The role of female sex hormones in the development and severity of allergic and non-allergic asthma

Impact of sex on severe asthma: a cross-sectional retrospective analysis of UK primary and specialist care

INTRODUCTION

After puberty, females are more likely to develop asthma and in a more severe form than males. The associations between asthma and sex are complex with multiple intrinsic and external factors.

AIM

To evaluate the sex differences in the characteristics and treatment of patients with severe asthma (SA) in a real-world setting.

METHODS

Demographic, clinical and treatment characteristics for patients with SA in the UK Severe Asthma Registry (UKSAR) and Optimum Patient Care Research Database (OPCRD) were retrospectively analysed by sex using univariable and multivariable logistic regression analyses adjusted for year, age and hospital/practice.

RESULTS

3679 (60.9% female) patients from UKSAR and 18 369 patients (67.9% female) from OPCRD with SA were included. Females were more likely to be symptomatic with increased Asthma Control Questionnaire-6 (UKSAR adjusted OR (aOR) 1.14, 95% CI 1.09 to 1.18) and Royal College of Physicians-3 Question scores (OPCRD aOR 1.29, 95% CI 1.13 to 1.47). However, they had a higher forced expiratory volume in 1 second per cent (FEV1%) predicted (UKSAR 68.7% vs 64.8%, p<0.001) with no significant difference in peak expiratory flow. Type 2 biomarkers IgE (UKSAR 129 IU/mL vs 208 IU/mL, p<0.001) and FeNO (UKSAR 36ppb vs 46ppb, p<0.001) were lower in females with no significant difference in blood eosinophils or biological therapy. Females were less likely to be on maintenance oral corticosteroids (UKSAR aOR 0.86, 95% CI 0.75 to 0.99) but more likely to be obese (UKSAR aOR 1.67, 95% CI 145 to 1.93; OPCRD SA aOR 1.46, 95% CI 1.34 to 1.58).

CONCLUSIONS

Females had increased symptoms and were more likely to be obese despite higher FEV1% predicted and lower type 2 biomarkers with consistent and clinically important differences across both datasets.

Determinants associated with uncontrolled asthma in Portugal: A national population-based study

INTRODUCTION AND OBJECTIVES

Asthma is a chronic and heterogeneous disease that affects people of all ages and has a high estimated increase in prevalence worldwide. Asthma control represents a main goal in the disease management. International studies revealed low levels of disease control resulting in a significant burden for healthcare systems, not only in terms of quality of life, but also in terms of health costs. Modifiable and non-modifiable factors have been identified as relating to poor asthma control level. In this study we evaluated the distribution of asthma control levels in Portuguese adult population and examine the determinants associated with uncontrolled asthma.

MATERIALS AND METHODS

Using a similar methodology to the one employed in the Asthma Insights and Reality in Europe (AIRE) survey, 327 active asthmatic patients were identified by random phone number and completed a questionnaire during 2011 to 2012. Asthma control was assessed by the evaluation of GINA based symptom control, by Asthma Control Test.äó (ACT) and by self-perception of control. To examine the relationship between uncontrolled asthma and its determinants, univariate logistic regression analysis, sequential multivariable regression and population attributable risk percentage were determinate.

RESULTS

35.2% active asthmatic patients had uncontrolled asthma, 64.8% partially controlled and none of the individuals had total control of asthma assessed by ACT test. Factors significantly associated with poor asthma control scores were: age (OR 1.02 per year of age; 95% CI: 1.01.Çô1.03), female sex (OR 1.87; 95% CI: 1.15.Çô3.04), educational level (OR 0.5; 95% CI: 0.28.Çô0.89 at high school level or over), occupation (OR 4.92; 95% CI: 2.12.Çô11.42 if looking for a first job or unemployed) (OR 2.51; 95% CI: 1.35.Çô4.65 if being retired), income (OR 0.23; 95% CI: 0.07.Çô0.72 if >619 euros), BMI (OR 1.09 per BMI unit; 95% CI: 1.03.Çô1.14), having rhinitis symptoms (OR 4.40; 95% CI: 2.56.Çô7.58) and using inhaled corticosteroids (OR 0.44; 95%CI: 0.24.Çô0.82 if used in the past or never used). Looking for a first job or being unemployed, BMI and having rhinitis symptoms remained significant after multivariate adjustments.

CONCLUSIONS

Uncontrolled asthma was associated with several determinants. Their identification can contribute to improve asthma care both from clinical and from public health perspectives.

Time-Specific Factors Influencing the Development of Asthma in Children

Susceptibility to asthma is complex and heterogeneous, as it involves both genetic and environmental insults (pre- and post-birth) acting in a critical window of development in early life. According to the Developmental Origins of Health and Disease, several factors, both harmful and protective, such as nutrition, diseases, drugs, microbiome, and stressors, interact with genotypic variation to change the capacity of the organism to successfully adapt and grow in later life. In this review, we aim to provide the latest evidence about predictive risk and protective factors for developing asthma in different stages of life, from the fetal period to adolescence, in order to develop strategic preventive and therapeutic interventions to predict and improve health later in life. Our study shows that for some risk factors, such as exposure to cigarette smoke, environmental pollutants, and family history of asthma, the evidence in favor of a strong association of those factors with the development of asthma is solid and widely shared. Similarly, the clear benefits of some protective factors were shown, providing new insights into primary prevention. On the contrary, further longitudinal studies are required, as some points in the literature remain controversial and a source of debate.

Population-based study of the association between asthma and exogenous female sex hormone use

OBJECTIVES

Several studies have suggested the influence of exogenous hormones on asthma, but the results are still conflicting. Moreover, there has been little associated research on Asian population. This study aimed to assess the association between use of exogenous female sex hormones and asthma in Korean women.

DESIGN

Korea National Health and Nutrition Examination Survey (KNHANES) is a nationwide programme to assess national health and nutritional status in Korea. A population-based study was conducted to analyse the relationship between self-reported asthma and exogenous hormones using the KNHANES between 2007 and 2012.

PARTICIPANTS

The study sample included 6874 premenopausal and 4912 postmenopausal women aged 30-65.

OUTCOME MEASURES

KNHANES data comprised health interviews and physical examinations. Questionnaires regarding asthma, reproductive factors and exogenous hormones were included.

RESULTS

Among postmenopausal women, 3.4% reported doctor-diagnosed asthma. Hormone replacement therapy (HRT) was associated with increased odds of doctor-diagnosed asthma (OR 1.56; 95% CI 1.04 to 2.35), while the association between HRT and wheeze in the last 1 year was not significant (OR 1.37; 95% CI 0.95 to 1.96). In premenopausal women, the prevalence of asthma was 2.3%. Use of oral contraceptives (OCs) was associated with an increased odds of doctor-diagnosed asthma (OR 1.67; 95% CI 1.01 to 2.76) and wheeze in the last 1 year (OR 1.88; 95% CI 1.31 to 2.69). These associations were dominant among non-obese women (body mass index <25 kg/m²; OR 2.36; 95% CI 1.34 to 4.17 for asthma and OR 2.15; 95% CI 1.43 to 3.23 for wheeze).

CONCLUSIONS

HRT and OCs were associated with increased asthma in postmenopausal and premenopausal women, respectively. The association between OC use and asthma was strong in non-obese premenopausal women.

Sex-based differences in factors associated with bronchial hyperresponsiveness in adolescents with childhood asthma

BACKGROUND

Bronchial hyperresponsiveness (BHR), an important physiological feature of asthma, is a prognostic marker of childhood asthma.

PURPOSE

We aimed to investigate the factors associated with BHR in adolescents with childhood asthma.

METHODS

Two hundred and fifteen adolescents (≥13 years of age; 149 males, 66 females) who were diagnosed with asthma during childhood were enrolled, underwent methacholine challenge tests, and were divided into the BHR group (<25 mg/mL of provocation concentration causing a 20% fall in forced expiratory volume in 1 second [FEV1] [PC20], n=113) or non-BHR group (≥25 mg/mL of PC20, n=102). We examined longitudinal changes in BHR and the risk factors for its persistence in the 108 adolescents for whom baseline data, including methacholine PC20 at age 6 years, were available. Multivariate logistic regression analyses were performed to assess the factors associated with BHR in adolescents.

RESULTS

Mold sensitization (adjusted odds ratio [aOR], 5.569; P=0.005) and increased blood eosinophil count (aOR, 1.002; P=0.026) were independently associated with BHR in boys but not girls. The odds of BHR decreased by 32% with each 1-year increase in age in boys (aOR, 0.683; P=0.010) but not girls. A reduced FEV1/forced vital capacity ratio (<90%) was independently related with BHR in female patients only (aOR, 7.500; P=0.007). BHR decreased with age throughout childhood. A low methacholine PC20 at age 6 years was independently associated with persistent BHR throughout childhood in male and female patients, whereas early mold sensitization was a risk factor for persistent BHR in male patients only (aOR, 7.718; P=0.028).

CONCLUSION

Our study revealed sex-specific differences in the factors associated with BHR in adolescents with childhood asthma. Our findings suggest the risk factors that might affect asthma transition from childhood to adolescence and adulthood.

Association between the timing of asthma diagnosis and medication use during pregnancy

STUDY OBJECTIVE

To assess whether asthma medication use during pregnancy differs in women newly diagnosed with asthma early in pregnancy (first 19 weeks of pregnancy) compared to those newly diagnosed up to 2 years pre-pregnancy.

DESIGN

A retrospective population-based cohort study.

DATA SOURCE

To conduct this study, we used the Quebec Asthma and Pregnancy Database (QAPD) constructed by linking two administrative health databases from the province of Quebec (Canada): the Régie de l'Assurance Maladie du Québec and Maintenance et Exploitation des Données pour l'Étude de la Clientèle Hospitalière databases.

PATIENTS

A cohort comprising pregnant women newly diagnosed with asthma at any time in the 2 years prior to pregnancy or during the first 19 weeks of pregnancy was selected from the QAPD.

MEASUREMENTS AND MAIN RESULTS

We assessed the number of filled prescriptions of inhaled corticosteroids (ICS), ICS/long-acting β2 agonists (LABA), and short-acting β2 agonists (SABA), as well as the number of days' supply of oral corticosteroid (OCS) from the 20^th week of pregnancy until delivery. Poisson regression was used to compare the rates of asthma medication use in women diagnosed pre-pregnancy versus early in pregnancy. The cohort included 1731 women newly diagnosed with asthma pre-pregnancy and 359 women newly diagnosed with asthma early in pregnancy. Women diagnosed early in pregnancy were more likely to use ICS (adjusted rate ratio: 1.9, 95% confidence interval (CI): 1.6-2.3) and SABA (adjusted rate ratio: 2.0, 95% CI: 1.7-2.4) from the 20th week of pregnancy until delivery than those newly diagnosed pre-pregnancy. No significant differences were observed in the use of ICS/LABA [adjusted rate ratio: 0.9, 95% CI: 0.7-1.3] and OCS [adjusted rate ratio: 0.8, 95% CI: 0.6-1.2].

CONCLUSION

The higher use of ICS and SABA observed in women newly diagnosed with asthma early in pregnancy may suggest a more persistent asthma phenotype caused by pregnancy-triggered hormonal changes.

Timing of Maternal Asthma Diagnosis in Relation to Adverse Perinatal Outcomes

BACKGROUND

It is unclear if asthma diagnosed during pregnancy puts the fetus at a higher risk of poor perinatal outcomes than pre-existing asthma.

OBJECTIVE

To assess if the risks of prematurity, major malformations, and small-for-gestational age (SGA) are higher in women with asthma diagnosed during versus pre-pregnancy.

METHODS

We retrospectively analyzed a cohort of pregnant women aged ≥15 years with and without incident asthma, constructed from health administrative databases. Follow-up began 24 months before pregnancy onset (cohort entry) and ended at delivery. Incident asthma was defined as a first diagnosis among those without asthma in the 8 years before cohort entry. Time was classified into pre-pregnancy and each trimester until delivery. We fit inverse probability weighted Poisson models to estimate marginal relative risks (RRs) for prematurity (delivery <37th week), major malformations, and SGA (birth weight <10th percentile) comparing women with and without asthma, assessing the asthma timing of diagnosis interaction term via a Wald test.

RESULTS

In a cohort of 122,880 deliveries, the increased risk of prematurity, but not SGA, due to incident asthma was higher in those diagnosed during the second (RR, 1.34; 95% confidence interval [CI], 1.08-1.65; Wald P = .05) and third (RR, 1.93; 95% CI, 1.62-2.29; Wald P < .01) trimesters relative to pre-pregnancy (RR, 1.06; 95% CI, 0.98-1.15). A trend toward an increased risk of major malformations was observed in those diagnosed during the first trimester (RR, 1.18; 95% CI, 0.94-1.49; Wald P = .15) than pre-pregnancy (RR, 0.99; 95% CI, 0.92-1.07).

CONCLUSIONS

Asthma diagnosed during, versus before, pregnancy was associated with a greater prematurity risk, suggesting an important role of preconception and prenatal screening.

Sex Steroid Hormones and Asthma in a Nationwide Study of U.S. Adults

Rationale: Women have a higher burden of asthma than men. Although sex hormones may explain sex differences in asthma, their role is unclear.Objectives: To examine sex hormone levels and asthma in adults.Methods: Cross-sectional study of serum levels of free testosterone and estradiol and current asthma in 7,615 adults (3,953 men and 3,662 women) aged 18-79 years who participated in the 2013-2014 and 2015-2016 U.S. National Health and Nutrition Examination Survey. Logistic regression was used for the multivariable analysis of sex hormones and current asthma, which was conducted separately in women and men.Measurements and Main Results: Free testosterone levels in the fourth quartile were associated with lower odds of current asthma in women (odds ratio [OR] for the fourth quartile [Q4] vs. Q1, 0.56; 95% confidence interval [CI], 0.39-0.80). Given an interaction between obesity and sex hormones on current asthma, we stratified the analysis by obesity. In this analysis, elevated free testosterone (OR for Q4 vs. Q1, 0.59; 95% CI, 0.37-0.91) and estradiol (OR for Q4 vs. Q1, 0.43; 95% CI, 0.23-0.78) levels were associated with reduced odds of current asthma in obese women, and an elevated serum estradiol was associated with lower odds of current asthma in nonobese men (OR for Q4 vs. Q1, 0.44; 95% CI, 0.21-0.90).Conclusions: Our findings suggest that sex hormones play a role in known sex differences in asthma in adults. Moreover, our results suggest that obesity modifies the effects of sex hormones on asthma in adults.

Objective measurement of nocturnal cough in infants with acute bronchiolitis

OBJECTIVES

The objective measurement of the cough severity and the assessment of the pattern of nocturnal coughing could be useful in the treatment of respiratory diseases in children.

STUDY DESIGN

In children with respiratory syncytial virus (RSV)-induced acute bronchiolitis, coughs were recorded using our original system with a microphone and accelerometer, and analyzed using our customized software program. The number of coughs in every 30-minute interval was measured in patients with acute bronchiolitis (n = 20), and their results were compared with those of infants with asthma exacerbation (n = 16).

RESULTS

The cough count in children with acute bronchiolitis (median: 108.0/night) was almost as high as that in children with asthma exacerbation (median: 119/night). However, the time-dependent pattern of overnight cough was different in infants with acute bronchiolitis and those with asthma exacerbation. In the infants with asthma exacerbation, cough frequency significantly increased while falling asleep and waking up as compared to midnight (p < 0.001 and p < 0.001, respectively). However, these differences were not found in infants with acute bronchiolitis.

CONCLUSIONS

Our data demonstrated that the number of coughing events due to acute bronchiolitis was similar to that of acute asthma exacerbation, although the acute bronchiolitis did not show a characteristic overnight cough pattern.

Life-long endogenous estrogen exposure is associated with prevalence of allergic rhinitis in postmenopausal women

OBJECTIVES

The aim of the study was to investigate the influence of life-long endogenous estrogen exposure on prevalence of chronic rhinitis including allergic rhinitis (AR) in the postmenopausal period.

METHODS

In this cross-sectional study, a total of 3,043 postmenopausal women who participated in the Korea National Health and Nutrition Examination Survey V were included. Participants with symptoms including sneezing, rhinorrhea, nasal obstruction, or nasal itching were considered to have chronic rhinitis. In subgroup analysis, the AR group comprised participants with rhinitis with positive findings in at least one of three specific immunoglobulin E. Univariable and multivariable logistic analyses were performed to evaluate the relationship between rhinitis and estrogen-related factors including age at menarche, age at menopause, age at first delivery, parity, and duration of breast-feeding.

RESULTS

Participants with chronic rhinitis (17.6%) had higher parity (odd ratio [OR] = 1.17, P = 0.0135) and shorter duration of breast-feeding (OR = 0.98, P = 0.0388) than controls. In subgroup analysis, participants with AR (7.1%) had younger age at menarche (OR = 0.56, P = 0.0028) and older age at menopause (OR = 1.42, P = 0.0060) after adjustment of confounding factors. There was a positive association between age at menopause and specific immunoglobulin E for both cockroach (OR = 1.38, P = 0.0132) and dogs (OR = 1.38, P = 0.0302). Longer postmenopausal duration was positively associated with cockroach allergen sensitization (OR = 1.25, P = 0.201).

CONCLUSIONS

Longer duration of reproductive period was associated with higher prevalence of AR and aeroallergen sensitization in the postmenopausal period. Moreover, cockroach allergen sensitization was associated with a longer postmenopausal period.

Prevalence of asthma among the adult general population of five Middle Eastern countries: results of the SNAPSHOT program

BACKGROUND

Asthma is a common chronic respiratory disease leading to morbidity, mortality and impaired quality of life worldwide. Information on asthma prevalence in the Middle East is fragmented and relatively out-dated. The SNAPSHOT program was conducted to obtain updated information.

METHODS

SNAPSHOT is a cross-sectional epidemiological program carried out in five Middle Eastern countries (Egypt, Turkey, Kuwait, Saudi Arabia, and the United Arab Emirates, the latter three grouped into a Gulf cluster) to collect data on asthma, allergic rhinitis, benign prostatic hyperplasia and bipolar disorder. The survey was carried out by telephone in a random sample of the adult general population with quotas defined according to country demographics. The analysis presented in this paper focuses on asthma. Subjects were screened for asthma based on criteria from the global Asthma Insights and Reality studies. Current prevalence (last 12 months) was estimated. Multivariate logistic regression analyses were used to investigate risk factors related to asthma and the association with allergic rhinitis and other co-morbidities. Quality of life was assessed using the three-level EQ-5D questionnaire.

RESULTS

2124 out of the 33,486 subjects enrolled in the SNAPSHOT program fulfilled the criteria for asthma. The adjusted prevalence of asthma ranged from 4.4% [95% CI: 4.0-4.8%] in Turkey, to 6.7% [95% CI: 6.2-7.2%] in Egypt and 7.6% [95% CI: 7.1-8.0%] in the Gulf cluster. Prevalence was higher (p < 0.0001) in women than men and increased with age (p < 0.0001). Co-morbidities occurred more frequently in asthma subjects compared to the non-asthma population (38% vs. 15% p < 0.0001). Subjects with asthma reported a lower (p < 0.0001) EQ-VAS score (68.2 ± 22.9) compared to the general population (78.1 ± 17.5). The risk factors associated with asthma were age, gender, country, and certain co-morbidities, namely respiratory, cardiovascular, gastrointestinal, nervous, and neurological diseases.

CONCLUSION

The observed adjusted prevalence of asthma in the Middle East ranges from 4.4% to 7.6%, which is comparatively lower than the reported prevalence in Europe and North America. Asthma has a negative impact on quality of life, and is associated with high levels of co-morbid diseases, indicating a need for physicians to check for co-morbidities and ensure they are managed correctly in all asthma patients.

Gender aspects and influence of hormones on bronchial asthma - Secondary publication and update

There is good evidence for gender-specific differences in asthma regarding all affected areas, from intra- to extra-cellular mediators to the whole organ structure und functioning of the lung. These result from complex, in parts synergistic, in other parts opposing, effects - especially of female sex hormones, and rather protective effects of male hormones against asthma, which include effects on the cellular immune system. Additionally, there are gender differences of sociocultural origin, regarding presentation, doctor's diagnosis and treatment of asthma symptoms, as well as the undertaken coping strategies concerning the female or male patient's complaints. Taking into account gender-specific differences in asthma would contribute to improved individual diagnosis and therapies.

A functional IFN-λ4-generating DNA polymorphism could protect older asthmatic women from aeroallergen sensitization and associate with clinical features of asthma

Lambda interferons (IFNLs) have immunomodulatory functions at epithelial barrier surfaces. IFN-λ4, a recent member of this family is expressed only in a subset of the population due to a frameshift-causing DNA polymorphism rs368234815. We examined the association of this polymorphism with atopy (aeroallergen sensitization) and asthma in a Polish hospital-based case-control cohort comprising of well-characterized adult asthmatics (n = 326) and healthy controls (n = 111). In the combined cohort, we saw no association of the polymorphism with asthma and/or atopy. However, the IFN-λ4-generating ΔG allele protected older asthmatic women (>50 yr of age) from atopic sensitization. Further, ΔG allele significantly associated with features of less-severe asthma including bronchodilator response and corticosteroid usage in older women in this Polish cohort. We tested the association of related IFNL locus polymorphisms (rs12979860 and rs8099917) with atopy, allergic rhinitis and presence/absence of asthma in three population-based cohorts from Europe, but saw no significant association of the polymorphisms with any of the phenotypes in older women. The polymorphisms associated marginally with lower occurrence of asthma in men/older men after meta-analysis of data from all cohorts. Functional and well-designed replication studies may reveal the true positive nature of these results.

Eosinophils in Autoimmune Diseases

Eosinophils are multifunctional granulocytes that contribute to initiation and modulation of inflammation. Their role in asthma and parasitic infections has long been recognized. Growing evidence now reveals a role for eosinophils in autoimmune diseases. In this review, we summarize the function of eosinophils in inflammatory bowel diseases, neuromyelitis optica, bullous pemphigoid, autoimmune myocarditis, primary biliary cirrhosis, eosinophilic granulomatosis with polyangiitis, and other autoimmune diseases. Clinical studies, eosinophil-targeted therapies, and experimental models have contributed to our understanding of the regulation and function of eosinophils in these diseases. By examining the role of eosinophils in autoimmune diseases of different organs, we can identify common pathogenic mechanisms. These include degranulation of cytotoxic granule proteins, induction of antibody-dependent cell-mediated cytotoxicity, release of proteases degrading extracellular matrix, immune modulation through cytokines, antigen presentation, and prothrombotic functions. The association of eosinophilic diseases with autoimmune diseases is also examined, showing a possible increase in autoimmune diseases in patients with eosinophilic esophagitis, hypereosinophilic syndrome, and non-allergic asthma. Finally, we summarize key future research needs.

Risk factors for incident asthma and COPD in a cohort of young adults

INTRODUCTION

The aim of the study was to describe potential shared risk factors for incident asthma and COPD in a population-based, 9-year follow-up study.

METHODS

From a cohort of 1191 individuals, aged 20-44, who participated in baseline survey including spirometry, bronchial challenge, and skin prick test (SPT) 742 subjects (62%) were reexamined at follow-up in 2012-2014.

RESULTS

A total of 27 incident cases of asthma and 22 cases of COPD were identified at follow-up corresponding to an incidence rate of 5.8 (95% CI 3.9-8.4) and 3.5 (2.2-5.3) per 1000 person years, respectively. Among the identified COPD cases a total of 12 were Asthma-COPD Overlap Syndrome (ACOS). Atopy defined by positive SPT was a risk factor for asthma in males (OR 7.54; 95% CI 1.24-45.90), whereas risk factors in females were nasal allergy (3.81; 1.20-12.11), FEV₁ <100% predicted (3.96; 1.07-14.62) and parental asthma (3.06; 1.00-9.40). Risk factors for COPD in males were bronchial hyperresponsiveness (23.13; 1.41-380.50) and FEV₁ <100% predicted (all male cases had FEV₁ <100% predicted) and in females current smoking (3.34; 1.16-9.59) and asthma at baseline (5.21; 1.48-18.34).

CONCLUSIONS

No shared risk factors for incident asthma and COPD were found. Despite low power when stratifying by sex risk factors for incident asthma and COPD emphasize considerable gender differences.

Heterogeneity of obesity-asthma association disentangled by latent class analysis, the SAPALDIA cohort

Although evidence for the heterogeneity of asthma accumulated, consensus for definitions of asthma phenotypes is still lacking. Obesity may have heterogeneous effects on various asthma phenotypes. We aimed to distinguish asthma phenotypes by latent class analysis and to investigate their associations with different obesity parameters in adults using a population-based Swiss cohort (SAPALDIA). We applied latent class analysis to 959 self-reported asthmatics using information on disease activity, atopy, and age of onset. Associations with obesity were examined by multinomial logistic regression, after adjustments for age, sex, smoking status, educational level, and study centre. Body mass index, percent body fat, waist hip ratio, waist height ratio, and waist circumference were used as obesity measure. Four asthma classes were identified, including persistent multiple symptom-presenting asthma (n = 122), symptom-presenting asthma (n = 290), symptom-free atopic asthma (n = 294), and symptom-free non-atopic asthma (n = 253). Obesity was positively associated with symptom-presenting asthma classes but not with symptom-free ones. Percent body fat showed the strongest association with the persistent multiple symptom-presenting asthma. We observed heterogeneity of associations with obesity across asthma classes, indicating different asthma aetiologies.

Association between menarche and increased bronchial hyper-responsiveness during puberty in female children and adolescents

PURPOSE

Bronchial hyper-responsiveness (BHR) is a key feature of asthma. The degree of BHR in children may be altered by several factors. We evaluated the prevalence of BHR according to age and gender in pediatric and adolescent population and analyzed the associated factors for gender differences.

METHODS

Among the 2,067 subjects, methacholine challenge tests were performed in 1,820 children from one elementary and one middle school in Seoul, Korea. A total of 1,725 subjects between 6 and 14 years old were included in the analysis. The prevalence of BHR, defined as a provocative concentration that induced a 20% reduction of FEV₁ (PC₂₀ ) that was less than 8 mg/ml, was evaluated according to age and gender. Gender differences associated with BHR prevalence at each age were calculated and multiple logistic regression analyses were performed to identify factors associated with BHR by gender.

RESULTS

The prevalence of BHR (PC₂₀  ≤ 8 mg/ml) for each gender decreased with age (P < 0.001). Although the prevalence of BHR linearly decreased in males with age, females showed an increase after 11 years of age. BHR in males was associated with a younger age (aOR, 0.797; 95%CI, 0.678-0.925), a higher blood eosinophil counts (%) (aOR, 1.160; 95%CI, 1.047-1.284), atopy (aOR, 2.091; 95%CI, 1.003-4.359), and a lower FEV₁ /FVC ratio (aOR, 0.947; 95%CI, 0.901-0.995), and FEF_25-75% (aOR, 0.980; 95%CI, 0.961-0.999). In females, BHR was significantly associated with a younger age (aOR, 0.845; 95%CI, 0.747-0.957), lower FEV₁ (%) (aOR, 0.961; 95%CI, 0.938-0.984), and menarche (aOR, 3.674; 95%CI, 1.226-11.012).

CONCLUSION

BHR declined with age in the Korean pediatric population. A younger age and reduced lung function were common factors related to BHR in both genders. Additionally, atopy was related to BHR in males, whereas sexual maturation was related to BHR in females. These findings have important clinical implications for evaluating of childhood BHR and asthma related to gender. Pediatr Pulmonol. 2016;51:1040-1047. © 2016 Wiley Periodicals, Inc.

Objective measurement of frequency and pattern of nocturnal cough in children with asthma exacerbation

BACKGROUND

Although a number of patients with asthma report experiencing persistent cough during sleep, it has not yet been objectively investigated.

OBJECTIVE

To classify cough severity and evaluate a characteristic pattern of cough frequency in children with asthma using an objective cough monitoring system.

METHODS

An objective cough monitoring system that specialized in children was used to measure cough frequency and nocturnal cough patterns. Coughs were recorded with microphone and accelerometer and analyzed using a customized software program. The number of nocturnal coughs and the pattern of cough frequency in 30-minute intervals were measured along with the severity of each asthma exacerbation, and the results were compared with children without asthma.

RESULTS

The total overnight cough count of 34 children with asthma was higher than that of 15 children without asthma (P < .001). The total overnight cough count in children with severe asthma exacerbation was higher than that in children with moderate asthma exacerbation (P < .05). The cough counts were significantly increased at the time of falling asleep and waking. This pattern was not observed in children without asthma. The total cough counts and cough patterns in children with asthma were not affected by sex, age, cause of asthma exacerbation, or therapy.

CONCLUSION

Our data indicate huge cough counts and characteristic nocturnal cough patterns in children with asthma. Objective and precise cough monitoring is useful for the management of childhood asthma.

Visceral adiposity is associated with cytokines and decrease in lung function in women with persistent asthma

Abdominal obesity is associated with a risk of cardiovascular diseases, metabolic syndrome and decreased lung function. However, it is not known whether asthma control is influenced by the accumulation of adipose tissue in the various abdominal compartments.

OBJECTIVE

To determine associations among abdominal adiposity distribution, asthma control, lung function and cytokines in women.

METHODS AND DESIGN

In this cross-sectional study of asthmatic women, data on demographic variables, comorbid conditions, disease history, anthropometric and spirometric measurements were collected. Subcutaneous (SAT) and visceral (VAT) adipose tissues were measured by ultrasound, and the steatosis level was obtained. Asthma control was assessed according to Global Initiative for Asthma (GINA) criteria. Atopy was defined on the basis of allergen-specific Immunoglobulin E and/or skin prick testing. Cytokine levels were determined using enzyme-linked immunosorbant assays (ELISAs).

RESULTS

Eighty-three asthmatic women were included, 37% of whom had uncontrolled asthma. After controlling for variables, a negative association between asthma control and VAT and the VAT/SAT ratio was observed. VAT was negatively associated with respiratory parameters after controlling for explanatory variables. In an adjusted model, body mass index (BMI) and SAT were inversely associated with the adiponectin serum level and VAT was associated with the interleukin 6 level. In conclusion, visceral obesity was negatively associated with asthma control and lung function; and positively associated with increased levels of interleukin 6 in women. We hypothesize that women should be studied as a separate group, and we suggest further studies with a control group to know if the uncontrolled asthmatic group is directly affected by visceral adipose inflammatory markers.

Expression of Sex Steroid Hormone Receptors in Vagal Motor Neurons Innervating the Trachea and Esophagus in Mouse

The medullary vagal motor nuclei, the nucleus ambiguus (NA) and dorsal motor nucleus of the vagus (DMV), innervate the respiratory and gastrointestinal tracts. We conducted immunohistochemical analysis of expression of the androgen receptor (AR) and estrogen receptor α (ERα), in relation to innervation of the trachea and esophagus via vagal motor nuclei in mice. AR and ERα were expressed in the rostral NA and in part of the DMV. Tracing experiments using cholera toxin B subunit demonstrated that neurons of vagal motor nuclei that innervate the trachea and esophagus express AR and ERα. There was no difference in expression of sex steroid hormone receptors between trachea- and esophagus-innervating neurons. These results suggest that sex steroid hormones may act on vagal motor nuclei via their receptors, thereby regulating functions of the trachea and esophagus.

The influence of sensitization on mechanisms of organophosphorus pesticide-induced airway hyperreactivity

We previously demonstrated that antigen sensitization increases vulnerability to airway hyperreactivity induced by the organophosphorus pesticide (OP) parathion. Sensitization also changes the mechanism of parathion-induced airway hyperreactivity to one that is dependent on IL-5. To determine whether this effect can be generalized to other OPs, and to other classes of pesticides, we measured airway responsiveness to vagal stimulation or intravenous acetylcholine in nonsensitized and ovalbumin-sensitized guinea pigs 24 hours after a single subcutaneous injection of the OPs diazinon or chlorpyrifos, or the pyrethroid permethrin. Sensitization exacerbated the effects of chlorpyrifos on bronchoconstriction in response to vagal stimulation or intravenous acetylcholine. Pretreatment with function-blocking IL-5 antibody prevented chlorpyrifos-induced airway hyperreactivity in sensitized, but not in nonsensitized, guinea pigs. In sensitized guinea pigs, blocking IL-5 decreased eosinophil activation, as measured by decreased eosinophil major basic protein in the trachea. In contrast, sensitization did not alter diazinon-induced airway hyperreactivity, and permethrin did not cause airway hyperreactivity in either nonsensitized or sensitized guinea pigs. None of the pesticides affected inflammatory cells in the bronchoalveolar lavage fluid or blood. We have previously shown that three different OPs cause airway hyperreactivity via loss of neuronal M2 muscarinic receptor function. Similar to parathion, but unlike diazinon, the mechanism of chlorpyrifos-induced airway hyperreactivity is changed by sensitization. Thus, OP-induced airway hyperreactivity is dependent on sensitization status and on the OP used, which may influence therapeutic approaches.

Hormonal contraception increases risk of asthma among obese but decreases it among nonobese subjects: a prospective, population-based cohort study

Epidemiological data on asthma suggest a sex difference that varies with age. Hormonal effects have been suggested as a possible explanation for these differences but there is a scarcity of evidence on these relationships. Our objective was to examine the relationship between reproductive factors and asthma risk among females and to examine whether body mass index (BMI) modifies this relationship.

Female participants in the 2004 fifth decade follow-up postal survey of the Tasmanian Longitudinal Health Study formed the study population. Reproductive history and data on hormonal contraceptive (HC) use were collected on 2764 females. Multiple logistic regression was used to assess the association between the reproductive factors and current asthma.

The mean age of participants was 43 years and the prevalence of middle-aged current asthma was 12.8%. Females with very early menarche (≤10 years) had higher odds of middle-aged current asthma (OR 1.91, 95% CI 1.14–3.2). Pregnancy history (number of births and age at first pregnancy) were not associated with current asthma risk at 44 years. Ever having used HCs, years of use and age started using HCs were not individually associated with current asthma risk. However, body mass index significantly modified the relationship between HC use and asthma. We found increasing years of pill use was associated with a significantly increased risk of current asthma in overweight/obese women but a reduced risk in normal weight women (interaction p=0.015).

Hormonal effects from use of HCs and early menarche may contribute to the sex differential in asthma risk. Our findings suggest that in obese women with a history of long-term HC use may be at an increased risk of chronic respiratory disease, and regular monitoring for asthma and asthma symptoms may be recommended.

Overweight or obese women are at increased risk of asthma if they use hormonal contraceptives for extended periodshttp://ow.ly/SwY8p

Association Between Obesity, Abdominal Obesity, and Adiposity and the Prevalence of Atopic Dermatitis in Young Korean Adults: the Korea National Health and Nutrition Examination Survey 2008-2010

PURPOSE

Whether obesity is a risk factor for atopic dermatitis (AD) remains unclear. The aim of the present study was to investigate the association between obesity and AD in Korean young adults.

METHODS

We included nationally representative data of 5,202 Korean adults aged 19-40 years, obtained from the cross-sectional Korea National Health and Nutrition Examination Survey 2008-2010.

RESULTS

Single (unmarried) status was more frequently observed in AD patients (male, [P=0.0002] and female, [P<0.0001]). AD prevalence exhibited a U-shape trend in relation to body mass index (BMI), waist circumference (WC), and total body fat (BF) percentage, especially in young adult women. Women with BMI ≥25 kg/m², WC ≥80 cm, and highest quartile (Q4) of total BF percentage had the highest prevalence of AD. The odds ratio (OR) for participants with both BMI ≥25 kg/m² and WC ≥80 cm was 3.29 (95% confidence interval [CI] 1.71-3.55); therefore, having both general and abdominal obesity was considered a prominent risk factor for AD in young women. After adjustment for confounding factors, including age, smoking, alcohol drinking, exercise, vitamin D, income level, and single status, high BMI (≥30 kg/m²) (OR=4.08, 95% CI: 1.53-10.93), high WC (≥80 cm) (OR=2.05, 95% CI: 1.07-3.94), and high BF percentage (Q4) (OR=2.10, 95% CI: 1.24-3.57) were shown to be significantly associated with AD in young adult women.

CONCLUSIONS

In this large-scale nation-wide study of Korean adults, obesity was positively related to the presence of AD in women. Our findings suggest that weight management may help prevent AD.

Central obesity and other factors associated with uncontrolled asthma in women

Background

Asthma remains an uncontrolled disease. The Comorbidities, particularly obesity, and several other factors have been identified as being individually associated with asthma control, and these factors vary among different countries and between sexes. Studies have suggested that the harmful effects of these factors are greatest among women. The aim of the present study was to identify associated factors with uncontrolled asthma in women at the outpatient clinic of a Federal University Hospital in Rio de Janeiro, Brazil.

Methods

Cross-sectional study with asthmatic women, older than 18 years old. All subjects were included according to stringent criteria. The study used a structured questionnaire with data about demographic variables, education level, comorbid conditions, and disease history. Anthropometric and spirometric measurements were obtained. Asthma control was assessed by three different tools: the Asthma Control Test (ACT), the Asthma Control Questionnaire (ACQ) and the Global Initiative for Asthma (GINA) criteria.

Results

A total of 124 women were included, and 57%, 38% and 21% were totally controlled according to ACT, ACQ and GINA criteria, respectively. A total of 31.5% were obese. According to the CI (Conicity Index) and WC (waist circumference) respectively, 84% and 68% were centrally obese. There was no association between asthma control and age, education, duration of the disease or BMI (Body Mass Index) in the three models, but there was a significant association between central obesity and asthma control with the ACQ and GINA assessment tools, controlling for explanatory variables such as GERD (gastroesophageal reflux disease). Pre-bronchodilator percent predicted forced expiratory volume in one second (FEV₁) and forced vital capacity (FVC) were significantly associated with age and FVC was also associated with central obesity.

Conclusions

Asthma remains uncontrolled in women despite treatment, and central obesity seems to have a negative influence on the control of the disease. We believe that women should be studied as a separate group and suggest prospective studies with assessment of fat distribution and biomarkers, controlling for possible comorbidities associated with asthma control.

Allergen screening bioassays: recent developments in lab-on-a-chip and lab-on-a-disc systems

Allergies occur when a person's immune system mounts an abnormal response with or without IgE to a normally harmless substance called an allergen. The standard skin-prick test introduces suspected allergens into the skin with lancets in order to trigger allergic reactions. This test is annoying and sometimes life threatening. New tools such as lab-on-a-chip and lab-on-a-disc, which rely on microfabrication, are designed for allergy testing. These systems provide benefits such as short analysis times, enhanced sensitivity, simplified procedures, minimal consumption of sample and reagents and low cost. This article gives a summary of these systems. In particular, a cell-based assay detecting both the IgE- and non-IgE-type triggers through the study of degranulation in a centrifugal microfluidic system is highlighted.

Obesity - a promoter of allergy?

The prevalence of both obesity and allergy has been increasing throughout the world, leading to the hypothesis that the two are linked to one another. This overview summarizes the results of 34 studies from 2002 to 2012 that investigated a possible contributing effect of increasing body mass on the development and prevalence of various atopic diseases. Obesity was found to clearly affect bronchial asthma. However, the correlation was stronger in the nonatopic asthma phenotype. Obesity was found to be associated with the development of atopic dermatitis in children only. No clear association was found between obesity and the prevalence of allergic rhinitis or allergic conjunctivitis or increased sensitization to food allergens. This review sums up our study results and discusses a possible role of obesity in the promotion of allergy and asthma.

Characteristics of perimenstrual asthma and its relation to asthma severity and control: data from the Severe Asthma Research Program

BACKGROUND

Although perimenstrual asthma (PMA) has been associated with severe and difficult-to-control asthma, it remains poorly characterized and understood. The objectives of this study were to identify clinical, demographic, and inflammatory factors associated with PMA and to assess the association of PMA with asthma severity and control.

METHODS

Women with asthma recruited to the National Heart, Lung, and Blood Institute Severe Asthma Research Program who reported PMA symptoms on a screening questionnaire were analyzed in relation to basic demographics, clinical questionnaire data, immunoinflammatory markers, and physiologic parameters. Univariate comparisons between PMA and non-PMA groups were performed. A severity-adjusted model predicting PMA was created. Additional models addressed the role of PMA in asthma control.

RESULTS

Self-identified PMA was reported in 17% of the subjects (n = 92) and associated with higher BMI, lower FVC % predicted, and higher gastroesophageal reflux disease rates. Fifty-two percent of the PMA group met criteria for severe asthma compared with 30% of the non-PMA group. In multivariable analyses controlling for severity, aspirin sensitivity and lower FVC % predicted were associated with the presence of PMA. Furthermore, after controlling for severity and confounders, PMA remained associated with more asthma symptoms and urgent health-care utilization.

CONCLUSIONS

PMA is common in women with severe asthma and associated with poorly controlled disease. Aspirin sensitivity and lower FVC % predicted are associated with PMA after adjusting for multiple factors, suggesting that alterations in prostaglandins may contribute to this phenotype.

Asthma and the menopause: a systematic review and meta-analysis

OBJECTIVE

To review the available literature to determine whether the menopausal transition is associated with asthma incidence.

METHODS

We performed a systematic review and meta-analysis of cohort and cross-sectional studies providing a definition/assessment of menopausal status, incidence or prevalence of a defined diagnosis of asthma, and providing a measure of the association or of menopausal state and asthma or enough data for a calculation of this association. Where possible these meta-analytic estimates were also stratified by intake of menopausal hormone therapy (MHT).

RESULTS

Of 76 potentially relevant articles, 8 studies met the inclusion criteria and were included in the review, and 6 in the meta-analysis. There was heterogeneity across studies: four studies reported slightly increased prevalence rates of asthma in post-menopause, one large cohort yielded a lower asthma incidence and one cross-sectional study a lower prevalence in post-menopause. Overall, the meta-analysis showed no significant association between menopause and asthma rates. When stratifying by use of MHT, the association between menopause and asthma rates was increased in women reporting use of MHT (RR 1.32, 95%CI 1.01-1.74), but not in women not using MHT.

CONCLUSION

We found no significant association of menopause with asthma prevalence or incidence except for women reporting use of MHT. However, these findings result from a small number of studies, including only 1 large cohort with incidence rates for pre- as well as post-menopause. Further studies are needed addressing more closely subgroup analyses and a possible modification of the association of menopause and asthma by MHT.

Asthma phenotypes: the evolution from clinical to molecular approaches

Although asthma has been considered as a single disease for years, recent studies have increasingly focused on its heterogeneity. The characterization of this heterogeneity has promoted the concept that asthma consists of multiple phenotypes or consistent groupings of characteristics. Asthma phenotypes were initially focused on combinations of clinical characteristics, but they are now evolving to link biology to phenotype, often through a statistically based process. Ongoing studies of large-scale, molecularly and genetically focused and extensively clinically characterized cohorts of asthma should enhance our ability to molecularly understand these phenotypes and lead to more targeted and personalized approaches to asthma therapy.

Macrophage colony stimulating factor and monocyte chemoattractant protein 2 are elevated in intrinsic asthmatics

BACKGROUND

Intrinsic asthma, etiology unknown, occurs later in life, mostly in females. It is associated with nasal polyps and massive eosinopillic infiltration of the respiratory mucous membrane, aspirin intolerance and steroid dependence. The aim of the study was to determine the cytokine and chemokine profile in sera of intrinsic asthmatics and control subjects.

METHODS

Blood was taken from 10 intrinsic asthmatic female and 12 control female subjects. Expression profile of 42 different cytokines and chemokines were measured using a microarray composed of antibodies against the cytokines and chemokines. Complete blood count and C-reactive protein were measured, to assess the state of inflammation in both groups.

RESULTS

We have identified Macrophage Colony Stimulating Factor, a proinflammatory cytokine and Monocyte Chemoattractant Protein 2, a CC chemokine as having significantly higher expression levels in intrinsic asthmatic subjects compared to controls (341.71±31.28 SEM Signal intensity) versus (247.97±28.09 SEM Signal intensity), p=0.036 and (397.07±38.19 SEM Signal intensity) versus (311.33±28.76 SEM Signal intensity), p=0.036, respectively. There were no significant differences in the other cytokines and chemokines measured nor were there any differences in the inflammatory measurements between the two groups except for eosinophil counts, the hall mark of intrinsic asthma.

CONCLUSION

Macrophage Colony Stimulating Factor and Monocyte Chemoattractant Protein are elevated in sera of intrinsic asthmatics compared to normal controls. These cytokines may have a critical role in the inflammatory pathology of intrinsic asthma.

Developments in the field of allergy in 2009 through the eyes of Clinical and Experimental Allergy

In 2009 the journal published in the region of 200 papers including reviews, editorials, opinion pieces and original papers that ran the full gamut of allergic disease. It is instructive to take stock of this output to determine patterns of interest and where the cutting edge lies. We have surveyed the field of allergic disease as seen through the pages of Clinical and Experimental Allergy (CEA) highlighting trends, emphasizing notable observations and placing discoveries in the context of other key papers published during the year. The review is divided into similar sections as the journal. In the field of Asthma and Rhinitis CEA has contributed significantly to the debate about asthma phenotypes and expressed opinions about the cause of intrinsic asthma. It has also added its halfpennyworth to the hunt for meaningful biomarkers. In Mechanisms the considerable interest in T cell subsets including Th17 and T regulatory cells continues apace and the discipline of Epidemiology continues to invoke a steady stream of papers on risk factors for asthma with investigators still trying to explain the post-second world war epidemic of allergic disease. Experimental Models continue to make important contributions to our understanding of pathogenesis of allergic disease and in the Clinical Allergy section various angles on immunotherapy are explored. New allergens continue to be described in the allergens section to make those allergen chips even more complicated. A rich and vibrant year helpfully summarized by some of our associate editors.

Risk factors and asthma phenotypes in children and adults with seasonal allergic rhinitis

BACKGROUND

There are few data on asthma risk factors and phenotypes in patients with seasonal allergic rhinitis (SAR).

METHODS

Thirty-three children (mean age, 8.27 ± 1.77 years) and 82 adults (mean age, 34.12 ± 10.59 years) with SAR were evaluated for asthma (history, reversibility of bronchial obstruction, increased inhaled nitric oxide). The following asthma risk factors were considered in the multiple regression analysis: male sex, family history of asthma, breastfeeding < 2 months, passive/active smoking, obesity, pets/molds exposure, high total serum immunoglobulin E (IgE), polysensitization (sensitized to 3 seasonal pollens with different structure), mixed sensitization (seasonal and perennial allergens), severe rhinitis (according to the Allergic Rhinitis and its Impact on Asthma guidelines), and lack of allergen-specific immunotherapy (SIT) for rhinitis preceding asthma diagnosis. Asthma phenotypes were characterized using the k-means clustering (silhouette method for cluster validation).

RESULTS

Asthma was diagnosed in 22 (66.7%) children and in 57 (69.5%) adults with SAR. Independent risk factors for asthma were lack of SIT preceding asthma diagnosis, both for children (P = 0.008132) and adults (P = 0.000017), and mixed sensitization for children (P = 0.035694). Asthma phenotypes identified in children according to the associated risk factors were: breastfeeding < 2 months and severe rhinitis in 16 (63.6%) patients; male, polysensitized, and severe rhinitis in 8 (36.4%) patients. Asthma phenotypes in adults were: polysensitization and severe rhinitis in 30 (52.6%) patients; male, exposure to pets, and severe rhinitis in 11 (19.3%) patients; and high total serum IgE and polysensitization in 16 (28.1%) patients.

CONCLUSION

Lack of SIT is an independent risk factor for asthma both in children and adults with SAR, whereas polysensitization is a risk factor only for children. The dominant asthma phenotype in children with SAR is breastfeeding < 2 months and severe rhinitis. In adults with SAR, the dominant asthma phenotype is polysensitization and severe rhinitis.

Gender-specific asthma treatment

Because genetic characteristics vary among subjects, the therapeutic effects of a certain drug differ among patients with the same disease. For this reason, special interest has focused on tailored treatments. Although it is well known that sex is genetically determined, little attention has been paid to sex differences in the clinical features and treatment of asthma. Females are more likely to suffer allergic asthma, to have difficulty controlling asthma symptoms, and to show adverse effects to drugs. As asthma symptoms show cyclic changes depending on female hormone levels in many women of child-bearing age, the use of contraceptives may specifically help to treat female patients with asthma such as those with perimenstrual asthma and severe asthma. Generally, testosterone seems to suppress asthma, and dehydroepiandrosterone (DHEA), a less virilizing androgen, may be effective for treating asthma. Evidence exists for a therapeutic and steroid-sparing effect of DHEA. However, further studies on the optimal dose and route of DHEA for each sex are needed. Monitoring of the serum DHEA-S level is necessary for patients with asthma on inhaled steroid treatment, and at minimum, replacement therapy for patients with a low level of DHEA may be helpful for treating their asthma.