Menopause, lung function and obstructive lung disease outcomes: a systematic review

Association between viral hepatitis and metabolic syndrome in lung function impairment: A Taiwan community-based study

OBJECTIVES

Metabolic syndrome (MetS) and hepatitis C virus (HCV) are associated with a higher risk of impaired pulmonary function (iPF). This study aimed to investigate the relationships among MetS, iPF, and viral hepatitis.

METHODS

This community-based study enrolled participants undergoing annual health check-ups in southern Taiwan between March and December 2019. We performed multivariable logistic regression analyses adjusted for demographics and characteristics to identify the factors associated with iPF.

RESULTS

A total of 2337 participants completed examinations, of whom 928 (39.7%) had iPF. The participants with iPF were elderly (68.8  ±  12.8 years old) and predominately female (63%). MetS increased the risk of iPF (odds ratio (OR) 1.51, 95% confidence interval (CI) 1.27-1.81, p < 0.001). Beyond age (OR 1.03, 95% CI 1.02-1.04) and smoking (OR 1.309, 95% CI 1.004-1.705), female sex (OR 0.74, 95% CI 0.59-0.93) and high education level (OR 0.96, 95% CI 0.94-0.98, p < 0.001) protected against iPF. HCV was not significantly associated with iPF (OR 1.17, 95% CI 0.90-1.52, p  =  0.235) in multivariable analysis. MetS was associated with a higher risk of iPF in the non-HBV/HCV group (OR 1.86, 95% CI 1.54-2.26) and HBV alone group (OR 3.44, 95% CI 1.89-6.28), but not in the HCV alone group (OR 1.02, 95% CI 0.64-1.62).

DISCUSSION

MetS was an independent predictor of iPF, especially the restrictive type, and had different effects in the HBV/non-viral hepatitis and HCV groups. Female sex and education were inversely associated with iPF.

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.

Effects of changing reference values on the interpretation of spirometry for rubber workers

Introduction

The National Health and Nutrition Assessment Survey (NHANES) is being adopted for interpreting spirometry in occupational examinations. Rubber workers have an elevated risk of respiratory health issues due to industrial exposure, and changes in the equations would affect spirometry monitoring programs.

Objective

To determine the differences in the use of the Knudson and NHANES III equations in nonsmoking workers in the rubber industry.

Method

A cross-sectional study was conducted with 75 nonsmoking workers with occupational exposure to rubber for at least two years. The factory had engineered protection controls and provided respiratory protection to the workers. Spirometry was conducted according to Spirometry Testing in Occupational Health Programs and Standardization of Spirometry: American Thoracic Society/European Respiratory Society.

Result

Spirometric prediction differences were present in the restrictive pattern assessment based on forced vital capacity (FVC), in which three individuals (4%) classified as normal according to Knudson presented restrictive disease according to NHANES III; only in the record of one participant was there restrictive disease using both equations. There was an 8% discrepancy for small airway obstruction in which six workers classified as normal using NHANES III were classified as diseased (FEF 25-75 <50%) using the Knudson equation.

Conclusion

In the respiratory examination of workers exposed to rubber, the NHANES III equation is better able to detect restrictive diseases than is the Knudson equation; however, the Knudson equation is more sensitive to obstructive patterns.

Sexual dimorphism in chronic respiratory diseases

Sex differences in susceptibility, severity, and progression are prevalent for various diseases in multiple organ systems. This phenomenon is particularly apparent in respiratory diseases. Asthma demonstrates an age-dependent pattern of sexual dimorphism. However, marked differences between males and females exist in other pervasive conditions such as chronic obstructive pulmonary disease (COPD) and lung cancer. The sex hormones estrogen and testosterone are commonly considered the primary factors causing sexual dimorphism in disease. However, how they contribute to differences in disease onset between males and females remains undefined. The sex chromosomes are an under-investigated fundamental form of sexual dimorphism. Recent studies highlight key X and Y-chromosome-linked genes that regulate vital cell processes and can contribute to disease-relevant mechanisms. This review summarises patterns of sex differences in asthma, COPD and lung cancer, highlighting physiological mechanisms causing the observed dimorphism. We also describe the role of the sex hormones and present candidate genes on the sex chromosomes as potential factors contributing to sexual dimorphism in disease.

Triglyceride-Glucose Index is a Risk Marker of Incident COPD Events in Women

Purpose

The triglyceride-glucose index (TyG index) is a marker of insulin resistance and metabolic dysfunction and has the advantage of being universally available. Although recent evidence suggests the TyG index has relevance to respiratory health, there have been no prospective studies assessing its value as a biomarker for chronic lung diseases. We aim to assess the TyG index as a potential risk marker for future incident COPD events in the general population.

Patients and Methods

Baseline TyG index was assessed in 28,282 middle-aged men and women without previous history of chronic obstructive pulmonary disease (COPD) from the Malmö Preventive Project (men between 1974 and 1982 and women between 1982 and 1992). All subjects were followed up prospectively, and Cox proportional hazards regression was used to assess incident COPD events according to quartiles of TyG index.

Results

After an average of 31 years of follow-up, TyG index was a strong predictor of future COPD events even after adjusting for potential confounders (Q4 (highest TyG index) HR (95% CI): 1.21 (1.09–1.35) vs Q1 (reference), p-trend <0.001). After stratifying by sex, the results remained statistically significant in women only (Q4 vs Q1 HR 1.72 (1.41–2.09)). Additionally, the risk remained significant in a cohort of life-long never smokers (Q4 vs Q1 HR 1.47 (1.08–2.01)).

Conclusion

A raised TyG index is a novel risk marker of future incident COPD events in women. Insulin resistance as reflected by the TyG index can precede the development of obstructive lung disease and as such may be an easily measurable and useful predictor of COPD in women.

Sex Disparities in Asthma Development and Clinical Outcomes: Implications for Treatment Strategies

A gender-related disparity exists in asthma morbidity and mortality, which shifts at around puberty from a male predominance to a female predominance. This is clinically reflected in the fact that asthma that occurs in childhood (childhood-onset asthma) mainly affects boys, and that asthma that occurs in adulthood (adult-onset asthma) mainly affects women. Adult-onset asthma is often non-atopic, more severe, and associated with a poorer prognosis, thus posing a marked burden to women’s health and healthcare system. Many factors have been indicated to explain this gender-related disparity, including sociocultural and environmental factors as well as biological sex differences (genetic, pulmonary and immunological factors). It has long been suggested that sex hormones may be implicated in at least these biological sex differences. Overall, the evidence remains equivocal for the role of most sex hormones in asthma pathogenesis and clinical outcomes. Well-designed randomized clinical trials are required assessing the potential preventive or therapeutic effects of hormonal contraceptives on asthma in women, thereby helping to advance the evidence to inform future practice guidelines. The mechanisms underlying the role of sex hormones in asthma are complex, and our understanding is not yet complete. Additional mechanistic studies elucidating sex hormone signaling pathways and their interactions involved in the pathogenesis and clinical manifestations of asthma will help to identify potential sex hormone-driven asthma endotypes and novel therapeutic targets, providing the basis for a more personalized asthma management strategy.

Noninvasively measured radial pressure wave analysis provides insight into cardiovascular changes during pregnancy and menopause

OBJECTIVE

Pregnancy and menopause are significant life events associated with major changes in female hormone levels and changes in cardiovascular health. The role of estrogen in influencing cardiovascular risk is an ongoing research topic. Many studies have provided evidence that radial pressure wave characteristics are an important indicator to consistently and independently predict cardiovascular events. The aim of this study was to investigate if radial pressure wave analysis provided statistical insights into the physiological variations due to pregnancy and menopause. Furthermore, the study investigated how these variations could serve as an indicator for cardiovascular risks. As the radial pulse measurement is non-invasive and speedy, it may be helpful in evaluating cardiovascular changes and risk during these transitions.

MATERIALS AND METHOD

A total of 702 randomly selected female subjects (90 pregnant and 97 post-menopausal), aged 20-59, enrolled in the study. The visit measured the subject's hemodynamic parameters including heart rate, systolic blood pressure (SBP), diastolic blood pressure (DBP) and radial pressure waves. SBP and DBP were evaluated by an automatic blood pressure monitor. Radial pressure wave data were continuously recorded for 12-s using a TD01C pulse measuring instrument. Spectrum analysis of the radial pressure wave was performed to evaluate the first five harmonic components (C1-C5).

RESULTS

A comparison of pregnant women to non-pregnant women showed C3 and C5 were lower. Heart rate C2 and C4 were higher in pregnant women. A comparison of women pre-menopausal and post-menopausal showed no significant difference in SBP or DBP. Menopause significantly changed the C1 and C4 radial pressure wave harmonics. An increase in C1 and a decrease in C4 were observed.

CONCLUSION AND DISCUSSION

This study provided further clinical evidence to support the hemodynamic model that describes the cardiovascular changes and risks related to the harmonic components of the pulse spectrum. Beyond blood pressure, the effects of menopause on the radial pressure wave, especially on hemodynamic index C4, independent of age and BMI, may explain increased post-menopausal cardiovascular risk. This and past studies collectively suggest that radial pressure wave components may be an indicator of a female body's ability to supply oxygen and nutrients. Harmonic analysis of the radial pressure wave may provide additional insights into the underlying mechanism of the cardiovascular changes over the lifespan of a woman.

The Impact of the Synergistic Effect of Temperature and Air Pollutants on Chronic Lung Diseases in Subtropical Taiwan

Previous studies have suggested an association between air pollution and lung disease. However, few studies have explored the relationship between chronic lung diseases classified by lung function and environmental parameters. This study aimed to comprehensively investigate the relationship between chronic lung diseases, air pollution, meteorological factors, and anthropometric indices. We conducted a cross-sectional study using the Taiwan Biobank and the Taiwan Air Quality Monitoring Database. A total of 2889 participants were included. We found a V/U-shaped relationship between temperature and air pollutants, with significant effects at both high and low temperatures. In addition, at lower temperatures (<24.6 °C), air pollutants including carbon monoxide (CO) (adjusted OR (aOR):1.78/Log 1 ppb, 95% CI 0.98–3.25; aOR:5.35/Log 1 ppb, 95% CI 2.88–9.94), nitrogen monoxide (NO) (aOR:1.05/ppm, 95% CI 1.01–1.09; aOR:1.11/ppm, 95% CI 1.07–1.15), nitrogen oxides (NO_x) (aOR:1.02/ppm, 95% CI 1.00–1.05; aOR:1.06/ppm, 95% CI 1.04–1.08), and sulfur dioxide (SO₂) (aOR:1.29/ppm, 95% CI 1.01–1.65; aOR:1.77/ppm, 95% CI 1.36–2.30) were associated with restrictive and mixed lung diseases, respectively. Exposure to CO, NO, NO₂, NO_x and SO₂ significantly affected obstructive and mixed lung disease in southern Taiwan. In conclusion, temperature and air pollution should be considered together when evaluating the impact on chronic lung diseases.

The impacts of parity on spirometric parameters: a systematic review

Introduction: The relationship between parity and health outcomes has been debated in the scientific literature in terms of 'selection-pressure'. However, no previous review has raised the impacts of parity on spirometric parameters. This Systematic Review aimed to review the impacts of parity on spirometric parameters.Areas covered: PubMed and Scopus were searched on October 1^st, 2020, using the combination of the following two medical subject headings: 'Parity' and 'Respiratory Function Tests'. Only original articles published in English/French were retained. Ten studies investigated the impacts of parity on spirometric parameters: six included healthy females, three involved unhealthy females [chronic obstructive pulmonary disease, defect in protease inhibitor, and some other conditions] and one included a mixed population of healthy/unhealthy females. The studies reported conflicting results: no impact, positive impact (multiparity is associated with larger forced-expiratory-volume in one second, forced- and slow- vital-capacity, and inspiratory-capacity), or negative impact (multiparous females has lower bronchial flows, higher static volumes, an accelerated lung-aging, a tendency to an obstructive-ventilatory-defect and/or to lung-hyperinflation, and increased protease inhibitor levels).Expert opinion: The ten studies presented some limitations that made data interpretation relatively difficult. Future research to identify the 'real' impact of parity on spirometric parameters are therefore encouraged.

Age at natural menopause and development of chronic conditions and multimorbidity: results from an Australian prospective cohort

STUDY QUESTION

Is age at natural menopause (ANM) associated with the development of multiple chronic conditions (multimorbidity) in postmenopausal life?

SUMMARY ANSWER

Women with premature menopause experience increased odds of developing individual chronic conditions and multimorbidity.

WHAT IS KNOWN ALREADY

ANM is considered as a marker of age-related morbidity and mortality in postmenopausal life. Multimorbidity affects more than 60% of older women and has been recognized as the most common 'chronic condition'. Few studies have examined the association between ANM and the development of multimorbidity.

STUDY DESIGN, SIZE, DURATION

A prospective national cohort study of 11 258 Australian women, aged 45-50 years in 1996. Women were followed from 1996 to 2016.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Information about ANM and 11 chronic conditions (diabetes, hypertension, heart disease, stroke, arthritis, osteoporosis, asthma, chronic obstructive pulmonary disease, depression, anxiety and breast cancer) were estimated approximately every 3 years. Multimorbidity is defined as 2 or more of these 11 conditions. Generalized estimating equations were used to link the categorical ANM with individual chronic conditions and multimorbidity.

MAIN RESULTS AND THE ROLE OF CHANCE

Among 5107 women reporting ANM, 2.3% experienced premature menopause (≤40 years) and 55.1% developed multimorbidity. Compared with women who experienced menopause at age 50-51 years, women with premature menopause had twice the odds of experiencing multimorbidity by age 60 (OR = 1.98, 95% CI 1.31 to 2.98) and three times the odds of developing multimorbidity in their 60s (OR = 3.03, 95% CI 1.62 to 5.64). Women with premature menopause also experienced higher incidence of most individual chronic conditions.

LIMITATIONS, REASONS FOR CAUTION

The main limitation of this study was the use of self-reported data, but with repeated assessments from prospective study design and the validity of most of the chronic conditions from hospital data, the potential for non-differential misclassification is minimized.

WIDE IMPLICATIONS OF THE FINDINGS

To our knowledge, this is the first study to assess the association of premature menopause and development of multimorbidity in a larger national cohort of mid-aged women. Health professionals should consider comprehensive screening and assessment of risk factors for multimorbidity when treating women who experienced premature menopause.

STUDY FUNDING/COMPETING INTEREST(S)

The Australian Longitudinal Study on Women's Health was supported by the Australian Government Department of Health. X.X. is funded by an International Postgraduate Research Scholarship from the Australian government and a UQ Centennial Scholarship from The University of Queensland. G.D.M. is supported by the National Health and Medical Research Council Principal Research Fellowship (APP1121844). None of the authors has any conflicts of interest to declare.

Stages of menopause and abnormal lung function: a cross-sectional study of middle-aged women

OBJECTIVE

Whether hormonal changes during menopausal transition postmenopause stages influence pulmonary function is not clearly understood. We evaluated the association between each stage of menopause and the prevalence of abnormal lung function in healthy middle-aged women. We hypothesized that the prevalence of abnormal lung function would increase from the late menopausal transition stage during menopausal transition postmenopause stages.

METHODS

The study population included women 40 to 65 years of age who underwent comprehensive health screening examination at the Kangbuk Samsung Hospital Total Healthcare Centers from January 2015 to December 2017. Stages of menopause (premenopausal, early menopausal transition, late menopausal transition, and postmenopausal) were defined using the 2011 Stages of Reproductive Aging Workshop (STRAW + 10) criteria. Abnormal lung function was defined based on spirometry as forced expiratory volume in 1 second/forced vital capacity less than70% or forced vital capacity less than 80% predicted. Prevalence ratios (PRs) for abnormal lung function by stages of menopause were estimated from logistic regression models adjusted for age, anthropometric measurements, lifestyle factors, medical history, lipid and inflammatory biomarkers, and reproductive factors.

RESULTS

Among 43,822 participants, there were 4,615 participants (10.5%) with restrictive ventilatory disorder and 653 participants (1.5%) with obstructive ventilatory disorder. The fully adjusted PRs (95% confidence interval) for abnormal ventilatory disorder comparing early menopausal transition, late menopausal transition, and postmenopausal stage to premenopausal stage were 1.01 (0.94-1.08), 1.13 (1.03-1.22), and 1.10 (0.98-1.22), respectively. The fully adjusted PRs for restrictive ventilatory disorder comparing early menopausal transition, late menopausal transition, and postmenopausal stages to premenopausal stage were 1.02 (0.94-1.11), 1.18 (1.06-1.30), and 1.15 (1.00-1.31), respectively. There was, however, no clear association between stages of menopause and obstructive ventilatory disorder.

CONCLUSIONS

In this large study of middle-aged women, the fully adjusted prevalence of abnormal lung function, particularly that of restrictive ventilatory disorder, was higher in women in late menopausal transition and menopausal stages compared to women in premenopausal stage.

Early Age at Natural Menopause Is Related to Lower Post-Bronchodilator Lung Function. A Longitudinal Population-based Study

Rationale: Poor lung function, a significant predictor of mortality, has been observed in postmenopausal women compared with those still menstruating. Menopausal age is a risk factor for several adverse health outcomes, but little evidence exists on the impact of menopausal age on lung function impairments, especially regarding post-bronchodilator lung function measures.Objectives: To investigate the association between age at menopause and pre- and post-bronchodilator lung function outcomes.Methods: During the sixth-decade follow-up of the Tasmanian Longitudinal Health Study cohort (mean age, 53 yr), information was collected on most recent menstrual period and menopausal status. Lung function was measured at age 7 years and again at 53 years. Multiple linear regression was performed to determine the association between age at menopause and pre- and post-bronchodilator spirometry, controlling for early and adult life confounders.Results: Women reporting an early age at natural menopause (<45 yr) had lower post-bronchodilator forced expiratory volume in 1 second (-168 ml; 95% confidence interval, -273 to -63) and lower forced vital capacity (-186 ml; 95% confidence interval, -302 to -70) than postmenopausal women who experienced menopause at a later age (≥45 yr). No association was observed with forced expiratory volume in 1 second/forced vital capacity ratio. Adjustment for early-life confounders strengthened these associations.Conclusions: This study provides new evidence that early menopause is associated with reduced lung function that is suggestive of restriction, but not obstruction, even after adjustment for early-life confounders. Given the important link between poor lung function and mortality, clinicians should be aware of the risk of diminished lung function in postmenopausal women who experience menopause at an early age.

Female reproductive history in relation to chronic obstructive pulmonary disease and lung function in UK biobank: a prospective population-based cohort study

OBJECTIVES

Sex differences in respiratory physiology and predilection for developing chronic obstructive pulmonary disease (COPD) have been documented, suggesting that female sex hormones may influence pathogenesis. We investigated whether aspects of female reproductive health might play a role in risk of COPD among women.

DESIGN

Population-based prospective cohort study.

SETTING

UK Biobank recruited across 22 centres in the UK between 2006 to 2010.

PRIMARY AND SECONDARY OUTCOMES MEASURES

We examined a range of female reproductive health indicators in relation to risk of COPD-related hospitalisation/death (n=271 271) using Cox proportional hazards regression; and lung function (n=273 441) using linear regression.

RESULTS

Parity >3 was associated with greater risk of COPD-related hospitalisation/death (adjusted HR 1.45; 95% CI: 1.16 to 1.82) and lower forced expiratory volume at 1 second/forced vital capacity ratio (FEV₁/FVC) (adjusted mean difference -0.06; 95% CI: -0.07 to 0.04). Any oral contraception use was associated with lower risk of COPD-related hospitalisation/death (adjusted HR 0.85; 95% CI: 0.74 to 0.97) and greater FEV₁/FVC (adjusted mean difference 0.01; 95% CI: 0.003 to 0.03). Late menarche (age >15) and early menopause (age <47) were also associated with greater risk of COPD-related hospitalisation/death (but not lung function), while endometriosis was associated with greater FEV₁/FVC (not COPD-related hospitalisation/death). Early menarche (age <12 years) was associated with lower FEV₁/FVC (but not COPD hospitalisation/death). Associations with polycystic ovary syndrome (PCOS) or ovarian cysts, any hormone replacement therapy (HRT) use, hysterectomy-alone and both hysterectomy and bilateral oophorectomy were in opposing directions for COPD-related hospitalisation/death (greater risk) and FEV₁/FVC (positive association).

CONCLUSIONS

Multiple female reproductive health indicators across the life course are associated with COPD-related hospitalisation/death and lung function. Further studies are necessary to understand the opposing associations of PCOS/ovarian cysts, HRT and hysterectomy with COPD and objective measures of airway obstruction.

Risk of asthma onset after natural and surgical menopause: Results from the French E3N cohort

BACKGROUND

The gender switch in asthma incidence around puberty has been put forward to suggest a role of sex hormones in asthma. However, there are limited and inconsistent findings on change in asthma incidence with menopause. We aimed to investigate the associations between menopause and asthma incidence, and interactions with overweight/obesity.

METHODS

Asthma incidence was assessed in 67,872 women free of asthma at baseline (aged 41-68 years) and regularly followed up as a part of the French E3N cohort. Adjusted hazard ratios (aHR) were derived from Cox models considering age as the time-scale, menopausal status as a time-varying covariate and taking into account menopausal treatment.

RESULTS

During 843,243 person-years of follow-up, 1205 new-onset asthma cases were identified. Compared with pre-menopause, surgical menopause was associated with an increased risk of asthma onset (aHR = 1.33 [95%CI 1.01-1.75]) but no association was observed for natural menopause (aHR = 1.05 [0.84-1.32]). In women with natural menopause, a further analysis separating the transition through menopause and the later post-menopausal period did not show any change in asthma incidence with menopause in the total sample or in normal-weight women alone. However, in overweight/obese women, peri-menopausal and post-menopausal women had an increased risk of developing asthma compared with pre-menopausal women of the same age (aHR = 1.91 [1.00-3.66] and aHR = 2.08 [1.07-4.06] respectively).

CONCLUSION

Surgical menopause was associated with an increased risk of asthma onset. For natural menopause, no change in asthma incidence was observed in normal-weight women. However, overweight/obese women had an increased risk of developing asthma after natural menopause.