[Show abstract][Hide abstract] ABSTRACT: Background:
Conventional spirometric parameters have shown poor correlation with symptoms and health status of chronic obstructive pulmonary disease (COPD). While it is well-known that the pattern of the expiratory flow-volume curve (EFVC) represents ventilatory dysfunction, little attempts have been made to derive quantitative parameters by analyzing the curve. In this study, we aimed to derive useful parameters from EFVC via graphic analysis and tried to validate them in patients with COPD.
Using Graphical Analysis 3.4 Vernier Software, we derived from the EFVC such parameters as area of obstruction (Ao), area of triangle (AT), area of rectangle (AR) and ratio of volume at 75 and 25 % peak expiratory flow (PEF) (0.25/0.75 V). For validation, we reviewed clinical and spirometric data of 61 COPD patients from Seoul National University Airway Registry (SNUAR) and Korean obstructive Lung Disease (KOLD) cohorts.
Of all parameters, only RV/TLC significantly correlated with scores from St. George's Respiratory Questionnaire (SGRQ) (r = 0.447, p = 0.037). Six-minute walking distance (6MWD) highly correlated with Ao/AR (r = -0.618, p = 0.005) and Ao/PEF (r = -0.581, p = 0.009) whereas neither FEV1 nor FEV1/FVC had significant correlation with 6MWD.
Ao/AR and Ao/PEF are promising parameters which correlate well with the exercising capacity of COPD patients.
Preview · Article · Dec 2016 · BMC Pulmonary Medicine
[Show abstract][Hide abstract] ABSTRACT: Background:
The purpose of this study was to document outcomes following withdrawal of a single inhaler (step-down) in chronic obstructive pulmonary disease (COPD) patients on triple therapy (long-acting muscarinic antagonist and a combination of long-acting β2-agonists and inhaled corticosteroid), which a common treatment strategy in clinical practice.
Through a retrospective observational study, COPD patients receiving triple therapy over 2 years (triple group; n=109) were compared with those who had undergone triple therapy for at least 1 year and subsequently, over 9 months, initiated inhaler withdrawal (step-down group, n=39). The index time was defined as the time of withdrawal in the stepdown group and as 1 year after the start of triple therapy in the triple group.
Lung function at the index time was superior and the previous exacerbation frequency was lower in the stepdown group than in the triple group. Step-down resulted in aggravating disease symptoms, a reduced overall quality of life, decreasing exercise performance, and accelerated forced expiratory volume in 1 second (FEV1) decline (54.7±15.7 mL/yr vs. 10.7±7.1 mL/yr, p=0.007), but there was no observed increase in the frequency of exacerbations.
Withdrawal of a single inhaler during triple therapy in COPD patients should be conducted with caution as it may impair the exercise capacity and quality of life while accelerating FEV1 decline.
Preview · Article · Jan 2016 · Tuberculosis and Respiratory Diseases
[Show abstract][Hide abstract] ABSTRACT: Background: COPD patients with increased airway eosinophilic inflammation show a favorable response to inhaled corticosteroids (ICS) in combination with a long-acting bronchodilator. Recent studies have demonstrated a significant correlation of sputum eosinophilia with blood eosinophils and periostin. We investigated whether high blood eosinophils and plasma periostin were associated with an improvement in forced expiratory volume in 1 second (FEV1) after 3-month treatment with ICS/long-acting beta2-agonist (LABA) in stable COPD patients. Patients and methods: Blood eosinophils and plasma periostin levels were measured in 130 stable COPD subjects selected from the Korean Obstructive Lung Disease cohort. Subjects began a 3-month ICS/LABA treatment after washout period. Results: High blood eosinophils (.260/μL, adjusted odds ratio =3.52, P=0.009) and high plasma periostin (.23 ng/mL, adjusted odds ratio =3.52, P=0.013) were significantly associated with FEV1 responders (.12% and 200 mL increase in FEV1 from baseline after treatment). Moreover, the addition of high blood eosinophils to age, baseline positive bronchodilator response, and FEV1,50% of the predicted value significantly increased the area under the curve for prediction of FEV1 responders (from 0.700 to 0.771; P=0.045). Conclusion: High blood eosinophils and high plasma periostin were associated with improved lung function after 3-month ICS/LABA treatment. In particular, high blood eosinophils, in combination with age and baseline lung function parameters, might be a possible biomarker for identification of COPD patients with favorable FEV1 improvement in response to ICS/LABA treatment.
Preview · Article · Dec 2015 · International Journal of COPD
[Show abstract][Hide abstract] ABSTRACT: Background/Aims:
Idiopathic pulmonary arterial hypertension (IPAH) is an incurable disease with high mortality. Although most studies recommend anticoagulation treatment for IPAH, the benefits are uncertain, particularly in Korea, where it has not been studied. The purpose of this study was to evaluate survival outcomes of Korean patients with IPAH treated with warfarin.
We performed a retrospective cohort study of patients diagnosed previously with pulmonary arterial hypertension (PAH) at the Asan Medical Center in Korea, between January 1994 and February 2013. We excluded patients with associated PAH, patients who did not undergo right heart catheterization (RHC), and patients with a positive vasoreactivity test. Patients in the study cohort were classified into a “warfarin group” and a “non-warfarin group,” according to the treatment they received during the first year after diagnosis.
We identified 31 patients with IPAH and a negative vasoreactivity test on RHC. Median patient age was 36.0 years, and 23 patients (74.2%) were female. The median time from the onset of symptoms to diagnosis was 19.0 months, and the most common presenting symptom was dyspnea. Survival rates of the patients at 1, 3, 5, and 10 years were 90.2%, 79.5%, 62.7%, and 34.8%, respectively. The mean survival period was 12.0 years in the warfarin group and 6.1 years in the non-warfarin group. Warfarin treatment had significant survival benefits in patients with IPAH (p = 0.023).
Warfarin treatment substantially improved survival outcomes in Korean cases of IPAH.
No preview · Article · Oct 2015 · The Korean Journal of Internal Medicine
[Show abstract][Hide abstract] ABSTRACT: Background and objectiveTriple combination therapy with tiotropium plus budesonide/formoterol has improved lung function and reduced exacerbation risk in patients with chronic obstructive pulmonary disease (COPD) in Western countries, but no such data exist for East Asian patients. This study aimed to evaluate the efficacy and tolerability of adding budesonide/formoterol to tiotropium compared with tiotropium alone in East Asian patients with severe/very severe COPD.Methods
This 12-week, randomized, parallel-group, multicentre, open-label study was conducted in East Asia. After a 14-day run-in period during which patients received tiotropium 18 μg once daily, patients were randomized to tiotropium (18 μg once daily) + budesonide/formoterol (160/4.5 μg 2 inhalations twice daily) or tiotropium alone (18 μg once daily). The primary endpoint was change from baseline in pre-dose forced expiratory volume in 1 s (FEV1) to the mean of values measured at Weeks 1, 6 and 12.ResultsPre-dose FEV1 significantly increased from baseline with tiotropium plus budesonide/formoterol (n = 287) versus tiotropium alone (n = 291) (5.0% vs 0.6%; treatment difference: 4.4% (95% CI: 1.9–6.9), P = 0.0004). Triple therapy also reduced the COPD exacerbation rate by 40.7% (P = 0.0032) and prolonged time to first exacerbation (38.6% risk reduction, P = 0.0167) versus tiotropium alone and markedly improved health-related quality of life (HRQoL), measured using the St George's Respiratory Questionnaire. Incidence of adverse events was 26% for both groups.Conclusions
In East Asian patients with severe/very severe COPD, adding budesonide/formoterol to tiotropium was associated with significant improvements in FEV1 and HRQoL and lower COPD exacerbation rates. Treatment was generally well tolerated.Clinical trial registration: NCT01397890 at Clinicaltrials.gov
[Show abstract][Hide abstract] ABSTRACT: Background:
Since the Global Initiative for Chronic Obstructive Lung Disease (GOLD) groups A-D were introduced, the lung function changes according to group have been evaluated rarely.
We investigated the rate of decline in annual lung function in patients categorized according to the 2014 GOLD guidelines.
Patients with COPD included in the Korean Obstructive Lung Disease (KOLD) prospective study, who underwent yearly postbronchodilator spirometry at least three times, were included. The main outcome was the annual decline in postbronchodilator forced expiratory volume in 1 second (FEV1), which was analyzed by random-slope and random-intercept mixed linear regression.
A total 175 participants were included. No significant postbronchodilator FEV1 decline was observed between the groups (-34.4±7.9 [group A]; -26.2±9.4 [group B]; -22.7±16.0 [group C]; and -24.0±8.7 mL/year [group D]) (P=0.79). The group with less symptoms (-32.3±7.2 vs -25.0±6.5 mL/year) (P=0.44) and the low risk group (-31.0±6.1 vs -23.6±7.7 mL/year) (P=0.44) at baseline showed a more rapid decline in the postbronchodilator FEV1, but the trends were not statistically significant. However, GOLD stages classified by FEV1 were significantly related to the annual lung function decline.
There was no significant difference in lung function decline rates according to the GOLD groups. Prior classification using postbronchodilator FEV1 predicts decline in lung function better than does the new classification.
Preview · Article · Sep 2015 · International Journal of COPD
[Show abstract][Hide abstract] ABSTRACT: The prognostic role of resting pulmonary hyperinflation as measured by residual volume (RV)/total lung capacity (TLC) in chronic obstructive pulmonary disease (COPD) remains poorly understood. Therefore, this study aimed to identify the factors related to resting pulmonary hyperinflation in COPD and to determine whether resting pulmonary hyperinflation is a prognostic factor in COPD. In total, 353 patients with COPD in the Korean Obstructive Lung Disease cohort recruited from 16 hospitals were enrolled. Resting pulmonary hyperinflation was defined as RV/TLC ≥ 40%. Multivariate logistic regression analysis demonstrated that older age (P = 0.001), lower forced expiratory volume in 1 second (FEV1) (P < 0.001), higher St. George Respiratory Questionnaire (SGRQ) score (P = 0.019), and higher emphysema index (P = 0.010) were associated independently with resting hyperinflation. Multivariate Cox regression model that included age, gender, dyspnea scale, SGRQ, RV/TLC, and 6-min walking distance revealed that an older age (HR = 1.07, P = 0.027), a higher RV/TLC (HR = 1.04, P = 0.025), and a shorter 6-min walking distance (HR = 0.99, P < 0.001) were independent predictors of all-cause mortality. Our data showed that older age, higher emphysema index, higher SGRQ score, and lower FEV1 were associated independently with resting pulmonary hyperinflation in COPD. RV/TLC is an independent risk factor for all-cause mortality in COPD.
Full-text · Article · Sep 2015 · Journal of Korean Medical Science
[Show abstract][Hide abstract] ABSTRACT: Endobronchial valve (EBV) therapy is increasingly being seen as a therapeutic option for advanced emphysema, but its clinical utility in Asian populations, who may have different phenotypes to other ethnic populations, has not been assessed.
This prospective open-label single-arm clinical trial examined the clinical efficacy and the safety of EBV in 43 consecutive patients (mean age 68.4±7.5, forced expiratory volume in 1 second [FEV1] 24.5%±10.7% predicted, residual volume 208.7%±47.9% predicted) with severe emphysema with complete fissure and no collateral ventilation in a tertiary referral hospital in Korea.
Compared to baseline, the patients exhibited significant improvements 6 months after EBV therapy in terms of FEV1 (from 0.68±0.26 L to 0.92±0.40 L; P<0.001), 6-minute walk distance (from 233.5±114.8 m to 299.6±87.5 m; P=0.012), modified Medical Research Council dyspnea scale (from 3.7±0.6 to 2.4±1.2; P<0.001), and St George's Respiratory Questionnaire (from 65.59±13.07 to 53.76±11.40; P=0.028). Nine patients (20.9%) had a tuberculosis scar, but these scars did not affect target lobe volume reduction or pneumothorax frequency. Thirteen patients had adverse events, ten (23.3%) developed pneumothorax, which included one death due to tension pneumothorax.
EBV therapy was as effective and safe in Korean patients as it has been shown to be in Western countries. (
Preview · Article · Aug 2015 · International Journal of COPD
[Show abstract][Hide abstract] ABSTRACT: 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.
The objective of this study is to evaluate the relationship of leptin, adiponectin, and leptin/adiponectin ratio with the COPD severity and progression according to COPD phenotypes.
Plasma leptin and adiponectin levels were measured in 196 COPD subjects 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 leptin/adiponectin ratio with COPD severity and progression over 3 years.
The concentration of adiponectin in plasma positively correlated with percent (%) emphysema on initial computed tomography (CT) (adjusted P = 0.022), while plasma leptin concentrations and leptin/adiponectin ratio exhibited an independent inverse correlation with initial forced expiratory volume in 1 second (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 % emphysema over 3 years (adjusted P = 0.037 for leptin and adjusted P = 0.029 for leptin/adiponectin ratio), while none of the adipokines demonstrated an association with FEV1 decline over the 3 year period.
Plasma adiponectin and leptin vary according to COPD phenotypes. Plasma leptin and 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 COPD patients.
No preview · Article · May 2015 · Annals of the American Thoracic Society
[Show abstract][Hide abstract] ABSTRACT: Background:
Although smoking is the most important and modifiable cause of chronic obstructive pulmonary disease (COPD), other risk factors including asthma and tuberculosis (TB) are also associated. It is common for COPD patients to have more than one of these risk factors. The aims of this study were to determine the prevalence of airflow limitation (FEV1/FVC<0.7) according to the risk factors and to investigate their impact and interaction in airflow limitation.
From the Korean National Health and Nutrition Examination Survey between 2008 and 2012, we analyzed participants over 40 years of age by spirometry, chest radiograph and questionnaire about asthma and smoking history.
Of 12,631 participants, 1,548 (12.3%) had airflow limitation. The prevalence of airflow limitation in smokers (≥10 pack-year), asthmatics, and those with inactive TB was 23.9%, 32.1%, and 33.6%. The prevalence increased with the number of risk factors: 86.1% had airflow limitation if they had all three risk factors. Impacts of inactive TB and asthma on airflow limitation were equivalent to 47 and 69 pack-years of smoking, respectively. Airflow limitation resulted from lower levels of smoking in those with inactive TB and asthma. A potential interaction between smoking and inactive tuberculosis in the development of airflow limitation was identified (p = 0.054).
Asthma and inactive TB lesions increase susceptibility to smoking in the development of airflow limitation. People with these risk factors should be seen as a major target population for anti-smoking campaigns to prevent COPD.
[Show abstract][Hide abstract] ABSTRACT: Background and Objectives. Chronic obstructive pulmonary disease (COPD) is a complex disease characterized by airflow limitation. Although airway inflammation and oxidative stress are known to be important in the pathogenesis of COPD, the mechanism underlying airflow obstruction is not fully understood. Gene expression profiling of lung tissue was performed to define the molecular pathways that are dysregulated in COPD. Methods. RNA was isolated from lung tissues obtained from 98 subjects with COPD and 91 control subjects with normal spirometry. The RNA samples were processed with RNA-seq using the HiSeq 2000 system. Genes expressed differentially between the two groups were identified using Student's t-test. Results. After filtering for genes with zero counts and noncoding genes, 16,676 genes were evaluated. A total of 2312 genes were differentially expressed between the lung tissues of COPD and control subjects (false discovery rate corrected q < 0.01). The expression of genes related to oxidative phosphorylation and protein catabolism was reduced and genes related to chromatin modification were dysregulated in lung tissues of COPD subjects. Conclusions. Oxidative phosphorylation, protein degradation, and chromatin modification were the most dysregulated pathways in the lung tissues of COPD subjects. These findings may have clinical and mechanistic implications in COPD.
Preview · Article · Apr 2015 · International Journal of Genomics
[Show abstract][Hide abstract] ABSTRACT: AMP-activated protein kinase (AMPK) not only functions as an intracellular energy sensor and regulator, but is also a general sensor of oxidative stress. Furthermore, there is recent evidence that it participates in limiting acute inflammatory reactions, apoptosis and cellular senescence. Thus, it may oppose the development of chronic obstructive pulmonary disease.
To investigate the role of AMPK in cigarette smoke-induced lung inflammation and emphysema we first compared cigarette smoking and polyinosinic-polycytidylic acid [poly(I:C)]-induced lung inflammation and emphysema in AMPKα1-deficient (AMPKα1-HT) mice and wild-type mice of the same genetic background. We then investigated the role of AMPK in the induction of interleukin-8 (IL-8) by cigarette smoke extract (CSE) in A549 cells.
Cigarette smoking and poly(I:C)-induced lung inflammation and emphysema were elevated in AMPKα1-HT compared to wild-type mice. CSE increased AMPK activation in a CSE concentration- and time-dependent manner. 5-Aminoimidazole-4-carboxamide-1-β-4-ribofuranoside (AICAR), an AMPK activator, decreased CSE-induced IL-8 production while Compound C, an AMPK inhibitor, increased it, as did pretreatment with an AMPKα1-specific small interfering RNA.
AMPKα1-deficient mice have increased susceptibility to lung inflammation and emphysema when exposed to cigarette smoke, and AMPK appears to reduce lung inflammation and emphysema by lowering IL-8 production.
Preview · Article · Jan 2015 · Tuberculosis and Respiratory Diseases