Components of the Chronic Obstructive Pulmonary Disease Assessment Test Associated with the Exacerbation of Severe Chronic Obstructive Pulmonary Disease Patients.

INTRODUCTION: The chronic obstructive pulmonary disease (COPD) Assessment Test (CAT) score is widely used for evaluating the health status of patients diagnosed with COPD. The aim of this study was to identify which components of the CAT are associated with exacerbations in severe COPD patients. METHODS: Using data from the Korean COPD Subgroup Study (KOCOSS), we identified 3,440 COPD patients, among which 1,027 patients are classified as having severe COPD based on spirometry results. The CAT scores on 8 items were evaluated and classified into respiratory and non-respiratory categories. We analyzed the association between CAT item scores and moderate-to-severe exacerbations during study enrollment and the following years. RESULTS: Patients with a history of moderate-to-severe exacerbations had higher scores on non-respiratory CAT components. Longitudinal CAT scores on all items after enrollment were higher in the moderate-to-severe exacerbation group. Additionally, the frequency of severe exacerbations was associated with specific CAT components related to limited activities, confidence leaving home, sleeplessness, and energy. CONCLUSIONS: This study revealed that the non-respiratory CAT component scores were statistically significant factors for predicting the moderate-to-severe exacerbation of severe COPD patients. Non-respiratory symptoms and functional limitations should be considered in patients with severe COPD. Interventions, such as pulmonary rehabilitation, may be needed to improve patients' overall well-being and prevent exacerbations.

Isolated respiratory tract microorganisms and clinical characteristics in asthma exacerbation of obese patients: a multicenter study.

BACKGROUND: Viral infection is a risk factor for asthma exacerbation (AE). However, bacterial infections related to AE in adults are poorly known. On the other hand, obese patients with asthma have their own clinical and biological characteristics compared with non-obese patients. METHODS: We investigated the differences in isolated pathogens for AE between obese and non-obese patients with asthma. We included 407 patients with AE from 24 medical centers in Korea. Microorganisms isolated from culture, RT-PCR or serologic tests using lower respiratory tract specimens were retrospectively investigated. RESULTS: A total of 171 obese and 236 non-obese patients with asthma were included for analysis. Compared to non-obese patients, obese patients were associated with women (77.2% vs. 63.6%), never smoker (82.5% vs. 73.9%), shorter duration of asthma (7.9 ± 8.4 vs. 10.5 ± 10.1 years), less history of pulmonary tuberculosis (8.8% vs. 17.4%), and more comorbidity of allergic rhinitis (48.5% vs. 0.8%). Viral and/or bacterial infections were detected in 205 patients (50.4%) with AE. The numbers of patients with viral only, bacterial only, or both infections were 119, 49, and 37, respectively. The most commonly isolated bacterium was Streptococcus pneumoniae, followed by Pseudomonas aeruginosa and Chlamydia pneumoniae. Obese patients showed a lower incidence of Chlamydia pneumoniae infection. In the non-obese group, bacterial infection, especially Chlamydia pneumoniae infection, was significantly associated with the duration of systemic corticosteroid use (13.6 ± 19.8 vs. 9.7 ± 6.7 days, p = 0.049). CONCLUSION: Bacterial infection was associated with a longer period of corticosteroid use in the non-obese group. Acute Chlamydia pneumoniae infection was less associated with obese patients with AE. Further well-designed studies are needed to evaluate microorganisms and the efficacy of antibiotics in patients with AE.

Spirometric Interpretation and Clinical Relevance According to Different Reference Equations.

BACKGROUND: Global Lung Function Initiative (GLI)-2012 reference equation is currently suggested for interpretation of spirometry results and a new local reference equation has been developed in South Korea. However, lung function profiles according to the different reference equations and their clinical relevance have not been identified in chronic obstructive pulmonary disease (COPD) patients. METHODS: Our cross-sectional study evaluated Choi's, Korean National Health and National Examination Survey (KNHANES)-VI, and GLI-2012 reference equations. We estimated the percentages of predictive forced expiratory volume in one second (FEV1) and airflow limitation severity according to reference equations and analyzed their associations with patient reported outcomes (PROs): COPD assessment test (CAT) score, St. George's Respiratory Questionnaire for COPD patients (SGRQ-C) score, and six minute walk distance (6MWD). RESULTS: In the eligible 2,180 COPD patients, lower predicted values of FEV1 and forced vital capacity (FVC) were found in GLI-2012 compared to Choi's and KNHANES-VI equations. GLI-2012 equation resulted in a lower proportion of patients being classified as FEV1 < 80% or FVC < 80% compared to the other equations. However, the Z-scores of FEV1 and FVC were similar between the KNHANES-VI and GLI-2012 equations. Three reference equations exhibited significant associations between FEV1 (%) and patient-reported outcomes (CAT score, SGRQ-C score, and 6MWD). CONCLUSION: GLI-2012 reference equation may not accurately reflect FEV1 (%) in the Korean population, but the Z-score using GLI-2012 equation can be a viable option for assessing FEV1 and airflow limitation in COPD patients. Similar to the other two equations, the GLI-2012 equation demonstrated significant associations with PROs.

Recent Prevalence of and Factors Associated With Chronic Obstructive Pulmonary Disease in a Rapidly Aging Society: Korea National Health and Nutrition Examination Survey 2015-2019.

BACKGROUND: The prevalence of chronic obstructive pulmonary disease (COPD) increases with age, and aging is an important risk factor for COPD development. In the era of global aging, demographic information about the prevalence of and factors associated with COPD are important to establish COPD care plans. However, limited information is available in rapidly aging societies, including Korea. METHODS: We conducted a cross-sectional observational study using Korea National Health and Nutrition Examination Survey data from 2015-2019. We included 15,613 participants and analyzed trends of and factors associated with COPD. RESULTS: During the study period, the overall prevalence of COPD was 12.9%. Over five years, the yearly prevalence of COPD was fairly constant, ranging from 11.5% to 13.6%. Among individuals aged ≥ 70 years, nearly one-third met COPD diagnostic criteria. In the multivariable analysis, age 70 years or older was the most strong factor associated with COPD (adjusted odds ratio [aOR], 17.86; 95% confidence interval [CI], 14.16-22.52; compared with age 40-49), followed by asthma (aOR, 3.39; 95% CI, 2.44-4.71), male sex (aOR, 2.64; 95% CI, 2.18-3.19), and current smokers (aOR, 2.60; 95% CI, 2.08-3.25). Additionally, ex-smokers, low income, decreased forced expiratory volume in 1 second %pred, and a history of pulmonary tuberculosis were associated with COPD. On the other hand, body mass index (BMI) ≥ 25 kg/m² (aOR, 0.62; 95% CI, 0.54-0.71; compared with BMI 18.5-24.9 kg/m²) had an inverse association with COPD. CONCLUSION: Recent trends in the prevalence of COPD in South Korea are relatively stable. Approximately one-third of participants aged 70 years and older had COPD. Aging was the most important factor associated with COPD.

Association of body mass index and COPD exacerbation among patients with chronic bronchitis.

BACKGROUND AND OBJECTIVE: Chronic obstructive pulmonary disease (COPD) patients with a body mass index (BMI) < 25 kg/m2 are prone to develop adverse event of pharmacological treatment for frequent exacerbation. As chronic bronchitis (CB) is one of the strong risk factors of exacerbation, we investigated the associations between BMI and COPD exacerbations in patients with CB. METHODS: Patients with COPD were included from the Korean COPD Subgroup Study (KOCOSS), a multicenter observational cohort study. CB was defined using the St. George's Respiratory Questionnaire and the participants were categorized according to BMI cut-off of 25 kg/m2. Exacerbations during a 1-year follow-up were compared among four groups: non-CB with BMI ≥ 25 kg/m2, non-CB with BMI < 25 kg/m2, CB with BMI ≥ 25 kg/m2, and CB with BMI < 25 kg/m2. RESULTS: Among the 1264 patients with COPD, 451 (35.7%) had CB and 353 (27.9%) had both CB and BMI < 25 kg/m2. The COPD exacerbation risk increased across the non-CB with BMI < 25 kg/m2, CB with BMI ≥ 25 kg/m2, and CB with BMI < 25 kg/m2 groups (adjusted incidence rate ratio [95% confidence interval] 1.21 [0.89-1.62], 1.20 [0.77-1.88], and 1.41 [1.02-1.91], respectively, compared to the non-CB with BMI ≥ 25 kg/m2 group). CONCLUSIONS: COPD patients having both CB and a BMI < 25 kg/m2 are at higher risk of exacerbations. Considering that a BMI < 25 kg/m2 often limits treatment options preventing exacerbations, modified guidelines might be needed for non-obese CB patients in Asia.

Incidence and outcomes of adverse drug reactions to first-line anti-tuberculosis drugs and their effects on the quality of life: A multicenter prospective cohort study.

BACKGROUND: In tuberculosis (TB) treatment, adverse drug reactions (ADRs) can interrupt treatment and decrease the quality of life (QoL). We aimed to prospectively investigate the incidence of ADRs to first-line anti-TB drugs and related outcomes and QoL. METHODS: Adult patients with TB who had been treated with first-line anti-TB drugs in five Korean hospitals were enrolled. ADR questionnaire surveys and blood tests were performed four times serially, and QoL was assessed on the fourth TB treatment week (±2 weeks). RESULTS: Of 410 enrolled patients with TB (males, 62%; mean age, 52.1 ± 18.1 years [those aged ≥65 years, 26.6%]), 67.8% experienced any ADRs (≥ grade 2) to TB drugs. The most common ADR was fatigue (53.2%), followed by itching (42.7%) and anorexia (41.7%). Older adult patients experienced relatively more ADRs, including anorexia, dyspepsia, rash, dizziness, anemia, abnormal hepatic/renal function tests, and increased uric acid levels (p < 0.05). Treatment regimens changed for 9.5% of patients owing to ADRs to anti-TB drugs. Patients with any ADRs and older adult patients had significantly lower QoL than their counterparts (p < 0.05). Old age (odds ratio [OR], 1.02) and being male (OR 2.65) were independently associated with ADRs, whereas active smoking (OR 4.73) and a relatively long treatment phase (OR 5.13) were independently associated with hepatotoxicity. CONCLUSION: ADRs to first-line anti-TB drugs were common and related to relatively low QoL, especially among older adults. Although 9.5% of patients had ADR-related regimen changes, most patients with ADRs completed treatments successfully.

Risk Factors of Rapid FEV1 Decline in a Real-World Chronic Obstructive Pulmonary Disease Cohort.

BACKGROUND: Rapid forced expiratory volume in 1 s (FEV1) decliners have been considered a unique subgroup of patients with chronic obstructive pulmonary disease (COPD). Rapid FEV1 decline manifests early and is associated with poor prognosis. This necessitates the pre-emptive identification of risk factors for rapid FEV1 decline. OBJECTIVES: We aimed to determine the risk factors and clinical outcomes in patients with COPD. METHODS: This longitudinal, observational study was based on the Korea COPD Subgroup Study cohort (NCT02800499) from January 2012 to December 2019 across 54 medical centers in South Korea. Eligible patients were followed up for 3 years with serial spirometric tests. We calculated the annualized percentage change in FEV1 from baseline. Rapid decliners were defined as the quartile of patients with the highest annualized percentage FEV1 decline. RESULTS: Of the 518 patients, 130 were rapid decliners who lost 6.2%/year and 100 mL/year of FEV1. The multivariable logistic regression identified male sex, current smoking, blood eosinophil count <150/µL, and high forced vital capacity as the independent risk factors for rapid FEV1 decline. Among rapid decliners, the lung function deteriorated more rapidly in current smokers and patients with severe dyspnea, while triple combination therapy attenuated lung function decline in comparison with mono-bronchodilator therapy. Rapid decliners had a higher rate of severe exacerbation than nonrapid decliners (0.2/year vs. 0.1/year, p value = 0.032). CONCLUSIONS: We identified the independent risk factors for rapid FEV1 decline. This information may assist physicians in the early detection and pertinent management of rapid decline among patients with COPD.

Increased Healthcare Delays in Tuberculosis Patients During the First Wave of COVID-19 Pandemic in Korea: A Nationwide Cross-Sectional Study.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic caused disruptions to healthcare systems, consequently endangering tuberculosis (TB) control. We investigated delays in TB treatment among notified patients during the first wave of the COVID-19 pandemic in Korea. METHODS: We systemically collected and analyzed data from the Korea TB cohort database from January to May 2020. Groups were categorized as 'before-pandemic' and 'during-pandemic' based on TB notification period. Presentation delay was defined as the period between initial onset of symptoms and the first hospital visit, and healthcare delay as the period between the first hospital visit and anti-TB treatment initiation. A multivariate logistic regression analysis was performed to evaluate factors associated with delays in TB treatment. RESULTS: Proportion of presentation delay > 14 days was not significantly different between two groups (48.3% vs. 43.7%, P = 0.067); however, proportion of healthcare delay > 5 days was significantly higher in the during-pandemic group (48.6% vs. 42.3%, P = 0.012). In multivariate analysis, the during-pandemic group was significantly associated with healthcare delay > 5 days (adjusted odds ratio = 0.884, 95% confidence interval = 0.715-1.094). CONCLUSION: The COVID-19 pandemic was associated with healthcare delay of > 5 days in Korea. Public health interventions are necessary to minimize the pandemic's impact on the national TB control project.

Collateral effects of the coronavirus disease 2019 pandemic on lung cancer diagnosis in Korea.

BACKGROUND: The COVID-19 pandemic is predicted to significantly affect patients with lung cancer, owing to its rapid progression and high mortality. Studies on lung cancer diagnosis and treatment during an epidemic are lacking. We analyzed the impact of COVID-19 on lung cancer diagnosis in Korea, where lung cancer incidence continues to rise. METHODS: The number of newly diagnosed lung cancer cases in three university-affiliated hospitals during the pandemic and their clinical features were compared with lung cancer cases diagnosed during the same period in the past 3 years. The effectiveness of measures taken by the study hospitals to prevent nosocomial transmission was reviewed. RESULTS: A total of 612 patients were diagnosed with lung cancer from February through June, 2017-2020. During the pandemic, the number of patients who sought consultation at the division of pulmonology of study hospitals dropped by 16% from the previous year. Responding to the pandemic, the involved hospitals created physically isolated triage areas for patients with acute respiratory infection symptoms. Wide-range screening and preventive measures were implemented, thus minimizing the delay in lung cancer diagnosis. No patient acquired COVID-19 due to hospital exposure. The proportion of patients with stage III-IV non-small-cell lung cancer (NSCLC) significantly increased (2020: 74.7% vs. 2017: 57.9%, 2018: 66.7%, 2019: 62.7%, p = 0.011). The number of lung cancers diagnosed during this period and the previous year remained the same. CONCLUSIONS: The proportion of patients with advanced NSCLC increased during the COVID-19 pandemic.

Current Situation of Home Oxygen Therapy for Chronic Obstructive Pulmonary Disease Patients in Korea.

BACKGROUND: Long-term oxygen therapy provides various benefits, including prolonged survival for severely hypoxic chronic obstructive pulmonary disease (COPD) patients. However, adequate management strategies for home oxygen therapy are not well established in Korea. This study aimed to explore the current situation of home oxygen therapy to provide basic data for developing a strategy for COPD patients on home oxygen therapy. METHODS: In this cross-sectional study, we enrolled COPD patients using home oxygen therapy for at least 1 month. Face-to-face interviews were conducted, guided by a structured questionnaire about home oxygen therapy. RESULTS: A total of 195 patients were enrolled. The mean age was 72.6 ± 9.7 years, and 76.4% of patients were men. The mean modified Medical Research Council, COPD Assessment Test, and EuroQol-5D index scores were 3.4 ± 0.8, 29.7 ± 6.8, and 0.35 ± 0.44, respectively. At rest, patients were prescribed oxygen for 12.5 ± 7.3 hr/day and used 12.9 ± 8.5 hr/day on average. During exercise, the mean duration of prescribed oxygen was 6.6 ± 4.3 hr/day, and the actual use was 1.1 ± 2.9 hr/day. A total of 25.6% of patients used ambulatory oxygen; with financial burden the main reason for nonuse. The mean number of hospitalizations and emergency room visits were 2.5 and 2.6, respectively. CONCLUSION: This study revealed low adherence to home oxygen therapy, poor health-related quality of life, frequent hospitalizations, and a high financial burden among COPD patients using home oxygen therapy. The study highlights the need for adequate strategies to improve the quality of home oxygen therapy.

Thyroid transcription factor-1 as a prognostic indicator for stage IV lung adenocarcinoma with and without EGFR-sensitizing mutations.

BACKGROUND: Thyroid transcription factor (TTF)-1 expression is a diagnostic marker and a good prognostic indicator for lung adenocarcinoma. However, its good prognostic ability might be due to epidermal growth factor receptor (EGFR)-sensitizing mutations as shown by the positive correlation between TTF-1 expression and EGFR mutations. We explored the prognostic impact of TTF-1 expression according to EGFR-sensitizing mutation status in lung adenocarcinoma patients. METHODS: We conducted a retrospective cohort study of patients with stage IV lung adenocarcinoma. Data were extracted from the lung cancer registry of Hallym University Medical Centers (three hospitals) in Korea between March 2006 and March 2016. RESULTS: Overall, 173 patients were included. EGFR-sensitizing mutations were detected in 84 (51.4%) patients. TTF-1 expression was positive in 139 (80.3%) patients; it was significantly correlated with EGFR-sensitizing mutations (p < 0.001). TTF-1-positive lung adenocarcinoma patients had longer overall survival (OS) than those who were TTF-1 negative (19.3 vs. 5.8 months, p < 0.001). In a Cox regression analysis, TTF-1 positivity, Stage IV M1a, good performance status, and EGFR-sensitizing mutations were independently associated with prolonged OS. In the subgroup of wild-type EGFR adenocarcinoma patients, TTF-1 positivity was also a good prognostic indicator for OS and progression-free survival (PFS) after first-line cytotoxic chemotherapy. CONCLUSIONS: TTF-1 expression was a good prognostic indicator for OS and PFS in stage IV lung adenocarcinoma patients with and without EGFR-sensitizing mutations.

Outcome of Regular Inhaled Treatment in GOLD A Chronic Obstructive Pulmonary Disease Patients.

BACKGROUND: The 2017 Global Initiative for Chronic Obstructive Lung Disease (GOLD) recommends regular bronchodilator therapy in all group A patients with chronic obstructive pulmonary disease (COPD). OBJECTIVE: The aim of this study was to evaluate whether regular inhaled treatment in group A patients with COPD improves their health outcomes, including exacerbations and symptoms. METHODS: We recruited patients from 2 Korean prospective cohorts. Eligible COPD patients had a modified Medical Research Council (mMRC) dyspnea score of <2, a St. George's Respiratory Questionnaire for COPD (SGRQ-C) total score of <25, and had no more than 1 exacerbation and no hospitalizations during the previous year. Incidence rates of exacerbations and changes in symptom scores were analyzed. RESULTS: After propensity score matching, there were 107 patient pairs, with and without regular inhaled treatment, who were followed up for mean times of 2.6 and 3.1 years, respectively. The incidence rates of exacerbations in those with and without regular treatment were not significantly different (incidence rate ratio 1.24 [95% CI 0.68 to 2.25]). Significant differences in favor of regular treatment were observed at 6 and 12 months for the SGRQ-C total scores (mean between-group difference -4.7 [95% CI -7.9 to -1.6] and -4.8 [95% CI -7.9 to -1.7], respectively). Regular treatment with a long-acting bronchodilator was also associated with significantly better scores on the SGRQ-C (mean between-group difference -5.0 [95% CI -8.6 to -1.4]) compared to no regular treatment at 12 months of follow-up. CONCLUSIONS: Regular inhaled treatment in group A patients with COPD was associated with a symptomatic benefit but not with a reduction of exacerbation rates.

Validation of Previous Spirometric Reference Equations and New Equations.

BACKGROUND: Pulmonary functions are interpreted using predicted values from reference equations that vary with ethnicity, gender, age, height, and weight. The universally used Choi's reference equations are not validated for Korean populations, and the purpose of this study was to validate them and develop new reference equations. METHODS: Subjects with normal spirometry and chest radiographs, no co-morbidities, and non-smokers, from the Korean National Health and National Examination Survey (KNHANES)-VI were enrolled (n = 117). Intraclass correlation coefficient (ICC) was assessed for reliability of reference equations. New reference equations were developed using linear regression analysis. Differences between observed and predicted values were assessed to compare the reference equations from Choi's, Global Lung Function Initiative 2012, KNHANES-IV, and newly developed equations. RESULTS: The ICC of Choi's reference equations was 0.854 (P < 0.001). The new reference equations for men were: forced vital capacity (FVC) (L) = - 4.38775 - 0.01184 × age + 0.05547 × height, forced expiratory volume - 1 second (FEV1) (L) = - 2.40147 - 0.02134 × age + 0.04103 × height; and for women: FVC (L) = - 3.09063 + 0.003904 × age + 0.038694 × height; FEV1 (L) = - 1.32933 - 0.00872 × age + 0.02762 × height. The differences between the predicted and observed means were largest in Choi's equations, but lowest in the new equations with highest goodness of fit. CONCLUSION: Because Choi's reference equations presented larger differences from the observed values, despite reliability, and the new reference equations showed better goodness of fit, we suggest the latter for Korean populations.

Immunoglobulin G Subclass Deficiencies in Adult Patients with Chronic Airway Diseases.

Immunoglobulin G subclass deficiency (IgGSCD) is a relatively common primary immunodeficiency disease (PI) in adults. The biological significance of IgGSCD in patients with chronic airway diseases is controversial. We conducted a retrospective study to characterize the clinical features of IgGSCD in this population. This study examined the medical charts from 59 adult patients with IgGSCD who had bronchial asthma or chronic obstructive pulmonary disease (COPD) from January 2007 to December 2012. Subjects were classified according to the 10 warning signs developed by the Jeffrey Modell Foundation (JMF) and divided into two patient groups: group I (n = 17) met ≥ two JMF criteria, whereas group II (n = 42) met none. IgG3 deficiency was the most common subclass deficiency (88.1%), followed by IgG4 (15.3%). The most common infectious complication was pneumonia, followed by recurrent bronchitis, and rhinosinusitis. The numbers of infections, hospitalizations, and exacerbations of asthma or COPD per year were significantly higher in group I than in group II (P < 0.001, P = 0.012, and P < 0.001, respectively). The follow-up mean forced expiratory volume (FEV1) level in group I was significantly lower than it was at baseline despite treatment of asthma or COPD (P = 0.036). In conclusion, IgGSCD is an important PI in the subset of patients with chronic airway diseases who had recurrent upper and lower respiratory infections as they presented with exacerbation-prone phenotypes, decline in lung function, and subsequently poor prognosis.

Characteristics of Patients with Chronic Obstructive Pulmonary Disease at the First Visit to a Pulmonary Medical Center in Korea: The KOrea COpd Subgroup Study Team Cohort.

The Korea Chronic Obstructive Pulmonary Disorders Subgroup Study Team (Korea COPD Subgroup Study team, KOCOSS) is a multicenter observational study that includes 956 patients (mean age 69.9 ± 7.8 years) who were enrolled from 45 tertiary and university-affiliated hospitals from December 2011 to October 2014. The initial evaluation for all patients included pulmonary function tests (PFT), 6-minute walk distance (6MWD), COPD Assessment Test (CAT), modified Medical Research Council (mMRC) dyspnea scale, and the COPD-specific version of St. George's Respiratory Questionnaire (SGRQ-C). Here, we report the comparison of baseline characteristics between patients with early- (Global Initiative for Chronic Obstructive Lung Disease [GOLD] stage I and II/groups A and B) and late-stage COPD (GOLD stage III and IV/groups C and D). Among all patients, the mean post-bronchodilator FEV1 was 55.8% ± 16.7% of the predicted value, and most of the patients were in GOLD stage II (520, 56.9%) and group B (399, 42.0%). The number of exacerbations during one year prior to the first visit was significantly lower in patients with early COPD (0.4 vs. 0.9/0.1 vs. 1.2), as were the CAT score (13.9 vs. 18.3/13.5 vs. 18.1), mMRC (1.4 vs. 2.0/1.3 vs.1.9), and SGRQ-C total score (30.4 vs. 42.9/29.1 vs. 42.6) compared to late-stage COPD (all P < 0.001). Common comorbidities among all patients were hypertension (323, 37.7%), diabetes mellitus (139, 14.8%), and depression (207, 23.6%). The data from patients with early COPD will provide important information towards early detection, proper initial management, and design of future studies.

One-year prognosis and the role of brain natriuretic peptide levels in patients with chronic cor pulmonale.

Data on the clinical outcomes and role of brain natriuretic peptide (BNP) levels in patients with chronic cor pulmonale are limited. A total of 69 patients with chronic cor pulmonale, admitted for dyspnea (January 2007 to September 2011) to three university hospitals, were retrospectively reviewed. All of the patients had right ventricular (RV) dysfunction on echocardiography. The median age was 70.0 yr, and chronic obstructive pulmonary disease (40.6%) and tuberculosis-destroyed lung (TDL, 27.5%) were the leading causes of chronic cor pulmonale. At the 1-yr follow-up, the mortality rate was 15.9%, and the readmission rate was 53.7%; patients with TDL had higher mortality (31.6% vs. 10.0%; P=0.059) and readmission rates (78.9% vs. 43.8%; P=0.009) than those with non-TDL diseases. The area under the receiver operating characteristic curve for admission BNP levels to predict readmission was 0.788 (95% confidence interval [CI], 0.673-0.904), and the sensitivity and specificity of the cut-off value were 80.6% and 77.4%, respectively. In multivariate analysis, high admission BNP levels were a significant risk factor for subsequent readmission (hazard ratio, 1.049; 95% CI, 1.005-1.094). Additionally, admission BNP levels were well correlated with cardiac troponin I (r=0.558), and delta BNP also correlated with delta RV systolic pressure (n=25; r=0.562). In conclusion, among hospitalized patients with chronic cor pulmonale, admission high BNP levels are a significant risk factor for subsequent readmission. Therefore, more intensive monitoring and treatment are needed in patients with higher BNP levels.

Prevalence of Spirometrically-defined Restrictive Ventilatory Defect in Korea: The Fourth-2, 3, and Fifth Korean National Health and Nutrition Examination Survey, 2008-2012.

The aim of the study was to evaluate the prevalence of restrictive ventilatory defect and to determine the risk factors in subjects with spirometrically-defined restrictive ventilatory defect. We used the population-based, fourth-2, 3 (2008, 2009) and fifth (2010-2012) Korea National Health and Nutrition Examination Survey (KNHANES) to analyze 15,073 subjects, aged ≥40 yr who underwent spirometry. Chest radiographs were also analyzed to identify restrictive lung disease. Spirometrically-defined restrictive ventilatory defect (FEV1/FVC≥70% and FVC<80% of mean predicted value) was detected in 11.3% (n= 1,709) of subjects aged ≥40 yr. The prevalence increased to 12.3% on using the lower limit of normal (LLN) criteria. Approximately 99.4% of subjects were classified as mild restrictive. Among these, 11.3% had inactive tuberculosis (TB) lesion, 2.2% cardiac disease, 2.0% previous operation scar or radiation injury and/or mediastinal disease, and 7.4% other pulmonary disease suggestive of restrictive lung diseases on chest radiograph. Evidence of previous TB history was independently associated with restrictive ventilatory defect (odds ratios [OR], 1.78; 95% confidence interval, 1.45-2.18) after adjustment for gender, age, smoking, area for residence and body mass index. The prevalence of restrictive ventilatory defect among the nationwide population in Korea was 11.3% with fixed ratio criterion and 12.3% with LLN criterion. Most cases were of the mild restrictive category and previous TB history is the independent risk factor for restrictive ventilatory defect.

Asthma and severity of the 2009 novel H1N1 influenza: a case-control study.

OBJECTIVE: Previous studies reported that the most common chronic condition found among hospitalized patients due to the novel 2009 H1N1 influenza was asthma. However, these studies did not include a concurrent control group. Thus, we investigated the association of asthma status and severity of H1N1 influenza in adults. METHODS: The study was designed as a multi-site case-control study. Cases were patients who had positive PCR for H1N1 influenza and were admitted to the ICU or general ward with a diagnosis of H1N1 influenza from 1 January 2009 to 31 December 2009. Controls were patients who had positive PCR for H1N1 influenza, but were not admitted to hospitals. RESULTS: There were 91 H1N1 cases admitted to either ICU (n = 41) or general hospital ward (n = 50), and 56 controls who met the matching criteria were available. Of the 91 cases, the mean age was 47.3 years, 59% were female, and 38% had comorbid conditions. Of the 91 cases, 12 (13%) had asthma. Stratified analysis by comorbid conditions showed that among those without any comorbid conditions, 8 of 56 cases (14%) and 2 of 49 controls (4%) had asthma, (OR: 3.92, 95% CI: 0.79-19.42, p = 0.095) whereas, among the 39 subjects with one or more comorbid conditions, one of 7 controls (14%) had asthma and 4 of 35 (11%) cases had asthma (p = 0.83). CONCLUSIONS: Asthma may be associated with severity of H1N1 influenza among those without any non-asthma comorbid conditions. However, the limited sample size did not allow this study to fully establish statistical significance. We still recommend asthmatics as a priority group for influenza vaccination and treatment.