Sex differences in severe pulmonary emphysema

Exertional desaturation as a predictor of rapid lung function decline in COPD

BACKGROUND

To date, no clinical parameter has been associated with the decline in lung function other than emphysema severity in COPD.

OBJECTIVES

The main purpose of this study was to explore whether the rate of lung function decline differs between COPD patients with and without exertional desaturation.

METHODS

A total of 224 subjects were selected from the Korean Obstructive Lung Disease cohort. Exertional desaturation was assessed using the 6-min walk test (6MWT), and defined as a post-exercise oxygen saturation (SpO2) of < 90% or a ≥ 4% decrease. The cohort was divided into desaturator (n = 47) and non-desaturator (n = 177) groups.

RESULTS

There was a significant difference between the desaturator and non-desaturator groups in terms of the change in pre-bronchodilator forced expiratory volume in 1 s (FEV1) over a 3-year period of follow-up (p = 0.006). The mean rate of decline in FEV1 was greater in the desaturator group (33.8 ml/year) than in the non-desaturator group (11.6 ml/year). A statistically significant difference was also observed between the two groups in terms of the change in the St. George's Respiratory Questionnaire (SGRQ) total score over 3 years (p = 0.001).

CONCLUSIONS

This study suggests, for the first time, that exertional desaturation may be a predictor of rapid decline in lung function in patients with COPD. The 6MWT may be a useful test to predict a rapid lung function decline in COPD.

Prevalence of anxiety and depressive symptoms in adolescents with asthma: a meta-analysis and meta-regression

It remains unclear whether anxiety and depressive symptoms are more prevalent in adolescents with asthma when compared with healthy individuals. This meta-analysis aimed to evaluate the difference in the aggregate prevalence of depressive and anxiety symptoms between adolescents with asthma and healthy controls and to explore the underlying moderators that potentially explain the heterogeneity of the effect size. A meta-analysis of published work was performed using the random effects model. The differences in aggregate prevalence of depressive and anxiety symptoms between adolescents with asthma and healthy controls were determined. Meta-regression and subgroup analysis were performed to identify factors that may contribute to heterogeneity. A total of eight studies were eligible for analysis. The aggregate prevalence of depressive and anxiety symptoms was significantly higher among 3546 adolescents with asthma than that of 24,884 controls (depression, 0.27; 95% CI, 0.18.6-0.39 vs. 0.13; 95% CI, 0.09-0.19; anxiety, 0.33; 95% CI, 0.19-0.52 vs. 0.21; 95% CI, 0.12-0.33). The risk of developing depression and anxiety is significantly higher among adolescents with asthma when compared with controls (depression: pooled odds ratio, 2.09; 95% CI, 1.65-2.64; p < 0.001; anxiety: pooled odds ratio, 1.83; 95% CI, 1.63-2.07; p < 0.001). Meta-regression revealed that the proportions of Caucasian (p = 0.008) and smokers (p < 0.001) were significant moderators which explained the significant heterogeneity when comparing the risk of developing depressive symptoms among adolescent asthma patients vs. controls while age, gender, and severity of asthma were not significant. Family doctors, pediatricians, and healthcare providers should formulate strategies to detect depressive and anxiety symptoms in adolescents with asthma and offer psychological interventions to reduce the burden of psychiatric comorbidity.

Association of dopamine-related gene alleles, smoking behavior and decline in FEV1 in subjects with COPD: findings from the lung health study

Cigarette smoking is the major risk factor for chronic obstructive pulmonary disease (COPD). Specific dopamine related gene alleles have previously been found to be associated with smoking initiation, maintenance and cessation. We investigated the association between specific dopamine related gene alleles and both change in smoking behavior and lung function change over time in individuals with mild-to-moderate COPD. Subjects included a subset of participants in the Lung Health Study (LHS), a smoking intervention study in smokers with mild to moderate COPD. Smoking status was determined and lung function performed at baseline and annually for 5 years. In post-hoc analyses, we assessed the association of the dopamine receptor (DRD2) TaqI A1(+) allele (A1A1, A1A2 genotypes) and A1(-) allele (A2A2 genotype), and the dopamine transporter (DAT) 9R(+) allele (9R9R and 9R10R genotypes) and 9R(-) allele (10R10R genotype) with both changes in smoking status and lung function in a subset of LHS subjects. No significant associations were noted between variants in these genes and success in smoking cessation. However, in exploratory analyses that did not adjust for multiple comparisons, sustained male (but not female) quitters with the DRD2 A1(-) allele and/or the DAT 9R(+) allele showed an accelerated decline in FEV(1) similar to that of continuing smokers over 5 years after quitting smoking. These preliminary findings suggest that dopamine-related genes may play a role in the progression of COPD, at least in the subset of male ex-smokers whose disease continues to progress despite sustained quitting, and warrants additional confirmatory and mechanistic studies.

Physiological measurement of the small airways

Noninvasive physiological measurements are reviewed that have been reported in the literature with the specific aim being to study the small airways in lung disease. This has mostly involved at-the-mouth noninvasive measurement of flow, pressure or inert gas concentration, with the intent of deriving one or more indices that are representative of small airway structure and function. While these measurements have remained relatively low-tech, the effort and sophistication increasingly reside with the interpretation of such indices. When aspiring to derive information at the mouth about structural and mechanical processes occurring several airway generations away in a complex cyclically changing cul-de-sac structure, conceptual or semi-quantitative lung models can be valuable. Two assumptions that are central to small airway structure-function measurement are that of an average airway change at a given peripheral lung generation and of a parallel heterogeneity in airway changes. While these are complementary pieces of information, they can affect certain small airways tests in confounding ways. We critically analyzed the various small airway tests under review, while contending that negative outcomes of these tests are probably a true reflection of the fact that no change occurred in the small airways. Utmost care has been taken to not favor one technique over another, given that most current small airways tests still have room for improvement in terms of rendering their content more specific to the small airways. One way to achieve this could consist of the coupling of signals collected at the mouth to spatial information gathered from imaging in the same patient.

Quantitative pulmonary imaging using computed tomography and magnetic resonance imaging

Measurements of lung function, including spirometry and body plethesmography, are easy to perform and are the current clinical standard for assessing disease severity. However, these lung functional techniques do not adequately explain the observed variability in clinical manifestations of disease and offer little insight into the relationship of lung structure and function. Lung imaging and the image-based assessment of lung disease has matured to the extent that it is common for clinical, epidemiologic and genetic investigation to have a component dedicated to image analysis. There are several exciting imaging modalities currently being used for the non-invasive study of lung anatomy and function. In this review, we will focus on two of them; X-ray computed tomography and magnetic resonance imaging. Following a brief introduction of each method, we detail some of the most recent work being done to characterize smoking-related lung disease and the clinical applications of such knowledge.

Sex differences in the response of the alveolar macrophage proteome to treatment with exogenous surfactant protein-A

Background

Male wild type (WT) C57BL/6 mice are less capable of clearing bacteria and surviving from bacterial pneumonia than females. However, if an oxidative stress (acute ozone exposure) occurs before infection, the advantage shifts to males who then survive at higher rates than females. We have previously demonstrated that survival in surfactant protein-A (SP-A) knockout (KO) mice compared to WT was significantly reduced. Because the alveolar macrophage (AM) is pivotal in host defense we hypothesized that SP-A and circulating sex hormones are responsible for these sex differences. We used 2D-DIGE to examine the relationship of sex and SP-A on the AM proteome. The role of SP-A was investigated by treating SP-A KO mice with exogenous SP-A for 6 and 18 hr and studying its effects on the AM proteome.

Results

We found: 1) less variance between KO males and females than between the WT counterparts by principal component analysis, indicating that SP-A plays a role in sex differences; 2) fewer changes in females when the total numbers of significantly changing protein spots or identified whole proteins in WT or 18 hr SP-A-treated males or females were compared to their respective KO groups; 3) more proteins with functions related to chaperones or protease balance and Nrf2-regulated proteins changed in response to SP-A in females than in males; and 4) the overall pattern of SP-A induced changes in actin-related proteins were similar in both sexes, although males had more significant changes.

Conclusions

Although there seems to be an interaction between sex and the effect of SP-A, it is unclear what the responsible mechanisms are. However, we found that several of the proteins that were expressed at significantly higher levels in females than in males in WT and/or in KO mice are known to interact with the estrogen receptor and may thus play a role in the SP-A/sex interaction. These include major vault protein, chaperonin subunit 2 (beta) (CCT2), and Rho GDP alpha dissociation inhibitor. We conclude that sex differences exist in the proteome of AM derived from male and female mice and that SP-A contributes to these sex differences.

Contribution of the environment and comorbidities to chronic obstructive pulmonary disease phenotypes

* COPD is a heterogeneous disease, modified by environmental and intrinsic host factors. The interaction between COPD and its comorbidities is complex and bidirectional. * It has been estimated that the proportion of patients with COPD caused by cigarette smoking is between 80% and 90%. Risk factors associated with COPD in nonsmokers are numerous and incompletely understood, but a history of asthma or tuberculosis, exposure to traffic and outdoor pollution, and exposure to biomass smoke show the strongest associations. Other factors that may contribute to COPD phenotypes include gender, genetics, and the lung microbiome. * Certain comorbid conditions, such as cardiovascular disease and osteoporosis, are more common in the COPD patient population. Other comorbidities, such as overlap syndrome, the coexistence of COPD, and obstructive sleep apnea may not be as prevalent in COPD but are important because they may modify disease course. * Systemic inflammation may be pathogenically related to many comorbidities seen in COPD including cardiovascular disease, osteoporosis, metabolic syndrome, and depression. * Based on the data presented here, two general patterns of clinical features and comorbidities that share some associations are (1) emphysema, low BMI and osteoporosis and (2) chronic bronchitis, airway disease, high BMI, OSA, and diabetes. * The classification of patients with COPD into subgroups with shared characteristics and outcomes offers the potential for specific interventions. New research tools from the fields of epidemiology, immunology, imaging, and data analysis will be helpful in accomplishing this goal.

Emphysema distribution and annual changes in pulmonary function in male patients with chronic obstructive pulmonary disease

BACKGROUND

The progression of chronic obstructive pulmonary disease (COPD) considerably varies among patients. Those with emphysema identified by quantitative computed tomography (CT) are associated with the rapid progression assessed by forced expiratory volume in one second (FEV1). However, whether the rate of the decline in lung function is independently affected by the regional distribution or the severity of emphysema in the whole lung is unclear.

METHODS

We followed up 131 male patients with COPD for a median of 3.7 years. We measured wall area percent (WA%) in right apical segmental bronchus, total lung volume, percent low attenuation volume (LAV%), and the standard deviation (SD) of LAV% values from CT images of 10 isovolumetric partitions (SD-LAV) as an index of cranial-caudal emphysema heterogeneity. Annual changes in FEV1 were then determined using a random coefficient model and relative contribution of baseline clinical parameters, pulmonary function, and CT indexes including LAV%, SD-LAV, and WA% to annual changes in FEV1 were examined.

RESULTS

The mean (SD) annual change in FEV1 was -44.4 (10.8) mL. Multivariate random coefficient model showed that higher baseline FEV1, higher LAV%, current smoking, and lower SD-LAV independently contributed to an excessive decline in FEV1, whereas ratio of residual volume to total lung capacity, ratio of diffusing capacity to alveolar ventilation, and WA% did not, after adjusting for age, height, weight, and ratio of CT-measured total lung volume to physiologically-measured total lung capacity.

CONCLUSIONS

A more homogeneous distribution of emphysema contributed to an accelerated decline in FEV1 independently of baseline pulmonary function, whole-lung emphysema severity, and smoking status. In addition to whole-lung analysis of emphysema, CT assessment of the cranial-caudal distribution of emphysema might be useful for predicting rapid, progressive disease and for developing a targeted strategy with which to prevent disease progression.

Biomarkers in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a complex disease with multiple phenotypes that cannot be identified through measurement of lung function alone. The importance of COPD risk assessment, phenotype identification, and diagnosis of exacerbation magnify the need for validated biomarkers in COPD. A large number of potential biomarkers have already been assessed and some appear promising, in particular fibrinogen, which is likely to be the first COPD biomarker presented to the Food and Drug Administration for qualification in the drug approval process. Blood fibrinogen and c-reactive protein (CRP) have been associated with the presence of COPD and, in some instances, future risk of developing COPD in targeted populations. Sputum neutrophil counts have been used preliminarily as biomarkers of favorable response to therapy in COPD, but use in clinical settings may be limited. Other potential blood biomarkers include pulmonary and activation-regulated chemokine (PARC/CCL-18) and the clara cell secretory protein 16 (CC-16). Integrative indices, such as the BODE index, provide a framework to determine prognosis, predict outcome, and may be responsive to therapeutic interventions. Computed tomography provides a means to assess phenotypes and identify the relative extents of small airways disease and emphysema, which themselves may inform prognosis and therapeutic decision making. Fibrinogen and other markers of systemic inflammation are elevated in the context of acute COPD exacerbations and may also identify those at risk of accelerated lung function decline and hospitalization. So far, no single biomarker in COPD warrants wide acceptance emphasizing the need for future investigation of biomarkers in large-scale longitudinal studies.

Sex differences and sex steroids in lung health and disease

Sex differences in the biology of different organ systems and the influence of sex hormones in modulating health and disease are increasingly relevant in clinical and research areas. Although work has focused on sex differences and sex hormones in cardiovascular, musculoskeletal, and neuronal systems, there is now increasing clinical evidence for sex differences in incidence, morbidity, and mortality of lung diseases including allergic diseases (such as asthma), chronic obstructive pulmonary disease, pulmonary fibrosis, lung cancer, as well as pulmonary hypertension. Whether such differences are inherent and/or whether sex steroids play a role in modulating these differences is currently under investigation. The purpose of this review is to define sex differences in lung structure/function under normal and specific disease states, with exploration of whether and how sex hormone signaling mechanisms may explain these clinical observations. Focusing on adult age groups, the review addresses the following: 1) inherent sex differences in lung anatomy and physiology; 2) the importance of certain time points in life such as puberty, pregnancy, menopause, and aging; 3) expression and signaling of sex steroid receptors under normal vs. disease states; 4) potential interplay between different sex steroids; 5) the question of whether sex steroids are beneficial or detrimental to the lung; and 6) the potential use of sex steroid signaling as biomarkers and therapeutic avenues in lung diseases. The importance of focusing on sex differences and sex steroids in the lung lies in the increasing incidence of lung diseases in women and the need to address lung diseases across the life span.

Chronic obstructive pulmonary disease: Does gender really matter?

Background:

Limited data is available on the clinical expression of chronic obstructive pulmonary disease (COPD) from India. The impact of gender on expression of COPD has received even less attention. Apart from tobacco smoke, indoor air pollution, especially from biomass fuel may play an important role in development of COPD in women.

Materials and Methods:

Seven hundred and two patients of COPD were studied regarding the etiological and risk factors leading to COPD, gender-related differences in clinical presentation, radiological expression of COPD and the co-morbidities in COPD.

Results:

Tobacco smoke in the form of beedi smoking was the predominant smoke exposure in males, whereas smoke from biofuel burning was the predominant exposure in females. As compared to males, females were younger, reported more dyspnea, more severe bronchial obstruction, more exacerbations, and exhibited higher prevalence of systemic features. Also, females smoked less and had lesser incidence of productive cough, lower body mass index, lesser co-morbidities and less number of hospital admissions as compared to males. Males were more likely than females to have an emphysema-predominant phenotype, while airway-predominant disease was more common among females.

Conclusion:

The current study shows that gender-related differences do exist in COPD patients. Understanding these differences in etiological agent and clinical picture will help early diagnosis of COPD in females.

Equating quantitative emphysema measurements on different CT image reconstructions

PURPOSE

To mathematically model the relationship between CT measurements of emphysema obtained from images reconstructed using different section thicknesses and kernels and to evaluate the accuracy of the models for converting measurements to those of a reference reconstruction.

METHODS

CT raw data from the lung cancer screening examinations of 138 heavy smokers were reconstructed at 15 different combinations of section thickness and kernel. An emphysema index was quantified as the percentage of the lung with attenuation below -950 HU (EI950). Linear, quadratic, and power functions were used to model the relationship between EI950 values obtained with a reference 1 mm, medium smooth kernel reconstruction and values from each of the other 14 reconstructions. Preferred models were selected using the corrected Akaike information criterion (AICc), coefficients of determination (R2), and residuals (conversion errors), and cross-validated by a jackknife approach using the leave-one-out method.

RESULTS

The preferred models were power functions, with model R2 values ranging from 0.949 to 0.998. The errors in converting EI950 measurements from other reconstructions to the 1 mm, medium smooth kernel reconstruction in leave-one-out testing were less than 3.0 index percentage points for all reconstructions, and less than 1.0 index percentage point for five reconstructions. Conversion errors were related in part to image noise, emphysema distribution, and attenuation histogram parameters. Conversion inaccuracy related to increased kernel sharpness tended to be reduced by increased section thickness.

CONCLUSIONS

Image reconstruction-related differences in quantitative emphysema measurements were successfully modeled using power functions.

Impairment of quality of life in women with chronic obstructive pulmonary disease

BACKGROUND

There is ample evidence of the differences between genders in chronic obstructive pulmonary disease (COPD). The purpose of this study was to identify the factors that contribute to these differences.

METHODS

This was a multi-center, cross-sectional observational study including 4574 patients of 40 years of age and older who attended primary care and pulmonary clinics. Data were collected on COPD characteristics, comorbidities, quality of life as assessed by both the EuroQoL 5D questionnaire (EQ-5D) and the Airways Questionnaire 20 (AQ20), and prevalence of anxiety and depression. Data collected were compared between males and females.

RESULTS

Mean age was 67 years and 740 patients (16.7%) were female. Women were significantly younger, had better pulmonary function, and smoked less; however, they showed poorer quality of life (EQ-5D: 0.6 [SD = 0.3] versus 0.7 [0.3]; p < 0.001; and AQ20: 10.4 [SD = 4.6] versus 9.2 [SD = 4.5]; p < 0.001) and a higher rate of anxiety (34.5% versus 20.6%; p < 0.001) and depression (31.7% versus 22.1%; p < 0.001). In a multivariate analysis, female gender was significantly associated to poorer quality of life (AQ20) but not to a higher rate of dyspnea.

CONCLUSION

Women with COPD are younger and have lower rates of impaired lung function; however, they show poorer quality of life and more frequent COPD-associated anxiety and depression.

Chronic obstructive pulmonary disease exacerbations in the COPDGene study: associated radiologic phenotypes

PURPOSE

To test the hypothesis-given the increasing emphasis on quantitative computed tomographic (CT) phenotypes of chronic obstructive pulmonary disease (COPD)-that a relationship exists between COPD exacerbation frequency and quantitative CT measures of emphysema and airway disease.

MATERIALS AND METHODS

This research protocol was approved by the institutional review board of each participating institution, and all participants provided written informed consent. One thousand two subjects who were enrolled in the COPDGene Study and met the GOLD (Global Initiative for Chronic Obstructive Lung Disease) criteria for COPD with quantitative CT analysis were included. Total lung emphysema percentage was measured by using the attenuation mask technique with a -950-HU threshold. An automated program measured the mean wall thickness and mean wall area percentage in six segmental bronchi. The frequency of COPD exacerbation in the prior year was determined by using a questionnaire. Statistical analysis was performed to examine the relationship of exacerbation frequency with lung function and quantitative CT measurements.

RESULTS

In a multivariate analysis adjusted for lung function, bronchial wall thickness and total lung emphysema percentage were associated with COPD exacerbation frequency. Each 1-mm increase in bronchial wall thickness was associated with a 1.84-fold increase in annual exacerbation rate (P = .004). For patients with 35% or greater total emphysema, each 5% increase in emphysema was associated with a 1.18-fold increase in this rate (P = .047).

CONCLUSION

Greater lung emphysema and airway wall thickness were associated with COPD exacerbations, independent of the severity of airflow obstruction. Quantitative CT can help identify subgroups of patients with COPD who experience exacerbations for targeted research and therapy development for individual phenotypes.

BODE index and quality of life in advanced chronic obstructive pulmonary disease before and after lung transplantation

BACKGROUND

The BODE index (Body mass index, Obstruction, Dyspnea, Exercise), predicts the risk of death in patients with chronic obstructive pulmonary disease (COPD), and is used to identify candidates for lung transplantation. We hypothesized that a higher BODE index would be associated with worse health-related quality of life (HRQL) in advanced COPD, and with larger improvements in HRQL after transplantation.

METHODS

In this cohort study (n = 112), we administered the St. George's Respiratory Questionnaire (SGRQ), 36-Item Short Form (SF-36), Visual Analog Scale, Standard Gamble and EuroQol Group 5-Dimension (EQ-5D) index to otherwise healthy COPD patients with a FEV(1) <50% predicted. We compared mean HRQL values across BODE score groups, and tested for linear trends. In patients who received lung transplants during the study period, we compared SGRQ scores before and early (mean 4 months) after transplantation.

RESULTS

BODE was directly associated with SGRQ and inversely related to all other HRQL measures (p < 0.05). Early post-transplant improvements in HRQL were also seen across the spectrum of BODE scores from 5 to 10.

CONCLUSIONS

The BODE score is a significant predictor of HRQL in patients with severe COPD. We noted dramatic improvements in HRQL after transplantation, which appeared similar in magnitude for patients with pre-transplant BODE scores of 5 or 6 and 7 to 10, despite the difference in expected survival between these two groups. The association of the BODE score with HRQL further supports its use in identifying potential candidates for lung transplantation.

Gender differences of airway dimensions in anatomically matched sites on CT in smokers

RATIONALE AND OBJECTIVES

There are limited data on, and controversies regarding gender differences in the airway dimensions of smokers. Multi-detector CT (MDCT) images were analyzed to examine whether gender could explain differences in airway dimensions of anatomically matched airways in smokers.

MATERIALS AND METHODS

We used VIDA imaging software to analyze MDCT scans from 2047 smokers (M:F, 1021:1026) from the COPDGene® cohort. The airway dimensions were analyzed from segmental to subsubsegmental bronchi. We compared the differences of luminal area, inner diameter, wall thickness, wall area percentage (WA%) for each airway between men and women, and multiple linear regression including covariates (age, gender, body sizes, and other relevant confounding factors) was used to determine the predictors of each airway dimensions.

RESULTS

Lumen area, internal diameter and wall thickness were smaller for women than men in all measured airway (18.4 vs 22.5 mm(2) for segmental bronchial lumen area, 10.4 vs 12.5 mm(2) for subsegmental bronchi, 6.5 vs 7.7 mm(2) for subsubsegmental bronchi, respectively p < 0.001). However, women had greater WA% in subsegmental and subsubsegmental bronchi. In multivariate regression, gender remained one of the most significant predictors of WA%, lumen area, inner diameter and wall thickness.

CONCLUSION

Women smokers have higher WA%, but lower luminal area, internal diameter and airway thickness in anatomically matched airways as measured by CT scan than do male smokers. This difference may explain, in part, gender differences in the prevalence of COPD and airflow limitation.

Comparison of airway remodelling assessed by computed tomography in asthma and COPD

BACKGROUND

Few studies have directly compared airway remodelling assessed by computed tomography (CT) between asthma and chronic obstructive pulmonary disease (COPD). The present study was conducted to determine whether there are any differences between the two diseases with similar levels of airflow limitation under clinically stable conditions.

METHODS

Subjects included older male asthmatic patients (n = 19) showing FEV(1)/FVC <70% with smoking history less than 5-pack/year. Age- and sex-matched COPD patients (n = 28) who demonstrated similar airflow limitation as asthmatic patients and age-matched healthy non-smokers (n = 13) were recruited. Using proprietary software, eight airways were selected in the right lung, and wall area percent (WA%) and airway luminal area (Ai) were measured at the mid-portion of the 3rd to 6th generation of each airway. For comparison, the average of eight measurements per generation was recorded.

RESULTS

FEV(1)% predicted and FEV(1)/FVC was similar between asthma and COPD (82.3 ± 3.3% vs. 77.6 ± 1.8% and 57.7 ± 1.6% vs. 57.9 ± 1.4%). At any generation, WA% was larger and Ai was smaller in asthma, both followed by COPD and then controls. Significant differences were observed between asthma and controls in WA% of the 3rd to 5th generation and Ai of any generation, while no differences were seen between COPD and controls. There were significant differences in Ai of any generation between asthma and COPD.

CONCLUSIONS

Airway remodelling assessed by CT is more prominent in asthma compared with age- and sex-matched COPD subjects in the 3rd- to 6th generation airways when airflow limitations were similar under stable clinical conditions.

Prevalence of depressive symptoms in patients with chronic obstructive pulmonary disease: a systematic review, meta-analysis and meta-regression

OBJECTIVE

This meta-analysis was aimed to evaluate the differences in aggregated prevalence of depressive symptoms among people with chronic obstructive pulmonary disease (COPD) as compared to controls without COPD and to determine underlying moderators to explain potential heterogeneity of prevalence.

METHODS

A meta-analysis of published work was performed using the random effect model. A total of eight studies were identified. We calculated the differences in prevalence proportion of depressive symptoms in patients with COPD versus controls. Meta-regression and subgroup analysis were performed to identify factors that may contribute to heterogeneity.

RESULTS

The prevalence proportion of depressive symptoms was found to be significantly higher (pooled odds ratio: 2.81; 95% CI: 1.69-4.66) among 39587 individuals with COPD as compared to 39,431 controls (24.6%, 95% CI: 20.0-28.6% vs. 11.7%, 95% CI: 9-15.1%). Meta-regression was conducted to account for the heterogeneity of the prevalence proportion, but moderators like mean age, gender, mean FEV(1) and proportion of current smokers among COPD patients were nonsignificant and could not explain heterogeneity in prevalence of depressive symptoms. Subgroup analyses showed no significant differences based on different methods of assessment of depressive symptoms and countries sampled.

CONCLUSION

This meta-analytical review identified higher prevalence of depressive symptoms among COPD patients, and meta-regression showed that demographic and clinical factors were not the determinants of heterogeneity in prevalence of depressive symptoms.

Sex differences in exertional dyspnea in patients with mild COPD: physiological mechanisms

The purpose of this study was to evaluate the physiological basis for sex-differences in exercise-induced dyspnea in patients with mild COPD. We compared operating lung volumes, breathing pattern and dyspnea during incremental cycling in 32 men (FEV(1)=86±10% predicted) and women (FEV(1)=86±12% predicted) with mild COPD and 32 age-matched controls. There were no sex differences in dyspnea in the control group at any work-rate or ventilation (V(E)). Women with COPD had significantly greater dyspnea than men at 60 and 80 W. At 80 W, dyspnea ratings were 5.7±2.3 and 3.3±2.5 Borg units (P<0.05) and the V(E) to maximal ventilatory capacity ratio was 72% and 55% in women and men, respectively (P<0.05). Comparable increases in dynamic hyperinflation were seen in both male and female COPD groups at symptom limitation but women reached tidal volume constraints at a lower work rate and V(E) than men. Superimposing mild COPD on the normal aging effects had greater sensory consequences in women because of their naturally reduced ventilatory reserve.

Clinical and radiographic predictors of GOLD-unclassified smokers in the COPDGene study

RATIONALE

A significant proportion of smokers have lung function impairment characterized by a reduced FEV(1) with a preserved FEV(1)/FVC ratio. These smokers are a poorly characterized group due to their systematic exclusion from chronic obstructive pulmonary disease (COPD) studies.

OBJECTIVES

To characterize the clinical, functional, and radiographic features of Global Initiative for Chronic Obstructive Lung Disease (GOLD)-Unclassified (FEV(1)/FVC ≥ 0.7 and FEV(1) < 80% predicted) and lower limits of normal (LLN)-unclassified (FEV(1)/FVC ≥ LLN and FEV(1) < LLN) subjects compared to smokers with normal lung function and subjects with COPD.

METHODS

Data from the first 2,500 subjects enrolled in the COPDGene study were analyzed. All subjects had 10 or more pack-years of smoking and were between the ages of 45 and 80 years. Multivariate regression models were constructed to determine the clinical and radiological variables associated with GOLD-Unclassified (GOLD-U) and LLN-Unclassified status. Separate multivariate regressions were performed in the subgroups of subjects with complete radiologic measurement variables available.

MEASUREMENTS AND MAIN RESULTS

GOLD-U smokers account for 9% of smokers in COPDGene and have increased body mass index (BMI), a disproportionately reduced total lung capacity, and a higher proportion of nonwhite subjects and subjects with diabetes. GOLD-U subjects exhibit increased airway wall thickness compared to smoking control subjects and decreased gas trapping and bronchodilator responsiveness compared to subjects with COPD. When LLN criteria were used to define the "unclassified" group, African American subjects were no longer overrepresented. Both GOLD-U and LLN-Unclassified subjects demonstrated a wide range of lung function impairment, BMI, and percentage of total lung emphysema.

CONCLUSIONS

Subjects with reduced FEV(1) and a preserved FEV(1)/FVC ratio are a heterogeneous group with significant symptoms and functional limitation who likely have a variety of underlying etiologies beyond increased BMI. Clinical trial registered with www.clinicaltrials.gov (NCT000608764).

Tobacco use and cessation among women: research and treatment-related issues

The prevalence of tobacco use in women has increased over the past century. This has resulted in dramatic increases in smoking-related lung diseases, such as chronic obstructive pulmonary disease (COPD) and lung cancer. There is growing literature suggesting that women may be more susceptible than men to the effects of tobacco and to the development of COPD. Women may also have specific barriers that interfere with smoking cessation. This article addresses possible differences in lung function decline and nicotine metabolism in women compared to men. Differences in COPD between the sexes are discussed. Finally, barriers to smoking cessation in women are presented.

Twelve-year cumulative incidence of airflow obstruction among Japanese males

BACKGROUND

To date, there is very limited longitudinal data on COPD and incidence estimates in Japan. The aim of this study was to investigate the 12-year cumulative incidence of airflow obstruction (COPD) in Japanese males.

METHODS

This study included 913 male subjects, aged 30-76 years, who underwent lung function tests at a medical check-up in 1994 (baseline), 1999, and 2006. The study group consisted of 263 persistent never smokers, 296 early quitters, 117 late quitters, and 237 persistent smokers without airflow obstruction at baseline. The 12-year cumulative incidence of airflow obstruction was estimated. The spirometric criteria for diagnosis of airflow obstruction were forced expiratory volume in 1 second (FEV(1))/forced vital capacity (FVC) of <0.7 and 5th percentile lower limit of normal (FEV(1)/FVC<LLN).

RESULTS

The 12-year cumulative incidences of airflow obstruction using fixed criteria and LLN criteria were 5.3%, 7.6% in persistent never smokers, 10.5%, 10.1% in early quitters, 12.0%, 14.5% in late quitters, 13.5%, 17.3% in persistent smokers, respectively. In logistic regression models, the odds ratio (OR) of developing airflow obstruction defined using the fixed criteria and the LLN criteria increased with a history of smoking status and increasing pack-years of smoking. When using the LLN criteria to define obstruction compared with fixed criteria, higher incidence rates among aged <60 and lower incidence rates among aged ≥60 were observed.

CONCLUSION

The cumulative incidence of airflow obstruction defined using the fixed ratio and LLN criteria was strongly associated with smoking status. This study suggested that early cessation of smoking may prevent the development of airflow obstruction among smokers.

Polymorphisms in the superoxide dismutase-3 gene are associated with emphysema in COPD

Superoxide dismutase-3 (SOD3) is a major extracellular antioxidant enzyme, and previous studies have indicated a possible role of this gene in chronic obstructive pulmonary disease (COPD). We hypothesized that polymorphisms in the SOD3 gene would be associated with COPD and COPD-related phenotypes. We genotyped three SOD3 polymorphisms (rs8192287 (E1), rs8192288 (I1), and rs1799895 (R213G)) in a case-control cohort, with severe COPD cases from the National Emphysema Treatment Trial (NETT, n = 389) and smoking controls from the Normative Aging Study (NAS, n = 472). We examined whether the single nucleotide polymorphisms (SNPs) were associated with COPD status, lung function variables, and quantitative computed tomography (CT) measurements of emphysema and airway wall thickness. Furthermore, we tried to replicate our initial findings in two family-based studies, the International COPD Genetics Network (ICGN, n = 3061) and the Boston Early-Onset COPD Study (EOCOPD, n = 949). In NETT COPD cases, the minor alleles of SNPs E1 and I1 were associated with a higher percentage of emphysema (%LAA950) on chest CT scan (p = .029 and p = .0058). The association with E1 was replicated in the ICGN family study, where the minor allele was associated with more emphysema (p = .048). Airway wall thickness was positively associated with the E1 SNP in ICGN; however, this finding was not confirmed in NETT. Quantitative CT data were not available in EOCOPD. The SNPs were not associated with lung function variables or COPD status in any of the populations. In conclusion, polymorphisms in the SOD3 gene were associated with CT emphysema but not COPD susceptibility, highlighting the importance of phenotype definition in COPD genetics studies.

Quantitative CT measures of emphysema and airway wall thickness are related to D(L)CO

There is limited knowledge on the relationship between diffusing capacity of the lung for carbon monoxide (D(L)CO) and quantitative computed tomography (CT) measures of emphysema and airway wall thickness.

STUDY QUESTION

What is the relationship between D(L)CO and the quantitative CT measures of emphysema and airway wall thickness in subjects with and without COPD?

METHODS

We included 288 COPD subjects (70% men) and 425 non-COPD subjects (54% men). All subjects were current or ex-smokers older than 40 years and all subjects underwent spirometry, diffusing capacity tests and CT examination. Quantitative CT measures included % low attenuation areas < -950 HU (%LAA) and standardized airway wall thickness (AWT-Pi10).

RESULTS

Multiple linear regression analyses showed significant associations between D(L)CO and both %LAA and AWT-Pi10 in the COPD group. The adjusted regression coefficients (SE) for D(L)CO (mmol min(-1) kPa(-1)) were -1.15 (0.11) per 10% increase in %LAA and 0.08 (0.03) per 0.1 mm increase in AWT-Pi10, and the models' adjusted R(2) was 0.65 and 0.49, respectively.

CONCLUSIONS

CT measured emphysema explains a large fraction of the variation of D(L)CO among COPD subjects, and more so in men. Airway wall thickness is also significantly associated with D(L)CO, but explains a much smaller fraction of the variation.

Gender differences in COPD: are women more susceptible to smoking effects than men?

BACKGROUND

The number of female smokers developing chronic obstructive pulmonary disease (COPD) is rapidly increasing, but whether or not there exists a differential susceptibility by gender remains controversial.

METHODS

How smoking behaviour and subsequent lung function reduction differed by gender was examined in a study including 954 subjects with COPD and 955 subjects without COPD. The study focused on two subgroups: subjects with COPD <60 years of age (early-onset group, n=316) and subjects with COPD with <20 pack-years of smoking (low exposure group, n=241).

RESULTS

In the low exposure group, female subjects with COPD had lower forced expiratory volume in 1 s (FEV(1)) % predicted (48.7% vs 55.8%, p=0.001) and more severe disease (50.4% vs 35.6%, p=0.020, in GOLD (Global Initiative for Chronic Obstructive Lung Disease) stage 3 and 4) than male subjects with COPD. Females also had lower FEV(1)% predicted (50.6% vs 56.0%, p=0.006) and more severe COPD (41.7% vs 31.1% in GOLD stage 3 and 4, p=0.050) in the early-onset group. Using multivariate regression, female gender was associated with 5.7% lower FEV(1)% predicted in the low exposure group (p=0.012) and a similar trend was observed in the early-onset group (p=0.057). The number of pack-years was not significantly associated with lung function in female subjects with COPD in this study, and the dose-response relationship between smoking and lung function differed by gender at lower levels of smoking exposure. Interaction analysis suggested that the effect of smoking on lung function might be different by gender (p=0.027 in all subjects with COPD).

CONCLUSIONS

Female gender was associated with lung function reduction and more severe disease in subjects with COPD with early onset of disease or low smoking exposure. The findings may suggest a gender difference in susceptibility to the lung-damaging effects of cigarette smoking, but alternative explanations should be considered.

Gender differences in predictors of health status in patients with COPD

OBJECTIVE

To evaluate the health status (HS) of COPD patients and to identify the main predictors of HS in these patients according to gender.

METHODS

The study included 90 COPD patients (60 males and 30 females; mean age = 64 +/- 9 years) with a wide range of airway obstruction disorders (mean FEV1 = 56 +/- 19% of predicted). The men were individually matched to the women by % of predicted FEV1 (ratio: 2:1). The patients were assessed regarding body composition; six-minute walk distance; perception of dyspnea using the Modified Medical Research Council Dyspnea Scale; Saint George's Respiratory Questionnaire (SGRQ); Charlson comorbidity index; and the multidimensional Body mass index, airway Obstruction, Dyspnea, and Exercise capacity (BODE) index. Multiple linear regression analysis was performed to identify the predictors of HS by gender.

RESULTS

Impairment of HS was greater among the women than among the men for SGRQ total score and for all SGRQ domains (total: 51 +/- 18% vs. 38 +/- 19%; p = 0.002; symptoms: 61 +/- 22% vs. 42 +/- 21%; p < 0.001; activity: 62 +/- 18% vs. 49 +/- 21%; p = 0.004; and impact: 41 +/- 19% vs. 27 +/- 18%; p = 0.001). The multiple linear regression showed that age and perception of dyspnea correlated with SGRQ total score for both genders (males, r(2) = 0.42; females, r(2) = 0.70; p < 0.05).

CONCLUSIONS

Our results showed an association between gender and HS in COPD patients. Age and dyspnea are determinants of HS in both genders.

Sex differences in mortality and clinical expressions of patients with chronic obstructive pulmonary disease. The TORCH experience

RATIONALE

There is limited knowledge regarding sex differences and outcomes in patients with chronic obstructive pulmonary disease (COPD).

OBJECTIVES

Determine sex differences in survival, causes of death, and patient-centered outcomes in the 3-year Toward a Revolution in COPD Health (TORCH) study.

METHODS

A total of 1,481 women and 4,631 men with COPD were enrolled in TORCH, a trial comparing salmeterol, 50 μg, plus fluticasone propionate, 500 μg, twice a day and each component individually. Causes of death were determined by an endpoint committee. Sex differences in survival were explored using a Cox proportional hazards model adjusted for other baseline factors. Exacerbation rate was compared using a negative binomial model. Dyspnea was evaluated using the Medical Research Council scale and health status using the St. George's Respiratory Questionnaire.

MEASUREMENTS AND MAIN RESULTS

At baseline, women were younger (63 vs. 66 yr), had higher FEV(1) (47% vs. 44% predicted), and worse St. George's Respiratory Questionnaire (51.3 vs. 48.7) and Medical Research Council score. During the study, 707 (15.3%) men and 168 (11.3%) women died. After adjusting for differences in baseline factors, the risk of dying was 16% higher in men than in women; however, this was not statistically significant (hazard ratio 1.16 [95% CI, 0.98-1.39]). Causes of death were similar in women and men. Exacerbation rate was 25% higher in women than in men.

CONCLUSIONS

Women enrolled in TORCH had a lower mortality rate than men but similar causes of death. The risk of dying was similar in women and men after adjusting for important baseline variables. Women reported more exacerbations, and worse dyspnea and health status scores than men. Clinical trial registered with www.clinicaltrials.gov (NCT00268216).

Emphysema presence, severity, and distribution has little impact on the clinical presentation of a cohort of patients with mild to moderate COPD

BACKGROUND

Phenotypic characterization of patients with COPD may have potential prognostic and therapeutic implications. Available information on the relationship between emphysema and the clinical presentation in patients with COPD is limited to advanced stages of the disease. The objective of this study was to describe emphysema presence, severity, and distribution and its impact on clinical presentation of patients with mild to moderate COPD.

METHODS

One hundred fifteen patients with COPD underwent clinical and chest CT scan evaluation for the presence, severity, and distribution of emphysema. Patients with and without emphysema and with different forms of emphysema distribution (upper/lower/core/peel) were compared. The impact of emphysema severity and distribution on clinical presentation was determined.

RESULTS

Fifty percent of the patients had mild homogeneously distributed emphysema (1.84; 0.76%-4.77%). Upper and core zones had the more severe degree of emphysema. Patients with emphysema were older, more frequently men, and had lower FEV(1)%, higher total lung capacity percentage, and lower diffusing capacity of the lung for carbon monoxide. No differences were found between the clinical or physiologic parameters of the different emphysema distributions.

CONCLUSIONS

In patients with mild to moderate COPD, although the presence of emphysema has an impact on physiologic presentation, its severity and distribution seem to have little impact on clinical presentation.

Airflow limitation and airway dimensions assessed per bronchial generation in older asthmatics

BACKGROUND

Computed tomography (CT) has been used for non-invasive quantitative assessment of airway dimensions, potentially showing airway remodeling, in asthma. However, most studies have examined either only one airway or only airways in anatomically unidentified cross-sections. Using software capable of precisely identifying the generation of airways and measuring airway dimensions perpendicular to the long axis of airways, we examined, in older patients with stable asthma, how inter-subject variation in airway dimensions correlated among the 3rd to 6th generation of airways, and then examined relationships between airway dimensions of each generation and indices of airflow limitation.

METHODS

Subjects aged ≥55 years old comprised 59 asthmatic patients who underwent CT and pulmonary function tests on the same day. We measured airway wall area (WA%) and inner luminal area (Ai) from the 3rd to the 6th generation of eight bronchi in the right lung.

RESULTS

Excellent correlations were identified for both WA% and Ai among the generations (r = 0.744-0.930 for WA%) when we took the average of all measured bronchi per generation as a personal representative value. Significant correlations of airflow limitation indices with both WA% and Ai/BSA were found at each of the 3rd to 6th generations with similar correlation coefficients (WA% for FEV(1) %predicted, r = -0.410 to -0.556).

CONCLUSIONS

In older patients with stable asthma, airway wall thickening and narrowing might occur in a parallel manner through 3rd to 6th generation airways. Airway dimensions at these areas of airways may thus have significant and similar correlations with indices of airflow limitation.

Diagnostic imaging in COPD

Chronic obstructive pulmonary disease (COPD) is a pathological pulmonary condition characterized by expiratory airflow obstruction due to emphysematous destruction of the lung parenchyma and small airways remodeling. Although spirometry is a very useful diagnostic tool for screening large groups of smokers, it cannot readily differentiate the etiologies of COPD and thus has limited utility in characterizing subjects for clinical and investigational purposes. There has been a longstanding interest in thoracic imaging and its role in the in vivo characterization of smoking-related lung disease. Research in this area has spanned readily available modalities such as chest -ray and computed tomography to more advanced imaging techniques such as optical coherence tomography (OCT) and magnetic resonance imaging (MRI). Although the chest x-ray is almost universally available, it lacks sensitivity in detecting both airway disease and mild emphysema and is not generally amenable to objective analysis. Computed tomography has become the standard modality to objectively visualize lung disease. It can provide useful measures of the presence and extent of emphysema, airway disease, and, more recently, pulmonary vascular disease for clinical correlation. It does, however, face limitations in standardization across brands and generations of scanners, and the ionizing radiation associated with image acquisition is of concern to both patients and health care providers. Newer techniques such as OCT and MRI offer exciting in vivo insights into lung structure and function that were previously available only in necropsy specimens and physiology laboratories. Given the more limited availability of these techniques, they will be viewed here as adjuncts to computed tomographic imaging.

Gender influences Health-Related Quality of Life in IPF

BACKGROUND

HRQL in IPF patients is impaired. Data from other respiratory diseases led us to hypothesize that significant gender differences in HRQL in IPF also exist.

METHODS

Data were drawn from the NIH-sponsored Lung Tissue Research Consortium (LTRC). Demographic and pulmonary physiology data along with MMRC, SF-12, and SGRQ scores from women vs. men were compared with two-sample t-tests. Multivariate linear regression was used to examine the association between SF-12 component scores and gender while adjusting for other relevant variables.

RESULTS

The study sample consisted of 147 men and 74 women. Among several baseline variables, only DL(CO)% predicted differed between women and men, (43.7 vs. 38.0, p=0.03). In general, men exhibited lower (better) MMRC scores (1.7 vs. 2.4, p=0.02), particularly those with milder disease as measured by DL(CO)% predicted. In an adjusted analysis, SF-12 PCS scores in men were lower (worse) than women (p=0.01), an effect that was more pronounced in men with greater dyspnea scores. In a similar analysis, SF-12 MCS scores in women were lower than men (worse) (48.3 vs. 54.4, p=0.0004), an effect that was more pronounced in women with greater dyspnea scores.

CONCLUSIONS

Significant gender differences in HRQL exist in IPF. As compared to women, men reported less severe dyspnea, had worse SF-12 PCS scores, but better SF-12 MCS scores. Dyspnea appears to have a greater impact on the physical HRQL of men and the emotional HRQL of women. An improved understanding of the mechanism behind these differences is needed to better target interventions.

Lung function in young adults predicts airflow obstruction 20 years later

OBJECTIVE

The burden of obstructive lung disease is increasing, yet there are limited data on its natural history in young adults. To determine in a prospective cohort of generally healthy young adults the influence of early adult lung function on the presence of airflow obstruction in middle age.

METHODS

A longitudinal study was performed of 2496 adults who were 18 to 30 years of age at entry, did not report having asthma, and returned at year 20. Airflow obstruction was defined as an forced expiratory volume in 1 second/forced vital capacity ratio less than the lower limit of normal.

RESULTS

Airflow obstruction was present in 6.9% and 7.8% of participants at years 0 and 20, respectively. Less than 10% of participants with airflow obstruction self-reported chronic obstructive pulmonary disease. In cross-sectional analyses, airflow obstruction was associated with less education, smoking, and self-reported chronic obstructive pulmonary disease. Low forced expiratory volume in 1 second, forced expiratory volume in 1 second/forced vital capacity ratio, and airflow obstruction in young adults were associated with low lung function and airflow obstruction 20 years later. Of those with airflow obstruction at year 0, 52% had airflow obstruction 20 years later. The forced expiratory volume in 1 second/forced vital capacity at year 0 was highly predictive of airflow obstruction 20 years later (c-statistic 0.91; 95% confidence interval, 0.89-0.93). The effect of cigarette smoking on lung function decline with age was most evident in young adults with preexisting airflow obstruction.

CONCLUSION

Airflow obstruction is mostly unrecognized in young and middle-aged adults. Low forced expiratory volume in 1 second, low forced expiratory volume in 1 second/forced vital capacity ratio, airflow obstruction in young adults, and smoking are highly predictive of low lung function and airflow obstruction in middle age.

Effect of tiotropium in men and women with COPD: results of the 4-year UPLIFT trial

BACKGROUND

Gender differences may occur in many chronic diseases. We have examined the influence of gender in chronic obstructive pulmonary disease (COPD) on long-term responses to tiotropium.

METHODS

Subgroup analysis of data from the Understanding the Potential Long-term Impact of Tiotropium (UPLIFT) trial (4-year, randomized, double-blind, placebo-controlled trial of tiotropium in patients with COPD).

RESULTS

Of 5992 patients, 75% were men and 25% women. Mean age was 65 and 63 years, respectively. Baseline post-bronchodilator forced expiratory volume in 1s (FEV(1))=47% predicted(men) and 49% predicted(women). St George's Respiratory Questionnaire (SGRQ) total score was 44.9 and 48.7units, respectively. At 48 months, improvement in trough FEV(1) over control was 92mL(men) and 77mL(women) (p<0.001 for both), with no differences in the rate of decline (trial primary endpoint). Hazard ratio (HR) (95% confidence interval [CI]) for first exacerbation (tiotropium/placebo) was 0.87(0.81, 0.93)(men) and 0.83(0.74, 0.94)(women). Number of exacerbations (per patient-year) was reduced with tiotropium in men (from 0.82 to 0.71) and women (from 0.92 to 0.77) (p<0.005 for both). HR (95% CI) for a hospitalized exacerbation was 0.89(0.79, 0.99) and 0.77(0.62, 0.94), respectively. HR (95% CI) for mortality during treatment was 0.85(0.72, 0.99)(men) and 0.85(0.62, 1.18)(women). Improvements in SGRQ total score (tiotropium-control) at 1, 2, 3 and 4 years were: -2.8, -2.3, -3.6, -2.4(men) and -2.7, -2.6, -2.6, -2.1(women) (p<0.05 for all).

CONCLUSION

Long-term treatment of COPD with tiotropium improves lung function, exacerbations and health status in men and women, with similar magnitudes of benefit. Boehringer Ingelheim trial 205.235; ClinicalTrials.gov: NCT00144339.

A randomized controlled trial of cognitive behavioral therapy for anxiety and depression in COPD

BACKGROUND

Previous research indicates a high prevalence of untreated anxiety and depression in patients with chronic obstructive pulmonary disease (COPD). The current study examined the effect of cognitive behavioral therapy (CBT) in groups for co-morbid, clinically significant anxiety and depression in COPD outpatients of both sexes.

METHODS

In a randomized, controlled trial, CBT (n = 25) was compared with enhanced standard care (n = 26). Participants in both conditions were followed up at 2 and 8 months from baseline. Main outcome measures comprised the Beck Anxiety Inventory and the Beck Depression Inventory-II. Measures of health status and sleep were included as secondary outcomes. The effects of sex and age were also investigated.

RESULTS

CBT resulted in improvement in symptoms of anxiety and depression, with effect sizes of 1.1 and 0.9 at post-treatment, respectively. The improvement was maintained at the 8-month follow-up, with effect sizes of 1.4 and 0.9. In the control group, there was no significant change. Compared to men, women had higher symptom levels throughout the whole study period. Younger patients had more anxiety and depression, age had also differential effects in the two groups on change in depressive symptoms. Changes in sleep and health status were small in both groups.

CONCLUSIONS

The findings indicate that CBT may provide rapid symptom relief for COPD patients with clinically significant anxiety and depression, and underline the need for integrating mental health care into the overall medical regimen for COPD.

Anxiety is associated with diminished exercise performance and quality of life in severe emphysema: a cross-sectional study

Background

Anxiety in patients with chronic obstructive pulmonary disease (COPD) is associated with self-reported disability. The purpose of this study is to determine whether there is an association between anxiety and functional measures, quality of life and dyspnea.

Methods

Data from 1828 patients with moderate to severe emphysema enrolled in the National Emphysema Treatment Trial (NETT), collected prior to rehabilitation and randomization, were used in linear regression models to test the association between anxiety symptoms, measured by the Spielberger State Trait Anxiety Inventory (STAI) and: (a) six-minute walk distance test (6 MWD), (b) cycle ergometry peak workload, (c) St. Georges Respiratory Questionnaire (SRGQ), and (d) UCSD Shortness of Breath Questionnaire (SOBQ), after controlling for potential confounders including age, gender, FEV₁ (% predicted), DL_CO (% predicted), and the Beck Depression Inventory (BDI).

Results

Anxiety was significantly associated with worse functional capacity [6 MWD (B = -0.944, p < .001), ergometry peak workload (B = -.087, p = .04)], quality of life (B = .172, p < .001) and shortness of breath (B = .180, p < .001). Regression coefficients show that a 10 point increase in anxiety score is associated with a mean decrease in 6 MWD of 9 meters, a 1 Watt decrease in peak exercise workload, and an increase of almost 2 points on both the SGRQ and SOBQ.

Conclusion

In clinically stable patients with moderate to severe emphysema, anxiety is associated with worse exercise performance, quality of life and shortness of breath, after accounting for the influence of demographic and physiologic factors known to affect these outcomes.

Trail Registration

ClinicalTrials.gov NCT00000606

Accuracy of emphysema quantification performed with reduced numbers of CT sections

OBJECTIVE

The purpose of this study was to assess the accuracy of emphysema measurements obtained from systematic samples of evenly spaced CT images compared with measurements obtained from the entire scan.

MATERIALS AND METHODS

Evenly spaced transverse sections from the CT studies of 136 heavy smokers who underwent screening for lung cancer in the National Lung Screening Trial and of 112 subjects who underwent imaging before lung volume reduction surgery were sampled retrospectively. The samples were acquired both by selection of specific numbers of evenly spaced images and by selection of images at specific distance intervals. The percentage of lung pixels with attenuation below specific thresholds was used as an emphysema index. The image sample error was determined as the difference in emphysema index between the image samples and the entire scan.

RESULTS

The largest absolute image sample errors in the National Lung Screening Trial cohort with image sample sizes of five, 10, and 20 were 2.2, 0.8, and 0.5 index percentage points, respectively, at 1-mm section thickness (-960 HU threshold), and 2.6, 1.1, and 0.5 index percentage points at 5-mm section thickness (-930 HU threshold). The largest errors in the lung volume reduction surgery cohort for image sample sizes of five and 10 were 5.6 and 2.3 index percentage points at 8- to 10-mm section thickness (-900 HU threshold). Image sample errors were equivalent for the two sampling methods.

CONCLUSION

Systematic sampling resulted in very small errors in emphysema quantification and may be useful for decreasing radiation exposure in clinical research studies of emphysema.