Hormonal factors and respiratory health in women--a review

Review of mendelian randomization studies on age at natural menopause

Menopause marks the end of the reproductive phase of life. Based on epidemiological studies, abnormal age at natural menopause (ANM) is thought to contribute to a number of adverse outcomes, such as osteoporosis, cardiovascular disease, and cancer. However, the causality of these associations remains unclear. A powerful epidemiological method known as Mendelian randomization (MR) can be used to clarify the causality between ANM and other diseases or traits. The present review describes MR studies that included ANM as an exposure, outcome and mediator. The findings of MR analyses on ANM have revealed that higher body mass index, poor educational level, early age at menarche, early age at first live birth, early age at first sexual intercourse, and autoimmune thyroid disease appear to be involved in early ANM etiology. The etiology of late ANM appears to be influenced by higher free thyroxine 4 and methylene tetrahydrofolate reductase gene mutations. Furthermore, early ANM has been found to be causally associated with an increased risk of osteoporosis, fracture, type 2 diabetes mellitus, glycosylated hemoglobin, and the homeostasis model of insulin resistance level. In addition, late ANM has been found to be causally associated with an increased systolic blood pressure, higher risk of breast cancer, endometrial cancer, endometrioid ovarian carcinoma, lung cancer, longevity, airflow obstruction, and lower risk of Parkinson's disease. ANM is also a mediator for breast cancer caused by birth weight and childhood body size. However, due to the different instrumental variables used, some results of studies are inconsistent. Future studies with more valid genetic variants are needed for traits with discrepancies between MRs or between MR and other types of epidemiological studies.

Sex and gender in respiratory physiology

Sex is a biological concept determined at conception. Gender is a social concept. Medicine recognises sex as a biological variable and recommends including sex as a factor in clinical practice norms and as a topic of bench and clinical research. Sex plays a role in respiratory physiology according to two pathways: hormones and anatomy, with females characterised by smaller dimensions at every level of the respiratory system. Sex hormones also play specific roles in lung inflammatory processes, breathing control and in response to diseases. The literature is extremely controversial because many factors need to be considered to avoid erroneous comparisons. The main difficulty lies in creating homogeneous groups of subjects according to age, body weight, lung/airway size, fluctuations in circulating hormone levels, and exercise protocol. Because almost all of the knowledge available in physiology is based on research in males, medicine for women is therefore less evidence-based than that being applied to men. Finally, the number of transsexual people is increasing and they represent new challenges for clinicians, due to the anatomical and physiological changes that they undergo.

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

OBJECTIVES

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

DESIGN

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

PARTICIPANTS

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

OUTCOME MEASURES

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

RESULTS

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

CONCLUSIONS

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

Relationship of Nutritional Status and Spirometric Parameters in Children with Bronchial Asthma

The potential mechanisms of bronchial asthma (BA) negative modification under the influence of obesity are currently being actively studied. However, at present, the effect of nutritional status on bronchial obstruction in children with BA cannot be considered established. In this regard, the purpose of this work was to study the relationship of spirometric parameters reflecting bronchial patency with nutritional status in children with asthma.

[Woman's asthma throughout life: Towards a personalized management?]

In a woman's life, asthma can affect her in a variety of ways, with the onset of premenstrual asthma currently under-diagnosed. It is estimated that about 20% of women with asthma have premenstrual asthma, which is more common in patients with severe asthma. Women with asthma are at high risk of exacerbations and of severe asthma. Asthma is the most common chronic disease during pregnancy with potential maternal and foetal complications. Asthma medications are safe for the foetus and it is essential to continue pre-existing treatment and adapt it to the progress of asthma during the pregnancy. Sex steroids modulate the structure and function of bronchial and immune cells. Understanding their role in asthma pathogenesis is complicated by the ambivalent effects of bronchodilating and pro-inflammatory oestrogens as well as the diversity of response to their association with progesterone. Menopausal asthma is a clinical entity and is part of one of the phenotypes of severe non-allergic and low steroid-sensitive asthma. Targeted assessment of the domestic and professional environment allows optimization of asthma management.

Asthma-related health services and asthma control among women in Puerto Rico

Objectives:

This study evaluates social, behavioral, and environmental determinants to differentiate between active and inactive asthma and how predisposing, enabling, and need factors elucidate asthma-related health services and asthma control among women in Puerto Rico.

Methods:

This study analyzed secondary cross-sectional data from a subsample of 625 adult females who participated in the Asthma Call Back Survey in Puerto Rico. Logistic and multinomial regression analyses were conducted to examine associations between explanatory variables and asthma outcomes.

Results:

In total, 63% of women reported active asthma, from which 37.9% have not well controlled or very poorly controlled asthma. Women with active asthma were significantly more likely to be out of work, have middle income (US$25,000–<US$35,000), and be obese (≥30 kg/m²). Perceived need of health status is a good predictor to know the odds ratio of women to use emergency room. Women with poorly controlled asthma were significantly associated with increased units of physician urgent visits and emergency room visits.

Conclusion:

The findings confirmed significant determinants for active asthma and adds information on odds ratio for sensitive subgroups that utilize asthma-related health services in higher proportion than their counterparts. These associations suggest a development of asthma management plan targeting women to control the condition and reduce health-care utilization.

Sensitivity of airway cough-related afferents is influenced by female sex hormones

Chronic hypersensitivity cough syndrome affects mainly postmenopausal women; however, the pathogenesis of cough hypersensitivity in this demographic is not entirely understood. The role of sex hormones in cough has never been studied in detail; however, sex hormones seem to play an important role in the lung health of women. Our study was aimed to analyse the effect of female sex hormones (oestrogen - E2 and progesterone - Pg) on cough sensitivity measured by inhalation of capsaicin in follicular and luteal phases of menstrual cycle, characterized by significantly different concentrations of sex hormones. These data were compared with a matched group of women taking oral contraceptives. Cough sensitivity to capsaicin increased in luteal phase in subjects with normal menstrual cycle, and this functional change was not present in group with contraceptive pills. The cough sensitivity correlates with the Pg/E2 ratio, and relative lack of oestrogen in luteal phase is associated with higher cough sensitivity to capsaicin.

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.

Association between asthma and female sex hormones

CONTEXT AND OBJECTIVE:

The relationship between sex hormones and asthma has been evaluated in several studies. The aim of this review article was to investigate the association between asthma and female sex hormones, under different conditions (premenstrual asthma, use of oral contraceptives, menopause, hormone replacement therapy and pregnancy).

DESIGN AND SETTING:

Narrative review of the medical literature, Universidade Federal do Tocantins (UFT) and Universidade Federal de São Paulo (Unifesp).

METHODS:

We searched the CAPES journal portal, a Brazilian platform that provides access to articles in the MEDLINE, PubMed, SciELO, and LILACS databases. The following keywords were used based on Medical Subject Headings: asthma, sex hormones, women and use of oral contraceptives.

RESULTS:

The associations between sex hormones and asthma remain obscure. In adults, asthma is more common in women than in men. In addition, mortality due to asthma is significantly higher among females. The immune system is influenced by sex hormones: either because progesterone stimulates progesterone-induced blocking factor and Th2 cytokines or because contraceptives derived from progesterone and estrogen stimulate the transcription factor GATA-3.

CONCLUSIONS:

The associations between asthma and female sex hormones remain obscure. We speculate that estrogen fluctuations are responsible for asthma exacerbations that occur in women. Because of the anti-inflammatory action of estrogen, it decreases TNF-α production, interferon-γ expression and NK cell activity. We suggest that further studies that highlight the underlying physiopathological mechanisms contributing towards these interactions should be conducted.

Bisphenol A exposure alters release of immune and developmental modulators and expression of estrogen receptors in human fetal lung fibroblasts

Bisphenol A (BPA) has been shown to exert biological effects through estrogen receptor (ER)-dependent and ER-independent mechanisms. Recent studies suggest that prenatal exposure to BPA may increase the risk of childhood asthma. To investigate the underlying mechanisms in the actions of BPA, human fetal lung fibroblasts (hFLFs) were exposed to varying doses of BPA in culture for 24hr. Effects of BPA on localization and uptake of BPA, cell viability, release of immune and developmental modulators, cellular localization and expression of ERα, ERβ and G-protein coupled estrogen receptor 30 (GPR30), and effects of ERs antagonists on BPA-induced changes in endothelin-1 (ET-1) release were examined. BPA at 0.01-100μmol/L caused no changes in cell viability after 24hr of exposure. hFLFs expresses all three ERs. BPA had no effects on either cellular distribution or protein expression of ERα, however, at 100μmol/L (or 23μmol/L intracellular BPA) increased ERβ protein levels in the cytoplasmic fractions and GPR30 protein levels in the nuclear fractions. These paralleled with increased release of growth differentiation factor-15, decreased phosphorylation of nuclear factor kappa B p65 at serine 536, and decreased release of ET-1, interleukin-6, and interferon gamma-induced protein 10. ERs antagonists had no effects on BPA-induced decrease in ET-1 release. These data suggest that BPA at 100μmol/L altered the release of immune and developmental modulators in hFLFs, which may negatively influence fetal lung development, maturation, and susceptibility to environmental stressors, although the role of BPA in childhood asthma remains to be confirmed in in vivo studies.

Lower lung function associates with cessation of menstruation: UK Biobank data

Little is known about the effect of cessation of menstruation on lung function. The aims of the study were to examine the association of lung function with natural and surgical cessation of menstruation, and assess whether lower lung function is associated with earlier age at cessation of menstruation.

The study was performed in 141 076 women from the UK Biobank, who had provided acceptable and reproducible spirometry measurements and information on menstrual status. The associations of lung function (forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), spirometric restriction (FVC < lower limit of normal (LLN)), airflow obstruction (FEV1/FVC <LLN)) with cessation of menstruation and age at cessation of menstruation were assessed using regression analysis.

Women who had natural cessation of menstruation showed a lower FVC (−42 mL; 95% CI −53– −30) and FEV1 (−34 mL; 95% CI −43– −24) and higher risk of spirometric restriction (adjusted odds ratio 1.27; 95% CI 1.18–1.37) than women still menstruating. These associations were stronger in women who had had a hysterectomy and/or oophorectomy. The earlier the natural cessation of menstruation, the lower the lung function. There was no clear association of lung function with age at hysterectomy and/or oophorectomy. Airflow obstruction was not associated with cessation of menstruation.

Lower lung function associates with cessation of menstruation, especially if it occurs early in life.

Gender differences in adult-onset asthma: results from the Swiss SAPALDIA cohort study

A higher incidence of asthma is reported in women compared with men, but evidence in later adulthood is limited. We aimed to determine the 20-year cumulative incidence of adult asthma in Switzerland and its relation to sex, taking into account age and allergic sensitisation.We assessed incidence of self-report of doctor-diagnosed asthma between 1991/1992 and 2010/2011 in 5128 subjects without asthma, aged 18-60 years at baseline. The age-related probability of asthma onset was analysed by logistic regression adjusting for potential confounders and stratified by sex and allergic sensitisation at baseline.Over 20 years, 128 (5.1%) men and 198 (7.5%) women newly reported doctor-diagnosed asthma. The adjusted odds ratio for female sex was 1.99 (95% CI 1.54-2.57) overall, 3.21 (95% CI 2.12-4.85) among nonsensitised subjects, and 1.43 (95% CI 1.02-2.02) in sensitised subjects. The probability of asthma onset decreased with increasing baseline age in women but not in men. The higher probability of new asthma in sensitised compared with nonsensitised men was unrelated to age, whereas in women it decreased with age.Asthma incidence was higher in women than in men but decreased with increasing age. The female predominance was considerably stronger in nonsensitised adults compared with those with allergic sensitisation.

Age at menarche and risk of asthma: systematic review and meta-analysis

BACKGROUND

Several studies have suggested a relationship between the age at menarche and risk of asthma development.

OBJECTIVE

To conduct a systematic review and meta-analysis of the relationship between the age at menarche and the risk of asthma.

METHODS

This systematic review and meta-analysis was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA). A pre specified literature search strategy was used to identify studies of potential relevance and independent reviews were carried out by two authors. Raw data was pooled using the software package RevMan to calculate summary odds ratios. The risk of publication bias was assessed graphically by using a funnel plot and the robustness of the overall estimate obtained was assessed by using sensitivity analyses.

RESULTS

The searches identified 61 potentially relevant articles of which seven articles, with a total of 22,859 subjects, matched the inclusion criteria for the meta-analysis. Pooling of the seven studies showed that girls with early menarche (<12 years) had an increased risk of asthma relative to girls with late menarche; random effects odds ratio = 1.37 (1.15-1.64), (p = 0.0005). Substantial heterogeneity was revealed (I(2) = 55%). Sensitivity analysis showed that the risk estimate was not markedly changed when excluding any of the studies. The funnel plot did not indicate publication bias.

CONCLUSIONS

Early menarche appears to be associated with increased risk of asthma. Hormonal, immunological, genetic and environmental factors may act in a developmental context to explain this relationship. Future studies are warranted to further determine the mechanisms responsible for this observation.

Estrogen replacement therapy and asthma

A growing body of clinical and experimental evidence indicates that female sex hormones, particularly estrogen, have significant effects on normal airway function as well as on respiratory disorders, such as asthma. These effects are very complex and are exerted at several levels, directly on airway reactivity or indirectly through regulation of the immune and inflammatory responses in the lung. They can have relevant clinical implications not only according to the phases of the reproductive life in women, but also in relation to the therapeutical administration of estrogen, as in the case of menopausal hormone therapy. Clinical evidence suggests that administration of estrogen to menopausal women is associated with increased rates of newly diagnosed asthma. Conversely, functional studies show that estrogen can improve objective indexes of respiratory functionality.

Anatomy of female puberty: The clinical relevance of developmental changes in the reproductive system

Puberty is the period of biologic transition from childhood to adulthood. The changes that occur at this time are related to the increasing concentrations of sex steroid hormones. In females, most pubertal changes are caused by estrogen stimulation that results from the onset of central puberty. Significant development occurs in the organs of the female reproductive system and results in anatomic changes that characterize reproductive maturity. Adrenal and ovarian androgens also increase during puberty, affecting change that includes the promotion of certain secondary sex characteristics. The ability to recognize normal pubertal anatomy and distinguish between estrogen and androgen effects is important in the ability to diagnose and treat disorders of sex development, precocious puberty, pubertal delay, and menstrual irregularities in children and adolescents. An understanding of this developmental process can also help clinicians identify and treat reproductive pathology in adults and across all female life stages.

Association of Age at Menarche and Menstrual Characteristics with Adult Onset Asthma among Reproductive Age Women

BACKGROUND

Observations of increasing asthma incidence, decreasing age at menarche, and common risk factors have led investigators to hypothesize potential associations of age at menarche or menstrual characteristics with incidence of adult onset asthma. We evaluated these associations among reproductive age women.

METHODS

Study participants were selected from among women enrolled in a pregnancy cohort study. Information on age at menarche, menstrual characteristics, and history of asthma was collected using interviewer-administered questionnaires. Adult onset asthma was defined as asthma first diagnosed after onset of menarche. Women who had no information on asthma and menstrual history and those who were diagnosed with asthma before menarche were excluded. A total of 3,461 women comprised the analytic population. Logistic regression was used to estimate adjusted relative risk (aRR) and 95% confidence intervals (95% CI) relating age at menarche and menstrual characteristics with adult onset asthma.

RESULTS

Mean age at menarche was 12.8 years (standard deviation=1.46). Among study participants, 7.5% were diagnosed with asthma after the onset of menarche. After controlling for potential confounders (age, race, body mass index, and socio-economic status), women who had early menarche (<12 years old) had 60% higher risk of being diagnosed with adult onset asthma as compared with women who did not have early menarche (≥ 12 years old) (aRR= 1.59, 95% CI 1.19 - 2.13). Menstrual irregularities or abnormal (short or long) cycle length were not associated with risk of adult onset asthma. In addition, no significant interaction was observed between age at menarche or menstrual characteristics with body mass index or physical activity (in adolescence) in relation to adult onset asthma.

CONCLUSION

Early menarche is associated with a higher risk of developing adult onset asthma among reproductive age women. Mechanisms for this association are potential areas of future research.

[Exacerbations of asthma--precipitating factors: drugs]

Asthmatic exacerbations are sometimes triggered by medications, primarily the non-steroidal anti-inflammatory agents (NSAIDS) and beta-blockers. Asthma attacks induced by NSAIDS occur rapidly and can be severe. Widal syndrome is a specific disease entity whose physiopathology remains incompletely explained. Asthma is characteristically severe and steroid dependent; desensitisation with aspirin has been proposed, but this remains controversial. Beta-blockers are contra-indicated in asthma; the β1 "cardioselectivity" of some agents is not absolute, disappearing at high doses and the "partial agonists" are not better tolerated. However, certain authors have called into question the harmful effect of beta-blockade in moderate and stable asthma. More studies are needed, but the current data suggest that in some cases beta-blockers may be safe but their use requires close supervision. Other molecules can pose problems in asthmatics (dipyridamole, synthetic sex hormones and certain excipients). On the whole, there has been little innovation concerning the hazard that drugs can pose for some asthmatics. The task for the future will be to specify the physiopathology of Widal syndrome, and to clarify the categories of patients in whom beta-blockers can be safely employed as the public health consequences of cardiovascular pathologies make this an important issue for lung specialists.