Association between chronic obstructive pulmonary disease and gastroesophageal reflux disease: a national cross-sectional cohort study

Association Between COPD and Hearing Loss

OBJECTIVE

The goal of the present study was to estimate the risk of hearing impairment in patients with COPD using huge nationwide population.

METHODS

A retrospective case-control study was performed using the National Health Insurance Database in South Korea from 2002 through 2019. Totally 614,370 COPD patients and matched 2,170,504 control participants were selected at a 1:4 ratio. Hearing impairment was defined based on the registered data in the Ministry of Health and Welfare of Korea with six levels of severity of hearing impairment. The propensity score was calculated, and overlap-weighted multinomial logistic regression was used to calculate the odds ratios of COPD for hearing impairment.

RESULTS

A total of 2.67% of COPD patients and 1.9% of control participants had hearing impairment. The COPD patients indicated 1.10-1.21 times higher odds for hearing impairment according to the severity of hearing impairment than the control group. In accordance with age and sex, the younger age group (<65 years old) and female group demonstrated higher odds for hearing impairment related to the presence of COPD. The high odds for hearing impairment in patients with COPD was consistent in all other subgroups, except for the underweight group.

CONCLUSIONS

COPD was associated with an increased risk of hearing impairment in the general population in Korea.

LEVEL OF EVIDENCE

3 Laryngoscope, 2024.

Airway pepsinogen A4 identifies lung transplant recipients with microaspiration and predicts chronic lung allograft dysfunction

BACKGROUND

Aspiration is a known risk factor for adverse outcomes post-lung transplantation. Airway bile acids are the gold-standard biomarker of aspiration; however, they are released into the duodenum and likely reflect concurrent gastrointestinal dysmotility. Previous studies investigating total airway pepsin have found conflicting results on its relationship with adverse outcomes post-lung transplantation. These studies measured total pepsin and pepsinogen in the airways. Certain pepsinogens are constitutively expressed in the lungs, while others, such as pepsinogen A4 (PGA4), are not. We sought to evaluate the utility of measuring airway PGA4 as a biomarker of aspiration and predictor of adverse outcomes in lung transplant recipients (LTRs) early post-transplant.

METHODS

Expression of PGA4 was compared to other pepsinogens in lung tissue. Total pepsin and PGA4 were measured in large airway bronchial washings and compared to preexisting markers of aspiration. Two independent cohorts of LTRs were used to assess the relationship between airway PGA4 and chronic lung allograft dysfunction (CLAD). Changes to airway PGA4 after antireflux surgery were assessed in a third cohort of LTRs.

RESULTS

PGA4 was expressed in healthy human stomach but not lung. Airway PGA4, but not total pepsin, was associated with aspiration. Airway PGA4 was associated with an increased risk of CLAD in two independent cohorts of LTRs. Antireflux surgery was associated with reduced airway PGA4.

CONCLUSIONS

Airway PGA4 is a marker of aspiration that predicts CLAD in LTRs. Measuring PGA4 at surveillance bronchoscopies can help triage high-risk LTRs for anti-reflux surgery.

Rate of severe exacerbations, healthcare resource utilisation and clinical outcomes in patients with COPD in low-income and middle-income countries: results from the EXACOS International Study

INTRODUCTION

The EXAcerbations of Chronic obstructive lung disease (COPD) and their OutcomeS (EXACOS) International Study aimed to quantify the rate of severe exacerbations and examine healthcare resource utilisation (HCRU) and clinical outcomes in patients with COPD from low-income and middle-income countries.

METHODS

EXACOS International was an observational, cross-sectional study with retrospective data collection from medical records for a period of up to 5 years. Data were collected from 12 countries: Argentina, Brazil, Chile, Colombia, Costa Rica, Dominican Republic, Guatemala, Hong Kong, Mexico, Panama, Russia and Taiwan. The study population comprised patients ≥40 years of age with COPD. Outcomes/variables included the prevalence of severe exacerbations, the annual rate of severe exacerbations and time between severe exacerbations; change in lung function over time (measured by the forced expiratory volume in 1 s (FEV1)); peripheral blood eosinophil counts (BECs) and the prevalence of comorbidities; treatment patterns; and HCRU.

RESULTS

In total, 1702 patients were included in the study. The study population had a mean age of 69.7 years, with 69.4% males, and a mean body mass index of 26.4 kg/m2. The mean annual prevalence of severe exacerbations was 20.1%, and 48.4% of patients experienced ≥1 severe exacerbation during the 5-year study period. As the number of severe exacerbations increased, the interval between successive exacerbations decreased. A statistically significant decrease in mean (SD) FEV1 from baseline to post-baseline was observed in patients with ≥1 severe exacerbation (1.23 (0.51) to 1.13 (0.52) L; p=0.0000). Mean BEC was 0.198 x109 cells/L, with 64.7% of patients having a BEC ≥0.1 x109 cells/L and 21.3% having a BEC ≥0.3 x109 cells/L. The most common comorbidity was hypertension (58.3%). An increasing number of severe exacerbations per year was associated with greater HCRU.

DISCUSSION

The findings presented here indicate that effective treatment strategies to prevent severe exacerbations in patients with COPD remain a significant unmet need in low-income and middle-income countries.

The Causal Relationship Between Gastroesophageal Reflux Disease and Chronic Obstructive Pulmonary Disease: A Bidirectional Two-Sample Mendelian Randomization Study

Background

Gastroesophageal reflux disease (GERD) and Chronic Obstructive Pulmonary Disease (COPD) often coexist and have been associated in observational studies. However, the real potential causal relationship between GERD and COPD is unknown and not well established.

Methods

In this study, we conducted a bidirectional two-sample Mendelian randomization(MR) to estimate whether GERD and COPD are causal. The GERD genetic data is from summary level data of a genome-wide association (GWAS) meta-analysis (Ncases = 71,522, Ncontrol=26,079). The COPD GWAS are available from the FinnGen (Ncases=16,410, Ncontrol=283,589). MR-Egger regression, Weighted Median, and Inverse-variance weighted (IVW) were used for MR analysis from the R package "TwoSampleMR", and IVW was the dominant estimation method. Additionally, the MR pleiotropy residual sum and outlier (MR-PRESSO), Cochran Q statistic, and leave-one-out analysis were used to detect and correct for the effect of heterogeneity and horizontal pleiotropy.

Results

MR analysis indicated that GERD was causally associated with an increased risk of COPD (IVW odds ratio (OR): 1.3760, 95% confidence interval (CI): 1.1565-1.6371, P=0.0003), and vice versa (IVW OR: 1.1728, 95% CI:1.0613-1.2961, P=0.0018). The analyses did not reveal any pleiotropy or heterogeneity.

Conclusion

Our study revealed possible evidence for a bidirectional causal relationship between GERD and COPD. Implementing screening and preventive strategies for GERD in individuals with COPD, and vice versa, will be crucial in future healthcare management. Further studies are needed to elucidate the mechanisms underlying the causal relationship between GERD and COPD.

The Association between Smoking Exposure and Reflux Esophagitis: A Cross-sectional Study among Men Conducted as a Part of Health Screening

Objective Gastroesophageal reflux disease (GERD), including reflux esophagitis (RE), is recognized as a common gastrointestinal disease, and its prevalence is reported to be increasing. While current cigarette smoking has been established as a risk factor for RE in several cross-sectional studies, most of these studies did not include details concerning the smoking status in their analyses. Smoking-related conditions, such as chronic lung disease and cough, are reportedly also related to GERD. Methods To investigate the association between RE and detailed smoking habits, we performed a cross-sectional analysis of healthy men enrolled in a comprehensive health checkup program conducted in 2015 that included esophago-gastro-duodenoscopy. Smoking status was assessed using a self-reported questionnaire. Other smoking-related parameters, including the lung function, cough symptoms and presence of chronic lung disease, were also assessed. Unconditional logistic regression was applied to calculate the odds ratio (OR) with 95% confidence intervals (CIs) after adjusting for confounding factors. Results The study included 151 subjects with RE (RE group) and 814 without RE (control group). Compared with never-smokers, former smokers (OR, 1.5; 95% CI, 0.9-2.9) and current smokers (OR, 2.4; 95% CI, 1.5-3.9) showed an increased risk of RE. An increased risk of RE was also observed among subjects with current smoking for 10-20 PYs and more than 20 PYs (OR, 2.8; 95% CI, 1.4-5.8, OR, 3.1; 95% CI, 1.6-5.7 respectively). An elevated risk was observed in former smokers who reported more than 20 PYs (OR, 2.5; 95% CI, 1.3-4.8). When former smokers were stratified according to time since smoking cessation, a significant RE risk was observed in participants who had stopped smoking less than 10 years earlier compared with never smokers (OR, 1.9; 95% CI, 1.1-3.3). No significant associations were observed between chronic cough, FEV1.0%, and RE. Conclusion Cumulative lifetime exposure to smoking plays an important role in the risk of RE.

Common gastrointestinal diseases and chronic obstructive pulmonary disease risk: a bidirectional Mendelian randomization analysis

Background: Observational studies suggest an association between gastrointestinal diseases and chronic obstructive pulmonary disease (COPD), but the causal relationship remains unclear. Methods: We conducted bidirectional Mendelian randomization (MR) analysis using summary data from genome-wide association study (GWAS) to explore the causal relationship between common gastrointestinal diseases and COPD. Gastrointestinal diseases included gastroesophageal reflux disease (GERD), peptic ulcer disease (PUD), irritable bowel syndrome (IBS), Crohn's disease (CD), ulcerative colitis (UC), functional dyspepsia (FD), non-infectious gastroenteritis (NGE), and constipation (CP). Significant MR analysis results were replicated in the COPD validation cohort. Results: Bidirectional MR analysis supported a bidirectional causal relationship between GERD and COPD, and COPD was also found to increase the risk of IBS and CP. Our study also provided evidence for a bidirectional causal relationship between PUD and COPD, although the strength of evidence may be insufficient. Furthermore, we provided evidence that there is no causal association between CD, UC, FD, NGE, and COPD. Conclusion: This study offers some evidence to clarify the causal relationship between common gastrointestinal diseases and COPD. Further research is needed to understand the underlying mechanisms of these associations.

Subtypes of Patients with Mild to Moderate Airflow Limitation as Predictors of Chronic Obstructive Pulmonary Disease Exacerbation

COPD is a heterogeneous disease, and its acute exacerbation is a major prognostic factor. We used cluster analysis to predict COPD exacerbation due to subtypes of mild-moderate airflow limitation. In all, 924 patients from the Korea COPD Subgroup Study cohort, with a forced expiratory volume (FEV1) ≥ 50% and documented age, body mass index (BMI), smoking status, smoking pack-years, COPD assessment test (CAT) score, predicted post-bronchodilator FEV1, were enrolled. Four groups, putative chronic bronchitis (n = 224), emphysema (n = 235), young smokers (n = 248), and near normal (n = 217), were identified. The chronic bronchitis group had the highest BMI, and the one with emphysema had the oldest age, lowest BMI, and highest smoking pack-years. The young smokers group had the youngest age and the highest proportion of current smokers. The near-normal group had the highest proportion of never-smokers and near-normal lung function. When compared with the near-normal group, the emphysema group had a higher risk of acute exacerbation (OR: 1.93, 95% CI: 1.29-2.88). However, multiple logistic regression showed that chronic bronchitis (OR: 2.887, 95% CI: 1.065-8.192), predicted functional residual capacity (OR: 1.023, 95% CI: 1.007-1.040), fibrinogen (OR: 1.004, 95% CI: 1.001-1.008), and gastroesophageal reflux disease were independent predictors of exacerbation (OR: 2.646, 95% CI: 1.142-6.181). The exacerbation-susceptible subtypes require more aggressive prevention strategies.

Elucidating the Link: Chronic Obstructive Pulmonary Disease and the Complex Interplay of Gastroesophageal Reflux Disease and Reflux-Related Complications

Background and Objective: Presenting chronic obstructive pulmonary disease (COPD) patients frequently report concurrent symptoms of gastroesophageal reflux disease (GERD). Few studies have shown a correlation between GERD and COPD. We aimed to examine the correlation between GERD and COPD as well as secondary related reflux complications, such as esophageal stricture, esophageal cancer, and Barrett's esophagus. Methods: This population-based analysis included 7,159,694 patients. Patients diagnosed with GERD with and without COPD were compared to those without GERD. The enrollment of COPD included centrilobular and panlobular emphysema and chronic bronchitis. Risk factors of COPD or GERD were used for adjustment. Bivariate analyses were performed using the chi-squared test or Fisher exact test (2-tailed) for categorical variables as appropriate to assess the differences in the groups. Results: Our results showed that COPD patients had a significantly higher incidence of GERD compared to those without COPD (27.8% vs. 14.1%, p < 0.01). After adjustment of demographics and risk factors, COPD patients had a 1.407 times higher risk of developing non-erosive esophagitis (p < 0.01), 1.165 higher risk of erosive esophagitis (p < 0.01), 1.399 times higher risk of esophageal stricture (p < 0.01), 1.354 times higher risk of Barrett's esophagus without dysplasia (p < 0.01), 1.327 times higher risk of Barrett's esophagus with dysplasia, as well as 1.235 times higher risk of esophageal cancer than those without COPD. Conclusions: Based on the evidence from this study, there are sufficient data to provide convincing evidence of an association between COPD and GERD and its secondary reflux-related complications.

Assessing the genetic relationship between gastroesophageal reflux disease and chronic respiratory diseases: a mendelian randomization study

BACKGROUND

Previous observational studies have found an association between gastroesophageal reflux disease (GERD) and chronic respiratory diseases, but it remains uncertain whether GERD causally influences these diseases. In this study, we aimed to estimate the causal associations between GERD and 5 chronic respiratory diseases.

METHODS

88 GERD-associated single nucleotide polymorphisms (SNPs) identified by the latest genome-wide association study were included as instrumental variables. Individual-level genetic summary data of participants were obtained from corresponding studies and the FinnGen consortium. We applied the inverse-variance weighted method to estimate the causality between genetically predicted GERD and 5 chronic respiratory diseases. Furthermore, the associations between GERD and common risk factors were investigated, and mediation analyses were conducted using multivariable MR. Various sensitivity analyses were also performed to verify the robustness of the findings.

RESULTS

Our study demonstrated that genetically predicted GERD was causally associated with an increased risk of asthma (OR 1.39, 95%CI 1.25-1.56, P < 0.001), idiopathic pulmonary fibrosis (IPF) (OR 1.43, 95%CI 1.05-1.95, P = 0.022), chronic obstructive disease (COPD) (OR 1.64, 95%CI 1.41-1.93, P < 0.001), chronic bronchitis (OR 1.77, 95%CI 1.15-2.74, P = 0.009), while no correlation was observed for bronchiectasis (OR 0.93, 95%CI 0.68-1.27, P = 0.645). Additionally, GERD was associated with 12 common risk factors for chronic respiratory diseases. Nevertheless, no significant mediators were discovered.

CONCLUSIONS

Our study suggested that GERD was a causal factor in the development of asthma, IPF, COPD and chronic bronchitis, indicating that GERD-associated micro-aspiration of gastric contents process might play a role in the development of pulmonary fibrosis in these diseases.

Smoking cessation after diagnosis of COPD is associated with lower all-cause and cause-specific mortality: a nationwide population-based cohort study of South Korean men

BACKGROUND

The most effective way to halt the advancement of COPD is smoking cessation. However, limited data are available on the question of whether quitting smoking within two years after COPD diagnosis reduces the risk of mortality. The goal of our research was to analyze the relationship between quitting smoking after COPD diagnosis and the risks of all-cause and cause-specific mortality, using the Korean National Health Insurance Service (NHIS) database.

METHODS

This study included 1,740 male COPD patients aged 40 years or more who had been newly diagnosed within the 2003-2014 time period and had smoked prior to their COPD diagnosis. The patients were categorized into two groups according to their smoking status after COPD diagnosis: (i) persistent smokers (ii) quitters (smoking cessation within two years of COPD diagnosis). Multivariate Cox proportional hazard regression was performed to determine the adjusted hazard ratio (HR) and 95% confidence interval (CI) for both all-cause and cause-specific mortality.

RESULTS

Among 1,740 patients (mean age, 64.6 years; mean follow-up duration, 7.6 years), 30.5% stopped smoking after COPD diagnosis. Quitters gained a 17% risk reduction in all-cause mortality (aHR, 0.83; 95% CI, 0.69-1.00) and a 44% risk reduction in cardiovascular mortality (aHR, 0.56; 95% CI, 0.33-0.95) compared with persistent smokers.

CONCLUSION

Our study found that patients who quit smoking within two years after COPD diagnosis had lower risks of all-cause and cardiovascular mortality relative to persistent smokers. These results can be used to encourage newly diagnosed COPD patients to stop smoking.

Possible Incidental Parkinson's Disease following Asthma: A Nested Case-Control Study in Korea

A connection between asthma and the occurrence of Parkinson's disease (PD) has been suggested, but the findings have been contentious and require verification. In this nested case-control study using data from the Korean National Health Insurance Service-Health Screening Cohort (2002-2019), which comprised 9029 participants with PD and 36,116 matched controls, we explored the relationship between asthma and incident PD. An overlap-weighted logistic regression model was used to measure the probability of asthma and PD. After adjusting for various covariates, we found that asthma was related to a 1.11-fold greater probability of PD (95% confidence interval: 1.06-1.16). A subgroup analysis showed that this effect was independent of age, sex, residential area, or alcohol consumption, and that it was still noticeable even among patients with a high income; those with a normal weight or obesity; those who were non-smokers or current smokers; and those with no history of chronic obstructive pulmonary disease, hypertension, hyperglycemia, hyperlipidemia, or anemia. Thus, these findings may indicate that asthma may slightly augment the likelihood of PD in the Korean adult population regardless of demographic or lifestyle factors, making it difficult to predict PD in asthma patients.

Pharmacological, Nutritional, and Rehabilitative Interventions to Improve the Complex Management of Osteoporosis in Patients with Chronic Obstructive Pulmonary Disease: A Narrative Review

Osteoporosis is a highly prevalent condition affecting a growing number of patients affected by chronic obstructive pulmonary disease (COPD), with crucial implications for risk of fragility fractures, hospitalization, and mortality. Several risk factors have been identified to have a role in osteoporosis development in COPD patients, including corticosteroid therapy, systemic inflammation, smoke, physical activity levels, malnutrition, and sarcopenia. In this scenario, a personalized multitarget intervention focusing on the pathological mechanisms underpinning osteoporosis is mandatory to improve bone health in these frail patients. Specifically, physical exercise, nutritional approach, dietary supplements, and smoke cessation are the cornerstone of the lifestyle approach to osteoporosis in COPD patients, improving not only bone health but also physical performance and balance. On the other hand, pharmacological treatment should be considered for both the prevention and treatment of osteoporosis in patients at higher risk of fragility fractures. Despite these considerations, several barriers still affect the integration of a personalized approach to managing osteoporosis in COPD patients. However, digital innovation solutions and telemedicine might have a role in optimizing sustainable networking between hospital assistance and community settings to improve bone health and reduce sanitary costs of the long-term management of COPD patients with osteoporosis.

Gastroesophageal Reflux Disease in Idiopathic Pulmonary Fibrosis: Viewer or Actor? To Treat or Not to Treat?

Background: Idiopathic pulmonary fibrosis (IPF) is a rare and severe disease with a median survival of ∼3 years. Several risk factors have been identified, such as age, genetic predisposition, tobacco exposure, and gastro-oesophageal reflux disease (GERD). Prevalence of GERD in IPF is high and may affect 87% of patients, of whom only half (47%) report symptoms. Objective: The aim of this study is to review current evidence regarding the correlation between GERD and IPF and to evaluate the current studies regarding treatments for GERD-IPF. Methods: A review to identify research papers documenting an association between GERD and IPF was performed. Results: We identified several studies that have confirmed the association between GERD and IPF, with an increased acid exposure, risk of gastric aspiration and bile acids levels in these patients. Few studies focused their attention on GERD treatment, showing how antiacid therapy was not able to change IPF evolution. Conclusions: This review investigating the correlation between GERD and IPF has confirmed the hypothesized association. However, further large prospective studies are needed to corroborate and elucidate these findings with a focus on preventative and treatment strategies.

Elevated risk of acute epiglottitis in patients with chronic obstructive pulmonary disease: A nationwide cohort study

Objective

In individuals with epiglottitis, chronic obstructive pulmonary disease (COPD) is a common comorbidity; however, the impact of COPD under such circumstances is not well documented. Therefore, we performed this population-based study to determine whether, in adults, COPD is a risk factor for epiglottitis.

Methods

In this retrospective matched-cohort study, data obtained from the Taiwan National Health Insurance Research Database were analyzed. We identified all patients newly diagnosed as having COPD in 2000–2011 and performed frequency matching and propensity-score matching for every patient with COPD individually to another patient without a COPD diagnosis. We used epiglottitis occurrence as the study endpoint, and we investigated the hazard ratio of epiglottitis by using the Cox proportional hazards model after adjustment for potential confounders.

Results

In the frequency matching, the cumulative epiglottitis incidence was significantly higher (p = 0.005) in the COPD cohort. According to the adjusted Cox proportional hazard model, COPD exhibited a significant association with elevated epiglottitis incidence (adjusted hazard ratio: 1.76; 95% confidence interval: 1.15–2.70, p = 0.009). Similar trend was observed in the propensity-score matching analysis (adjusted hazard ratio: 1.50; 95% confidence interval: 0.99–2.29, p = 0.057). Our subgroup analysis revealed COPD to be an epiglottitis risk factor in male patients and those aged 40–64 years.

Conclusions

This is the first nationwide matched-cohort research to examine the association of COPD with epiglottitis. Our results revealed that COPD may be a potential risk factor for epiglottitis; thus, clinicians should be mindful of the potential increased risk of epiglottitis following COPD.

Associations Between Asthma Diagnosis/Asthma Exacerbation and Previous Proton-Pump Inhibitor use: A Nested Case-Control Study Using a National Health Screening Cohort

Background: Proton-pump inhibitors (PPIs) block acid secretion from gastric parietal cells; however, recent studies have reported that PPIs have antioxidant and anti-inflammatory properties in various cells. Newer PPIs are stronger inhibitors of acid secretion; however, the anti-inflammatory effects of these drugs have not been assessed. We evaluated anti-inflammatory effect of PPIs on the development of asthma/asthma exacerbation (AE) in a national health screening cohort.

Methods: This case-control study comprised 64,809 participants with asthma who were 1:1 matched with controls from the Korean National Health Insurance Service-Health Screening Cohort. Conditional logistic regression analysis was used to evaluate the effect of previous PPI use on an asthma diagnosis in all participants. Unconditional logistic regression was used to assess the effect of PPI use on AE in participants with asthma. These relationships were estimated in a subgroup analysis according to PPI generation.

Results: Overall, PPI use increased the risk of asthma diagnosis [adjusted odds ratio (aOR) = 1.29, 95% confidence interval (CI) = 1.23–1.35, p < 0.001]. Use of the first-generation PPIs was associated with asthma (aOR = 1.34, 95% CI = 1.18–1.52, p < 0.001), while use of second-generation PPIs was not (aOR = 0.97, 95% CI = 0.82–1.15, p = 0.748). In contrast, overall PPI use decreased the risk of AE in participants with asthma (aOR = 0.79, 95% CI = 0.75–0.84, p < 0.001), although this effect was observed only for second-generation PPIs (aOR = 0.76, 95% CI = 0.65–0.89, p = 0.001).

Conclusion: PPI use increased the risk for subsequent asthma diagnosis. However, this effect was confined to first-generation PPIs. Second-generation PPIs decreased the risk of AE.

The association between chronic rhinosinusitis and proton pump inhibitor use: a nested case-control study using a health screening cohort

This study aimed to evaluate the relationship between chronic rhinosinusitis (CRS) and proton pump inhibitor (PPI) use in a Korean population. The Korea National Health Insurance Service-National Sample Cohort was assessed from 2002 to 2013. Patients with CRS (n = 7194) and control participants (n = 28,776) were matched by random order at a 1:4 ratio for age, sex, income group, region of residence, and index date. We analyzed PPI use by patients with and without CRS. ICD-10 codes defined CRS, and claim codes defined previous PPI use. Conditional logistic regression analyzed the crude and adjusted odds ratios (ORs) with 95% confidence intervals (CI). Subgroup analyses were performed according to age and sex. There was a difference in PPI prescription history and prescription duration between the CRS and control groups. The rate of CRS was higher in current (33.8% [263/778]) and past (26.3% [713/2708]) PPI users than PPI non-users (19.1% [6218/32,484], P < 0.001). The adjusted OR (aOR) of CRS with/without nasal polyps was 1.71 (95% CI 1.46–2.02, P < 0.001) and 1.28 (95% CI 1.16–1.41, P < 0.001) in current and past PPI users, respectively. Irrespective of PPI prescription days, PPI use was associated with higher CRS occurrence (aOR 1.46; 95% CI 1.26–1.69, P < 0.001) in the 30–89-day PPI user group. The subgroup analyses results were consistent. The ORs of CRS were higher in PPI users than in the controls, and consistently so in all age and sex groups.

Association between asthma or chronic obstructive pulmonary disease and chronic otitis media

We hypothesized that asthma/chronic obstructive pulmonary disease (COPD) might increase the risk of chronic otitis media (COM), as asthma or COPD affects other diseases. The aim of this research was to investigate whether the incidence of COM is affected by a diagnosis of asthma or COPD in patients compared to matched controls from the national health screening cohort. A COM group (n = 11,587) and a control group that was 1:4 matched for age, sex, income, and residence area (n = 46,348) were selected. The control group included participants who never received treatment for COM from Korean National Health Insurance Service-Health Screening Cohort from 2002 to 2015. The crude and adjusted odds ratios (ORs) of previous asthma/COPD before the index date for COM were analyzed using conditional logistic regression. The analyses were stratified by age, sex, income, and region of residence. The period prevalence of asthma (17.5% vs. 14.3%, p < 0.001) and COPD (6.6% vs. 5.0%, p < 0.001) were significantly higher in the COM group than in the control group. In addition, the odds of asthma and COPD were significantly higher in the COM group than in the control group. Both asthma (adjusted OR 1.23, 95% confidence interval [CI] 1.16-1.31, p < 0.001) and COPD (adjusted OR 1.23, 95% CI 1.13-1.35, p < 0.001) increased the ORs for COM. This positive association between asthma/COPD and COM indicates that asthma/COPD might increase the incidence of COM.

Increased hospitalizations and economic burden in COPD with bronchiectasis: a nationwide representative study

With the increasing use of computed tomography, bronchiectasis has become a common finding in patients with chronic obstructive pulmonary disease (COPD). However, the clinical aspects and medical utilization of COPD with bronchiectasis (BE) remain unclear. We aimed to investigate the BE effect on prognosis and medical utilization in patients with COPD. Among 263,747 COPD patients, we excluded patients lacking chest X-ray, CT, or pulmonary function test codes and classified 2583 GOLD-C/D patients matched according to age, sex, and medical aid as having COPD-BE (447 [17.3%]) and COPD without BE (2136 [82.7%]). Patients with COPD-BE showed a higher rate of acute exacerbation requiring antibiotics than those without BE. Moreover, multivariable analysis showed that BE co-existence was a crucial factor for moderate-to-severe exacerbation (incidence rate ratio [IRR] 1.071; 95% CI 1.012-1.134; p = 0.019). Patients with COPD-BE had a significantly higher rate of exacerbations requiring antibiotics, as well as treatment cost and duration (meant as number of days using hospitalization plus outpatient appointment), than those with COPD without BE (52.64 ± 65.29 vs. 40.19 ± 50.02 days, p < 0.001; 5984.08 ± 8316.96 vs. 4453.40 ± 7291.03 USD, p < 0.001). Compared with patients with COPD without BE, patients with COPD-BE experienced more exacerbations requiring antibiotics, more hospitalizations, and a higher medical cost.

Short-Term Air Pollution Exposure and Risk of Acute Exacerbation of Chronic Obstructive Pulmonary Disease in Korea: A National Time-Stratified Case-Crossover Study

We investigated the association between short-term exposure to air pollution and the risk of acute exacerbation of chronic obstructive pulmonary disease (AE-COPD) in seven metropolitan cities in Korea. We used national health insurance claims data to identify AE-COPD cases in 2015. We estimated short-term exposure to particulate matter (PM) with a diameter of ≤2.5 μm (PM_2.5), PM with diameters of ≤10 μm (PM₁₀), sulfur dioxide (SO₂), nitrogen dioxide (NO₂), carbon monoxide (CO), and ozone (O₃) obtained from the Ministry of Environment. We conducted a time-stratified, case-crossover study to evaluate the effect of short-term exposure to air pollution on hospital visits for AE-COPD, using a conditional logistic regression model. The risk of hospital visits for AE-COPD was significantly associated with interquartile range increases in PM₁₀ in a cumulative lag model (lag 0–2, 0.35%, 95% confidence interval (CI) 0.06–0.65%; lag 0–3, 0.39%, 95% CI 0.01–0.77%). The associations were higher among patients who were men, aged 40–64 years, with low household income, and with a history of asthma. However, other air pollutants were not significantly associated with the risk of hospital visits for AE-COPD. Short-term exposure to air pollution, especially PM₁₀, increases the risk of hospital visits for AE-COPD.

Association Between Asthma and Meniere's Disease: A Nested Case-Control Study

OBJECTIVES/HYPOTHESIS

This study aimed to investigate the association between Meniere's disease and prior history of asthma.

STUDY DESIGN

A nested case-control study.

METHODS

Among the patients aged ≥40 years from the Korean National Health Insurance Service-Health Screening Cohort 2002-2015, 7,734 diagnosed with Meniere's disease between 2004 and 2015 were enrolled in this study. From the 505,834 participants without a prior history of Meniere's disease, 30,936 control participants were selected based on age, sex, income, and region of residence. The presence of a prior history of asthma before the diagnosis of Meniere's disease was compared between the Meniere's disease group and control group using conditional logistic regression with odds ratios (ORs) and 95% confidence intervals (95% CIs).

RESULTS

Prior history of asthma was associated with 1.30 (1.21-1.39) times higher odds of Meniere's disease (E-value = 1.92 [1.71]). Both allergic asthma and nonallergic asthma patients demonstrated higher odds of Meniere's disease than the control group (adjusted OR = 1.21 [1.08-1.36] and E-value = 1.72 [1.37] for allergic asthma; adjusted OR = 1.26 [1.17-1.36] and E-value = 1.83 [1.60] for nonallergic asthma).

CONCLUSIONS

This study is the first to demonstrate a positive relationship between Meniere's disease and prior asthma history in adults. The association between prior asthma history and Meniere's disease was noted in both allergic and nonallergic asthma cases. The potential development of Meniere's disease should be considered when managing the asthma patients with dizziness or vertigo.

LEVEL OF EVIDENCE

3 Laryngoscope, 2021.

Acute Exacerbation of Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality worldwide and results in an economic and social burden that is both substantial and increasing. The natural history of COPD is punctuated by exacerbations, which have major short- and long-term implications on the patient and health care system. Evidence-based guidelines stipulate that early detection and prompt treatment of exacerbations are essential to ensure optimal outcomes and to reduce the burden of COPD. In this review, we provide a concise overview of COPD exacerbations and their risk factors and etiology (infection vs noninfectious), outlining the initial evaluation, triaging, and current management including invasive and noninvasive ventilation, in addition to the prognosis and the preventive strategies.

Reflux esophagitis in patients with chronic obstructive pulmonary disease

The relationship between chronic obstructive pulmonary disease (COPD) and reflux esophagitis (RE) was controversial. We investigated the factors influencing RE development in patients with COPD and evaluated the association between RE and AECOPD.Patients with COPD who underwent esophagogastroduodenoscopy from January 2003 to December 2013 in St. Paul's Hospital, the Catholic University of Korea (Seoul, Korea) were enrolled retrospectively. The grade of RE was based on the Los Angeles classification and minimal change esophagitis. Body mass index, smoking history, medical history, AECOPD, pulmonary function test data, endoscopic findings, and comorbidities were reviewed.Of a total of 218 patients with COPD, 111 (50.9%) were diagnosed with RE. None of age, sex, smoking history, or the severity of airflow limitation was associated with RE. AECOPD was not related to either the presence or severity of RE. There was no significant correlation between RE grade by Los Angeles classification and severity of airflow limitation (P = .625). Those who had RE used theophylline (P = .003) and long-acting muscarinic antagonists (P = .026) significantly more often than did controls. The use of theophylline (OR 2.05; 95% CI, 1.16-3.65, P = .014) was associated with an increased incidence of RE.The use of theophylline might increase the risk of RE in COPD patients. RE may not be associated with airflow limitation or AECOPD.

Systems Biology and Bile Acid Signalling in Microbiome-Host Interactions in the Cystic Fibrosis Lung

The study of the respiratory microbiota has revealed that the lungs of healthy and diseased individuals harbour distinct microbial communities. Imbalances in these communities can contribute to the pathogenesis of lung disease. How these imbalances occur and establish is largely unknown. This review is focused on the genetically inherited condition of Cystic Fibrosis (CF). Understanding the microbial and host-related factors that govern the establishment of chronic CF lung inflammation and pathogen colonisation is essential. Specifically, dissecting the interplay in the inflammation–pathogen–host axis. Bile acids are important host derived and microbially modified signal molecules that have been detected in CF lungs. These bile acids are associated with inflammation and restructuring of the lung microbiota linked to chronicity. This community remodelling involves a switch in the lung microbiota from a high biodiversity/low pathogen state to a low biodiversity/pathogen-dominated state. Bile acids are particularly associated with the dominance of Proteobacterial pathogens. The ability of bile acids to impact directly on both the lung microbiota and the host response offers a unifying principle underpinning the pathogenesis of CF. The modulating role of bile acids in lung microbiota dysbiosis and inflammation could offer new potential targets for designing innovative therapeutic approaches for respiratory disease.

Association between Chronic Obstructive Pulmonary Disease and Ménière's Disease: A Nested Case-Control Study Using a National Health Screening Cohort

This study explored the relation between Ménière's disease and chronic obstructive pulmonary disease (COPD). The ≥40-year-old population of the Korean National Health Insurance Service-Health Screening Cohort was included. In total, 7734 Ménière's disease patients and 30,936 control participants were enrolled. Control participants were matched for age, sex, income, and region of residence with Ménière's disease participants. The odds of having Ménière's disease given a history of COPD were analyzed using conditional logistic regression. Subgroup analyses were conducted according to age, sex, income, and region of residence. The odds of having Ménière's disease were found to be 1.18-fold higher with a history of COPD than with no history of COPD (95% confidence intervals (CI) = 1.06-1.32, E-value (CI) = 1.64 (1.31)). The ≥60 years old, male, low-income, and rural subgroups showed increased odds of developing Ménière's disease when a history of COPD was reported. A history of COPD was associated with an increased risk of Ménière's disease in the adult population.

Proton pump inhibitor treatment improves pulmonary function in acute exacerbations of COPD patients with 24-hour Dx-pH monitoring-diagnosed laryngopharyngeal reflux

OBJECTIVES

Chronic obstructive pulmonary disease (COPD) patients have higher laryngopharyngeal reflux (LPR)-related symptom incidence. But LPR treatment is empirical. We aimed to determine the frequency of LPR, diagnosed by 24-hour Dx-pH monitoring, among acute exacerbations of COPD (AECOPD) patients with Reflux Symptom Index (RSI) ≥13 and investigate proton pump inhibitor (PPI) treatment effect on LPR, COPD symptoms, and pulmonary function.

METHODS

From January 2016 to September 2017, 102 AECOPD patients with RSI ≥13 were enrolled. COPD assessment test (CAT), mMRC dyspnea scale, pulmonary function tests, and 24-hour Dx-pH monitoring were performed. The Ryan score was evaluated by using the Dx-pH DataView Lite software, which identifies patients with abnormal pharyngeal pH environments. Associations among RSI, pulmonary function test results, and Ryan score parameters were evaluated. The abovementioned assessments were reperformed after treatment, and pre- and posttreatment data were compared.

RESULTS

Of the 102 eligible patients, 49 (48.04%) were diagnosed with LPR based on Ryan score. Percentage of the forced expiratory volume at 1 second (FEV1%) was significantly worse in Ryan-positive than in Ryan-negative AECOPD patients. There were significant negative correlations between FEV1% and Ryan score (r = -0.394, P < 0.001), FEV1% and % time below pH threshold (r = -0.371, P < 0.001) in upright position but not in supine position. There was no significant correlation between RSI and Ryan score parameters. There were significant improvements in RSI, mMRC, CAT, and FEV1% in Ryan-positive AECOPD patients after PPI and basic treatments.

CONCLUSION

Study results indicate unreliability of RSI threshold for LPR diagnosis. Combination of symptoms, endoscopic findings, and 24-hour Dx-pH monitoring is recommended for LPR diagnosis and PPI treatment decisions, especially in difficult-to-control or severe COPD patients.

Endoscopic evaluation of pharyngeal and laryngeal sensation in patients with chronic obstructive pulmonary disease (COPD): A cross-sectional study

OBJECTIVE

To describe and compare the findings of endoscopic sensory assessment in COPD patients and healthy controls.

DESIGN

A prospective cross-sectional study.

SETTING

Otorhinolaryngology outpatient clinic at a university hospital.

PARTICIPANTS

27 adults with COPD and 11 age-matched healthy controls.

MAIN OUTCOME MEASURES

Group differences in light touch endoscopic tests of pharyngeal and laryngeal sensation, controlling for pooled salivary secretions in the pharynx and laryngo-pharyngeal reflux as measured by the Reflux Finding Score (RFS).

RESULTS

A significant difference in laryngeal sensation was found between the study groups (P = .047), with reduced laryngeal sensation in the COPD patients. Additionally, a significant relationship was found between impaired oropharyngeal sensation and the presence of pooled salivary secretions in the pharynx (P = .018), especially in the pyriform sinuses (P = .012). No differences in the frequency of abnormal RFSs were found between groups.

CONCLUSION

Individuals with COPD were significantly more likely to present with impaired laryngeal sensation. Additionally, impaired sensation in the oropharynx was associated with pooled salivary secretions in the pharynx.

Nationwide quality assessment of treatment for chronic obstructive pulmonary disease

Background

Chronic obstructive pulmonary disease (COPD) requires careful ambulatory care. If treatment is effective, exacerbation and hospitalization can be preventable. Appropriate management is important; the disease prevalence is high, as is the demand on healthcare resources. Here, we have reported the results of nationwide quality assessment performed with the aims of improving patient management, reducing progression to severe status, and minimizing medical care expenses.

Methods

The Health Insurance Review and Assessment Service (HIRA) engaged in quality assessment three times from May 2014 to April 2017. Medical care institutions were evaluated in terms of the pulmonary function test (PFT), patient revisit, and inhaled bronchodilator prescription rates.

Results

The numbers of patients assessed were 141,782, 142,790, and 143,339 in years 1, 2, and 3, respectively; the numbers of medical care institutions assessed were 6,691, 6,722, and 6,470, respectively. The PFT implementation rates were 58.7%, 62.5%, and 67.9% for years 1, 2, and 3, respectively; these rates were highest for tertiary hospitals, followed by general and local hospitals, as well as primary healthcare clinics. The repeat visit rates were 85.5%, 92.1%, and 85.0% for years 1, 2, and 3, respectively; these rates were highest for general hospitals, followed by local and tertiary hospitals, and primary healthcare clinics. The inhaled bronchodilator prescription rates were 67.9%, 71.2%, and 76.9% for years 1, 2, and 3, respectively; these rates increased with increasing hospital grade.

Conclusions

The PFT and inhaled bronchodilator prescription rates improved over the 3-year nationwide quality assessment period.

Pharmacology and Therapeutics of Bronchodilators Revisited

Bronchodilators remain the cornerstone of the treatment of airway disorders such as asthma and chronic obstructive pulmonary disease (COPD). There is therefore considerable interest in understanding how to optimize the use of our existing classes of bronchodilator and in identifying novel classes of bronchodilator drugs. However, new classes of bronchodilator have proved challenging to develop because many of these have no better efficacy than existing classes of bronchodilator and often have unacceptable safety profiles. Recent research has shown that optimization of bronchodilation occurs when both arms of the autonomic nervous system are affected through antagonism of muscarinic receptors to reduce the influence of parasympathetic innervation of the lung and through stimulation of β ₂-adrenoceptors (β ₂-ARs) on airway smooth muscle with β ₂-AR-selective agonists to mimic the sympathetic influence on the lung. This is currently achieved by use of fixed-dose combinations of inhaled long-acting β ₂-adrenoceptor agonists (LABAs) and long-acting muscarinic acetylcholine receptor antagonists (LAMAs). Due to the distinct mechanisms of action of LAMAs and LABAs, the additive/synergistic effects of using these drug classes together has been extensively investigated. More recently, so-called "triple inhalers" containing fixed-dose combinations of both classes of bronchodilator (dual bronchodilation) and an inhaled corticosteroid in the same inhaler have been developed. Furthermore, a number of so-called "bifunctional drugs" having two different primary pharmacological actions in the same molecule are under development. This review discusses recent advancements in knowledge on bronchodilators and bifunctional drugs for the treatment of asthma and COPD. SIGNIFICANCE STATEMENT: Since our last review in 2012, there has been considerable research to identify novel classes of bronchodilator drugs, to further understand how to optimize the use of the existing classes of bronchodilator, and to better understand the role of bifunctional drugs in the treatment of asthma and chronic obstructive pulmonary disease.

Irritable bowel syndrome increases the risk of chronic obstructive pulmonary disease: A retrospective cohort study

Both inflammation and infection are associated with the development of irritable bowel syndrome (IBS) and chronic obstructive pulmonary disease (COPD). The purpose of this study is to further elucidate the association between IBS and COPD through a retrospective cohort study. We enrolled IBS patients diagnosed between 2000 and 2011 with follow-up for at least one year. The non-IBS patients as comparison group were selected with 1:3 matching by propensity score. Statistical analysis was utilized to assess the differences in characteristic distribution, and to compare the cumulative incidence of COPD between the IBS and non-IBS cohorts. We selected 14,021 IBS patients and 42,068 non-IBS patients for comparison. The IBS patients exhibited a significant risk to develop COPD compared with non-IBS patients. Additionally, the cumulative incidence rate of COPD in the IBS cohort increased significantly during the follow-up period of more than ten years, compared to the non-IBS cohort, based on the Kaplan-Meier analysis. The risk of COPD was also significantly decreased in those patients with more than eighteen IBS-related clinical visits. This retrospective cohort study demonstrates the significantly increased risk of COPD in patients with IBS. Therefore, early inspection and prevention of COPD is essential for patients with IBS.

Management of the COPD Patient with Comorbidities: An Experts Recommendation Document

Background

Chronic obstructive pulmonary disease (COPD) is associated with multiple comorbidities, which impact negatively on patients and are often underdiagnosed, thus lacking a proper management due to the absence of clear guidelines.

Purpose

To elaborate expert recommendations aimed to help healthcare professionals to provide the right care for treating COPD patients with comorbidities.

Methods

A modified RAND-UCLA appropriateness method consisting of nominal groups to draw up consensus recommendations (6 Spanish experts) and 2-Delphi rounds to validate them (23 Spanish experts) was performed.

Results

A panel of Spanish internal medicine experts reached consensus on 73 recommendations and 81 conclusions on the clinical consequences of the presence of comorbidities. In general, the experts reached consensus on the issues raised with regard to cardiovascular comorbidity and metabolic disorders. Consensus was reached on the use of selective serotonin reuptake inhibitors in cases of depression and the usefulness of referring patients with anxiety to respiratory rehabilitation programmes. The results also showed consensus on the usefulness of investigating the quality of sleep, the treatment of pain with opioids and the evaluation of osteoporosis by lateral chest radiography.

Conclusion

This study provides conclusions and recommendations that are intended to improve the management of the complexity of patients with COPD and important comorbidities, usually excluded from clinical trials.

A systematic review with meta-analysis of gastroesophageal reflux disease and exacerbations of chronic obstructive pulmonary disease

Background

Gastroesophageal reflux disease (GERD) was suggested to be associated with exacerbations of chronic obstructive pulmonary disease (COPD) in recent years. The aim of this study was to examine the association between GERD and COPD exacerbation through a meta-analysis.

Methods

Databases including EMBASE, MEDLINE, and the Cochrane Central Register of Controlled Trials were searched with a systematic searching strategy for original articles, published until Jan 2019, without language restriction.

Results

A total of 13,245 patients from 10 observational articles were included in the meta-analysis. The meta-analysis indicated that GERD is associated with increased risk of COPD exacerbation (OR: 5.37; 95% CI 2.71–10.64). Patients with COPD and GERD had increased number of exacerbation (WMD: 0.48; 95% CI: 0.31 to 0.65).

Conclusions

The meta-analysis showed that there was a significant correlation between GERD and COPD exacerbation.

Risk of inflammatory bowel disease in patients with chronic obstructive pulmonary disease: A nationwide, population-based study

BACKGROUND

There is a growing evidence regarding an increased risk of inflammatory bowel disease (IBD) among patients with airway diseases.

AIM

To investigate the influence of chronic obstructive pulmonary disease (COPD) on the risk of IBD.

METHODS

A nationwide, population-based study was conducted using data from the National Health Insurance Service database. A total of 1303021 patients with COPD and 6515105 non-COPD controls were identified. The COPD group was divided into the severe and the mild COPD group according to diagnostic criteria. The risk of IBD in patients with COPD compared to controls was analyzed by Cox proportional hazard regression models. The cumulative incidences of IBD were compared between the groups.

RESULTS

The COPD group had higher incidences of IBD compared to non-COPD controls (incidence rate, 9.98 vs 7.18 per 100000 person-years, P < 0.001). The risk of IBD in the COPD group was increased by 1.38 (adjusted hazard ratio (HR); 95%CI: 1.25-1.52). The incidence rate of IBD was higher in the severe COPD group than in the mild COPD group (12.39 vs 9.77 per 100000 person-year, P < 0.001). The severity of COPD was associated with an increased risk of IBD (adjusted HR 1.70 in severe COPD, 95%CI: 1.27-2.21 and adjusted HR 1.35 in mild COPD, 95%CI: 1.22-1.49)

CONCLUSION

The incidences of IBD were significantly increased in COPD patients in South Korea and the risk of developing IBD also increased as the severity of COPD increased.

Bidirectional Association Between GERD and Asthma: Two Longitudinal Follow-Up Studies Using a National Sample Cohort

BACKGROUND

A relation between gastroesophageal reflux disease (GERD) and asthma has been suggested; however, causality has not been investigated.

OBJECTIVE

This study aimed to delineate the causal relation between GERD and asthma.

METHODS

Participants of the Korean National Health Insurance Service-National Sample Cohort 2002-2013 who were ≥20 years old were selected for this study. In study I, 116,502 patients with GERD were matched in a 1:2 ratio to 233,004 control I participants, and the hazard ratio (HR) of asthma in patients with GERD was analyzed. In study II, 104,146 patients with asthma were matched in a 1:1 ratio to 104,146 control II participants, and the HR for GERD in patients with asthma was analyzed. A stratified Cox-proportional hazards model was used. Subgroup analyses were performed according to age and sex.

RESULTS

In study I, 12.5% (14,595 of 116,502) of the GERD group and 7.8% (18,135 of 233,004) of the control I group presented asthma (P < .001). The GERD group demonstrated a 1.46-fold higher HR for asthma than the control I group (95% confidence interval [CI] = 1.42-1.49, P < .001). In study II, 16.9% (17,582 of 104,146) of the asthma group and 11.9% (12,393 of 104,146) of the control II group presented GERD (P < .001). The asthma group showed a 1.36-fold higher HR for GERD than the control II group (95% CI = 1.33-1.39, P < .001). All age and sex subgroups presented consistent results.

CONCLUSION

GERD and asthma had a bidirectional relation in the study population.

Impact of chronic obstructive pulmonary disease on mortality: A large national cohort study

BACKGROUND AND OBJECTIVE

The global burden of chronic obstructive pulmonary disease (COPD) is increasing and COPD patients are at higher risk for all-cause mortality. We aimed to evaluate the impact of COPD on specific-cause mortality using national data.

METHODS

This was nationwide retrospective cohort study of 340, 767 adults aged 40-84 years who lacked COPD diagnosis at baseline between 1 January 2003 and 31 December 2013. Incident COPD was defined by reference to COPD claim codes and prescription of COPD medication at least twice annually. Cox proportional hazard ratio (HR) for each cause of death in the COPD group was compared to that of the non-COPD group, with other causes of death accounted as the competing risk.

RESULTS

All-cause mortality was higher in the COPD (2,978 per 100, 000 person-years) than the non-COPD group (629 per 100, 000 person-years) and adjusted HR was 1.41 (95% CI = 1.32, 1.50). The association was particularly strong for chronic lower airway disease (adjusted sub-HR = 9.67; 95% CI = 7.21, 12.96) and lung cancer (adjusted sub-HR = 3.16; 95% CI = 2.68, 3.71), and the association was stronger in those aged <60 years.

CONCLUSION

In this large national cohort, COPD patients were at a statistically significant higher risk for all-cause mortality than those without COPD. They were more likely to die from chronic lower airway disease, lung cancer and pneumonia than subjects without COPD. The impact of COPD on specific mortalities was stronger in younger subjects.

Prediction of first acute exacerbation using COPD subtypes identified by cluster analysis

Purpose

In patients with COPD, acute exacerbation (AE) is not only an important determinant of prognosis, but also an important factor in choosing therapeutic agents. In this study, we evaluated the usefulness of COPD subtypes identified through cluster analysis to predict the first AE.

Patients and methods

Among COPD patients in the Korea COPD Subgroup Study (KOCOSS) cohort, 1,195 who had follow-up data for AE were included in our study. We selected seven variables for cluster analysis – age, body mass index, smoking status, history of asthma, COPD assessment test (CAT) score, post-bronchodilator (BD) FEV₁ % predicted, and diffusing capacity of carbon monoxide % predicted.

Results

K-means clustering identified four clusters for COPD that we named putative asthma-COPD overlap (ACO), mild COPD, moderate COPD, and severe COPD subtypes. The ACO group (n=196) showed the second-best post-BD FEV₁ (75.5% vs 80.9% [mild COPD, n=313] vs 52.4% [moderate COPD, n=345] vs 46.7% [severe COPD, n=341] predicted), the longest 6-min walking distance (424 m vs 405 m vs 389  m vs 365 m), and the lowest CAT score (12.2 vs 13.7 vs 15.6 vs 17.5) among the four groups. ACO group had greater risk for first AE compared to the mild COPD group (HR, 1.683; 95% CI, 1.175–2.410). The moderate COPD and severe COPD group HR values were 1.587 (95% CI, 1.145–2.200) and 1.664 (95% CI, 1.203–2.302), respectively. In addition, St. George’s Respiratory Questionnaire score (HR: 1.019; 95% CI, 1.014–1.024) and gastroesophageal reflux disease were independent factors associated with the first AE (HR: 1.535; 95% CI, 1.116–2.112).

Conclusion

Our cluster analysis revealed an exacerbator subtype of COPD independent of FEV₁. Since these patients are susceptible to AE, a more aggressive treatment strategy is needed in these patients.

Detection of pepsin and IL-8 in saliva of adult asthmatic patients

Objective: Asthma and gastric reflux disease are widespread and often coexisting diseases with complex interactions, leading some to suspect that asthma symptoms of patients with reflux may improve with anti-reflux therapy. The objective of this study was to determine whether pepsin in saliva, indicative of airway reflux, could be detected in patients with asthma of varying severity and test the requirement of citric acid as a pepsin preservative. Methods: Saliva samples were collected in the clinic (with/without citric acid) and upon waking the following morning from 25 asthmatic patients. Enzyme-linked immunosorbent assay was performed for pepsin and interleukin-8 (IL-8), an inflammatory cytokine induced by pepsin in other airway epithelia. Pepsin induction of IL-8 was tested in a lung epithelial cell culture model. Results: Pepsin was detected in saliva from 14/25 patients (56%; mean concentration of pepsin in specimens where observed ±SD =80.3±87.5 ng/mL); significant agreement was found between samples collected in the presence/absence of citric acid. No significant associations were found with pepsin and clinical measures of asthma severity. IL-8 was detected in saliva from 22/25 patients (88%; mean IL-8 in all specimens where observed =3.27±3.91 ng/mL). IL-8 was significantly upregulated in human lung epithelial cells exposed to pepsin at pH7 in vitro (P=0.041). Conclusion: In summary, more than half of the asthma patients in this study were found to have pepsin in their saliva, indicative of airway reflux. These data support the use of salivary pepsin as a noninvasive tool for future investigation of airway reflux in a larger cohort. The data further suggest that collection in citric acid as a sample preservative is not warranted and that pooling of multiple saliva samples collected at various timepoints may improve sensitivity of pepsin detection and reduce costs incurred by multiple sample analysis in future studies.

Revised (2018) COPD Clinical Practice Guideline of the Korean Academy of Tuberculosis and Respiratory Disease: A Summary

Chronic obstructive pulmonary disease (COPD) results in high morbidity and mortality among patients nationally and globally. The Korean clinical practice guideline for COPD was revised in 2018. The guideline was drafted by the members of the Korean Academy of Tuberculosis and Respiratory Diseases as well as the participating members of the Health Insurance Review and Assessment Service, Korean Physicians' Association, and Korea Respiration Trouble Association. The revised guideline encompasses a wide range of topics, including the epidemiology, diagnosis, assessment, monitoring, management, exacerbation, and comorbidities of COPD in Korea. We performed systematic reviews assisted by an expert in meta-analysis to draft a guideline on COPD management. We expect this guideline to facilitate the treatment of patients with respiratory conditions by physicians as well other health care professionals and government personnel in South Korea.

Rate control and clinical outcomes in patients with atrial fibrillation and obstructive lung disease

BACKGROUND

Rate-control medications are considered first-line treatment for patients with atrial fibrillation (AF). However, obstructive lung disease (OLD), a condition prevalent in those with AF, often makes it difficult to use those medications because of the lack of studies on new-onset AF in patients with OLD.

OBJECTIVE

The purpose of this study was to investigate clinical outcomes after administration of each class of rate-control medication in patients with concomitant AF and OLD (AF-OLD).

METHODS

This study used the entire database provided by the National Health Insurance Service from 2002 to 2015. Risk of all-cause mortality was compared between use of calcium channel blocker (CCB) and use of other drug classes in AF-OLD patients using Cox regression analyses after propensity score matching.

RESULTS

Among the 13,111 patients, the number of AF-OLD patients treated with a CCB, cardioselective β-blocker (BB), nonselective BB, and digoxin was 2482, 2379, 2255, and 5995, respectively. The risk of mortality was lower with use of selective BB (hazard ratio [HR] 0.84; 95% confidence interval [CI] 0.75-0.94; P = .002) and nonselective BB (HR 0.85; 95% CI 0.77-0.95; P = .003) compared to use of CCBs. Digoxin use was related with worse survival, with marginal statistical significance (HR 1.09; 95% CI 1.00-1.18; P = .053).

CONCLUSION

Among patients with AF-OLD, rate-control treatment using selective and nonselective BB was associated with a significant reduction in mortality compared with CCB use. Further prospective randomized trials are required to confirm these findings.

Assessment of anti-reflux treatment on pulmonary ventilation function and inflammatory cytokines in patients with stable chronic obstructive pulmonary disease combined with gastroesophageal reflux

Compelling evidence has demonstrated that systemic inflammation among patients with stable chronic obstructive pulmonary disease (COPD) is linked with increased levels of inflammatory cytokines. The aim of the present study was to investigate the effects associated with anti-reflux treatment on pulmonary ventilation function and inflammatory cytokines in patients with stable COPD and gastroesophageal reflux (GER). One hundred and thirty-six stable COPD and GER patients were recruited for the study and randomly designated into the routine treatment and the anti GER groups. Six months prior to and after treatment, pulmonary ventilation function, 6-min walk distance (6MWD) and times of acute exacerbation of COPD (AECOPD) were recorded. The levels of inflammatory cytokines IL-13, IL-18, transforming growth factor-β1 (TGF-βl) and tumor necrosis factor-α (TNF-α) in the sputum were detected by ELISA. BODE indexes, including body mass index, obstruction, dyspnea and exercise, were analyzed in order to evaluate patient prognoses. In comparison with the routine treatment group, patients in the anti-GER group displayed improved pulmonary ventilation function, increased 6MWD as well as decreases in AECOPD, levels of IL-13, IL-18, TGF-βl and TNF-α in the sputum and BODE index 6 months after treatment. The results obtained suggested a correlation between the BODE indexes after treatment and the course of disease as well as the frequency of exacerbation. The key findings of the study suggested that conventional treatment combined with anti-reflux treatment could effectively improve pulmonary ventilation function, while acting to decrease the levels of inflammatory cytokines and improve the prognosis of patients with stable COPD along with GER.

Hemoglobin and mortality in patients with COPD: a nationwide population-based cohort study

Purpose

Previous studies have reported that anemia increased mortality in patients with COPD. However, it is unclear whether anemia is associated with increased COPD mortality in the general population. The purpose of our study is to identify whether anemia is related to long-term mortality in COPD using a large population-based database.

Patients and methods

Using the National Health Insurance Service-Health Screening Cohort, we identified COPD patients with available hemoglobin level. We analyzed mortality among patients with COPD from 2003 to 2013 according to hemoglobin level.

Results

A total of 7,114 patients with COPD were identified. Mean age was 65.0±9.3 years, and 62.9% were male. Anemia was present in 469 patients (6.6%). The overall mortality rate was 46.5% in anemia and 32.1% in non-anemia groups (p<0.001). The hazard ratio of anemia for mortality was 1.31 (95% CI, 1.11–1.54). Among patients with anemia, the hemoglobin level correlated well with mortality.

Conclusion

Anemia was associated with increased long-term mortality of COPD, and even mild anemia was related to a significantly increased risk.

Heterogeneity of asthma and COPD overlap

Background

Asthma and COPD are heterogeneous diseases. Patients with both disease features (asthma-COPD overlap [ACO]) are common. However, clinical characteristics and socio-economic burden of ACO are still controversial. The aim of this study was to identify the heterogeneity of ACO and to find out the subtypes with clinical impact among ACO subtypes.

Methods

In the Korean National Health and Nutrition Examination Survey (KNHANES) conducted between 2007 and 2012, subjects who were ≥40 years and had prebronchodilator FEV₁/FVC <0.7 and FEV₁ ≥50% predicted were included. The presence or absence of self-reported wheezing was indicated by W+ or W- and used as an index of airway hyper-responsiveness. S+/S- was defined as subjects who were smokers/never smokers. The subjects were divided into the following four groups: W-S-, W-S+, W+S-, and W+S+. W+S- and W+S+ were asthma-predominant ACO and COPD-predominant ACO, respectively. KNHANES and linked National Health Insurance data were analyzed.

Results

The asthma-predominant ACO group showed the lowest socioeconomic status, FEV₁, FVC% predicted, and quality of life (QoL) levels. The COPD-predominant ACO group showed the highest hospitalization rate, outpatient medical cost, and total and outpatient health care utilization. COPD-predominant ACO was associated with exacerbations compared to the W-S- group (adjusted odds ratio [aOR], 1.79; 95% confidence interval [CI], 1.12-2.85; P=0.015) and W-S+ group (OR 2.11; 95% CI 1.43-3.10; P<0.001). COPD-predominant ACO was associated with increased medical cost.

Conclusion

Asthma-predominant ACO individuals displayed poorer socioeconomic status and QoL compared to the COPD-predominant ACO group. The COPD-predominant ACO group displayed more frequent exacerbations and greater medical costs. Considering the heterogeneity of ACO, it is desirable to identify subtypes of ACO patients and appropriately allocate limited medical resources.

Gastroesophageal Reflux and Idiopathic Pulmonary Fibrosis

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a progressive interstitial lung disease of unknown origin that affects about 40,000 new patients every year in the USA. Albeit the disease is labelled as idiopathic, it is thought that pathologic reflux, often silent, plays a role in its pathogenesis through a process of microaspiration of gastric contents.

AIMS

The aim of this study was to review the available evidence linking reflux to IPF, and to study the effect of medical and surgical therapy on the natural history of this disease.

RESULTS

Medical therapy with acid-reducing medications controls the production of acid and has some benefit. However, reflux and aspiraion of weakly acidic or alkaline gastric contents can still occur. Better results have been reported after laparoscopic anti-reflux surgery, as this form of therapy re-establishes the competence of the lower esophageal sphincter, therefore stopping any type of reflux.

CONCLUSIONS

A phase II NIH study in currently in progress in the USA to determine the role of antireflux surgery in patients with GERD and IPF. The hope is that this simple operations might alter the natural history of IPF, avoiding progression and the need for lung transplantation.

Examining patterns of multimorbidity, polypharmacy and risk of adverse drug reactions in chronic obstructive pulmonary disease: a cross-sectional UK Biobank study

OBJECTIVE

This study aims: (1) to describe the pattern and extent of multimorbidity and polypharmacy in UK Biobank participants with chronic obstructive pulmonary disease (COPD) and (2) to identify which comorbidities are associated with increased risk of adverse drug reactions (ADRs) resulting from polypharmacy.

DESIGN

Cross-sectional.

SETTING

Community cohort.

PARTICIPANTS

UK Biobank participants comparing self-reported COPD (n=8317) with no COPD (n=494 323).

OUTCOMES

Multimorbidity (≥4 conditions) and polypharmacy (≥5 medications) in participants with COPD versus those without. Risk of ADRs (taking ≥3 medications associated with falls, constipation, urinary retention, central nervous system (CNS) depression, bleeding or renal injury) in relation to the presence of COPD and individual comorbidities.

RESULTS

Multimorbidity was more common in participants with COPD than those without (17% vs 4%). Polypharmacy was highly prevalent (52% with COPD taking ≥5 medications vs 18% in those without COPD). Adjusting for age, sex and socioeconomic status, those with COPD were significantly more likely than those without to be prescribed ≥3 medications contributing to falls (OR 2.27, 95% CI 2.13 to 2.42), constipation (OR 3.42, 95% CI 3.10 to 3.77), urinary retention (OR 3.38, 95% CI 2.94 to 3.87), CNS depression (OR 3.75, 95% CI 3.31 to 4.25), bleeding (OR 4.61, 95% CI 3.35 to 6.19) and renal injury (OR 2.22, 95% CI 1.86 to 2.62). Concomitant cardiovascular disease was associated with the greatest risk of taking ≥3 medications associated with falls/renal injury. Concomitant mental health conditions were most strongly associated with medications linked with CNS depression/urinary retention/bleeding.

CONCLUSIONS

Multimorbidity is common in COPD and associated with high levels of polypharmacy. Co-prescription of drugs with various ADRs is common. Future research should examine the effects on healthcare outcomes of co-prescribing multiple drugs with similar potential ADRs. Clinical guidelines should emphasise assessment of multimorbidity and ADR risk.

Chronic Obstructive Pulmonary Disease Exacerbations Are Influenced by Gastroesophageal Reflux Disease

Gastroesophageal reflux disease (GERD) is associated with different pulmonary diseases, including chronic obstructive pulmonary disease (COPD). Whether GERD is contributory to COPD severity remains unclear. This study aims to evaluate the contribution of GERD to the clinical manifestation of COPD based on ventilatory parameters and yearly clinical exacerbations. We studied 48 patients (56% females, age 66 years) with COPD. All patients underwent high-resolution manometry and esophageal pH monitoring. The patients were separated into two groups according to the presence of GERD. GERD was present in 21 (44%) patients. GERD + and GERD – groups did not differ in regard to gender, age, and body mass index. Pulmonary parameters were not different in the absence or presence of GERD. The number of yearly exacerbations was higher in patients GERD1. The severity of GERD (as measured by DeMeester score) correlated with the number of exacerbations. Our results show the following: 1) GERD does not influence pulmonary parameters and 2) GERD is associated with a higher number of annual clinical exacerbations. We believe GERD must be objectively tested in patients with COPD because the prevalence of GERD in these patients is underestimated when only symptoms are considered. GERD treatment might decrease the frequency of episodes of exacerbation.

Review article: gastro-oesophageal reflux disease in asthma and chronic obstructive pulmonary disease

BACKGROUND

When gastro-oesophageal reflux is causing symptoms or lesions in the oesophagus, this is referred to as gastro-oesophageal reflux disease (GERD). GERD can manifest itself through typical symptoms (heartburn, regurgitation) or may lead to extra-oesophageal symptoms. Extra-oesophageal manifestations of GERD gained increasing attention over the last decade, especially respiratory disorders, because of the prevalent co-occurrence with GERD. The role of GERD in the pathogenesis of respiratory disorders has become a topic of intense discussion.

AIM

To provide an overview of the current knowledge on the role of GERD in asthma and chronic obstructive pulmonary disease (COPD).

METHODS

PubMed was searched for relevant articles using the keywords: GERD, asthma, COPD, prevalence, treatment. Case reports were excluded, only English language articles were considered.

RESULTS

Estimates for the prevalence of GERD in asthma range from 30% to 90%, compared to an average of 24% in controls. In COPD patients, the prevalence of GERD ranges from 19% to 78% compared to an average of 18% in controls. These data indicate an increased prevalence of GERD in patients with asthma and COPD, although causality is not established and GERD treatment yielded inconsistent effects. Literature supports GERD as a risk factor for COPD-exacerbations and a predictor of the 'frequent-exacerbator'-phenotype.

CONCLUSIONS

Despite the high prevalence of GERD in asthma and COPD, a causal link is lacking. The results of anti-reflux therapy on pulmonary outcome are inconsistent and contradictory. Future studies will need to identify subgroups of asthmatics and COPD patients that may benefit from anti-reflux therapy (nocturnal or silent reflux).

Impact and prevention of severe exacerbations of COPD: a review of the evidence

Severe exacerbations of COPD, ie, those leading to hospitalization, have profound clinical implications for patients and significant economic consequences for society. The prevalence and burden of severe COPD exacerbations remain high, despite recognition of the importance of exacerbation prevention and the availability of new treatment options. Severe COPD exacerbations are associated with high mortality, have negative impact on quality of life, are linked to cardiovascular complications, and are a significant burden on the health-care system. This review identified risk factors that contribute to the development of severe exacerbations, treatment options (bronchodilators, antibiotics, corticosteroids [CSs], oxygen therapy, and ventilator support) to manage severe exacerbations, and strategies to prevent readmission to hospital. Risk factors that are amenable to change have been highlighted. A number of bronchodilators have demonstrated successful reduction in risk of severe exacerbations, including long-acting muscarinic antagonist or long-acting β2-agonist mono- or combination therapies, in addition to vaccination, mucolytic and antibiotic therapy, and nonpharmacological interventions, such as pulmonary rehabilitation. Recognition of the importance of severe exacerbations is an essential step in improving outcomes for patients with COPD. Evidence-based approaches to prevent and manage severe exacerbations should be implemented as part of targeted strategies for disease management.

Summary of the Chronic Obstructive Pulmonary Disease Clinical Practice Guideline Revised in 2014 by the Korean Academy of Tuberculosis and Respiratory Disease

Chronic obstructive pulmonary disease (COPD) results in high morbidity and mortality among patients both domestically and globally. The Korean clinical practice guideline for COPD was revised in 2014. It was drafted by the members of the Korean Academy of Tuberculosis and Respiratory Diseases, as well as participating members of the Health Insurance Review and Assessment Service, Korean Physicians' Association, and Korea Respiration Trouble Association. This revised guideline covers a wide range of topics, including the epidemiology, diagnosis, assessment, monitoring, management, exacerbation, and comorbidities of COPD in Korea. We drafted a guideline on COPD management by performing systematic reviews on the topic of management with the help of a meta-analysis expert. We expect this guideline will be helpful medical doctors treating patients with respiratory conditions, other health care professionals, and government personnel in South Korea.

Idiopathic Pulmonary Fibrosis: Novel Concepts of Proton Pump Inhibitors as Antifibrotic Drugs

The prevalence of abnormal acid gastroesophageal reflux (GER) is higher in patients with idiopathic pulmonary fibrosis (IPF) than in matched control subjects. Several studies demonstrated that more than one-third of patients with IPF have abnormal esophageal acid exposures. In addition, many of these studies indicate that the majority of patients with IPF have silent reflux with no symptoms of GER. Findings of abnormal reflux persist in a large proportion of patients with IPF placed on antacid therapy such as proton pump inhibitors (PPIs). This seemingly paradoxical observation suggests that either patients with IPF are somehow resistant to PPI-based intervention or PPIs are inherently unable to suppress acid GER. By contrast, patients with IPF who undergo Nissen fundoplication surgery are effectively relieved from the complications of GER, and retrospective studies suggest improved lung function. Retrospective, anecdotal data suggest a beneficial role of PPIs in IPF including stabilization of lung function, reduction in episodes of acute exacerbation, and enhanced longevity. The recent evidence-based guidelines for treatment of IPF approved conditional recommendation of PPIs for all patients with IPF regardless of their GER status. Recently, we have reported that PPIs possess antiinflammatory and antifibrotic activities by directly suppressing proinflammatory cytokines, profibrotic proteins, and proliferation of lung fibroblasts. Our study provides an alternative explanation for the beneficial effect of PPIs in IPF. In this Perspective, we reviewed emerging progress on antifibrotic effect of PPIs using IPF as a disease model. In addition, we summarized surgical and pharmacological interventions for GER and their downstream effect on lung physiology.

Towards Actualizing the Value Potential of Korea Health Insurance Review and Assessment (HIRA) Data as a Resource for Health Research: Strengths, Limitations, Applications, and Strategies for Optimal Use of HIRA Data

Health Insurance and Review Assessment (HIRA) in South Korea, also called National Health Insurance (NHI) data, is a repository of claims data collected in the process of reimbursing healthcare providers. Under the universal coverage system, having fee-for-services covering all citizens in South Korea, HIRA contains comprehensive and rich information pertaining to healthcare services such as treatments, pharmaceuticals, procedures, and diagnoses for almost 50 million beneficiaries. This corpus of HIRA data, which constitutes a large repository of data in the healthcare sector, has enormous potential to create value in several ways: enhancing the efficiency of the healthcare delivery system without compromising quality of care; adding supporting evidence for a given intervention; and providing the information needed to prevent (or monitor) adverse events. In order to actualize this potential, HIRA data need to actively be utilized for research. Thus understanding this data would greatly enhance this potential. We introduce HIRA data as an important source for health research and provide guidelines for researchers who are currently utilizing HIRA, or interested in doing so, to answer their research questions. We present the characteristics and structure of HIRA data. We discuss strengths and limitations that should be considered in conducting research with HIRA data and suggest strategies for optimal utilization of HIRA data by reviewing published research using HIRA data.