Phenotypes, Risk Factors, and Mechanisms of Adult-Onset Asthma

The impact of high-salt diet on asthma in humans and mice: Effect on specific T-cell signatures and microbiome

BACKGROUND

The rise in asthma has been linked to different environmental and lifestyle factors including dietary habits. Whether dietary salt contributes to asthma incidence, remains controversial. We aimed to investigate the impact of higher salt intake on asthma incidence in humans and to evaluate underlying mechanisms using mouse models.

METHODS

Epidemiological research was conducted using the UK Biobank Resource. Data were obtained from 42,976 participants with a history of allergies. 24-h sodium excretion was estimated from spot urine, and its association with asthma incidence was assessed by Cox regression, adjusting for relevant covariates. For mechanistic studies, a mouse model of mite-induced allergic airway inflammation (AAI) fed with high-salt diet (HSD) or normal-salt chow was used to characterize disease development. The microbiome of lung and feces (as proxy for gut) was analyzed via 16S rRNA gene based metabarcoding approach.

RESULTS

In humans, urinary sodium excretion was directly associated with asthma incidence among females but not among males. HSD-fed female mice displayed an aggravated AAI characterized by increased levels of total IgE, a TH2-TH17-biased inflammatory cell infiltration accompanied by upregulation of osmosensitive stress genes. HSD induced distinct changes in serum short chain fatty acids and in both gut and lung microbiome, with a lower Bacteroidetes to Firmicutes ratio and decreased Lactobacillus relative abundance in the gut, and enriched members of Gammaproteobacteria in the lung.

CONCLUSIONS

High dietary salt consumption correlates with asthma incidence in female adults with a history of allergies. Female mice revealed HSD-induced T-cell lung profiles accompanied by alterations of gut and lung microbiome.

Pre-asthma: a useful concept? A EUFOREA paper. Part 2-late onset eosinophilic asthma

The concept of pre-diabetes has led to provision of measures to reduce disease progression through identification of subjects at risk of diabetes. We previously considered the idea of pre-asthma in relation to allergic asthma and considered that, in addition to the need to improve population health via multiple measures, including reduction of exposure to allergens and pollutants and avoidance of obesity, there are several possible specific means to reduce asthma development in those most at risk (pre- asthma). The most obvious is allergen immunotherapy (AIT), which when given for allergic rhinitis (AR) has reasonable evidence to support asthma prevention in children (2) but also needs further study as primary prevention. In this second paper we explore the possibilities for similar actions in late onset eosinophilic asthma.

Adult-onset asthma, allergy, and aspirin hypersensitivity associate with self-reported food avoidance

Background

The adoption of avoidance diets by adult-onset asthmatics has not previously been studied. We hypothesized that avoidance diets would associate with adult-onset asthma, allergy, and aspirin-exacerbated respiratory disease (AERD).

Methods

A total of 1247 subjects with adult-onset asthma (age range: 31-91) from the Finnish national registry, and age- and sex-matched controls (n = 1970) participated in a questionnaire study in 1997. We estimated the association between asthma/allergy/AERD and avoidance diets, adjusting for potential confounding factors and validated the results in two retrospective cohorts of 5080 rhinitis/rhinosinusitis patients and 167 AERD patients from 2019 to 2020.

Results

The presence of asthma positively associated with adoption of any avoidance diet (adjusted OR [CI95%] 1.24 [1.02-1.51], p = 0.029) as did allergic disease and self-reported AERD within the asthmatic group (1.79 [1.29-2.48], p = 0.001 and 1.69 [1.15-2.49], p = 0.007, respectively). Asthmatics and allergic asthmatics were more likely to report avoidance of fish, fruits and vegetables, and spices (p ≤ 0.03) compared to controls and non-allergic asthmatics. The adjusted OR for multiple diets among AERD patients was 2.57 [1.34-4.95] p = 0.005. In the validation, 26.2% of the allergic asthmatics and 10.8% of AERD patients had documented avoidance diets.

Conclusions

Our study shows a positive association between avoidance diets and adult-onset asthma, and with allergic disease or AERD within asthmatic patients. Although we lack information on the reason patients chose to observe a specific diet, our results reinforce the importance of asking patients about their diet and if needed, giving dietary advice for adult asthma patients to help them avoid the adoption of unnecessarily restrictive diets.

Allergen skin test responses in broad U.S. asthma population in those with and without rhinitis

Background: Asthma and allergic rhinitis are pathologically interlinked conditions. Despite skin testing (ST) being pivotal for evaluating allergic sensitization, U.S. data that date back to 1960s on ST reactivity patterns in subjects with asthma remain sparse. Objective: The purpose of this study was to elucidate seasonal, perennial ST responses, and their relationship with asthma severity, early versus late onset disease, and immunoglobulin E (IgE) levels. Methods: Five hundred patients with asthma were randomly selected from the National Jewish Health electronic medical record over a 3-year span. Demographic, clinical, and allergen ST reactivity data for a battery of seasonal and perennial allergens were procured, including total IgE levels, asthma onset, and severity, by using t-tests, χ² tests, and Analysis of Variance (ANOVA), patterns of reactivity were assessed for overall, seasonal, and perennial allergens in relation to IgE levels, asthma onset, and severity. Results: Of the 500 patients, 398 were analyzed. 63.3% were women, 50.1% had adult-onset asthma, and 86.1% had rhinitis; 75.3% tested positive to one or more allergens, with men demonstrating higher overall (p = 0.039) and perennial (p = 0.035) sensitization. ST reactivity varied based on the presence of rhinitis for seasonal (p = 0.028) but not perennial (p = 0.733) allergens. Asthma severity was not significantly associated with ST reactivity (p > 0.10). ST positivity for perennial (p < 0.001) but not seasonal (p = 0.128) allergens was higher in childhood-onset asthma versus adult-onset asthma despite both groups having a large percentage of reactors. Elevated IgE levels correlated with ST reactivity (p < 0.01). Conclusion: Our study represents a unique comprehensive evaluation of ST reactivity in a U.S. asthma population, which is lacking in the literature, when factoring in asthma onset, severity, and IgE levels. Our findings underscore the importance of allergen sensitization in asthma, regardless of severity, concurrent rhinitis symptoms, or asthma onset, which challenge some of the prevailing assumptions about the relationship between allergen sensitization and asthma onset.

The Impact of Air Pollution on Asthma Severity among Residents Living near the Main Industrial Complex in Oman: A Cross-Sectional Study

BACKGROUND

Asthma is a widespread chronic respiratory disease that poses a significant public health challenge. The current study investigated the associations between air pollution and asthma severity among individuals residing near the Sohar industrial port (SIP) in Oman. Despite the presence of multiple major industrial complexes in Oman, limited knowledge regarding their impact on respiratory health is accredited. Hence, the primary objective of this study is to offer valuable insights into the respiratory health consequences of industrial air pollution in Al Batinah North.

METHODS

The state health clinics' records for patient visits related to asthma were collected for the timeframe spanning 2014 to 2022. Exposure was defined as the distance from the SIP, Majan Industerial Area (MIA), and Sohar Industerial Zone (SIZ) to determine high-, intermediate-, and low-exposure zones (<6 km, 6-12 km and >12 km, respectively). Exposure effect modifications by age, gender, and smoking status were also examined.

RESULTS

The conducted cross-sectional study of 410 patients (46.1% males and 53.9% females) living in over 17 areas around SIP revealed that 73.2% of asthmatics were under 50 years old, with severity significantly associated with closeness to the port. Risk ratios were estimated to be (RR:2.42; CI95%: 1.01-5.78), (RR:1.91; CI95%: 1.01-3.6), and (RR:1.68; CI95%: 0.92-3.09) for SIP, MIP, and SIZ areas, respectively, compared to the control area. Falaj Al Qabail (6.4 km) and Majees (6 km) had the highest number of asthma patients (N 69 and N 72) and highest percentages of severe asthma cases among these patients (28% and 24%) with significant risk ratios (RR:2.97; CI95%: 1.19-7.45 and RR:2.55; CI95%: 1.00-6.48), correspondingly. Moreover, severe asthma prevalence peaked in the 25-50 age group (RR:2.05; CI95%: 1.26-3.33), and this linkage between asthma and age was much more pronounced in males than females. Smoking and exposure to certain contaminants (dust and smoke) also increased the risk of severe asthma symptoms, but their effects were less important in the high-risk zone, suggesting much more important risk factors. A neural network model accurately predicted asthma risk (94.8% accuracy), with proximity to SIP as the most influential predictor.

CONCLUSIONS

This study highlights the high asthma burden near SIP, linked to port proximity, smoking, and wind direction as major risk factors. These findings inform vital public health policies to reduce air pollution and improve respiratory health in the region, prompting national policy review.

The Exploitation of the Glycosylation Pattern in Asthma: How We Alter Ancestral Pathways to Develop New Treatments

Asthma has reached epidemic levels, yet progress in developing specific therapies is slow. One of the main reasons for this is the fact that asthma is an umbrella term for various distinct subsets. Due to its high heterogeneity, it is difficult to establish biomarkers for each subset of asthma and to propose endotype-specific treatments. This review focuses on protein glycosylation as a process activated in asthma and ways to utilize it to develop novel biomarkers and treatments. We discuss known and relevant glycoproteins whose functions control disease development. The key role of glycoproteins in processes integral to asthma, such as inflammation, tissue remodeling, and repair, justifies our interest and research in the field of glycobiology. Altering the glycosylation states of proteins contributing to asthma can change the pathological processes that we previously failed to inhibit. Special emphasis is placed on chitotriosidase 1 (CHIT1), an enzyme capable of modifying LacNAc- and LacdiNAc-containing glycans. The expression and activity of CHIT1 are induced in human diseased lungs, and its pathological role has been demonstrated by both genetic and pharmacological approaches. We propose that studying the glycosylation pattern and enzymes involved in glycosylation in asthma can help in patient stratification and in developing personalized treatment.

Asthma prevalence among United States population insights from NHANES data analysis

Asthma is a prevalent respiratory condition that poses a substantial burden on public health in the United States. Understanding its prevalence and associated risk factors is vital for informed policymaking and public health interventions. This study aims to examine asthma prevalence and identify major risk factors in the U.S.

POPULATION

Our study utilized NHANES data between 1999 and 2020 to investigate asthma prevalence and associated risk factors within the U.S.

POPULATION

We analyzed a dataset of 64,222 participants, excluding those under 20 years old. We performed binary regression analysis to examine the relationship of demographic and health related covariates with the prevalence of asthma. The study found that asthma affected 8.7% of the U.S.

POPULATION

Gender emerged as a significant factor, with 36.0% of asthma patients being male and 64.0% female (p < 0.001). Individuals aged 60 and older having the highest asthma prevalence at 34.0%. Non-Hispanic whites had the highest prevalence at 46.4%, followed by non-hispanic blacks at 26.0%. In contrast, Mexican Americans and other hispanic individuals had lower rates, at 9.6% and 9.0%, respectively. Females were 1.76 times more likely to have asthma than males (p < 0.001). Obese individuals had a 1.74 times higher likelihood of current asthma compared to underweight individuals (p < 0.001). Notably, both Non-Hispanic Whites and Non-Hispanic Blacks showed higher odds of current asthma compared to Mexican Americans (with adjusted odds ratios of 2.084 and 2.096, respectively, p < 0.001). The research findings indicate that asthma is prevalent in 8.7% of the U.S.

POPULATION

Our study highlights that individuals who are female, have low income, are obese, and smoke have the highest likelihood of being affected by asthma. Therefore, public health policies should prioritize addressing these risk factors in their preventive strategies.

Association between asthma, obesity, and metabolic syndrome in adolescents and young adults

BACKGROUND

The association of asthma and metabolic syndrome (MetS) among adolescents and young adults (AYAs) remains unclear, as well as the role of obesity in this relationship.

METHODS

AYAs aged 12-25 years who participated in the 2011-2020 National Health and Nutrition Examination Survey were included in this cross-sectional analysis. The moderating effect of obesity (age- and sex-adjusted body mass index ≥ 95th%ile for adolescents or ≥ 30 kg/m2 for adults) on asthma and MetS were evaluated in four groups: 1) both asthma and obesity; 2) asthma and no obesity; 3) obesity and no asthma; and 4) healthy controls with no obesity/asthma.

RESULTS

A total of 7,709 AYAs (53.9% aged 12-18 years, 51.1% males, and 54.4% non-Hispanic White) were included in this analysis. 3.6% (95% CI 2.8-4.3%) had obesity and asthma, 7.6% (95% CI 6.8-8.4%) had asthma and no obesity, 21.4% (95% CI 19.6-23.2%) had obesity and no asthma, and 67.4% (95% CI 65.4-69.4%) had neither obesity nor asthma. The estimated prevalence of MetS was greater among those with both obesity and asthma versus those with only asthma (4.5% [95% CI 1.7-7.3%] vs. 0.2% [95% CI 0-0.5%], p < 0.001). Compared to healthy controls, those with both obesity and asthma had ∼10 times higher odds of having MetS (aOR 10.5, 95% CI 3.9-28.1).

CONCLUSIONS

Our results show the association between MetS and asthma is stronger in AYAs with BMI-defined obesity. Efforts to prevent and treat obesity may reduce MetS occurrence in AYAs with asthma.

Agreement between self-reported and registered age at asthma diagnosis in Finland

INTRODUCTION

In epidemiological studies, the age at asthma onset is often defined by patients' self-reported age at diagnosis. The reliability of this report might be questioned. Our objective was to evaluate the agreement between self-reported and registered age at asthma diagnosis and assess features contributing to the agreement.

METHODS

As part of the FinEsS respiratory survey in 2016, randomly selected population samples of 13,435 from Helsinki and 8000 from Western Finland were studied. Self-reported age at asthma diagnosis was compared to age at asthma diagnosis registered in the Finnish register on special reimbursement for asthma medication. The reimbursement right is based on lung function criteria according to GINA and Finnish guidelines. If the difference was less than 5 years, self-reported diagnosis was considered reliable. Features associated with the difference between self-reported and registered age at asthma diagnosis were evaluated.

RESULTS

Altogether 197 subjects from Helsinki and 144 from Western Finland were included. Of these, 61.9% and 77.8%, respectively, reported age at diagnosis reliably. Median difference between self-reported and registered age at diagnoses was - 2.0 years (IQR - 9.0 to 0) in Helsinki and - 1.0 (IQR - 4.3 to 0) in Western Finland indicating earlier self-reported age at diagnosis. More reliable self-report was associated with non-allergic subjects and subjects who reported having asthma diagnosis more recently.

CONCLUSIONS

Agreement between self-reported and registered age at asthma diagnosis was good especially with adult-onset asthma patients. Poor agreement in early-onset asthma could be related to delay in registration due to reimbursement criteria.

Association between interleukin-6-174G/C gene polymorphism and asthma severity: exploring the role of total serum IgE, blood eosinophils, and FeNO as markers of type 2 inflammation

BACKGROUND

While a connection has been established between serum interleukin-6 (IL-6) levels and the IL-6 gene (- 174G/C) polymorphism in allergic diseases such as asthma, its specific association with severe asthma remains unexplored. This study examined the relationship between the IL-6 (- 174G/C) gene polymorphism and mild and severe asthma, focusing on its influence on type 2 inflammation.

METHODS

Our study comprised 98 patients with mild asthma and 116 with severe asthma. Additionally, we recruited 121 healthy participants to serve as controls for comparative analyses. The IL-6 gene (- 174G/C) polymorphism was assessed utilizing the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method.

RESULTS

In our study, the risk of mild asthma exhibited a significant fourfold increase in individuals with the GG genotype pattern compared to healthy controls, yielding an odds ratio (OR) of 4.4 (p < 0.001). Conversely, we found no significant correlation between the IL-6 - 174G/C gene polymorphism and severe asthma when compared to the healthy control group. However, a noteworthy pattern emerged when we compared subgroups of mild and severe asthma. The risk of severe asthma increased fivefold in individuals with the GC polymorphism pattern, with an OR of 4.99 (p < 0.001), while the likelihood of mild asthma showed a similar fourfold increase with the GG polymorphism pattern, OR = 4.4 (p < 0.001). Consequently, we observed a significantly higher frequency of the C allele in patients with severe asthma, whereas the G allele was more prevalent in individuals with mild asthma (p = 0.05). Additionally, the correlation between markers of type 2 inflammation and the dominant model of the IL-6 gene -174G/C polymorphism (CC + CG vs GG) revealed a significant increase in total serum immunoglobulin E (IgE), Blood Eosinophil Counts (BEC), and Fractional Exhaled Nitric Oxide (FeNO) levels in asthmatic patients with the CC + CG gene pattern compared to those with GG, with p-values of 0.04, 0.03, and 0.04, respectively. Furthermore, after adjusting for other risk factors, the likelihood of developing severe asthma increased from fourfold to eightfold, with an OR of 8.12 (p = 0.01) with (CC + CG) gene pattern. Other predictors for severe asthma included older age and childhood-onset disease (OR = 1.13 and 19.19, p < 0.001). Allergic rhinitis (AR) and nasal polyps (NP) also demonstrated a substantial association with an increased risk of severe asthma, with odds ratios of 5 and 32.29 (p = 0.01 and < 0.001), respectively. Additionally, elevated Body Mass Index (BMI), BEC, and FeNO were linked to severe asthma, with ORs of 1.11, 1.00, and 1.04, respectively (p = 0.04, 0.05, and 0.001).

CONCLUSION

This study illuminated the intricate relationship between the IL-6 gene polymorphism, type 2 inflammation markers, and diverse risk factors in shaping asthma severity. As a significant association between the GG polymorphism of the IL-6 gene (- 174G/C) and mild asthma was found, while possessing at least one C allele, whether in a homozygous (CC) or heterozygous (CG) combination, independently predicts the likelihood of severe asthma.

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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Age at asthma diagnosis and onset of symptoms among adults with allergic and non-allergic asthma

Background

Childhood-onset allergic asthma is the best-known phenotype of asthma. Adult-onset asthma, also an important entity, is instead often shown to be more non-allergic. There is still a lack of studies concerning the association of allergies and age at asthma onset from childhood to late adulthood. The aim of the study was to assess the age at onset of asthma symptoms and age at asthma diagnosis among adults with allergic and non-allergic asthma.

Methods

Questionnaires were sent to 2000 randomly selected Finnish adults aged 18-80 years who were dispensed medication for obstructive airway diseases during the previous year. The corrected sample size was 1978 subjects after exclusion of non-analysable data. The response rate was 40.6%. Self-reported doctor-diagnosed asthma was considered allergic if a concomitant self-reported doctor-diagnosed pollen and/or animal allergy was reported with asthma symptoms upon allergen exposure.

Results

Of the 496 participants with asthma, 42.7% were considered to have allergic asthma. The median ages at asthma diagnosis and onset of asthma symptoms were 31 (IQR 17-46) and 20 (9.25-40) years in participants with allergic asthma and 49 (37.75-58) and 40.5 (30-50) years in participants with non-allergic asthma (p < 0.001), respectively. Of the participants with asthma diagnosed at ≥30 years of age, 18% of allergic and 7% of non-allergic participants reported having had asthma symptoms under 20 years of age.

Conclusions

Both the onset of symptoms and diagnosis occurred at a younger age among adults with allergic asthma than among those with non-allergic asthma. Only a minority of adults with non-allergic asthma had already had symptoms in younghood.

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.

Airway Microbiome Composition and Co-Occurrence Network Are Associated with Inflammatory Phenotypes of Asthma

INTRODUCTION

The composition and co-occurrence network of the airway microbiome might influence the asthma inflammatory phenotype. Airway microbiota change with asthma phenotypes, and the structure of the bacterial community in the airway might differ between different asthma inflammatory phenotypes and may also influence therapy results. Identifying airway microbiota can help to investigate the role that microbiota play in the asthma inflammatory process.

METHODS

Induced sputum from 55 subjects and 12 healthy subjects from Beijing, China, was collected and analyzed for bacterial microbiota. Microbiome diversity, composition, co-occurrence networks, and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were predicted and compared between the study groups.

RESULTS

Significant differences in the sputum microbiome composition, co-occurrence network, and predicted functional pathways were observed between the two inflammatory phenotypes. Asthmatics in the low FeNO group exhibited lower α-diversity in the sputum microbiota and had higher abundance of the phylum Proteobacteria compared with that of the high FeNO group. The network in the high FeNO group was more "closed" and "connected" compared with that of the low FeNO group, and an alteration in the abundance of keystone species T. socranskii was found. Significantly different predicted metabolic subfunctions including nucleotide metabolism, lipid metabolism, energy metabolism, replication and repair, and drug resistance antimicrobial and carbohydrate metabolism between the two studied phenotypes were also observed.

CONCLUSION

Our findings confirm that the airway microbiota is associated with the asthma inflammation process. The differences in the airway microbiome composition and co-occurrence network may affect distinct asthma inflammatory phenotypes, suggesting the possibility that more targeted therapies could be applied based on the airway bacterial genera.

Exogenous female sex steroid hormones and new-onset asthma in women: a matched case-control study

BACKGROUND

Evidence on the role of exogenous female sex steroid hormones in asthma development in women remains conflicting. We sought to quantify the potential causal role of hormonal contraceptives and menopausal hormone therapy (MHT) in the development of asthma in women.

METHODS

We conducted a matched case-control study based on the West Sweden Asthma Study, nested in a representative cohort of 15,003 women aged 16-75 years, with 8-year follow-up (2008-2016). Data were analyzed using Frequentist and Bayesian conditional logistic regression models.

RESULTS

We included 114 cases and 717 controls. In Frequentist analysis, the odds ratio (OR) for new-onset asthma with ever use of hormonal contraceptives was 2.13 (95% confidence interval [CI] 1.03-4.38). Subgroup analyses showed that the OR increased consistently with older baseline age. The OR for new-onset asthma with ever MHT use among menopausal women was 1.17 (95% CI 0.49-2.82). In Bayesian analysis, the ORs for ever use of hormonal contraceptives and MHT were, respectively, 1.11 (95% posterior interval [PI] 0.79-1.55) and 1.18 (95% PI 0.92-1.52). The respective probability of each OR being larger than 1 was 72.3% and 90.6%.

CONCLUSIONS

Although use of hormonal contraceptives was associated with an increased risk of asthma, this may be explained by selection of women by baseline asthma status, given the upward trend in the effect estimate with older age. This indicates that use of hormonal contraceptives may in fact decrease asthma risk in women. Use of MHT may increase asthma risk in menopausal women.

Risk factors of NSAID-exacerbated respiratory disease: A population-based study

BACKGROUND

Asthma with NSAID-exacerbated respiratory disease (NERD) is associated with uncontrolled or severe asthma. NERD patients are more prone to severe allergic reactions and their asthma exacerbations lead to hospitalisations twice as often compared to patients with non-NERD-asthma. NERD patients are prone to recurrent nasal polyposis requiring frequent endoscopic sinus surgeries. However, the early risk factors of NERD are not fully understood. The aim was to identify risk factors of NERD among patients with adult-onset asthma.

METHODS

We used data from 1350 population-based adult asthmatics with adult-onset asthma from Finnish national registers. NERD was defined as self-reported wheeze or other typical respiratory symptoms after ingestion of NSAIDs. Thirty-six covariates covering several domains (personal characteristics, life-style, early life factors, asthma characteristics and multimorbidities) were selected based on literature and were studied in association with NERD using logistic regressions.

RESULTS

The study population included 153 (11.3%) asthmatics with NERD. Thirty-six covariates were entered in univariate logistic regression analysis, in which 23 were associated with NERD (p < 0.05). These variables were entered in a multivariable logistic regression model in which allergic respiratory symptoms, female sex, osteoarthritis, difficult asthma, nasal polyps, second-hand smoke exposure at home, having 3 or more older siblings and being overweight were significantly associated with asthma with NERD (p < 0.05). Overweight decreased the risk of NERD, other factors increased it.

CONCLUSION

According to our study, risk factors of NERD in part are associated with female sex, BMI, exposure to tobacco smoke, allergy, orthopaedic disorders and infection history, and their early recognition might thus be important to manage the burden of NERD.

Associations between Liver Enzymes, Lifestyle Risk Factors and Pre-Existing Medical Conditions in a Population-Based Cross-Sectional Sample

While alanine aminotransferase (ALT) and gamma-glutamyltransferase (GGT) enzymes are commonly used indicators of liver dysfunction recent studies have suggested that these may also serve as predictive biomarkers in the assessment of extrahepatic morbidity. In order to shed further light on the interactions between serum liver enzyme abnormalities, factors of lifestyle and health status we examined ALT and GGT activities in a population-based sample of 8743 adult individuals (4048 men, 4695 women from the National FINRISK 2002 Study, mean age 48.1 ± 13.1 years) with different levels of alcohol drinking, smoking, physical activity, body weight and the presence or absence of various pre-existing medical conditions. The assessments also included laboratory tests for inflammation, lipid status and fatty liver index (FLI), a proxy for fatty liver. The prevalence of ALT and GGT abnormalities were significantly influenced by alcohol use (ALT: p < 0.0005 for men; GGT: p <0.0005 for both genders), smoking (GGT: p <0.0005 for men, p =0.002 for women), adiposity (p < 0.0005 for all comparisons), physical inactivity (GGT: p <0.0005; ALT: p <0.0005 for men, p <0.05 for women) and coffee consumption (p <0.0005 for GGT in both genders; p <0.001 for ALT in men). The total sum of lifestyle risk factor scores (LRFS) influenced the occurrence of liver enzyme abnormalities in a rather linear manner. Significantly higher LRFS were observed in the subgroups of individuals with pre-existing medical conditions when compared with those having no morbidities (p <0.0005). In logistic regression analyses adjusted for the lifestyle factors, both ALT and GGT associated significantly with fatty liver, diabetes and hypertension. GGT levels also associated with coronary heart disease, angina pectoris, cardiac insufficiency, cerebrovascular disease, asthma and depression. Combinations of abnormal ALT and GGT activities significantly increased the odds for hypertension coinciding with abnormalities in biomarkers of inflammation, lipid status and FLI. The data indicates that ALT and GGT activities readily respond to unfavorable factors of lifestyle associating also with a wide array of pre-existing medical conditions. The data supports close links between both hepatic and extrahepatic morbidities and lifestyle risk factors and may open new insights on a more comprehensive use of liver enzymes in predictive algorithms for assessing mechanistically anchored disease conditions.

Symptoms of anxiety and depression in patients with persistent asthma: a cross-sectional analysis of the INSPIRERS studies

OBJECTIVES

Anxiety and depression are relevant comorbidities in asthma, but, in Portugal and Spain, data on this topic are scarce. We assessed, in patients with asthma, the frequency of anxiety and depression using the Hospital Anxiety and Depression Scale (HADS) and the European Quality of Life Five Dimension Questionnaire (EQ-5D); the level of agreement between these questionnaires, and the factors associated with these symptoms.

METHODS

This is a secondary analysis of the INSPIRERS studies. A total of 614 adolescents and adults with persistent asthma (32.6±16.9 years, 64.7% female) were recruited from 30 primary care centres and 32 allergy, pulmonology and paediatric clinics. Demographic and clinical characteristics, HADS and EQ-5D were collected. A score ≥8 on Hospital Anxiety and Depression Scale-Anxiety/Hospital Anxiety and Depression Scale-Depression or a positive answer to EQ-5D item 5 indicated the presence of these symptoms. Agreement was determined by Cohen's kappa. Two multivariable logistic regressions were built.

RESULTS

According to HADS, 36% of the participants had symptoms of anxiety and 12% of depression. According to EQ-5D, 36% of the participants had anxiety/depression. The agreement between questionnaires in identifying anxiety/depression was moderate (k=0.55, 95% CI 0.48 to 0.62). Late asthma diagnosis, comorbidities and female gender were predictors of anxiety/depression, while better asthma control, health-related quality of life and perception of health were associated with lower odds for anxiety/depression.

CONCLUSION

At least 1/3 of the patients with persistent asthma experience symptoms of anxiety/depression, showing the relevance of screening these disorders in patients with asthma. EQ-5D and HADS questionnaires showed a moderate agreement in the identification of anxiety/depression symptoms. The identified associated factors need to be further investigated in long-term studies.

Impact of multimorbidity patterns in hospital admissions: the case study of asthma

Most previous studies assessing multimorbidity in asthma assessed the frequency of individual comorbid diseases. We aimed to assess the frequency and clinical and economic impact of co-occurring groups of comorbidities (comorbidity patterns using the Charlson Comorbidity Index) on asthma hospitalizations. We assessed the dataset containing a registration of all Portuguese hospitalisations between 2011-2015. We applied three different approaches (regression models, association rule mining, and decision trees) to assess both the frequency and impact of comorbidities patterns in the length-of-stay, in-hospital mortality and hospital charges. For each approach, separate analyses were performed for episodes with asthma as main and as secondary diagnosis. Separate analyses were performed by participants' age group. We assessed 198340 hospitalizations in patients >18 years old. Both in hospitalizations with asthma as main or secondary diagnosis, combinations of diseases involving cancer, metastasis, cerebrovascular disease, hemiplegia/paraplegia, and liver disease displayed a relevant clinical and economic burden. In hospitalizations having asthma as a secondary diagnosis, we identified several comorbidity patterns involving asthma and associated with increased length-of-stay (average impact of 1.3-3.2 additional days), in-hospital mortality (OR range = 1.4-7.9) and hospital charges (average additional charges of 351.0 to 1025.8 Euro compared with hospitalizations without any registered Charlson comorbidity). Consistent results were observed with association rules mining and decision tree approaches. Our findings highlight the importance not only of a complete assessment of patients with asthma, but also of considering the presence of asthma in patients admitted by other diseases, as it may have a relevant impact on clinical and health services outcomes.

Subtypes of Adult-Onset Asthma at the Time of Diagnosis: A Latent Class Analysis

INTRODUCTION

Only a few previous studies have investigated the subtypes of adult-onset asthma. No previous study has assessed whether these subtypes are different between men and women, or whether these subtypes have different risk factors.

METHODS

We applied latent class analyses to the Finnish Environment and Asthma Study population, including 520 new cases of adult-onset asthma. We formed subtypes separately between women and men and analyzed the following determinants as potential predictors for these subtypes: age, body mass index, smoking, and parental asthma.

RESULTS

Among women, the subtypes identified were: 1. Moderate asthma, 2. Cough-variant asthma, 3. Eosinophilic asthma, 4. Allergic asthma, and 5. Difficult asthma. Among men, the subtypes were: 1. Mild asthma, 2. Moderate asthma, 3. Allergic asthma, and 4. Difficult asthma. Three of the subtypes were similar among women and men: Moderate, Allergic, and Difficult asthma. In addition, women had two distinct subtypes: Cough-variant asthma, and Eosinophilic asthma. These subtypes had different risk factor profiles, e.g., heredity was important for Eosinophilic and Allergic asthma (RR for Both parents having asthma in Eosinophilic 3.55 (1.09 to 11.62)). Furthermore, smoking increased the risk of Moderate asthma among women (RR for former smoking 2.21 (1.19 to 4.11)) and Difficult asthma among men but had little influence on Allergic or Cough-variant asthma. Conclusion: This is an original investigation of the subtypes of adult-onset asthma identified at the time of diagnosis. These subtypes differ between women and men, and these subtypes have different risk factor profiles. These findings have both clinical and public health importance for the etiology, prognosis, and treatment of adult-onset asthma.

Upper respiratory tract microbiota is associated with small airway function and asthma severity

BACKGROUND

Characteristics of airway microbiota might influence asthma status or asthma phenotype. Identifying the airway microbiome can help to investigate its role in the development of asthma phenotypes or small airway function.

METHODS

Bacterial microbiota profiles were analyzed in induced sputum from 31 asthma patients and 12 healthy individuals from Beijing, China. Associations between small airway function and airway microbiomes were examined.

RESULTS

Composition of sputum microbiota significantly changed with small airway function in asthma patients. Two microbiome-driven clusters were identified and characterized by small airway function and taxa that had linear relationship with small airway functions were identified.

CONCLUSIONS

Our findings confirm that airway microbiota was associated with small airway function in asthma patients.

Mendelian randomization study shows a causal effect of asthma on epilepsy risk

Objective

The relationship between asthma and epilepsy in observational studies is controversial. The purpose of this Mendelian randomization (MR) study is to investigate whether asthma causally contributes to epilepsy susceptibility.

Methods

Independent genetic variants strongly (P<5E-08) associated with asthma were from a recent meta-analysis of genome-wide association studies on 408,442 participants. Two independent summary statistics of epilepsy obtained from the International League Against Epilepsy Consortium (ILAEC, Ncases=15,212, and Ncontrols=29,677) and FinnGen Consortium (Ncases=6,260 and Ncontrols=176,107) were used in the discovery and replication stage, respectively. Several sensitivity analyses and heterogeneity analyses were further conducted to assess the stability of the estimates.

Results

Using the inverse-variance weighted approach, genetic predisposition to asthma was associated with an elevated risk of epilepsy in the discovery stage (ILAEC: odds ratio [OR]=1.112, 95% confidence intervals [CI]= 1.023-1.209, P = 0.012), but not verified in the replication stage (FinnGen: OR=1.021, 95%CI= 0.896-1.163, P =0.753). However, a further meta-analysis of both ILAEC and FinnGen showed a similar result (OR=1.085, 95% CI: 1.012-1.164, P = 0.022). There were no causal associations between the age onset of asthma and epilepsy. Sensitivity analyses yielded consistent causal estimates.

Conclusion

The present MR study suggests that asthma is associated with an increased risk of epilepsy independent of the age onset of asthma. Further studies are warranted to explain the underlying mechanisms of this association.

Documentation of smoking in scheduled asthma contacts in primary health care: a 12-year follow-up study

Smoking among asthmatics is common and associates with poorer asthma control, more rapid lung function decline and higher health care costs in dose-dependent manner. No previous real-life studies exist, however, on how smoking status and pack-years are documented in scheduled asthma contacts in primary health care (PHC) during long-term follow-up, and how often patients are advised to quit smoking. In this real-life 12-year follow-up study, we showed that out of all scheduled PHC asthma contacts (n = 603) smoking was mentioned only in 17.2% and pack-years only in 6.5%. Smoking data was not recorded even once in 70.9% of never smokers, 64.7% of ex-smokers and 27.3% of current smokers. Smoking including pack-years were mentioned more often if nurse took part on the scheduled contact. For current smokers, smoking cessation was recommended only in 21.7% of their scheduled contacts. Current smokers used more antibiotics and had more unscheduled health care contacts during follow-up.

Risk factors associated with comorbid asthma in patients with chronic rhinosinusitis with nasal polyps: a cross-sectional study

Background

Although 20–60% of patients with chronic rhinosinusitis with nasal polyps (CRSwNP) have asthma, the risk factors associated with comorbid asthma are not clear. The aim of the study was to investigate the factors associated with asthma, and develop a practical scoring system to screen asthma comorbidity in CRSwNP patients.

Methods

This report describes a cross-sectional study with consecutive CRSwNP patients. Two cohorts of CRSwNP patients named “modelling” group and “validation” group were investigated respectively. Logistic regression analysis was performed based on demographic and clinical data collected from patients in the modelling group to determine the risk factors associated with asthma, and establish a scoring system for screening comorbid asthma. Receiver operating characteristic curve was constructed to evaluate the screening system; the optimal cut-off point was established by means of the Yoden Index. The consistency between the diagnosis of asthma by the Global Initiative for Asthma (GINA) criteria and by the screening system was assessed by Kappa value in the validation group.

Results

Totally 150 patients in modelling group and 78 patients in validation group were enrolled. Female gender (odds ratio [OR] = 6.4; P < 0.001), allergic rhinitis (OR = 2.9; P = 0.021), serum total (T)-immunoglobulin (Ig) E ≥ 69.0kU/L (OR = 12.0; P < 0.001), and blood eosinophil count  ≥ 0.35 × 10⁹/L (OR = 4.0; P = 0.001) were shown to be independent risk factors for asthma in patients with CRSwNP. Based on these variables, a scoring system (FAIE) ranging from 0(no risk) to 6(high risk); was developed. The area under the receiver operating characteristic curve of the system was 0.823, and the optimal cut-off value was 3 points, with sensitivity 83.8% and specificity 68.6% for screening asthma. The asthma comorbidity determined with FAIE score ≥ 3 points in the validation group, was moderately consistent with that defined by GINA (Kappa = 0.513, P < 0.001), with sensitivity 76.9% and specificity 74.4%.

Conclusions

Female gender, allergic rhinitis, serum T-IgE level, and blood eosinophil count are independent risk factors for asthma comorbidity in patients with CRSwNP, and the FAIE system may be practical for screening comorbid asthma in these patients.

Comorbidities in childhood-onset and adult-onset asthma

BACKGROUND

Age of asthma onset has emerged as an important determinant of asthma phenotypes; however, the comorbidities that predominate in either childhood- or adult-onset asthma are not known.

OBJECTIVE

To identify comorbidities associated with adult-onset asthma vs childhood-onset asthma and with age of asthma diagnosis.

METHODS

We analyzed data on 27,437 adult participants in the National Health and Nutrition Examination Surveys conducted from 2001 to 2018. Logistic regression adjusted for covariates was used to identify comorbidities associated with the asthma phenotypes and age of asthma diagnosis.

RESULTS

Approximately 12.6% of participants were ever diagnosed with asthma; the prevalence of childhood-onset (before 18 years old) and adult-onset (≥ 18 years old) current asthma was 2.7% and 5.5%, respectively. After adjustment for covariates including age, adult-onset asthma was associated with higher odds of obesity (odds ratio [OR], 1.46; 95% confidence interval [CI], 1.09-1.96), hypercholesterolemia (OR, 1.67; 95% CI, 1.08-2.56), borderline high serum triglycerides (OR, 1.78; 95% CI, 1.17-2.71), and osteoarthritis (OR, 1.52; 95% CI, 1.04-2.20) than was childhood-onset asthma. Older age of asthma diagnosis (per 5-year increase) was also associated with higher odds of diabetes (OR, 1.04; 95% CI, 1.00-1.07) and hypertension (OR, 1.05; 95% CI, 1.02-1.07), whereas younger age of asthma diagnosis was associated with higher odds of chronic obstructive pulmonary disease (OR, 1.12; 95% CI, 1.04-1.19).

CONCLUSION

Age- and covariates-adjusted prevalence of obesity, dyslipidemia, arthritis, diabetes, and hypertension is higher in adult-onset asthma than in childhood-onset asthma, and with older age of asthma diagnosis. Conversely, the prevalence of chronic obstructive pulmonary disease increases with younger age of asthma diagnosis.

Disease Control, Not Severity, Drives Job Absenteeism in Young Adults with Asthma - A Nationwide Cohort Study

Introduction

The impact of asthma and disease control on job absenteeism in young adults is sparsely investigated and conflicting evidence exist. Based on a nationwide cohort, the present study aims to describe the overall job absenteeism across asthma severities and describe the possible influence of asthma control.

Methods

REASSESS is a nationwide cohort of Danish asthma patients aged 18–45 using controller medication between 2014 and 2018, followed retrospectively for up to 15 years using national databases. Impact of asthma was investigated using negative binomial regression adjusted for age, sex, Charlson score and level of education and presented as adjusted incidence rate ratios with 95% confidence intervals.

Results

A total of 60,534 patients with asthma (median age 33 (25, 39), 55% female, 19% uncontrolled disease and 5.7% possible severe asthma) were followed for 12.7 (6.5–14.8) years. The prevalence of any absenteeism was more common in both mild-to-moderate and possible severe asthma compared to the background population (67%, 80% and 62%, respectively; p < 0.0001). Compared to the background population, mild-to-moderate and possible severe asthma were more likely to have temporary sick leave (1.37 (1.33–1.42); 1.78 (1.62–1.96)), unemployment (1.11 (1.07–1.14); 1.26 (1.15–1.38)) and obtain disability benefits (1.67 (1.66–1.67); 2.64 (2.63–2.65)). Uncontrolled asthma had increased temporary sick leave (1.42 (1.34–1.50)), unemployment (1.40 (1.32–1.48)) and disability (1.26 (1.26–1.27)) when compared to controlled disease. Significant increases in absenteeism could be measured already at ≥100 annual doses of rescue medication (1.09 (1.04–0.1.14)), patients’ first moderate or severe exacerbation (1.31 (1.15–1.49) and 1.31 (1.24–1.39), respectively). Further increases in absenteeism were observed with increasing rescue medication use and severe exacerbations.

Conclusion

Across severities, job absenteeism is increased among patients with asthma compared to the background population. Increases in absenteeism was seen already at ≥100 annual doses of rescue medication, representing a substantial, and probably preventable, reduction in productivity among young adults.

Relationship Between Soluble Urokinase Plasminogen Activator Receptor (suPAR) and Disease Outcome in Adult-Onset Asthma

Background

Objective

Methods

Results

Conclusion

Genome-Wide Interaction Study of Late-Onset Asthma With Seven Environmental Factors Using a Structured Linear Mixed Model in Europeans

Asthma is among the most common chronic diseases worldwide, creating a substantial healthcare burden. In late-onset asthma, there are wide global differences in asthma prevalence and low genetic heritability. It has been suggested as evidence for genetic susceptibility to asthma triggered by exposure to multiple environmental factors. Very few genome-wide interaction studies have identified gene-environment (G×E) interaction loci for asthma in adults. We evaluated genetic loci for late-onset asthma showing G×E interactions with multiple environmental factors, including alcohol intake, body mass index, insomnia, physical activity, mental status, sedentary behavior, and socioeconomic status. In gene-by-single environment interactions, we found no genome-wide significant single-nucleotide polymorphisms. However, in the gene-by-multi-environment interaction study, we identified three novel and genome-wide significant single-nucleotide polymorphisms: rs117996675, rs345749, and rs17704680. Bayes factor analysis suggested that for rs117996675 and rs17704680, body mass index is the most relevant environmental factor; for rs345749, insomnia and alcohol intake frequency are the most relevant factors in the G×E interactions of late-onset asthma. Functional annotations implicate the role of these three novel loci in regulating the immune system. In addition, the annotation for rs117996675 supports the body mass index as the most relevant environmental factor, as evidenced by the Bayes factor value. Our findings help to understand the role of the immune system in asthma and the role of environmental factors in late-onset asthma through G×E interactions. Ultimately, the enhanced understanding of asthma would contribute to better precision treatment depending on personal genetic and environmental information.

Observations of Delayed Changes in Respiratory Function among Allergy Clinic Patients Exposed to Wildfire Smoke

Wildfires have increased in frequency and magnitude and pose a significant public health challenge. The principal objective of this study was to assess the impact of wildfire smoke on respiratory peak flow performance of patients exposed to two different wildfire events. This longitudinal study utilized an observational approach and a cohort study design with a patient-level clinical dataset from a local outpatient allergy clinic (n = 842). Meteorological data from a local weather station served as a proxy for smoke exposure because air quality measurements were not available. This study found that there were decreases in respiratory peak flow among allergy clinic patients one year after each wildfire event. For every one percent increase in wind blowing from the fire towards the community, there was, on average, a 2.21 L per minute decrease in respiratory peak flow. This study observed an effect on respiratory peak flow performance among patients at a local allergy clinic one year after suspected exposure to wildfire smoke. There are likely multiple reasons for the observation of this relationship, including the possibility that wildfire smoke may enhance allergic sensitization to other allergens or that wildfire smoke itself may elicit a delayed immune response.

Clinical value of bronchodilator response for diagnosing asthma in steroid-naïve adults

Spirometry and testing for bronchodilator response have been recommended to detect asthma, and a bronchodilator response (BDR) of ≥12% and ≥200 mL has been suggested to confirm asthma. However, the clinical value of bronchodilation tests in newly diagnosed steroid-naïve adult patients with asthma remains unknown. We evaluated the sensitivity of BDR in forced expiratory volume in 1 s (FEV₁) as a diagnostic test for asthma in a real-life cohort of participants in the Seinäjoki Adult Asthma Study. In the diagnostic phase, 369 spirometry tests with bronchodilation were performed for 219 steroid-naïve patients. The fulfilment of each test threshold was assessed. According to the algorithm of the National Institute for Health and Care Excellence, we divided the patients into obstructive (FEV₁/forced vital capacity (FVC) <0.70) and non-obstructive (FEV₁/FVC ≥0.70) groups. Of the overall cohort, 35.6% fulfilled ΔFEV₁ ≥12% and ≥200 mL for the initial FEV₁, 18.3% fulfilled ΔFEV₁ ≥15% and ≥400 mL for the initial FEV₁, and 36.1% fulfilled ΔFEV₁ ≥9% of predicted FEV₁ at least once. One-third (31%) of these steroid-naïve patients was obstructive (pre-bronchodilator FEV₁/FVC <0.7). Of the obstructive patients, 55.9%, 26.5% and 48.5%, respectively, met the same thresholds. In multivariate logistic regression analysis, different thresholds recognised different kinds of asthma patients. In steroid-naïve adult patients, the current BDR threshold (ΔFEV₁ ≥12% and ≥200 mL) has low diagnostic sensitivity (36%) for asthma. In obstructive patients, sensitivity is somewhat higher (56%) but far from optimal. If the first spirometry test with bronchodilation is not diagnostic but asthma is suspected, spirometry should be repeated, and other lung function tests should be used to confirm the diagnosis.

Influence of Childhood Exposure to a Farming Environment on Age at Asthma Diagnosis in a Population-Based Study

Purpose

Asthma is a heterogeneous disease, and factors associated with different asthma phenotypes are poorly understood. Given the higher prevalence of farming exposure and late diagnosis of asthma in more rural Western Finland as compared with the capital of Helsinki, we investigated the relationship between childhood farming environment and age at asthma diagnosis.

Methods

A cross-sectional population-based study was carried out with subjects aged 20–69 years in Western Finland. The response rate was 52.5%. We included 3864 participants, 416 of whom had physician-diagnosed asthma at a known age and with data on the childhood environment. The main finding was confirmed in a similar sample from Helsinki. Participants were classified as follows with respect to asthma diagnosis: early diagnosis (0–11 years), intermediate diagnosis (12–39 years), and late diagnosis (40–69 years).

Results

The prevalence of asthma was similar both without and with childhood exposure to a farming environment (11.7% vs 11.3%). Allergic rhinitis, family history of asthma, ex-smoker, occupational exposure, and BMI ≥ 30 kg/m² were associated with a higher likelihood of asthma. Childhood exposure to a farming environment did not increase the odds of having asthma (aOR, 1.10; 95% CI, 0.87–1.40). It did increase the odds of late diagnosis (aOR, 2.30; 95% CI, 1.12–4.69), but the odds were lower for early (aOR, 0.49; 95% CI, 0.30–0.80) and intermediate diagnosis of asthma (aOR, 0.75; 95% CI, 0.47–1.18).

Conclusion

Odds were lower for early diagnosis of asthma and higher for late diagnosis of asthma in a childhood farming environment. This suggests a new hypothesis concerning the etiology of asthma when it is diagnosed late.

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Asthma Phenotypes as a Guide for Current and Future Biologic Therapies

Asthma has been increasingly recognized as being a heterogeneous disease with multiple distinct mechanisms and pathophysiologies. Evidence continues to build regarding the existence of different cell types, environmental exposures, pathogens, and other factors that produce a similar set of symptoms known collectively as asthma. This has led to a movement from a "one size fits all" symptom-based methodology to a more patient-centered, individualized approach to asthma treatment targeting the underlying disease process. A significant contributor to this shift to more personalized asthma therapy has been the increasing availability of numerous biologic therapies in recent years, providing the opportunity for more targeted treatments. When targeted biologics began to be developed for treatment of asthma, the hope was that distinct biomarkers would become available, allowing the clinician to determine which biologic therapy was best suited for which patients. Presence of certain biomarkers, like eosinophilia or antigen-specific IgE, is important features of specific asthma phenotypes. Currently available biomarkers can help with decision making about biologics, but are generally too broad and non-specific to clearly identify an asthma phenotype or the single biologic best suited to an asthmatic. Identification of further biomarkers is the subject of intense research. Yet, identifying a patient's asthma phenotype can help in predicting disease course, response to treatment, and biologic therapies to consider. In this review, major asthma phenotypes are reviewed, and the evidence for the utility of various biologics, both those currently on the market and those in the development process, in each of these phenotypes is explored.

Long-term prognosis of new adult-onset asthma in obese patients

Background

Obesity has been associated with poor outcomes of asthma in cross-sectional studies, but long-term effect of obesity on asthma remains unknown.

Aims

To study the effects of obesity, found at the time of diagnosis of adult-onset asthma, on 12-year prognosis by focusing on oral corticosteroid (OCS) use and respiratory-related hospital admissions.

Methods

Patients diagnosed with adult-onset asthma (n=203) were divided into three categories based on diagnostic body mass index (BMI) (<25 kg·m⁻², 25–29.9 kg·m⁻², ≥30 kg·m⁻²) and followed for 12 years as part of the Seinäjoki Adult Asthma Study. Self-reported and dispensed OCS were assessed for the 12-year period. Data on hospital admissions were analysed based on medical records.

Results

12 years after diagnosis, 86% of the patients who were obese (BMI ≥30 kg·m⁻²) at diagnosis remained obese. During the follow-up, no difference was found in weight gain between the BMI categories. During the 12-year follow-up, patients obese at diagnosis reported more frequent use of OCS courses (46.9% versus 23.1%, p=0.028), were dispensed OCS more often (81.6% versus 56.9%, p=0.014) and at higher doses (median 1350 (interquartile range 280–3180) mg versus 600 (0–1650) mg prednisolone, p=0.010) compared to normal-weight patients. Furthermore, patients who were obese had more often one or more respiratory-related hospitalisations compared to normal-weight patients (38.8% versus 16.9%, p=0.033). In multivariate logistic regression analyses, obesity predicted OCS use and hospital admissions.

Conclusions

In adult-onset asthma, patients obese at diagnosis mostly remained obese at long-term and had more exacerbations and respiratory-related hospital admissions compared to normal-weight patients during 12-year follow-up. Weight loss should be a priority in their treatment to prevent this outcome.

Obese patients with new adult-onset asthma often remain obese in the long-term and have more exacerbations and respiratory-related hospital admissions during follow-up. High priority should be given to weight loss during treatment to prevent this outcome.https://bit.ly/2G5HtRZ

Level of education and asthma control in adult-onset asthma

OBJECTIVE

Education in itself and as a proxy for socioeconomic status, may influence asthma control, but remains poorly studied in adult-onset asthma. Our aim was to study the association between the level of education and asthma control in adult-onset asthma.

METHODS

Subjects with current asthma with onset >15 years were examined within the Obstructive Lung Disease in Northern Sweden study (OLIN, n = 593), Seinäjoki Adult Asthma Study (SAAS, n = 200), and West Sweden Asthma Study (WSAS, n = 301) in 2009-2014 in a cross-sectional setting. Educational level was classified as primary, secondary and tertiary. Uncontrolled asthma was defined as Asthma Control Test (ACT) score ≤19. Altogether, 896 subjects with complete data on ACT and education were included (OLIN n = 511, SAAS n = 200 and WSAS n = 185).

RESULTS

In each cohort and in pooled data of all cohorts, median ACT score was lower among those with primary education than in those with secondary and tertiary education. Uncontrolled asthma was most common among those with primary education, especially among daily ICS users (42.6% primary, 28.6% secondary and 24.2% tertiary; p = 0.001). In adjusted analysis, primary education was associated with uncontrolled asthma in daily ICS users (OR 1.92, 95% CI 1.15-3.20). When stratified by atopy, the association between primary education and uncontrolled asthma was seen in non-atopic (OR 3.42, 95% CI 1.30-8.96) but not in atopic subjects.

CONCLUSIONS

In high-income Nordic countries, lower educational level was a risk factor for uncontrolled asthma in subjects with adult-onset asthma. Educational level should be considered in the management of adult-onset asthma.

Adults with current asthma but not former asthma have higher all-cause and cardiovascular mortality: a population-based prospective cohort study

Higher mortality in asthmatics has been shown previously. However, evidence on different asthma phenotypes on long-term mortality risk is limited. The aim was to evaluate the impact of asthma phenotypes on mortality in general population. Data from the National Health and Nutrition Examination Survey from 2001–2002 to 2013–2014 linked mortality files through December 31, 2015, were used (N = 37,015). Cox proportional hazards regression was used to estimate the risk of all-cause and cause-specific mortality adjusting for sociodemographic characteristics, smoking, body mass index, and chronic conditions. During the mean follow-up time of 7.5 years, 4326 participants died from a variety of causes. Current asthma, but not former asthma was associated with increased all-cause mortality (current asthma: HR = 1.37; 95% CI 1.20–1.58; Former asthma: HR = 0.93; 95% CI 0.73–1.18); as well as mortality from cardiovascular disease (HR_Current = 1.41; 95% CI 1.08–1.85) and chronic lower respiratory diseases (HR_Current = 3.17; 95% CI 1.96–5.14). In addition, we found that the HR for cardiovascular disease (CVD) mortality was slightly greater in people with childhood-onset asthma than those with adult-onset asthma. The HR for chronic lower respiratory diseases (CLRD) mortality was greater in people with adult-onset asthma than those with childhood-onset asthma. However, the differences were not statistically significant. Our study suggested that current asthma but not former asthma was associated with increased all-cause, CLRD and CVD mortality. Future well-designed studies with larger sample are required to demonstrate the association and clarify the potential mechanisms involved.

Long-term adherence to inhaled corticosteroids and asthma control in adult-onset asthma

BACKGROUND

In short-term studies, poor adherence to inhaled corticosteroids (ICS) has been associated with worse asthma control, but the association of long-term adherence and disease control remains unclear.

OBJECTIVE

To assess the relationship between 12-year adherence to ICS and asthma control in patients with adult-onset asthma.

METHODS

As part of the Seinäjoki Adult Asthma Study, 181 patients with clinically confirmed new-onset adult asthma and regular ICS medication were followed-up for 12 years. Adherence (%) to ICS was assessed individually ((µg dispensed/µg prescribed)×100) during the follow-up. Asthma control was evaluated after 12 years of treatment according to the Global Initiative for Asthma 2010 guideline.

RESULTS

Asthma was controlled in 31% and not controlled (partly controlled or uncontrolled) in 69% of the patients. Patients with not-controlled asthma were more often male, older, nonatopic and used higher doses of ICS than those with controlled disease. The mean±sd 12-year adherence to ICS was 63±38% in patients with controlled asthma and 76±40% in patients with not-controlled disease (p=0.042). Among patients with not-controlled asthma, those with lower 12-year adherence (<80%) had more rapid decline in forced expiratory volume in 1 s (-47 mL·year-1) compared to patients with better adherence (≥80%) (-40 mL·year-1) (p=0.024). In contrast, this relationship was not seen in patients with controlled asthma.

CONCLUSIONS

In adult-onset asthma, patients with not-controlled disease showed better 12-year adherence to ICS treatment than those with controlled asthma. In not-controlled disease, adherence <80% was associated with more rapid lung function decline, underscoring the importance of early recognition of such patients in routine clinical practice.

Revisiting Late-Onset Asthma: Clinical Characteristics and Association with Allergy

The Global Initiative for Asthma (GINA) 2020 defines late-onset asthma (LOA) as one of the clinical phenotypes of asthma wherein patients, particularly women, present with asthma for the first time in adult life, tend to be non-allergic and often require higher doses of inhaled corticosteroids (ICS) or are relatively refractory to corticosteroid treatment. In this review, we examine the published literature improve the understanding of the following aspects of LOA: 1) the age cut-off for its diagnosis; 2) its distinct clinical phenotypes, characteristics and risk factors; and 3) its association with allergic comorbidities and conditions. Overall, our review reveals that clinicians and researchers have used multiple age cut-offs to define LOA, with cut-off ages ranging from >12 years to ≥65 years. LOA has also been classified into several distinct phenotypes, some of which drastically differ in their clinical characteristics, course and prognosis. Although LOA has traditionally been considered non-allergic in nature, our review indicates that it is commonly associated with allergic features and comorbidities. Our findings suggest that there is an urgent need for the development of more clear clinical practice guidelines that can provide more clarity on the definition and other aspects of LOA. In addition, the association of LOA and allergy needs to be re-examined to frame a more optimal treatment strategy for patients with LOA.

Pharmacotherapeutic management of asthma in the elderly patient

INTRODUCTION

Asthma is a heterogeneous syndrome with variable phenotypes. Reversible airway obstruction and airway hyper-responsiveness often with an atopic or eosinophilic component is common in the elderly asthmatic. Asthma chronic obstructive pulmonary disease overlap syndrome (ACOS), a combination of atopy-mediated airway hyper-responsiveness and a history of smoking or other environmental noxious exposures, can lead to some fixed airway obstruction and is also common in elderly patients. Little specific data exist for the treating the elderly asthmatic, thus requiring the clinician to extrapolate from general adult data and asthma treatment guidelines.

AREAS COVERED

A stepwise approach to pharmacotherapy of the elderly patient with asthma and ACOS is offered and the literature supporting the use of each class of drugs reviewed.

EXPERT OPINION

Inhaled, long-acting bronchodilators in combination with inhaled corticosteroids represent the backbone of treatment for the elderly patient with asthma or ACOS . Beyond these medications used as direct bronchodilators and topical anti-inflammatory agents, a stepwise approach to escalation of therapy includes multiple options such as oral leukotriene receptor antagonist or 5-lipoxygense inhibitor therapy, oral phosphodiesterase inhibitors, systemic corticosteroids, oral macrolide antibiotics and if evidence of eosinophilic/atopic component disease exists then modifying monoclonal antibody therapies.

Development of self-assessed work ability among middle-aged asthma patients-a 10 year follow-up study

OBJECTIVE

The prevalence of asthma has been growing among working age people over the last decades. In this study, we examine the development of Work Ability Score (WAS) among middle-aged asthmatics in a longitudinal setting, in order to find risk factors for poor development.

METHODS

We followed the development of WAS trends during 10 years in a cohort of 529 middle-aged asthmatics, who were active in working life. Follow-up questionnaires were mailed in years 1, 2, 4, 6, 8, and 10. To study the development of WAS over time, we computed the discrete Frechet distance, which describes the similarity between the shapes of WAS curves.

RESULTS

Sixty-eight percent of the patients' WAS remained good or excellent throughout the follow-up period, while 24% of the patients WAS trend remained moderate. However, in 8%, the WAS was poor already in baseline and decreased further throughout the study. Using logistic regression, the moderate/poor development was associated significantly with high body mass index (BMI), pack years, adult onset asthma, physically strenuous work, number of co-morbidities, especially in psychiatric conditions, hypertension, and gastroesophageal reflux disease(GERD). When the model was adjusted for age and gender, adulthood onset of asthma and pack years lost their significance. Based on medication (high dose of inhaled corticosteroids (ICS) and second controller in use), 8% of the patients had severe asthma.

CONCLUSION

In the great majority of middle-aged asthma patients WAS remained stable throughout the follow-up period. However, 8% of the patients, who had more severe asthma and multiple co-morbidities, showed significantly poorer outcomes.

Airway Epithelial Dynamics in Allergy and Related Chronic Inflammatory Airway Diseases

Allergic rhinitis, chronic rhinosinusitis, and asthma are highly prevalent, multifactorial chronic airway diseases. Several environmental and genetic factors affect airway epithelial dynamics leading to activation of inflammatory mechanisms in the airways. This review links environmental factors to host epithelial immunity in airway diseases. Understanding altered homeostasis of the airway epithelium might provide important targets for diagnostics and therapy of chronic airway diseases.

12-year adherence to inhaled corticosteroids in adult-onset asthma

Adherence to inhaled corticosteroids (ICS) has been suggested to be poor but long-term follow-ups are lacking. The objective of the present study was to assess adherence to ICS treatment in patients with adult-onset asthma during 12-year follow-up.

A total of 181 patients with clinically confirmed, new-onset adult asthma were followed for 12 years as part of the Seinäjoki Adult Asthma Study. Adherence to ICS was assessed individually as the percentage of true dispensed ICS in micrograms per true prescribed daily ICS in micrograms over 12 years.

Mean 12-year adherence to ICS was 69% (mean±sd dispensed 2.5±1.8 g and prescribed 3.6±1.5 g budesonide equivalent per patient for 12 years), annual adherence varying between 81% (year 1) and 67% (year 12). Patients with good 12-year adherence (≥80%) used oral corticosteroids more often, and had add-on drugs in use and asthma-related visits to healthcare more often. In addition, they showed less reversibility in forced expiratory volume in 1 s and had higher peripheral blood neutrophil counts. However, lung function decline was steeper in patients with poorer adherence (<80%) and this association remained in multiple linear regression analysis. No difference was found in symptom scores, blood eosinophil counts, exhaled nitric oxide or immunoglobulin E between the patients with different levels of adherence.

In patients with adult-onset asthma, adherence to ICS was moderate. Poorer adherence (<80%) to ICS was associated with more rapid decline in lung function but was not associated to symptoms or markers of inflammatory endotypes.

Mean long-term adherence to ICS treatment is 69% in patients with confirmed adult-onset asthma. While good ICS adherence (≥80%) is associated with features of more severe asthma, poorer adherence (<80%) predicts more rapid lung function decline.http://bit.ly/37mvh74

Immunologic and Non-Immunologic Mechanisms Leading to Airway Remodeling in Asthma

Asthma increases worldwide without any definite reason and patient numbers double every 10 years. Drugs used for asthma therapy relax the muscles and reduce inflammation, but none of them inhibited airway wall remodeling in clinical studies. Airway wall remodeling can either be induced through pro-inflammatory cytokines released by immune cells, or direct binding of IgE to smooth muscle cells, or non-immunological stimuli. Increasing evidence suggests that airway wall remodeling is initiated early in life by epigenetic events that lead to cell type specific pathologies, and modulate the interaction between epithelial and sub-epithelial cells. Animal models are only available for remodeling in allergic asthma, but none for non-allergic asthma. In human asthma, the mechanisms leading to airway wall remodeling are not well understood. In order to improve the understanding of this asthma pathology, the definition of “remodeling” needs to be better specified as it summarizes a wide range of tissue structural changes. Second, it needs to be assessed if specific remodeling patterns occur in specific asthma pheno- or endo-types. Third, the interaction of the immune cells with tissue forming cells needs to be assessed in both directions; e.g., do immune cells always stimulate tissue cells or are inflamed tissue cells calling immune cells to the rescue? This review aims to provide an overview on immunologic and non-immunologic mechanisms controlling airway wall remodeling in asthma.

Metabolic Syndrome and Incident Asthma in Chinese Adults: An Open Cohort Study

BACKGROUND

Although metabolic syndrome is awell-known risk factor for many non-communicable diseases, its contribution to asthma remains controversial.

OBJECTIVE

The aim of this study was to explore the associations of metabolic syndrome and its components with incident asthma in Chinese adults.

METHODS

We conducted an open cohort study of participants who were asthma-free at baseline (n=42,304) in the Shandong multi-center health check-up longitudinal study from 2004 to 2015. Participants aged ≥20 years and had regular physical examination (once ayear) more than three times during follow-up.

RESULTS

Ninety subjects (38 women and 52 men) developed incident asthma over 12 years of follow-up. Our study suggested that metabolic syndrome itself was not significantly associated with incident asthma in either women or men (P>0.050). Interestingly, we found that overweight and/or obesity was arisk factor for incident asthma among women but not men in the Cox proportional hazards model after adjusting covariates (adjusted incidence rate ratio (IRR)= 2.940, 95% confidence interval (CI): 1.467-5.894, P=0.002). The result was consistent with the Poisson regression model (hazard ratio (HR)= 2.241, 95% CI: 1.135-4.988, P=0.026). After stratifying according to overweight and/or obesity, we found that female subjects with overweight and obesity were associated with the occurrence of incident asthma (P<0.050). However, we did not find this result among men.

CONCLUSION

Metabolic syndrome was not significantly associated with incident asthma in both women and men; however, overweight and/or obesity was shown to be asignificant risk factor for incident asthma but only in women, not in men.

Effect of asthma control on general health-related quality of life in patients diagnosed with adult-onset asthma

Health-related quality of life (HRQoL) is a well-established aspect of health that can be measured by both disease-specific and general instruments. The effect of uncontrolled asthma on generic HRQoL has not been shown in patients with clinically confirmed adult-onset asthma and with asthma control defined according to the Global Initiative for Asthma, so the aim of this study was to determine this. In the 12-year follow-up cohort of the Seinäjoki Adult Asthma Study (n = 203), patients with uncontrolled and partially controlled asthma had lower generic HRQoL as determined by 15D compared to the controlled group. On 10 out of 15 dimensions of 15D, the mean scores were significantly lower in patients with uncontrolled asthma compared with those with controlled asthma. The affected dimensions were mobility, breathing, sleeping, usual activities, mental function, discomfort and symptoms, depression, distress, vitality and sexual activity. In the Tobit regression analysis, a poorer 15D score was associated with uncontrolled asthma, lower postbronchodilator FEV₁, female sex, depression, treated dyspepsia and poorer 15D score at diagnosis. Our results show that uncontrolled asthma affects everyday life in several aspects, including previously unknown components such as sexual activity and vitality.

Innate Lymphoid Cell-Dependent Airway Epithelial and Inflammatory Responses to Inhaled Ozone: A New Paradigm in Pathogenesis

Epidemiological associations have been made between the new onset of childhood rhinitis/asthma and exposures to elevated ambient levels of ozone, a commonly encountered gaseous air pollutant. Our laboratory was the first to find that mice repeatedly exposed to ozone develop nasal type 2 immunity and eosinophilic rhinitis with mucous cell metaplasia. More recently, we have found that these ozone-induced upper airway alterations are mediated by group 2 innate lymphoid cells (ILC2s) and not by T and B cells that are important in adaptive immune responses typically associated with allergic rhinitis and asthma. Furthermore, repeated exposures of mice to ozone cause ILC2-mediated type 2 immunity and airway pathology in the lungs, like those found in the nasal airways. Our recent findings in ozone-exposed mice complement and extend previous reports of nonallergic nasal airway disease in ozone-exposed rats and nonhuman primates. Overall, these experimental results in laboratory animals suggest a plausible ILC2-dependent paradigm for the toxicologic pathobiology that underlies the development of nonallergic rhinitis/asthma in children who live in environments with repeated occurrences of high ambient concentrations of ozone.

Distinct asthma phenotypes with low maximal attainment of lung function on cluster analysis

OBJECTIVE

Asthma is a heterogeneous disease with varying clinical presentations, severity and ability to achieve asthma control. The present study aimed to characterize clinical phenotypes of asthma in an Indian cohort of subjects using a cluster analysis approach.

METHODS

Patients with confirmed asthma (N = 100) and at least 6-months of follow-up data, identified by retrospective chart review, were included in this study. Demographics, age at disease onset, disease duration, body mass index, serial spirometry and allergen sensitization were assessed. Asthma control was assessed prospectively using Global Initiative for Asthma and Asthma Control Test. R version 3.4.3 was used for statistical analysis. Ward's minimum-variance hierarchical clustering method was performed using an agglomerative (bottom-up) approach. To compare differences between clusters, analysis of variance using Kruskal-Wallis test (continuous variables) and chi-square test (categorical variables) was used.

RESULTS

Cluster analysis of 100 treatment-naive patients with asthma identified four clusters. Cluster 1, (N = 40), childhood onset of disease, normal body weight, equal gender distribution and achieved normal lung function. Cluster 2 (N = 16) included adolescent disease-onset, obese, majority males and had poor attainment of maximum lung functions. Cluster 3 (N = 20) were older, late-onset of disease, obese, majority male and had poor attainment of maximum lung function. Cluster 4 (N = 24) had adult-onset of disease, obese, predominantly female and achieved normal lung function.

CONCLUSIONS

In an Indian cohort of well-characterized patients with asthma, cluster analysis identified four distinct clinical phenotypes of asthma, two of which had poor attainment of maximum lung functions.

The increase of asthma prevalence has levelled off and symptoms decreased in adults during 20 years from 1996 to 2016 in Helsinki, Finland

BACKGROUND

Mortality and hospitalization due to asthma have decreased in many European countries, but asthma symptoms still cause a lot of morbidity and costs.

OBJECTIVES

We evaluated prevalence trends of asthma, asthma symptoms and allergic rhinoconjunctivitis in adults aged 20-69 years during a 20-year period from 1996 to 2016 in the city of Helsinki, the capital of Finland.

METHODS

Three cross-sectional postal surveys were conducted in random population samples 10 years apart. In 1996, 2006 and 2016, a total of 6062 (response rate 75.9%), 2449 (61.9%) and 4026 subjects (50.3%) took part, respectively.

RESULTS

In all responders, the prevalence of physician-diagnosed asthma was 6.6% in 1996, 10% in 2006 and 10.9% in 2016. The prevalence increased from 1996 to 2006, but stabilized from 2006 to 2016, both in men and women and in smokers and non-smokers. The prevalence of current asthma (8.5% in 2006 and 8.8% in 2016) and of asthma with rhinoconjunctivitis (7.6% in 2006 and 7.5% in 2016) remained also at the same level. Allergic rhinoconjunctivitis decreased significantly from 2006 (42.7%) to 2016 (39.0%, p = 0.004). Those with physician diagnosed asthma reported significantly less symptoms in 2016 compared to 2006 and 1996, although there was no change in smoking habits or medication use. Young asthmatics (20-29 years) without rhinoconjunctivitis reported least symptoms.

CONCLUSION

Previously observed increase of physician-diagnosed asthma prevalence in adults seems to be levelling off in Helsinki, and patients have fewer symptoms than 20 years ago. In addition, allergic rhinoconjunctivitis is less frequent than 10 years earlier. (247 words).

Immunological Factors Associated with Adult Asthma in the Aseer Region, Southwestern Saudi Arabia

Background: The prevalence of asthma is on the rise in Saudi Arabia. Data regarding the immunological profile of asthma in adults in the Aseer region, in southwestern Saudi Arabia, have not been well studied. Objectives: Our aim was to study the immunological factors associated with sensitization to asthma among adults in the Aseer region. Methods: A cross-sectional study with a nested case control design in a 1:1 ratio was conducted on a sample of adults attending primary health care centers in the Aseer region. The study used a validated Arabic version of the International study of asthma and allergies in childhood (ISAAC) questionnaire. The presence of wheezing in the past 12 months was used as a proxy for bronchial asthma. Matched age and sex controls were selected. Both groups were tested for complete blood count (CBC), total and differential white blood cell (WBC) count including eosinophils, total immunoglobulin E (IgE) measurement, allergen-specific immunoglobulin E (IgE), and cytokine levels. Results: The present study included 110 cases and 157 age- and sex-matched controls. Rye wheat was found to be a significant outdoor sensitizing agent ((odds ratio) OR = 5.23, 95% CI: 1.06–25.69). Indoors, house dust mites Dermatophagoides petronyssinus (OR = 2.04, 95% CI: 1.04–3.99) and Dermatophagoides farinae (OR = 2.50, 95% CI: 1.09–5.75) were significant. Higher total IgE (OR = 1.84, 95% CI: 1.10–3.06) and eosinophil levels (OR = 2.85, 95% CI: 1.14–7.15) were significantly associated with adult bronchial asthma in Aseer. On the other hand, the role of cytokines was not significant. Conclusions: In the present study, certain environmental agents were found to be important with regards to sensitization to bronchial asthma in adults. Knowledge about these sensitization agents should be disseminated to health providers and treating physicians in order to enhance preventive environmental control measures and asthma management. Asthma-treating physicians in the region should be alerted to the use of targeted biological therapies in selected asthmatics with difficult-to-control courses.