The Effects of High-Fat Diet and Flaxseed Oil-Enriched Diet on the Lung Parenchyma of Obese Mice

Omega-3 (ω3) fatty acids are widely investigated for their anti-inflammatory potential, however, there is little evidence regarding their action in the lung parenchyma in the context of obesity. The objective is to investigate the effects of flaxseed oil (FS), rich in α-linolenic (C18:3 - ω3), on the lungs of obese mice. Mice were fed a high-fat diet (HF) for 8 weeks to induce obesity. Subsequently, a part of these animals received HF containing FS oil for another 8 weeks. The HF consumption induced weight gain and hyperglycemia. The lung parenchyma shows a complete fatty acids profile, compared to the control group (CT). In the lung parenchyma, FS increases the ω3 content and, notwithstanding a reduction in the interleukins (IL) IL1β and IL18 contents compared to HF. However, FS promoted increased alveolar spaces, followed by MCP1 (Monocytes Chemoattractant Protein-1) positive cell infiltration and a dramatic reduction in the anti-inflammatory cytokine, IL10. Despite reducing the pulmonary inflammatory response, the consumption of a food source of ω3 was associated with alterations in the lipid profile and histoarchitecture of the lung parenchyma, which can lead to the development of pulmonary complications. This study brings an alert against the indiscriminate use of ω3 supplements, warranting caution.

Investigating Associations of Omega-3 Fatty Acids, Lung Function Decline, and Airway Obstruction

Rationale: Inflammation contributes to lung function decline and the development of chronic obstructive pulmonary disease. Omega-3 fatty acids have antiinflammatory properties and may benefit lung health. Objectives: To investigate associations of omega-3 fatty acids with lung function decline and incident airway obstruction in a diverse sample of adults from general-population cohorts. Methods: Complementary study designs: 1) longitudinal study of plasma phospholipid omega-3 fatty acids and repeated FEV1 and FVC measures in the NHLBI Pooled Cohorts Study and 2) two-sample Mendelian randomization (MR) study of genetically predicted omega-3 fatty acids and lung function parameters. Measurements and Main Results: The longitudinal study found that higher omega-3 fatty acid levels were associated with attenuated lung function decline in 15,063 participants, with the largest effect sizes for the most metabolically downstream omega-3 fatty acid, docosahexaenoic acid (DHA). An increase in DHA of 1% of total fatty acids was associated with attenuations of 1.4 ml/yr for FEV1 (95% confidence interval [CI], 1.1-1.8) and 2.0 ml/yr for FVC (95% CI, 1.6-2.4) and a 7% lower incidence of spirometry-defined airway obstruction (95% CI, 0.89-0.97). DHA associations persisted across sexes and smoking histories and in Black, White, and Hispanic participants, with associations of the largest magnitude in former smokers and Hispanic participants. The MR study showed similar trends toward positive associations of genetically predicted downstream omega-3 fatty acids with FEV1 and FVC. Conclusions: The longitudinal and MR studies provide evidence supporting beneficial effects of higher levels of downstream omega-3 fatty acids, especially DHA, on lung health.

Investigating associations of omega-3 fatty acids, lung function decline, and airway obstruction

Rationale

Inflammation contributes to lung function decline and the development of chronic obstructive pulmonary disease. Omega-3 fatty acids have anti-inflammatory properties and may benefit lung health.

Objectives

Investigate associations of omega-3 fatty acids with lung function decline and incident airway obstruction in adults of diverse races/ethnicities from general population cohorts.

Methods

Complementary study designs: (1) longitudinal study of plasma phospholipid omega-3 fatty acids and repeated FEV 1 and FVC measures in the National Heart, Lung, and Blood Institute Pooled Cohorts Study, and (2) two-sample Mendelian Randomization (MR) study of genetically predicted omega-3 fatty acids and lung function parameters.

Measurements and Main Results

The longitudinal study found that higher omega-3 fatty acid concentrations were associated with attenuated lung function decline in 15,063 participants, with the largest effect sizes for docosahexaenoic acid (DHA). One standard deviation higher DHA was associated with an attenuation of 1.8 mL/year for FEV 1 (95% confidence interval [CI] 1.3-2.2) and 2.4 mL/year for FVC (95% CI 1.9-3.0). One standard deviation higher DHA was also associated with a 9% lower incidence of spirometry-defined airway obstruction (95% CI 0.86-0.97). DHA associations persisted across sexes, smoking histories, and Black, white and Hispanic participants, with the largest magnitude associations in former smokers and Hispanics. The MR study showed positive associations of genetically predicted omega-3 fatty acids with FEV 1 and FVC, with statistically significant findings across multiple MR methods.

Conclusions

The longitudinal and MR studies provide evidence supporting beneficial effects of higher circulating omega-3 fatty acids, especially DHA, on lung health.

An immune-shift induced by lycopene; from an eosinophil-dominant type towards an eosinophil/neutrophil-co-dominant type of airway inflammation

Lycopene as the main carotenoid from tomatoes is known to have beneficial effects on various inflammatory diseases. In mice, lycopene ameliorates asthma symptoms and in human asthmatic patients serum lycopene levels are reduced. To further investigate the immunomodulatory effect of lycopene, first, we used a ragweed pollen extract (RWE)-induced asthma model in mice. In a second approach, we established a RWE-induced asthma model in gerbils, because of a more human-like carotenoid absorption in these animals. In RWE-sensitized/RWE-challenged gerbils (C+) following a basal diet, mainly the number of eosinophils in the broncho-alveolar lavage (BAL) significantly increased, comparable to RWE-sensitized/PBS-challenged gerbils (C-). In RWE-sensitized/PBS-challenged gerbils with lycopene-supplementation (L-), an elevated number of mainly neutrophils, in addition to eosinophils, was detected compared to C-, whereas in RWE-sensitized/RWE-challenged animals with lycopene-supplementation (L+), mainly increased neutrophil numbers in BAL were detected compared to C+. Furthermore, using LC-MS, we determined an array of eicosanoids/docosanoids in the lungs and observed that 5-, 8-lipoxygenase (LOX) and cyclooxygenase (COX) pathways were significantly increased after intranasal RWE-challenge in sensitized mice and just by tendency in gerbils. In PBS- and RWE-challenged animals, lycopene-supplementation significantly raised COX-pathway metabolites. In conclusion, we found that lycopene-supplementation resulted in an increased inflammatory influx of neutrophils in combination with increased COX-pathways metabolites. This pro-inflammatory, pro-neutrophil activity induced by lycopene might be an important shift from allergic asthma towards an inflammatory symptomatic asthma type, though with the potential for resolution.

Polymorphisms rs2745557 in PTGS2 and rs2075797 in PTGER2 are associated with the risk of chronic obstructive pulmonary disease development in a Tunisian cohort

We hypothesized that polymorphisms of genes involved in the prostaglandin pathway could be associated with COPD. In this study we explored the involvement of genetic polymorphisms in PTGS2, PTGER2 and PTGER4 genes in the development and severity of COPD and their effects on plasma concentrations of inflammatory/oxidative stress markers. We identified genotypes of PTGS2, PTGER2 and PTGER4 SNPs in a Tunisian cohort including COPD patients (n = 138) and control subjects (n = 216) using PCR-RFLP and PCR TaqMan. Pulmonary function (FEV1 and FVC) were assessed by plethsmography. PGE₂, PGD₂ and cytokine plasma (IL-6, IL-18, TNF-α, TGF-β) concentrations were measured using ELISA and colorimetric standard methods were used to determine oxidative stress concentrations. Genotype frequencies of rs2745557 in PTGS2 and rs2075797 in PTGER2 were different between COPD cases and controls. There was no correlation between these polymorphisms and lung function parameters. For rs2745557, the A allele frequency was higher in COPD cases than in controls. For rs2075797, carriers of the GG genotype were more frequent in the COPD group than in controls. Only rs2745557 in PTGS2 had an effect on PGD₂ and cytokine plasma concentrations. PGD₂ was significantly decreased in COPD patients with the GA or AA genotypes. In contrast, IL-18 and NO plasma concentrations were increased in COPD rs2745557 A allele carriers as compared to homozygous GG subjects. Our findings suggest that rs2745557 in PTGS2 and rs2075797 in PTGER2 are associated with COPD development but not with its severity.

Lipid-Embedded Molecular Dynamics Simulation Model for Exploring the Reverse Prostaglandin D2 Agonism of CT-133 towards CRTH2 in the Treatment of Type-2 Inflammation Dependent Diseases

Chemoattractant receptor-homologous molecule expressed on Th2 cells (CRTH2) has been involved in several inflammation dependent diseases by mediating the chemotaxis of pro-inflammatory cells in response to allergy and other responses through PGD2 ligation. This CRTH2-PGD2 signaling pathway has become a target for treating allergic and type 2 inflammation dependent diseases, with many inhibitors developed to target the PGD2 binding pocket. One of such inhibitors is the ramatroban analog, CT-133, which exhibited therapeutic potency cigarette smoke-induced acute lung injury in patients. Nonetheless, the molecular mechanism and structural dynamics that accounts for its therapeutic prowess remain unclear. Employing computational tools, this study revealed that although the carboxylate moiety in CT-133 and the native agonist PGD2 aided in their stability within the CRTH2 binding pocket, the tetrahydrocarbazole group of CT-133 engaged in strong interactions with binding pocket residues which could have formed as the basis of the antagonistic advantage of CT-133. Tetrahydrocarbazole group interactions also enhanced the relative stability CT-133 within the binding pocket which consequently favored CT-133 binding affinity. CT-133 binding also induced an inactive or 'desensitized' state in the helix 8 of CRTH2 which could conversely favor the recruitment of arrestin. These revelations would aid in the speedy development of small molecule inhibitors of CRTH2 in the treatment of type 2 inflammation dependent diseases.

The relationship between inflammatory markers and spirometric parameters in ACOS, Asthma, and COPD

Objective: The inflammatory mechanisms underpinning asthma-chronic obstructive pulmonary disease (COPD) overlap syndrome (ACOS) have not been fully elucidated. Here, we examined the levels of cysteinyl leukotrienes (cys-LTs), prostaglandin D2 (PG-D2), prostaglandin E2 (PG-E2), interleukin 5 (IL-5), and a disintegrin and metalloprotease domain (ADAM 33) in ACOS patients to determine the relationship between levels of these inflammatory markers and pulmonary functions.Methods: Blood samples were obtained from asthma, COPD, and ACOS patients who received combined therapy and were stable for the last month to measure cys-LTs, PG-D2, PG-E2, IL-5, and ADAM33 levels. Differences between groups and their correlations with pulmonary function tests were evaluated.Results: In total, 24 ACOS, 27 asthma, and 35 COPD patients were included. . PG-D2 levels were higher in ACOS (120.9 ± 117.2 ng/L) and asthma (119.6 ± 111.7 ng/L) patients than in COPD (82.6 ± 46.7 ng/L) patients (p = 0.036 and p = 0.038, respectively). In ACOS patients, PG-D2, cys-LTs, and ADAM33 levels were negatively correlated with FEV1/FVC% values (p = 0.021, p = 0.008, and p = 0.028, respectively). In COPD patients, a negative correlation was detected between PG-E2 and FEV1/FVC% (p = 0.007), whereas positive correlations were detected between IL-5 and pulmonary function tests, including FVC, FVC%, FEV1, FEV1%, FEF25-75, and FEF25-75% (p = 0.047, p = 0.005, p = 0.002, p = 0.002, p = 0.010, and p = 0.005, respectively). In asthma patients, cys-LTs levels were negatively correlated with FEV1 and FEF25-75 values (p = 0.045 and p = 0.037, respectively).Conclusions: PG-D2 levels may be a valuable biomarker to differentiate COPD in asthma and ACOS patients.

CRTH2 antagonist, CT‑133, effectively alleviates cigarette smoke-induced acute lung injury

AIMS

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS), characterized by overwhelming lung inflammation, are associated with high mortality. Cigarette smoke (CS) is one of the major causes of ALI/ARDS. Since high expression of prostaglandin (PG) D2 has been observed in CS-induced lung injury. Currently, no effective pharmacological therapies are available to treat ALI, and supportive therapies remain the mainstay of treatment. Therefore, we investigated the protective effect of CT‑133, a newly discovered selective CRTH2 antagonist, on CS-induced ALI in vivo and in vitro.

MAIN METHODS

CT‑133 (10 and 30 mg/kg), dexamethasone (1 mg/kg) and normal saline were intratracheally administrated 1 hr prior to whole-body CS-exposure for seven consecutive days to study the key characteristics of ALI. Subsequently, CSE (4%)- and PGD2-stimulated RAW 264.7 macrophages were used to evaluate the protective effect of CT‑133.

KEY FINDINGS

CT‑133 remarkably attenuated infiltration of inflammatory cells, neutrophils, and macrophages in the BALF, albumin contents, expression of IL‑1β, IL‑6, TNF‑α and KC, lung myeloperoxidase (MPO) activity and lung histopathological alterations caused by CS exposure in mice. Moreover, CT‑133 not only reversed the uncontrolled secretion of IL‑1β, IL-6, TNF‑α and KC from CSE- and PGD2-stimulated RAW 264.7 macrophages but also augmented IL-10 production in both in vivo and in vitro studies. Additionally, CT‑133 alleviated in vitro neutrophil migration chemoattracted by PGD2.

SIGNIFICANCE

Our results provide the first evidence that targeting CRTH2 could be a new potential therapeutic option to treat CS-induced ALI.

Dietary intake of fatty acids and its relationship with FEV1/FVC in patients with chronic obstructive pulmonary disease

BACKGROUND & AIMS

The deterioration of pulmonary function has been associated with increased levels of systemic inflammation that can be stimulated by consumption of saturated fatty acids and trans fats. We hypothesized that fatty acids intake impact on pulmonary function. However, evidence about the impact of different types of fatty acids on pulmonary function in patients with chronic obstructive pulmonary disease (COPD) is limited and heterogeneous. The aim of this study was to evaluate the association between intake of fatty acids and pulmonary function in patients with COPD.

METHODS

Cross sectional study of patients diagnosed with COPD. The relationship between consumption of fatty acids and the FEV₁/FVC ratio obtained by spirometry was assessed. Patients with exacerbations during the prior 2 months, diagnosis of asthma or administration of a dietary supplement were excluded.

RESULTS

A simple linear regression showed that for each gram of carbohydrates and total l fatty acids intake, the FEV₁/FVC ratio decreased -0.03 ml (β: -0.03, 95% CI -0.06 to -0.01, p = 0.008) and -0.009 ml (β: -0.00, 95% CI -0.02 to 0.00, p = 0.031) respectively. Pentadecanoic acid (C15:0) was associated with an increase of 0.47 ml in the FEV₁/FVC ratio for each milligram intake (β: 0.47, 95% CI 0.04 to 0.91, p = 0.031). Subsequently, when adjusted for calories intake, an increase of 0.53 ml was observed in the FEV₁/FVC for each milligram of C15:0 fatty acid intake (β:0.53, 95% CI 0.09 to 0.97, p = 0.018).

CONCLUSION

A positive association was observed between pentadecanoic acid and the FEV₁/FVC ratio with a beneficial effect on patients with COPD.

Serum Metabolite Biomarkers Discriminate Healthy Smokers from COPD Smokers

COPD (chronic obstructive pulmonary disease) is defined by a fixed expiratory airflow obstruction associated with disordered airways and alveolar destruction. COPD is caused by cigarette smoking and is the third greatest cause of mortality in the US. Forced expiratory volume in 1 second (FEV1) is the only validated clinical marker of COPD, but it correlates poorly with clinical features and is not sensitive enough to predict the early onset of disease. Using LC/MS global untargeted metabolite profiling of serum samples from a well-defined cohort of healthy smokers (n = 37), COPD smokers (n = 41) and non-smokers (n = 37), we sought to discover serum metabolic markers with known and/or unknown molecular identities that are associated with early-onset COPD. A total of 1,181 distinct molecular ions were detected in 95% of sera from all study subjects and 23 were found to be differentially-expressed in COPD-smokers vs. healthy-smokers. These 23 putative biomarkers were differentially-correlated with lung function parameters and used to generate a COPD prediction model possessing 87.8% sensitivity and 86.5% specificity. In an independent validation set, this model correctly predicted COPD in 8/10 individuals. These serum biomarkers included myoinositol, glycerophopshoinositol, fumarate, cysteinesulfonic acid, a modified version of fibrinogen peptide B (mFBP), and three doubly-charged peptides with undefined sequence that significantly and positively correlate with mFBP levels. Together, elevated levels of serum mFBP and additional disease-associated biomarkers point to a role for chronic inflammation, thrombosis, and oxidative stress in remodeling of the COPD airways. Serum metabolite biomarkers offer a promising and accessible window for recognition of early-stage COPD.

Paucity of evidence for a relationship between long-chain omega-3 fatty acid intake and chronic obstructive pulmonary disease: a systematic review

CONTEXT

The anti-inflammatory activity of long-chain n-3 polyunsaturated fatty acids (PUFAs) has been established in several chronic inflammatory diseases but has yet to be demonstrated in inflammatory lung diseases such as chronic obstructive pulmonary disease (COPD).

OBJECTIVE

The aim of this systematic review was to investigate, using PRISMA guidelines, the relationship between the intake of long-chain n-3 PUFAs and the prevalence, severity, and health outcomes of COPD.

DATA SOURCES

Eight health databases and the World Health Organization's international clinical trial registry were searched for relevant studies.

STUDY SELECTION

Experimental or observational studies that were published in English and that assessed long-chain n-3 PUFA intake (by determining habitual consumption and/or tissue levels) in adults with COPD were included.

DATA EXTRACTION

Publication demographics, participant characteristics, type of intervention or exposure, long-chain n-3 PUFA intake, pulmonary function, COPD mortality, and COPD severity were independently extracted from each article by 2 authors using a prospectively designed data extraction tool.

DATA SYNTHESIS

All 11 of the studies included in the review were observational. Approximately equal numbers of studies reported significant (n = 6, 5 inverse) relationships or no significant relationships (n = 5) between either consumption of long-chain n-3 PUFAs or levels of long-chain n-3 PUFAS in tissue and a COPD outcome.

CONCLUSIONS

Current evidence of a relationship between long-chain n-3 PUFA intake and COPD is limited and conflicting, with studies having wide methodological variation.

REGISTRATION NUMBER

PROSPERO 2013:CRD42013004085.

Omega-3 polyunsaturated fatty acids and chronic obstructive pulmonary disease

PURPOSE OF REVIEW

The aim of the present review was to summarize recent research developments relating omega-3 polyunsaturated fatty acids (PUFAs) and chronic obstructive pulmonary disease (COPD).

RECENT FINDINGS

COPD is a chronic inflammatory disease; hence, omega-3 PUFAs may have beneficial effects. At present, however, there are limited data available regarding the potential for omega-3 PUFAs to be used therapeutically in COPD. In 2012-2013, several observational studies have emerged, which demonstrate that circulating omega-3 PUFA levels in COPD are inversely associated with systemic inflammation and positively associated with clinical outcomes. To date, all interventions incorporating omega-3 PUFAs in COPD have used nutrient combinations, such that the specific effects of omega-3 PUFAs cannot be determined. Three clinical trials in COPD are underway, which use therapeutic doses of omega-3 PUFAs alone, with positive results beginning to emerge in 2014.

SUMMARY

Observational data support the hypothesis that omega-3 PUFAs may provide a therapeutic strategy for managing COPD. Several intervention trials using omega-3 PUFAs in COPD are underway, which will provide a substantive amount of new data to inform the field and allow evidence-based advice to be generated for patients with COPD in the near future.

Bioanalytical insights into mediator lipidomics

The importance of lipids in health and disease has been widely acknowledged. Lipids are well known to undergo enzymatic and/or non-enzymatic conversions to lipid mediators (LMs), which demonstrate potent actions in various biological events, such as the regulation of cellular signaling pathways and the promotion and resolution of inflammation. LMs activate G-protein-coupled receptors (GPCRs) to exert various functions. Monitoring these mediators in disease is essential to uncover the mechanisms of pathogenesis for many diseases, such as asthma, rheumatoid arthritis, Alzheimer's disease, and cancer. Along with technical developments in mass spectrometry, highly sensitive and multiplexed analyses of LMs in the human periphery and other tissues have become available. These advancements enable the temporal and spatial profiling of LMs; therefore, the findings obtained from LM profiling are expected to decode pathology. As trace amounts of LMs can exert functions, the development of a highly sensitive, accurate, and robust analytical method is necessary. Although not mandatory, mediator lipidomics validation is becoming popular and remains challenging. Because LMs already exist in biological matrices, evaluations of the matrix effect and extraction efficiencies are important issues. Thus, more careful analyses are required. In this review, we focus on mediator lipidomics, including polyunsaturated fatty acids (PUFAs), such as omega-3 and omega-6 fatty acids, and LMs derived from PUFAs, such as eicosanoids, lipoxins and resolvins. In addition to the recent progress in human mediator lipidomics, bioanalytical insights derived from this field (i.e., effective sample preparation from biological matrices and evaluation of the matrix effect) are described herein.

Prostaglandin D2 inhibits collagen secretion from lung fibroblasts by activating the DP receptor

Lung fibroblasts are responsible for collagen secretion during normal tissue repair and the development of fibrosis. Many other prostaglandins have been reported to regulate collagen synthesis in lung fibroblasts, but the role of prostaglandin D2 (PGD2) is unknown. In this study, we investigated the effect of PGD2 on type I collagen secretion in human lung fibroblasts. Pretreatment with PGD2 (0.1 - 10 μM, 1 h) significantly attenuated type I collagen secretion to the cell supernatant induced by transforming growth factor-β (TGF-β). Although an agonist on chemoattractant receptorhomologous molecule expressed on Th2 cells (CRTH2) did not have any effect, the prostanoid DP-receptor agonist BW245C (0.01 - 1 μM) suppressed TGF-β-induced collagen secretion. PGD2 and BW245C significantly increased intracellular cAMP level. One-hour pretreatment with forskolin (0.1 - 10 μM), dibutyryl-cAMP (0.01 - 1 mM), and the protein kinase A (PKA)-activator N(6)-phenyl-cyclic AMP (100 μM) significantly reduced TGF-β-induced collagen secretion, while exchange protein activated by cAMP (Epac) activator 8-bromo-2'-O-methyladenosine-3',5'-cyclic AMP (10 μM) did not affect collagen deposition. These results suggest that PGD2 inhibits TGF-β-induced collagen secretion via intracellular cAMP accumulation through activating DP receptor.

Functional polymorphism of cyclooxygenase-2 gene (G-765C) in chronic obstructive pulmonary disease patients

Cyclooxygenase two (COX-2) is an important enzyme metabolizing arachidonic acid. In contrast to constitutive cyclooxygenase one (COX-1), COX-2 is induced by proinflammatory factors. Polymorphism -765 G/C in COX-2-encoding gene promoter is associated with development of Alzheimer's disease, depression, carcinoma of the pancreas in smokers, breast cancer and rheumatoid arthritis. It is interesting whether the -765 G/C polymorphism in COX-2-encoding gene promoter can be associated with COPD, a disease which is inflammatory in character. It is highly probable as the breast and pancreas cancers, whose associations with the analyzed polymorphism have been studied, are smoking-dependent tumors. Additionally, tobacco smoke has been demonstrated to induce COX-2 in the lungs. The study group consisted of 122 COPD patients (48 females, 74 males). The control group consisted of 149 healthy nonsmoking subjects (83 females, 66 males). Polymerase chain reaction/restriction fragment length polymorphism was used for genotyping. A statistically significant difference in genotype distribution was observed as a result of the comparison between healthy subjects and patients with COPD. The distribution of alleles in both groups conformed with Hardy-Weinberg equilibrium. In the group of COPD patients, GG allele was found in 79 subjects, GC in 36, and CC in 7 subjects (F = 0.094, P = 0.296927); in the control group, 73 subjects had GG allele, 68--GC and 8--CC (F = 0.12728, P = 0.120265). The allele frequency revealed differences between those groups, attaining the level of statistical significance (χ(2) = 29.043, df = 2, P = 0.0000. The carriers of -765 G allele are at 1.53-fold higher risk of developing COPD. The presence of GG genotype does not increase significantly the risk of the disease. It is also noteworthy that the carriers of CC or GC genotypes are at significantly lower risk of developing COPD than the group of subjects with GG genotype.

Biomarkers in COPD

Although there is increasing interest in using pulmonary biomarkers for a more complete and clinically relevant assessment of COPD and a plethora of biomarkers are becoming available, there is little information regarding their reproducibility and correlation with other outcome measurements in COPD. The lack of well-validated biomarkers that can be used for monitoring disease activity, predicting future clinical outcomes and the effect of therapeutic interventions highlights the factual need to identify new biomarkers in COPD. It is likely that, using what is called 'integrative functional informatics', which is a novel direction in the interfacing and integration of different technologies (genomics, proteomics, metabolomics and metabonomics, pharmacogenetics, and integrative approaches) for collection and analysis of data on biomarkers, we will be able to identify robust, reliable, and reproducible biomarkers in COPD.