Effects of the menstrual cycle on lung function variables in women with asthma

Life Course of Asthma

Asthma is a heterogeneous chronic airway disease that can vary over a lifetime. Although broad categories of asthma by severity and type have been constructed, there remains a tremendous opportunity to discover an approach to managing asthma with additional factors in mind. Many in the field have suggested and are pursuing a novel paradigm shift in how asthma might be better managed, considering the life course of exposures, management priorities, and predicted trajectory of lung function growth. This approach will require a more holistic view of prenatal, postnatal, adolescence, hormonal and gender aspects, and the aging process. In addition, the environment, externally and internally, including in one's genetic code and epigenetic changes, are factors that affect how asthma progresses or becomes more stable in individuals. This chapter focuses on the various influences that may, to differing degrees, affect people with asthma, which can develop at any time in their lives. Shifting the paradigm of thought and strategies for care and advocating for public policies and health delivery that focus on this philosophy is paramount to advance asthma care for all.

A population-based cohort study on the risk of obstructive lung disease after bilateral oophorectomy

There is increasing evidence that sex hormones may impact the development of obstructive lung disease (OLD). Therefore, we studied the effect of bilateral oophorectomy (oophorectomy) on the development of OLD. Women were identified from the Mayo Clinic Cohort Study of Oophorectomy and Aging-2. Data were collected using the Rochester Epidemiology Project records-linkage system. A total of 1653 women who underwent oophorectomy and 1653 referent women of similar age were assessed for OLD using diagnostic codes and medical record abstraction. Women who underwent oophorectomy had an overall higher risk of all OLD, all chronic obstructive pulmonary disease (COPD), emphysema, and chronic bronchitis but not of all asthma, confirmed asthma, or confirmed COPD. The association with all OLD was stronger in women who were age ≤45 years at oophorectomy, never smokers, non-obese, and in women with benign indications; however, the interactions were not statistically significant. There was an increased risk of all asthma in women age ≤45 years at oophorectomy who took estrogen therapy. Never smokers of all ages had a stronger association of oophorectomy with all asthma and all COPD, whereas smokers had a stronger association of oophorectomy with emphysema and chronic bronchitis. Non-obese women of all ages had a stronger association of oophorectomy with all COPD, emphysema, and chronic bronchitis. The results of this study combined with the increased risk of several chronic diseases reported in previous studies suggest that oophorectomy in premenopausal women should be avoided unless there is clear evidence of a high genetic risk of ovarian cancer.

Menstrual cycle impacts lung structure measures derived from quantitative computed tomography

OBJECTIVE

Quantitative computed tomography (qCT) is being increasingly incorporated in research studies and clinical trials aimed at understanding lung disease risk, progression, exacerbations, and intervention response. Menstrual cycle-based changes in lung function are recognized; however, the impact on qCT measures is currently unknown. We hypothesize that the menstrual cycle impacts qCT-derived measures of lung structure in healthy women and that the degree of measurement change may be mitigated in subjects on cyclic hormonal birth control.

METHODS

Thirty-one non-smoking, healthy women with regular menstrual cycles (16 of which were on cyclic hormonal birth control) underwent pulmonary function testing and qCT imaging at both menses and early luteal phase time points. Data were evaluated to identify lung measurements which changed significantly across the two key time points and to compare degree of change across metrics for the sub-cohort with versus without birth control.

RESULTS

The segmental airway measurements were larger and mean lung density was higher at menses compared to the early luteal phase. The sub-cohort with cyclic hormonal birth control did not have less evidence of measurement difference over the menstrual cycle compared to the sub-cohort without hormonal birth control.

CONCLUSIONS

This study provides evidence that qCT-derived measures from the lung are impacted by the female menstrual cycle. This indicates studies seeking to use qCT as a more sensitive measure of cross-sectional differences or longitudinal changes in these derived lung measurements should consider acquiring data at a consistent time in the menstrual cycle for pre-menopausal women and warrants further exploration.

KEY POINTS

• Lung measurements from chest computed tomography are used in multicenter studies exploring lung disease progression and treatment response. • The menstrual cycle impacts lung structure measurements. • Cyclic variability should be considered when evaluating longitudinal change with CT in menstruating women.

Sex, gender and the pulmonary physiology of exercise

In this review, we detail how the pulmonary system's response to exercise is impacted by both sex and gender in healthy humans across the lifespan. First, the rationale for why sex and gender differences should be considered is explored, and then anatomical differences are highlighted, namely that females typically have smaller lungs and airways than males. Thereafter, we describe how these anatomical differences can impact functional aspects such as respiratory muscle energetics and activation, mechanical ventilatory constraints, diaphragm fatigue, and pulmonary gas exchange in healthy adults and children. Finally, we detail how gender can impact the pulmonary response to exercise.

Biological sex can influence the pulmonary response to exercise in healthy individuals across the lifespanhttps://bit.ly/3ejMDrv

Sex and gender in asthma

Asthma is a heterogenous disease, and its prevalence and severity are different in males versus females through various ages. As children, boys have an increased prevalence of asthma. As adults, women have an increased prevalence and severity of asthma. Sex hormones, genetic and epigenetic variations, social and environmental factors, and responses to asthma therapeutics are important factors in the sex differences observed in asthma incidence, prevalence and severity. For women, fluctuations in sex hormone levels during puberty, the menstrual cycle and pregnancy are associated with asthma pathogenesis. Further, sex differences in gene expression and epigenetic modifications and responses to environmental factors, including SARS-CoV-2 infections, are associated with differences in asthma incidence, prevalence and symptoms. We review the role of sex hormones, genetics and epigenetics, and their interactions with the environment in the clinical manifestations and therapeutic response of asthma.

Role of Sex Hormones at Different Physiobiological Conditions and Therapeutic Potential in MBD2 Mediated Severe Asthma

Sex hormone has become a “hot topic” to evaluate the hormonal therapeutic potential in severe asthma. Th17 cell is one of the main influencing factors involved in the pathogenesis of severe asthma, hence also called as kernel of severe asthma, and Th17 subtype of non-T2 asthma is less responsive (resistance) to inhaled corticosteroid (ICS), so severe in nature. Methyl-CpG binding domain protein 2 (MBD2) is overexpressed and regulates the Th17 differentiation, showing the possibility of therapeutic target in treating Th17 mediated severe asthma. Sex hormone fluctuates at the different physiobiological conditions of the human body and affects the asthma pathobiology showing its role in asthma prevalence, severity, remission, and therapy. This review briefly overviews the sex hormones, their influence in asthma at the different physiobiological conditions of human body, and MBD2 severe asthma connection with the possible therapeutic potential of sex steroids in MBD2 mediated Th17 predominant severe asthma. Male sex hormone tends to show a beneficial effect and possibly downregulates the expression of Th17 cells via regulating MBD2 through a mechanism distinct from corticosteroid treatment and guides us towards discovery of new therapeutic agent, reduces the asthma-related complications, and promotes long-term survival by lowering the risk of therapy-resistant issues of old age severe asthma.

Insights from the Menstrual Cycle in Pulmonary Arterial Hypertension

Rationale: Sex hormones play a role in pulmonary arterial hypertension (PAH), but the menstrual cycle has never been studied.Objectives: We conducted a prospective observational study of eight women with stable PAH and 20 healthy controls over one cycle.Methods: Participants completed four study visits 1 week apart starting on the first day of menstruation. Relationships between sex hormones, hormone metabolites, and extracellular vesicle microRNA (miRNA) expression and clinical markers were compared with generalized linear mixed modeling.Results: Women with PAH had higher but less variable estradiol (E2) levels (P < 0.001) that tracked with 6-minute walk distance (P < 0.001), N-terminal prohormone of brain natriuretic peptide (P = 0.03) levels, and tricuspid annular plane systolic excursion (P < 0.01); the direction of these associations depended on menstrual phase. Dehydroepiandrosterone sulfate (DHEA-S) levels were lower in women with PAH (all visits, P < 0.001). In PAH, each 100-μg/dl increase in DHEA-S was associated with a 127-m increase in 6-minute walk distance (P < 0.001) and was moderated by the cardioprotective E2 metabolite 2-methoxyestrone (P < 0.001). As DHEA-S increased, N-terminal prohormone of brain natriuretic peptide levels decreased (P = 0.001). Expression of extracellular vesicle miRNAs-21, -29c, and -376a was higher in PAH, moderated by E2 and DHEA-S levels, and tracked with hormone-associated changes in clinical measures.Conclusions: Women with PAH have fluctuations in cardiopulmonary function during menstruation driven by E2 and DHEA-S. These hormones in turn influence transcription of extracellular vesicle miRNAs implicated in the pathobiology of pulmonary vascular disease and cancer.

A Prospective Study of the Effects of Sex Hormones on Lung Function and Inflammation in Women with Cystic Fibrosis

Rationale: Epidemiologic studies demonstrate worse outcomes in women with cystic fibrosis (CF) than men. Women are colonized earlier with respiratory pathogens and have increased rates of pulmonary exacerbations after puberty and near ovulation. The etiology of this disparity is unclear, but sex hormones may contribute to these differences.Objectives: We sought to explore whether natural hormonal fluctuations and hormonal contraception associate with changes in lung function, respiratory symptoms, or inflammatory markers.Methods: We prospectively followed women with CF who were not on hormonal contraceptives and reported regular menstrual cycles. We captured study visits at points that corresponded with menses, ovulation, and the luteal phase. A subset of subjects were subsequently placed on a standard oral estrogen/progesterone combination contraceptive pill, ethinyl estradiol/norethindrone (loestrin), and reevaluated. Measurements included lung function, symptom questionnaires, sweat tests, blood for hormone concentrations, and sputum for inflammatory markers, bacterial density, and cytology.Results: Twenty-three women participated in this study. Hormone concentrations were as expected on and off hormonal contraception. At times of peak estrogen (ovulation), there was a significant increase in sputum proinflammatory cytokines (neutrophil-free elastase) and a corresponding pattern of decrease in lung function. Proinflammatory cytokines (IL-8, TNF-α, and neutrophil-free elastase) improved when placed on hormone contraception.Conclusions: Our results show that there are potentially important fluctuations in inflammatory biomarkers in the lungs that correlate with changes in lung function in women with CF. Larger studies evaluating the impact of sex hormones on airway inflammation and immune response are necessary to better understand the clinical impact of these responses.

Sex Hormones and Lung Inflammation

Inflammation is a characteristic marker in numerous lung disorders. Several immune cells, such as macrophages, dendritic cells, eosinophils, as well as T and B lymphocytes, synthetize and release cytokines involved in the inflammatory process. Gender differences in the incidence and severity of inflammatory lung ailments including asthma, chronic obstructive pulmonary disease (COPD), pulmonary fibrosis (PF), lung cancer (LC), and infectious related illnesses have been reported. Moreover, the effects of sex hormones on both androgens and estrogens, such as testosterone (TES) and 17β-estradiol (E2), driving characteristic inflammatory patterns in those lung inflammatory diseases have been investigated. In general, androgens seem to display anti-inflammatory actions, whereas estrogens produce pro-inflammatory effects. For instance, androgens regulate negatively inflammation in asthma by targeting type 2 innate lymphoid cells (ILC2s) and T-helper (Th)-2 cells to attenuate interleukin (IL)-17A-mediated responses and leukotriene (LT) biosynthesis pathway. Estrogens may promote neutrophilic inflammation in subjects with asthma and COPD. Moreover, the activation of estrogen receptors might induce tumorigenesis. In this chapter, we summarize the most recent advances in the functional roles and associated signaling pathways of inflammatory cellular responses in asthma, COPD, PF, LC, and newly occurring COVID-19 disease. We also meticulously deliberate the influence of sex steroids on the development and progress of these common and severe lung diseases.

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.

Asthma in the Real-World: The Relevance of Gender

BACKGROUND

The possible gender impact on asthma arouses current and outstanding interest, but few studies addressed this issue in the real-world setting.

OBJECTIVE

This cross-sectional study tested the hypothesis of a potential difference between asthmatic males and females in a real-life setting, such as a third-level asthma clinic.

METHODS

A total of 499 asthmatic outpatients (301 females and 198 males, mean age 58.25 years) were consecutively visited. The visit included history, asthma control, and severity grade, physical examination, lung function, fractional exhaled nitric oxide assessment, and blood sample for biomarkers.

RESULTS

There were more females than males (about 3 of 5). Asthmatic females smoked less (p < 0.0001) than males and had higher FEV1 (p = 0.0022) and FVC (p = 0.0004) values than asthmatic males.

CONCLUSIONS

Gender difference was associated with smoking and lung function impairment; thus, this issue should be carefully considered in asthmatic patients in daily clinical practice.

Biological sex influences susceptibility to Acinetobacter baumannii pneumonia in mice

Acinetobacter baumannii (A. baumannii) is an extremely versatile multidrug-resistant pathogen with a very high mortality rate; therefore, it has become crucial to understand the host response during its infection. Given the importance of mice for modeling infection and their role in preclinical drug development, equal emphasis should be placed on the use of both sexes. Through our studies using a murine model of acute pneumonia with A. baumannii, we observed that female mice were more susceptible to infection. Likewise, treatment of male mice with estradiol increased their susceptibility to infection. Analysis of the airway compartment revealed enhanced inflammation and reduced neutrophil and alveolar macrophage numbers compared with male mice. Depletion of either neutrophils or alveolar macrophages was important for bacterial clearance; however, depletion of alveolar macrophages further exacerbated female susceptibility because of severe alterations in metabolic homeostasis. Our data highlight the importance of using both sexes when assessing host immune pathways.

Perimenstrual Asthma in Aspirin-Exacerbated Respiratory Disease

BACKGROUND

Aspirin-exacerbated respiratory disease (AERD) is a condition of the upper and lower respiratory tract characterized by reactions to nonsteroidal anti-inflammatory drugs. The Severe Asthma Research Program reported a strong association between perimenstrual asthma (PMA) and aspirin-sensitive asthma.

OBJECTIVE

To evaluate the prevalence and characteristics of PMA among a cohort of patients with AERD.

METHODS

Women 18 years and older enrolled in the Brigham and Women's AERD registry were surveyed about their reproductive, asthma, and sinus history. Subjects reporting the development of asthma before menopause were included. Continuous and categorical variables were compared between those reporting menstruation as a trigger for asthma symptoms and those who did not. Covariates expected a priori to have a positive effect on the odds of PMA were included in a multivariate logistic regression model to test associations between PMA and clinical factors.

RESULTS

Among females of childbearing potential, 369 of 695 responded to the survey and 322 met inclusion criteria. Twenty-four percent of subjects (n = 74) reported PMA. Earlier age of AERD onset, concurrent worsening of sinus symptoms the week before or during menstruation, increased emergency department visits for asthma, and a change in the severity of respiratory symptoms at menopause were more common in PMA. Earlier age at first nonsteroidal anti-inflammatory drug-induced respiratory reaction and emergency department visits increased the odds of reporting PMA.

CONCLUSIONS

PMA and increased sinus symptoms with menstruation are common in females with AERD. Females with AERD should be counseled about upper and lower respiratory symptom deterioration with menstruation.

Novel Insights on Sex-Related Differences in Asthma

PURPOSE OF REVIEW

Asthma, a common respiratory disease that affects about 10% of the US population, represents a significant public health issue. In the last decade, cumulative evidence has demonstrated sex disparities in asthma, including significant differences in epidemiology, clinical presentation, response to therapies, and health outcomes. Understanding sex-related differences in asthma enables clinicians to provide personalized asthma care and improve asthma outcome.

RECENT FINDINGS

Recent studies on sex-related differences in asthma inform us on mechanism underlying asthma pathogenesis across all age groups. Sex hormones directly modulate immune pathways crucial in asthma pathogenesis and affect individual's response to environmental triggers and medications, such as leukokotriene inhibitors. Not surprisingly, the use of external sex hormone supplementations appears to modulate asthma risk. Identification of sex-specific asthma risk loci through genome-wide association studies also provides supporting evidence on sex-related differences in asthma. There is an interaction between sex and obesity, an interaction that could place females at higher risk for systemic inflammation and, consequently, asthma. In this article, we review epidemiological and clinical studies on sex-related differences in asthma, with a special focus on the role of sex hormones, including hormonal therapies and the asthma-obesity interaction.

Modulation of the lung inflammatory response to ozone by the estrous cycle

Emerging evidence suggests that sex differences exist in the control of lung innate immunity; however, the specific roles of sex hormones in the inflammatory response, and the mechanisms involved are unclear. Here, we investigated whether fluctuations in circulating hormone levels occurring in the mouse estrous cycle could affect the inflammatory response to air pollution exposure. For this, we exposed female mice (C57BL/6J, 8 weeks old) at different phases of the estrous cycle to 2 ppm of ozone or filtered air (FA) for 3 h. Following exposure, we collected lung tissue and bronchoalveolar lavage fluid (BAL), and performed lung function measurements to evaluate inflammatory responses and respiratory mechanics. We found a differential inflammatory response to ozone in females exposed in the luteal phase (metestrus, diestrus) versus the follicular phase (proestrus, estrus). Females exposed to ozone in the follicular phase had significantly higher expression of inflammatory genes, including Ccl2, Cxcl2, Ccl20, and Il6, compared to females exposed in the luteal phase (P < 0.05), and displayed differential activation of regulatory pathways. Exposure to ozone in the follicular phase also resulted in higher BAL neutrophilia, lipocalin levels, and airway resistance than exposure in the luteal phase (P < 0.05). Together, these results show that the effects of ozone exposure in the female lung are affected by the estrous cycle phase, and potentially hormonal status. Future studies investigating air pollution effects and inflammation in women should consider the menstrual cycle phase and/or circulating hormone levels.

Life Cycle of Childhood Asthma: Prenatal, Infancy and Preschool, Childhood, and Adolescence

Asthma is a heterogeneous developmental disorder influenced by complex interactions between genetic susceptibility and exposures. Wheezing in infancy and early childhood is highly prevalent, with a substantial minority of children progressing to established asthma by school age, most of whom are atopic. Adolescence is a time of remission of symptoms with persistent lung function deficits. The transition to asthma in adulthood is not well understood.

Asthma over the Adult Life Course: Gender and Hormonal Influences

Asthma is a common disorder that affects genders differently across the life span. Earlier in life, it is more common in boys. At puberty, asthma becomes more common and often more severe in girls and women. The effect of sex hormones on asthma incidence and its severity is difficult to differentiate from other asthma severity risk factors, such as racial background, socioeconomic factors, obesity, atopy, environmental exposure, and, in particular, lung aging. Recognizing gender-associated and age-associated differences is important to understanding the pathobiology of asthma and to providing effective education and personalized care for patients with asthma across the life course.

Role of estrogen receptors α and β in the development of allergic airway inflammation in mice: A possible involvement of interleukin 33 and eosinophils

Recent studies have shown that the estrogen receptor α (ERα), but not ERβ, is involved in the proinflammatory and propruritic responses in cutaneous allergy. In addition, results from our recent study showed that while oral administration of the rather ERβ-selective agonist bisphenol A exacerbated the respiratory allergic inflammation, the potential inflammatory reaction in the skin was decreased after administration of bisphenol A. This study aimed to elucidate whether ERα and ERβ are involved in the progression of an allergic airway inflammation. We performed an in vivo experiment using an animal model of allergic airway inflammation using male BALB/c mice to confirm an increase in the proinflammatory response induced by propylpyrazoletriol (PPT), an ERα agonist, and diarylpropionitrile (DPN), an ERβ agonist. Oral administration of PPT or DPN showed a significant increase in the inflammation of the lung and infiltration of eosinophils. While the expression of Th2 cytokines such as interleukin 4 (IL-4) and IL-13 was not affected by exposure to PPT or DPN, administration of these agonists significantly increased the expression of IL-33. The mechanism underlying the development of such allergic inflammatory responses was determined by an in vitro study using the human bronchial epithelial cell line (BEAS-2B) and the human eosinophilic leukemia cell line (EoL-1). Activated cells were exposed to PPT or DPN for 24 h, and the cytokine levels were measured. The IL-33 levels in BEAS-2B cells increased significantly after exposure to PPT or DPN. In addition, pretreatment with PPT or DPN increased the expression of IL-8 in activated EoL-1 cells. Our findings indicate that ERα and ERβ are involved in the proinflammatory response in respiratory allergy, and their effects may be mediated by an increase in the expression of IL-33 and infiltration of eosinophils.

Asthma control, lung function, nutritional status, and health-related quality of life: differences between adult males and females with asthma

OBJECTIVE

To evaluate health-related quality of life in asthma patients treated at a referral center in southern Brazil, identifying differences between male and female patients, as well as to evaluate differences between the males and females in terms of asthma control, lung function, and nutritional status.

METHODS

This was a cross-sectional study involving patients ≥ 18 years of age treated at an asthma outpatient clinic. We evaluated clinical parameters, lung function, nutritional status, and quality of life.

RESULTS

A total of 198 patients completed the study. The mean age was 56.2 ± 14.8 years, and 81.8% were female. The proportion of patients with uncontrolled asthma was higher among females than among males (63.0% vs. 44.4%; p = 0.041). The body mass index (BMI) and percentage of body fat were higher in females than in males (30.2 ± 5.8 kg/m2 vs. 26.9 ± 4.5 kg/m2 and 37.4 ± 6.4% vs. 26.5 ± 7.4%; p = 0.002 and p < 0.001, respectively). Quality of life was lower in females than in males in the following domains: symptoms (3.8 ± 1.5 vs. 4.6 ± 1.7; p = 0.006); activity limitation (3.6 ± 1.3 vs. 4.4 ± 1.5; p = 0.001); emotional function (3.6 ± 1.9 vs. 4.5 ± 1.7; p = 0.014); and environmental stimuli (3.2 ± 1.6 vs. 4.3 ± 1.9; p = 0.001).

CONCLUSIONS

Male asthma patients appear to fare better than do female asthma patients in terms of health-related quality of life, asthma control, BMI, percentage of body fat, and comorbidities.

Sex-specific microRNA expression networks in an acute mouse model of ozone-induced lung inflammation

BACKGROUND

Sex differences in the incidence and prognosis of respiratory diseases have been reported. Studies have shown that women are at increased risk of adverse health outcomes from air pollution than men, but sex-specific immune gene expression patterns and regulatory networks have not been well studied in the lung. MicroRNAs (miRNAs) are environmentally sensitive posttranscriptional regulators of gene expression that may mediate the damaging effects of inhaled pollutants in the lung, by altering the expression of innate immunity molecules.

METHODS

Male and female mice of the C57BL/6 background were exposed to 2 ppm of ozone or filtered air (control) for 3 h. Female mice were also exposed at different stages of the estrous cycle. Following exposure, lungs were harvested and total RNA was extracted. We used PCR arrays to study sex differences in the expression of 84 miRNAs predicted to target inflammatory and immune genes.

RESULTS

We identified differentially expressed miRNA signatures in the lungs of male vs. female exposed to ozone. In silico pathway analyses identified sex-specific biological networks affected by exposure to ozone that ranged from direct predicted gene targeting to complex interactions with multiple intermediates. We also identified differences in miRNA expression and predicted regulatory networks in females exposed to ozone at different estrous cycle stages.

CONCLUSION

Our results indicate that both sex and hormonal status can influence lung miRNA expression in response to ozone exposure, indicating that sex-specific miRNA regulation of inflammatory gene expression could mediate differential pollution-induced health outcomes in men and women.

Effects of endogenous sex hormones on lung function and symptom control in adolescents with asthma

BACKGROUND

Although pre-puberty asthma is more prevalent in males, after puberty through middle-age, asthma is more prevalent in females. The surge of sex hormones with puberty might explain this gender switch.

METHODS

To examine the effects of sex hormones on lung function and symptoms with puberty, Tanner stage was assessed in 187 children 6-18 years of age (59% severe) enrolled in the NIH/NHLBI Severe Asthma Research Program (SARP). The effects of circulating sex hormones (n = 68; testosterone, dehydroepiandrosterone sulfate (DHEA-S), estrogen, and progesterone) on lung function and 4 week symptom control (ACQ6) in cross-section were tested by linear regression.

RESULTS

From pre-/early to late puberty, lung function did not change significantly but ACQ6 scores improved in males with severe asthma. By contrast females had lower post-BD FEV₁% and FVC% and worse ACQ6 scores with late puberty assessed by breast development. In males log DHEA-S levels, which increased by Tanner stage, associated positively with pre- and post-BD FEV₁%, pre-BD FVC %, and negatively (improved) with ACQ6. Patients treated with high-dose inhaled corticosteroids had similar levels of circulating DHEA-S. In females, estradiol levels increased by Tanner stage, and associated negatively with pre-BD FEV₁% and FVC %.

CONCLUSIONS

These results support beneficial effects of androgens on lung function and symptom control and weak deleterious effects of estradiol on lung function in children with asthma. Longitudinal data are necessary to confirm these cross-sectional findings and to further elucidate hormonal mechanisms informing sex differences in asthma features with puberty.

TRIAL REGISTRATION

ClinicalTrials.gov registration number: NCT01748175 .

Incidence of asthma in young adults from Castellon, Spain: A prospective cohort study

BACKGROUND

The objective was to estimate the incidence of asthma in young adults from 13-15 years old to 23-25 years old, and associated factors.

METHODS

In 2012, a population-based prospective cohort study was carried out in Castellon from the cohort who had participated in the International Study of Asthma and Allergy in Childhood in 1994 and 2002. A telephone survey was undertaken using the same questionnaires. A new case of asthma was defined as a participant free of the disease in 2002 who suffered asthma, was diagnosed with asthma, or took medications against asthma based on self-report from 2002 to 2012.

RESULTS

The mean age of participants was 24.9±0.6 with a follow-up of 79.1%. Asthma cumulative incidence was 3.4%: 44 new cases occurred among 1280 participants. The incidence was higher in females than males with relative risk (RR)=2.02 (95% confidence interval [CI] 1.1-3.8). A significant decrease of asthma incidence density was observed (8.2 cases to 3.5 cases per 1000 person/year). Factors associated with the incidence of asthma were allergic rhinitis (RR=4.05; 95% CI 1.7-9.6), bronchitis (RR=2.13; 95% CI 1.0-4.5), mother's age at time of birth (RR=0.87; 95% CI 0.8-0.9) and a pet other than a dog or cat (RR=0.42; 95% CI 0.2-0.9). For gender, some variations in the risk factors were observed.

CONCLUSIONS

A significant decrease in the incidence of asthma was observed. Several risk and protective factors were found.

Studying allergic inflammation and spirometry over menstrual cycles in well-controlled asthmatic women: Changes in progesterone and estradiol affect neither FENO levels nor lung function

It has been reported that female sex hormones influence on allergic inflammation and ventilation parameters in asthma but conclusions drawn by different researchers are divergent. The aim of our study was to assess the impact of progesterone (Pg) and estradiol (E) on the dynamics of allergic inflammation and spirometry test results in regularly menstruating women with stable allergic asthma. 13 women (28 days menstrual cycle), aged 18-45, taking no hormonal contraceptives, with mild and moderate asthma, without reported exacerbations at the near-ovulation and/or menstruation time, were monitored during two consecutive menstrual cycles. They had 4 visits per cycle (the first day of menstruation was assumed to be day 1 of the cycle; visits were carried out on days: 3-4, 10-11, 13-14 and 23-24). At each visit asthma symptoms, asthma control test (ACT) results, asthma treatment, fractioned nitric oxide (FENO) levels, spirometry test results, Pg and E, levels were analyzed. As a result of the study, no essential variability in FENO values and ventilation parameters' values in the course of menstruation cycle were observed. Negative correlation between FENO values and Pg concentrations was demonstrated (r = 0.27), but no correlation between FENO values and E levels was shown. No relationship between the ACT values and ventilation parameters and the levels of the sex hormones under investigation was detected. We conclude that changing levels of estradiol and progesterone (regardless of the negative correlation of progesterone and FENO values) affect neither the dynamics of allergic inflammation nor pulmonary function in women with stable allergic mild/moderate asthma.

The impact of gender on asthma in the daily clinical practice

OBJECTIVES

It is up-to-date to consider the potential gender impact on a disease. There are few data about gender difference in asthma. Therefore, the present cross-sectional study tested this hypothesis in a real-life setting to investigate possible difference between genders.

METHODS

This study was cross-sectional, considering 554 consecutive outpatients suspected of asthma, who were referred for a first specialist visit. Clinical and functional parameters were evaluated.

RESULTS

Females with asthma could have a worse perception of asthma control, assessed by asthma control test (ACT), and more anxiety than asthmatic males. However, there was no difference regarding asthma control grading, asthma severity, and asthma medication use between genders; the differences in lung function were without clinical relevance.

CONCLUSIONS

In the daily clinical practice, it is relevant to consider gender in the management of asthma.

17β-Estradiol Promotes Apoptosis in Airway Smooth Muscle Cells Through CD38/SIRT1/p53 Pathway

17β-Estradiol (E2) is the major estrogen secreted by the premenopausal ovary and shows dual effects on cell apoptosis under pathological conditions. E2 was previously shown to increase CD38 mRNA and protein expression in myometrial smooth muscle, but its function and mechanism remain largely unknown. Here we investigated the role of E2 in hypoxia-induced apoptosis in mouse airway smooth muscle cells (ASMCs) and explored the underlying mechanisms. Results showed that E2 significantly increased CD38 expression at both mRNA and protein levels, accompanied with decreased SIRT1 levels in ASMCs. By using primary ASMCs from the wild type (WT) and the smooth muscle-specific CD38 knockout (CD38 KO) mice, we found that the down-regulation of SIRT1 induced by E2 was abolished in CD38 KO AMSCs. E2 promoted the acetylation of p53 in WT cells, and this effect was also diminished in the absence of CD38. In addition, E2 further activated CD38/SIRT1/p53 signal pathway and promoted cell apoptosis during hypoxia. However, these effects were reversed in CD38 KO ASMCs and by the specific SIRT1 activator Resveratrol. We also found that E2 enhanced CD38 expression through estrogen receptor. The data suggested that CD38 is a direct target for E2 which promotes hypoxia-induced AMSC apoptosis through SIRT1/p53 signal pathway.

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.

Women's Health and Lung Development and Disease

Although the lung is not traditionally thought of as an organ affected by sex-based differences, emerging literature elucidates major differences between men and women in the development, physiology, and predilection to and outcomes in lung diseases. These differences are driven by both differences in sex hormones and differences in environmental exposures. However, in many cases the underlying etiology of these sex- and gender-based differences is unknown. This article outlines the state-of-the-art knowledge on the etiology of sex differences in lung disease, including differences in lung development and physiology, and reviews therapy recommendations that are sex based.

Menopause Is Associated with Accelerated Lung Function Decline

RATIONALE

Menopause is associated with changes in sex hormones, which affect immunity, inflammation, and osteoporosis and may impair lung function. Lung function decline has not previously been investigated in relation to menopause.

OBJECTIVES

To study whether lung function decline, assessed by FVC and FEV₁, is accelerated in women who undergo menopause.

METHODS

The population-based longitudinal European Community Respiratory Health Survey provided serum samples, spirometry, and questionnaire data about respiratory and reproductive health from three study waves (n = 1,438). We measured follicle-stimulating hormone and luteinizing hormone and added information on menstrual patterns to determine menopausal status using latent class analysis. Associations with lung function decline were investigated using linear mixed effects models, adjusting for age, height, weight, pack-years, current smoking, age at completed full-time education, spirometer, and including study center as random effect.

MEASUREMENTS AND MAIN RESULTS

Menopausal status was associated with accelerated lung function decline. The adjusted mean FVC decline was increased by -10.2 ml/yr (95% confidence interval [CI], -13.1 to -7.2) in transitional women and -12.5 ml/yr (95% CI, -16.2 to -8.9) in post-menopausal women, compared with women menstruating regularly. The adjusted mean FEV₁ decline increased by -3.8 ml/yr (95% CI, -6.3 to -2.9) in transitional women and -5.2 ml/yr (95% CI, -8.3 to -2.0) in post-menopausal women.

CONCLUSIONS

Lung function declined more rapidly among transitional and post-menopausal women, in particular for FVC, beyond the expected age change. Clinicians should be aware that respiratory health often deteriorates during reproductive aging.

Addressing unmet needs in understanding asthma mechanisms: From the European Asthma Research and Innovation Partnership (EARIP) Work Package (WP)2 collaborators

Asthma is a heterogeneous, complex disease with clinical phenotypes that incorporate persistent symptoms and acute exacerbations. It affects many millions of Europeans throughout their education and working lives and puts a heavy cost on European productivity. There is a wide spectrum of disease severity and control. Therapeutic advances have been slow despite greater understanding of basic mechanisms and the lack of satisfactory preventative and disease modifying management for asthma constitutes a significant unmet clinical need. Preventing, treating and ultimately curing asthma requires co-ordinated research and innovation across Europe. The European Asthma Research and Innovation Partnership (EARIP) is an FP7-funded programme which has taken a co-ordinated and integrated approach to analysing the future of asthma research and development. This report aims to identify the mechanistic areas in which investment is required to bring about significant improvements in asthma outcomes.

Allergic diseases, smoking, and environmental exposure among university students in Lebanon

INTRODUCTION

Smoking habits among university students in Lebanon are not clearly identified, and studies correlating these habits to asthma and allergic diseases are lacking. The primary objective of this study is to assess asthma and allergic diseases' predictors, particularly cigarette and/or waterpipe smoking and other environmental exposures, among university students. A second objective is to evaluate the potential role of these predictors as correlates of health-related self-assessment.

METHODS

A cross-sectional study, using a proportionate cluster sample of 3000 Lebanese students in both public and private universities, was conducted between January 2015 and December 2015.

RESULTS

The number of smokers at home, living close to an electricity generator and exposure to sand and dust significantly increased the odds of having asthma or allergic diseases (p = 0.015; OR = 1.183; p = 0.01; OR = 2.062; p = 0.001; OR = 3.558 respectively). Having tried cigarette smoking and having an air conditioner inside the means of transportation would decrease the odds of having asthma or allergic diseases by around 68% and 56.1% respectively (p = 0.009; OR_a = 0.320; p = 0.01; OR_a = 0.439 respectively).

CONCLUSION

Although students with asthma or allergic diseases tended to avoid all identifiable atopic risk factors, lesser known environmental factors such as living close to an electricity generator, exposure to sand and dust, and exposure to car exhaust fumes were associated with a higher risk of asthma and a decrease in health related self-assessment. Students with asthma and allergic diseases smoked cigarettes and waterpipe at similar percentages, but cigarette smokers had a lower health related self-assessment.

Asthma in adolescence: Is there any news?

Asthma is a chronic disease that has a significant impact quality of life, which is particularly important in adolescence. We will discuss aspects of epidemiology, the clinical spectrum, diagnostics, and management of asthma in adolescence. In particular, we will highlight the psychological implications of having asthma during this developmental period. Data published in the past 10 years, since we last reviewed the subject, will be the main focus of this paper. The care of the teenager with asthma should take into account the rapid physical, emotional, cognitive, and social changes that occur during normal adolescence. The diagnostic process may be more difficult since teenagers tend to deny their illness. Thus, both under-diagnosis and under-assessment of asthma severity may lead to under-treatment and potentially avoidable morbidity and even mortality. Conversely, teenagers may be often misdiagnosed as having asthma or their asthma severity may be overestimated leading to inappropriate and sometimes excessive treatment. Educational programs, environmental avoidance measures, proper use of medications along with a skilled approach, and a caring attitude of health providers are all very important for successful management. Pediatr Pulmonol. 2017;52:129-138. © 2016 Wiley Periodicals, Inc.

Severe Asthma in Children: Lessons Learned and Future Directions

Severe asthma in children is a complicated and heterogeneous disorder that is extremely challenging to treat. Although most children with asthma derive clinical benefit from daily administration of low-to-medium-dose inhaled corticosteroid (ICS) therapy, a small subset of children with "severe" or "refractory" asthma require high doses of ICS and even systemic corticosteroids to maintain symptom control. These children with severe asthma are at increased risk for adverse outcomes including medication-related side effects and recurrent and life-threatening exacerbations that significantly impair quality of life. This review highlights findings on severe asthma in school-age children (age 6-17 years) from the National Heart, Lung and Blood Institute's Severe Asthma Research Program (SARP) over a 10-year period, between 2001 and 2011. Although SARP has advanced knowledge of the unique clinical, biological, and molecular attributes of severe asthma in children, considerable gaps remain for which additional studies are needed.

Asthma as a disruption in iron homeostasis

Over several decades, asthma has evolved from being recognized as a single disease to include a diverse group of phenotypes with dissimilar natural histories, pathophysiologies, responses to treatment, and distinctive molecular pathways. With the application of Occam's razor to asthma, it is proposed that there is one cause underlying the numerous phenotypes of this disease and that the responsible molecular pathway is a deficiency of iron in the lung tissues. This deficiency can be either absolute (e.g. asthma in the neonate and during both pregnancy and menstruation) or functional (e.g. asthma associated with infections, smoking, and obesity). Comparable associations between asthma co-morbidity (e.g. eczema, urticaria, restless leg syndrome, and pulmonary hypertension) with iron deficiency support such a shared mechanistic pathway. Therapies directed at asthma demonstrate a capacity to impact iron homeostasis, further strengthening the relationship. Finally, pathophysiologic events producing asthma, including inflammation, increases in Th2 cells, and muscle contraction, can correlate with iron availability. Recognition of a potential association between asthma and an absolute and/or functional iron deficiency suggests specific therapeutic interventions including inhaled iron.

Sex Differences in Airway Remodeling in a Mouse Model of Chronic Obstructive Pulmonary Disease

RATIONALE

After adjustment for the amount of smoking, women have a 50% increased risk of chronic obstructive pulmonary disease (COPD) compared with men. The anatomic basis and/or mechanism(s) of these sex-related differences in COPD are unknown.

OBJECTIVES

To characterize the impact of female sex hormones on chronic cigarette smoke-induced airway remodeling and emphysema in a mouse model of COPD.

METHODS

Airway remodeling and emphysema were determined morphometrically in male, female, and ovariectomized mice exposed to 6 months of cigarette smoke. Antioxidant- and transforming growth factor (TGF)-β-related genes were profiled in airway tissues. The selective estrogen receptor modulator tamoxifen was also administered during smoke exposure in a short-term model. Airway wall thickness of male and female human smokers at risk of or with mild COPD was measured using optical coherence tomography.

MEASUREMENTS AND MAIN RESULTS

Small airway wall remodeling was increased in female but not male or ovariectomized mice and was associated with increased distal airway resistance, down-regulation of antioxidant genes, increased oxidative stress, and activation of TGF-β1. These effects were prevented by ovariectomy. Use of tamoxifen as a therapeutic intervention mitigated smoke-induced increase in oxidative stress in female mice. Compared with male human smokers, female human smokers had significantly thicker airway walls.

CONCLUSIONS

The excess risk of small airway disease in female mice after chronic smoke exposure was associated with increased oxidative stress and TGF-β1 signaling and also was related to the effects of female sex hormones. Estrogen receptor antagonism might be of value in reducing oxidative stress in female smokers.

Clinically relevant subgroups in COPD and asthma

As knowledge of airways disease has grown, it has become apparent that neither chronic obstructive pulmonary disease (COPD) nor asthma is a simple, easily defined disease. In the past, treatment options for both diseases were limited; thus, there was less need to define subgroups. As treatment options have grown, so has our need to predict who will respond to new drugs. To date, identifying subgroups has been largely reported by detailed clinical characterisation or differences in pathobiology. These subgroups are commonly called "phenotypes"; however, the problem of defining what constitutes a phenotype, whether this should include comorbid diseases and how to handle changes over time has led to the term being used loosely. In this review, we describe subgroups of COPD and asthma patients whose clinical characteristics we believe have therapeutic or major prognostic implications specific to the lung, and whether these subgroups are constant over time. Finally, we will discuss whether the subgroups we describe are common to both asthma and COPD, and give some examples of how treatment might be tailored in patients where the subgroup is clear, but the label of asthma or COPD is not.

Prevalence of Asthma and Respiratory Symptoms among University Students in Sari (North of Iran)

BACKGROUND

Despite widely available data about childhood asthma, there are limited data about the prevalence of asthma among young adults in Iran. The aim of this study was to determine the prevalence of asthma and respiratory symptoms among medical students in the city of Sari in Northern Iran.

MATERIALS AND METHODS

The prevalence of asthma and respiratory symptoms was studied using a standard questionnaire. Based on the information obtained from the questionnaires, the study participants were divided into two groups of asthmatics and non-asthmatics. Pulmonary function tests including forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) before, and after salbutamol inhalation were measured in all subjects with asthma and approximately 10% of those without asthma.

RESULTS

A total of 1,011 subjects (374 males, 637 females) participated in this study. Asthma was found in 3.5% of the subjects (3.2% males and 3.6% females). The 12-month prevalence of wheezing, coughing at rest, coughing at night, breathlessness at rest, exercise-induced wheezing, and exercise-induced coughing in the entire study population was 11.1%, 12.4%, 13.4%, 13.3%, 17.7%, and 16.7%, respectively. The prevalence of all asthma-related symptoms was significantly higher among asthmatics compared to non-asthmatics. Moreover, asthmatic subjects showed lower FEV1 and FVC values compared to nonasthmatic subjects (P<0.001). Smoking and family history of asthma were statistically significant risk factors for developing asthma.

CONCLUSION

The high prevalence of asthma related symptoms in the present study strongly suggests that asthma is under diagnosed and under treated among participants.

Increasing awareness of sex differences in airway diseases

There is growing epidemiologic data demonstrating sex differences with respect to prevalence and progression of airway diseases, including asthma, chronic obstructive pulmonary disease (COPD), cystic fibrosis (CF) and non-CF-related bronchiectasis. In asthma, for example, young boys have increased exacerbations and higher morbidity than girls which distinctly reverses after adolescence and into adulthood. In COPD, a disease that was historically considered an illness of men, the number of women dying per year is now greater than in men. Finally, women with CF-related bronchiectasis have a decreased median life expectancy relative to men and a higher risk of respiratory infections despite equal prevalence of the disease. A number of studies now exist demonstrating mechanisms behind these sex differences, including influences of genetic predisposition, sex hormones and comorbidities. The notable sex disparity has potential diagnostic, therapeutic and prognostic implications and for the practicing respiratory or general physician, a familiarity with these distinctions may augment effective management of patients with airway diseases. This review seeks to concisely summarize the data regarding gender-based differences in airway diseases, outline the current understanding of contributing factors and discuss therapeutic implications for clinicians.

Questions relating to premenstrual asthma

The study of asthma in fertile women needs to consider its potentially recurrent exacerbation in a specific phase of the menstrual cycle. Premenstrual asthma (PMA) refers to the deterioration of asthma in some women of fertile age during the premenstrual phase. Prevalence varies considerably according to studies (11%-47.44%) mainly because there is no standardized definition of the illness. There is a possible link between PMA and premenstrual syndrome, which is a set of physical and psychic manifestations that occur in some fertile women during the same premenstrual phase. This relation has been widely studied but there are still several unknowns. PMA etiopathogeny is not known. It involves possible causes such as hormonal variations in the premenstrual phase, the coexistence of atopy, variations during the cycle in substances related to inflammation, like LTC4 leukotrienes, catecholamines, E2 and F2α prostaglandins and certain cytokines. Also considered are psychological factors related to this phase of the menstrual cycle, a high susceptibility to infection or increased bronchial hyperreactivity prior to menstruation. Yet no factor fully explains its etiology, consequently no specific treatment exists. Researchers have investigated hormones, anti-leukotrienes, prostaglandin synthesis inhibitors, diuretics, phytoestrogens and alternative therapies, but none has been shown to be effective.

Estrogen Signaling Modulates Allergic Inflammation and Contributes to Sex Differences in Asthma

Asthma is a chronic airway inflammatory disease that affects ~300 million people worldwide. It is characterized by airway constriction that leads to wheezing, coughing, and shortness of breath. The most common treatments are corticosteroids and β2-adrenergic receptor antagonists, which target inflammation and airway smooth muscle constriction, respectively. The incidence and severity of asthma is greater in women than in men, and women are more prone to develop corticosteroid-resistant or “hard-to-treat” asthma. Puberty, menstruation, pregnancy, menopause, and oral contraceptives are known to contribute to disease outcome in women, suggesting a role for estrogen and other hormones impacting allergic inflammation. Currently, the mechanisms underlying these sex differences are poorly understood, although the effect of sex hormones, such as estrogen, on allergic inflammation is gaining interest. Asthma presents as a heterogeneous disease. In typical Th2-type allergic asthma, interleukin (IL)-4 and IL-13 predominate, driving IgE production and recruitment of eosinophils into the lungs. Chronic Th2-inflammation in the lung results in structural changes and activation of multiple immune cell types, leading to a deterioration of lung function over time. Most immune cells express estrogen receptors (ERα, ERβ, or the membrane-bound G-protein-coupled ER) to varying degrees and can respond to the hormone. Together these receptors have demonstrated the capacity to regulate a spectrum of immune functions, including adhesion, migration, survival, wound healing, and antibody and cytokine production. This review will cover the current understanding of estrogen signaling in allergic inflammation and discuss how this signaling may contribute to sex differences in asthma and allergy.

Gender differences in outcomes of patients with cystic fibrosis

BACKGROUND

Cystic fibrosis (CF) is a common life-shortening genetic disease in which women have been described to have worse outcomes than males, particularly in response to respiratory infections with Pseudomonas aeruginosa. However, as advancements in therapies have improved life expectancy, this gender disparity has been challenged. The objective of this study is to examine whether a gender-based survival difference still exists in this population and determine the impact of common CF respiratory infections on outcomes in males versus females with CF.

METHODS

We conducted a retrospective cohort analysis of 32,766 patients from the United States Cystic Fibrosis Foundation Patient Registry over a 13-year period. Kaplan-Meier and Cox proportional hazards models were used to compare overall mortality and pathogen based survival rates in males and females.

RESULTS

Females demonstrated a decreased median life expectancy (36.0 years; 95% confidence interval [CI] 35.0-37.3) compared with men (38.7 years; 95% CI 37.8-39.6; p<0.001). Female gender proved to be a significant risk factor for death (hazard ratio 2.22, 95% CI 1.79-2.77), despite accounting for variables known to influence CF mortality. Women were also found to become colonized earlier with several bacteria and to have worse outcomes with common CF pathogens.

CONCLUSIONS

CF women continue to have a shortened life expectancy relative to men despite accounting for key CF-related comorbidities. Women also become colonized with certain common CF pathogens earlier than men and show a decreased life expectancy in the setting of respiratory infections. Explanations for this gender disparity are only beginning to be unraveled and further investigation into mechanisms is needed to help develop therapies that may narrow this gender gap.

Asthma is Different in Women

Gender differences in asthma incidence, prevalence and severity have been reported worldwide. After puberty, asthma becomes more prevalent and severe in women, and is highest in women with early menarche or with multiple gestations, suggesting a role for sex hormones in asthma genesis. However, the impact of sex hormones on the pathophysiology of asthma is confounded by and difficult to differentiate from age, obesity, atopy, and other gender associated environmental exposures. There are also gender discrepancies in the perception of asthma symptoms. Understanding gender differences in asthma is important to provide effective education and personalized management plans for asthmatics across the lifecourse.

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

Asthma is a heterogeneous disease with many phenotypes, and age at disease onset is an important factor in separating the phenotypes. Genetic factors, atopy, and early respiratory tract infections are well-recognized factors predisposing to childhood-onset asthma. Adult-onset asthma is more often associated with obesity, smoking, depression, or other life-style or environmental factors, even though genetic factors and respiratory tract infections may also play a role in adult-onset disease. Adult-onset asthma is characterized by absence of atopy and is often severe requiring treatment with high dose of inhaled and/or oral steroids. Variety of risk factors and nonatopic nature of adult-onset disease suggest that variety of mechanisms is involved in the disease pathogenesis and that these mechanisms differ from the pathobiology of childhood-onset asthma with prevailing Th2 airway inflammation. Recognition of the mechanisms and mediators that drive the adult-onset disease helps to develop novel strategies for the treatment. The aim of this review was to summarize the current knowledge on the pathogenesis of adult-onset asthma and to concentrate on the mechanisms and mediators involved in establishing adult-onset asthma in response to specific risk factors. We also discuss the involvement of these mechanisms in the currently recognized phenotypes of adult-onset asthma.

Sex steroid signaling: implications for lung diseases

There is increasing recognition that sex hormones (estrogen, progesterone, and testosterone) have biological and pathophysiological actions in peripheral, non-reproductive organs, including the lung. Clinically, sex differences in the incidence, morbidity and mortality of lung diseases such as asthma, chronic obstructive pulmonary disease (COPD), pulmonary fibrosis, lung cancer and pulmonary hypertension have been noted, although intrinsic sex differences vs. the roles of sex steroids are still not well-understood. Accordingly, it becomes important to ask the following questions: 1) Which sex steroids are involved? 2) How do they affect different components of the lung under normal circumstances? 3) How does sex steroid signaling change in or contribute to lung disease, and in this regard, are sex steroids detrimental or beneficial? As our understanding of sex steroid signaling in the lung improves, it is important to consider whether such information can be used to develop new therapeutic strategies to target lung diseases, perhaps in both sexes or in a sex-specific manner. In this review, we focus on the basics of sex steroid signaling, and the current state of knowledge regarding how they influence structure and function of specific lung components across the life span and in the context of some important lung diseases. We then summarize the potential for sex steroids as useful biomarkers and therapeutic targets in these lung diseases as a basis for future translational research in the area of gender and individualized medicine.

Estradiol increases mucus synthesis in bronchial epithelial cells

Airway epithelial mucus hypersecretion and mucus plugging are prominent pathologic features of chronic inflammatory conditions of the airway (e.g. asthma and cystic fibrosis) and in most of these conditions, women have worse prognosis compared with male patients. We thus investigated the effects of estradiol on mucus expression in primary normal human bronchial epithelial cells from female donors grown at an air liquid interface (ALI). Treatment with estradiol in physiological ranges for 2 weeks caused a concentration-dependent increase in the number of PAS-positive cells (confirmed to be goblet cells by MUC5AC immunostaining) in ALI cultures, and this action was attenuated by estrogen receptor beta (ER-β) antagonist. Protein microarray data showed that nuclear factor of activated T-cell (NFAT) in the nuclear fraction of NHBE cells was increased with estradiol treatment. Estradiol increased NFATc1 mRNA and protein in ALI cultures. In a human airway epithelial (1HAE₀) cell line, NFATc1 was required for the regulation of MUC5AC mRNA and protein. Estradiol also induced post-translational modification of mucins by increasing total fucose residues and fucosyltransferase (FUT-4, -5, -6) mRNA expression. Together, these data indicate a novel mechanism by which estradiol increases mucus synthesis in the human bronchial epithelium.

Progress in solving the sex hormone paradox in pulmonary hypertension

Pulmonary arterial hypertension (PAH) is a devastating and progressive disease with marked morbidity and mortality. Even though being female represents one of the most powerful risk factors for PAH, multiple questions about the underlying mechanisms remain, and two "estrogen paradoxes" in PAH exist. First, it is puzzling why estrogens have been found to be protective in various animal models of PAH, whereas PAH registries uniformly demonstrate a female susceptibility to the disease. Second, despite the pronounced tendency for the disease to develop in women, female PAH patients exhibit better survival than men. Recent mechanistic studies in classical and in novel animal models of PAH, as well as recent studies in PAH patients, have significantly advanced the field. In particular, it is now accepted that estrogen metabolism and receptor signaling, as well as estrogen interactions with key pathways in PAH development, appear to be potent disease modifiers. A better understanding of these interactions may lead to novel PAH therapies. It is the purpose of this review to 1) review sex hormone synthesis, metabolism, and receptor physiology; 2) assess the context in which sex hormones affect PAH pathogenesis; 3) provide a potential explanation for the observed estrogen paradoxes and gender differences in PAH; and 4) identify knowledge gaps and future research opportunities. Because the majority of published studies investigated 17β-estradiol and/or its metabolites, this review will primarily focus on pulmonary vascular and right ventricular effects of estrogens. Data for other sex hormones will be discussed very briefly.

[Features of asthma in women: what is the relationship with hormonal status?]

INTRODUCTION

The prevalence and control of asthma are modulated by hormonal changes in women, suggesting an influence of sex hormones on the airways.

BACKGROUND

The blood levels of both oestrogens and progesterone can modulate airway tone and inflammation. Asthma prevalence changes at puberty and the menopause, events also associated with modifications of adipose tissue and behaviour. Changes in lung function and asthma control are well documented during the menstrual cycle. However, an effect of hormone therapy on asthma control has not been demonstrated.

PERSPECTIVE

The effect of a targeted hormonal therapeutic intervention in menopausal asthma, a phenotype, which is frequently particularly severe, or in premenstrual asthma, should be evaluated by randomized trials.

CONCLUSION

Involvement of sex hormones and their cyclical variations in the characteristics of asthma in women is probable, despite lack of convincing data. However, no definitive protective or deleterious effect can be assigned. Complex interactions with adipose tissue, airways anatomy and the domestic or working environment must be taken into account to explain these differences.