Diseases concomitant with asthma in middle-aged and elderly subjects in Korea: a population-based study

Meta-Analysis of the Association Between Asthma and the Risk of Stroke

Introduction

Asthma and stroke share many risk factors. Previous meta-analysis has indicated that asthma is associated with an increased risk of stroke. However, this study were limited by the small number of articles included and the lack of subgroup analyses of different stroke types and different populations. This meta-analysis aimed to synthesize evidence systematically to investigate the impact of asthma on stroke.

Methods

We searched Medline (via PubMed), Web of Science and EMBASE databases and manually identified eligible studies (inception dates to December 25, 2021) that analyzed the association between asthma and stroke. We conducted quality assessment to evaluate the risk of bias of studies and sensitivity analyses to test the robustness of results.

Results

We included 8 cohort studies and 10 cross-sectional studies comprised 3,011,016 participants. We found patients with asthma had a higher risk of stroke than patients without asthma [relative risk (RR): 1.34, 95% confidence interval (CI): 1.21–1.47]. Moreover, asthma significantly increased the risk of ischemic stroke (RR: 1.25, 95% CI: 1.06–1.47) without increasing the risk of hemorrhagic stroke (RR: 1.08, 95% CI: 0.87–1.34). Asthma increased the risk of stroke in both men (RR: 1.20, 95% CI: 1.10–1.32) and women (RR: 1.29, 95% CI: 1.12–1.48) with no significant difference between the sexes. We also found that patients with inactive asthma, child-onset asthma, or no smoking history did not have an increased risk of stroke.

Conclusions

These results supported the finding that asthma could significantly increase the risk of stroke, but this impact was not consistent in different populations.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=290745, identifier: CRD42021290745.

A nationwide survey of the association between nonalcoholic fatty liver disease and the incidence of asthma in Korean adults

Background

Asthma and nonalcoholic fatty liver disease (NAFLD) are chronic diseases known to be associated with metabolic abnormalities. We aimed to clarify the association between NAFLD and asthma incidence in a large population-based cohort.

Methods and findings

We selected 160,603 individuals without comorbidities from the National Health Insurance Service-National Sample cohort between 2009 and 2014. NAFLD was defined using a surrogate marker, fatty liver index (FLI). During a median of 5.08 years’ follow-up, 16,377 subjects (10.2%) were newly diagnosed with asthma and categorized into three groups according to FLI. The cumulative incidence of asthma was higher in subjects with higher vs. lower FLIs (FLI < 30, 10.1%; 30 ≤ FLI < 60, 10.8%; FLI ≥ 60, 10.5%). Higher FLI was associated with an increased incidence of asthma (Hazard ratios (HR)_{highest vs. lowest FLI}, 1.25; 95% CI, 1.15–1.36). The results using another definition of NAFLD, as measured by the hepatic steatosis index (HSI), were similar to the primary results. This association was more pronounced in women than in men (HR 1.46; 95% CI, 1.13–1.64 vs. HR 1.07; 95% CI, 0.94–1.20).

Conclusions

This study demonstrated that NAFLD, as measured by FLI and HSI, may influence the incidence rates of asthma in adults, especially in women.

Traditional Chinese medicine use may reduce medical utility in patients with asthma: a nationwide population-based retrospective cohort study

BACKGROUND

Many patients with atopic diseases, including asthma, have sought complementary and alternative medicine and traditional Chinese medicine (TCM) treatments. But, limited clinical studies have yet examined TCM effects on medical utility in asthma patients.

AIM

To assess the medical utility of TCM in patients with asthma.

DESIGN

Population-based retrospective cohort study.

METHODS

We performed a 13-year population-based retrospective cohort study. A total of 5235 asthma patients who were TCM users and 5235 propensity-score matched asthma patients who never used TCM were sampled from the Taiwan National Health Insurance Research Database from 2000 to 2012. We compared these two groups of patients to calculate their medical utility, including numbers of emergency visits and hospitalizations until 2013. Univariate analyses were performed using Chi-square tests for dichotomous variables and t-tests for continuous variables. Cox proportional hazard models were conducted to investigate the medical utility of asthma after TCM use.

RESULTS

Compared with non-TCM patients, TCM patients had a significantly decreased medical utility of asthma admission [adjusted odds ratio (OR) = 0.63; 95% confidence interval (CI): 0.46-0.85; P < 0.05], especially in patients who used TCM for >60 days. Asthma medical utility in asthma emergencies was significantly higher for male than for female patients (adjusted OR = 1.45; 95% CI: 1.08-1.96). The most frequently used TCMs for asthma control or cough treatment were antitussive agents.

CONCLUSION

This population-based retrospective cohort study showed a significantly decreased medical utility of emergency visits and admissions in TCM patients, especially using TCM for >60 days.

Asthma and metabolic syndrome: a comprehensive systematic review and meta-analysis of observational studies

Introduction: This study aimed to perform a meta-analysis on the prevalence of metabolic syndrome (MetS) among patients with asthma and to measure the association asthma has with MetS.

Methods: The Web of Science, Medline, Scopus, Embase and Google Scholar were searched using the "Asthma", "Metabolic Syndrome", "Dysmetabolic Syndrome", "Cardiovascular Syndrome", "Insulin Resistance Syndrome", "Prevalence", "Odds Ratio", "Cross-Sectional Studies", and "Case-Control Studies" keywords. All observational studies reporting the prevalence of MetS among people with and without asthma were included in the study. In the presence of heterogeneity, random-effects models were used to pool the prevalence and odds ratios (OR), as measures of association in cross-sectional and case-control/ cohort studies, respectively.

Results: The prevalence of MetS among patients with asthma (8 studies) and the OR comparing the prevalence of MetS among patients with and without asthma (5 studies) were pooled separately. The pooled prevalence of MetS among patients with asthma was found to be 25% (95% confidence interval (CI): 13%–38%). In contrast, the overall pooled OR for MetS in patients with asthma, compared to healthy controls, was 1.34 (95% CI: 0.91–1.76), which was not statistically significant.

Conclusion: The prevalence of MetS was relatively high in patients with asthma. Furthermore, the odds of MetS was higher in patients with asthma, compared to healthy controls, although this difference was not statistically significant. More original studies among different populations are needed in order to more accurately examine the association between asthma and MetS, as well as the relationship asthma has with the individual components of MetS.

Metabolic aspects of the relationship of asthma and obesity

Asthma and obesity are serious medical and social world problems, and their combined course is characterized by a decrease in the quality of life, an increase in the frequency and duration of hospitalization. The present review summarizes the current views on the mechanisms of formation of asthma phenotype combined with obesity, role of leptin and adiponectin imbalance in the development of systemic inflammation in obesity in the pathophysiology of asthma, its interrelations with metabolic syndrome. We present data that shows that syndrome is closely related not only to the debut of asthma, but also to a decrease in its control. Along with obesity, the role of other components of metabolic syndrome, in particular insulin resistance, as a predictor of asthma development is considered. Insulin resistance may be the most likely factor in the relationship between asthma and obesity, independent of other components of the metabolic syndrome. Insulin resistance associated with obesity can lead to disruption of nitric oxide synthesis. We reveal common mechanism of metabolic disorders of nitric oxide and arginine in metabolic syndrome and asthma and show that insulin resistance treatment can be therapeutically useful in patients with asthma in combination with obesity.

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.

Allergic disorders and risk of depression: A systematic review and meta-analysis of 51 large-scale studies

BACKGROUND

Previous studies have suggested that allergic disorders are associated with an increased risk of depression. However, the results are conflicting.

OBJECTIVE

To determine the association between allergic disorders and depression based on large-scale studies.

METHODS

We reviewed relevant articles obtained from PubMed and Embase. Studies were eligible if they reported an association between allergic disorders and depression and provided available data. Study selection, data extraction, and analyses were undertaken. Pooled relative risks (RRs) with 95% confidence intervals (CIs) were calculated.

RESULTS

Of 1,827 studies identified, 51 including more than 2.5 million participants met our inclusion criteria. Overall, the results showed that allergic disorders were associated with a significant increased risk of depression (pooled RR 1.59, 95% CI 1.48-1.71). A higher risk of depression also was observed in patients with asthma (RR 1.59, 95% CI 1.46-1.74) and those with allergic rhinitis (RR 1.57, 95% CI 1.27-1.93). Subgroup analyses were conducted based on sex and age. Children (RR 1.66, 95% CI 1.41-1.96) and adults (RR 1.58, 95% CI 1.44-1.74) with allergic disorders had a higher risk of depression than controls. However, no significant association was found between allergic disorders and risk of depression in male subjects (RR 1.37, 95% CI 0.98-1.91), but a positive association was detected in female subjects (RR 1.65, 95% CI 1.44-1.89).

CONCLUSION

The results from our study showed that allergic disorders significantly increased the risk of depression.

Leukotriene Receptor Antagonists for the Treatment of Asthma in Elderly Patients

Elderly asthma (EA) is regarded as a distinct phenotype of asthma and is associated with age-related changes in airway structure and alterations in lung function and immune responses. EA is difficult to diagnose because of aging and co-morbidities, and overlaps with fixed airway obstructive disease. Novel modalities to differentiate between EA and chronic obstructive pulmonary disease (COPD) are necessary. A multifaceted approach, including clinical history, smoking habits, atopy, and measurement of lung function, is mandatory to differentiate asthma from COPD. There are a variety of co-morbidities with EA, of which COPD, upper airway diseases, depression, obesity, and hypertension are the most common, and these co-morbidities can affect the control status of EA. However, leukotriene receptor antagonists (LTRAs) can facilitate the management of EA, and thus addition of an LTRA to inhaled corticosteroid (ICS) monotherapy or ICS plus long-acting β₂-agonist therapy improves symptoms in EA patients. LTRA treatment is safe and beneficial in patients who are unable to use inhalation devices properly or who have co-morbid diseases. Therefore, clinical studies targeting a specific population of EA patients are warranted to help achieve a better therapeutic strategy in EA patients.

Predictors of asthma control in elderly patients

PURPOSE OF REVIEW

We are in the era of rapid aging of the global population. Elderly asthmatic patients have an increased frequency of hospitalization and a high mortality rate. In this review, we focus on comorbidities and treatment issues in terms of the predictors of asthma control in the elderly.

RECENT FINDINGS

Some frequent comorbidities, such as chronic obstructive pulmonary disease, chronic sinusitis, obesity, and depression, are associated with uncontrolled asthma in elderly asthmatic patients. Smoking status in elderly asthmatic patients was associated with more frequent exacerbations. Management of comorbidities should be taken into account when we treat elderly asthmatic patients. Low treatment adherence, which is common in elderly asthmatic patients, predicts poor asthma control status. A poor knowledge about asthma, cognitive function impairment, and inappropriate inhaler technique result in low treatment adherence. Polypharmacy is associated with low treatment adherence, adverse drug reactions, and drug-drug interactions, and it is supposed to be a predictor of asthma control.

SUMMARY

Multifactorial assessments, including comorbidities, treatment adherence, and polypharmacy, are important for better asthma control in elderly asthmatic patients. Further studies on the strategy for the management of elderly asthmatic patients in a real-world setting are warranted.

Plasma LTE4/PGF2α Ratio and Blood Eosinophil Count Are Increased in Elderly Asthmatics With Previous Asthma Exacerbation

The tools for asthma control assessment recommended by the current guideline are cognitive function- and effort-dependent, which is substantially impaired in the elderly. The aim of this study is to investigate objective assessment tools of asthma control status and previous asthma exacerbation (AE) in elderly subjects. Asthmatics aged >60 years who were treated with step 2 or 3 by the Global Initiative for Asthma (GINA) guideline were enrolled. During the 12-week study period, the subjects used either 400 µg of budesonide plus 10 mg of montelukast or 800 µg of inhaled budesonide. The occurrence of AE during the 4-week run-in and 12-week treatment period was monitored. After 12-week of treatment, sputum eosinophil count, peripheral eosinophil count, the plasma leukotriene E₄ (LTE₄), and prostaglandin F_2α (PGF_2α) metabolite levels were measured using the UHPLC/Q-ToF MS system. The study subjects were divided into group 1 (asthmatics who experienced AE during the study period) and group 2 (those who did not). A total of 101 patients aged 60-85 years were enrolled. Twenty-three patients (22.8%) had experienced AE. The plasma LTE₄ level, LTE₄/PGF_2α ratio, and peripheral eosinophil count were significantly higher in group 1 than in group 2 (P=0.023, P=0.010, P=0.033, respectively). The plasma LTE₄/PGF_2α ratio and peripheral eosinophil count at week 12 were significantly associated with previous AE (odds ratio [OR]=1.748, P=0.013; OR=1.256, P=0.027). Receiver operating characteristic (ROC) curves to discriminate the subjects with previous AE, including these 2 parameters, showed that the area under the curve was 0.700 (P=0.004), with 73.9% sensitivity and 47.9% specificity. In conclusion, a combination of plasma LTE₄/PGF_2α ratio and peripheral eosinophil count can be an objective assessment tool which is significantly associated with asthma control status in elderly asthmatics.

Comorbidity in severe asthma requiring systemic corticosteroid therapy: cross-sectional data from the Optimum Patient Care Research Database and the British Thoracic Difficult Asthma Registry

OBJECTIVE

To determine the prevalence of systemic corticosteroid-induced morbidity in severe asthma.

DESIGN

Cross-sectional observational study.

SETTING

The primary care Optimum Patient Care Research Database and the British Thoracic Society Difficult Asthma Registry.

PARTICIPANTS

Optimum Patient Care Research Database (7195 subjects in three age- and gender-matched groups)-severe asthma (Global Initiative for Asthma (GINA) treatment step 5 with four or more prescriptions/year of oral corticosteroids, n=808), mild/moderate asthma (GINA treatment step 2/3, n=3975) and non-asthma controls (n=2412). 770 subjects with severe asthma from the British Thoracic Society Difficult Asthma Registry (442 receiving daily oral corticosteroids to maintain disease control).

MAIN OUTCOME MEASURES

Prevalence rates of morbidities associated with systemic steroid exposure were evaluated and reported separately for each group.

RESULTS

748/808 (93%) subjects with severe asthma had one or more condition linked to systemic corticosteroid exposure (mild/moderate asthma 3109/3975 (78%), non-asthma controls 1548/2412 (64%); p<0.001 for severe asthma versus non-asthma controls). Compared with mild/moderate asthma, morbidity rates for severe asthma were significantly higher for conditions associated with systemic steroid exposure (type II diabetes 10% vs 7%, OR=1.46 (95% CI 1.11 to 1.91), p<0.01; osteoporosis 16% vs 4%, OR=5.23, (95% CI 3.97 to 6.89), p<0.001; dyspeptic disorders (including gastric/duodenal ulceration) 65% vs 34%, OR=3.99, (95% CI 3.37 to 4.72), p<0.001; cataracts 9% vs 5%, OR=1.89, (95% CI 1.39 to 2.56), p<0.001). In the British Thoracic Society Difficult Asthma Registry similar prevalence rates were found, although, additionally, high rates of osteopenia (35%) and obstructive sleep apnoea (11%) were identified.

CONCLUSIONS

Oral corticosteroid-related adverse events are common in severe asthma. New treatments which reduce exposure to oral corticosteroids may reduce the prevalence of these conditions and this should be considered in cost-effectiveness analyses of these new treatments.

Predictors of Asthma Control by Stepwise Treatment in Elderly Asthmatic Patients

The geriatric population is increasing, and asthma severity increases with age. We determined the predictors of asthma control, exacerbation, and the factors that affect asthma-specific quality of life (A-QOL) in elderly asthmatic patients. This was a prospective, multicenter, real-life study for 6 months with stepwise pharmacologic treatment based on the Global Initiative for Asthma (GINA) guideline. A total of 296 asthmatic patients aged ≥ 60 yr were recruited from 5 university centers in Korea. The improved-asthma control group was defined as the group of patients who maintained well-controlled or improved disease and the not-improved asthma control group was defined as the remaining patients. Fewer number of medications for comorbidities (2.8 ± 3.3 in the improved vs. 4.5 ± 4.4 in the control) and higher physical functioning (PF) scale (89.8 ± 14.2 in the improved vs. 82.0 ± 16.4 in the control) were significant predictors in the improved-asthma control group (OR = 0.863, P = 0.004 and OR = 1.028, P = 0.018, respectively). An asthma control test (ACT) score of ≤ 19 at baseline was a significant predictor of asthma exacerbation (OR = 3.938, P = 0.048). Asthma duration (F = 5.656, P = 0.018), ACT score (F = 12.237, P = 0.001) at baseline, and the presence of asthma exacerbation (F = 5.565, P = 0.019) were significant determinants of changes in A-QOL. The number of medications for comorbidities and performance status determined by the PF scale may be important parameters for assessing asthma control in elderly asthmatic patients.

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.

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.

Asthma and metabolic syndrome: Current knowledge and future perspectives

Asthma and obesity are epidemiologically linked; however, similar relationships are also observed with other markers of the metabolic syndrome, such as insulin resistance and dyslipidemia, which cannot be accounted for by increased body mass alone. Obesity appears to be a predisposing factor for the asthma onset, both in adults and in children. In addition, obesity could make asthma more difficult to control and to treat. Although obesity may predispose to increased Th2 inflammation or tendency to atopy, other mechanisms need to be considered, such as those mediated by hyperglycaemia, hyperinsulinemia and dyslipidemia in the context of metabolic syndrome. The mechanisms underlying the association between asthma and metabolic syndrome are yet to be determined. In the past, these two conditions were believed to occur in the same individual without any pathogenetic link. However, the improvement in asthma symptoms following weight reduction indicates a causal relationship. The interplay between these two diseases is probably due to a bidirectional interaction. The purpose of this review is to describe the current knowledge about the possible link between metabolic syndrome and asthma, and explore potential application for future studies and strategic approaches.

Prevalence and risk factors for depression in Korean adult patients with asthma: is there a difference between elderly and non-elderly patients?

Depression is an important comorbidity of asthma. However, little information is available about depression and its potential impact on asthma control in Korean adult asthma patients. We aimed to estimate the prevalence and risk factors for depression in Korean adults with persistent asthma. The 127 non-elderly (20-64 yr) and 75 elderly (≥65 yr) patients with asthma were recruited. Demographic and clinical data were extracted, and the patients completed the Asthma Specific Quality of Life (AQOL) questionnaire and asthma control test (ACT). Depression status was defined using the Korean version of the Patient Health Questionnaire-9 (PHQ-9). Depression was more prevalent in non-elderly (18.9%) than in elderly patients with asthma (13.3%). Patients with depression were significantly younger, had lower economic status, shorter disease duration, poorer asthma control, and worse AQOL scores (P<0.05). Within the non-elderly group, younger age and shorter disease duration were significantly associated with depression (P<0.05). Within the elderly group, a higher body mass index and current smoking status were significantly associated with depression (P<0.05). The PHQ-9 score was significantly correlated with worse ACT and AQOL scores in both groups. In conclusion, depression is strongly associated with poor asthma control and quality of life in Korean adult asthma patients. Our results provide important clues that used to target modifiable factors which contribute to development of depression in asthma patients.

Disease control in patients with asthma is associated with alexithymia but not with depression or anxiety

This observational cohort study investigated the relationship between alexithymia, coping strategies, anxiety, depression, pulmonary function, and disease control in bronchial asthma (BA) patients who attended a tertiary care center between December 2010 and November 2011. Participants (N = 117) were administered self-report scales measuring anxiety, depression, alexithymia, and coping strategies. Pulmonary function expressed as forced expiratory volume in the first second (FEV1), forced vital capacity (FVC), forced expiratory flow rate over the middle 50% of the FVC (FEF25-75) as% predicted and FEV1/FVC as%, fractional exhaled nitric oxide (FeNO) in ppb and the Asthma Control Test (ACT) were recorded. A hierarchical cluster analysis revealed two clusters of patients with different FEV1 values (p < .001) and alexithymia scores (p < .001). The cluster with lower FEV1 and higher alexithymia used more maladaptive coping strategies (p < .05), and had lower ACT scores (p < .05). Alexithymia was significantly associated with the severity of depression and anxiety symptoms (p < .001 for each comparison). In BA patients, alexithymia was associated with worse pulmonary function and disease control and a more frequent use of maladaptive coping strategies. These results support a multidimensional approach to asthmatic patients, including psychoeducational and behavioral interventions aimed at reducing maladaptive coping strategies.

Prevalence of asthma and its association with rhinitis in the elderly

BACKGROUND

Asthma and rhinitis are frequent respiratory diseases in children and adults. Despite the increase in the aging population, there are few epidemiologic data on both diseases in the elderly. So far, no population-based study has analyzed the association between asthma and rhinitis symptoms and severity in this age group. This study aimed to estimate the prevalence of physician-diagnosed asthma in the population aged ≥65 years in mainland Portugal and to evaluate its association with the presence and classification of rhinitis according to ARIA recommendations, in this age group.

METHODS

A cross-sectional, nationwide, population-based survey of individuals aged ≥65 years, living in mainland Portugal was performed.

RESULTS

Data were obtained from 3678 respondents. The prevalence of physician-diagnosed asthma was 10.9% (95% confidence interval (95%CI) 9.9-11.9). The frequency of asthma diagnosis increased with the number of nasal symptoms (p < 0.001). A strong association between asthma and rhinitis was found (odds ratio (OR) 13.86 (95%CI 10.66-18.02)). The strength of this association increased with the persistence and severity of rhinitis, being particularly high in elderly subjects with moderate-severe persistent rhinitis (OR 39.9 (95%CI 27.5-58.0)).

CONCLUSIONS

Asthma is common in the elderly and strongly associated with rhinitis. The OR for asthma is especially high in persistent and severe ARIA classification rhinitis types. This study strengthens the need for an integrated assessment of asthma together with rhinitis in the elderly.

Insulin and the lung: connecting asthma and metabolic syndrome

Obesity, metabolic syndrome, and asthma are all rapidly increasing globally. Substantial emerging evidence suggests that these three conditions are epidemiologically and mechanistically linked. Since the link between obesity and asthma appears to extend beyond mechanical pulmonary disadvantage, molecular understanding is necessary. Insulin resistance is a strong, independent risk factor for asthma development, but it is unknown whether a direct effect of insulin on the lung is involved. This review summarizes current knowledge regarding the effect of insulin on cellular components of the lung and highlights the molecular consequences of insulin-related metabolic signaling cascades that could adversely affect lung structure and function. Examples include airway smooth muscle proliferation and contractility and regulatory signaling networks that are associated with asthma. These aspects of insulin signaling provide mechanistic insight into the clinical evidence for the links between obesity, metabolic syndrome, and airway diseases, setting the stage for novel therapeutic avenues targeting these conditions.

Chronic airway-induced allergy in mice modifies gene expression in the brain toward insulin resistance and inflammatory responses

BACKGROUND

Chronic systemic inflammation affects brain functionality and may negatively influence the progression of neurodegenerative disorders. Allergy is a chronic inflammatory disease affecting more than 20% of the Western population. Little is known regarding the influence of allergy on brain functions. The aim of the present study was to obtain a global overview of the genes that drive the effects of peripheral inflammation associated with chronic airway-induced allergy in the brain.

METHODS

Airway allergy was induced in C57B/6J mice using ovalbumin as the allergen. Microarray analysis was performed in the hippocampus and frontal cortex in association with Affymetrix. For the data analysis, principal component analysis and orthogonal to latent structures discriminant analysis followed by pathway analysis were used. Quantitative polymerase chain reaction (qPCR) and protein analysis by Western blotting were performed for the validation of microarray results.

RESULTS

Microarray analysis showed low-grade changes in gene expression in the brain induced by airway-associated allergy. Changes in expression were observed for genes involved in antigen processing and presentation, cytokine-cytokine interaction, Toll-like receptor and mitogen-activated protein kinase signaling, as determined by pathway analysis. We confirmed a reduction of insulin-degrading enzyme at the protein level and a decrease in insulin receptor phosphorylation in the brains of allergic mice. Other allergy-induced gene expression changes were confirmed by qPCR, including increased levels of tumor necrosis factor receptor superfamily member 23 and lipopolysaccharide-binding protein.

CONCLUSION

Airway-associated allergy induces changes in brain gene expression toward induction of insulin resistance and inflammatory responses with potential implications for neurodegenerative disorders.