Differences Between Early- and Late-Onset Asthma: Role of Comorbidities in Symptom Control

Asthma Is Associated With Increased Sickness Absence Among Young Adults

BACKGROUND

There is limited knowledge about how asthma affects sickness absence in young adulthood.

OBJECTIVE

To examine how asthma and different asthma phenotypes affect sickness absence among young adults and potential modifying factors. A secondary aim was to estimate productivity losses related to sickness absence for asthma.

METHODS

The study included 2391 participants from the Swedish population-based cohort BAMSE (Barn/Child, Allergy, Milieu, Stockholm, Epidemiology). Information on asthma, asthma phenotypes, and lifestyle factors was collected from questionnaires and clinical examinations at age approximately 24 years (2016-2019). Information on sickness absence for longer than 14 days was obtained from a national register for the years 2020 and 2021. Associations between asthma, asthma phenotypes, and sickness absence were analyzed with logistic regression models adjusted for sex, birth year, education, and overweight status.

RESULTS

At age 24 years, 272 (11.4%) fulfilled the definition of asthma. Sickness absence was more common among those with asthma than among those without (15.1% vs 8.7%; P = .001; adjusted odds ratio 1.73; 95% CI, 1.19-2.51). Analyses of asthma phenotypes showed that the association tended to be stronger for persistent asthma, uncontrolled asthma, and asthma in combination with rhinitis; no consistent differences were observed across phenotypes related to allergic sensitization or inflammation. The association tended to be stronger among those with overweight than among those with normal weight. Asthma, especially uncontrolled asthma, was associated with higher productivity losses from sickness absence.

CONCLUSIONS

Asthma may be associated with higher sickness absence and productivity losses. Achieving better asthma control and reducing allergic symptoms may reduce sickness absence among individuals with asthma.

To investigate the function of age-related genes in different subtypes of asthma based on bioinformatics analysis

Asthma is a heterogeneous airway inflammatory disease that can be classified according to the inflammatory phenotype. The pathogenesis, clinical features, response to hormone therapy, and prognosis of different inflammatory phenotypes differ significantly. This condition also refers to age-related chronic ailments. Here, we intend to identify the function of aging-related genes in different inflammatory phenotypes of asthma using bioinformatic analyses. Initially, the research adopted the GSEA analysis to understand the fundamental mechanisms that govern different inflammatory phenotypes of asthma pathogenesis and use the CIBERSORT algorithm to assess the immune cell composition. The differentially expressed genes (DEGs) of eosinophilic asthma (EA), neutrophilic asthma (NA), and paucigranulocytic asthma (PGA) were identified through the limma R package. Aging-related genes, screened from multiple databases, were intersected with DEGs of asthma to obtain the asthma-aging-related DEGs. Then, the GO and KEGG pathway enrichment analyses showed that the NA- and EA-aging-related DEGs are involved in the various cytokine-mediated signaling pathways. PPI network and correlation analysis were performed to identify and evaluate the correlation of the hub genes. Further, the clinical characteristics of asthma-aging-related DEGs were explored through ROC analysis. 3 and 12 aging-related DEGs in EA and NA patients show high diagnostic accuracy, respectively (AUC >0.7). This study provided valuable insights into aging-related gene therapy for phenotype-specific asthma. Moreover, the study suggests that effective interventions against asthma may operate by disrupting the detrimental cycle of "aging induces metabolic diseases, which exacerbate aging".

Sex differences in asthma control, lung function and exacerbations: the ATLANTIS study

BACKGROUND

Asthma is a heterogeneous disease with a prevalence and severity that differs between male and female patients.

QUESTION

What are differences between male and female patients with asthma with regard to asthma control, lung function, inflammation and exacerbations?

METHODS

We performed a post hoc analysis in the ATLANTIS (Assessment of Small Airways Involvement in Asthma) study, an observational cohort study including patients with asthma from nine countries with a follow-up of 1 year during which patients were characterised with measures of large and small airway function, questionnaires, inflammation and imaging. We compared differences in baseline characteristics and longitudinal outcomes between male and female patients with asthma.

RESULTS

773 patients were enrolled; 450 (58%) of these were female. At baseline, female patients with asthma were in higher Global Initiative for Asthma (GINA) steps (p=0.042), had higher Asthma Control Questionnaire 6 (F: 0.83; M: 0.66, p<0.001) and higher airway resistance as reflected by uncorrected impulse oscillometry outcomes (ie, R5-R20: F: 0.06; M: 0.04 kPa/L/s, p=0.002). Male patients with asthma had more severe airway obstruction (forced expiratory volume in 1 s/forced vital capacity % predicted: F: 91.95; M: 88.33%, p<0.01) and more frequently had persistent airflow limitation (F: 27%; M: 39%, p<0.001). Blood neutrophils were significantly higher in female patients (p=0.014). With Cox regression analysis, female sex was an independent predictor for exacerbations.

INTERPRETATION

We demonstrate that female patients are in higher GINA steps, exhibit worse disease control, experience more exacerbations and demonstrate higher airway resistance compared with male patients. The higher exacerbation risk was independent of GINA step and blood eosinophil level. Male patients, in turn, have a higher prevalence of persistent airflow limitation and more severe airflow obstruction. These findings show sex can affect clinical phenotyping and outcomes in asthma.

TRIAL REGISTRATION NUMBER

NCT02123667.

Characteristics of asthma in an older adult population according to sex and control level: why are asthma symptoms in older women not well-controlled?

OBJECTIVE

The older adult population in Turkey has increased by 22.6% in the last 5 years, and the characteristics of such patients with asthma remain uninvestigated. Therefore, we aimed to evaluate the characteristics of older adults with asthma according to sex and asthma control status to provide an in-depth overview of asthma in this population in Turkey.

METHODS

The data of older adults (age 65 years and over) with asthma were obtained from a multicenter, cross-sectional asthma database registry (Turkish Adult Asthma Registry, TAAR) funded by the Turkish Thoracic Society. Comparisons were made based on sex and asthma control levels using the Global Initiative for Asthma (GINA) Asthma Symptom Control Questionnaire.

RESULTS

Of the 2053 (11.5%) patients registered with the TAAR, 227 were older adults (median age, 69 (8), women, 75.8% (n = 172)). Of these, 46.5% (n = 101) had obesity to some degree. Compared with men, women had lower education, income levels, and employment rates. Additionally, women exhibited a higher prevalence of obesity, hypertension, and thyroid gland disease than men. Being female (OR: 2.99; 95% CI: 1.307-6.880), the presence of gastroesophageal reflux disease (OR: 2.855; 95% CI: 1.330-6.130), and a predicted forced expiratory volume in the first-second value lower than 80% (OR: 2.938; 95% CI: 1.451-5.948) were associated with poorly controlled asthma.

CONCLUSIONS

Herein, older adults comprised 11.5% of adult patients with asthma. Being female poses a disadvantage in terms of both asthma prevalence and control in the older adult asthmatic population owing to the prevalence of comorbidities and socioeconomic sex-related distinguishing factors.

Association of Small Airway Functional Indices With Respiratory Symptoms and Comorbidity in Asthmatics: A National Cross-Sectional Study

Background

Small airway dysfunction (SAD) and airway inflammation are vital in asthma exacerbations. Type 2 inflammation (T2), mediated by cytokines from T helper 2 cell (Th2) such as interleukin (IL)-4, IL-5, and IL-13, is a potential mechanism underlying SAD. Research on small airway function in asthma is limited. We aimed to explore the correlation between small airway function and respiratory symptoms and comorbidity in T2 and non-T2 asthma.

Methods

Derived from the National Health and Nutrition Examination Survey (NHANES), our study encompassed 2,420 asthma patients aged 6 - 79 years, including pulmonary function (PF) data such as forced expiratory flow between 25% and 75% of forced vital capacity (FEF25-75), forced expiratory volume in 1 second (FEV1), forced expiratory volume in 3 seconds (FEV3), forced expiratory volume in 6 seconds (FEV6), and forced vital capacity (FVC). To evaluate the small airway function, we calculated z-scores for FEF25-75, FEF25-75/FVC, FEV1/FEV6, and FEV3/FEV6. Logistic regression determined the adjusted odds ratios (aORs) for symptoms and comorbidity.

Results

FEF25-75, FEV1/FEV6, and FEV3/FEV6 correlated with asthmatic symptoms. FEF25-75 had the strongest association with wheezing or whistling attacks. An increase of 1 standard deviations (SD) in FEF25-75 reduced recurrent wheezing (aOR: 0.70; 95% confidence intervals (95% CIs): 0.65 - 0.76) and severe attacks (aOR: 0.67; 95% CI: 0.62 - 0.94). These indices were also linked to dry cough and hay fever, particularly FEV3/FEV6 reducing hay fever risk (aOR: 0.70; 95% CI: 0.55 - 0.91) in non-T2 asthma. FEF25-75/FVC related to persistent (aOR: 0.78; 95% CI: 0.72 - 0.84) and severe attacks (aOR: 1.14; 95% CI: 1.08 - 1.22) in non-T2 groups. Lower indices combined with T2 exposure raised severe attack risk.

Conclusions

In this nationwide study, small airway function correlated with symptom onset, especially in T2 asthma. Small airway injury differed between T2 and non-T2 asthma. Prospective research is needed to establish reference values.

Identification of exhaled volatile organic compounds that characterize asthma phenotypes: A J-VOCSA study

BACKGROUND

Asthma is characterized by phenotypes of different clinical, demographic, and pathological characteristics. Identifying the profile of exhaled volatile organic compounds (VOCs) in asthma phenotypes may facilitate establishing biomarkers and understanding asthma background pathogenesis. This study aimed to identify exhaled VOCs that characterize severe asthma phenotypes among patients with asthma.

METHODS

This was a multicenter cross-sectional study of patients with severe asthma in Japan. Clinical data were obtained from medical records, and questionnaires were collected. Exhaled breath was sampled and subjected to thermal desorption gas chromatography-mass spectrometry (GC/MS).

RESULTS

Using the decision tree established in the previous nationwide asthma cohort study, 245 patients with asthma were divided into five phenotypes and subjected to exhaled VOC analysis with 50 healthy controls (HCs). GC/MS detected 243 VOCs in exhaled breath samples, and 142 frequently detected VOCs (50% of all samples) were used for statistical analyses. Cluster analysis assigning the groups with similar VOC profile patterns showed the highest similarities between phenotypes 3 and 4 (early-onset asthma phenotypes), followed by the similarities between phenotypes 1 and 2 (late-onset asthma phenotypes). Comparisons between phenotypes 1-5 and HC revealed 19 VOCs, in which only methanesulfonic anhydride showed p < 0.05 adjusted by false discovery rate (FDR). Comparison of these phenotypes yielded several VOCs showing different trends (p < 0.05); however, no VOCs showed p < 0.05 adjusted by FDR.

CONCLUSIONS

Exhaled VOC profiles may be useful for distinguishing asthma and asthma phenotypes; however, these findings need to be validated, and their pathological roles should be clarified.

Different Impacts of Traffic-Related Air Pollution on Early-Onset and Late-Onset Asthma

Background

Early-onset asthma (EOA) and late-onset asthma (LOA) are two distinct phenotypes. Air pollution has been associated with an increase in poorer asthma outcomes. The objective of this study was to examine the effects of traffic-related air pollution (TRAP) on asthma outcomes in EOA and LOA patients.

Methods

A cross-sectional study was conducted on 675 asthma patients (LOA: 415) recruited from a major medical center in Taiwan. The land-use regression (LUR) model was used to estimate the level of exposure to PM10, PM2.5, NO2, and O3 on an individual level. We investigated the association between TRAP and asthma outcomes in EOA and LOA patients, stratified by allergic sensitization status, using a regression approach.

Results

An increase in PM10 was associated with younger age of onset, increased asthma duration, and decreased lung function in EOA patients (p<0.05). An increase in PM10 was associated with older age of onset, and decreased asthma duration, eosinophil count, and Asthma Control Test (ACT) score in LOA patients. An increase in PM2.5 was associated with younger age of onset, increased asthma duration, decreased eosinophil count, and lung function in EOA patients (p<0.05). An increase in PM2.5 was associated with decreased lung function and ACT score in LOA patients. An increase in NO2 was associated with increased eosinophil count and decreased lung function in EOA patients (p<0.05). An increase in O3 was associated with decreased lung function in LOA patients (p<0.05). In addition, associations of TRAP with age of onset and eosinophil counts were mainly observed in both EOA and LOA patients with allergic sensitization, and an association with ACT was mainly observed in LOA patients without allergic sensitization.

Conclusion

The impact of TRAP on age of onset, eosinophil count, and lung function in EOA patients, and ACT in LOA patients, was affected by the status of allergic sensitization.

Dietary carbohydrate types, genetic predisposition, and risk of adult-onset asthma: A longitudinal cohort study

We aimed to investigate the longitudinal associations among carbohydrate intake types, genetic predisposition, and risk adult onset asthma (AOA). A dataset of 96,487 participants from UK Biobank was included with 1830 cases of incident AOA during an average follow-up of 9.68 years. Participants with the highest intake of total sugar, free sugar, and fiber intake, as compared to those with the lowest intake of total sugar, free sugar, and fiber intake, showed a 17 % and 22 % increased risk of incident AOA, and a 16 % decreased risk of AOA, respectively. Substitution of 5 % energy from free sugars with 5 % energy from non-free sugars was associated with a significantly lower risk of AOA (Hazard Ratio [HR] = 0.93, 95 % Confidence Interval [CI]: 0.88, 0.99). Participants with high genetic risk and the highest intake of free sugar showed a 112 % (HR = 2.12, 95%CI: 1.68, 2.68) increased risk of incident AOA. Participants with low genetic risk and highest intake of fiber showed a 50 % (HR = 0.50, 95%CI: 0.39, 0.64) reduced risk of AOA. This study highlights the critical role of carbohydrate types in AOA prevention, with an emphasis on reduced free sugar, moderate non-free sugar, and increased fiber intake.

Moderate-High Blood Eosinophilia Is Associated with Increased Hospitalization and Other Asthma Comorbidities

(1) Background: Eosinophilia has traditionally been linked to eosinophilic asthma, for which it is the gold-standard prognostic biomarker. However, the association between eosinophilia and the presence of other diseases and comorbidities is yet unclear. (2) Methods: For this retrospective study, we reviewed the electronic medical records of 49,909 subjects with blood eosinophilia to gather data on the presence of asthma, COPD, sleep apnea, tuberculosis, dyslipidemia, hypertension, and other cardiovascular diseases and severe CRSwNP among these subjects. Demographic features including age, sex, and smoking habits were collected, as well as the number of hospitalizations and emergency department visits. T-tests, ANOVA, Fisher test, and logistic regression models were used. (3) Results: For all age groups studied, eosinophilia was significantly more prevalent among asthmatic subjects than nonasthmatics, especially in patients also presenting CRSwNP, hypertension, and dyslipidemia. The likelihood of developing asthma, COPD, and CRSwNP, and hospitalization, was increased when BEC was above 600 eosinophils/μL. The association between asthma, CRSwNP, and BEC was corroborated by multiple logistic regressions models. (4) Conclusions: We demonstrated the association of having over 600 blood eosinophils/μL with a higher number of hospitalizations and comorbidities (CRSwNP and COPD), which proves that BEC is a highly useful parameter to consider in subjects who present blood eosinophilia.

Life's Essential 8, genetic predisposition, and risk of incident adult-onset asthma: a prospective cohort study

BACKGROUND

Adult-onset asthma (AOA) and cardiovascular diseases shared common risk factors and similar pathophysiologic resemblances. The American Heart Association (AHA) unveiled the life's essential 8 (LE8) to promote cardiovascular health (CVH). This study aimed to assess the overall impact of LE8 implementation on AOA prevention.

METHODS

According to the guideline of AHA's Construct of CVH in 2022, LE8 score was calculated from 8 health status concerning diet, physical activity, nicotine exposure, sleep health, body mass index, blood lipids, blood glucose, and blood pressure. Cox proportional-hazards models were used to estimate effect sizes of associations between CVH, asthma genetic risk, and risk of incident AOA in participants selected from the UK Biobank study.

RESULTS

A total of 6180 incident AOA cases occurred in 249,713 participants during an average of 11.60 y' follow-up. A higher LE8 score was associated with a lower risk of incident AOA with a significant linear trend (P < 0.0001). Every standard deviation increment of LE8 was associated with a 17% (HR: 0.83; 95% CI: 0.81, 0.85) lower risk of incident AOA. Compared with participants with low-CVH score, participants with moderate (HR: 0.72; 95% CI: 0.67, 0.78) and high CVH scores (HR: 0.52; 95% CI: 0.47, 0.58) were associated with a lower risk of incident AOA (P-trend < 0.0001). No significant multiplicative or additive interaction was found between LE8 score and genetic risks. Stratified analysis showed a consistent association between CVH and risk of incident AOA across different asthma polygenic risk score (PRS) levels. Compared with participants with high PRS and low CVH, participants with low PRS and high CVH experienced the lowest risk (HR: 0.28; 95% CI: 0.23, 0.34) of incident AOA.

CONCLUSIONS

Our findings suggest that maintaining optimal CVH should be recommended as a preventive strategy for AOA, regardless of their asthma genetic risks.

Asthma and Rhinitis Through the Lifespan of Nonpregnant Women

Increasingly, clinical practice guidelines advocate a precision medicine-based approach to care for asthma. This focus requires knowledge of not only different asthma phenotypes and their associated biomarkers but also sex and gender differences through the lifespan. Evidence continues to build in favor of different lifetime prevalence, clinical presentations, responses to management, and long-term prognosis of asthma. Women transition through many biological and psychosocial phases in their lives, all of which may interact with, and influence, their health and well-being. Historically, explanations have focused on hormonal effects on asthma in reproductive life, but a greater understanding of mechanisms starting before birth and changing over a lifetime is now possible, with immunologic, inflammatory, and hormonal factors playing a role. This article describes the evidence for the differences in asthma and rhinitis between men and women at different stages of life, the potential underlying mechanisms that contribute to this, and the implications for management and research. Future research studies should systematically report sex differences in asthma so that this knowledge can be used to develop a personalized approach to care, to achieve best possible outcomes for all.

The associations between asthma and common comorbidities: a comprehensive Mendelian randomization study

Background

Asthma is a chronic respiratory disease and is often associated with multiple comorbidities. The causal relationship between asthma and these comorbidities is still unclear. This study aimed to investigate the association between genetically predicted asthma and common comorbidities.

Methods

After searching PubMed and GWAS summary statistics, we identified 26 comorbidities of asthma. The causal relationship between asthma and comorbidities was assessed in two independent GWASs by bidirectional Mendelian randomization, followed by validation of the results using a multivariate Mendelian randomization analysis and several sensitivity analyses.

Results

In the bidirectional Mendelian randomization analysis, chronic sinusitis [odds ratio (OR) = 1.54, p = 1.40 × 10-5], atopic dermatitis (OR = 1.36, p = 9.37 × 10-21), allergic conjunctivitis (OR = 2.07, p = 4.32 × 10-6), and allergic rhinitis (OR = 1.53, p = 5.20 × 10-6) were significantly associated with increased asthma risk. Hyperthyroidism (OR = 1.12, p = 0.04) had a potential increased risk for asthma. For the reverse direction, asthma showed significant associations with an increased risk of chronic obstructive pulmonary disease (OR = 1.24, p = 2.25 × 10-9), chronic sinusitis (OR = 1.61, p = 5.25 × 10-21), atopic dermatitis (OR = 2.11, p = 1.24 × 10-24), allergic conjunctivitis (OR = 1.65, p = 6.66 × 10-35), allergic rhinitis (OR = 1.90, p = 2.38 × 10-57), and a potential higher risk of allergic urticaria (OR = 1.25, p = 0.003).

Conclusion

This study suggested a significant bidirectional association of chronic sinusitis, atopic dermatitis, allergic conjunctivitis, and allergic rhinitis with asthma. In addition, hyperthyroidism was associated with an increased risk of asthma and asthma increased the risk of chronic obstructive pulmonary disease and allergic urticaria.

Severity of adult-onset asthma - a matter of blood neutrophils and severe obesity

BACKGROUND

Adult-onset asthma is associated with a poor treatment response. The aim was to study associations between clinical characteristics, asthma control and treatment in adult-onset asthma.

METHODS

Previous participants within the population-based Obstructive Lung Disease in Northern Sweden studies (OLIN) were in 2019-2020 invited to clinical examinations including structured interviews, spirometry, fractional exhaled nitric oxide (FeNO), skin prick test and blood sampling. In total, n = 251 individuals with adult-onset asthma (debut >15 years of age) were identified. Uncontrolled asthma was defined according to ERS/ATS and treatment step according to GINA (2019).

RESULTS

Among individuals with uncontrolled asthma (34%), severe obesity (16.3% vs 7.9%, p = 0.041) and elevated levels of blood neutrophils, both regarding mean level of blood neutrophils (4.25*109/L vs 3.67*109/L, p = 0.003), and proportions with ≥4*109/L (49.4% vs 33.3%, p = 0.017) and ≥5*109/L (32.1% vs 13.7%, p < 0.001) were more common than among those with controlled asthma. Adding the dimension of GINA treatment step 1-5, individuals with uncontrolled asthma on step 4-5 treatment had the highest proportions of blood neutrophils ≥5*109/L (45.5%), severe obesity (BMI≥35, 26.1%), dyspnea (mMRC≥2) (34.8%), and most impaired lung function in terms of FEV1%<80% of predicted (42.9%), FEV1

CONCLUSION

This study indicates that in adult-onset asthma, primarily non-type-2 characteristics such as obesity and blood neutrophils associate with poor asthma control and higher doses of inhaled corticosteroids.

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Key Words

• Body mass index
• Eosinophils
• Epidemiology
• Follow-up studies
• Neutrophils
• Sweden

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MESH Headings

• Humans
• Adult
• Neutrophils
• Obesity, Morbid/complications
• Nitric Oxide/therapeutic use
• Asthma/drug therapy
• Eosinophils
• Obesity/complications

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Affiliation(s)

Sofia Winsa-Lindmark Umeå University, Department of Public Health and Clinical Medicine, Section for Sustainable Health/The OLIN Unit, Sweden.
Caroline Stridsman Umeå University, Department of Public Health and Clinical Medicine, The OLIN Unit, Sweden
Axel Sahlin Umeå University, Department of Public Health and Clinical Medicine, Section for Sustainable Health/The OLIN Unit, Sweden
Linnea Hedman Umeå University, Department of Public Health and Clinical Medicine, Section for Sustainable Health/The OLIN Unit, Sweden
Nikolai Stenfors Umeå University, Department of Public Health and Clinical Medicine, The OLIN Unit, Sweden
Tomi Myrberg Umeå University, Department of Surgical and Perioperative Sciences, Anesthesiology and Intensive Care Medicine, Sweden
Anne Lindberg Umeå University, Department of Public Health and Clinical Medicine, The OLIN Unit, Sweden
Eva Rönmark Umeå University, Department of Public Health and Clinical Medicine, Section for Sustainable Health/The OLIN Unit, Sweden
Helena Backman Umeå University, Department of Public Health and Clinical Medicine, Section for Sustainable Health/The OLIN Unit, Sweden

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Setting up and assessing a therapeutic education program for asthmatic patients

BACKGROUND

Asthma is a major public health issue. It remains uncontrolled, despite the availability of effective treatments. Appropriate education programs are required to improve the situation. The study aims to design and assess an educational program based on asthma patients' perceived needs.

MATERIALS AND METHODS

A cross-sectional prospective study was conducted in the pulmonology department of the Hassan II University Hospital in Fez. A convenience sample of asthma patients, whether hospitalized or not, was recruited. Two hundred and twenty adult asthma patients completed an educational needs survey (ENS). An asthma knowledge questionnaire for adult patients was used to assess the program on the criterion of improving asthma knowledge. Data collected by ENS was analyzed by standard descriptive statistics. The Student's T test for paired samples was used to compare the means of the Asthma Knowledge Questionnaire scores before and after therapeutic education.

RESULTS

Most patients were married and residing in urban areas. The illiteracy rate was 50%. One patient was a regular smoker. 125 patients (56.82%) reported non-compliance to treatment. The pathophysiology of asthma (chronic airway inflammation, bronchial hyperreactivity, and bronchial obstruction), causes and complications, treatment (inhalation technique), asthma attacks and environmental management, lifestyle, and psychological support were the patients' main perceived educational needs. Based on these findings, an instructional program was created and evaluated with 30 patients. After the program, asthma knowledge increased significantly.

CONCLUSION

Our results suggest that an educational intervention can improve asthma knowledge.

Cluster Analysis of Finnish Population-Based Adult-Onset Asthma Patients

BACKGROUND

Phenotypes of adult asthma have been identified in previous studies but rarely in population-based settings.

OBJECTIVE

To identify clusters of adult-onset asthma in a Finnish population-based study on subjects born before 1967.

METHODS

We used population-based data from 1350 asthmatics with adult-onset asthma (Adult Asthma in Finland) from Finnish national registers. Twenty-eight covariates were selected based on literature. The number of covariates was reduced by using factor analysis before cluster analysis.

RESULTS

Five clusters (CLU1-CLU5) were identified, 3 clusters with late-onset adult asthma (onset ≥40 years) and 2 clusters with onset at earlier adulthood (<40 years). Subjects in CLU1 (n = 666) had late-onset asthma and were nonobese, symptomatic, and predominantly female with few respiratory infections during childhood. CLU2 (n = 36) consisted of subjects who had earlier-onset asthma, were predominantly female, obese with allergic asthma, and had recurrent respiratory infections. Subjects in CLU3 (n = 75) were nonobese, older, and predominantly men with late-onset asthma, smoking history, comorbidities, severe asthma, least allergic diseases, low education, many siblings, and childhood in rural areas. CLU4 (n = 218) was a late-onset cluster consisting of obese females with comorbidities, asthma symptoms, and low education level. Subjects in CLU5 (n = 260) had earlier onset asthma, were nonobese, and predominantly allergic females.

CONCLUSIONS

Our population-based adult-onset asthma clusters take into account several critical factors such as obesity and smoking, and identified clusters that partially overlap with clusters identified in clinical settings. Results give us a more profound understanding of adult-onset asthma phenotypes and support personalized management.

Extracellular Vesicles (EVs) as Crucial Mediators of Cell-Cell Interaction in Asthma

Asthma is the most common chronic respiratory disorder worldwide and accounts for a huge health and economic burden. Its incidence is rapidly increasing but, in parallel, novel personalized approaches have emerged. Indeed, the improved knowledge of cells and molecules mediating asthma pathogenesis has led to the development of targeted therapies that significantly increased our ability to treat asthma patients, especially in severe stages of disease. In such complex scenarios, extracellular vesicles (EVs i.e., anucleated particles transporting nucleic acids, cytokines, and lipids) have gained the spotlight, being considered key sensors and mediators of the mechanisms controlling cell-to-cell interplay. We will herein first revise the existing evidence, mainly by mechanistic studies in vitro and in animal models, that EV content and release is strongly influenced by the specific triggers of asthma. Current studies indicate that EVs are released by potentially all cell subtypes in the asthmatic airways, particularly by bronchial epithelial cells (with different cargoes in the apical and basolateral side) and inflammatory cells. Such studies largely suggest a pro-inflammatory and pro-remodelling role of EVs, whereas a minority of reports indicate protective effects, particularly by mesenchymal cells. The co-existence of several confounding factors-including technical pitfalls and host and environmental confounders-is still a major challenge in human studies. Technical standardization in isolating EVs from different body fluids and careful selection of patients will provide the basis for obtaining reliable results and extend their application as effective biomarkers in asthma.

Epidemiology of Asthma: Prevalence and Burden of Disease

Asthma, a common airway disease, results in a significant burden to both patients and society worldwide. Yet, despite global political commitment backed by the United Nations, progress to reduce the burden of asthma remains inadequate. This is particularly true in low-income countries. To date, progress has been delayed by the lack of uniform data collection, imperfect surveillance methods, inadequate resources, poor access to effective therapies, substandard asthma education, ineffective governmental policies, rapid urbanization, progressive increase in asthma prevalence, increased life expectancy and obesity rates worldwide, asthma heterogeneity and disease complexity, smoking, and environmental exposures to allergens and pollution. A thorough understanding of the challenges facing the international community is essential to define future strategies to improve the burden of asthma.