Lower leptin/adiponectin ratio and risk of rapid lung function decline in chronic obstructive pulmonary disease

Polygenic and transcriptional risk scores identify chronic obstructive pulmonary disease subtypes

Rationale

Genetic variants and gene expression predict risk of chronic obstructive pulmonary disease (COPD), but their effect on COPD heterogeneity is unclear.

Objectives

Define high-risk COPD subtypes using both genetics (polygenic risk score, PRS) and blood gene expression (transcriptional risk score, TRS) and assess differences in clinical and molecular characteristics.

Methods

We defined high-risk groups based on PRS and TRS quantiles by maximizing differences in protein biomarkers in a COPDGene training set and identified these groups in COPDGene and ECLIPSE test sets. We tested multivariable associations of subgroups with clinical outcomes and compared protein-protein interaction networks and drug repurposing analyses between high-risk groups.

Measurements and Main Results

We examined two high-risk omics-defined groups in non-overlapping test sets (n=1,133 NHW COPDGene, n=299 African American (AA) COPDGene, n=468 ECLIPSE). We defined "High activity" (low PRS/high TRS) and "severe risk" (high PRS/high TRS) subgroups. Participants in both subgroups had lower body-mass index (BMI), lower lung function, and alterations in metabolic, growth, and immune signaling processes compared to a low-risk (low PRS, low TRS) reference subgroup. "High activity" but not "severe risk" participants had greater prospective FEV 1 decline (COPDGene: -51 mL/year; ECLIPSE: - 40 mL/year) and their proteomic profiles were enriched in gene sets perturbed by treatment with 5-lipoxygenase inhibitors and angiotensin-converting enzyme (ACE) inhibitors.

Conclusions

Concomitant use of polygenic and transcriptional risk scores identified clinical and molecular heterogeneity amongst high-risk individuals. Proteomic and drug repurposing analysis identified subtype-specific enrichment for therapies and suggest prior drug repurposing failures may be explained by patient selection.

Associations between long-term night shift work and incidence of chronic obstructive pulmonary disease: a prospective cohort study of 277,059 UK Biobank participants

BACKGROUND

Little is known about the effects of night shifts and their interactions with genetic factors on chronic obstructive pulmonary disease (COPD). In this study, we aim to investigate relationships between long-term night shift work exposure and COPD risk, and assess modification effects of genetic predisposition.

METHODS

A total of 277,059 subjects who were in paid employment or self-employed were included in the UK Biobank. Information on current and lifetime employment was obtained, and a weighted COPD-specific genetic risk score (GRS) was constructed. We used Cox proportional hazard models to investigate associations between night shift work and COPD risk, and their interaction with COPD-specific GRS.

RESULTS

The cohort study included 277,059 participants (133,063 men [48.03%]; mean [SD] age, 52.71 [7.08] years). During a median follow-up of 12.87 years, we documented 6558 incidents of COPD. From day work, irregular night shifts to regular night shifts, there was an increased trend in COPD incidence (P for trend < 0.001). Compared with day workers, the hazard ratio (HR) and 95% confidence interval (CI) of COPD was 1.28 (1.20, 1.37) for subjects with rarely/sometimes night shifts and 1.49 (1.35, 1.66) for those with permanent night shifts. Besides, the longer durations (especially in subjects with night shifts ≥ 10 years) and increasing monthly frequency of night shifts (in workers with > 8 nights/month) were associated with a higher COPD risk. Additionally, there was an additive interaction between night shifts and genetic susceptibility on the COPD risk. Subjects with permanent night shifts and high genetic risk had the highest risk of COPD (HR: 1.90 [95% CI: 1.63, 2.22]), with day workers with low genetic risk as a reference.

CONCLUSIONS

Long-term night shift exposure is associated with a higher risk of COPD. Our findings suggest that decreasing the frequency and duration of night shifts may offer a promising approach to mitigating respiratory disease incidence in night shift workers, particularly in light of individual susceptibility.

Can adipokines predict clinical prognosis and post-COVID lung sequelae?

BACKGROUND

Adipokines play an important role in the regulation of inflammatory responses toward infections, including COVID-19. This study aimed to investigate the role of chemerin, adiponectin, and leptin in prognosis and post-COVID lung sequelae in hospitalized patients with COVID-19.

METHODS

Serum levels of the three adipokines were measured upon admission of polymerase chain reaction-confirmed patients with COVID-19 who were followed up for 6 months for the clinical outcome and lung sequelae formation.

RESULTS

A total of 77 patients were included in the study. Of the 77 patients, 58.4% were males, and the median age was 63.2 ± 18.3 years. Fifty-one patients (66.2%) had a good prognosis. Among adipokines, only chemerin was significantly lower in the bad prognosis group (P < 0.05), and the serum levels showed a negative correlation with age (rho = -0.238; P < 0.05). Leptin levels were negatively correlated with gamma glutamyl transferase levels, which were significantly higher in the bad prognostic group (rho = -0.240; P < 0.05). Twenty-four patients had no lung sequelae, and 20 developed sequelae within 6 months after infection. Chemerin/adiponectin ratio with a cut-off value of 0.96 and an area under the curve 0.679 (P < 0.05) might predict the sequelae formation.

CONCLUSIONS

Chemerin levels are lower, especially in patients with a bad prognosis, and the chemerin/adiponectin ratio might predict the development of lung sequelae in patients with COVID-19.

Clinical characteristics and natural course of chronic obstructive pulmonary disease and/or asthma in Japanese patients: a summary report of two Hokkaido-based cohort studies

Chronic obstructive pulmonary disease (COPD) and asthma are the most common chronic airway diseases and are characterized by chronic airway inflammation and airflow limitation. Japanese patients with COPD or asthma have characteristics different from those of Westerners. Therefore, understanding the characteristics and clinical course of Japanese patients with COPD and those with asthma, particularly severe asthma, is critical for their management and appropriate treatment. The Hokkaido COPD cohort and Hokkaido-based Investigative Cohort Analysis for Refractory Asthma (Hi-CARAT) are high-quality cohort studies of COPD and asthma in the Japanese population and provide valuable data. This report summarizes the clinical findings from the two cohort studies and provides data for more appropriate management of Japanese patients with COPD and/or asthma. Overall, 279 patients with COPD were followed up for up to 10 years in the Hokkaido COPD cohort study, and 127 with severe asthma were followed up for up to 6 years in the Hi-CARAT study. Seventy-nine patients with mild-to-moderate asthma provided baseline data for the Hi-CARAT study. In each disease, several distinct factors, including systemic status and non-pulmonary factors, were associated with important clinical outcomes, such as lung function decline, exacerbations, impaired quality of life, and mortality. Therefore, multifaceted evaluation based on the characteristics of the Japanese population is necessary for the management of COPD and asthma.

A blood and bronchoalveolar lavage protein signature of rapid FEV1 decline in smoking-associated COPD

Accelerated progression of chronic obstructive pulmonary disease (COPD) is associated with increased risks of hospitalization and death. Prognostic insights into mechanisms and markers of progression could facilitate development of disease-modifying therapies. Although individual biomarkers exhibit some predictive value, performance is modest and their univariate nature limits network-level insights. To overcome these limitations and gain insights into early pathways associated with rapid progression, we measured 1305 peripheral blood and 48 bronchoalveolar lavage proteins in individuals with COPD [n = 45, mean initial forced expiratory volume in one second (FEV1) 75.6 ± 17.4% predicted]. We applied a data-driven analysis pipeline, which enabled identification of protein signatures that predicted individuals at-risk for accelerated lung function decline (FEV1 decline ≥ 70 mL/year) ~ 6 years later, with high accuracy. Progression signatures suggested that early dysregulation in elements of the complement cascade is associated with accelerated decline. Our results propose potential biomarkers and early aberrant signaling mechanisms driving rapid progression in COPD.

Adipose Tissue Inflammation and Pulmonary Dysfunction in Obesity

Obesity is a chronic disease caused by an excess of adipose tissue that may impair health by altering the functionality of various organs, including the lungs. Excessive deposition of fat in the abdominal area can lead to abnormal positioning of the diaphragm and consequent reduction in lung volume, leading to a heightened demand for ventilation and increased exposure to respiratory diseases, such as chronic obstructive pulmonary disease, asthma, and obstructive sleep apnoea. In addition to mechanical ventilatory constraints, excess fat and ectopic deposition in visceral depots can lead to adipose tissue dysfunction, which promotes metabolic disorders. An altered adipokine-secretion profile from dysfunctional adipose tissue in morbid obesity fosters systemic, low-grade inflammation, impairing pulmonary immune response and promoting airway hyperresponsiveness. A potential target of these adipokines could be the NLRP3 inflammasome, a critical component of the innate immune system, the harmful pro-inflammatory effect of which affects both adipose and lung tissue in obesity. In this review, we will investigate the crosstalk between adipose tissue and the lung in obesity, highlighting the main inflammatory mediators and novel therapeutic targets in preventing pulmonary dysfunction.

Unique Mortality Profile in Japanese Patients with COPD: An Analysis from the Hokkaido COPD Cohort Study

Purpose

Causes of death may be unique and different in Japanese patients with COPD because they are generally older, thinner, experience fewer exacerbations, and live longer than those in other countries. We investigated the detailed mortality profile in the Hokkaido COPD cohort study, which completed a 10-year follow-up with a very low dropout rate.

Patients and Methods

We prospectively examined the 10-year natural history in 279 Japanese patients with COPD (GOLD 1, 26%; GOLD 2, 45%; GOLD 3, 24%; and GOLD 4, 5%). The majority of patients were male, and the average age at baseline was 69 years old. About 95% of all patients had accurate mortality data. The risk factors for mortality were also analyzed.

Results

During the 10 years, 112 patients (40%) died. Their median survival time was 6.1 years (interquartile range: 4.7–7.9 years), and age at death was 79 ± 6 years old (mean ± SD). Respiratory diseases, including pneumonia, were the leading causes of death in 45 (40%), followed by lung cancer in 24 (21%), other cancers in 18 (16%), and cardiovascular diseases in 12 (11%). In particular, lung cancer-related death was equally distributed across all COPD stages, with a higher proportion of lung cancer in the relatively younger generation (<64 years old). Older age at baseline, lower BMI, and severer emphysema were significant risk factors for all-cause mortality.

Conclusion

The unique mortality profile observed in this study should be considered when designing strategies for the management of patients with COPD in any geographic region.

Chronic Obstructive Pulmonary Disease in Women: A Biologically Focused Review with a Systematic Search Strategy

Purpose

Evidence suggests that chronic obstructive pulmonary disease (COPD) symptoms and progression may differ between men and women. However, limited information is currently available on the pathophysiological and biological factors that may underlie these sex-related differences. The objective of this review is to systematically evaluate reports of potential sex-related differences, including genetic, pathophysiological, structural, and other biological factors, that may influence COPD development, manifestation, and progression in women.

Patients and Methods

A PubMed literature search was conducted from inception until January 2020. Original reports of genetic, hormonal, and physiological differences, and biological influences that could contribute to COPD development, manifestation, and progression in women were included.

Results

Overall, 491 articles were screened; 29 articles met the inclusion criteria. Results from this analysis demonstrated between-sex differences in inflammatory, immune, genetic, structural, and physiological factors in patients with COPD.

Conclusion

Various biological differences are observed between men and women with COPD including differences in inflammatory and metabolic pathways related to obesity and fat distribution, immune cell function and autophagy, extent and distribution of emphysema and airway wall remodeling. An enhanced understanding of these differences has the potential to broaden our understanding of how COPD develops and progresses, thereby providing an opportunity to ultimately improve diagnosis, treatment, and monitoring of COPD in both men and women.

Identifying Protein-metabolite Networks Associated with COPD Phenotypes

Chronic obstructive pulmonary disease (COPD) is a disease in which airflow obstruction in the lung makes it difficult for patients to breathe. Although COPD occurs predominantly in smokers, there are still deficits in our understanding of the additional risk factors in smokers. To gain a deeper understanding of the COPD molecular signatures, we used Sparse Multiple Canonical Correlation Network (SmCCNet), a recently developed tool that uses sparse multiple canonical correlation analysis, to integrate proteomic and metabolomic data from the blood of 1008 participants of the COPDGene study to identify novel protein-metabolite networks associated with lung function and emphysema. Our aim was to integrate -omic data through SmCCNet to build interpretable networks that could assist in the discovery of novel biomarkers that may have been overlooked in alternative biomarker discovery methods. We found a protein-metabolite network consisting of 13 proteins and 7 metabolites which had a -0.34 correlation (p-value = 2.5 × 10^-28) to lung function. We also found a network of 13 proteins and 10 metabolites that had a -0.27 correlation (p-value = 2.6 × 10^-17) to percent emphysema. Protein-metabolite networks can provide additional information on the progression of COPD that complements single biomarker or single -omic analyses.

Serum Alpha-1 Antitrypsin Levels and the Clinical Course of Chronic Obstructive Pulmonary Disease

Purpose

Alpha-1 antitrypsin deficiency is associated with the development of chronic obstructive pulmonary disease (COPD), whereas increased levels of serum alpha-1antitrypsin occur in response to inflammation. The effects of alpha-1 antitrypsin levels on the clinical course of COPD had been unclear. We investigated the association of serum alpha-1 antitrypsin levels with the clinical course of COPD patients based on data from a 10-year prospective cohort study.

Patients and methods

We analyzed 278 COPD patients who participated in the Hokkaido COPD cohort study and who did not meet the criteria for alpha-1 antitrypsin deficiency. We divided the subjects into 3 groups according to quartiles of serum alpha-1 antitrypsin levels at baseline: lower group (<116 mg/dL, n = 66); middle group (116 to ≤141 mg/dL, n = 145); and higher group (>141 mg/dL, n = 67). The annual change in forced expiratory volume in 1 s (FEV₁) and events of COPD exacerbation were monitored during the first 5 years, and mortality was followed-up during the entire 10 years.

Results

At baseline, the higher group showed lower body mass index; higher computed tomography emphysema score; lower diffusing capacity; higher levels of acute-phase proteins; and higher blood neutrophil counts. Longitudinal analyses revealed that in the higher group, the annual decline in FEV₁ was rapid and the 10-year mortality was higher, but there was no association between serum alpha-1 antitrypsin levels and time to first exacerbation.

Conclusion

COPD subjects with higher serum alpha-1 antitrypsin levels were associated with a worse systemic inflammation status and higher 10-year mortality.

An immunometabolic pathomechanism for chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is an inflammatory disease characterized by limitation of expiratory airflow. Cellular and molecular pathways involved in disease pathogenesis are not completely defined. Our study reveals that metabolism and immune response cooperate in COPD pathogenesis and progression. COPD subjects with different disease stages showed progressive increase of systemic leptin, an adipose tissue-derived proinflammatory molecule, that, at high concentrations, impaired the capacity of T cells to engage in glycolysis and to generate regulatory T cells. Thus, the loss of these immunoregulatory circuits during COPD determined the hyperactivation of effector T cells that amplified inflammation, leading to progressive decline of lung function. Understanding these immunometabolic mechanisms can have important implications for monitoring COPD progression and for disease treatment.

Chronic obstructive pulmonary disease (COPD) is an inflammatory condition associated with abnormal immune responses, leading to airflow obstruction. Lungs of COPD subjects show accumulation of proinflammatory T helper (Th) 1 and Th17 cells resembling that of autoreactive immune responses. As regulatory T (T_reg) cells play a central role in the control of autoimmune responses and their generation and function are controlled by the adipocytokine leptin, we herein investigated the association among systemic leptin overproduction, reduced engagement of glycolysis in T cells, and reduced peripheral frequency of T_reg cells in different COPD stages. These phenomena were also associated with an impaired capacity to generate inducible T_reg (iT_reg) cells from conventional T (T_conv) cells. At the molecular level, we found that leptin inhibited the expression of forkhead-boxP3 (FoxP3) and its splicing variants containing the exon 2 (FoxP3-E2) that correlated inversely with inflammation and weakened lung function during COPD progression. Our data reveal that the immunometabolic pathomechanism leading to COPD progression is characterized by leptin overproduction, a decline in the expression of FoxP3 splicing forms, and an impairment in T_reg cell generation and function. These results have potential implications for better understanding the autoimmune-like nature of COPD and the pathogenic events leading to lung damage.

Impact of reduced pulmonary function in the Japanese general population: Lessons from the Yamagata-Takahata study

Regional epidemiological studies for respiratory diseases have been rarely performed in Japan, because spirometry is not regularly conducted in the standard annual health checks. The Yamagata-Takahata Study is an epidemiological study utilizing regional characteristics based on the 21st Century Centers of Excellence (COE) Program and the Global COE Program. Spirometric examination and other specific measurements via blood sampling were performed for the study participants in annual health check-ups held in Takahata, a town in Yamagata Prefecture. The Yamagata-Takahata Study revealed the impact of cigarette smoking habit on pulmonary function, the impact of reduced pulmonary function on mortality, and the situation regarding COPD comorbidities in Japan. Additionally, the study identified biomarkers of decline in pulmonary function among active smokers, and the risk factors for respiratory mortality in Japan. In this review, we summarize the findings of the Yamagata-Takahata study regarding the association between lower pulmonary function and the clinical characteristics of a Japanese general population.

Factors Associated With Progression of Lung Function Abnormalities in HIV-Infected Individuals

BACKGROUND

HIV is an independent risk factor for chronic obstructive pulmonary disease; however, baseline risk factors for lung function decline remain largely unknown in this population.

METHODS

HIV-infected participants in the Pittsburgh Lung HIV Cohort with at least 3 pulmonary function measurements between 2007 and 2016 were included. Pulmonary function testing including postbronchodilator (BD) spirometry and diffusion capacity for carbon monoxide (DLco) was performed every 18 months. We used a mixed-effect linear model to evaluate factors associated with pulmonary function testing and DLco decline and logistic regression models to evaluate factors associated with rapid FEV1 decline (defined as >80 mL per year) and any DLco decline.

RESULTS

Two hundred eighty-five HIV-infected participants were included. Median baseline CD4 cell count was 521 cells per micro liter, 61.9% had an undetectable HIV viral load at baseline, and 78.5% were receiving ART. Approximately 20% of participants met Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria for a diagnosis of chronic obstructive pulmonary disease at baseline. Older age and baseline GOLD stage 1 compared with stage 0 were associated with faster decline in post-BD FEV1%, whereas female sex was associated with slower decline. Similarly, female sex was associated with slower decline in DLco%. HIV-related factors including CD4 cell count, viral load, and ART use were not significantly associated with pulmonary function decline.

CONCLUSIONS

Older age, male sex, and higher baseline GOLD stage were associated with more rapid post-BD FEV1% decline in HIV-infected individuals.

Association of adiponectin/leptin ratio with carbohydrate and lipid metabolism parameters in HIV-infected patients during antiretroviral therapy

BACKGROUND

Adiponectin and leptin are adipose tissue hormones that regulate important lipid and glucose metabolic pathways. Our objective was to evaluate the interplay of these hormones described by the adiponectin/leptin ratio (ALR) in correlation to lipid and carbohydrate metabolism parameters in nondiabetic HIV-infected patients during antiretroviral therapy (ART).

MATERIALS AND METHODS

We enrolled consecutive nondiabetic patients with confirmed HIV infection, undergoing stable ART regimens for at least six months. Blood samples were collected and tested for immunological and virological parameters, adiponectin and leptin, fasting insulin, fasting plasma glucose, fasting triglycerides, total cholesterol, LDL cholesterol, and HDL cholesterol. ALR was computed for each patient. Resistance to insulin was assessed by calculating the Quantitative Insulin Sensitivity Check Index (QUICKI).

RESULTS

We enrolled 87 HIV-infected persons, with a mean age of 31.7 years (range: 18-65), including 47 men (mean age = 32.8 years) and 40 women (mean age = 30.5 years). The median value of ALR was 6.8 (interquartile range - IQR = 17.1). In male patients, ALR was inversely associated with the serum level of triglycerides (R = 0.285, p = 0.05), total cholesterol (R = 0.326, p = 0.02), and LDL cholesterol (R = 0.298, p = 0.04). Also for the male cohort, an increase in ALR seemed to improve insulin sensitivity (R = 0.323, p = 0.02) and serum HDL cholesterol (R = 0.597, p = 0.01). None of these correlations were observed in HIV-infected women.

CONCLUSION

Adiponectin and leptin seem to play important but different gender-specific roles in the pathogenesis of lipid and glucose metabolism of HIV-infected patients undergoing antiretroviral therapy.

ABBREVIATIONS

ALR, adiponectin/leptin ratio; BMI, body mass index; LDL, low-density lipoprotein; HDL, high-density lipoprotein; QUICKI, Quantitative Insulin Sensitivity Check Index.

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.

Plasma Leptin and Reduced FEV1 and FVC in Chronic Spinal Cord Injury

BACKGROUND

Adipose tissue produces leptin, which is pro-inflammatory, and adiponectin, which has anti-inflammatory properties. Participants with chronic spinal cord injury (SCI) have increased body fat and are at increased risk for respiratory illness.

OBJECTIVE

To assess the associations between leptin and adiponectin with pulmonary function in a chronic SCI cohort.

DESIGN

Cross-sectional study.

SETTING

Veterans Affairs Medical Center.

PARTICIPANTS

A total of 285 participants (237 men and 48 women) with chronic SCI with mean (standard deviation) injury duration 17.8 (13.2) years from the VA Boston and the community participating in an epidemiologic study assessing factors associated with respiratory health.

METHODS

Participants (24.6% cervical American Spinal Injury Association Impairment Scale (AIS) level A, B, and C; 33.6% other AIS A, B, and C; 41.8% AIS D) provided a blood sample, completed a respiratory health questionnaire, and underwent spirometry. Linear regression methods were used to assess cross-sectional associations between plasma leptin and adiponectin with spirometric measures of pulmonary function adjusted for age, race, gender, and height. Level and severity of SCI, mobility mode, body mass index, smoking, chronic obstructive pulmonary disease, asthma, chest injury history, laboratory batch, and other potential confounders were also considered.

MAIN OUTCOME MEASUREMENTS

forced expiratory volume in 1 second (FEV₁), forced vital capacity (FVC), and FEV₁/FVC.

RESULTS

There was a statistically significant inverse relationship between plasma leptin assessed in quartiles or as a continuous covariate with FEV₁ and FVC. In fully adjusted models, each interquartile range (16,214 pg/mL) increase in leptin was associated with a significant decrease in FEV₁ (-93.1 mL; 95% confidence interval = -166.2, -20.0) and decrease in FVC (-130.7 mL; 95% confidence interval = -219.4, -42.0). There were no significant associations between leptin and FEV₁/FVC or between plasma adiponectin with FEV₁, FVC, or FEV₁/FVC.

CONCLUSION

Plasma leptin in individuals with chronic SCI is inversely associated with FEV₁ and FVC, independently of SCI level and severity and other covariates. This finding suggests that plasma leptin may contribute to reduced pulmonary function in chronic SCI.

LEVEL OF EVIDENCE

II.

Serum Proteins Associated with Emphysema Progression in Severe Alpha-1 Antitrypsin Deficiency

Computed tomography (CT) lung density is an accepted biomarker for emphysema in alpha-1 antitrypsin deficiency (AATD), although concerns for radiation exposure limit its longitudinal use. Serum proteins associated with emphysema, particularly in early disease, may provide additional pathogenic insights. We investigated whether distinct proteomic signatures characterize the presence and progression of emphysema in individuals with severe AATD and normal forced expiratory volume in 1 second (FEV₁). QUANTitative lung CT UnMasking emphysema progression in AATD (QUANTUM-1) is a multicenter, prospective 3-year study of 49 adults with severe AATD and FEV₁ post-bronchodilator values (Post-BD) ≥ 80% predicted. All participants received chest CT, serial spirometry, and contributed to the serum biobank. Volumetric imaging display and analysis (VIDA) software defined the baseline 15^th percentile density (PD15) which was indexed to CT-derived total lung capacity (TLC). We measured 317 proteins using a multiplexed immunoassay (Myriad Discovery MAP^® panel) in 31 individuals with a complete dataset. We analyzed associations between initial PD15/TLC, PD15/TLC annual decline, body mass index (BMI), and protein levels using Pearson's product moment correlation. C-reactive protein (CRP), adipocyte fatty acid-binding protein (AFBP), leptin, and tissue plasminogen activator (tPA) were found to be associated with baseline emphysema and all but leptin were associated with emphysema progression after adjustments were made for age and sex. All 4 proteins were associated with BMI after further adjustment for multiple comparisons was made. The relationship between these proteins and BMI, and further validation of these findings in replicative cohorts require additional studies.

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).

Risk factors for FEV1 decline in mild COPD and high-risk populations

Background

Early diagnosis of COPD is often not achieved due to limited recognition and limited access to the pulmonary function test. Our hypothesis was that lung function decline may be different between populations with mild COPD and those who are at high risk and do not receive treatment.

Patients and methods

Subjects with mild COPD and those from a high-risk COPD population were recruited from a community-based COPD epidemiological study after obtaining consent. Baseline clinical characteristics, symptom questionnaire, spirometry, low-dose computed tomography (LDCT) chest scan, and blood plasma biomarker data were collected initially and then 1 year later.

Results

A total of 617 participants were recruited, and 438 eventually completed the first-year follow-up visit; 72 participants (46 males) were in the mild COPD group, and 225 participants (165 males) were in the high-risk group. The mean forced expiratory volume in the first second of expiration (FEV₁) decline in the mild COPD group was 129 mL, which was significantly higher than the 30 mL decline in the high-risk population group (P=0.005). Group category (odds ratio [OR] =0.230) and COPD Assessment Test (CAT) score (OR =9.912) were independent risk factors for an FEV₁% predicted decline of >15% for all participants. In the mild COPD group, patients with a higher CAT (OR =5.310) and Emphysema Index (OR =5.681) were associated with a FEV₁% predicted decline of >15% at the first-year follow-up. No factor showed a significantly predictive effect on FEV₁ decline in the high-risk COPD group.

Conclusion

Group category was an independent influential factor associated with FEV₁ decline.

The burden of obesity in asthma and COPD: Role of adiponectin

The influence of obesity on development, severity and prognosis of both asthma and COPD is attracting growing interest. The impact of obesity on the respiratory system ranges from structural modifications (decline of total lung capacity) to humoral alterations. Adipose tissue strongly contributes to the establishment of an inflammatory state being an important source of adipokines. Amongst adipokines, adiponectin is an important component of organ cross talk with adipose tissue exerting protective effects on a variety of pathophysiological processes. Adiponectin is secreted in serum where it abundantly circulates as complexes of different molecular weight. Adiponectin properties are mediated by specific receptors that are widely expressed with AdipoR1, AdipoR2, and T-cadherin being present on epithelial and endothelial pulmonary cells indicating a functional role on lung physiology. In COPD, mild to moderate obesity has been shown to have protective effects on patient's survival, while a higher mortality rate has been observed in patients with low BMI. A specific cluster of obese patients has been identified; in this group, asthma features are particularly severe and difficult to treat. Better understanding of the molecular mechanisms at the base of cross talk among different tissues and organs will lead to identification of new targets for both diagnosis and treatment of asthma and COPD.

Association of plasma adipokines with chronic obstructive pulmonary disease severity and progression

RATIONALE

Two adipokines, leptin and adiponectin, regulate metabolic and inflammatory systems reciprocally. The role of adiponectin in chronic obstructive pulmonary disease (COPD) has been studied. However, there are few data evaluating the relationship of plasma leptin with COPD severity or progression.

OBJECTIVES

The objective of this study was to evaluate the relationship of leptin, adiponectin, and the leptin/adiponectin ratio with COPD severity and progression according to COPD phenotypes.

METHODS

Plasma leptin and adiponectin levels were measured in 196 subjects with COPD selected from the Korean Obstructive Lung Disease cohort. Using a linear regression model and mixed linear regression, we determined the relationship of plasma leptin and adiponectin levels and the leptin/adiponectin ratio to COPD severity and progression over 3 years.

MEASUREMENTS AND MAIN RESULTS

The concentration of adiponectin in plasma positively correlated with percent emphysema on initial computed tomography (CT) (adjusted P = 0.022), whereas plasma leptin concentrations and the leptin/adiponectin ratio exhibited a significant inverse correlation with initial FEV1 (adjusted P = 0.013 for leptin and adjusted P = 0.041 for leptin/adiponectin ratio). Increased plasma leptin and leptin/adiponectin ratio were significantly associated with change in percent emphysema over 3 years (adjusted P = 0.037 for leptin and adjusted P = 0.029 for leptin/adiponectin ratio), whereas none of the adipokines demonstrated an association with FEV1 decline over the 3-year period.

CONCLUSIONS

Plasma adiponectin and leptin vary according to COPD phenotypes. Plasma leptin and the leptin/adiponectin ratio, but not adiponectin, were significantly associated with changes in CT-assessed emphysema, suggesting a potential role as a biomarker in emphysema progression in 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.