Sex Differences in Asthma

Sexual dimorphism in skin immunity is mediated by an androgen-ILC2-dendritic cell axis

Males and females exhibit profound differences in immune responses and disease susceptibility. However, the factors responsible for sex differences in tissue immunity remain poorly understood. Here, we uncovered a dominant role for type 2 innate lymphoid cells (ILC2s) in shaping sexual immune dimorphism within the skin. Mechanistically, negative regulation of ILC2s by androgens leads to a reduction in dendritic cell accumulation and activation in males, along with reduced tissue immunity. Collectively, our results reveal a role for the androgen-ILC2-dendritic cell axis in controlling sexual immune dimorphism. Moreover, this work proposes that tissue immune set points are defined by the dual action of sex hormones and the microbiota, with sex hormones controlling the strength of local immunity and microbiota calibrating its tone.

Correlation between Endometriosis and Selected Allergic and Autoimmune Diseases and Eating Habits

Background and Objectives: Endometriosis is a hormone-dependent chronic inflammatory disease with serious reproductive and general health consequences. It is viewed as a multifactorial problem, consisting of matters related to altered immunity and genetics. In this study, we determined the correlation between endometriosis and allergic and autoimmune diseases in patients at reproductive age. Materials and Methods: Online surveys distributed through websites related to gynecological problems. The questionnaire was composed of 63 single and multiple-choice questions concerning the course of endometriosis, diet, and allergic and autoimmune diseases. The obtained data were assessed using statistical tests. Results: 501 female patients (mean age 31.1 SD = 6.8) were included in the study. The control group (n = 155) consisted of healthy females, whereas the study group (n = 346) consisted of female patients with endometriosis; each group was subdivided according to allergy status. There were statistically significant differences between groups for the following: positive family history of endometriosis (p = 0.0002), onset of allergic symptoms (p = 0.0003), frequency and duration of abdominal pain (p = 0.00625), and defecation disorders (p = 0.0006). Asthma was less common in the study group (p = 0.00611). The group of patients with endometriosis and allergies had a high median of consumption of red meat (p = 0.0143), fish (p = 0.0016), and dairy products (p = 0.0001). Conclusions: Endometriosis did not affect autoimmune diseases and their courses. Patients with diagnosed endometriosis presented allergy symptoms much earlier than the healthy patients. The consumption of dietary products such as soya products, red meat, and alcohol had an influence on the occurrence of endometriosis.

Associations between ambient temperature and adult asthma hospitalizations in Beijing, China: a time-stratified case-crossover study

Background

Studies on the associations between ambient temperature and asthma hospitalizations are limited, and the results are controversial. We aimed to assess the short-term effects of ambient temperature on the risk of asthma hospitalizations and quantify the hospitalization burdens of asthma attributable to non-optimal temperature in adults in Beijing, China.

Methods

We collected daily asthma hospitalizations, meteorological factors and air quality data in Beijing from 2012 to 2015. We applied a time-stratified case-crossover design and fitted a distributed lag non-linear model with a conditional quasi-Poisson regression to explore the association between ambient temperature and adult asthma hospitalizations. The effect modifications of these associations by gender and age were assessed by stratified analyses. We also computed the attributable fractions and numbers with 95% empirical confidence intervals (eCI) of asthma hospitalizations due to extreme and moderate temperatures.

Results

From 2012 to 2015, we identified a total of 18,500 hospitalizations for asthma among adult residents in Beijing, China. Compared with the optimal temperature (22 °C), the cumulative relative risk (CRR) over lag 0–30 days was 2.32 with a 95% confidence interval (CI) of 1.57–3.42 for extreme cold corresponding to the 2.5th percentile (− 6.5 °C) of temperature distribution and 2.04 (95% CI 1.52–2.74) for extreme heat corresponding to the 97.5th percentile (29 °C) of temperature distribution. 29.1% (95% eCI 17.5–38.0%) of adult asthma hospitalizations was attributable to non-optimum temperatures. Moderate cold temperatures yielded most of the burdens, with an attributable fraction of 20.3% (95% eCI 9.1–28.7%). The temperature-related risks of asthma hospitalizations were more prominent in females and younger people (19–64 years old).

Conclusions

There was a U-shaped association between ambient temperature and the risk of adult asthma hospitalizations in Beijing, China. Females and younger patients were more vulnerable to the effects of non-optimum temperatures. Most of the burden was attributable to moderate cold. Our findings may uncover the potential impact of climate changes on asthma exacerbations.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-01960-8.

Anxiety, depression, and asthma: New perspectives and approaches for psychoneuroimmunology research

The field of psychoneuroimmunology has advanced the understanding of the relationship between immunology and mental health. More work can be done to advance the field by investigating the connection between internalizing disorders and persistent airway inflammation from asthma and air pollution exposure. Asthma is a prominent airway condition that affects about 10% of developing youth and 7.7% of adults in the United States. People who develop with asthma are at three times increased risk to develop internalizing disorders, namely anxiety and depression, compared to people who do not have asthma while developing. Interestingly, sex differences also exist in asthma prevalence and internalizing disorder development that differ based on age. Exposure to air pollution also is associated with increased asthma and internalizing disorder diagnoses. New perspectives of how chronic inflammation affects the brain could provide more understanding into internalizing disorder development. This review on how asthma and air pollution cause chronic airway inflammation details recent preclinical and clinical research that begins to highlight potential mechanisms that drive comorbidity with internalizing disorder symptoms. These findings provide a foundation for future studies to identify therapies that can simultaneously treat asthma and internalizing disorders, thus potentially decreasing mental health diagnoses in asthma patients.

Gender bias in clinical trials of biological agents for severe asthma: A systematic review

Asthma is one of the most common chronic diseases characterized by sex disparities. Gender bias is a well-documented issue detected in the design of published clinical trials (CTs). International guidelines encourage researchers to analyze clinical data by sex, gender, or both where appropriate. The objective of this work was to evaluate gender bias in the published CTs of biological agents for the treatment of severe asthma. A systematic review of randomized controlled CTs of the biological agents (omalizumab, benralizumab, reslizumab, mepolizumab or dupilumab) for the treatment of severe asthma was conducted. The literature search was performed using PubMed and EMBASE without language restrictions. This study followed the corresponding international recommendations. We identified a total of 426 articles, of which 37 were finally included. Women represented 60.4% of patients included. The mean percentage of women in these trials was 59.9%, ranged from 40.8% to 76.7%. The separate analysis by sex of the main variable was only performed in 5 of the 37 publications included, and none of the trials analyzed secondary variables by sex. Only 1 of the articles discussed the results separately by sex. No study included the concept of gender in the text or analyzed the results separately by gender. The proportion of women included in CTs was higher compared to publications of other disciplines, where women were under-represented. The analysis of the main and secondary variables by sex or gender, even the discussion separately by sex, was insufficient. This gives rise to potential gender bias in these CTs.

The ALPACA study: (In)Appropriate LAMA prescribing in asthma: A cohort analysis

INTRODUCTION

Since long-acting muscarinic antagonists (LAMA) are only indicated as add-on therapy in subjects with moderate-to-severe asthma, there are concerns whether LAMA monotherapy is associated with worse asthma control.

AIM

To study the prevalence of LAMA monotherapy and its potential association with severe asthma exacerbations (SAE) in patients with asthma.

METHODS

A cohort study (2007-2017) in the IPCI primary care database, in asthma patients aged 6-50, using LAMA during follow-up. Respiratory prescriptions were retrieved from the electronic medical records based on ATC code. Asthma treatment periods were created and categorized as LAMA mono, dual (LAMA + ICS), or triple therapy (LAMA + ICS + LABA). Relative rates (RR) of SAE, adjusting for patient characteristics, were estimated to compare treatments.

RESULTS

From a total of 66,508 asthma patients, 1236 (1.9%) LAMA users were identified. Median age was 41 years, 65.9% were females. LAMA users were responsible for 3596 LAMA treatment periods of which 1390 (38.7%) were LAMA monotherapy, 553 (15.4%) dual therapy and 1653 (46.0%) triple therapy. The RR of SAE during LAMA monotherapy compared to dual therapy was 1.5 (95% CI 0.6-3.8). In patients alternating between mono and dual therapy (but never triple therapy), the RR for LAMA monotherapy increased to 5.7 (95% CI 1.4-23.6).

CONCLUSIONS

This observational study shows that when LAMA is prescribed, it is often prescribed without concurrent ICS (LAMA monotherapy). LAMA monotherapy was associated with an increased risk of exacerbations when not used concurrently with ICS. This emphasizes the importance that LAMA should never be prescribed without concomitant ICS use in patients with asthma.

Quality of life and asthma control related to hormonal transitions in women's lives

Objectives: The aim was to investigate if menstruation and use of exogenous sex hormones influence self-reported asthma related quality of life (QoL) and asthma control.Methods: The study is based on two asthma cohorts randomly selected in primary and secondary care. A total of 622 female patients 18-65 years were included and classified as premenopausal ≤46 years (n = 338) and peri/postmenopausal 47-65 years (n = 284). Questionnaire data from 2012 and 2014 with demographics, asthma related issues and sex hormone status. Outcome measures were Mini Asthma Quality of Life Questionnaire (Mini-AQLQ) and asthma control including Asthma Control Test (ACT) and exacerbations last six months.Results: Premenopausal women with menstruation related asthma worsening, perimenstrual asthma (PMA) (9%), had a clinically relevant lower Mini-AQLQ mean score 4.9 vs. 5.8 (p < 0.001), lower asthma control with ACT score <20, 72% vs. 28% (p < 0.001) and higher exacerbation frequency 44% vs. 20% (p = 0.004) compared with women without PMA. Women with irregular menstruation had higher exacerbation frequency than women with regular menstruation (p = 0.023). Hormonal contraceptives had no impact on QoL and asthma control. Peri/postmenopausal women with menopausal hormone therapy (MHT) had a clinically relevant lower Mini-AQLQ mean score compared to those without MHT, 4.9 vs 5.4 (p < 0.001), but no differences in asthma control.Conclusion: Women with PMA had lower QoL and more uncontrolled asthma than women without PMA. Peri/postmenopausal women with MHT had lower QoL than women without MHT. Individual clinical management of women with asthma may benefit from information about their sex hormone status.

Depression Levels Influence the Rate of Asthma Exacerbations in Females

Background: Anxiety and depression are common psychological disturbances among asthmatic patients. The aim of the present study is the assessment of anxiety and depression in asthmatic patients and their correlation with symptoms control level and number of exacerbations per year. Methods: One hundred patients with asthma diagnosis, according to the Global Initiative for Asthma (GINA), aged > 18 years old, having a stable disease, were included. Emotional status was evaluated using the Hospital Anxiety Depression Scale (HADS). Patients were followed up for a year to assess the number and severity of exacerbations. Results: Most of our patients were female (58%), middle-aged (mean = 54 ± 13), and married (81%), with low frequency of smoking habits (smokers, ex-smokers and non-smokers were 26%, 30% and 37%, respectively) and low levels of both anxiety and depression [median (interquartile range (IQR)) = 4(2) and median (IQR) = 4(2), respectively]. At the low and moderate level of the depression subscale, female patients experienced asthma exacerbations more frequently compared to male patients (adjusted Incidence Rate Ratio (aIRR) = 4.30; 95% Confidence Interval (CI): 1.94–9.53 and aIRR = 1.82; 95% CI: 1.07–3.13, respectively). Conclusions. Clinicians should evaluate asthma patients for depression, as gender differentially influences outcomes among those with low and moderate levels of depression, with female asthmatics presenting more frequent exacerbations.

Prevalence of overuse of short-acting beta-2 agonists (SABA) and associated factors among patients with asthma in Germany

BACKGROUND

Overuse of short-acting beta-2 agonists (SABA), which do not treat the underlying inflammation of asthma, is linked to poor clinical outcomes such as increased exacerbation risk. This study, as part of the SABINA program, estimated the prevalence of SABA overuse and associated variables in outpatients in Germany.

METHODS

This retrospective study used anonymized electronic healthcare data from the Disease Analyzer database (IQVIA). A total of 15,640 patients aged ≥ 12 years with asthma who received ≥ 1 SABA prescription(s) between July 2017 and June 2018 in 924 general physician and 22 pneumologist (PN) practices were included. SABA overuse was defined as ≥ 3 prescribed inhalers (~ 200 puffs each) during the study period. The associations between SABA overuse and physician specialty, Global Initiative for Asthma (GINA) steps (based on asthma medications), age, sex, and inhaled corticosteroid (ICS)/long-acting beta agonist (LABA) use were estimated using multivariable regression for patients with probable moderate (GINA step 2) and probable severe (GINA steps 3-5) asthma.

RESULTS

Annually, 36% of all patients (GINA steps 1-5) in general and 38% in PN practices received ≥ 3 SABA inhalers. The risk of SABA overuse was 14% higher in patients treated by a general practitioner vs. a PN; 34% and 85% higher in GINA steps 4 and 5, respectively, vs. GINA step 3; and 40% higher in male vs. female patients.

CONCLUSIONS

SABA overuse is prevalent among patients with asthma across all GINA steps in Germany, which may indicate suboptimal asthma control. Further studies are needed to investigate the reasons behind SABA overuse.

Electronic cigarette (e-cigarette) use and frequency of asthma symptoms in adult asthmatics in California

INTRODUCTION

Electronic cigarettes use is increasing in the United States. One motive for e-cigarette's popularity is that they wean from combustible cigarettes. Smokers perceive electronic cigarette products as healthier than cigarette smoking and as a useful tool for smoking cessation. However, research has indicated the use of electronic cigarettes may have harmful effects on respiratory function even with short-term use. Respiratory effects of e-cigarette use among asthmatics are little understood.

OBJECTIVE

The aim of this study was to determine the association between e-cigarette use and frequency of asthma symptoms among adult asthmatics in California from 2015-2016.

METHODS

This cross-sectional study included a total of 1277 adult asthmatics. The presence of asthma was based on an adult's self-reported doctor diagnosis. The analysis was controlled for age, education, sex, race, body mass index, and smoking status.

RESULTS

E-cigarette use was associated with increased odds of having more frequent asthma symptoms (OR = 1.69, CI: 1.20-2.39, p = 0.002; OR_adj = 1.65, CI: 1.09-2.49, p = 0.016). Male e-cigarette users were more likely to have more frequent asthma symptoms compared to male nonusers (OR = 1.90, CI: 1.13-3.19, p = 0.015; OR_adj = 2.42, CI: 1.28-4.55, p = 0.006). No differences were found between female e-cigarette users and nonusers (OR = 1.43, CI: 0.86-2.37, p = 0.162; OR_adj = 1.26, CI: 0.72-2.18, p = 0.162).

CONCLUSION

Our findings suggest that e-cigarette use is associated with more frequent asthma symptoms and disproportionally affects male asthmatics.

Differences in diagnostic patterns of obstructive airway disease between areas and sex in Sweden and Finland - the Nordic EpiLung study

OBJECTIVE

To investigate the current prevalence of physician-diagnosed obstructive airway diseases by respiratory symptoms and by sex in Sweden and Finland.

METHOD

In 2016, a postal questionnaire was answered by 34,072 randomly selected adults in four study areas: Västra Götaland and Norrbotten in Sweden, and Seinäjoki-Vaasa and Helsinki in Finland.

RESULTS

The prevalence of asthma symptoms was higher in Norrbotten (13.2%), Seinäjoki-Vaasa (14.8%) and Helsinki (14.4%) than in Västra Götaland (10.7%), and physician-diagnosed asthma was highest in Norrbotten (13.0%) and least in Västra Götaland (10.1%). Chronic productive cough was most common in the Finnish areas (7.7-8.2% versus 6.3-6.7%) while the prevalence of physician-diagnosed chronic bronchitis (CB) or chronic obstructive pulmonary disease (COPD) varied between 1.7 and 2.7% in the four areas. Among individuals with respiratory symptoms, the prevalence of asthma was most common in Norrbotten, while a diagnosis of COPD or CB was most common in Västra Götaland and Seinäjoki-Vaasa. More women than men with respiratory symptoms reported a diagnosis of asthma in Sweden and Seinäjoki-Vaasa but there were no sex differences in Helsinki. In Sweden, more women than men with symptoms of cough or phlegm reported a diagnosis of CB or COPD, while in Finland the opposite was found.

CONCLUSION

The prevalence of respiratory symptoms and corresponding diagnoses varied between and within the countries. The proportion reporting a diagnosis of obstructive airway disease among individuals with respiratory symptoms varied, indicating differences in diagnostic patterns both between areas and by sex.

Associations between prenatal exposure to DDT and DDE and allergy symptoms and diagnoses in the Venda Health Examination of Mothers, Babies and their Environment (VHEMBE), South Africa

Dichlorodiphenyl trichloroethane (DDT) is an organochlorine insecticide that is banned internationally except for use as part of Indoor Residual Spraying (IRS) programs to control malaria. Although animal studies show that DDT and its breakdown product dichlorodiphenyl dichloroethylene (DDE) affect the immune system and may cause allergies, no studies have examined this question in populations where IRS is conducted. The aim of our study was to investigate whether prenatal exposure to DDT and DDE is associated with allergy symptoms and diagnose among South African children living in an area where IRS is conducted. To accomplish this aim, we used data from the Venda Health Examination of Mothers, Babies and their Environment (VHEMBE), an ongoing birth cohort study of 752 children born between 2012 and 2013 in the rural Vhembe district of Limpopo, South Africa. We measured maternal peripartum serum concentrations of DDT and DDE, and administered a questionnaire to the caregivers of 658 children aged 3.5 years to collect information on allergy symptoms and diagnoses as well as potential confounders using validated instruments. Using multiple logistic regression models, we found positive associations between DDT and DDE serum concentrations and most of the allergy symptoms and diagnoses. Maternal DDT (Odds Ratio [OR] = 1.5 per 10-fold increase, 95% Confidence interval, CI = 1.0, 2.3) and DDE (OR = 1.4, 95% CI = 0.8, 2.4) serum concentrations were most strongly associated with caregiver report of wheezing or whistling in the chest. Concentrations of DDT and/or DDE were also associated with increased odds of children's chests sounding wheezy during or after exercise, itchy rashes coming and going for at least six months, diagnosis of food allergy, and diagnosis of dust or dust mites allergy but confidence intervals crossed the null. Results suggest that prenatal exposure to DDT, and possibly DDE, is associated with elevated odds of wheezing among children from an IRS area.

Impacts of exposure to humidex on the risk of childhood asthma hospitalizations in Hefei, China: Effect modification by gender and age

BACKGROUND

With global climate change, there is growing concern about the effects of temperature changes on childhood asthma. However, current research only focuses on the effects of temperature, while ignoring the adverse effects of humidity on children.

OBJECTIVES

Our study aimed to quantify the impact of humidex on childhood asthma hospitalizations, which combined temperature and humidity, and further to assess how the effect is modified by individual-factors, such as age and gender.

METHODS

Poisson generalized linear models combined with distributed lag nonlinear models were used to estimate the association between daily childhood asthma hospitalizations and humidex from 2013 to 2016. Air pollutions (CO, O_3, and NO₂) and wind velocity were modelled simultaneously using DLNM, as well as day of week, seasonality and long-term trend.

RESULTS

Low humidex was associated with an increased risk of admissions for asthma in children. The adverse effect appeared on the 4th day, with the RR of 1.045 (95%CI: 1.007-1.084) and lasted until the 7th day (RR: 1.045, 95%CI: 1.006-1.085). Compared with the male, there was an immediate effect on female exposed to low humidex. And the female seems to be more sensitive to low humidex. Besides, the significant effects of humidex on children asthma were detected in the children with preschool and school-age, whereas not for the subgroup of infants. And the school-age children are most sensitive to low humidex.

CONCLUSIONS

Low humidex was associated with the increased risk of admissions for childhood asthma in Hefei. Children suffering from asthma should avoid exposure to the low humidex environment, especially in female and school-age children. In addition, the index of humidex was more significant for disease prevention and public health than the average temperature. These findings may provide epidemiology evidence for formulating precaution guidelines to reduce the risk of childhood asthma hospitalizations.

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.

Is there a sex-shift in prevalence of allergic rhinitis and comorbid asthma from childhood to adulthood? A meta-analysis

Background

Allergic rhinitis and asthma as single entities affect more boys than girls in childhood but more females in adulthood. However, it is unclear if this prevalence sex-shift also occurs in allergic rhinitis and concurrent asthma. Thus, our aim was to compare sex-specific differences in the prevalence of coexisting allergic rhinitis and asthma in childhood, adolescence and adulthood.

Methods

Post-hoc analysis of systematic review with meta-analysis concerning sex-specific prevalence of allergic rhinitis. Using random-effects meta-analysis, we assessed male–female ratios for coexisting allergic rhinitis and asthma in children (0–10 years), adolescents (11–17) and adults (> 17). Electronic searches were performed using MEDLINE and EMBASE for the time period 2000–2014. We included population-based observational studies, reporting coexisting allergic rhinitis and asthma as outcome stratified by sex. We excluded non-original or non-population-based studies, studies with only male or female participants or selective patient collectives.

Results

From a total of 6539 citations, 10 studies with a total of 93,483 participants met the inclusion criteria. The male–female ratios (95% CI) for coexisting allergic rhinitis and asthma were 1.65 (1.52; 1.78) in children (N = 6 studies), 0.61 (0.51; 0.72) in adolescents (N = 2) and 1.03 (0.79; 1.35) in adults (N = 2). Male–female ratios for allergic rhinitis only were 1.25 (1.19; 1.32, N = 5) in children, 0.80 (0.71; 0.89, N = 2) in adolescents and 0.98 (0.74; 1.30, N = 2) in adults, respectively.

Conclusions

The prevalence of coexisting allergic rhinitis and asthma shows a clear male predominance in childhood and seems to switch to a female predominance in adolescents. This switch was less pronounced for allergic rhinitis only.

Electronic supplementary material

The online version of this article (10.1186/s13601-017-0176-5) contains supplementary material, which is available to authorized users.

Sex differences in outcomes after discharge from Alberta emergency departments for asthma: A large population-based study

OBJECTIVE

Asthma exacerbations frequently result in emergency department (ED) visits. While sex differences have been identified in some asthma studies, there is a paucity of literature on sex differences in the ED setting, especially population-based ones. This study examines sex differences in important outcomes of patients discharged from EDs for acute asthma in Alberta, Canada.

METHODS

Alberta residents aged from 2 to 55 years discharged from EDs with a primary diagnosis of asthma during 1999-2011 were identified from administrative databases from a single-payer health care system for the entire geographic region of Alberta. Multivariable Cox regression models analyzed time to first follow-up physician or specialist visit, and logistic regression models analyzed the binary outcome of ED return within 30 days for asthma.

RESULTS

There were 115,853 discharged patients analyzed (40.4% and 59.1% female in pediatric and adult groups, respectively). Approximately 26% of patients revisited the ED during 1999-2011 and 5.1% did so within 30 days. Women had higher odds of a 30-day ED return after ED discharge than men (unadjusted odds ratio [uOR] = 1.26; 95% confidence interval [CI] 1.17-1.36). Time to first non-ED physician follow-up was shorter for girls (unadjusted hazard ratio [uHR] = 1.05; 95%CI 1.03-1.07) and women (uHR = 1.62; 95%CI 1.59-1.64) than for boys and men, respectively. Significant interactions between sex and age, socio-economic status, area of residence, and comorbidities were identified and changed the effect of sex on outcomes.

CONCLUSIONS

In conclusion, women return to EDs within 30 days of discharge for acute asthma more often than men. Time to first non-ED physician follow-up for children and adults differed by sex. Multiple factors likely contribute to these differences; however, identifying these differences is critical to understand the influence of sex on health behaviors and outcomes.

Fragrances and work-related asthma-California surveillance data, 1993-2012

OBJECTIVE

Fragrance chemicals are used in a large array of products. Workers may be exposed to these chemicals in the workplace directly when used as air fresheners, or indirectly in personal care products used by coworkers or others. This study characterizes work-related asthma (WRA) cases associated with fragrance exposures in California workplaces from 1993 through 2012.

METHODS

We used the California Work-Related Asthma Prevention Program's surveillance database to identify individuals with physician-diagnosed WRA associated with the use of air fresheners and scented personal care products (perfumes, colognes, etc.). Cases were classified using previously published, standardized surveillance methods.

RESULTS

Perfume was the ninth most common exposure identified from 1993 through 2012. A total of 270 WRA cases associated with fragrance exposure were reported during this period, representing 3.8% of all confirmed cases. These 270 cases included 242 associated with perfume or cologne, 32 associated with air freshener, and 4 associated with both. Similar to non-fragrance cases, nearly a quarter of fragrance-associated cases were classified as new-onset asthma. Fragrance-associated cases were significantly more likely to be in office, health, and education jobs than non-fragrance-associated cases. When compared to non-fragrance cases, fragrance cases were significantly more likely to be female (94% vs 62%) and be classified as having work-aggravated asthma (38% vs 20%), yet had similar outcomes compared with cases associated with other exposures.

CONCLUSIONS

Our surveillance data show that fragrance use in the workplace is associated with WRA. Prevention methods include employee education, enforced fragrance-free policies, well-designed ventilation systems, and good building maintenance.

Peri-adolescent asthma symptoms cause adult anxiety-related behavior and neurobiological processes in mice

Human and animal studies have shown that physical challenges and stressors during adolescence can have significant influences on behavioral and neurobiological development associated with internalizing disorders such as anxiety and depression. Given the prevalence of asthma during adolescence and increased rates of internalizing disorders in humans with asthma, we used a mouse model to test if and which symptoms of adolescent allergic asthma (airway inflammation or labored breathing) cause adult anxiety- and depression-related behavior and brain function. To mimic symptoms of allergic asthma in young BALB/cJ mice (postnatal days [P] 7-57; N=98), we induced lung inflammation with repeated intranasal administration of house dust mite extract (most common aeroallergen for humans) and bronchoconstriction with aerosolized methacholine (non-selective muscarinic receptor agonist). Three experimental groups, in addition to a control group, included: (1) "Airway inflammation only", allergen exposure 3 times/week, (2) "Labored breathing only", methacholine exposure once/week, and (3) "Airway inflammation+Labored breathing", allergen and methacholine exposure. Compared to controls, mice that experienced methacholine-induced labored breathing during adolescence displayed a ∼20% decrease in time on open arms of the elevated plus maze in early adulthood (P60), a ∼30% decrease in brainstem serotonin transporter (SERT) mRNA expression and a ∼50% increase in hippocampal serotonin receptor 1a (5Htr1a) and corticotropin releasing hormone receptor 1 (Crhr1) expression in adulthood (P75). This is the first evidence that experimentally-induced clinical symptoms of adolescent asthma alter adult anxiety-related behavior and brain function several weeks after completion of asthma manipulations.

Fatal asthma; is it still an epidemic?

BACKGROUND

Asthma mortality has declined since the 1980s. Nevertheless the World Health Organization (WHO) identified asthma as responsible for 225.000 deaths worldwide in 2005, and 430.000 fatal cases are expected by 2030. Some unexpected and concentrated fatal asthma events all occurred between 2013 and 2015 in Veneto, a North Eastern region of Italy, which prompted a more in-depth investigation of characteristics and risk factors.

METHODS

A web search including key words related to fatal asthma in Italy between 2013 and 2015 has been performed. Concerning the cases that occurred in Veneto, subjects' clinical records have been evaluated and details about concomitant weather conditions, pollutants and pollen count have been collected.

RESULTS

Twenty-three cases of asthma deaths were found in Italy; 16 of them (69%) occurred in the Veneto Region. A prevalence of male and young age was observed. Most of patients were atopic, died in the night-time hours and during the weekends. The possible risk factors identified were the sensitization to alternaria, previous near fatal asthma attacks and the incorrect treatment of the disease. Weather condition did not appear to be related to the fatal exacerbations, whereas among the pollutants only ozone was detected over the accepted limits. Smoking habits, possible drug abuse and concomitant complementary therapies might be regarded as further risk factors.

DISCUSSION

Although not free from potential biases, our web search and further investigations highlight an increasing asthma mortality trend, similarly to what other observatories report. The analysis of available clinical data suggests that the lack of treatment more than a severe asthma phenotype characterizes the fatal events.

CONCLUSIONS

Asthma mortality still represents a critical issue in the management of the disease, particularly in youngsters. Once more the inadequate treatment and the lack of adherence seem to be not only related to the uncontrolled asthma but also to asthma mortality.

In utero exposure to 25-hydroxyvitamin D and risk of childhood asthma, wheeze, and respiratory tract infections: A meta-analysis of birth cohort studies

BACKGROUND

Studies of the associations between in utero 25-hydroxyvitamin D (25[OH]D) exposure and risk of childhood asthma, wheeze, and respiratory tract infections are inconsistent and inconclusive.

OBJECTIVES

We sought to assess associations between 25(OH)D levels in cord blood or maternal venous blood and risk of offspring's asthma, wheeze, and respiratory tract infections.

METHODS

Data were derived from PubMed, Embase, Google Scholar, references from relevant articles, and de novo results from published studies until December 2015. A random-effects meta-analysis was conducted among 16 birth cohort studies.

RESULTS

Comparing the highest with the lowest category of 25(OH)D levels, the pooled odds ratios were 0.84 (95% CI, 0.70-1.01; P = .064) for asthma, 0.77 (95% CI, 0.58-1.03; P = .083) for wheeze, and 0.85 (95% CI, 0.66-1.09; P = .187) for respiratory tract infections. The observed inverse association for wheeze was more pronounced and became statistically significant in the studies that measured 25(OH)D levels in cord blood (0.43; 95% CI, 0.29-0.62; P < .001).

CONCLUSIONS

Accumulated evidence generated from this meta-analysis suggests that increased in utero exposure to 25(OH)D is inversely associated with the risk of asthma and wheeze during childhood. These findings are in keeping with the results of 2 recently published randomized clinical trials of vitamin D supplementation during pregnancy.

Sex differences in asthma and gastroesophageal reflux disease incidence among the World Trade Center Health Program General Responder Cohort

BACKGROUND

Asthma and gastroesophageal reflux disease (GERD) are two common conditions among the responders to the WTC attacks. This study examined whether the cumulative incidence rates of asthma and GERD differed by sex among 24,022 and 23,557 WTC responders, respectively.

METHODS

Cox proportional hazards regression was used to examine the sex difference in the rate of onset of physician-diagnosed asthma or GERD, from 9/12/2001 through 12/31/2015.

RESULTS

The cumulative incidence of asthma reached 23% for women and 17% for men by the end of 2015, and the cumulative incidence of GERD reached 45% for women and 38% for men. Comparing women to men, the hazard ratio was 1.48 (95% confidence interval (CI): 1.27, 1.74) for asthma, and 1.25 (95% CI: 1.13, 1.38) for GERD.

CONCLUSIONS

WTC general responders have a substantial burden of asthma and GERD, with higher incidence in women. Am. J. Ind. Med. 59:815-822, 2016. © 2016 Wiley Periodicals, Inc.

Local genotype influences DNA methylation at two asthma-associated regions, 5q31 and 17q21, in a founder effect population

BACKGROUND

Two asthma-associated regions 17q12-q21 and 5q31.1 harbour genes that show strong effect of genotype on expression levels. DNA methylation has an important role in gene regulation; therefore, we examined DNA methylation at promoters of 12 genes from 5q31 and 17q12-q21 regions. Our goal was to determine whether DNA methylation was associated with predisposition to asthma and whether such a relationship was independent from genetic association.

METHODS

Using sodium bisulfite sequencing and pyrosequencing methylation assays, we examined the effect of genotype on DNA methylation in peripheral blood cells from individuals from the Saguenay-Lac-Saint-Jean asthma familial collection and lymphoblastoid cell lines.

RESULTS

The local genotype influenced methylation levels of solute carrier family 22 (organic 3 cation/carnitine transporter) member 5 (SLC22A5), zona pellucida binding protein 2 (ZPBP2) and gasdermin A (GSDMA) promoter regions. The genotype had a dominant effect on ZPBP2 and GSDMA methylation with lower methylation levels in individuals that carry the asthma-predisposing alleles. Males also had lower methylation at the ZPBP2 promoter than females. We did not observe an effect of asthma status that would be independent of the genotype and the sex effects in the GSDMA, ZPBP2 and SLC22A5 regions; however, GSDMA and ZPBP2 data were suggestive of interaction between asthma and methylation levels in females and SLC22A5 in males.

CONCLUSIONS

The local genotype influences methylation levels at SLC22A5 and ZPBP2 promoters independently of the asthma status. Further studies are necessary to confirm the relationship between GSDMA-ZPBP2 and SLC22A5 methylation and asthma in females and males separately.

Natural progression of childhood asthma symptoms and strong influence of sex and puberty

RATIONALE

Asthma prevalence, onset, remission and relapse, and healthcare use have been intensively studied. However, asthma symptom progression through childhood and adolescence has not been well studied, in part due to the challenges in obtaining consistent and robust long-term follow-up data on a large series of subjects with asthma.

OBJECTIVES

To use the asthma diary symptom data of the Childhood Asthma Management Program placebo group (5 yr, 418 subjects, and total 564,518 records) to establish sex-specific high-resolution time courses of the natural progression of asthma symptoms through childhood and adolescence.

METHODS

We used the asthma diary symptom code as a measure of daily disease severity. Annual records of Tanner stage were used to determine the influence of puberty on severity. A data alignment technique was used to derive 13-year time courses of mean symptoms and mean Tanner stage.

MEASUREMENTS AND MAIN RESULTS

Data analyses showed three age- and sex-related phases of asthma symptom progression: Phase 1 (ages 5 and 6 yr)-greater severity in boys; Phase 2 (ages 7 to 9 yr)-no sex difference in severity; and Phase 3 (age 10-17 yr)-greater severity in girls. The continuous decline of symptoms in both sexes stops abruptly at the onset of puberty.

CONCLUSIONS

The severity of asthma symptoms varies through childhood and adolescence, and patterns differ by sex. Puberty has a strong influence on symptom progression in both sexes. Progression of symptoms is a distinct aspect of asthma epidemiology.

Gender differences in work-related asthma: surveillance data from California, Massachusetts, Michigan, and New Jersey, 1993-2008

OBJECTIVE

To characterize work-related asthma by gender.

METHODS

We analyzed state-based sentinel surveillance data on confirmed work-related asthma cases collected from California, Massachusetts, Michigan, and New Jersey during 1993-2008. We used Chi-square and Fisher's Exact Test statistics to compare select characteristics between females and males.

RESULTS

Of the 8239 confirmed work-related asthma cases, 60% were female. When compared to males with work-related asthma, females with work-related asthma were more likely to be identified through workers' compensation (14.8% versus 10.6%) and less likely to be identified through hospital data (14.2% versus 16.9%). Moreover, when compared to males, females were more likely to have work-aggravated asthma (24.4% versus 13.5%) and less likely to have new-onset asthma (48.0% versus 56.5%). Females were also more likely than males with work-related asthma to work in healthcare and social assistance (28.7% versus 5.2%), educational services (11.8% versus 4.2%), and retail trade (5.0% versus 3.9%) industries and in office and administrative support (20.0% versus 4.0%), healthcare practitioners and technical (13.4% versus 1.6%), and education training and library (6.2% versus 1.3%) occupations. Agent groups most frequently associated with work-related asthma were miscellaneous chemicals (20.3%), cleaning materials (15.3%), and indoor air pollutants (14.9%) in females and miscellaneous chemicals (15.7%), mineral and inorganic dusts (13.2%), and pyrolysis products (12.7%) in males.

CONCLUSIONS

Among adults with work-related asthma, males and females differ in terms of workplace exposures, occupations, and industries. Physicians should consider these gender differences when diagnosing and treating asthma in working adults.

Sex- and age-dependent DNA methylation at the 17q12-q21 locus associated with childhood asthma

Chromosomal region 17q12-q21 is one of the best-replicated genome-wide association study (GWAS) hits and associated with childhood-onset asthma. However, the mechanism by which the genetic association is restricted to childhood-onset disease is unclear. During childhood, more boys than girls develop asthma. Therefore, we tested the hypothesis that the 17q12-q21 genetic association was sex-specific. Indeed, a TDT test showed that in the Saguenay-Lac-Saint-Jean familial collection, the 17q12-q21 association was significant among male, but not among female asthmatic subjects. We next hypothesized that the bias in the genetic association resulted from sex-specific and/or age-dependent DNA methylation at regulatory regions and determined the methylation profiles of five 17q12-q21 gene promoters using the bisulfite sequencing methylation assay. We identified a single regulatory region within the zona pellucida binding protein 2 (ZPBP2) gene, which showed statistically significant differences between males and females with respect to DNA methylation. DNA methylation also varied with age and was higher in adult males compared to boys. We have recently identified two functionally important polymorphisms, both within the ZPBP2 gene that influence expression levels of neighboring genes. Combined with the results of the present work, these data converge pointing to the same 5 kb region within the ZPBP2 gene as a critical region for both gene expression regulation and predisposition to asthma. Our data show that sex- and age-dependent DNA methylation may act as a modifier of genetic effects and influence the results of genetic association studies.

Factors related with the higher percentage of hospitalizations due to asthma amongst women: the FRIAM study

INTRODUCTION

The reason why there is a higher hospitalization rate due to asthma exacerbations amongst women is unclear. The objective of this study is to explore the possible causes that may explain this fact.

METHODS

A multi-center, prospective study including asthma patients hospitalized in the pulmonary medicine departments during a two-year period. By means of a questionnaire, the following data were collected: demographic characteristics and treatment compliance, anxiety-depression, hyperventilation and asthma control, both prior to and during the hospitalization.

RESULTS

183 patients were included, 115 (62.84%) of whom were women. The women were older (52.4 ± 18.3/43.4 ± 18.7; P=.02), were more frequently prescribed inhaled corticosteroids (63.2%/47.1%; P=.03) and had a higher rate of hyperventilation syndrome (57.3/35.9; P=.02) and a longer mean hospital stay (7.3 ± 3.4/5.9 ± 3.6; P=.02). The percentage of smokers among the women was lower (21.2%/38.8%; p=0.01) and the FEV(1) was lower at admittance (58.2% ± 15.9/67.5% ± 17.4; P=.03). In the 40 to 60-year-old age range, an association was demonstrated between being female and the 'previous hospitalizations' variable (OR, 16.1; 95% CI, 1.6-156.7); sex and obesity were also independently associated (OR, 4.8; 95% CI, 1.06-22).

CONCLUSIONS

In this cohort, the rate of hospitalization for asthma was higher in women than in men. Being a woman between the ages of 40 and 60 is associated with previous hospitalizations and is a risk factor for asthma-related hospitalization. This situation could partially be explained by the hormonal changes during menopause, where polyposis and obesity are independent risk factors.

Estrogen stimulates Th2 cytokine production and regulates the compartmentalisation of eosinophils during allergen challenge in a mouse model of asthma

BACKGROUND

The observation that asthma becomes more prevalent following puberty in females suggests estrogen potentiates the development of this disease. However, most studies examining the role of estrogen in rodent models of asthma are complicated by their reliance on ovariectomised mice in which hormones other than estrogen are also attenuated.

METHODS

We aimed to understand the influence of estrogen on allergic airway disease by using type I (tamoxifen) or type II (ICI 182,780) antagonists in female mice or delivering estradiol to male mice during aeroallergen challenge.

RESULTS

The antagonists showed that estrogen promoted both the mobilisation of bone marrow eosinophils and egression of eosinophils to the airway lumen. These findings were corroborated in male mice treated with estradiol, which increased eosinophil numbers in both blood and airways. Estrogen stimulated goblet cell hyperplasia and baseline lung resistance, but had little effect on the number of eosinophils in the bronchial submucosa or methacholine-induced airway hyperreactivity. Estrogen receptor α was expressed by CD4+ T cells from allergic mice, and estrogen promoted the production of IL-5 and IL-13, and suppressed the production of the eicosanoid 12-HETE by mediastinal lymph node cells.

CONCLUSIONS

These data show that during aeroallergen challenge, estrogen stimulates Th2 cytokine production, which may be linked to its ability to suppress 12-HETE. Lung resistance at baseline, goblet cell hyperplasia and the compartmentalisation of eosinophils was also influenced by estrogen. However, estrogen does not play a major role in stimulating enhanced sensitivity to methacholine-induced lung resistance.

Sensory functions of motile cilia and implication for bronchiectasis

Cilia are specialized organelles that extend from the cell surface into the local environment. Cilia of the airway epithelia are motile to provide mucociliary clearance. On other cells, solitary cilia are specialized to detect chemical or mechanosensory signals. Sensory proteins in motile cilia have recently been identified that detect fluid flow, bitter taste and sex hormones. The relationship of these sensory functions in motile cilia to disease is now being revealed. An example are the polycystin-1 and polycystin-2 proteins that function as a flow sensor in kidney cilia and are mutated in autosomal dominant polycystic kidney disease (ADPKD). These polycystins are also expressed in motile cilia, potentially operating as sensors in the lung. Computed tomography studies from patients with ADPKD reveal evidence of bronchiectasis, suggesting polycystins are important in lung function. The motile cilia expression of this protein complex, as well as sensory channel TRPV4, bitter taste and sex hormones receptors, indicate that the cilia is wired to interpret environmental cues. Defective signaling of sensory proteins may result in a ciliopathy that includes lung disease.

Sex steroid receptors in human lung diseases

Several epidemiological studies have reported that gender differences exist in clinical and biological manifestations of human lung diseases. In particular, women are far more likely to develop both neoplastic and non-neoplastic lung diseases than men. This gender difference above suggests that sex steroid may be involved in the pathogenesis of various lung diseases. These sex steroids mediate their effects through sex steroid receptors including estrogen receptors (ER) i.e. ERα and ERβ progesterone receptors (PR) i.e. PR-A and PR-B and androgen receptors (ARs), all of which have been reported to be expressed in lung tissue. Therefore it becomes important to clarify the potential roles of sex steroid receptor in both neoplastic and non-neoplastic lung diseases toward improved treatment options for the patients. In this review, we summarized a number of studies in humans and experimental animals that have identified possible roles of sex steroids in respiratory physiology and pathology.

The impact of socioeconomic factors on asthma hospitalization rates by rural classification

Asthma hospitalization rates have increased in the past decade. Research has shown that there are multiple correlates for this increase but that driving causal factors may differ for asthma hospitalization rates in rural and non-rural settings. Here we examine the socioeconomic correlates to asthma hospitalization rates in Maine for both rural and non-rural populations to examine the similarity and differences in causal factors. Findings indicate a clear SES gradient relative to asthma hospitalization rates; as population measured SES decreased, asthma hospitalization rates increased. The associated causal factors were found to differ in rural and non-rural areas. In non-rural areas, the presence of insurance was associated with increases in the asthma hospitalization rates while in rural areas, income, occupation and the percentage of non-English language speaking persons were associated with lower asthma hospitalization rates. Public policy should focus on targeted prevention strategies at the community level, especially in rural areas where cultural competency and socioeconomic factors are increasingly important.

Asthma and chronic obstructive pulmonary disease: common genes, common environments?

Asthma and chronic obstructive pulmonary disease (COPD) show similarities and substantial differences. The Dutch hypothesis stipulated that asthma and COPD have common genetic and environmental risk factors (allergens, infections, smoking), which ultimately lead to clinical disease depending on the timing and type of environmental exposures (Postma and Boezen, Chest 2004;126:96S-104S). Thus, a particular group of shared genetic factors may lead to asthma when combined with specific environmental factors that are met at a certain stage in life, whereas combination with other environmental factors, or similar environmental factors at a different stage in life, will lead toward COPD. Multiple genes have been found for asthma and COPD. In addition to genes unique to these diseases, some shared genetic risk factors exist. Moreover, there are both common host risk factors and environmental risk factors for asthma and COPD. Here we put forward, based on the data available, that genes that affect lung development in utero and lung growth in early childhood in interaction with environmental detrimental stimuli, such as smoking and air pollution, are contributing to asthma in childhood and the ultimate development of COPD. Additional genes and environmental factors then drive specific immunological mechanisms underlying asthma, and others may contribute to the ultimate development of specific subtypes of COPD (i.e., airway disease with mucous hypersecretion, small airway disease, and emphysema). The genetic predisposition to the derailment of certain pathways may further help to define subgroups of asthma and COPD. In the end this may lead to stratification of patients by their genetic make-up and open new therapeutic prospects.

The impact of sex, gender and pregnancy on 2009 H1N1 disease

Children and young adults of reproductive age have emerged as groups that are highly vulnerable to the current 2009 H1N1 pandemic. The sex of an individual is a fundamental factor that can influence exposure, susceptibility and immune responses to influenza. Worldwide, the incidence, disease burden, morbidity and mortality rates following exposure to the 2009 H1N1 influenza virus differ between males and females and are often age-dependent. Pregnancy and differences in the presentation of various risk factors contribute to the worse outcome of infection in women. Vaccination and antiviral treatment efficacy also vary in a sex-dependent manner. Finally, sex-specific genetic and hormonal differences may contribute to the severity of influenza and the clearance of viral infection. The contribution of sex and gender to influenza can only be determined by a greater consideration of these factors in clinical and epidemiological studies and increased research into the biological basis underlying these differences.

Hormonal influences on lung function and response to environmental agents: lessons from animal models of respiratory disease

Numerous studies in humans and experimental animals have identified considerable sex differences in respiratory physiology and in the response of the lung to environmental agents. These differences appear to be mediated, at least in part, by sex hormones and their nuclear receptors. Moreover, animal models are increasingly used to study pathogenic mechanisms and test potential therapies for a variety of human lung diseases, many of which appear to be influenced by sex and sex hormones. In this article, data are summarized from studies of lung function and disease in which sex differences have been observed. Specific attention is paid to animal models of acute lung injury, nonallergic and allergic lung inflammation, and lung fibrosis. It is anticipated that continued investigation of the role of sex and sex hormones in animal models will provide valuable insight into the pathogenesis and potential treatments for a variety of acute and chronic human lung diseases.

Chronic obstructive pulmonary disease and altered risk of lung cancer in a population-based case-control study

BACKGROUND

Chronic obstructive pulmonary disease (COPD) has been consistently associated with increased risk of lung cancer. However, previous studies have had limited ability to determine whether the association is due to smoking.

METHODOLOGY/PRINCIPAL FINDINGS

The Environment And Genetics in Lung cancer Etiology (EAGLE) population-based case-control study recruited 2100 cases and 2120 controls, of whom 1934 cases and 2108 controls reported about diagnosis of chronic bronchitis, emphysema, COPD (chronic bronchitis and/or emphysema), or asthma more than 1 year before enrollment. We estimated odds ratios (OR) and 95% confidence intervals (CI) using logistic regression. After adjustment for smoking, other previous lung diseases, and study design variables, lung cancer risk was elevated among individuals with a history of chronic bronchitis (OR = 2.0, 95% CI = 1.5-2.5), emphysema (OR = 1.9, 95% CI = 1.4-2.8), or COPD (OR = 2.5, 95% CI = 2.0-3.1). Among current smokers, association between chronic bronchitis and lung cancer was strongest among lighter smokers. Asthma was associated with a decreased risk of lung cancer in males (OR = 0.48, 95% CI = 0.30-0.78).

CONCLUSIONS/SIGNIFICANCE

These results suggest that the associations of personal history of chronic bronchitis, emphysema, and COPD with increased risk of lung cancer are not entirely due to smoking. Inflammatory processes may both contribute to COPD and be important for lung carcinogenesis.

Overweight women and management of asthma

PURPOSE

We sought to describe clinical and psychosocial characteristics of overweight women with asthma.

METHODS

Telephone interview and medical record review involving 808 women with asthma participating in a randomized study to identify those who were overweight. We assessed the relationship of their weight to asthma symptoms, health care use, quality of life, self-esteem, need for social support, and demographic characteristics. Regression analyses were used to investigate relationships between overweight and asthma.

FINDINGS

Sixty-eight percent of the women in the study were overweight or obese. Demographic characteristics associated with overweight in women with asthma included being minority (p=.000), having a lower education level (p=.000), and a lower household income (p=.024). Overweight was associated with greater health care use, comorbidities (acid reflux, urinary incontinence), and persistent disease (p=.001). Overweight women exhibited lower self-esteem (p=.002) and lower perceived quality of life (p=.000).

CONCLUSION

Overweight females with asthma experience significant challenges because of their weight, more persistent and severe disease, specific comorbidities, and lower rates of obtaining psychosocial resources. Clinical consultations and interventions should account for the influence of overweight on asthma control and health status in female patients.