Background: Muscle wasting and chronic inflammation are predominant features of patients with COPD. Systemic inflammation is associated with an accelerated decline in lung function. In this study, the prevalence of sarcopenia and the relationships between sarcopenia and systemic inflammations in patients with stable COPD were investigated. Materials and methods: In a cross-sectional design, muscle strength and muscle mass were measured by handgrip strength (HGS) and bioelectrical impedance analysis in 80 patients with stable COPD. Patients (≥40 years old) diagnosed with COPD were recruited from outpatient clinics, and then COPD stages were classified. Sarcopenia was defined as the presence of both low muscle strength (by HGS) and low muscle mass (skeletal muscle mass index [SMMI]). Levels of circulating inflammatory biomarkers (IL-6 and high-sensitivity TNFα [hsTNFα]) were measured. Results: Sarcopenia was prevalent in 20 (25%) patients. Patients with sarcopenia were older, had lower body mass index, and a higher percentage of cardiovascular diseases. In addition, they had significantly higher modified Medical Research Council scores and lower 6-minute walk distance than those without sarcopenia. HGS was significantly correlated with age, modified Medical Research Council score, and COPD Assessment Test scores. Both HGS and SMMI had associations with IL-6 and hsTNFα (HGS, r=-0.35, P=0.002; SMMI, r=-0.246, P=0.044) level. In multivariate analysis, old age, lower body mass index, presence of cardiovascular comorbidities, and higher hsTNFα levels were significant determinants for sarcopenia in patients with stable COPD. Conclusion: Sarcopenia is very common in patients with stable COPD, and is associated with more severe dyspnea-scale scores and lower exercise tolerance. Systemic inflammation could be an important contributor to sarcopenia in the stable COPD population.

Background: Coronavirus disease 2019 (COVID-19) has spread worldwide rapidly. However, the effects of asthma, asthma medication and asthma severity on the clinical outcomes of COVID-19 have not yet been established. Methods: The study included 7590 de-identified patients, who were confirmed to have COVID-19 using the severe acute respiratory syndrome coronavirus 2 RNA-PCR tests conducted up to May 15, 2020; we used the linked-medical claims data provided by the Health Insurance Review and Assessment Service. Asthma and asthma severity (steps suggested by the Global Initiative for Asthma) were defined using the diagnostic code and history of asthma medication usage. Results: Among 7590 COVID-19 patients, 218 (2.9%) had underlying asthma. The total medical cost associated with COVID-19 patients with underlying asthma was significantly higher than that of other patients. Mortality rate for COVID-19 patients with underlying asthma (7.8%) was significantly higher than that of other patients (2.8%; p<0.001). However, asthma was not an independent risk factor for the clinical outcomes of COVID-19 after adjustment, nor did asthma medication use and asthma severity affect the clinical outcomes of COVID-19. However, use of oral short-acting β ₂ -agonists was an independent factor to increase the total medical cost burden. Patients with step 5 asthma showed significant prolonged duration of admission compared to those with step 1 asthma in both univariate and multivariate analysis. Conclusions: Asthma led to poor outcomes of COVID-19; however, underlying asthma, use of asthma medication and asthma severity were not independent factors for poor clinical outcomes of COVID-19, generally.

Purpose: The forced mid-expiratory flow (FEF_25-75%) value is a potentially sensitive marker of obstructive peripheral airflow. We aimed to assess whether FEF_25-75% can be an early predictor of chronic obstructive pulmonary disease (COPD). Patients and Methods: Between July 1, 2007 and June 31, 2009, we identified 3624 patients who underwent a pulmonary function test (PFT) in Gangnam Severance Hospital. We selected 307 patients aged over 40 years without COPD who had normal PFT results at baseline and who had follow-up PFT records more than 1 year later. A FEF_25-75% z-score less than − 0.8435 was considered low. We defined COPD as a forced expiratory volume in one second/forced vital capacity value of less than 0.7 before July 31, 2019. Results: Among 307 patients, 91 (29.6%) had low FEF_25-75% at baseline. After 10 years, the incidence rate of COPD in the low FEF_25-75% group was significantly higher than that in the normal FEF_25-75% group (41.8% vs 7.4%; P-value< 0.001). The Cox proportional hazard model showed that age (hazard ratio [HR] 1.09; P-value< 0.001), smoking status (occasional smoker HR, 4.59; P-value< 0.001 and long-term smoker HR, 2.18; P-value=0.023), and low FEF_25-75% (HR, 3.31; P-value< 0.001) were predictive factors for the development of COPD. Conclusion: The FEF_25-75% value in patients with normal lung function is a useful predictor for the development of COPD. We should carefully monitor patients who present with low FEF_25-75% values, even if they have normal lung function.

The aim of this study was to confirm the synergistic effect of colistin/rifampicin combination therapy compared with colistin monotherapy in pneumonia caused by colistin-resistant Acinetobacter baumannii (CoRAB). The utility of the Etest was also assessed. Nine subjects with pneumonia caused by CoRAB were enrolled from 20 July 2016 to 21 June 2018. Subjects were randomised to colistin/rifampicin combination therapy or colistin monotherapy. After exclusion of one patient who dropped out, the microbiological response (MR) and clinical response (CR) on Day 14 and mortality on Day 30 were assessed. Etest was conducted using CoRAB isolated at study enrolment. The MR rate in the colistin/rifampicin combination group (100.0%) was better than that in the colistin group (40.0%), however the difference was not statistically significant (P=0.196). The CR rate was not significantly different between the two groups. The MR (100.0%) and CR (100.0%) rates in subjects with 'partial synergy' as shown by Etest were higher than those (25.0% and 50.0%, respectively) in subjects with 'indifferent' results (i.e. no synergistic effect), however the difference was not statistically significant (P=0.143 and 0.429, respectively). Mortality occurred in two subjects with 'indifferent' results by Etest. Colistin/rifampicin combination therapy may have potential to achieve MR in pneumonia caused by CoRAB; however, achieving CR with this treatment is doubtful. 'Partial synergy' of colistin and rifampicin, as shown by Etest, may be a good prognostic factor [ClinicalTrial.gov ID: NCT03622918].

Preserved ratio impaired spirometry (PRISm) is an incompletely understood respiratory condition. We investigated the incidence and significant predictive factors of chronic obstructive pulmonary disease (COPD) in PRISm patients. From 11,922 subjects registered in the Korea National Health and Nutrition Examination Survey, never or light smokers, young subjects, and those already medically diagnosed with COPD (defined by ICD-10 code and prescribed medication) were excluded. The 2666 remaining subjects were categorized into PRISm (normal forced expiratory volume in the first second [FEV1]/force vital capacity [FVC] [≥ 0.7] and low FEV1 (< 80%); n = 313); normal (n = 1666); and unrevealed COPD groups (FEV1/FVC ratio < 0.7; n = 687). These groups were compared using matched Health Insurance Review and Assessment Service data over a 3-year follow-up. COPD incidence in PRISm patients (17/1000 person-year [PY]) was higher than that in normal subjects (4.3/1000 PY; P < 0.001), but lower than that in unrevealed COPD patients (45/1000 PY; P < 0.001). PRISm patients visited hospitals, took COPD medication, and incurred hospitalization costs more frequently than normal subjects, but less frequently than unrevealed COPD patients. In the overall sample, age, FVC, FEV1, dyspnea, and wheezing were significant predictors of COPD, but in PRISm patients, only age (OR, 1.14; P = 0.002) and wheezing (OR, 4.56; P = 0.04) were significant predictors. PRISm patients are likely to develop COPD, and should be monitored carefully, especially older patients and those with wheezing, regardless of lung function.

Background We aimed to identify clinicopathologic characteristics and risk of invasiveness of lung adenocarcinoma in surgically resected pure ground-glass opacity lung nodules (GGNs) smaller than 2 cm. Methods Among 755 operations for lung cancer or tumors suspicious for lung cancer performed from 2012 to 2016, we retrospectively analyzed 44 surgically resected pure GGNs smaller than 2 cm in diameter on computed tomography (CT). Results The study group was composed of 36 patients including 11 men and 25 women with a median age of 59.5 years (range, 34–77). Median follow-up duration of pure GGNs was 6 months (range, 0–63). Median maximum diameter of pure GGNs was 8.5 mm (range, 4–19). Pure GGNs were resected by wedge resection, segmentectomy, or lobectomy in 27 (61.4%), 10 (22.7%), and 7 (15.9%) cases, respectively. Pathologic diagnosis was atypical adenomatous hyperplasia, adenocarcinoma in situ, minimally invasive adenocarcinoma (MIA), or invasive adenocarcinoma (IA) in 1 (2.3%), 18 (40.9%), 15 (34.1%), and 10 (22.7%) cases, respectively. The optimal cutoff value for CT-maximal diameter to predict MIA or IA was 9.1 mm. In multivariate analyses, maximal CT-maximal diameter of GGNs ≥10 mm (odds ratio, 24.050; 95% confidence interval, 2.6–221.908; p = 0.005) emerged as significant independent predictor for either MIA or IA. Estimated risks of MIA or IA were 37.2, 59.3, 78.2, and 89.8% at maximal GGN diameters of 5, 10, 15, and 20 mm, respectively. Conclusion Pure GGNs were highly associated with lung adenocarcinoma in surgically resected cases, while estimated risk of GGNs invasiveness gradually increased as maximal diameter increased. ^* Both authors contributed equally to this work.