PURPOSE: In clinical practice, some patients with asthma show incompletely reversible airflow obstruction, resembling chronic obstructive pulmonary disease (COPD). The aim of this study was to analyze this overlap phenotype of asthma with COPD feature. MATERIALS AND METHODS: A total of 256 patients, over the age of 40 years or more with a diagnosis of asthma, based on either 1) positive response to bronchodilator: >200 mL forced expiratory volume in 1 s (FEV1) and >12% baseline or 2) positive methacholine or mannitol provocation test, were enrolled. Among the asthma patients, we defined the overlap group with incompletely reversible airflow obstruction [postbronchodilator FEV1/forced vital capacity (FVC) <70] at the initial time of admission and continuing airflow obstruction after at least 3 months follow up. We evaluated clinical features, serum eosinophil counts, serum total immunoglobulin (Ig) E with allergy skin prick test, spirometry, methacholine or mannitol provocation challenges and bronchodilator responses, based on their retrospective medical record data. All of the tests mentioned above were performed within one week. RESULTS: The study population was divided into two groups: asthma only (62%, n=159, postbronchodilator FEV1/FVC > or =70) and overlap group (38%, n=97, postbronchodilator FEV1/FVC <70). The overlap group was older, and contained more males and a higher percentage of current or ex-smokers than the asthma only group. Significantly lower FEV1 and higher total lung capacity, functional residual capacity, and residual volume were observed in the overlap group. Finally, significantly lower serum eosinophil count and higher IgE were seen in the overlap group. CONCLUSION: Our results showed that the overlap phenotype was older, male asthmatic patients who have a higher lifetime smoking intensity, more atopy and generally worse lung function.
Adult ; Age Factors ; Aged ; Asthma/epidemiology/*physiopathology ; Female ; Forced Expiratory Volume/physiology ; Humans ; Male ; Middle Aged ; Pulmonary Disease, Chronic Obstructive/epidemiology/*physiopathology ; Retrospective Studies ; Sex Factors

Chronic sputum is a troublesome symptom in many respiratory diseases. The prevalence of chronic sputum varies from 1.2% to 13% according to the country. The purpose of this study was to estimate the prevalence of chronic sputum and to find its associated factors in a general Korean population. We analyzed the data of the Korea National Health and Nutrition Examination Survey 2010 and 2011. A total number of 6,783 subjects aged 40 yr or more were enrolled in this study with 3,002 men and 3,781 women. As a result, the prevalence of chronic sputum was 6.3% (n=430). Significant risk factors for chronic sputum by multivariate analysis were: age (> or =70 yr) (odds ratio [OR], 1.954; 95% confidence interval [CI], 1.308-2.917), current smoking (OR, 4.496; 95% CI, 3.001-6.734), chronic obstructive pulmonary disease (COPD) (OR, 1.483; 95% CI, 1.090-2.018), and tuberculosis (OR, 1.959; 95% CI, 1.307-2.938). In conclusion, the prevalence of chronic sputum in Korea was in the intermediate range compared with other countries. Smoking is a preventable risk factor identified in this study, and major respiratory diseases, such as COPD and tuberculosis, should be considered in subjects with chronic sputum.
Adult ; Aged ; Chronic Disease ; Demography ; Female ; Humans ; Logistic Models ; Lung/physiopathology ; Male ; Middle Aged ; Odds Ratio ; Prevalence ; Pulmonary Disease, Chronic Obstructive/*epidemiology/physiopathology ; Questionnaires ; Republic of Korea ; Risk Factors ; Smoking ; *Sputum/microbiology ; Tuberculosis/*epidemiology/physiopathology

Adult ; Aged ; Aged, 80 and over ; China ; epidemiology ; Female ; Humans ; Male ; Middle Aged ; Pulmonary Disease, Chronic Obstructive ; epidemiology ; physiopathology ; Risk Factors ; Smoking ; Surveys and Questionnaires

Objective: To understand the performance of spirometry examination in adults aged ≥40 years and provide evidence for the improvement of comprehensive prevention and control of COPD and the evaluation on the effects of current prevention and control measures. Methods: The study subjects were those included in national COPD surveillance in China during 2014-2015. The surveillance used a multi-stage, stratified cluster sampling strategy and a total of 125 surveillance points in 31 provinces were covered. A total of 75 107 adults aged ≥40 years received a questionnaire survey in face to face interviews to collect the information about their acceptance of spirometry examination in previous years. The estimated rate (95%CI) of spirometry examination was calculated based on complex sampling weight design. Results: A total of 74 591 subjects were included in the analyses. The estimated rate of spirometry examination was 4.5% (95%CI: 3.7%-5.2%), and it was significantly higher in men than in women (P<0.001), in urban population than in rural population (P<0.001). The rate of spirometry examination increased with the increase of education level (P<0.001). The rate of spirometry examination was highest in retirees (10.8%, 95%CI: 8.2%-13.3%), and lowest in those working in the industry of agriculture, forestry, animal husbandry, fishery and water conservancy (2.4%, 95%CI: 2.0%-2.9%). The rate of spirometry examination was high in those with previous chronic respiratory diseases and respiratory symptoms, i.e. 13.4% (95%CI: 10.5%-16.4%) and 15.0% (95%CI: 10.5%-19.4%) respectively. The rate of spirometry examination in former smokers was 7.4% (95%CI: 6.0%-8.8%), slightly higher than those in current smokers and never smokers, 4.7% (95%CI: 3.9%-5.5%) and 3.9% (95%CI: 3.0%-4.7%), respectively. In different population groups, the rate of spirometry examination was lowest in rural population who had received no formal education (1.8%, 95%CI: 1.2%-2.3%) and highest in urban population with respiratory symptoms (20.2%, 95%CI: 12.6%-27.8%). Conclusion: The rate of spirometry examination is extremely low in adults aged ≥40 years in China, therefore effective measures should be taken to increase the rate of spirometry examination in adults in China.
Adult ; China/epidemiology* ; Cross-Sectional Studies ; Female ; Humans ; Male ; Prevalence ; Pulmonary Disease, Chronic Obstructive/physiopathology* ; Rural Population ; Spirometry ; Surveys and Questionnaires ; Urban Population

BACKGROUND/AIMS: Smoking is widely acknowledged as the single most important risk factor for chronic obstructive pulmonary disease (COPD). However, the risk of COPD in nonsmokers exposed to secondhand smoke remains controversial. In this study, we investigated the association of secondhand smoke exposure with COPD prevalence in nonsmokers who reported never smoking. METHODS: This study was based on data obtained from the Korean National Health and Nutrition Examination Surveys (KNHANES) conducted from 2008 to 2010. Using nationwide stratified random sampling, 8,596 participants aged > or = 40 years of age with available spirometry results were recruited. After selecting participants who never smoked, the duration of exposure to secondhand smoke was assessed based on the KNHANES questionnaire. RESULTS: The prevalence of COPD was 6.67% in participants who never smoked. We divided the participants who had never smoked into those with or without exposure to secondhand smoke. The group exposed to secondhand smoke was younger with less history of asthma and tuberculosis, higher income, and higher educational status. Multivariate logistic regression analysis determined that secondhand smoke did not increase the prevalence of COPD. CONCLUSIONS: There was no significant difference in the prevalence of COPD between participants who had never smoked with or without exposure to secondhand smoke in our study. Thus, secondhand smoke may not be an important risk factor for the development of COPD in patients who have never smoked.
Adult ; Aged ; Cotinine/urine ; Female ; Humans ; Male ; Middle Aged ; Nutrition Surveys ; Prevalence ; Pulmonary Disease, Chronic Obstructive/epidemiology/*etiology/physiopathology ; Republic of Korea/epidemiology ; Respiratory Function Tests ; Risk Factors ; Tobacco Smoke Pollution/*adverse effects

BACKGROUND/AIMS: Legal pulmonary disability in Korea is decided for chronic respiratory patients who have been diagnosed for a year or more, and the patients haven't gotten better after more than 2 months of sufficient treatment and they have shown no change in their pulmonary function within the two years after their original diagnosis. The purpose of this study was to investigate the clinical features and progress of those patients who have been diagnosed as having pulmonary disability. METHODS: We reviewed retrospectively the medical records of the patients who had been decided as having pulmonary disability at a tertiary university hospital from 2003 to 2004, and these patients could be followed up for more than 6 months. RESULTS: The number of enrolled patients was 118 (male : female = 95 : 23) and their mean age was 60+/-10 years. Their major underlying diseases were chronic obstructive pulmonary disease (n=45, 38%), tuberculous destroyed lung (n=29, 25%), and bronchial asthma (n=27, 23%). Of them, the number of patients with a class 1 pulmonary disability were 24 (20%), there were 28 class 2 patients (24%) and 66 class 3 patients (56%). The FEV1 could be followed up for 42 of these patients, of whom 20 patients showed no change or a decrease in their FEV1 but 22 showed an increased FEV1. Especially, some of them showed the increase of their FEV1 of 10% or more, and the 50% of them were patients with bronchial asthma. During the follow-up period, 6 patients died; 3 were class 1, 1 was class 2 and 2 were class 3. Five of these patients died of their underlying pulmonary diseases or combined pneumonia. CONCLUSIONS: It is necessary to decide the pulmonary disability after sufficient treatment and to perform periodic follow-up testing even after the disability decision for confirming that the disability is stable and also to adjust the class of the disability. Further studies are needed to observe the clinical progress and prognosis of patients with pulmonary disability by performing long-term follow-up for a large number of patients.
Asthma/mortality/*physiopathology ; Blood Gas Monitoring, Transcutaneous ; Decision Making ; *Disabled Persons ; Female ; Follow-Up Studies ; Forced Expiratory Volume ; Health Status Indicators ; Hospitals, University/statistics & numerical data ; Humans ; Korea/epidemiology ; Male ; Middle Aged ; Pulmonary Disease, Chronic Obstructive/mortality/*physiopathology ; Retrospective Studies ; Severity of Illness Index ; Time Factors ; Tuberculosis, Pulmonary/mortality/*physiopathology

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.
Aged ; Cohort Studies ; Comorbidity ; Depression/epidemiology ; Diabetes Mellitus/epidemiology ; Dyspnea/complications ; Female ; Forced Expiratory Volume ; Hospitals, University ; Humans ; Hypertension/epidemiology ; Lung/physiopathology ; Male ; Middle Aged ; Pulmonary Disease, Chronic Obstructive/complications/*diagnosis/physiopathology ; Quality of Life ; Republic of Korea ; Respiratory Function Tests ; Severity of Illness Index ; Societies, Medical ; Surveys and Questionnaires ; Tertiary Care Centers ; Walk Test