Is aging a "comorbidity" of asthma?

Aryl hydrocarbon receptor: Linking environment to aging process in elderly patients with asthma

ABSTRACT

Aging is a significant risk factor for various diseases, including asthma, and it often leads to poorer clinical outcomes, particularly in elderly individuals. It is recognized that age-related diseases are due to a time-dependent accumulation of cellular damage, resulting in a progressive decline in cellular and physiological functions and an increased susceptibility to chronic diseases. The effects of aging affect not only the elderly but also those of younger ages, posing significant challenges to global healthcare. Thus, understanding the molecular mechanisms associated with aging in different diseases is essential. One intriguing factor is the aryl hydrocarbon receptor (AhR), which serves as a cytoplasmic receptor and ligand-activated transcription factor and has been linked to the aging process. Here, we review the literature on several major hallmarks of aging, including mitochondrial dysfunction, cellular senescence, autophagy, mitophagy, epigenetic alterations, and microbiome disturbances. Moreover, we provide an overview of the impact of AhR on these hallmarks by mediating responses to environmental exposures, particularly in relation to the immune system. Furthermore, we explore how aging hallmarks affect clinical characteristics, inflammatory features, exacerbations, and the treatment of asthma. It is suggested that AhR signaling may potentially play a role in regulating asthma phenotypes in elderly populations as part of the aging process.

Allergic Phenotypes and Sarcopenia: Evidence from Observational Studies and Mendelian Randomization Analysis

Commonly affected in early-life population, the impact of allergic phenotypes on mid- or late-life health is less discussed. This study is to explore the association of allergic phenotypes including atopic dermatitis (AD), asthma, eosinophils count (EC), and sarcopenia. We conducted observational studies and mendelian randomization (MR) analysis based on UK Biobank (UKB), the China Health and Retirement Longitudinal Study (CHARLS) and data from genome-wide association study (GWAS). Based on the UKB data, AD, asthma and EC were positively correlated with pre-sarcopenia and decreased skeletal muscle mass index and hand grip in fully adjusted model. Asthma and EC were significantly associated with sarcopenia while AD was marginally associated (p = 0.095). Based on the CHARLS cohort, asthma significantly added 109.4% risk for pre-sarcopenia in adjusted model (relative risk = 2.094; p = 0.002), respectively. Both asthma (β = 0.100, p = 0.006) and EC (β = 0.023, p = 0.017) exerted significantly casual effects on pre-sarcopenia. However, as for sarcopenia, merely EC exhibited a significantly casual effect (β = 0.005, p = 0.048). Significant casual effects of AD (β = - 0.027, p = 0.003), asthma (β = - 0.029, p = 0.027) and EC (β = - 0.041, p < 0.001) on decreased appendicular lean mass (ALM) were observed using the inverse-variance weighted method and the Mendelian randomization pleiotropy residual sum and outlier (MR-PRESSO) method. Our results revealed a contributory role of AD, asthma and EC on sarcopenia, especially in terms of decreased ALM, an indicator for sarcopenia diagnosis. The findings of our study will raise the awareness of preventing aging-related disorders or geriatric syndromes among allergic populations.

Supplementary Information

The online version contains supplementary material available at 10.1007/s43657-023-00110-4.

Expert consensus recommendations for the management of asthma in older adults

Asthma is a public health problem in patients of any age, although there is still a tendency to erroneously assume that it is almost always confined to children and young people. Epidemiological studies indicate that, from the sixth decade of life, the prevalence of this disease in countries such as Spain reaches 6-10%, with a higher prevalence among women aged 64 to 75 years. In addition, two-thirds of asthma deaths occur at this stage of life, resulting in a substantial number of hospital admissions, longer hospital stays and, from a finance point of view, significant direct economic costs. Asthma in older adults (65 years or older) is now a matter of great concern, the reality of which is underestimated and undertreated. It is therefore essential to establish appropriate recommendations for the diagnosis and treatment of asthma in the aging population. This consensus, which brings together the latest evidence available, was conceived with this objective. The proposed recommendations/conclusions are the result of a nominal consensus developed throughout 2019 and validated by panellists in successive rounds of voting.

Characteristics of older adult hospitalized patients with bronchial asthma: a retrospective study

Background

Bronchial asthma is a chronic inflammation of the airways. Older adult patients with bronchial asthma are defined as patients older than 65 and with a previous or current clear diagnosis of asthma. The purpose of this study was to determine the characteristics of older adult hospitalized patients with bronchial asthma.

Methods

We retrospectively analyzed the data from patients with bronchial asthma admitted to the General Hospital of the Northern Theater Command from September 2018 to January 2020. We divided them into the older adult (≥ 65 years) and the younger (< 65 years) groups. We compared the clinical and epidemiological characteristics of the two groups.

Results

There were 181 inpatients with bronchial asthma, including 41 older adult patients, accounting for 22.7%. There were significant differences in age, sex, smoking, duration of disease, age at diagnosis of asthma, hospital stays, hospitalization costs, number of acute attacks 1 year before admission, number of hospitalizations in our hospital one year before admission, asthma control test score, forced expiratory volume in 1 s (FEV1), FEV1/FVC, the severity of acute attacks, comorbidities, and inhaled corticosteroid dose between the two groups. There were many older adult patients with asthma (mostly late-onset asthma). The hospitalization costs were high. Most patients had many comorbidities, poor asthma control, severe attack, and heavy economic burdens.

Conclusion

Attention should be focused on achieving asthma control in older adult patients to improve their quality of life and reduce their economic burdens.

Aberrant Methylation of Aging-Related Genes in Asthma

Background: Asthma is a complex pulmonary inflammatory disease which is common among older adults. Aging-related alterations have also been found in structural cells and immune cells of asthma patients. Nonetheless, the underlying mechanism by which differenced aging-related gene contributes to asthma pathology remains unclear. Of note, DNA methylation (DNAm) has been proven to play a critical mechanism for age-related gene expression changes. However, the methylation changes of aging-related genes in asthma patients are still obscure.

Methods: First, changes in DNAm and gene expression were detected with multiple targeted bisulfite enrichment sequencing (MethTarget) and qPCR in peripheral blood of 51 healthy controls (HCs) and 55 asthmatic patients. Second, the correlation between the DNAm levels of specific altered CpG sites and the pulmonary function indicators of asthma patients was evaluated. Last, the receiver operator characteristic (ROC) curve and principal component analysis (PCA) were used to identify the feasibility of the candidate CpG sites as biomarkers for asthma.

Results: Compared with HCs, there was a differential mRNA expression for nine aging-related genes in peripheral blood of asthma patients. Besides, the methylation levels of the nine aging-related genes were also altered in asthma patients, and a total of 68 CpG sites were associated with the severity of asthma. Notably, 9 of the 68 CpG sites were significantly associated with pulmonary function parameters. Moreover, ROC curve and PCA analysis showed that the candidate differential methylation sites (DMSs) can be used as potential biomarkers for asthma.

Conclusions: In summary, this study confirmed the differentially expressed mRNA and aberrant DNAm level of aging-related genes in asthma patients. DMSs are associated with the clinical evaluation indicators of asthma, which indicate the involvement of aging-related genes in the pathogenesis of asthma and provide some new possible biomarkers for asthma.

Determinants of uncontrolled asthma among adult asthmatic patients on follow-up at chest clinic of Jimma medical center: unmatched case-control study

OBJECTIVE

To identify the determinants of uncontrolled asthma among asthmatic patients on follow-up at Jimma Medical Center.

METHODS

Institution-based case-control study was conducted on asthmatic patients who were on follow-up at the chest clinic of Jimma University Medical (JMC) from March to May 2020. A total of 59 cases and 118 controls (1: 2 ratio) were included in the study. Cases and controls were defined based on asthma control test (ACT) scores where those who had scores of ≤19 and above 19 were defined to be cases and controls, respectively.

RESULTS

Age of the patients [AOR: 2.78; 95% CI: 1.14, 6.81], age of the cases' residential houses [AOR: 3.65; 95% CI: 1.30, 10.28], presence of pets within the houses [AOR: 2.78; 95% CI: 1.29, 5.96], having rhinitis [AOR: 3.34; 95% CI: 1.17, 9.52], past asthma exacerbation [AOR: 2.38, 95% CI: 1.05, 5.40], non-adherence to treatment [AOR: 2.81; 95% CI: 1.30, 6.08] and smoking [AOR: 7.09; 95% CI: 1.84, 27.33] were found to be determinants of uncontrolled asthma.

CONCLUSIONS

Uncontrolled asthma results from multiple sociodemographic, environmental, clinical, and behavioral factors. Therefore, patients should be counseled on avoiding pets, maintenance of houses, adherence to treatment, quitting smoking, and early treatment-seeking for rhinitis and asthma exacerbation to improve asthma control comprehensively.

Caveolae, caveolin-1 and lung diseases of aging

INTRODUCTION

Flask-shaped plasma membrane (PM) invaginations called caveolae and their constitutive caveolin and cavin proteins regulate cellular function via plasma membrane and intracellular signal transduction pathways. Caveolae are present in a variety of cells in the lung including airway smooth muscle (ASM) where they interact with other proteins, receptors, and ion channels and thereby have the potential to affect both normal and disease processes such as inflammation, contractility, and fibrosis. Given their involvement in cell signaling, caveolae may play important roles in mediating and modulating aging processes, and contribute to lung diseases of aging. Areas covered: This review provides a broad overview of the current state of knowledge regarding caveolae and their constituent proteins in lung diseases in the elderly and identifies potential mechanisms that can be targeted for future therapies. Expert Commentary: Caveolin-1 may play a protective role in lung disease. What is less clear is whether altered caveolin-1 with aging is a natural process, or a biomarker of disease progression in the elderly.