD and bronchial asthma with sputum: A randomized, placebo-controlled, small cohort, cross-over study

BACKGROUND

Mucolytic agents are often used in Japan to ease excessive mucus production in patients with chronic obstructive pulmonary disease (COPD) or bronchial asthma (BA); the treatment ameliorates dyspnea and improves quality of life (QOL).

AIM

Efficacy and safety of lysozyme hydrochloride (LYS), an oral mucolytic enzyme preparation, for patients with COPD or BA were investigated.

PATIENTS AND METHODS

This study was a placebo-controlled, double-blind, randomized, cross-over design. Twenty-four patients with COPD and twenty-four patients with BA were enrolled. LYS or placebo was administered for 28 days in each treatment period, with a 28-day washout between the first and second treatment periods. The results of spirometry, impulse oscillometry system (IOS) examination, fractional exhaled nitric oxide (FeNO) measurement, as well as the changes in the subjective symptoms, were evaluated after the treatment period.

RESULTS

On spirometry, airway function (FEV1) improved in patients with COPD after administration of LYS (LYS vs placebo: 0.08 L vs 0.029 L, p = 0.030). Similar trends were also found in %FEV1 in COPD patients. On IOS examination, resistance of the respiratory system at 5 Hz levels was significantly improved only in patients with COPD (LYS vs placebo: -0.455 cm H2O/L/s vs 0.095 cmH2O/L/s, p = 0.012). Similar trends were found in terms of the resistance of the respiratory system at 20 Hz, and of the reactance area. In the COPD assessment test, subjective symptoms also significantly improved in patients with COPD during the LYS treatment period (improvement rates-LYS vs. placebo: 69.6% vs. 39.1%; p = 0.022). A similar effect of LYS was not seen in BA patients.

CONCLUSION

LYS, a mucolytic agent, has capability to improve the function of peripheral airways in patients with COPD, which leads to improvements of the patients' symptoms and QOL.

Glucose Levels in Patients With Acute Respiratory Failure Requiring Mechanical Ventilation

BACKGROUND

Recent studies suggest that patients with acute exacerbations of chronic obstructive pulmonary disease (COPD) frequently develop hyperglycemia, which has been linked to adverse outcomes.

METHODS

We retrospectively collected information about patient demographics, admission diagnosis, comorbidities, use of insulin, and glucose levels and related tests in 174 patients who required mechanical ventilation for acute respiratory failure.

RESULTS

These patients had a mean age of 57.8 ± 16.8 years, a mean Acute Physiology and Chronic Health Evaluation (APACHE II) score of 13.8 ± 6.1, and an overall mortality of 32.2%. The mean number of ventilator days was 7.5 ± 7.1. The mean highest glucose level was 239.3 ± 88.9 mg/dL in patients with COPD (n = 41) and 259.1 ± 131.7 mg/dL in patients without COPD (n =133). Patients with diabetes had higher glucose levels than patients without this diagnosis ( P < .05). Patients receiving corticosteroids did not have increased glucose levels ( P > .05). The mortality rate was higher in patients with glucose levels >140 mg/dL than in patients below 140 mg/dL (35.1% vs 10.5%, P < .05 unadjusted analysis).

CONCLUSION

In this study, hyperglycemia occurred in 89% of the patients with acute respiratory failure requiring mechanical ventilation. The most important risk factor for this was a premorbid diagnosis of diabetes.

Challenges and Current Efforts in the Development of Biomarkers for Chronic Inflammatory and Remodeling Conditions of the Lungs

This review discusses biomarkers that are being researched for their usefulness to phenotype chronic inflammatory lung diseases that cause remodeling of the lung's architecture. The review focuses on asthma, chronic obstructive pulmonary disease (COPD), and pulmonary hypertension. Bio-markers of environmental exposure and specific classes of biomarkers (noncoding RNA, metabolism, vitamin, coagulation, and microbiome related) are also discussed. Examples of biomarkers that are in clinical use, biomarkers that are under development, and biomarkers that are still in the research phase are discussed. We chose to present examples of the research in biomarker development by diseases, because asthma, COPD, and pulmonary hypertension are distinct entities, although they clearly share processes of inflammation and remodeling.

Chronic obstructive pulmonary disease and the metabolic syndrome: Consequences of a dual threat

The metabolic syndrome is found to be more frequent in chronic obstructive pulmonary disease (COPD). The presence of inflammatory markers in circulation, sputum, and broncho-alveolar fluid suggest systemic inflammation is one of the potential mechanisms responsible for both COPD and metabolic syndrome. Physical inactivity, skeletal muscle dysfunction, hypogonadism, and steroid use are also important causes of the metabolic syndrome in COPD. Obesity and insulin resistance is found to be more common in mild to moderate stages (I and II) of COPD. Patients with COPD and the metabolic syndrome have increase risk of morbidity and mortality due to cardiovascular disease. This review describes in details the various components of metabolic syndrome and its impact on long outcomes in COPD patients.

Association between plasma adiponectin levels and decline in forced expiratory volume in 1 s in a general Japanese population: the Takahata study

BACKGROUND

Adiponectin is an anti-inflammatory and cardio-protective cytokine. However, several studies have demonstrated that plasma adiponectin levels were inversely associated with pulmonary function in patients with chronic obstructive pulmonary disease, suggesting a proinflammatory or pulmonary-destructive role. It is still unclear whether adiponectin is a potent biomarker predicting declines in pulmonary function. The aim of this study was to investigate the association between adiponectin and pulmonary function among Japanese individuals who participated in an annual health check-up.

METHODS

Spirometry and blood sampling, including measurements of plasma adiponectin, were performed for 3,253 subjects aged 40 years or older who participated in a community-based annual health check-up in Takahata, Japan from 2004 to 2006. In 2011, spirometry was re-performed, and the data from 872 subjects (405 men and 467 women) were available for a longitudinal analysis.

RESULTS

Plasma adiponectin levels were found to be significantly associated with age, body mass index (BMI), and alanine aminotransferase (ALT), triglycerides (TG), and high-density lipoprotein-cholesterol (HDL-c) levels among both men and women in the study population. Plasma adiponectin levels were found to be associated with lifetime cigarette consumption (Brinkman index, BI) in men only. Plasma adiponectin levels were inversely correlated with forced expiratory volume in 1 s (FEV1) per forced vital capacity in both men and women. In addition, the annual change in FEV1 was inversely associated with plasma adiponectin levels in both genders. A multiple linear regression analysis revealed that this association was independent of other confounding factors such as age, BMI, BI, ALT, TG, and HDL-c.

CONCLUSIONS

The results of the present study suggest that adiponectin levels are predictive of declines in FEV1 in the general population.

Lungs, bone marrow, and adipose tissue. A network approach to the pathobiology of chronic obstructive pulmonary disease

Patients with chronic obstructive pulmonary disease (COPD) often suffer other concomitant disorders, such as cardiovascular diseases and metabolic disorders, that influence significantly (and independently of lung function) their health status and prognosis. Thus, COPD is not a single organ condition, and disturbances of a complex network of interorgan connected responses occur and modulate the natural history of the disease. Here, we propose a novel hypothesis that considers a vascularly connected network with (1) the lungs as the main external sensor of the system and a major source of "danger signals"; (2) the endothelium as an internal sensor of the system (also a potential target tissue); and (3) two key responding elements, bone marrow and adipose tissue, which produce both inflammatory and repair signals. According to the model, the development of COPD, and associated multimorbidities (here we focus on cardiovascular disease as an important example), depend on the manner in which the vascular connected network responds, adapts, or fails to adapt (dictated by the genetic and epigenetic background of the individual) to the inhalation of particles and gases, mainly in cigarette smoke. The caveats and limitations of the hypothesis, as well as the experimental and clinical research needed to test and explore the proposed model, are also briefly discussed.

Lessons from ECLIPSE: a review of COPD biomarkers

The Evaluation of COPD Longitudinally to Identify Predictive Surrogate End-points (ECLIPSE) study was a large 3-year observational controlled multicentre international study aimed at defining clinically relevant subtypes of chronic obstructive pulmonary disease (COPD) and identifying novel biomarkers and genetic factors. So far, the ECLIPSE study has produced more than 50 original publications and 75 communications to international meetings, many of which have significantly influenced our understanding of COPD. However, because there is not one paper reporting the biomarker results of the ECLIPSE study that may serve as a reference for practising clinicians, researchers and healthcare providers from academia, industry and government agencies interested in COPD, we decided to write a review summarising the main biomarker findings in ECLIPSE.

Circulating leptin concentrations in patients with chronic obstructive pulmonary disease: a systematic review and meta-analysis

BACKGROUND

Weight loss is a clinically important risk factor indicating a poor prognosis in chronic obstructive pulmonary disease (COPD). Leptin is an important regulator of food intake and energy expenditure.

OBJECTIVES

To conduct a meta-analysis to determine whether the level of leptin is related to the disease status of COPD.

METHODS

Studies published before December 2012 were identified by searching PubMed, Embase and the Cochrane Database. Observational studies comparing circulating leptin levels between COPD patients and healthy controls were included. Data were independently extracted by two investigators and analyzed using Stata 12.0 software.

RESULTS

Ten articles were included in the meta-analysis. Circulating leptin levels were correlated with the body mass index (BMI) as well as percent fat mass in stable COPD patients. The correlation coefficient tended to be weaker during exacerbation. A positive correlation between leptin and tumor necrosis factor (TNF)-α levels was found in COPD exacerbations, while it disappeared in patients with stable disease. Most studies indicated that circulating leptin levels in stable COPD patients were not significantly different from those in healthy controls when adjusted for gender and BMI, whilst leptin levels tended to elevate in exacerbation groups.

CONCLUSIONS

The normal regulatory mechanism of leptin is maintained in stable COPD patients despite weight loss. The additional correlation between leptin and TNF-α during exacerbations may support the closer association of leptin with changes in nutritional parameters and suggests its valuable role in the evaluation of systemic inflammatory responses in COPD patients during exacerbation, which merits further study.

The association of adiponectin with computed tomography phenotypes in chronic obstructive pulmonary disease

RATIONALE

Chronic obstructive pulmonary disease (COPD) is a heterogeneous disorder associated with systemic manifestations that contribute to its morbidity and mortality. Recent work suggests that biomarker signatures in the blood may be useful in evaluating COPD phenotypes and may provide insight into the pathophysiology of systemic manifestations. Adiponectin, primarily produced by fat cells, has been implicated in the pathophysiology of emphysema.

OBJECTIVES

To investigate the association of adiponectin with clinical and radiologic COPD phenotypes.

METHODS

Adiponectin levels were determined in 633 individuals, including 432 individuals with COPD from a cohort of former or current smokers enrolled in the COPDGene study. Univariate and multiple regression analysis were used to examine the association of adiponectin with clinical and physiologic data together with quantitative high-resolution computed tomography parameters.

MEASUREMENTS AND MAIN RESULTS

Multiple regression analysis confirmed that higher plasma adiponectin levels were independently associated with emphysema, decreasing body mass index, female sex, older age, and lower percentage change in prebronchodilator/post-bronchodilator FEV1.

CONCLUSIONS

The association between plasma adiponectin and computed tomography-assessed emphysema suggests a contribution of adiponectin to the development of emphysema and highlights a role for metabolic derangements in the pathophysiology of emphysema.

Adiponectin is associated with dynamic hyperinflation and a favourable response to inhaled glucocorticoids in patients with COPD

OBJECTIVES

Adipokines are protein mediators first described as products of adipose tissue regulating energy metabolism and appetite. Recently, adipokines have also been found to modulate inflammation and smooth muscle cell responses. Therefore we investigated the association of two adipokines, adiponectin and leptin, with the degree of emphysema, pulmonary function, symptoms and glucocorticoid responsiveness in patients with COPD.

METHODS

Plasma adiponectin and leptin levels, spirometry, body plethysmography and symptoms were measured in 43 male COPD patients with smoking history ≥ 20 pack-years, post bronchodilator FEV1/FVC < 0.7 and pulmonary emphysema on HRCT. The measurements were repeated in a subgroup of patients after 4 weeks' treatment with inhaled fluticasone.

RESULTS

In patients with COPD, plasma adiponectin levels correlated positively with airway resistance (Raw) (r = 0.362, p = 0.019) and functional residual capacity (FRC) (r = 0.355, p = 0.046). Furthermore, the baseline adiponectin concentration correlated negatively with the fluticasone induced changes in St George's Respiratory questionnaire (SGRQ) symptom score (r = -0.413, p = 0.040) and in FRC % pred (r = -0.428, p = 0.003), i.e. a higher baseline plasma adiponectin level was associated with more pronounced alleviation of symptoms and dynamic hyperinflation. Plasma leptin levels were not related to the measures of lung function, symptoms or glucocorticoid responsiveness.

CONCLUSIONS

Plasma adiponectin levels were associated with peripheral airway obstruction and dynamic hyperinflation in patients with COPD. A higher adiponectin level predicted more favourable relief of symptoms and hyperinflation during glucocorticoid treatment. Adiponectin may have a role in the COPD pathogenesis; it may also be a biomarker of disease severity and treatment responses in this disease.

Leptin as regulator of pulmonary immune responses: involvement in respiratory diseases

Leptin is an adipocyte-derived hormone, recognized as a critical mediator of the balance between food intake and energy expenditure by signalling through its functional receptor (Ob-Rb) in the hypothalamus. Structurally, leptin belongs to the long-chain helical cytokine family, and is now known to have pleiotropic functions in both innate and adaptive immunity. The presence of the functional leptin receptor in the lung together with evidence of increased airspace leptin levels arising during pulmonary inflammation, suggests an important role for leptin in lung development, respiratory immune responses and eventually pathogenesis of inflammatory respiratory diseases. The purpose of this article is to review our current understanding of leptin and its functional role on the different resident cell types of the lung in health as well as in the context of three major respiratory conditions being chronic obstructive pulmonary disease (COPD), asthma, and pneumonia.

Chronic obstructive pulmonary disease and glucose metabolism: a bitter sweet symphony

Chronic obstructive pulmonary disease, metabolic syndrome and diabetes mellitus are common and underdiagnosed medical conditions. It was predicted that chronic obstructive pulmonary disease will be the third leading cause of death worldwide by 2020. The healthcare burden of this disease is even greater if we consider the significant impact of chronic obstructive pulmonary disease on the cardiovascular morbidity and mortality. Chronic obstructive pulmonary disease may be considered as a novel risk factor for new onset type 2 diabetes mellitus via multiple pathophysiological alterations such as: inflammation and oxidative stress, insulin resistance, weight gain and alterations in metabolism of adipokines. On the other hand, diabetes may act as an independent factor, negatively affecting pulmonary structure and function. Diabetes is associated with an increased risk of pulmonary infections, disease exacerbations and worsened COPD outcomes. On the top of that, coexistent OSA may increase the risk for type 2 DM in some individuals. The current scientific data necessitate a greater outlook on chronic obstructive pulmonary disease and chronic obstructive pulmonary disease may be viewed as a risk factor for the new onset type 2 diabetes mellitus. Conversely, both types of diabetes mellitus should be viewed as strong contributing factors for the development of obstructive lung disease. Such approach can potentially improve the outcomes and medical control for both conditions, and, thus, decrease the healthcare burden of these major medical problems.