Publications (6)7.52 Total impact
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Article: Exertional Desaturation as a Predictor of Rapid Lung Function Decline in COPD.
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ABSTRACT: Background: To date, no clinical parameter has been associated with the decline in lung function other than emphysema severity in COPD. Objectives: The main purpose of this study was to explore whether the rate of lung function decline differs between COPD patients with and without exertional desaturation. Methods: A total of 224 subjects were selected from the Korean Obstructive Lung Disease cohort. Exertional desaturation was assessed using the 6-min walk test (6MWT), and defined as a post-exercise oxygen saturation (SpO(2)) of <90% or a ≥4% decrease. The cohort was divided into desaturator (n = 47) and non-desaturator (n = 177) groups. Results: There was a significant difference between the desaturator and non-desaturator groups in terms of the change in pre-bronchodilator forced expiratory volume in 1 s (FEV(1)) over a 3-year period of follow-up (p = 0.006). The mean rate of decline in FEV(1) was greater in the desaturator group (33.8 ml/year) than in the non-desaturator group (11.6 ml/year). A statistically significant difference was also observed between the two groups in terms of the change in the St. George's Respiratory Questionnaire (SGRQ) total score over 3 years (p = 0.001). Conclusions: This study suggests, for the first time, that exertional desaturation may be a predictor of rapid decline in lung function in patients with COPD. The 6MWT may be a useful test to predict a rapid lung function decline in COPD.Respiration 12/2012; · 2.26 Impact Factor -
Article: Validity and Reliability of CAT and Dyspnea-12 in Bronchiectasis and Tuberculous Destroyed Lung.
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ABSTRACT: The objective of this study was to assess the validity and reliability of the Korean version of chronic obstructive pulmonary disease assessment test (CAT) and Dyspnea-12 Questionnaire for patients with bronchiectasis or tuberculous destroyed lung. For 62 bronchiectasis patients and 37 tuberculous destroyed lung patients, 3 questionnaires including St. George's Respiratory Questionnaires (SGRQ), CAT, and Dyspnea-12 were obtained, in addition to spirometric measurements. To assess the validity of CAT and Dyspnea-12, correlation with SGRQ was evaluated. To assess the reliability of CAT and Dyspnea-12, Cronbach's α coefficient was calculated. The mean ages of the patients were 60.7±8.3 years in bronchiectasis and 64.4±9.3 years in tuberculous destroyed lung. 46.8% and 54.1% were male, respectively. The SGRQ score was correlated with the score of the Korean version of CAT (r=0.72, p<0.0001) and Dyspnea-12 (r=0.67, p<0.0001) in bronchiectasis patients. The SGRQ score was correlated with the score of CAT (r=0.86, p<0.0001) and Dyspnea-12 (r=0.80, p<0.0001) in tuberculous destroyed lung patients. The Cronbach's α coefficient for the CAT and Dyspnea-12 were 0.84 and 0.90 in bronchiectasis, and 0.88 and 0.94 in tuberculous destroyed lung, respectively. We found that Korean version of CAT and Dyspnea-12 are valid and reliable in patients with tuberculous destroyed lung and bronchiectasis.Tuberculosis and respiratory diseases. 06/2012; 72(6):467-74. -
Article: Response patterns to bronchodilator and quantitative computed tomography in chronic obstructive pulmonary disease.
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ABSTRACT: Patients with chronic obstructive pulmonary disease (COPD) show different spirometric response patterns to bronchodilator, such that some patients show improvement principally in expiratory flow (forced expiratory volume in 1 s; FEV(1)), whereas others respond by improvement of lung volume (forced vital capacity; FVC). The mechanisms of these different response patterns to bronchodilator remain unclear. We investigated the associations between bronchodilator responsiveness and quantitative computed tomography (CT) indices in patients with COPD. Data on a total of 101 patients with stable COPD were retrospectively analysed. Volume and flow responses to bronchodilator were assessed by FVC and FEV(1) changes before and after inhalation of salbutamol (400 μg). Volumetric CT was performed to quantify emphysema, air trapping and large airway thickness. Emphysema was assessed by the volume fraction of the lung under -950 Hounsfield units (HU; V(950)) at full inspiration and air trapping by the ratio of mean lung density (MLD) at full expiration and inspiration. Airway wall thickness and wall area percentage (WA%; defined as wall area/[wall area + lumen area] × 100), were measured near the origin of right apical and left apico-posterior bronchus. Among quantitative CT indices, the CT emphysema index (V(950 insp)) showed a significant negative correlation with postbronchodilator FEV(1) change (R = -0·213, P = 0·004), and the CT air-trapping index correlated positively with postbronchodilator FVC change(R = 0·286, P≤0·001). Multiple linear regression analysis showed that CT emphysema index had independent association with postbronchodilator FEV(1) change and CT air-trapping index with postbronchodilator FVC change. The degrees of emphysema and air trapping may contribute to the different response patterns to bronchodilator in patients with COPD.Clinical Physiology and Functional Imaging 01/2012; 32(1):12-8. · 1.33 Impact Factor -
Article: Comparison of clinico-physiologic and CT imaging risk factors for COPD exacerbation.
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ABSTRACT: To date, clinico-physiologic indices have not been compared with quantitative CT imaging indices in determining the risk of chronic obstructive pulmonary disease (COPD) exacerbation. We therefore compared clinico-physiologic and CT imaging indices as risk factors for COPD exacerbation in patients with COPD. We retrospectively analyzed 260 COPD patients from pulmonary clinics at 11 hospitals in Korea from June 2005 to November 2009 and followed-up for at least one year. At the time of enrollment, none of these patients had COPD exacerbations for at least 2 months. All underwent clinico-physiologic and radiological evaluation for risk factors of COPD exacerbation. After 1 yr, 106 of the 260 patients had at least one exacerbation of COPD. Multiple logistic regression analysis showed that old age, high Charlson Index, and low FEV(1) were significant in a clinico-physiologic model, with C-statistics of 0.69, and that increased age and emphysema index were significant in a radiologic model, with C-statistics of 0.64. The difference between the two models was statistically significant (P = 0.04 by bootstrap analysis). Combinations of clinico-physiologic risk factors may be better than those of imaging risk factors in predicting COPD exacerbation.Journal of Korean medical science 12/2011; 26(12):1606-12. · 0.84 Impact Factor -
Article: Predictors of pulmonary function response to treatment with salmeterol/fluticasone in patients with chronic obstructive pulmonary disease.
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ABSTRACT: Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease and responses to therapies are highly variable. The aim of this study was to identify the predictors of pulmonary function response to 3 months of treatment with salmeterol/fluticasone in patients with COPD. A total of 127 patients with stable COPD from the Korean Obstructive Lung Disease (KOLD) Cohort, which were prospectively recruited from June 2005 to September 2009, were analyzed retrospectively. The prediction models for the FEV(1), FVC and IC/TLC changes after 3 months of treatment with salmeterol/fluticasone were constructed by using multiple, stepwise, linear regression analysis. The prediction model for the FEV(1) change after 3 months of treatment included wheezing history, pre-bronchodilator FEV(1), post-bronchodilator FEV(1) change and emphysema extent on CT (R = 0.578). The prediction models for the FVC change after 3 months of treatment included pre-bronchodilator FVC, post-bronchodilator FVC change (R = 0.533), and those of IC/ TLC change after 3 months of treatment did pre-bronchodilator IC/TLC and post-bronchodilator FEV(1) change (R = 0.401). Wheezing history, pre-bronchodilator pulmonary function, bronchodilator responsiveness, and emphysema extent may be used for predicting the pulmonary function response to 3 months of treatment with salmeterol/fluticasone in patients with COPD.Journal of Korean medical science 03/2011; 26(3):379-85. · 0.84 Impact Factor -
Article: Validation of the lower limit of normal diffusing capacity for detecting emphysema.
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ABSTRACT: Diffusing capacity for carbon monoxide (D(Lco)) has been regarded as reliable for detecting emphysema. The lower 5th percentile of the reference population has been used as the lower limit of normal (LLN) for D(Lco), without clinical validation. We performed this study to validate the LLN for D(Lco) and to determine the optimum cutoff LLN value for detecting emphysema. A total of 197 COPD patients and 103 healthy adult subjects were included. COPD patients with emphysema were defined as COPD patients in whom volumetric CT showed that the volume fraction of the lung at less than -950 Hounsfield units at full inspiration was more than 15%. All other COPD patients were defined as COPD patients without emphysema. All measured D(Lco) values were transformed to estimates of reference population percentiles. ROC curve analysis was used to validate and to determine the optimum cutoff percentile value as the LLN for D(Lco). Of the 197 COPD patients, 126 were classified as having emphysema and 71 as without emphysema. On ROC curve analysis, the lower 5th percentile used as the LLN for D(Lco) had a sensitivity of 68.3% and a specificity of 98.1% to differentiate COPD patients with emphysema from healthy subjects. The lower 9th percentile was the best LLN cutoff value for detecting COPD patients with emphysema. The lower 5th percentile of the reference population may not be the best LLN cutoff value for D(Lco) for detecting emphysema.Respiration 01/2011; 81(4):287-93. · 2.26 Impact Factor
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2011–2012
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Ulsan University Hospital
Ulsan, Ulsan, South Korea
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