Association between chronic obstructive pulmonary disease and serum lipid levels: a meta-analysis

SCARF2 is a target for chronic obstructive pulmonary disease: Evidence from multi-omics research and cohort validation

Age-related chronic inflammatory lung diseases impose a threat on public health, including idiopathic pulmonary fibrosis (IPF) and chronic obstructive pulmonary disease (COPD). However, their etiology and potential targets have not been clarified. We performed genome-wide meta-analysis for IPF with the largest sample size (2883 cases and 741,929 controls) and leveraged the summary statistics of COPD (17,547 cases and 617,598 controls). Transcriptome-wide and proteome-wide Mendelian randomization (MR) designs, together with genetic colocalization, were implemented to find robust targets. The mediation effect was assessed using leukocyte telomere length (LTL). The single-cell transcriptome analysis was performed to link targets with cell types. Individual-level data from UK Biobank (UKB) were used to validate our findings. Sixteen genetically predicted plasma proteins were causally associated with the risk of IPF and 6 proteins were causally associated with COPD. Therein, genetically-elevated plasma level of SCARF2 protein should reduce the risk of both IPF (odds ratio, OR = 0.9974 [0.9970, 0.9978]) and COPD (OR = 0.7431 [0.6253, 0.8831]) and such effects were not mediated by LTL. Genetic colocalization further corroborated these MR results of SCARF2. The transcriptome-wide MR confirmed that higher expression level of SCARF2 was associated with a reduced risk of both. However, the single-cell RNA analysis indicated that SCARF2 expression level was only relatively lower in epithelial cells of COPD lung tissue compared to normal lung tissue. UKB data implicated an inverse association of serum SCARF2 protein with COPD (hazard ratio, HR = 1.215 [1.106, 1.335]). The SCARF2 gene should be a novel target for COP.

Smoking cessation only partially reverses cardiac metabolic and structural remodeling in mice

AIMS

Active cigarette smoking is a major risk factor for chronic obstructive pulmonary disease that remains elevated after cessation. Skeletal muscle dysfunction has been well documented after smoking, but little is known about cardiac adaptations to cigarette smoking. The underlying cellular and molecular cardiac adaptations, independent of confounding lifestyle factors, and time course of reversibility by smoking cessation remain unclear. We hypothesized that smoking negatively affects cardiac metabolism and induces local inflammation in mice, which do not readily reverse upon 2-week smoking cessation.

METHODS

Mice were exposed to air or cigarette smoke for 14 weeks with or without 1- or 2-week smoke cessation. We measured cardiac mitochondrial respiration by high-resolution respirometry, cardiac mitochondrial density, abundance of mitochondrial supercomplexes by electrophoresis, and capillarization, fibrosis, and macrophage infiltration by immunohistology, and performed cardiac metabolome and lipidome analysis by mass spectrometry.

RESULTS

Mitochondrial protein, supercomplex content, and respiration (all p < 0.03) were lower after smoking, which were largely reversed within 2-week smoking cessation. Metabolome and lipidome analyses revealed alterations in mitochondrial metabolism, a shift from fatty acid to glucose metabolism, which did not revert to control upon smoking cessation. Capillary density was not different after smoking but increased after smoking cessation (p = 0.02). Macrophage infiltration and fibrosis (p < 0.04) were higher after smoking but did not revert to control upon smoking cessation.

CONCLUSIONS

While cigarette-impaired smoking-induced cardiac mitochondrial function was reversed by smoking cessation, the remaining fibrosis and macrophage infiltration may contribute to the increased risk of cardiovascular events after smoking cessation.

Correlation of Parathyroid Hormone Values With Lung Function Parameters in Patients With Chronic Obstructive Pulmonary Disease

OBJECTIVES

The aim of this study was to determine the disturbances in the concentration of parathyroid hormone (PTH) and 25-hydroxyvitamin D (vitamin D) in patients with stable chronic obstructive pulmonary disease (COPD) and its correlation with airflow obstruction.

MATERIALS AND METHODS

A prospective study included 200 patients with a confirmed diagnosis of COPD in the Department of Lung Diseases and Tuberculosis and Pulmonology Polyclinic of University Clinical Hospital Mostar in the period of three years, between May 2021 and May 2024. Inclusion criteria were a stable phase of COPD, hemodynamically stable patients older than 40 years, forced vital capacities in the first second (FEV1)/forced vital capacities (FVC) <0.7, and patients with PTH, vitamin D, calcium, and phosphate measurements. Exclusion criteria were acute exacerbation of COPD in the last month; current treatment with nutritional supplements, vitamins, and statins; lack of availability of lung function data; use of systemic corticosteroids in the previous three months; chronic renal insufficiency, respiratory diseases other than COPD (asthma, pneumonia, tuberculosis, and bronchiectasis), and other diseases (cancer and parathyroid disease). Medical records about demographic data (age and gender), pulmonary function test (FVC, FEV1, FEV1%FVC, mean expiratory flow (MEF)50), body mass index (BMI), COPD assessment test (CAT), Modified Medical Research Council (mMRC) Dyspnea Scale, and serum PTH, vitamin D, calcium, and phosphate levels were obtained.

RESULTS

 Patients with higher COPD stage had lower spirometry values, most significantly MEF50. The higher the COPD group (Global Initiative for Chronic Obstructive Lung Disease (GOLD) D), the lower vitamin D ​​and the higher PTH levels were. Calcium and phosphate values ​​were the same for all groups. Vitamin D and PTH levels significantly ​​correlated with MEF50 values. The lower MEF50 level, the higher PTH levels, ​​and lower vitamin D levels were found (P<0.05).

CONCLUSION

Our study showed that the patients in the higher COPD group have lower vitamin D levels ​​and higher PTH levels, indicating that they developed secondary hyperparathyroidism. The levels of vitamin D and PTH correlated the most with MEF50 values while other spirometry parameters did not significantly correlate with vitamin D and PTH levels.

Subchronic exposure to fenpyroximate causes multiorgan toxicity in Wistar rats by disrupting lipid profile, inducing oxidative stress and DNA damage

BACKGROUND

Fenpyroximate (FEN) is an acaricide that inhibits the complex I of the mitochondrial respiratory chain in mites. Data concerning mammalian toxicity of this acaricide are limited; thus the aim of this work was to explore FEN toxicity on Wistar rats, particularly on cardiac, pulmonary, and splenic tissues and in bone marrow cells.

METHODS

rats were treated orally with FEN at 1, 2, 4, and 8 mg/Kg bw for 28 days. After treatment, we analyzed lipid profile, oxidative stress and DNA damage in rat tissues.

RESULTS

FEN exposure increased creatinine phosphokinase (CPK) and lactate dehydrogenase (LDH) activities, elevated total cholesterol (T-CHOL), triglycerides (TG), and low-density lipoprotein cholesterol (LDL-C) concentrations, while decreasing high-density lipoprotein cholesterol (HDL-C). It inhibited acetylcholinesterase (AChE) activity, enhanced lipid peroxidation, protein oxidation, and modulated antioxidant enzymes activities (superoxide dismutase, catalase, glutathione peroxidase, and glutathione S-transferase). Comet assay indicated that FEN induced a dose-dependent DNA damage, contrasting with the micronucleus test showing no micronuclei formation. Nonetheless, FEN exhibited cytotoxicity to bone marrow cells, as evidenced by a reduction in the number of immature erythrocytes among total cells.

CONCLUSION

FEN appears to carry out its genotoxic and cytotoxic activities most likely through an indirect pathway that involves oxidative stress.

Assessment of Behavioral Risk Factors in Chronic Obstructive Airway Diseases of the Lung Associated with Metabolic Syndrome

BACKGROUND

Diet and lifestyle play important roles in preventing and improving chronic diseases, and evaluating behavioral risk factors in these pathologies allows for efficient management.

METHODS

A clinical study by screening biochemical parameters and pulmonary function was carried out to evaluate behavioral risk factors in obstructive pulmonary disease associated with metabolic syndrome.

RESULTS

Of the total of 70 patients included in the clinical study, 46 were men and 24 were women (χ2 = 3.9, p = 0.168). Forty-eight patients presented at least three met risk criteria associated with the metabolic syndrome (19 women and 29 men). Regarding the assessment of lung function, only 7 of the patients presented normal spirometry values (χ2 = 75.28, p < 0.001), and the other 63 patients presented with ventilatory dysfunction; most (over 80%) declared that they were smokers or had smoked in the past (χ2 = 5.185, p = 0.075). In terms of body weight, 45 of the patients are overweight or obese, most of them declaring that they do not consume enough vegetable products, they consume large amounts of foods of animal origin (meat, milk, eggs) but also super processed foods (food products type of junk food), do not hydrate properly, and are predominantly sedentary people (54 of the patients do no physical activity at all; χ2 = 2.12, p = 0.713).

CONCLUSION

From the statistical processing of the data, it is noted that insufficient hydration, low consumption of vegetables, increased consumption of hyper-caloric food products rich in additives, sedentary lifestyle, and smoking are the main disruptive behavioral factors that worsen the health status in lung disease associated with the metabolic syndrome. An important conclusion emerging from the study is that the imbalances that aggravate obstructive lung diseases are generated by unhealthy food and an unbalanced lifestyle.

Being met as a person and not as a diagnosis - Meanings of healthcare encounters for women with chronic obstructive pulmonary disease stage III or IV

Our study seeks to elucidate meanings of healthcare encounters for women with chronic obstructive pulmonary disease stage III or IV. We conducted 12 narrative interviews which were analyzed using phenomenological hermeneutic interpretation. Our analysis revealed one theme; being met as a person and not as a diagnosis with three subthemes: getting sufficient time and feeling involved in care; fulfillment of personal needs; and experiencing disrespect and injustice. We found that meanings of healthcare encounters center on the expectation of being seen as a person. Feeling disrespected and injust leaves women unsupported and could pose serious health risks.

PathIntegrate: Multivariate modelling approaches for pathway-based multi-omics data integration

As terabytes of multi-omics data are being generated, there is an ever-increasing need for methods facilitating the integration and interpretation of such data. Current multi-omics integration methods typically output lists, clusters, or subnetworks of molecules related to an outcome. Even with expert domain knowledge, discerning the biological processes involved is a time-consuming activity. Here we propose PathIntegrate, a method for integrating multi-omics datasets based on pathways, designed to exploit knowledge of biological systems and thus provide interpretable models for such studies. PathIntegrate employs single-sample pathway analysis to transform multi-omics datasets from the molecular to the pathway-level, and applies a predictive single-view or multi-view model to integrate the data. Model outputs include multi-omics pathways ranked by their contribution to the outcome prediction, the contribution of each omics layer, and the importance of each molecule in a pathway. Using semi-synthetic data we demonstrate the benefit of grouping molecules into pathways to detect signals in low signal-to-noise scenarios, as well as the ability of PathIntegrate to precisely identify important pathways at low effect sizes. Finally, using COPD and COVID-19 data we showcase how PathIntegrate enables convenient integration and interpretation of complex high-dimensional multi-omics datasets. The PathIntegrate Python package is available at https://github.com/cwieder/PathIntegrate.

A Systematic Review on the Association between Schizophrenia and Bipolar Disorder with Chronic Obstructive Pulmonary Disease

A systematic review aimed to investigate the association between schizophrenia and bipolar disorder and chronic obstructive pulmonary disease (COPD), its prevalence and incidence, potential factors associated with its occurrence and its impact on mortality among these patients. We performed the literature search in PubMed, Scopus and PsycInfo from inception to February 2022 and identified 19 studies: ten cross-sectional, 5 that included cross-sectional and longitudinal analyses, and 4 retrospective cohort studies. The reported prevalence of COPD ranged from 2.6% to 52.7% in patients with schizophrenia and between 3.0% and 12.9% in patients with bipolar disorder. Two studies reported an annual incidence of COPD of 2.21 cases/100 person-years in patients with schizophrenia and 2.03 cases/100 person-years in patients with bipolar disorder. Among the risk factors evaluated in three studies, only advanced age was consistently associated with the presence/occurrence of COPD in patients with schizophrenia and bipolar disorder; the role of tobacco consumption was not investigated in those three studies. According to two studies, the likelihood of mortality from COPD showed an over 3-fold increase in patients with schizophrenia and a 2-fold increase in those with bipolar disorder compared to the overall population; COPD was also associated with increased inpatient mortality. Available data indicate that COPD in patients with schizophrenia and bipolar disorder is a major public health problem. National and international health organizations should strive to specifically address this issue by creating awareness about this health problem and developing specific programs for screening and early intervention aimed to reduce the burden of COPD in these populations.

Preserved Ratio Impaired Spirometry, Metabolomics, and the Risk of Type 2 Diabetes

CONTEXT

Whether baseline preserved ratio impaired spirometry (PRISm) is associated with the risk of developing type 2 diabetes (T2D) and if this association could be mediated by circulating metabolites remains to be elucidated.

OBJECTIVE

To measure the prospective association of PRISm with T2D and potential metabolic mediators thereof.

METHODS

This study used data from the UK Biobank and included 72 683 individuals without diabetes at baseline. PRISm was defined as the predicted forced expiratory volume in 1 second (FEV1) <80% and the FEV1/forced vital capacity ratio ≥0.70. Cox proportional hazards modeling was performed to assess the longitudinal relation between baseline PRISm and incident T2D. Mediation analysis was used to explore the mediation effects of circulating metabolites in the path from PRISm to T2D.

RESULTS

During a median follow-up of 12.06 years, 2513 participants developed T2D. Individuals who had PRISm (N = 8394) were 47% (95% CI, 33%-63%) more likely to develop T2D compared with those who had normal spirometry (N = 64 289). A total of 121 metabolites showed statistically significant mediation effects in the path from PRISm to T2D (false discovery rate <0.05). Glycoprotein acetyls, cholesteryl esters in large high-density lipoprotein (HDL), degree of unsaturation, cholesterol in large HDL, and cholesteryl esters in very large HDL were the top 5 metabolic markers, with mediation proportions (95% CI) being 11.91% (8.76%-16.58%), 11.04% (7.34%-15.55%), 10.36% (7.34%-14.71%), 9.87% (6.78%-14.09%), and 9.51% (6.33%-14.05%), respectively. A total of 11 principal components that explained 95% variance of the metabolic signatures accounted for 25.47% (20.83%-32.19%) of the relation between PRISm and T2D.

CONCLUSIONS

Our study revealed the association of PRISm with T2D risk and the potential roles of circulating metabolites in mediating this association.

Quantifying COPD as a risk factor for cardiac disease in a primary prevention cohort

BACKGROUND

Despite COPD being a risk factor for cardiovascular disease (CVD) and knowing that risk stratification for CVD primary prevention is important, little is known about the real-world risk of CVD among people with COPD with no history of CVD. This knowledge would inform CVD management for people with COPD. The current study aimed to examine the risk of major adverse cardiovascular events (MACE) (including acute myocardial infarction, stroke or cardiovascular death) in a large, complete real-world population with COPD without previous CVD.

METHODS

We conducted a retrospective population cohort study using health administrative, medication, laboratory, electronic medical record and other data from Ontario, Canada. People without a history of CVD with and without physician-diagnosed COPD were followed between 2008 and 2016, and cardiac risk factors and comorbidities compared. Sequential cause-specific hazard models adjusting for these factors determined the risk of MACE in people with COPD.

RESULTS

Among ∼5.8 million individuals in Ontario aged ≥40 years without CVD, 152 125 had COPD. After adjustment for cardiovascular risk factors, comorbidities and other variables, the rate of MACE was 25% higher in persons with COPD compared with those without COPD (hazard ratio 1.25, 95% CI 1.23-1.27).

CONCLUSIONS

In a large real-world population without CVD, people with physician-diagnosed COPD were 25% more likely to have a major CVD event, after adjustment for CVD risk and other factors. This rate is comparable to the rate in people with diabetes and calls for more aggressive CVD primary prevention in the COPD population.

Low-density lipoprotein cholesterol and risk of COPD: Copenhagen General Population Study

Background

Randomised controlled trials found that low-density lipoprotein (LDL) cholesterol-lowering statins increase lung function and possibly decrease rate of exacerbations in individuals with COPD. However, it is unknown whether high levels of LDL cholesterol are associated with increased susceptibility to COPD.

Methods

We tested the hypothesis that high LDL cholesterol is associated with increased risk of COPD, severe COPD exacerbation and COPD-specific mortality. We examined 107 301 adults from the Copenhagen General Population Study. COPD outcomes were ascertained at baseline and prospectively through nationwide registries.

Results

In cross-sectional analysis, low LDL cholesterol was associated with increased risk of COPD (odds ratio for 1st versus 4th quartile: 1.07 (95% CI 1.01-1.14)). Prospectively, low LDL cholesterol was associated with increased risk of COPD exacerbations with hazard ratios of 1.43 (1.21-1.70) for 1st versus 4th quartile, 1.21 (1.03-1.43) for 2nd versus 4th quartile, and 1.01 (0.85-1.20) for 3rd versus 4th quartile of LDL cholesterol (p-value for trend=6×10^-6). Finally, low LDL cholesterol was likewise associated with increased risk of COPD-specific mortality (log-rank test: p=0.0009). Sensitivity analyses with death as competing risk provided similar results.

Conclusion

Low LDL cholesterol was associated with increased risks of severe COPD exacerbation and COPD-specific mortality in the Danish general population. As this is opposite of that observed in randomised controlled trials with statins, our findings might be a result of reverse causation indicating that individuals with severe phenotypes of COPD have lower plasma levels of LDL cholesterol due to wasting.

Biomarker-based clustering of patients with chronic obstructive pulmonary disease

Rationale

COPD has been associated repeatedly with single biomarkers of systemic inflammation, ignoring the complexity of inflammatory pathways. This study aimed to cluster patients with COPD based on systemic markers of inflammatory processes and to evaluate differences in their clinical characterisation and examine how these differences may relate to altered biological pathways.

Methods

213 patients with moderate-to-severe COPD in a clinically stable state were recruited and clinically characterised, which included a venous blood sample for analysis of serum biomarkers. Patients were clustered based on the overall similarity in systemic levels of 57 different biomarkers. To determine interactions among the regulated biomarkers, protein networks and biological pathways were examined for each patient cluster.

Results

Four clusters were identified: two clusters with lower biomarker levels (I and II) and two clusters with higher biomarker levels (III and IV), with only a small number of biomarkers with similar trends in expression. Pathway analysis indicated that three of the four clusters were enriched in Rage (receptor for advanced glycation end-products) and Oncostatin M pathway components. Although the degree of airflow limitation was similar, the clinical characterisation of clusters ranged from 1) better functional capacity and health status and fewer comorbidities; 2) more underweight, osteoporosis and static hyperinflation; 3) more metabolically deranged; and 4) older subjects with worse functional capacity and higher comorbidity load.

Conclusions

These new insights may help to understand the functionally relevant inflammatory interactions in the pathophysiology of COPD as a heterogeneous disease.

The association between total cholesterol and cognitive impairment in chronic obstructive pulmonary disease patients

AIM

Chronic obstructive pulmonary disease (COPD) is primarily a respiratory system disorder associated with extrapulmonary conditions. Cognitive impairment (CoI) is very common among COPD patients This study sought to investigate the association between CoI and clinical parameters, inflammatory markers and lipid profiles in a COPD patient population.

METHODS

The study population included 111 stable COPD patients. COPD was diagnosed according to Global Initiative for Chronic Obstructive Lung Disease guideline. Total complete blood count test and biochemical measurements including lipid profile were performed. Afterwards, all patients underwent neuropsychological assessment including Hospital Anxiety and Depression Scale (HADS), Pittsburgh Sleep Quality Index and Montreal Cognitive Assessment (MoCA) tests.

RESULTS

The patients were categorized into two groups according to their MoCA test score: MoCA score ≤ 21 (CoI) (n = 69) and MoCA score > 21 (normal cognition) (n = 42). Total cholesterol (TC) levels were significantly lower in patients with CoI compared to patients with normal cognition. Inflammation related parameters including C-reactive protein were similar among groups. Multivariate logistic regression analysis yielded education, HADS score and TC (OR:1.02, 95% CI:1.00-1.04, p = 0.025) as independent predictors of MoCA score.

CONCLUSION

TC independently associates with CoI in COPD patients. There is comparable inflammatory status in COPD patients with CoI compared to COPD patients with normal cognition.

Hierarchical stratification of the factors related to exertional dyspnoea and exercise intolerance in male COPD patients

BACKGROUND

The order and extent of interactions across the factors affecting exertional dyspnoea (ED) and exercise intolerance (EI) in patients with chronic obstructive pulmonary disease (COPD) are not clear. We hypothesized that lung and non-lung variables were the primary variables, ED was the secondary variable and EI was the tertiary variable.

METHODS

Data on demographics, blood tests, cardiac imaging, lung function tests and invasive dead space fractions (V_D/V_T) during incremental exercise test of 46 male COPD subjects were obtained. These variables were categorized by factor analysis and pair-wise correlation analysis was conducted. The best factor of each category was selected and then multivariate regression was conducted.

RESULTS

Peak tidal inspiratory flow (V_T/T_Ipeak), V_D/V_Tpeak and tidal lung expansion capability, and resting diffusing capacity of the lungs (D_LCO)% predicted were the primary pulmonary factors most related to ED, whereas body mass index (BMI), haemoglobin and cholesterol levels were the primary non-pulmonary factors. In multivariate regression analysis, V_T/T_Ipeak, V_D/V_Tpeak and D_LCO% were the primary factors most related to ED (r² = 0.69); ED was most related to EI (r = -0.74 to -0.83).

CONCLUSION

Using hierarchical stratification and statistical methods may improve understanding of the pathophysiology of ED and EI in patients with COPD. KEY MESSAGESThe pathophysiology of exertional dyspnoea (ED) and exercise intolerance (EI) in chronic obstructive pulmonary disease (COPD) is complex. The order and extent of interactions across factors are not clear. In multivariate regression analysis, we found that tidal inspiratory flow, dead space fraction and resting diffusing capacity of the lungs % but not the non-pulmonary factors affected ED.Using correlation coefficients, we further found that ED was the secondary variable and EI was the tertiary variable.Hierarchical stratification of the important factors associated with ED and EI in patients with COPD clarifies their relationships and could be incorporated into management programmes and outcome studies for these patients.

The Relationship of Low-Density-Lipoprotein to Lymphocyte Ratio with Chronic Obstructive Pulmonary Disease

Background

Chronic Obstructive Pulmonary Disease (COPD) has been a concern all over the world because of its high prevalence and mortality. The ratio of low-density-lipoprotein to lymphocyte (LLR) has been widely used to predict the prognosis of cerebral infarction, but its association with COPD is less known. We aim to explore the relationship between LLR and COPD and to investigate its indicative role in the severity and prognosis of COPD.

Methods

In this study, 279 participants (n = 138 with COPD and n = 138 age- and sex-matched health control) were recruited. COPD patients were divided into two groups according to the optimal cut-off value of LLR determined by the receiver operating characteristic curve (ROC). We collected the clinical characteristics, pulmonary function, LLR, neutrophil–lymphocyte ratio (NLR), platelet–lymphocyte ratio (PLR) and other data of all subjects. t-test, Pearson correlation test, logistic regression analysis and other statistical analysis were carried out.

Results

Compared with the healthy control group, COPD patients had a significantly higher LLR level (p < 0.001). The disease was more serious in the high LLR group, which was reflected by Global Initiative for Chronic Obstructive Lung Disease (GOLD) and BMI, airway obstruction, dyspnoea, severe exacerbations (BODE) index and St. George’s Respiratory Questionnaire (SGRQ) index (p = 0.001, p = 0.013, p = 0.011, respectively). The forced expiration volume in 1 second (FEV₁) (p = 0.033) and forced expiratory volume in 1 second in percent of the predicted value (FEV₁%) (p = 0.009) in high LLR group were lower. Univariate and multivariate logistic regression analysis showed that LLR was an independent factor affecting the severity of COPD patients (odds ratio [OR] = 2.599, 95% CI: 1.266-5.337, p = 0.009).

Conclusion

We found that LLR is a novel biomarker in predicting the severity of patients with COPD. Further studies with larger database were recommended to verify our findings.

High-Density Lipoproteins: A Role in Inflammation in COPD

Chronic obstructive pulmonary disease (COPD) is a widespread disease associated with high rates of disability and mortality. COPD is characterized by chronic inflammation in the bronchi as well as systemic inflammation, which contributes significantly to the clinically heterogeneous course of the disease. Lipid metabolism disorders are common in COPD, being a part of its pathogenesis. High-density lipoproteins (HDLs) are not only involved in lipid metabolism, but are also part of the organism’s immune and antioxidant defense. In addition, HDL is a versatile transport system for endogenous regulatory agents and is also involved in the removal of exogenous substances such as lipopolysaccharide. These functions, as well as information about lipoprotein metabolism disorders in COPD, allow a broader assessment of their role in the pathogenesis of heterogeneous and comorbid course of the disease.

Plasma Lipid Profiling Identifies Phosphatidylcholine 34:3 and Triglyceride 52:3 as Potential Markers Associated with Disease Severity and Oxidative Status in Chronic Obstructive Pulmonary Disease

PURPOSE

To identify plasma alterations in lipid species in patients with chronic obstructive pulmonary disease (COPD), as well as, relationships with smoking status, oxidative and inflammatory markers.

METHODS

Plasma was obtained from 100 patients with COPD and 120 healthy controls. Pulmonary function was assessed by plethysmography. Serum levels of IL-6 and TNF-α were determined by ELISA. Oxidative stress parameters were measured using standard methods. Lipids were extracted then analyzed by Matrix-Assisted Laser Desorption and Ionization Time-Of-Flight Mass Spectrometry (MALDI-TOF-TOF-MS).

RESULTS

More than 40 lipid compounds were identified within plasma samples. Among these 19 lipid species including plasmalogens (PC O-), phosphatidylcholines (PC), and triglycerides (TG) were significantly altered in COPD. A decreased expression of PC O- (36:1, 36:2, 36:3, 36:4, 38:4, 38:5) species was found in patients with different severities compared to healthy controls. There was also a decrease in PC (34:3, 36:0, 36:4, 36:5, 40:6, 40:7) species in COPD patients. PC (34:3) levels were positively correlated with disease progression and pulmonary function decline (forced expiratory volume in 1 s (FEV₁)) (r = 0.84, p < 0.001) and inversely correlated with thiobarbituric acid-reactive substances (TBARS) (r = - 0.77, p < 0.001). TG (50:0, 50:1, 52:1, 52:2, 52:3, 52:4, 54:4) species were altered in COPD patients and in those with advanced disease stages. Significant correlations between FEV₁, TBARS, peroxynitrite, and TG (52:3) were found among COPD patients (r = - 0.69; r = 0.86; r = 0.77, p < 0.001, respectively).

CONCLUSION

PC (34:3) and TG (52:3) could be potential lipid signatures of COPD that correlate with altered pulmonary function and oxidative status.

Possible association of high-density lipoprotein cholesterol levels with trunk muscle deficits and decrease in energy expenditure in patients with or at risk for COPD: A pilot study

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is associated with low muscle mass and function caused by malnutrition and physical inactivity. We aimed to investigate possible associations between serum biomarkers and clinical traits including computed tomography-derived muscle measurements and energy expenditure indices in COPD.

METHODS

Total energy expenditure (TEE) was measured by the doubly labeled water method, while physical activity level (PAL) was calculated as TEE/basal metabolic rate. Cross-sections and densities of pectoralis, rectus abdominis, and erector spinae muscles were measured. Serum biomarkers included adiponectin, insulin-like growth factor-1, and high-density lipoprotein (HDL)- and low-density lipoprotein (LDL)-cholesterol (C).

RESULTS

HDL-C levels were significantly correlated with all muscle areas, densities, and TEE. Only LDL-C levels were correlated with PAL.

CONCLUSIONS

HDL-C level was a potential biomarker for trunk muscle volumes and functions, as well as total energy expenditure in COPD.

Respiratory function correlates with fat mass index and blood triglycerides in institutionalized older individuals

BACKGROUND

We investigated the relationship between respiratory function measured by spirometry analysis and anthropometric variables (skeletal and fat mass) and nutritional status in the institutionalized elderly, particularly at high risk of adverse outcomes after respiratory infections and malnutrition.

DESIGN

A multicenter cross-sectional study with quantitative approach among older people institutionalized living in nursing homes.

METHODS

Respiratory function was assessed by measuring the forced vital capacity, forced expiratory volume in the first second, the ratio between FEV1 and FVC (FEV1/FVC), and peak expiratory flow in percentage by means of spirometric analysis (values of the forced expiratory volume measured during the first second of the forced breath (FEV1) and forced vital capacity (FVC)). Nutritional assessment and anthropometry analysis were done to evaluate under or over nutrition/weight.

RESULTS

There was a significant (p<0.05) and positive correlation between FEV1 and skeletal muscle mass index, whereas fat mass index correlated significantly (p<0.01) with the FEV1/FVC index. FEV1/FVC values were both significantly (p<0.05) associated with high body mass index and triglyceride levels in blood. The prevalence of individuals with ventilator restrictive pattern (FEV1/FVC>70% with FEV1 and FVC<80%) was 27.6% and 12 individuals (21.1%) receive daily bronchodilators as part of the pharmacological treatment for respiratory disorders. A logistic regression was performed to identify predictors of restrictive respiratory pattern. The following variables were entered into the model: age group, female gender, Charlson comorbidity index, body-mass index (BMI), fat mass index, skeletal muscle mass index, total cholesterol and triglycerides concentration. The model was statistically significant (p < 0.05; R2 = 0.39), correctly classifying 70.0% of cases, with a sensitivity of 89.3% and a specificity of 50.0%. Area under curve was 0.71 (IC95% 0.54-0.88; p=0.023). The highest OR for restrictive respiratory pattern were for BMI (OR=5.09) and triglycerides concentration in blood (>150 mg/dl) (OR=5.59).

CONCLUSION

The relationship between a restrictive pattern of respiratory function and fat mass which deserves future investigation to manage these parameters as possible modifiable factor of altered respiratory function in overweight institutionalized older individuals.

Metabolic syndrome in patients with COPD: Causes and pathophysiological consequences

BACKGROUND

Decreased physical activity significantly increases the probability of prevalent metabolic syndrome (MetS) with substantial impact on the expected course of COPD.

OBJECTIVE

Our research aims to assess the metabolic consequences of chronic obstructive pulmonary disease (COPD) and evaluate the prevalence of MetS and its interrelations with age, sex, comorbidities, drug intake, degree of decreased lung function, nutritional status, physical activity and quality of life.

METHODS

A cross-sectional study was performed on a random sample (n = 401) at the Department of Pulmonary Rehabilitation of the National Koranyi Institute of Pulmonology from March 1, 2019 to March 1, 2020 in Budapest, Hungary. Anthropometric and respiratory function tests and laboratory parameters of all patients were registered.

RESULTS

MetS occurred in 59.1% of COPD patients with significant gender difference (male: 49.7% female: 67.6%). Concerning BMI, the prevalence of MetS was higher with BMI≥25 kg m-2 (P < 0.0001). Patients with this syndrome had significantly worse FEV1%pred (43 (30-56) vs. 47 (36-61); P = 0.028), lower quality of life (CAT: 26 (21-32) vs. 24.5 (19-29); P = 0.049) and significantly more frequent exacerbations (2 (1-3) vs.1 (0-2); P < 0.05), than patients without MetS. The prevalence of comorbidities were higher in overweight/obese patients (BMI> 25 kg m-2).

CONCLUSIONS

In COPD patients MetS negatively affect respiratory function and quality of life and promotes exacerbations of the disease. MetS is related to nutritional status and the level of systemic inflammation in COPD patients.

Lipidomic Profiling Identifies Serum Lipids Associated with Persistent Multisite Musculoskeletal Pain

Lipid mediators have been suggested to have a role in pain sensitivity and response; however, longitudinal data on lipid metabolites and persistent multisite musculoskeletal pain (MSMP) are lacking. This study was to identify lipid metabolic markers for persistent MSMP. Lipidomic profiling of 807 lipid species was performed on serum samples of 536 participants from a cohort study. MSMP was measured by a questionnaire and defined as painful sites ≥4. Persistent MSMP was defined as having MSMP at every visit. Logistic regression was used with adjustment for potential confounders. The Benjamini–Hochberg method was used to control for multiple testing. A total of 530 samples with 807 lipid metabolites passed quality control. Mean age at baseline was 61.54 ± 6.57 years and 50% were females. In total, 112 (21%) of the participants had persistent MSMP. Persistent MSMP was significantly associated with lower levels of monohexosylceramide (HexCer)(d18:1/22:0 and d18:1/24:0), acylcarnitine (AC)(26:0) and lysophosphatidylcholine (LPC)(18:1 [sn1], 18:2 [sn1], 18:2 [sn2], and 15-MHDA[sn1] [104_sn1]) after controlling for multiple testing. After adjustment for age, sex, body mass index, comorbidities, and physical activity, HexCer(d18:1/22:0 and d18:1/24:0) and LPC(15-MHDA [sn1] [104_sn1]) were significantly associated with persistent MSMP [Odds Ratio (OR) ranging from 0.25–0.36]. Two lipid classes—HexCer and LPC—were negatively associated with persistent MSMP after adjustment for covariates (OR = 0.22 and 0.27, respectively). This study identified three novel lipid signatures of persistent MSMP, suggesting that lipid metabolism is involved in the pathogenesis of persistent pain.

Dynamic Metabolic Risk Profiling of World Trade Center Lung Disease: A Longitudinal Cohort Study

Rationale: Metabolic syndrome (MetSyn) increases the risk of World Trade Center (WTC) lung injury (LI). However, the temporal relationship of MetSyn, exposure intensity, and lung dysfunction is not well understood. Objective: To model the association of longitudinal MetSyn characteristics with WTC lung disease to define modifiable risk. Methods: Firefighters, for whom consent was obtained (N = 5,738), were active duty on September 11, 2001 (9/11). WTC-LI (n = 1,475; FEV₁% predicted <lower limit of normal [LLN]) and non-WTC-LI (n = 4,263; FEV₁% predicted ⩾LLN at all exams) was the primary outcome, and FVC% predicted <LLN and FEV₁/FVC <0.70 were secondary outcomes. We assessed 1) the effect of concurrent MetSyn on longitudinal lung function by linear mixed models, 2) the temporal effect of MetSyn and exposure by Weibull proportional hazards, 3) the effects of MetSyn's rate of change by two-stage models, and 4) the nonlinear joint effect of longitudinal MetSyn components by a partially linear single-index model (PLSI). Measurements and Main Results: WTC-LI cases were more often ever-smokers, arrived in the morning (9/11), and had MetSyn. Body mass index ⩾30 kg/m² and high-density lipoprotein <40 mg/dl were most contributory to concurrent loss of FEV₁% predicted and FVC% predicted while conserving FEV₁/FVC. Body mass index ⩾30 kg/m² and dyslipidemia significantly predicted WTC-LI, FVC% predicted <LLN in a Weibull proportional hazards model. Dynamic risk assessment of WTC-LI on the basis of MetSyn and exposure showed how reduction of MetSyn factors further reduces WTC-LI likelihood in susceptible populations. PLSI demonstrates that MetSyn has a nonlinear relationship with WTC lung disease, and increases in cumulative MetSyn risk factors exponentially increase WTC-LI risk. An interactive metabolic-risk modeling application was developed to simplify PLSI interpretation. Conclusions: MetSyn and WTC exposure contribute to the development of lung disease. Dynamic risk assessment may be used to encourage treatment of MetSyn in susceptible populations. Future studies will focus on dietary intervention as a disease modifier.

Betel Nut Chewing Was Associated with Obstructive Lung Disease in a Large Taiwanese Population Study

The prevalence of betel nut chewing in Taiwan is high at approximately 7%, however, few studies have evaluated the relationship between betel nut chewing and lung disease. Therefore, the aim of this study was to investigate associations between betel nut chewing and lung function in 80,877 participants in the Taiwan Biobank (TWB). We further investigated correlations between betel nut chewing characteristics such as years of use, frequency, daily amount, and accumulative dose, with obstructive lung disease. We used data from the TWB. Lung function was assessed using spirometry measurements of forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1). The participants were classified into normal lung function and obstructive lung function (FEV1/FVC < 70%) groups. The participants were asked questions about betel nut chewing, including years of use, frequency, and daily amount. After multivariable analysis, betel nut chewing (odds ratio [OR] = 1.159; p < 0.001) was significantly associated with FEV1/FVC < 70% in all participants (n = 80,877). Further, in the participants who chewed betel nut (n = 5135), a long duration of betel nut chewing (per 1 year; OR = 1.008; p = 0.012), betel nut use every day (vs. 1–3 days/month; OR = 1.793; p = 0.036), 10–20 quids a day (vs. <10 quids; OR = 1.404; p = 0.019), 21–30 quids a day (vs. <10 quids; OR = 1.662; p = 0.010), ≥31 quids a day (vs. <10 quids; OR = 1.717; p = 0.003), and high cumulative dose (per 1 year × frequency × daily score; OR = 1.001; p = 0.002) were significantly associated with FEV1/FVC < 70%. In this large population-based cohort study, chewing betel nut was associated with obstructive lung disease. Furthermore, a long duration of betel nut chewing, more frequent use, higher daily amount, and high cumulative dose were associated with obstructive lung disease. This suggests that preventing betel nut chewing should be considered to reduce obstructive lung disease in Taiwan.

Cholesterol-Ester Transfer Protein Alters M1 and M2 Macrophage Polarization and Worsens Experimental Elastase-Induced Pulmonary Emphysema

Cholesterol-ester transfer protein (CETP) plays a role in atherosclerosis, the inflammatory response to endotoxemia and in experimental and human sepsis. Functional alterations in lipoprotein (LP) metabolism and immune cell populations, including macrophages, occur during sepsis and may be related to comorbidities such as chronic obstructive pulmonary disease (COPD). Macrophages are significantly associated with pulmonary emphysema, and depending on the microenvironment, might exhibit an M1 or M2 phenotype. Macrophages derived from the peritoneum and bone marrow reveal CETP that contributes to its plasma concentration. Here, we evaluated the role of CETP in macrophage polarization and elastase-induced pulmonary emphysema (ELA) in human CETP-expressing transgenic (huCETP) (line 5203, C57BL6/J background) male mice and compared it to their wild type littermates. We showed that bone marrow-derived macrophages from huCETP mice reduce polarization toward the M1 phenotype, but with increased IL-10. Compared to WT, huCETP mice exposed to elastase showed worsened lung function with an increased mean linear intercept (Lm), reflecting airspace enlargement resulting from parenchymal destruction with increased expression of arginase-1 and IL-10, which are M2 markers. The cytokine profile revealed increased IL-6 in plasma and TNF, and IL-10 in bronchoalveolar lavage (BAL), corroborating with the lung immunohistochemistry in the huCETP-ELA group compared to WT-ELA. Elastase treatment in the huCETP group increased VLDL-C and reduced HDL-C. Elastase-induced pulmonary emphysema in huCETP mice promotes lung M2-like phenotype with a deleterious effect in experimental COPD, corroborating the in vitro result in which CETP promoted M2 macrophage polarization. Our results suggest that CETP is associated with inflammatory response and influences the role of macrophages in COPD.

Genetic correlation and causal relationships between cardio-metabolic traits and lung function impairment

BACKGROUND

Associations of low lung function with features of poor cardio-metabolic health have been reported. It is, however, unclear whether these co-morbidities reflect causal associations, shared genetic heritability or are confounded by environmental factors.

METHODS

We performed three analyses: (1) cardio-metabolic health to lung function association tests in Northern Finland Birth cohort 1966, (2) cross-trait linkage disequilibrium score regression (LDSC) to compare genetic backgrounds and (3) Mendelian randomisation (MR) analysis to assess the causal effect of cardio-metabolic traits and disease on lung function, and vice versa (bidirectional MR). Genetic associations were obtained from the UK Biobank data or published large-scale genome-wide association studies (N > 82,000).

RESULTS

We observed a negative genetic correlation between lung function and cardio-metabolic traits and diseases. In Mendelian Randomisation analysis (MR), we found associations between type 2 diabetes (T2D) instruments and forced vital capacity (FVC) as well as FEV1/FVC. Body mass index (BMI) instruments were associated to all lung function traits and C-reactive protein (CRP) instruments to FVC. These genetic associations provide evidence for a causal effect of cardio-metabolic traits on lung function. Multivariable MR suggested independence of these causal effects from other tested cardio-metabolic traits and diseases. Analysis of lung function specific SNPs revealed a potential causal effect of FEV1/FVC on blood pressure.

CONCLUSIONS

The present study overcomes many limitations of observational studies by using Mendelian Randomisation. We provide evidence for an independent causal effect of T2D, CRP and BMI on lung function with some of the T2D effect on lung function being attributed to inflammatory mechanisms. Furthermore, this analysis suggests a potential causal effect of FEV1/FVC on blood pressure. Our detailed analysis of the interplay between cardio-metabolic traits and impaired lung function provides the opportunity to improve the quality of existing intervention strategies.

Participation of ABCA1 Transporter in Pathogenesis of Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is the important medical and social problem. According to modern concepts, COPD is a chronic inflammatory disease, macrophages play a key role in its pathogenesis. Macrophages are heterogeneous in their functions, which is largely determined by their immunometabolic profile, as well as the features of lipid homeostasis, in which the ATP binding cassette transporter A1 (ABCA1) plays an essential role. The objective of this work is the analysis of the ABCA1 protein participation and the function of reverse cholesterol transport in the pathogenesis of COPD. The expression of the ABCA1 gene in lung tissues takes the second place after the liver, which indicates the important role of the carrier in lung function. The participation of the transporter in the development of COPD consists in provision of lipid metabolism, regulation of inflammation, phagocytosis, and apoptosis. Violation of the processes in which ABCA1 is involved may be a part of the pathophysiological mechanisms, leading to the formation of a heterogeneous clinical course of the disease.

E-cig vapor condensate alters proteome and lipid profiles of membrane rafts: impact on inflammatory responses in A549 cells

Electronic cigarettes (e-cigs) are battery-operated heating devices that aerosolize e-liquid, typically containing nicotine and several other chemicals, which is then inhaled by a user. Over the past decade, e-cigs have gained immense popularity among both smokers and non-smokers. One reason for this is that they are advertised as a safe alternative to conventional cigarettes. However, the recent reports of e-cig use associated lung injury have ignited a considerable debate about the relative harm and benefits of e-cigs. The number of reports about e-cig-induced inflammation and pulmonary health is increasing as researchers seek to better understand the effects of vaping on human health. In line with this, we investigated the molecular events responsible for the e-cig vapor condensate (ECVC)-mediated inflammation in human lung adenocarcinoma type II epithelial cells (A549). In an attempt to limit the variables caused by longer ingredient lists of flavored e-cigs, tobacco-flavored ECVC (TF-ECVC±nicotine) was employed for this study. Interestingly, we observed significant upregulation of cytokines and chemokines (IL-6, IL-8, and MCP-1) in A549 cells following a 48 h TF-ECVC challenge. Furthermore, there was a significant increase in the expression of pattern recognition receptors TLR-4 and NOD-1, lipid raft-associated protein caveolin-1, and transcription factor NF-кB in TF-ECVC with and/or without nicotine-challenged lung epithelial cells. Our results further demonstrate the harboring of TLR-4 and NOD-1 in the caveolae of TF-ECVC-challenged A549 cells. Proteomic and lipidomic analyses of lipid raft fractions from control and challenged cells revealed a distinct protein and lipid profile in TF-ECVC (w/wo nicotine)-exposed A549 cells. Interestingly, the inflammatory effects of TF-ECVC (w/wo nicotine) were inhibited following the caveolin-1 knockdown, thus demonstrating a critical role of caveolae raft-mediated signaling in eliciting inflammatory responses upon TF-ECVC challenge. Graphical Abstract Graphical Abstract.

Lipid profile and atherogenic indices in patients with stable chronic obstructive pulmonary disease

BACKGROUND AND AIMS

Limited number of studies investigated lipid profile in chronic obstructive pulmonary disease (COPD) with inconsistent results. This study aimed to investigate lipid parameters in sera of patients with stable COPD and their associations with disease severity, smoking, comorbidities and therapy.

METHODS AND RESULTS

The study included 137 COPD patients and 95 controls. Triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) were assessed. Non-HDL-C (NHC), atherogenic coefficient (AC), TG/HDL-C, atherogenic index of plasma (AIP), Castelli's risk index I and II (CRI-I, CRI-II), and monocyte to HDL ratio (MHR) were calculated. HDL-C and MHR were increased, while other lipid parameters and indices were decreased in COPD patients compared to healthy individuals. Smoking did not influence lipid parameters. However, lipid profile was altered only in more severe disease stages. AC, CRI-I and CRI-II showed positive association with lung function parameters in COPD patients, and negative with COPD multicomponent indices (ADO, BODCAT, BODEx, CODEx and DOSE). Combined model that included CRI-II, C-reactive protein, fibrinogen and white blood cells showed great diagnostic performances, and correctly classified 72% of study participants with an AUC of 0.800 (0.742-0.849), P < 0.001. Bronchodilator monotherapy and statins have opposite impact on TC, LDL-C and NHC, while TG, TG/HDL-C and AIP were increased in COPD patients with cardiovascular diseases.

CONCLUSION

Lipid disbalance is present in COPD, and it seems to occur later as the disease progresses. Further studies are needed to illuminate the underlying mechanism of dyslipidaemia.

Regulation of ATP binding cassette transporter A1 (ABCA1) expression: cholesterol-dependent and - independent signaling pathways with relevance to inflammatory lung disease

The role of the ATP binding cassette transporter A1 (ABCA1) in maintaining cellular lipid homeostasis in cardiovascular disease is well established. More recently, the important beneficial role played by ABCA1 in modulating pathogenic disease mechanisms, such as inflammation, in a broad range of chronic conditions has been realised. These studies position ABCA1 as a potential therapeutic target in a diverse range of diseases where inflammation is an underlying cause. Chronic respiratory conditions such as asthma and chronic obstructive pulmonary disease (COPD) are driven by inflammation, and as such, there is now a growing recognition that we need a greater understanding of the signaling pathways responsible for regulation of ABCA1 expression in this clinical context. While the signaling pathways responsible for cholesterol-mediated ABCA1 expression have been clearly delineated through decades of studies in the atherosclerosis field, and thus far appear to be translatable to the respiratory field, less is known about the cholesterol-independent signaling pathways that can modulate ABCA1 expression in inflammatory lung disease. This review will identify the various signaling pathways and ligands that are associated with the regulation of ABCA1 expression and may be exploited in future as therapeutic targets in the setting of chronic inflammatory lung diseases.

Metabolic profiles among COPD and controls in the CanCOLD population-based cohort

A high prevalence of intermediate cardiometabolic risk factors and obesity in chronic obstructive pulmonary disease (COPD) has suggested the existence of pathophysiological links between hypertriglyceridemia, insulin resistance, visceral adiposity, and hypoxia or impaired pulmonary function. However, whether COPD contributes independently to the development of these cardiometabolic risk factors remains unclear. Our objective was to compare ectopic fat and metabolic profiles among representative individuals with COPD and control subjects and to evaluate whether the presence of COPD alters the metabolic risk profile. Study participants were randomly selected from the general population and prospectively classified as non-COPD controls and COPD, according to the Global Initiative for Chronic Obstructive Lung Disease classification. The metabolic phenotype, which consisted of visceral adipose tissue area, metabolic markers including homeostasis model assessment of insulin resistance (HOMA-IR), and blood lipid profile, was obtained in 144 subjects with COPD and 119 non-COPD controls. The metabolic phenotype was similar in COPD and controls. The odds ratios for having pathologic values for HOMA-IR, lipids and visceral adipose tissue area were similar in individuals with COPD and control subjects in multivariate analyses that took into account age, sex, body mass index, tobacco status and current medications. In a population-based cohort, no difference was found in the metabolic phenotype, including visceral adipose tissue accumulation, between COPD and controls. Discrepancies between the present and previous studies as to whether or not COPD is a risk factor for metabolic abnormalities could be related to differences in COPD phenotype or disease severity of the study populations.