Factors Associated with the Discrepancy between Exercise Capacity and Airflow Limitation in Patients with Chronic Obstructive Pulmonary Disease.

BACKGROUND: Exercise capacity is associated with lung function decline in chronic obstructive pulmonary disease (COPD) patients, but a discrepancy between exercise capacity and airflow limitation exists. This study aimed to explore factors contributing to this discrepancy in COPD patients. METHODS: Data for this prospective study were obtained from the Korean COPD Subgroup Study. The exercise capacity and airflow limitation were assessed using the 6-minute walk distance (6-MWD; m) and forced expiratory volume in 1 second (FEV1). Participants were divided into four groups: FEV1 >50%+6-MWD >350, FEV1 >50%+6- MWD ≤350, FEV1 ≤50%+6-MWD >350, and FEV1 ≤50%+6-MWD ≤350 and their clinical characteristics were compared. RESULTS: A total of 883 patients (male:female, 822:61; mean age, 68.3±7.97 years) were enrolled. Among 591 patients with FEV1 >50%, 242 were in the 6-MWD ≤350 group, and among 292 patients with FEV1 ≤50%, 185 were in the 6-MWD >350 group. The multiple regression analyses revealed that male sex (odds ratio [OR], 8.779; 95% confidence interval [CI], 1.539 to 50.087; p=0.014), current smoking status (OR, 0.355; 95% CI, 0.178 to 0.709; p=0.003), and hemoglobin levels (OR, 1.332; 95% CI, 1.077 to 1.648; p=0.008) were significantly associated with discrepancies in exercise capacity and airflow limitation in patients with FEV1 >50%. Meanwhile, in patients with FEV1 ≤50%, diffusion capacity of carbon monoxide (OR, 0.945; 95% CI, 0.912 to 0.979; p=0.002) was significantly associated with discrepancies between exercise capacity and airflow limitation. CONCLUSION: The exercise capacity of COPD patients may be influenced by factors other than airflow limitation, so these aspects should be considered when assessing and treating patients.

Impact of coexistent preserved ratio impaired spirometry on the survival of patients with lung cancer: Analysis of data from the Korean Association for Lung Cancer Registry.

BACKGROUND: Preserved ratio impaired spirometry (PRISm) is a common spirometric pattern that is associated with respiratory symptoms and higher mortality rates. However, the relationship between lung cancer and PRISm remains unclear. This study investigated the clinical characteristics of lung cancer patients with PRISm and the potential role of PRISm as a prognostic factor. METHODS: We retrospectively reviewed data collected from 2014 to 2015 in the Korean Association for Lung Cancer Registry. We classified all patients into three subgroups according to lung function as follows: normal lung function; PRISm (forced expiratory volume in 1 s [FEV1 ] < 80% predicted and FEV1 /forced vital capacity [FVC] ≥ 0.7); and chronic obstructive pulmonary disease (COPD; FEV1/FVC < 0.7). In non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC), the overall survival period was compared among the three subgroups. The prognostic factors were investigated using Cox regression analysis. RESULTS: Of the 3763 patients, 38.6%, 40.1%, and 21.3% had normal lung function, COPD, and PRISm, respectively. Patients with PRISm had poorer overall survival than those with COPD or normal lung function in NSCLC and SCLC (Mantel-Cox log-rank test, p < 0.05). In the risk-adjusted analysis, overall survival was independently associated with COPD (hazard ratio [HR] 1.209, p = 0.027) and PRISm (HR 1.628, p < 0.001) in NSCLC, but was only associated with PRISm (HR 1.629, p = 0.004) in SCLC. CONCLUSIONS: PRISm is a significant pattern of lung function in patients with lung cancer. At the time of lung cancer diagnosis, pre-existing PRISm should be considered a predictive factor of poor prognosis.

Serum hepatocyte growth factor as a predictor of disease severity and future exacerbations in patients with non-cystic fibrosis bronchiectasis.

BACKGROUND: Serum biomarkers associated with the severity of non-cystic fibrosis (CF) bronchiectasis are insufficient. This study determined the association of serum hepatocyte growth factor (HGF), osteopontin, and pentraxin-3 levels with disease severity and exacerbation in patients with non-CF bronchiectasis. METHODS: Serum levels of HGF, osteopontin, and pentraxin-3 were measured in patients with clinically stable non-CF bronchiectasis (n = 61). The correlation between the biomarkers and bronchiectasis severity index (BSI) and FACED score was assessed using univariate and multivariate linear regression analyses. Predictive variables associated with exacerbation were analyzed using a Cox proportional hazards model and the time to first exacerbation in high and low HGF groups during the observation period was compared using Kaplan-Meier survival curves. RESULTS: The BSI showed significant correlation with HGF (r = 0.423; p = 0.001) and pentraxin-3 (r = 0.316; p = 0.013). The FACED score was significantly correlated with HGF (r = 0.406; p = 0.001). Univariate and multivariate linear regression analysis revealed that serum level of HGF was independently associated with both scoring systems. The high HGF group showed a significantly shorter time to first exacerbation (Log-rank test, p = 0.014). Multivariate Cox proportional hazards regression analysis revealed that high serum HGF level and colonization with non-pseudomonas organisms were independent predictors of future exacerbations (HR 2.364; p = 0.024 and HR 2.438; p = 0.020, respectively). CONCLUSION: Serum level of HGF is a potential biomarker that is closely associated with disease severity and future risk of exacerbations in patients with non-CF bronchiectasis.

Serum albumin is a predictor of respiratory hospitalization in patients with bronchiectasis.

We evaluated serum albumin as an index for predicting respiratory hospitalization in patients with bronchiectasis. We retrospectively reviewed the medical records of 177 patients with bronchiectasis, categorized them into low and normal albumin groups, and compared their clinical characteristics. The prediction of respiratory hospitalization by factors such as serum albumin level, bronchiectasis severity index (BSI), and FACED score (an acronym derived from five variables of forced expiratory volume in 1 s; FEV1, age, chronic colonization of Pseudomonas aeruginosa, extent of bronchiectasis, and dyspnea) was assessed. There were 15 and 162 patients categorized in the low and normal albumin groups, respectively. The low albumin group had lower body mass index and forced expiratory volume in 1 s, and higher age, frequency of previous respiratory hospitalization, percentage of Pseudomonas colonization, number of affected lobes, BSI and FACED scores, and C-reactive protein (CRP) level, than the normal albumin group. The areas under the receiver operating characteristic curve of serum albumin level and BSI and FACED scores for predicting respiratory hospitalization were 0.732 (95% confidence interval (CI), 0.647-0.816), 0.873 (95% CI, 0.817-0.928), and 0.708 (95% CI, 0.618-0.799), respectively. Albumin level, CRP, modified Medical Research Council score, and chronic Pseudomonas aeruginosa (and other organisms) colonization were independent risk factors for respiratory hospitalization. Low serum albumin level was associated with worse clinical condition, higher severity scores, and respiratory hospitalization in patients with bronchiectasis.

Chronic cough is associated with depressive mood in women regardless of smoking status and lung function.

BACKGROUND: Chronic cough is a common respiratory symptom, and, if persistent, the patient's quality of life can worsen and result in a depressive mood, or vice versa. Although previous reports suggest a relationship between chronic cough and depression, we further investigated this relationship according to smoking status and lung function. METHODS: This observational study used cross-sectional data from the 6th Korean National Health and Nutrition Examination Survey (2014 and 2016). Propensity score matching using age, sex, smoking status, and lung function was performed for participants with and without chronic cough to reduce the confounding effects associated with depressive mood. Questionnaires recorded coughs persisting for >3 months and the Patient Health Questionnaire-9 (PHQ-9) assessed the severity of depressive mood. RESULTS: Among 12 494 participants who were >18 years old, 226 with chronic cough were matched with 226 with non-chronic cough. Overall, chronic cough participants showed higher PHQ-9 scores than the non-chronic cough participants (4.29 ± 5.23 vs. 2.63 ± 3.38, P < .001). When stratified by sex, the difference remained significant in women (5.69 ± 5.96 vs. 3.05 ± 3.97, P < .001) but not in men (3.18 ± 4.27 vs. 2.31 ± 3.65, P = .092). When stratified by lung function status, the difference remained significant for those with normal lung function (4.32 ± 5.32 vs. 2.78 ± 3.86, P = .003) and reduced lung function (4.19 ± 4.93 vs. 2.11 ± 3.55, P ≤ 0.001). Multivariate logistic regression analysis revealed that chronic cough was associated with PHQ-9 score (odds ratio [OR], 1.06; 95% confidence interval [CI], 1.014-1.27, P = .014), chronic obstructive pulmonary disease (OR, 4.87; 95% CI, 1.041-22.86, P = .044) and physician-diagnosed bronchial asthma (OR, 2.93; 95% CI, 1.162-7.435, P = .023). CONCLUSIONS: Depressive mood is significantly correlated with chronic cough in females.