Chronic Obstructive Pulmonary Disease in Women: A Biologically Focused Review with a Systematic Search Strategy

Management Reality of Female Patients with COPD: A Multicenter Cross-Sectional CAP Study in Japan

Background

Reports from Europe and North America suggest that female chronic obstructive pulmonary disease (COPD) patients have a higher symptom burden and mortality than male patients. However, little is known about the management reality of female patients with COPD in Japan.

Patients and Methods

We compared the clinical characteristics of female COPD patients with those of male using the cohort of the COPD Assessment in Practice study, which is a cross-sectional multicenter observational study.

Results

Of the 1168 patients, 133 (11.4%) were female. A history of never smoking was higher in females than males (p<0.01). Although there was no difference in age or forced expiratory volume in one second (FEV1) % predicted between the groups, modified medical research council dyspnea scale (mMRC) and number of frequent exacerbators were higher in females (mMRC≥2: p<0.01; number of exacerbations≥2: p=0.011). The mean forced vital capacity and FEV1 values in females were lower than those in males (p<0.0001 and p<0.0001, respectively). Females were more likely to use long-term oxygen therapy and inhaled corticosteroids than males (p=0.016 and p<0.01, respectively). The prevalence of the Global Initiative for Chronic Obstructive Lung Disease (GOLD) groups B, C, D (ABCD GOLD 2017 classification), and E (ABE GOLD 2023 classification) was higher in females than in males.

Conclusion

The disease burden of female patients with COPD is higher than that of male patients in Japan, suggesting the importance of interventions considering female-dominant features such as lower absolute FVC and FEV1, respiratory failure, and asthma-like conditions.

Sex related differences in muscle health and metabolism in chronic obstructive pulmonary disease

BACKGROUND & AIMS

Sex differences in muscle function and mass, dyspnea, and clinical outcomes have been observed in patients with Chronic Obstructive Pulmonary Disease (COPD) despite a similar level of airflow obstruction. Protein and amino acid metabolism is altered in COPD, however, it remains unclear whether a difference in metabolic signature exists between males and females with COPD that may explain the observed differences in muscle health and clinical outcomes.

METHODS

In 234 moderate to severe COPD patients (males/females: 113/121) and 182 healthy controls (males/females: 77/105), we assessed, besides presence of comorbidities and clinical features, muscle function by handgrip and leg dynamometry, and body composition by dual-energy x-ray absorptiometry. In the postabsorptive state, a mixture of 18 stable isotopes of amino acids was administered by pulse and arterialized blood was sampled for 2 h. Amino acid concentrations and enrichments were analyzed by LC-MS/MS to calculate whole body (net) protein breakdown (WBnetPB) and whole body production (WBP) rates (μmol/hour) of the amino acids playing a known role in muscle health. Statistics was done by ANCOVA to examine the effects of sex, COPD, and sex-by-COPD interaction with as covariates age and lean mass. Significance was set as p < 0.05.

RESULTS

Lung function was comparable between males and females with COPD. Being a female and presence of COPD were independently associated with lower appendicular lean mass, muscle strength, and WBnetPB (p < 0.05). Being a male was associated with higher visceral adipose tissue, C-reactive protein (CRP) (p < 0.05), and higher prevalence of heart failure and obstructive sleep apnea. Sex-by-COPD interactions were found indicating lower fat mass (p = 0.0005) and WBPs of phenylalanine (measure of whole body protein turnover) and essential amino acids (p < 0.05), particularly in COPD females. Higher visceral adipose tissue (p = 0.025), CRP (p < 0.0001), and WBP of tau-methylhistidine (p = 0.010) (reflecting enhanced myofibrillar protein breakdown) were observed in COPD males.

CONCLUSIONS

Presence of sex specific changes in protein and amino acid metabolism and cardiometabolic health in COPD need to be considered when designing treatment regimens to restore muscle health in males and females with COPD.

CLINICAL TRIAL REGISTRY

www.

CLINICALTRIALS

gov, NCT01787682, NCT01624792, NCT02157844, NCT02065141, NCT02770092, NCT02780219, NCT03327181, NCT03796455, NCT01173354, NCT01154400.

Chronic obstructive pulmonary disease mortality trends in Spain, 1980-2020

OBJECTIVES

In Spain, there has been a recent increase in the mortality rate for chronic obstructive pulmonary disease (COPD) in younger women. This study aimed to analyze trends in the COPD mortality rate in Spain from 1980 to 2020, evaluating any differences between genders and age groups.

METHODS

Death certificates and mid-year population data were obtained from the Spanish National Institute of Statistics. For both genders, age group-specific and standardized (overall and truncated) rates were calculated by the direct method using the world standard population. The data were analyzed using the joinpoint regression method.

RESULTS

In both men and women, the number of COPD deaths increased from 1980 to 1999 (average annual increase of 7% in men and 4% in women), while from 1999 onwards, deaths decreased by -1.0% per year in both genders. In women, there was a significant final period of increase in the 55-59 to 70-74 age groups and a slowing of the decline in the over 75 age group. Additionally, an increase in mortality for the truncated rates was observed for women between 2006 and 2020. In men under 70 years of age, there was an initial period in which death rates remained stable or significantly increased, followed by a period in which they decreased significantly.

CONCLUSIONS

Our study shows age and gender differences in COPD mortality trends in Spain. Although the data show a downward trend, we have identified a worrying increase in the truncated rates in women for the last few years.

Gender dimorphism in IgA subclasses in T2-high asthma

Immunoglobulin A (Chan in J Allergy Clin Immunol 134:1394-14014e4, 2014), the second most abundant immunoglobulin in serum, plays an important role in mucosal homeostasis. In human serum, there are two subclasses of IgA, IgA1 (≅ 90%) and IgA2 (≅ 10%), transcribed from two distinct heavy chain constant regions. This study evaluated the serum concentrations of total IgA, IgA1, and IgA2, and total IgG, IgG1, IgG2, IgG3, and IgG4 in T2-high asthmatics compared to healthy controls and the presence of gender-related variations of immunoglobulins. Total IgA levels were increased in asthmatics compared to controls. Even more marked was the increase in total IgA in male asthmatics compared to healthy male donors. IgA1 were increased only in male, but not in female asthmatics, compared to controls. Concentrations of IgG2, but not IgG1, IgG3, and IgG4, were reduced in asthmatics compared to controls. IgG4 levels were reduced in female compared to male asthmatics. In female asthmatics, IgA and IgA1 levels were increased in postmenopause compared to premenopause. IgA concentrations were augmented in mild, but not severe asthmatics. A positive correlation was found between IgA levels and the age of patients and an inverse correlation between serum concentrations of IgA2 and IgE in asthmatics. A positive correlation between total IgA or IgA2 and IgG2 was found in asthmatics. These results highlight a gender dimorphism in IgA subclasses in male and female T2-high asthmatics. More adequate consideration of immunological gender disparity in asthma may open new opportunities in personalized medicine by optimizing diagnosis and targeted therapy.

Impact of Sex on Circulating Leukocytes Composition in COPD Patients

Purpose

Chronic obstructive pulmonary disease is characterized by chronic inflammatory response both at the lung site and at the systemic level. Abnormalities in circulating leukocytes have been reported to occur in COPD patients and have been often shown to correlate with the decline in lung function. COPD affects men and women at a virtually comparable rate, even though distinct sex specific symptoms, progression and therapeutic implications have been described. Nonetheless, these sex-associated differences have not been analyzed in terms of circulating leukocytes. To assess the impact of sex on the changes of circulating immune cells in COPD patients.

Patients and Methods

Blood samples were collected from 50 COPD patients (31 males, 19 females) and 63 age and sex-matched controls (35 males, 28 females) enrolled in this pilot study. Complete blood cell count and multi-parametric flow cytometry analysis were performed to characterize the leukocyte populations and subsets.

Results

Male COPD patients are distinguished from controls by a significant increase in white blood cell counts, neutrophil total and differential counts, and neutrophil-to-lymphocyte ratio. Conversely, a generalized leukocyte decrease discriminated female COPD patients from the related controls. The impact of sex is further remarked by a decrease in adaptive immune cell subpopulations in males as opposed to a consistent increase of innate immune cell types in females correlating with disease severity.

Conclusion

These data indicate that the definition of specific changes of circulating leukocytes to be used as reliable biomarkers of the disease severity cannot be accomplished irrespectively of sex.

Differences Between Men and Women with Chronic Obstructive Pulmonary Disease

There are many differences between men and women in risk factor vulnerability and impact, symptom development, presentation, clinical manifestations, and outcomes of chronic obstructive pulmonary disease (COPD). These differences have been inadequately explored, which is of particular concern in view of the delay in diagnosis and treatment that occurs for both men and women, and the need to use all therapies in a targeted and tailored way for best clinical gain and least harm. Women are generally underrepresented in randomized trials, as are non-tobacco-related phenotypes of COPD. We must garner the information available to better describe optimal treatment approaches.

Gender specific airway gene expression in COPD sub-phenotypes supports a role of mitochondria and of different types of leukocytes

Chronic obstructive pulmonary disease (COPD) is a destructive inflammatory disease and the genes expressed within the lung are crucial to its pathophysiology. We have determined the RNAseq transcriptome of bronchial brush cells from 312 stringently defined ex-smoker patients. Compared to healthy controls there were for males 40 differentially expressed genes (DEGs) and 73 DEGs for females with only 26 genes shared. The gene ontology (GO) term “response to bacterium” was shared, with several different DEGs contributing in males and females. Strongly upregulated genes TCN1 and CYP1B1 were unique to males and females, respectively. For male emphysema (E)-dominant and airway disease (A)-dominant COPD (defined by computed tomography) the term “response to stress” was found for both sub-phenotypes, but this included distinct up-regulated genes for the E-sub-phenotype (neutrophil-related CSF3R, CXCL1, MNDA) and for the A-sub-phenotype (macrophage-related KLF4, F3, CD36). In E-dominant disease, a cluster of mitochondria-encoded (MT) genes forms a signature, able to identify patients with emphysema features in a confirmation cohort. The MT-CO2 gene is upregulated transcriptionally in bronchial epithelial cells with the copy number essentially unchanged. Both MT-CO2 and the neutrophil chemoattractant CXCL1 are induced by reactive oxygen in bronchial epithelial cells. Of the female DEGs unique for E- and A-dominant COPD, 88% were detected in females only. In E-dominant disease we found a pronounced expression of mast cell-associated DEGs TPSB2, TPSAB1 and CPA3. The differential genes discovered in this study point towards involvement of different types of leukocytes in the E- and A-dominant COPD sub-phenotypes in males and females.

Weak Handgrip at Index Admission for Acute Exacerbation of COPD Predicts All-Cause 30-Day Readmission

Rationale: Identifying patients hospitalized for acute exacerbations of COPD (AECOPD) who are at high risk for readmission is challenging. Traditional markers of disease severity such as pulmonary function have limited utility in predicting readmission. Handgrip strength, a component of the physical frailty phenotype, may be a simple tool to help predict readmission. Objective(s): To investigate if handgrip strength, a component of the physical frailty phenotype and surrogate for weakness, is a predictive biomarker of COPD readmission. Methods: This was a prospective, observational study of patients admitted to the inpatient general medicine unit at the University of Chicago Medicine, US. This study evaluated age, sex, ethnicity, degree of obstructive lung disease by spirometry (FEV1 percent predicted), and physical frailty phenotype (components include handgrip strength and walk speed). The primary outcome was all-cause hospital readmission within 30 days of discharge. Results: Of 381 eligible patients with AECOPD, 70 participants agreed to consent to participate in this study. Twelve participants (17%) were readmitted within 30 days of discharge. Weak grip at index hospitalization, defined as grip strength lower than previously established cut-points for sex and body mass index (BMI), was predictive of readmission (OR 11.2, 95% CI 1.3, 93.2, p = 0.03). Degree of airway obstruction (FEV1 percent predicted) did not predict readmission (OR 1.0, 95% CI 0.95, 1.1, p = 0.7). No non-frail patients were readmitted. Conclusions: At a single academic center weak grip strength was associated with increased 30-day readmission. Future studies should investigate whether geriatric measures can help risk-stratify patients for likelihood of readmission after admission for AECOPD.

Sex and Gender Omic Biomarkers in Men and Women With COPD: Considerations for Precision Medicine

Sex and gender differences in lung health and disease are imperative to consider and study if precision pulmonary medicine is to be achieved. The development of reliable COPD biomarkers has been elusive, and the translation of biomarkers to clinical care has been limited. Useful and effective biomarkers must be developed with attention to clinical heterogeneity of COPD; inherent heterogeneity exists related to grouping women and men together in the studies of COPD. Considering sex and gender differences and influences related to -omics may represent progress in susceptibility, diagnostic, prognostic, and therapeutic biomarker development and clinical innovation to improve the lung health of men and women.

Sex differences in COPD management

Introduction: A growing body of evidence indicates that prevalence of chronic obstructive pulmonary disease (COPD) has been increasing more rapidly among women compared to men, but the available data on the differences between the sexes in the responses to the various COPD therapies are still scarce.Areas covered: The aim of this narrative review is to provide an overview of current knowledge on sex differences in COPD management.Expert opinion: There is no solid evidence of sex differences in response to usual COPD treatments but there are sex-related differences in management of patients with a clinical diagnosis of COPD. It is difficult to explain the reason for these differences, but most likely they are due to local prescribing habits, rather than solid scientific reasons. However, there are also signals of different sex-related responses, the qualification and quantification of which is difficult with the information currently available. These signals should lead to the inclusion of more women in clinical trials, but also to the design of prospective clinical studies to assess the possible differences linked to sex in COPD treatment responses, whose identification is an important step toward the definition of personalized COPD therapy.

Metabolomic Profiling Reveals Sex Specific Associations with Chronic Obstructive Pulmonary Disease and Emphysema

Susceptibility and progression of lung disease, as well as response to treatment, often differ by sex, yet the metabolic mechanisms driving these sex-specific differences are still poorly understood. Women with chronic obstructive pulmonary disease (COPD) have less emphysema and more small airway disease on average than men, though these differences become less pronounced with more severe airflow limitation. While small studies of targeted metabolites have identified compounds differing by sex and COPD status, the sex-specific effect of COPD on systemic metabolism has yet to be interrogated. Significant sex differences were observed in 9 of the 11 modules identified in COPDGene. Sex-specific associations by COPD status and emphysema were observed in 3 modules for each phenotype. Sex stratified individual metabolite associations with COPD demonstrated male-specific associations in sphingomyelins and female-specific associations in acyl carnitines and phosphatidylethanolamines. There was high preservation of module assignments in SPIROMICS (SubPopulations and InteRmediate Outcome Measures In COPD Study) and similar female-specific shift in acyl carnitines. Several COPD associated metabolites differed by sex. Acyl carnitines and sphingomyelins demonstrate sex-specific abundances and may represent important metabolic signatures of sex differences in COPD. Accurately characterizing the sex-specific molecular differences in COPD is vital for personalized diagnostics and therapeutics.

Evaluation of Suboptimal Peak Inspiratory Flow in Patients with Stable COPD

Objective: Although the importance of assessing inspiratory flow in the selection of treatments for chronic obstructive pulmonary disease (COPD) is understood, evaluation of this factor is not yet widespread or standardized. The objective of the present work was to evaluate the peak inspiratory flow (PIF) of patients with COPD and to explore the variables associated with a suboptimal PIF. Methods: An observational, cross-sectional study was carried out at specialized nursing consultations over a period of 6 months. We collected clinical data as well as data on symptoms, treatment adherence, and patient satisfaction with their inhalers via questionnaires. PIF was determined using the In-Check Dial G16^® device (Clement Clarke International, Ltd., Harlow, UK). In each case, the PIF was considered suboptimal when it was off-target for any of the prescribed inhalers. The association with suboptimal PIF was evaluated using multivariate logistic regression and the results were expressed as the odds ratio (OR) with 95% confidence interval (CI). Results: A total of 122 COPD patients were included in this study, of whom 34 (27.9%) had suboptimal PIF. A total of 229 inhalers were tested, of which 186 (81.2%) were dry powder devices. The multivariate analysis found an association between suboptimal PIF and age (OR = 1.072; 95% CI (1.019, 1.128); p = 0.007) and forced vital capacity (OR = 0.961; 95% CI (0.933, 0.989); p = 0.006). Conclusions: About a third of patients in complex specialized COPD care have suboptimal PIFs, which is related to age and forced vital capacity.

Host, Gender, and Early-Life Factors as Risks for Chronic Obstructive Pulmonary Disease

Although smoking results in lung pathology in many, still not all smokers develop chronic obstructive pulmonary disease (COPD). Roughly a quarter of patients with COPD have never smoked. An understanding of both host and environmental factors beyond smoking that contribute to disease development remain critical to understanding disease prevention and ultimately effectively intervene. In this article, we summarize host factors, including genetics and gender, as well as early-life events that contribute to the development of COPD.