High prevalence of current asthma and active smoking effect among the elderly

Work-related asthma in adults with severe asthma from the Korean Severe Asthma Registry (KoSAR)

Background

Exposure to allergens or irritants in the workplace may affect asthma control and the quality of life (QoL) of patients with asthma.

Objective

To examine the prevalence and characteristics of work-related asthma (WRA) in adult patients with severe asthma.

Methods

We analyzed data from the Korean Severe Asthma Registry (KoSAR), which is a nationwide multicenter observational study on severe asthma in Korea. Severe asthma was defined according to the American Thoracic Society (ATS) and the European Respiratory Society (ERS) guidelines. WRA was identified on the basis of asthma symptom aggravation at the workplace, as indicated by responses to a structured questionnaire. We compared the demographic and clinical characteristics and QoL between adult patients with severe asthma and WRA and those without WRA.

Results

Among 364 patients with severe asthma who were employed at the time of enrollment, 65 (17.9%) had WRA. There were no significant differences in age, sex, obesity, or smoking history between the WRA and non-WRA groups. However, individuals with WRA exhibited a higher prevalence of anxiety (7.7% vs 2.4%, P = 0.046) and depression (12.3% vs 3.7%, P = 0.010) than those without. The levels of asthma control, lung function, and frequency of asthma exacerbations were similar between the two groups, but patients with WRA reported lower QoL, as determined by the Quality of Life Questionnaire for Adult Korean Asthmatics (56.6 ± 14.6 vs. 63.5 ± 13.9, P < 0.001).

Conclusion

Patients with severe asthma and WRA are more likely to experience anxiety and depression and have lower QoL than those without WRA.

Increased blood eosinophils and airflow obstruction as new-onset asthma predictors in the elderly: The Nagahama study

BACKGROUND

Asthma in the elderly needs more attention in an aging society. However, it is likely to remain underdiagnosed and undertreated. This study aimed to clarify clinical characteristics of new-onset asthma in the elderly, describing the prevalence, predictive factors, and comorbidities after asthma diagnosis of new-onset asthma in the elderly in the general population.

METHODS

This community-based prospective cohort study enrolled 9804 generally healthy participants (30-74 years old) in Nagahama City, and conducted a follow-up assessment after 5 years. Elderly participants were those aged ≥65 years at baseline. Patients with new-onset asthma were defined as participants without asthma at baseline assessment and with asthma at the follow-up assessment.

RESULTS

Among the 7948 participants analyzed in this study, 28 (1.4%) elderly and 130 (2.2%) non-elderly had new-onset asthma. Multiple logistic regression analysis revealed low forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) and high blood eosinophil counts at baseline as predicting factors for new-onset asthma in the elderly. Additionally, subsequent incidence of new-onset asthma was higher in elderly participants with both predictors (high blood eosinophil counts and low FEV1/FVC at baseline) than those with none or one of the predictors before asthma diagnosis. Lastly, elderly patients with new-onset asthma had more frequent comorbidity of moderate to severe sleep disordered breathing than those non-elderly.

CONCLUSIONS

Eosinophilic inflammation and airflow obstruction may predict subsequent new-onset asthma after the age of 65 years. Revealing the characteristics of new-onset asthma in the elderly can aid in the prevention of underdiagnosed asthma.

Evaluation of short-acting Beta-2-agonist prescriptions and associated clinical outcomes: Findings from the SABA use IN Asthma (SABINA) study in Asia

Background

The extent of short-acting Beta-2-agonist (β2-agonist) (SABA) use across Asian countries is not well documented. As part of the SABA use IN Asthma (SABINA) III study, we assessed SABA prescriptions and clinical outcomes in patients with asthma from Asia.

Methods

This cross-sectional study recruited patients (aged ≥12 years) with asthma from 8 Asian countries. Data on disease characteristics and asthma treatments were collected using electronic case report forms. Patients were classified by practice type (primary or specialist care) and investigator-defined asthma severity (per Global Initiative for Asthma [GINA] 2017 recommendations). The association of SABA prescriptions with clinical outcomes was analyzed using multivariable regression models.

Results

Overall, 3066 patients were analyzed, with a mean (standard deviation) age of 51.8 (16.7) years; of these patients, 2116 (69%) were female, 2517 (82.1%) had moderate-to-severe asthma and 2498 (81.5%) and 559 (18.2%) were treated in specialist and primary care, respectively. In total, 1423 (46.4%) patients had partly controlled/uncontrolled asthma, with 1149 (37.5%) patients experiencing ≥1 severe asthma exacerbation in the previous year. Overall, 800 (26.7%) patients were prescribed ≥3 SABA canisters in the previous year, which is regarded as overprescription and was associated with a significantly decreased odds of at least partly controlled asthma and increased incidence rates of severe exacerbations (P < 0.01 for both associations).

Conclusion

The findings from this cohort of predominantly specialist-treated patients with asthma indicate SABA overprescription in at least 1 in every 4 patients, and this overprescription is associated with poor clinical outcomes. These data highlight the need for adherence to recently updated asthma treatment recommendations in Asia.

The Impact of Tobacco Cigarettes, Vaping Products and Tobacco Heating Products on Oxidative Stress

Cells constantly produce oxidizing species because of their metabolic activity, which is counteracted by the continuous production of antioxidant species to maintain the homeostasis of the redox balance. A deviation from the metabolic steady state leads to a condition of oxidative stress. The source of oxidative species can be endogenous or exogenous. A major exogenous source of these species is tobacco smoking. Oxidative damage can be induced in cells by chemical species contained in smoke through the generation of pro-inflammatory compounds and the modulation of intracellular pro-inflammatory pathways, resulting in a pathological condition. Cessation of smoking reduces the morbidity and mortality associated with cigarette use. Next-generation products (NGPs), as alternatives to combustible cigarettes, such as electronic cigarettes (e-cig) and tobacco heating products (THPs), have been proposed as a harm reduction strategy to reduce the deleterious impacts of cigarette smoking. In this review, we examine the impact of tobacco smoke and MRPs on oxidative stress in different pathologies, including respiratory and cardiovascular diseases and tumors. The impact of tobacco cigarette smoke on oxidative stress signaling in human health is well established, whereas the safety profile of MRPs seems to be higher than tobacco cigarettes, but further, well-conceived, studies are needed to better understand the oxidative effects of these products with long-term exposure.

Prevalence of and risk factors for asthma among people aged 45 and older in China: a cross-sectional study

Background

Asthma is one of the most prevalent chronic respiratory diseases worldwide. This study aimed to determine the updated prevalence of and risk factors for asthma among individuals aged 45 and older in mainland China.

Methods

The data for this study came from the fourth wave of the China Health and Retirement Longitudinal Study (CHARLS) conducted by the National School of Development of Peking University in 2018. The CHARLS is a nationally representative survey targeting populations aged 45 and over from 28 provinces/cities in mainland China. A representative sample of 19,816 participants was recruited for the study using a multistage stratified sampling method. The prevalence of asthma was determined across different characteristics. The potential risk factors were examined by multivariable logistic regressions.

Results

A total of 18,395 participants (8744 men and 9651 women) were eligible for the final data analysis. The estimated prevalence of asthma among Chinese people aged ≥ 45 years in 2018 was 2.16% (95% CI 1.96–2.38). The prevalence of asthma significantly differed according to race (P = 0.002), with an overall rate of 2.07% (95% CI 1.86–2.29) in Han paticipants and 3.32% (95% CI 2.50–4.38) in minority participants. Furthermore, the minority ethnicities (OR = 1.55 [95% CI 1.12–2.14], P = 0.008), older age (60–69 years group: OR = 1.85 [95% CI 1.17–2.92], P = 0.008; ≥ 70 years group: OR = 2.63 [95% CI 1.66–4.17], P < 0.001), an education level of middle school or below (middle-school education: OR = 1.88 [95% CI 1.15–3.05], P = 0.011; primary education: OR = 2.48 [95% CI 1.55–3.98], P < 0.001; literate: OR = 2.53 [95% Cl 1.57–4.07], P < 0.001; illiterate: OR = 2.78 [95% CI 1.72–4.49, P < 0.001]), smoking (OR = 1.37 [95% CI 1.11–1.68], P = 0.003), and residence in North (OR = 1.52 [95% CI 1.11–2.09], P = 0.01) or Northwest China (OR = 1.71 [95% CI 1.18–2.49], P = 0.005) were associated with prevalent asthma.

Conclusions

Asthma is prevalent but underappreciated among middle-aged and elderly people in China. A number of risk factors were identified. These results can help to formulate correct prevention and treatment measures for asthma patients.

Particulate matter exposure is highly correlated to pediatric asthma exacerbation

Asthma is a heterogeneous disease in which environmental factors play an important role, and the effect of particulate matter (PM) on the occurrence and severity of asthma is drawing more attention. This study aims to identify the correlation between PM and pediatric asthma exacerbation and explore the potential mechanisms. The asthma visits data (N = 16,779,739) in a university-based tertiary children’s hospital from January 2013 to December 2017 were collected, and the relationship between asthma visits and local PM concentration was analyzed. For further study, we established a house dust mite (HDM)-induced allergic airway inflammation model with PM intervention. We detected a correlation between PM concentration and pediatric asthma visits, especially in children under 6 years old. The in vivo data showed that PM aggravated HDM-induced airway inflammation, and IL-33 neutralizing antibody exerted a protective role. Our study suggests that PM is a risk factor in promoting pediatric asthma exacerbation, in which IL-33 might be a promising target.

Socioeconomic-related determinants of asthma in the elderly

Introduction

As the population ages, the impact of asthma in the elderly is expected to be enhanced over the forthcoming decades. We investigated the prevalence of asthma and its socioeconomic factors in the elderly, Shiraz, Iran.

Methods

In this population-based study, 1527 subjects older than 60 years were selected based on the stratified random sampling method. The data on asthma symptoms, current asthma, physician diagnose asthma, and allergic rhinitis were collected using the translated ECRHS (European Community Respiratory Health Survey) questionnaire. Information on individual socioeconomic status was derived from the participants' self-reported educational level and their occupation, income, and residence. A p-value of less than 0.05 was considered to be statistically significant.

Results

The prevalence of asthma, current asthma, physician diagnose asthma, and allergic rhinitis was found to be 8.97, 6.81, 4.78 and, 23.51%, respectively. The most common asthma symptoms were nocturnal chest tightness (15.52%, n = 237/1,527). In univariate analysis, the prevalence of asthma was higher in illiterate patients (12.7%), subjects with the lowest income level (10.6%), and patients living in urban areas (24.1%). Having age more than 80 (OR = 2.01; 95% CI = 1.10-3.65), being a current smoker (OR = 2.76; 95% CI = 1.69-4.51) and living in a suburban area (OR = 3.01; 95% CI = 1.20-7.50) were significant predictive factors for asthma in the regression model.

Conclusions

Asthma and allergic rhinitis in the elderly should be more focus in the southwest of Iran. Moreover, our findings highlighted the effect of socio- economic status, disparities and inequality on community health.

Effects of long-standing exposure to heavy-duty diesel vehicle traffic on respiratory symptoms and airway inflammation in older adults

In the present study, we evaluated the effects of chronic exposure to traffic from a heavy-duty diesel-fueled vehicle area on respiratory symptoms and airway inflammation in a nonsmoking adult and elderly population. Respiratory symptoms were evaluated by the ISAAC questionnaire (International Study of Asthma and Allergies questionnaire), and airway inflammation was assessed by fractional exhaled nitric oxide (FeNO). Forty volunteers were selected from the 112 volunteers who completed the ISAAC questionnaire for the measurement of FeNO. The FeNO population comprised seven men (six aged ≥ 64 years old, four aged ≥ 75 years old) and 32 women (27 aged ≥ 64 years old, nine aged ≥ 75 years old). FeNO levels were tracked for six months, from November 2014 to June 2015. Results: Twenty-four percent of the volunteers reported having had wheezing in the chest in the last 12 months. However, only 2.7% of the volunteers reported doctor-diagnosed asthma. There was a positive association between FeNO and pollutants in most of the study months. An increase of 1 μg m^-3 in NO₂ was associated with a mean increase of 1.08 ppb in FeNO, and an increase of 1 μg m_-3 in O₃ was associated with a mean increase of 1.06 ppb in FeNO. The relative risk for NO₂ ranged from 1.009 to 1.32 and that for O₃ ranged from 1.014 to 1.020. Conclusion: The frequency of respiratory symptoms was much higher than the previously described levels of 6% in the Brazilian adult population. In summary, a high frequency of respiratory symptoms and high levels of FeNO were described in an underdiagnosed adult population living very close to a heavy-duty diesel-traffic area. Older elderly adults presented greater susceptibility to airway inflammation than younger adults.

Are frailty and patient-reported outcomes independent in subjects with asthma? A cross-sectional observational study

INTRODUCTION

This study examined the possible associations between frailty and patient-reported outcomes (PROs) in elderly patients with asthma.

METHODS

Participants completed the Kihon Checklist for frailty screening as well as the following tools for measuring generic- and disease-specific health-related quality of life (HRQOL) and asthma control; the Medical Outcomes Study 36-item short form (SF-36), the Hyland Scale (global scale), the Asthma Quality of Life Questionnaire (AQLQ), the Asthma Control Test (ACT), and the Asthma Control Questionnaire (ACQ).

RESULTS

Of 69 consecutive outpatients with asthma, 38 (55.1%), 21 (30.4%), and 10 (14.5%) were classified as robust, pre-frail, and frail, respectively. Eight out of 52 patients with asthma in the elderly (AIE) (>65 years old) (15.4%) were considered as being frail. The Kihon Checklist total score was significantly correlated with all the scores obtained from the SF-36, Hyland Scale, AQLQ, ACT, and ACQ. All these scores were significantly different between groups with and without frailty. From the viewpoint of correlation coefficient, SF-36 Physical Functioning correlated most strongly with a coefficient of -0.68 (P < .01), and the Hyland Scale score was second (R_S = -0.46, P < .01). The correlations between the Kihon Checklist total score and lung function parameters were weak or negative (|R_S | < 0.35).

DISCUSSION

There were significant associations between frailty and PROs, particularly generic perception of HRQOL. Since the Kihon Checklist and PROs such as the HRQOL overlap somewhat in their evaluation of the patients' condition, there might be some similarities in the conceptual frameworks of frailty and quality of life.

Randomized controlled trial of triple versus dual inhaler therapy on small airways in smoking asthmatics

BACKGROUND

Smoking worsens underlying asthma inflammation and also induces resistance to inhaled corticosteroids (ICS). Small airways dysfunction measured by impulse oscillometry (IOS) is associated with worse control.

OBJECTIVES

We investigated the effects on small airways of adding long-acting beta-agonist (LABA) alone or with long-acting muscarinic antagonist (LAMA) to ICS in asthmatic smokers.

METHODS

Sixteen current smokers were enrolled: mean age 44 year, FEV1 84%, FEF25-75 47%, R5 158%, ACQ 1.69, 20 pack year . Patients were converted to a reference ICS as HFA-BDP during initial run-in at median dose of 800 µg/day. Open label olodaterol 5 µg od (OLO) or olodaterol 5 µg/tiotropium 5 µg od (OLO/TIO) was added to HFA-BDP for median duration of 3 weeks in a randomized cross over design, including run-in and washout periods on HFA-BDP. IOS and spirometry were measured after each treatment (BDP/OLO/TIO or BDP/OLO) and at baseline after run-in and washout (BDP).

RESULTS

After chronic dosing, IOS outcomes at trough except for R20 were all significantly improved with OLO/TIO compared to OLO. For the primary end-point of total airway resistance (as R5), the mean difference (95%CI) at trough was 0.06 (0.015-0.10) kPa/l/s, peripheral airways resistance (as R5-R20) 0.03 (0.003-0.06) kPa/l/s, peripheral lung reactance area (as AX) 0.38 (0.08-0.68) kPa/l and resonant frequency (as RF) 2.28 (0.45-4.12) Hz. FEF25-75 at trough was also better with OLO/TIO vs TIO: 0.93 (0.86 - 0.95) l/s while FEV1 was not different.

CONCLUSIONS

ICS/LABA/LAMA was superior to ICS/LABA on trough small airway outcomes in asthma patients who smoke.

Risk Factors for Acute Exacerbations in Elderly Asthma: What Makes Asthma in Older Adults Distinctive?

Purpose

Asthma in the elderly (EA; ≥ 65 years of age) is increasing, adding a heavy socioeconomic burden to the healthcare system. However, little is known about risk factors associated with acute exacerbations in EA patients. The objective of this study was to investigate risk factors for acute exacerbation in EA compared to non-elderly asthma (NEA).

Methods

We combined data from 3 adult asthma cohorts under a unified protocol and database. Asthmatic patients with regular follow-up during a 1-year period were selected from the cohorts to identify the risk factors predicting acute exacerbations in EA compared to NEA.

Results

We selected a total of 1,086 patients from the merged cohort. During the observation period, 503 and 583 patients were assigned to the EA and NEA groups, respectively. The exacerbation rate was 31.0% in the EA and 33.2% in the NEA group. Multivariate logistic regression analysis revealed fixed airway obstruction, chronic rhinosinusitis (CRS), and male sex as independent risk factors for exacerbation in the EA group. In the NEA group, exacerbation increased along with an increase in eosinophil count. Bayesian analysis of the interactions among clinical factors revealed that forced expiratory volume in 1 second/forced vital capacity was directly related to exacerbation in the EA group, and eosinophil count was related to exacerbation in the NEA group.

Conclusions

We suggest that fixed airway obstruction and CRS as the important clinical factors predicting acute exacerbations in EA, whereas in NEA, eosinophil count was the strong predictor of exacerbation.

Increasing Prevalence and Mortality of Asthma With Age in Korea, 2002-2015: A Nationwide, Population-Based Study

Purpose

The prevalence of asthma is increasing globally as the world population increases; however, and the prevalence and mortality of asthma have not been extensively investigated. Also, the effects of severity and aging on asthma prevalence and mortality are unknown. We aimed to investigate trends of the prevalence and mortality of asthma as well as health care uses and costs over 14 years according to disease severity by using real-world data in Korea.

Methods

Using the National Health Insurance Sharing Service database, we extracted asthmatic patients having diagnosis codes of asthma and prescription records of antiasthmatic medications from 2002 to 2015 and categorized them according to asthma exacerbation and regular treatment. We defined asthma-associated death in terms of patients' prescription records within 3 months before all-cause death, then linked with the Cause of Death Statistics. The annual asthma-related health care uses and costs were analyzed.

Results

The prevalence rates of asthma (1.6% to 2.2%) and severe asthma (SA; 3.5% to 6.1% among total asthmatics) have increased steadily over the decade in Korea, where the proportion of elderly asthmatics having increased. The asthma-related health care uses and costs had increased during the study period with the highest uses/costs in SA. The asthma mortality had a steady rising trend from 16.2 to 28.0 deaths per 100,000 with the highest mortality in SA.

Conclusions

The prevalence and mortality of asthma as well as SA increases along with the burden of health care uses/costs. More active interventions, including changes in health care policies, are needed to reduce the prevalence and mortality of asthma, especially SA.

Prevalence, risk factors, and management of asthma in China: a national cross-sectional study

BACKGROUND

Asthma is a common chronic airway disease worldwide. Despite its large population size, China has had no comprehensive study of the national prevalence, risk factors, and management of asthma. We therefore aimed to estimate the national prevalence of asthma in a representative sample of the Chinese population.

METHODS

A representative sample of 57 779 adults aged 20 years or older was recruited for the national cross-sectional China Pulmonary Health (CPH) study using a multi-stage stratified sampling method with parameters derived from the 2010 census. Ten Chinese provinces, representative of all socioeconomic settings, from six geographical regions were selected, and all assessments were done in local health centres. Exclusion criteria were temporary residence, inability to take a spirometry test, hospital treatment of cardiovascular conditions or tuberculosis, and pregnancy and breastfeeding. Asthma was determined on the basis of a self-reported history of diagnosis by a physician or by wheezing symptoms in the preceding 12 months. All participants were assessed with a standard asthma questionnaire and were classed as having or not having airflow limitation through pulmonary function tests before and after the use of a bronchodilator (400 μg of salbutamol). Risk factors for asthma were examined by multivariable-adjusted analyses done in all participants for whom data on the variables of interest were available. Disease management was assessed by the self-reported history of physician diagnosis, treatments, and hospital visits in people with asthma.

FINDINGS

Between June 22, 2012, and May 25, 2015, 57 779 participants were recruited into the CPH study. 50 991 (21 446 men and 29 545 women) completed the questionnaire survey and had reliable post-bronchodilator pulmonary function test results and were thus included in the final analysis. The overall prevalence of asthma in our sample was 4·2% (95% CI 3·1-5·6), representing 45·7 million Chinese adults. The prevalence of asthma with airflow limitation was 1·1% (0·9-1·4), representing 13·1 million adults. Cigarette smoking (odds ratio [OR] 1·89, 95% CI 1·26-2·84; p=0·004), allergic rhinitis (3·06, 2·26-4·15; p<0·0001), childhood pneumonia or bronchitis (2·43, 1·44-4·10; p=0·002), parental history of respiratory disease (1·44, 1·02-2·04; p=0·040), and low education attainment (p=0·045) were associated with prevalent asthma. In 2032 people with asthma, only 28·8% (95% CI 19·7-40·0) reported ever being diagnosed by a physician, 23·4% (13·9-36·6) had a previous pulmonary function test, and 5·6% (3·1-9·9) had been treated with inhaled corticosteroids. Furthermore, 15·5% (11·4-20·8) people with asthma reported at least one emergency room visit and 7·2% (4·9-10·5) at least one hospital admission due to exacerbation of respiratory symptoms within the preceding year.

INTERPRETATION

Asthma is prevalent but largely undiagnosed and undertreated in China. It is crucial to increase the awareness of asthma and disseminate standardised treatment in clinical settings to reduce the disease burden.

FUNDING

National Key R&D Program of China, Ministry of Science and Technology of China; the Special Research Foundation for Public Welfare of Health, Ministry of Health of China; the Chinese National Research Program for Key Issues in Air Pollution Control; and the National Natural Science Foundation of China.

Association Between Epithelial Cytokines and Clinical Phenotypes of Elderly Asthma

Purpose

Asthma in the elderly has different clinical features including more severe phenotypes with higher comorbidities. Epithelial cells are known to initiate innate/adaptive immune responses in asthmatic airways. We investigated clinical features and epithelial derived cytokine levels in elderly asthmatics compared to non-elderly asthmatics in a cross-sectional cohort of adult asthmatics in order to further understand its pathogenic mechanisms.

Methods

A total of 1,452 adult asthmatics were enrolled from a single tertiary hospital and were classified into 2 groups: 234 elderly (≥ 60 years at initial diagnosis) and 1,218 non-elderly (< 60 years at initial diagnosis) asthmatics. Asthma-related clinical parameters were compared between the 2 groups. Serum levels of epithelial cell-derived cytokines including interleukin (IL)-31, IL-33, IL-8, eotaxin-2, transforming growth factor beta 1 (TGF-β1) and periostin were measured by enzyme-linked immunosorbent assay.

Results

Significantly higher prevalence rates of late-onset asthma (onset age ≥ 40 years) and severe asthma, as well as the lower rate of atopy, blood/sputum eosinophil counts, total immunoglobulin E and eosinophil cationic protein levels were noted in elderly asthmatics compared to non-elderly asthmatics (P < 0.05, respectively). The forced expiratory volume in 1 second (FEV1, % predicted) level tended to be lower in elderly asthmatics (P = 0.07). In addition, serum IL-33 and IL-31 levels were significantly lower in elderly asthmatics, while no differences were found in the serum level of IL-8, eotaxin-2, TGF-β1 or periostin. Among elderly asthmatics, subjects with severe asthma had lower FEV1 (% predicted) value, but showed significantly higher serum levels of eotaxin-2 and TGF-β1, than those with non-severe asthma (P < 0.05 for each).

Conclusions

These findings suggest that age-related changes of epithelial cell-derived cytokines may affect clinical phenotypes and severity of elderly asthma: decreased levels of IL-33 and IL-31 may contribute to less Th2 phenotype, while increased levels of eotaxin-2 and TGF-β1 may contribute to severity.

Asthma over the Adult Life Course: Gender and Hormonal Influences

Asthma is a common disorder that affects genders differently across the life span. Earlier in life, it is more common in boys. At puberty, asthma becomes more common and often more severe in girls and women. The effect of sex hormones on asthma incidence and its severity is difficult to differentiate from other asthma severity risk factors, such as racial background, socioeconomic factors, obesity, atopy, environmental exposure, and, in particular, lung aging. Recognizing gender-associated and age-associated differences is important to understanding the pathobiology of asthma and to providing effective education and personalized care for patients with asthma across the life course.

Changing patterns of adult asthma incidence: results from the National Health Insurance Service-National Sample Cohort (NHIS-NSC) database in Korea

This study was conducted to assess the changes in the annual incidence of adult asthma in Korea where the prevalence of asthma had increased steadily in recent decades. A population-based cohort study was conducted using the National Health Insurance Service–National Sample Cohort (NHIS-NSC), which consisted of 746,816 adults aged >20 years between 2004 and 2012. Asthma was defined by two or more physician claims on the basis of a primary diagnostic code for asthma and administration of asthma medications within 1 year. The incidence rates and annual percent change were calculated, and the influence of age and sex on the incidence rates was studied. The annual asthma incidence increased from 3.63 in 2004 to 6.07 per 1,000 person-years in 2008. Since 2008, the asthma incidence did not change significantly. The asthma incidence was higher in women than in men throughout the study periods (p < 0.001) and higher in older than younger age groups (p < 0.001). The asthma incidence did not change in all ages since 2008, except for the 20 s who showed a steady increase. The incidence of asthma in adults reached plateau in Korea, which is consistent with the results from studies in other countries.

Is aging a "comorbidity" of asthma?

The aging population is growing at an unparalleled rate. Asthma is common in the elderly (age over 65 years) and can be more severe with little chance for remission. Asthma in older individuals is often under-diagnosed, misdiagnosed and frequently under-treated. Concomitant medical and psychosocial conditions are more prevalent in the elderly and can obfuscate the presentation of asthma and make it more difficult to assess and manage. While these comorbidities are important in understanding elderly asthma, aging itself can be considered a "comorbidity" since it impacts structural and functional changes in the lung. Structural changes of the aging lung may worsen physiologic function in asthma. The immune system also changes with age, with increased vulnerability to pathogens and differences in airway inflammation, leading to variability in how asthma manifests and responds to treatment. The fact that aging can influence the severity and presentation of asthma along with its diagnosis and management is important for the treating physician to understand. This article will discuss the multitude of factors that justify considering aging as a comorbidity of asthma.

The relationship between metabolic syndrome and asthma in the elderly

The burden of asthma in the elderly is increasing, but the etiology of asthma in the elderly is not clearly understood. Recent studies have reported the epidemiological link between metabolic syndrome (MS) and asthma, but it has rarely been studied in the elderly. This study investigated the association between MS and asthma and the contribution of insulin resistance (IR) and systemic inflammation to this MS-asthma association in the elderly. Our study analyzed 4,060 elderly participants (≥65 years old) from a cross-sectional survey, the Korean National Health and Nutritional Examination Survey 2007–2012. Mediation analyses were performed to examine whether IR and systemic inflammation mediates the MS-asthma association. Participants with MS had significantly higher prevalence of asthma (adjusted odds ratio = 1.34; 95% confidence interval = 1.09–1.64), and those who had greater waist circumference and lower HDL-C were especially likely to have asthma. Participants with IR and systemic inflammation were associated with higher prevalence of asthma. Prevalence of IR and systemic inflammation were higher in participants with MS or with each MS component. The MS-asthma association was substantially mediated by IR and systemic inflammation. Our study showed a significant association between MS and asthma in the elderly. MS might affect asthma through both IR and systemic inflammation.

Age-related prevalence of chronic rhinosinusitis and nasal polyps and their relationships with asthma onset

BACKGROUND

Chronic rhinosinusitis (CRS) is a major disease condition with high morbidity and can influence lower airway disease status in adults. However, its associations with adult asthma onset and activity have not been examined in detail in a general adult population.

OBJECTIVE

To investigate relationships between CRS with nasal polyps (CRSwNP) and asthma characteristics.

METHODS

A cross-sectional data set of 17,506 adult participants (≥18 years old) in the Korean National Health and Nutrition Examination Survey from 2010 through 2012 was analyzed. CRS was defined using structured questionnaires according to the international guideline, and presence of nasal polyps was objectively assessed using nasal endoscopy. Presence of asthma and its onset and current activity were assessed using structured questionnaires.

RESULTS

CRS was significantly related to asthma, but the relationships were distinct by CRS and asthma status. CRSwNP was significantly associated with adult-onset asthma (onset after 18 years of age) or late-onset asthma (onset after 40 years of age), whereas CRS without nasal polyps was related to childhood-onset asthma (onset before 18 years) or early-onset asthma (onset before 40 years) in adults. The 2 CRS subgroups showed significant associations with current asthma but not with past asthma. However, the comorbid asthma rate was lower than 10% among subjects with CRS.

CONCLUSION

This study found distinct age-related patterns of CRSwNP and asthma and demonstrated their significant associations in a general population. However, the low prevalence of asthma in CRSwNP is in sharp contrast to findings in Western populations, which warrants further investigation for ethnic or regional differences in relationships between CRSwNP and asthma.

Late-onset asthma: current perspectives

Because the pathophysiology of asthma has diverse characteristics, to manage the disease effectively, it is important for clinicians to distinguish among the clinical phenotypes. Among them, adult-onset asthma, that is, late-onset asthma (LOA), is increasing because of the aging of the population. The phenotype of LOA is largely divided into two types according to the presence or absence of eosinophilic inflammation, T-helper (Th)2- and non-Th2-associated LOA. Especially in Th2 LOA related to rhinosinusitis, as pulmonary function at onset is poor and asthma exacerbations occur frequently, it is important to detect this phenotype in the early phase by using a biomarker of Th2-type inflammation such as fractional exhaled nitric oxide (FENO). As non-Th2-LOA is often resistant to corticosteroids, this phenotype often requires another treatment strategy such as macrolide, diet, or smoking cessation. We often struggle with the management of LOA patients due to a lack of evidence; therefore, the elucidation of the mechanism of LOA contributes to increased efficiency of diagnosis and treatment of LOA. Age-related immune system and structural changes are thought to be associated with the pathophysiology of LOA. In the former case, changes in inflammatory cell function such as variations in the innate immune response and acquisition of autoimmunity or upregulation of oxidative stress are thought to be involved in the mechanism. Meanwhile, the latter can also become triggers or exacerbating factors of LOA via enhancement of airway hyperresponsiveness, decline in lung function, increased air trapping, and reduction in chest wall compliance. Therefore, appropriate individualized management in LOA may be possible through precisely assessing the pathophysiology based on age-related functional changes, including the immune and structural system.

Asthma in the elderly and late-onset adult asthma

Elderly asthmatics are at a higher risk for morbidity and mortality from their asthma than younger patients. There are important age-related physiologic and immunologic changes that complicate the presentation, diagnosis, and management of asthma in the aged population. Evidence suggests that elderly asthmatics are more likely to be underdiagnosed and undertreated. Additionally, elderly patients with asthma have highest rates of morbidity and mortality from their disease than younger patients. The underlying airway inflammation of asthma in this age group likely differs from younger patients and is felt to be non-type 2 mediated. While elderly patients are underrepresented in clinical trials, subgroup analysis of large clinical trials suggests they may be less likely to respond to traditional asthma therapies (ie, corticosteroids). As the armamentarium of pharmacologic asthma therapies expands, it will be critical to include elderly asthmatics in large clinical trials so that therapy may be better tailored to this at-risk and growing population.

Time trends of the prevalence of allergic diseases in Korea: A systematic literature review

The prevalence of allergic diseases has increased dramatically in recent decades, and are now considered major chronic diseases at the global level. The increasing burden of allergic diseases has led to numerous worldwide and local researchers to investigate the time trends in its prevalence and identify its driving factors. Environmental changes such as urbanization and industrialization have been suggested to explain the increasing prevalence, but recent reports from Western countries suggest that this prevalence has reached a plateau or even possibly, started to decrease. However, such environmental changes are still occurring in many Asia-Pacific countries, including Korea, and it is speculated that the peak in allergy epidemics has yet to come. The present systematic literature review aimed to explore the time trends in the prevalence of allergic diseases in Korea and to identify the unmet needs for facilitating further studies.

Relationships between self-reported asthma and pulmonary function and various measures of obesity

OBJECTIVE

We explore the association with self-reported asthma and pulmonary function based on spirometry measurements using different measures to determine obesity because body mass index (BMI) is limited in not differentiating fat and muscle mass.

METHODS

A multi-year cross-sectional study using Korean National Health and Nutrition Examination Survey data was conducted between July 2008 and May 2011. A total of 9409 subjects were included in the final analysis.

RESULTS

Obesity was associated with self-reported asthma and pulmonary function limitations mainly in adult women aged between 40 and 65 years and elderly men aged 65 or older. The association was stronger when the measurement of obesity was based on body fat percentage or waist-to-height ratio (WHtR), compared to BMI. There was a higher self-reported asthma risk among obese women according to the WHtR [odds ratio (OR) = 1.817, 95% CI: (1.208, 2.735)]. There was an increased risk of pulmonary function limitation with abdominal obesity [OR 1.418, 95% CI (1.020, 1.972)], weight-to-height ratio [OR 1.467, 95% CI (1.058, 2.034)], and obesity with regard to body fat percentage [OR 1.753, 95% CI (1.251, 2.457)] in adult women. In elderly men, obesity based on body fat percentage was associated with an increased risk of pulmonary function limitation [OR 1.93, 95% CI (1.098, 3.388)].

CONCLUSIONS

Measures other than BMI should be examined when investigating the effect of obesity on self-reported asthma and pulmonary function limitation.

Patterns of Inhalant Allergen Sensitization and Geographical Variation in Korean Adults: A Multicenter Retrospective Study

Purpose

Inhalant allergen sensitization is one of the major factors involved in the pathogenesis of allergic respiratory diseases. However, the sensitization is determined by interactions between genetic and environmental factors. Thus, testing panels of inhalant allergens may differ among geographical areas. Here we aimed to determine 10 common inhalant allergens in Korean adult patients with suspected respiratory allergies and to examine the variation between different geographical locations.

Methods

A total of 28,954 patient records were retrieved for retrospective analysis, from 12 referral allergy clinics located in 9 different areas. Inclusion criteria were Korean adults (≥18 years old) who underwent the inhalant allergen skin prick test for suspected history of respiratory allergy. The primary outcome was inhalant allergen skin prick response. Demographic and clinical information were also collected. Positive skin prick responses to allergens were defined as allergen-to-histamine wheal ratio ≥1. Based on skin test results, the most prevalent aeroallergens were determined.

Results

The overall prevalence of allergic sensitization was 45.3%. Dermatophagoides farinae and Dermatophagoides pteronyssinus were the most commonly sensitized allergens. Other common inhalant allergens were cat epithelium (8.1%), birch (7.7%), mugwort (6.9%), alder (6.7%), hazel (6.7%), beech (6.7%), oak (6.6%), and Tyrophagus putres (6.2%), in decreasing order frequency. These 10 inhalant allergens explained 90% of inhalant allergen sensitization in the study participants. However, distinct patterns of the 10 inhalant sensitization were observed in patients living in Chungnam and Jeju. American cockroach, Gernam cockroach, and Trichophyton metagrophytes were unique in Chungnam. Orchard, Japanese cedar, and Velvet were unique in Jeju.

Conclusions

The present analysis suggests a panel of 10 most common inhalant allergens in Korean adult patients with suspected respiratory allergies, which explained 90% of inhalant allergen sensitization. This panel can be utilized as a practical and convenient tool for primary practice and epidemiological surveys of respiratory allergic diseases.

Staphylococcal enterotoxin IgE sensitization in late-onset severe eosinophilic asthma in the elderly

BACKGROUND

Asthma in the elderly (aged ≥ 65 years old) is a significant concern with high morbidity, but the pathophysiology remains unclear particularly in late-onset asthma. Recent studies suggest staphylococcal enterotoxin IgE (SE-IgE) sensitization to be a risk factor for asthma in general populations; however, the associations have not been examined in late-onset elderly asthma.

OBJECTIVE

We aimed to examine the associations of SE-IgE sensitization with late-onset asthma in the elderly, using a database of elderly asthma cohort study.

METHODS

A total of 249 elderly patients with asthma and 98 controls were analysed. At baseline, patients were assessed for demographics, atopy, induced sputum profiles and comorbidities including chronic rhinosinusitis (CRS). Serum total IgE and SE-IgE levels were measured. Asthma severity was assessed on the basis of asthma outcomes during a 12-month follow-up period.

RESULTS

At baseline, serum SE-IgE concentrations were significantly higher in patients with asthma than in controls [median 0.16 (interquartile range 0.04-0.53) vs. 0.10 (0.01-0.19), P < 0.001]. Elderly asthma patients with high SE-IgE levels had specific characteristics of having more severe asthma, sputum eosinophilia and CRS, compared to those with lower SE-IgE levels. In multivariate logistic regression analyses, the associations between serum SE-IgE concentrations and severe asthma were significant, independently of covariables [SE-IgE-high (≥ 0.35 kU/L) vs. negative (< 0.10 kU/L) group: odds ratio 7.47, 95% confidence interval 1.86-30.03, P = 0.005]. Multiple correspondence analyses also showed that high serum SE-IgE level had close relationships with severe asthma, CRS and sputum eosinophilia together.

CONCLUSIONS AND CLINICAL RELEVANCE

This is the first report on the significant associations of SE-IgE sensitization with late-onset asthma in the elderly, particularly severe eosinophilic asthma with CRS comorbidity. Our findings indicate a potential implication of SE in the high morbidity burden of elderly asthma and suggest clues to the pathogenesis of severe late-onset eosinophilic asthma in the elderly.

Effect of aging on sputum inflammation and asthma control

BACKGROUND

Aged asthmatic patients experience increased morbidity and mortality. Knowledge of the aging effect on airway inflammation and asthma control is limited.

OBJECTIVE

We sought to compare airway inflammation and its relationship to asthma control in aged versus younger patients and determine whether differences are asthma specific or caused by "inflamm-aging."

METHODS

We performed a prospective study of aged (>60 years) and younger (21-40 years) inner-city patients with asthma. After a run-in period to control for inhaled corticosteroid use, induced sputum was collected. Age-matched nonasthmatic control subjects were included to measure age-related inflammatory changes.

RESULTS

Aged (mean age, 67.9 ± 5.1 years; n = 35) compared with younger (mean age, 30.8 ± 5.9 years; n = 37) asthmatic patients had significantly worse asthma control and lower FEV₁. Aged asthmatic patients had higher sputum neutrophil (30.5 × 10⁴/mL and 23.1%) and eosinophil (7.0 × 10⁴/mL and 3.8%) numbers and percentages compared with younger patients (neutrophils, 13.0 × 10⁴/mL [P < .01] and 6.9% [P < .01]; eosinophils, 2.0 × 10⁴/mL [P < .01] and 1.2% [P < .01]). Aged asthmatic patients had higher sputum IL-6 (P < .01) and IL-8 (P = .01) levels. No significant inflammatory differences between aged and younger control subjects were observed. In aged asthmatic patients increased sputum IL-6 and macrophage inflammatory protein 3α/CCL20 levels were significantly associated with decreased asthma control and increased sputum neutrophil numbers and IL-1β, IL-6, and macrophage inflammatory protein 3α/CCL20 levels were associated with hospitalization.

CONCLUSIONS

The inflammatory patterns of aged versus younger asthmatic patients are associated with increased sputum neutrophil and eosinophil values and cytokine levels related to neutrophil recruitment. Differences in airway inflammation can contribute to diminished asthma control in the aged. Further understanding of asthma pathophysiology in aged patients is needed to improve management of this vulnerable population.

Prevalence of asthma among Middle Eastern children: A systematic review

Background: The prevalence of asthma and allergy has increased during the last decades, especially in children. However, little is known about it in the Middle East region. This systematic review is aimed to estimate the prevalence of asthma among the Middle Eastern children.

Methods: Local and international scientific databases including SID, Iranmedex, Medline and Science Direct were systematically searched for relevant keywords including; asthma, prevalence, children, International Study of Asthma and Allergies in Childhood (ISACC) and the names of Middle Eastern countries for the period of 1996-2011. Papers in Persian and English which met the defined criteria were included into the study. Bibliographies of the extracted articles were also searched. After extraction of data, heterogeneity between studies and publication bias were measured using Egger's-test. Effect size was pooled by the random-effect model. Since significant heterogeneity was found between studies, univariate meta-regression analyses were done to assess the association of variables with the overall results.

Results: Fifty studies in the Middle East examined the prevalence of asthma and allergy in children under the age of 18 years according to the ISAAC criteria and were included. A total number of 289,717 children were examined in the included studies and the prevalence varied from 0.7 % in Isfahan to 22.3 % in Bagdad. The total prevalence of diagnosed asthma was calculated 7.53 % (95% Cl: 6.38-8.75). Prevalence of asthma in the 13-14 years age group was 7.57% (95% Cl: 5.78-9.29) and in 6-7 years age group was 7.43% (95% Cl: 5.75-9.10). The prevalence of asthma among girls, based on random effect model, was 6.30% (95% Cl: 4.97-7.61) and among boys, it was 8.91% (95% Cl: 6.80-11.04).

Conclusion: The prevalence of asthma in the Middle East is lower than most developed countries. However, there is not enough longitudinal data to estimate the trend over time. In order to have more accurate estimates and to provide evidence for proper planning, standard epidemiologic studies should be conducted in countries of the region.

Association between asthma and dysphonia: A population-based study

OBJECTIVE

We investigated whether asthma predisposes patients to organic laryngeal lesions or increases dysphonia in those without organic laryngeal lesions.

METHODS

We performed a cross-sectional study with data from the Korea National Health and Nutrition Examination Survey; 19,330 subjects from 2008 through 2011 were included. The associations of asthma with organic laryngeal lesions and dysphonia were analyzed using a simple/multiple logistic regression analysis with complex sampling while adjusting for confounding factors (age, sex, smoking status, stress level, and body mass index) that could contribute to dysphonia.

RESULTS

Compared with non-asthma participants, the asthma patients tended to be older and female and to have higher stress levels. These factors were associated with dysphonia (Age, AOR = 1.20, 95% CI = 1.14 = 1.23, P < 0.001; female, AOR = 1.70, 95% CI = 1.33-2.17, P < 0.001; higher stress, AOR = 1.44, 95% CI = 1.23-1.69, P < 0.001). Asthma itself was also associated with dysphonia. Compared with non-asthma participants, asthma patients who had not taken asthma medication recently showed a higher AOR (1.62; 95% CI = 1.0-2.42) for dysphonia, and asthma patients who had taken asthma medication recently showed the highest adjusted odds ratio for dysphonia (AOR = 1.97; 95% confidence interval, CI = 1.28-3.02, P = 0.001). On multiple logistic regression analysis, vocal nodules, laryngeal polyps, and laryngitis were not associated with asthma (all P > 0.05).

CONCLUSIONS

Asthma patients are predisposed to subjective dysphonia due to demographic and clinical characteristics (older age, female, and higher stress level) as well as to asthma itself. However, asthma was not associated with organic laryngeal lesions in this study.

Inverse Relationship Between Helicobacter Pylori Infection and Asthma Among Adults Younger than 40 Years: A Cross-Sectional Study

Recent studies have suggested that Helicobacter pylori could prevent allergic disease, particularly in children. However, whether this is true in adults is controversial. The aim of this study was to investigate whether there is negative association between H. pylori infection and asthma among adults in an area with a high prevalence of H. pylori.This was a cross-sectional study using 2011 health surveillance data. Blood samples were taken from all participants to measure serum H. pylori IgG status. Information on demographics, socioeconomic status, and medical history, including asthma and other allergic conditions were collected by a questionnaire.Of the 15,032 patients, 9492 (63.1%) had a history of H. pylori infection, 359 (2.4%) had asthma, and 3277 (21.8%) had other allergic conditions. H. pylori infection was positively correlated with age (OR, 1.050; 95% CI, 1.047-1.053, P < 0.001). Asthma history was positively correlated with age (OR, 1.022; 95% CI, 1.013-1.032, P < 0.001). H. pylori and age were shown to have interaction on asthma in the total participants (OR, 1.041; 95% CI, 1.021-1.062, P < 0.001). In subgroup analysis, H. pylori infection among those < 40 years old was inversely correlated with asthma (OR, 0.503; 95% CI, 0.280-0.904, P = 0.021). Other allergic conditions were not related with H. pylori infection among the total and those <40 years old.The inverse association between H. pylori infection and asthma among young adults suggests that the underlying immune mechanism induced by H. pylori infection may affect allergic reactions associated with asthma in young adults.

The impact of PM2.5 on asthma emergency department visits: a systematic review and meta-analysis

Although the relationship between asthma and exposure to fine particulate matter (PM2.5) has been frequently measured, reported conclusions have not been consistent. As emergency department (ED) visits are an effective way to estimate health outcomes for people with asthma and short-term exposure to PM2.5, this review systematically searched five databases without language or geographical restrictions from inception to January 13, 2015 to study the impact of PM2.5 on asthma ED visits. A random-effects model was used to calculate the pooled risk ratio (RR) and 95% confidence intervals (CI). With respect to short-term effects, asthma ED visits increased at higher PM2.5 concentrations (RR 1.5% per 10 μg/m(3); 95% CI 1.2-1.7%), and children were more susceptible (3.6% per 10 μg/m(3); 95% CI 1.8, 5.3%) than adults (1.7, 95% CI 0.7%, 2.8%) to increased PM2.5; the ED visits increased during the warm season by 3.7% (95% CI 0.5, 6.9%) per 10 μg/m(3) increase in PM2.5, which was higher than the corresponding increase during the cold season (2.6, 95% CI 0.7-4.6%). This demonstrates that ambient PM2.5 has an adverse impact on asthma ED visits after short-term exposure and that children are a high-risk population when PM2.5 concentrations are high, particularly in warm seasons, during which measures should be taken to prevent PM2.5.

Healthcare utilisation by pregnant patients with asthma in South Korea: a cohort study using nationwide claims data

OBJECTIVES

Few nationwide population-based studies have examined the burden of asthma during pregnancy. Here, we investigated the burden and medical treatment of asthma during pregnancy requiring healthcare utilisation in South Korea.

DESIGN

Cohort study.

SETTING

Nationwide insurance claims database.

PARTICIPANTS

A total of 1,306,281 pregnant women who delivered in South Korea in 2009-2011.

OUTCOMES

The prevalence and exacerbation rates of asthma requiring healthcare utilisation, and the prescription of antiasthmatic drugs during pregnancy.

RESULTS

The prevalence of asthma requiring healthcare utilisation was 0.43% among pregnant women. Among those with asthma requiring healthcare utilisation, 6.9% were hospitalised and treated with systemic steroids and short-acting β2-agonists during pregnancy. Oral drugs were prescribed less during the third trimester than during the first trimester (all p values for trends were <0.001). A significant number of patients with asthma were likely to stop taking antiasthmatic drugs after becoming pregnant.

CONCLUSIONS

The prevalence of asthma requiring healthcare utilisation during pregnancy was not very high. However, a significant number of women were likely to stop taking antiasthmatic drugs, and those who did tended to experience exacerbations.

Adverse Childhood Events are Related to the Prevalence of Asthma and Chronic Obstructive Pulmonary Disorder Among Adult Women in Hawaii

PURPOSE

In the US, women surpass men in the prevalence of lung diseases. Limited studies exist on the association of adverse childhood events (ACEs) to asthma and chronic obstructive pulmonary disorder (COPD) particularly among women and cohorts of understudied populations (e.g., Pacific Islanders). This study evaluated the ACEs-asthma and ACEs-COPD relationships among women in Hawaii and the contribution of poor health factors (smoking, binge drinking, and obesity) in these associations.

METHODS

Using data from 3363 women in the Behavioral Risk Factor Surveillance System-Hawaii, we assessed how self-reported ACEs [count and type (household dysfunction, and physical, verbal and sexual abuse)] relate to asthma and COPD. Multivariable log-binomial regression, accounting for the sampling design, and model adjustments for socio-demographics, healthcare access, emotional support, current smoking, binge drinking, and BMI status were used to generate prevalence ratios.

RESULTS

For every increase in ACE count, the likelihood for asthma increased by 7 % (CI = 1.02-1.13), and for COPD, by 21 % (CI = 1.12-1.31) accounting for socio-demographics, healthcare access, and emotional support. Verbal abuse was also associated with greater likelihood for asthma independent of these covariates (PR = 1.43, CI = 1.14-1.79). Household dysfunction (PR = 1.82, CI = 1.15-2.82) and physical (PR = 2.01, CI = 1.20-3.37), verbal (PR = 2.24, CI = 1.38-3.65) and sexual (PR = 1.81, CI = 1.10-2.97) abuse were all associated with COPD using similar adjustments. Additional adjustment for smoking, binge drinking, and BMI status did not impact the ACE-asthma associations and only modestly attenuated the ACE-COPD relationships.

CONCLUSIONS

Primary and secondary prevention of ACEs may optimize the health of young girls in Hawaii, and reduce the burden of asthma and COPD among women in the state.

Challenges in the Management of Asthma in the Elderly

Recent literature has emphasized the clinical and socio-epidemiological significance of asthma in the elderly. However, why the disease burden remains high in this group is unclear. Elderly subjects usually have multiple chronic illnesses, and the role played by comorbidities in the context of asthma has been underappreciated. This review aims to summarize the literature associations between comorbidities and asthma in elderly patients. In addition, we discuss patient management issues.

Urban-rural differences in the prevalence of allergen sensitization and self-reported rhinitis in the elderly population

BACKGROUND

Urbanization is frequently associated with allergic conditions during childhood; however, the literature lacks studies on the association between allergies and degree of urbanization in the elderly population.

OBJECTIVE

To determine how the degree of urbanization affects the prevalence of allergic sensitization and self-reported rhinitis symptoms in elderly community populations.

METHODS

The study population consisted of 1,311 elderly subjects identified from 2 community population cohort datasets who were divided into 3 groups according to the degree of urbanization (urban, semirural, and rural) where they resided. Current rhinitis symptoms were assessed using a questionnaire. Sensitization to inhalant allergen was measured using skin prick tests for 9 common allergens.

RESULTS

Sensitization to inhalant allergen showed a positive correlation with degree of urbanization (urban 17.2%, semirural 9.8%, rural 6.0%; P for trend <.001), with a significant correlation observed between house dust mite allergens and degree of urbanization. Self-reported rhinitis symptoms were mostly nonallergic, but showed a positive correlation with degree of urbanization (urban 26.8%, semirural 18.2%, rural 11.5%; P for trend <.001). Self-reported rhinoconjunctivitis also correlated with urbanization. Correlations between self-reported allergic conditions and urbanization remained statistically significant in multivariate logistic regression tests.

CONCLUSION

The present analyses found significant correlations between degree of urbanization with self-reported rhinitis symptoms and sensitization to inhalant allergen in the elderly population. These findings warrant further investigation of the roles that urban factors play in the development of elderly rhinitis and allergen sensitization.

Addition of Montelukast to Low-Dose Inhaled Corticosteroid Leads to Fewer Exacerbations in Older Patients Than Medium-Dose Inhaled Corticosteroid Monotherapy

Purpose

There have been few reports regarding the efficacy of antiasthmatics in older patients. To compare the efficacy of the addition of montelukast to low-dose inhaled budesonide (MON-400BUD) versus increasing the dose of inhaled steroid (800BUD) on asthma control in older asthmatics.

Methods

A randomized, open-label, parallel-designed trial was conducted for 12 weeks. The primary endpoint was the rate of patients who reached "well-controlled asthma status" after the 12-week treatment period. Additionally, asthma exacerbations, sputum inflammatory cells, asthma control test (ACT) and physical functioning scale (PFS), and adverse reactions were monitored.

Results

Twenty-four (36.9%) and 22 (34.9%) subjects in the MON-400BUD (n=65) and 800BUD (n=63) groups had well-controlled asthma at the end of the study, respectively. The numbers of asthma exacerbations requiring oral corticosteroid treatment (20 vs 9, respectively, P=0.036) and the development of sore throat (22 vs 11, respectively, P=0.045) were significantly higher in the 800BUD group than in the MON-400BUD group. Body mass index and changes in ACT, FEV1%, 6-min walk distance and PFS from baseline were all significant determinants for distinguishing subjects with well-controlled and partly controlled asthma from those with uncontrolled asthma (P<0.05) at the end of the study.

Conclusions

The efficacy of 12-week treatment with MON-400BUD in older asthmatics was comparable to that of 800BUD on asthma control but associated with reduced frequency of asthma exacerbations requiring oral steroids and sore throat events. Changes in ACT and PFS can be useful predictors of asthma control status in older patients.

Validation of the Korean version of the European Community Respiratory Health Survey screening questionnaire for use in epidemiologic studies for adult asthma

BACKGROUND

Standardized questionnaire is one of key instruments for general population surveys.

OBJECTIVE

The present study aimed to develop and validate the Korean version of the European Community Respiratory Health Survey (ECRHS) screening questionnaire for adult asthma surveys.

METHODS

The ECRHS screening questionnaire was translated into Korean language according to the international criteria. Study participants were prospectively recruited from six referral hospitals and one health check-up center. Comprehensibility of the translation was tested in a pilot study of 10 patients. The reliability was evaluated by internal consistency and test-retest repeatability. Validity was assess with regard to physician-diagnosed asthma.

RESULTS

A total of 100 adult asthma patients and 134 volunteers were recruited. Reliability was examined for 10 items in 100 asthmatics; Cronbach α coefficients were 0.84, and test-retest repeatability was good (Cohen κ coefficient, 0.71-1.00). Validity was assessed for 8 items in 234 participants; in particular, 'recent wheeze' showed a high sensitivity (0.89) for physician-diagnosed asthma. 'Recent asthma attack' and 'current asthma medication' showed high specificity (0.96-0.98).

CONCLUSION

The present study demonstrated that the Korean version of the ECRHS screening questionnaire was comprehensible, reliable and valid. We suggest the questionnaire to be utilized in further epidemiological studies for asthma in Korean adult populations.

Staphylococcal enterotoxin sensitization in a community-based population: a potential role in adult-onset asthma

BACKGROUND

Recent studies suggest that Staphylococcus aureus enterotoxin sensitization is a risk factor for asthma. However, there is a paucity of epidemiologic evidence on adult-onset asthma in community-based populations.

OBJECTIVE

We sought to evaluate the epidemiology and the clinical significance of staphylococcal enterotoxin sensitization in community-based adult populations.

METHODS

The present analyses were performed using the baseline data set of Korean adult population surveys, consisting of 1080 adults (mean age = 60.2 years) recruited from an urban and a rural community. Questionnaires, methacholine challenge tests, and allergen skin tests were performed for defining clinical phenotypes. Sera were analysed for total IgE and enterotoxin-specific IgE using ImmunoCAP.

RESULTS

Staphylococcal enterotoxin sensitization (≥ 0.35 kU/L) had a prevalence of 27.0%. Risk factors were identified as male sex, current smoking, advanced age (≥ 61 years), and inhalant allergen sensitization. Current asthma was mostly adult onset (≥ 18 years old) and showed independent associations with high enterotoxin-specific IgE levels in multivariate logistic regression tests. In multivariate linear regressions, staphylococcal enterotoxin-specific IgE level was identified as the major determinant factor for total IgE level.

CONCLUSIONS AND CLINICAL RELEVANCE

Staphylococcal enterotoxin sensitization was independently associated with adult-onset asthma in adult community populations. Strong correlations between the enterotoxin-specific IgE and total IgE levels support the clinical significance. The present findings warrant further studies for the precise roles of staphylococcal enterotoxin sensitization in the asthma pathogenesis.

[Influence of tobacco smoking on the risk of developing asthma]

The aim of this general review is to investigate the influence of active and passive smoking on the development of asthma in children and adults. Passive smoking during and after pregnancy facilitates the onset of childhood asthma and wheezing. In particular, smoking during pregnancy is associated with the occurrence of wheezing prior to the age of 4 years. In contrast, the results of studies on the relationship between parental smoking in the post-natal period and the onset of asthma or wheezing are discordant. Exposure to passive smoking during childhood facilitates the occurrence of asthma in adulthood. In adults and adolescents, active smoking appears to be a factor favoring the development of asthma. On the other hand, non-smoking adult subjects without history of asthma exposed to passive smoking have a risk of asthma. The pathophysiological mechanisms by which tobacco smoke is the cause of asthma are still poorly known. Smoking cessation is an essential component in the management of asthmatic subjects who smoke, facilitating the control of the disease.

Asthma in the elderly: what we know and what we have yet to know

In the past, asthma was considered mainly as a childhood disease. However, asthma is an important cause of morbidity and mortality in the elderly nowadays. In addition, the burden of asthma is more significant in the elderly than in their younger counterparts, particularly with regard to mortality, hospitalization, medical costs or health-related quality of life. Nevertheless, asthma in the elderly is still been underdiagnosed and undertreated. Therefore, it is an imperative task to recognize our current challenges and to set future directions. This project aims to review the current literature and identify unmet needs in the fields of research and practice for asthma in the elderly. This will enable us to find new research directions, propose new therapeutic strategies, and ultimately improve outcomes for elderly people with asthma. There are data to suggest that asthma in older adults is phenotypically different from young patients, with potential impact on the diagnosis, assessment and management in this population. The diagnosis of AIE in older populations relies on the same clinical findings and diagnostic tests used in younger populations, but the interpretation of the clinical data is more difficult. The challenge today is to encourage new research in AIE but to use the existing knowledge we have to make the diagnosis of AIE, educate the patient, develop a therapeutic approach to control the disease, and ultimately provide a better quality of life to our elderly patients.

Association of insulin resistance with bronchial hyperreactivity

Background

Several epidemiologic studies showed the significant association of insulin resistance with asthma.

Objective

The aim of this study was to evaluate the association of insulin resistance with airway hyperresponsiveness (AHR) in adult population.

Methods

1,058 subjects who visited to the Seoul National University Hospital Gangnam Center from October 2007 to January 2009 for a routine health check-up were enrolled. All subjects completed a questionnaire, anthropometric measurements such as body mass index (BMI) and waist circumference, blood tests, pulmonary function test, and methacholine bronchial provocation test (MBPT). Insulin resistance was estimated from the homeostasis model of assessment of insulin resistance (HOMA-IR).

Results

Thirty-three subjects (3.1%) had AHR based on MBPT. The subjects with AHR had higher BMI, waist circumference, and HOMA-IR than those without AHR (p < 0.001, p = 0.003, and p = 0.002, respectively). In case of men, fasting insulin level and HOMA-IR had significant correlation with forced expiratory volume in 1 second (%) (r = -0.1440, p = 0.011, and r = -0.1156, p = 0.042, respectively). Fasting insulin level and HOMA-IR were higher in men with AHR than in those without (p = 0.046 and p = 0.040, respectively). In binary logistic regression analysis after adjustment for age, HOMA-IR was the significant risk factor for AHR in men (HOMA-IR: odds ratio [OR], 3.21; 95% confidence interval [CI], 1.00-10.30). In case of women, fasting insulin, glucose level, or insulin resistance had no significant correlation with lung function. BMI, waist circumference, and HOMA-IR were significantly higher in women with AHR than in those without (p = 0.001, p = 0.011, and p = 0.010, respectively). In binary logistic regression analysis after adjustment for age, BMI and HOMA-IR were the significant risk factors for AHR in women (BMI: OR, 2.20; 95% CI, 1.23-3.82; insulin resistance: OR, 1.05; 95% CI, 1.00-1.09).

Conclusion

Insulin resistance was significantly associated with bronchial hyperreactivity, which is the most characteristic feature of asthma.

Epidemiology of adult asthma in Asia: toward a better understanding

Asia is the world's most dynamic area. Asthma is a major chronic disease in Asia, like other continents. However, unlike childhood asthma, the epidemiological burden of asthma in Asian adults has been unclear. Here we reviewed the currently available literatures on the epidemiology of adult asthma in the Asian community populations. Adult asthma prevalence was generally lower in Asian than in Europe, but the increasing trends suggested the disease burden to rise in the near future. However, for better understanding, it may be essential to prepare for the Asian multinational network for the standardization and collaboration of research.

Reference ranges and determinant factors for exhaled nitric oxide in a healthy korean elderly population

Purpose

Exhaled nitric oxide (NO) is a useful non-invasive biomarker for asthma diagnosis; however, the literature suggests that exhaled NO levels may be affected by demographic factors. The present analysis investigated determinant factors that present exhaled NO reference levels for Korean elderly adults.

Methods

For reference levels, we analyzed the baseline data of healthy adult participants in the Ansung cohort. The fraction of exhaled NO (FeNO) was measured by NIOX MINO®. The characterization of the subjects was performed through structured questionnaires, spirometry, and methacholine challenge tests. To validate the diagnostic utility of the determined reference levels, asthma patients were recruited from medical institutions for FeNO measurement.

Results

A total of 570 healthy subjects were analyzed (mean age, 59.9±12.3; male, 37.0%) for reference levels. FeNO levels significantly correlated with weight, height, body mass index, atopy, or forced expiratory volume in 1 second % predicted by simple linear regression analysis. Multiple linear regression analysis identified gender as an independent determinant for FeNO levels; subsequently, the reference values for FeNO were 18.2±10.6 ppb (5th to 95th percentile, 6.0 to 37.4 ppb) for males and 12.1±6.9 ppb (5th to 95th percentile, 2.5 to 27.0 ppb) for females. The diagnostic utility of FeNO reference levels was validated by receiver operating curve analysis (area under curve, 0.900 for males and 0.885 for females) for diagnosing asthma. The optimal cutoff values for the prediction of asthma were 30.5 ppb for males and 20.5 ppb for females.

Conclusions

The current analysis presented reference ranges and the diagnostic utility of FeNO levels for asthma in Korean elderly adults.

Influence of chronic sinusitis and nasal polyp on the lower airway of subjects without lower airway diseases

Purpose

Upper and lower respiratory tract pathologies are believed to be interrelated; however, the impact of upper airway inflammation on lung function in subjects without lung disease has not been evaluated. This study investigated the association of CT finding suggesting chronic sinusitis and lung function in healthy subjects without lung disease.

Methods

This was a retrospective study of prospectively collected data from 284 subjects who underwent a pulmonary function test, bronchial provocation test, rhinoscopy, and osteomeatal unit computed tomography offered as a private health check-up option.

Results

CT findings showed that the sinusitis group had a significantly lower FEV1/FVC ratio than subjects without sinusitis finding (78.62% vs 84.19%, P=0.019). Among the sinusitis group, subjects classified by CT findings as the extensive disease group had a slightly lower FEV1/FVC than those of the limited disease group (76.6% vs 79.5%, P=0.014) and the associations were independent of the presence of airway hyperresponsiveness. The subjects with nasal polyp had also lower FEV1 and FEV1/FVC than subjects without nasal polyp (FEV1: 100.0% vs 103.6%, P=0.045, FEV1/FVC: 77.4% vs 80.0%, P=0.005).

Conclusions

CT findings suggesting chronic sinusitis and nasal polyp were associated with subclinical lower airway flow limitation even in the absence of underlying lung disease.

Respiratory effects of the hebei spirit oil spill on children in taean, Korea

Purpose

The oil spill from the Heibei Spirit in December 2007 contaminated the Yellow Coast of South Korea. We evaluated the respiratory effects of that spill on children who lived along the Yellow Coast.

Methods

Of 662 children living in the area exposed to the oil spill, 436 (65.9%) were enrolled as subjects. All subjects completed a modified International Study of Asthma and Allergies in Childhood questionnaire. A health examination, including a skin prick test, pulmonary function test, and methacholine bronchial provocation test (MBPT), was administered. The children were assigned to two groups: those who lived close to the oil spill area and those who lived far from the oil spill area.

Results

The children who lived close to the oil spill area showed a significantly lower forced expiratory volume in one second (FEV1), an increased prevalence of 'asthma ever' (based on a questionnaire), and 'airway hyperresponsiveness' (based on the MBPT) than those who lived far from the oil spill area (FEV1; P=0.011, prevalence of 'asthma ever' based on a questionnaire; P=0.005, prevalence of 'airway hyperresponsiveness' based on the MBPT; P=0.001). The onset of wheezing after the oil spill was significantly higher in children who lived close to the oil spill area than in those who lived far from the oil spill area among the 'wheeze ever' group (P=0.002). In a multiple logistic regression analysis, male sex, family history of asthma, and residence near the oil spill area were significant risk factors for asthma (sex [male/female]: odds ratio [OR], 2.54; 95% confidence interval [CI], 1.31-4.91; family history of asthma [No/Yes]: OR, 3.77; 95% CI, 1.83-7.75; exposure group [low/high]; OR, 2.43; 95% CI, 1.27-4.65).

Conclusions

This study suggests that exposure to an oil spill is a risk factor for asthma in children.

Obesity and asthma: a coincidence or a causal relationship? A systematic review

BACKGROUND AND AIM

Epidemiological data has established increasing adiposity as a risk factor for incident asthma. However, the mechanisms underlying the association between obesity and asthma are incompletely understood. In the present paper, we review current knowledge of possible mechanisms mediating the observed association between obesity and asthma.

METHODS

Systematic literature review.

RESULTS

Obesity and asthma share some etiological factors, such as a common genetic predisposition and effects of in utero conditions, and may also have common predisposing factors such as physical activity and diet. Obesity results in important changes in the mechanical properties of the respiratory system which could explain the occurrence of asthma. However, there are also plausible biological mechanisms whereby obesity could be expected to either cause or worsen asthma. These include co-morbidities such as gastro-oesophageal reflux, complications from sleep-disordered breathing, breathing at low lung volumes, chronic systemic inflammation, and endocrine factors, including adipokines and reproductive hormones. Obesity related asthma is in general not associated with eosinophilic airway inflammation, and adipokines are likely to play important roles in the inflammatory pathogenesis of asthma in obese individuals.

CONCLUSION

The association between obesity and asthma is not straightforward, and further knowledge is clearly needed, as understanding the underlying mechanisms may lead to new therapeutic options for this high-risk part of the asthma population.