Survival in COPD: impact of lung dysfunction and comorbidities

Long-term outcomes in patients with COPD treated with non-invasive ventilation for acute hypercapnic respiratory failure

PURPOSE

Chronic Obstructive Lung Disease (COPD) remains a major cause of morbidity and mortality across the world. We evaluated survival over 9 years in a cohort of patients with COPD requiring acute inpatient non-invasive ventilation (NIV). We analyzed prognostic indices to evaluate if they were associated with mortality.

PATIENTS AND METHODS

We performed a retrospective chart review of all patients who were admitted to St. James's Hospital respiratory ward with COPD and acute hypercapnic respiratory failure who required NIV over a 12-month period and followed their outcomes over 9 years. We investigated the association between survival and potential prognostic variables using univariate analysis and multivariate Cox proportional hazards model. We evaluated the association between survival and the following parameters: age, gender, multiple admissions requiring NIV (> 1 admission in within 12 months of index presentation), home NIV use preadmission, initial arterial blood gas pH, days spent on NIV, serum albumin and serum albumin to serum CRP ratio at admission.

RESULTS

Ninety-nine patients with COPD and acute hypercapnic respiratory failure were identified over a 12-month period from January to December 2011. Survival at 1, 2, 5 and 9 years was 65% (n = 64), 42% (n = 42), 25% (n = 25) and 21% (n = 21), respectively. Increasing age (p value < 0.001) and a lower serum albumin (p value < 0.005) were associated with a higher mortality. There was a trend towards improved survival in the group who were treated with home NIV prior to admission compared to no NIV therapy at home but this did not reach statistical significance (Fig. 3, p value = 0.088).

CONCLUSION

This study highlights the long-term mortality in patients with COPD admitted with hypercapnic respiratory failure requiring NIV and correlates with prior studies. Increasing age and lower serum albumin were associated with increased mortality. Home NIV may have a protective long-term survival benefit in patients with COPD who have been admitted for acute NIV.

Factors Affecting Survival in Severe and Very Severe COPD after Admission in ICUs of Tertiary Care Centers of India (FAST COPD): Study Protocol for a Multicentric Cohort Study

Background

Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity and mortality worldwide. However, there is a lack of comprehensive data from low- and middle-income countries (LMICs) regarding factors influencing COPD outcomes, particularly in regions where biomass exposure is prevalent.

Objective

The Factors Affecting Survival in Severe and Very Severe COPD Patients Admitted to Tertiary Centers of India (FAST) study aims to address this gap by evaluating factors impacting survival and exacerbation rates among COPD patients in LMICs like India, with a specific focus on biomass exposure, clinical phenotypes, and nutritional status in patients admitted to the Intensive Care Unit (ICU).

Methods

The FAST study is an observational cohort study conducted in university teaching hospitals across India. The study aims to enroll 1000 COPD patients admitted to the ICU meeting specific inclusion criteria, with follow-up assessments conducted every 6 months over a 2-year period. Data collection includes demographic information, clinical manifestations, laboratory investigations, pulmonary function tests, medications, nutritional status, mental health, and health-related quality of life. Adjudication of exacerbations and mortality will also be undertaken. The FAST study seeks to provide crucial insights into COPD outcomes in LMICs, informing more precise management strategies and mitigating the burden of COPD in these settings. By evaluating factors such as biomass exposure, clinical phenotypes, and nutritional status, the study aims to address key knowledge gaps in COPD research.

How to cite this article

Arunachala S, Devapal S, Swamy DSN, Greeshma MV, Ul Hussain I, Siddaiah JB, et al. Factors Affecting Survival in Severe and Very Severe COPD after Admission in ICUs of Tertiary Care Centers of India (FAST COPD): Study Protocol for a Multicentric Cohort Study. Indian J Crit Care Med 2024;28(6):552-560.

The six-minute step test can predict COPD exacerbations: a 36-month follow-up study

The six-minute step test (6MST) has been shown to be effective in assessing exercise capacity in individuals with COPD regardless of severity and, despite its easy execution, accessibility and validity, information on the prognostic power of this test remains uncertain. The aim of this study is to investigate whether the 6MST can predict the occurrence of exacerbations in patients with COPD. This is a prospective cohort study with a 36-month follow-up in patients with COPD. All patients completed a clinical assessment, followed by pulmonary function testing and a 6MST. The 6MST was performed on a 20 cm high step; heart rate, blood pressure, oxygen saturation, BORG dyspnea and fatigue were collected. Sixty-four patients were included in the study, the majority being elderly men. Performance on the 6MST demonstrated lower performance compared to normative values proposed in the literature, indicating a reduced functional capacity. Kaplan Meier analysis revealed that ≤ 59 steps climbed during the 6MST was a strong predictor of COPD exacerbation over a 36-month follow-up. We have identified a minimal threshold number of steps (≤ 59) obtained through the 6MST may be able predict the risk of exacerbations in patients with COPD.

Survival Analysis of COPD Patients in a 13-Year Nationwide Cohort Study of the Brazilian National Health System

BACKGROUND

Chronic obstructive pulmonary disease (COPD) has an appreciable socioeconomical impact in low- and middle-income countries, but most epidemiological data originate from high-income countries. For this reason, it is especially important to understand survival and factors associated with survival in COPD patients in these countries.

OBJECTIVE

To assess survival of COPD patients in Brazil, to identify risk factors associated with overall survival, including treatment options funded by the Brazilian National Health System (SUS).

METHODOLOGY

We built a retrospective cohort study of patients dispensed COPD treatment in SUS, from 2003 to 2015 using a National Database created from the record linkage of administrative databases. We further matched patients 1:1 based on sex, age and year of entry to assess the effect of the medicines on patient survival. We used the Kaplan-Meier method to estimate overall survival of patients, and Cox's model of proportional risks to assess risk factors.

RESULT

Thirty seven thousand and nine hundred and thirty eight patients were included. Patient's survival rates at 1 and 10 years were 97.6% (CI 95% 97.4-97.8) and 83.1% (CI 95% 81.9-84.3), respectively. The multivariate analysis showed that male patients, over 65 years old and underweight had an increased risk of death. Therapeutic regimens containing a bronchodilator in a free dose along with a fixed-dose combination of corticosteroid and bronchodilator seem to be a protective factor when compared to other regimens.

CONCLUSION

Our findings contribute to the knowledge of COPD patients' profile, survival rate and related risk factors, providing new evidence that supports the debate about pharmacological therapy and healthcare of these patients.

Risk of all-cause mortality associated with chronic obstructive pulmonary disease and the role of healthy ageing trajectories: a population-based study of middle-aged and older adults

OBJECTIVES

The aims were to study the risk of all-cause mortality associated with chronic obstructive pulmonary disease (COPD) and healthy ageing trajectories (HAT) in three birth cohorts and to determine the moderating role of HAT in the association between COPD and all-cause mortality.

DESIGN

Prospective cohort study.

SETTING

Data from waves 1 to 5 of The Survey of Health, Ageing and Retirement in Europe.

PARTICIPANTS

The total sample was 28 857 community-dwelling individuals aged 50+ years.

MAIN OUTCOME

All-cause mortality associated with COPD and HAT adjusting for covariates. We performed Aalen additive hazards models to explore these associations. Interactions between COPD and HAT were also explored. Analyses were conducted separately in three birth cohorts (>1945, 1936-1945 and ≤1935). Latent class growth analysis was used to classify participants into HAT.

RESULTS

Three parallel HAT were found in the three birth cohorts ('low', 'medium' and 'high' healthy ageing). Participants with COPD had an increased mortality risk, but this effect was no longer significant after adjusting for covariates. The 'low' HAT was associated with increased mortality risk in the three subsamples, although this effect was lower after adjustment. The interaction between COPD and HAT was significant only in the ≤1935 birth cohort, indicating that those with COPD and a 'low' trajectory had a greater risk of mortality.

CONCLUSIONS

The healthy ageing scale may be a suitable tool to identify patients at higher risk to mitigate disease burden and improve patients' quality of life.

Upper airway symptoms associate with the eosinophilic phenotype of COPD

BACKGROUND

There is growing evidence that upper airway symptoms coexist with lower airway symptoms in COPD. Still, the prevalence and impact of upper airway disease on the nature and course of COPD remain unclear. We aimed to describe this in a cross-sectional study.

METHODS

We examined a cohort of COPD patients with pulmonary function tests, induced sputum, blood eosinophils, atopy tests and computed tomography (CT) of the paranasal sinuses. Lower airway symptoms were assessed using the COPD Assessment Test (CAT), and upper airway symptoms were assessed using the nasal subdomain of the 22-item Sino Nasal Outcome Test (SNOT22nasal). We recruited patients from five sites in Denmark and Sweden. We excluded patients with a history of asthma.

FINDINGS

In total, 180 patients (female 55%, age 67±8 years, forced expiratory volume in 1 s (FEV1 %) 52.4±16.6, Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage: A: 18%, B: 54%, C: 3%, D: 25%) were included in the study. Seventy-four patients (41%) reported high upper airway symptoms (UAS, defined as SNOT22nasal≥6) with a median score of 10 (IQR 8-13). Patients with high UAS reported higher CAT scores (17.4±7.5 versus 14.9±6.6, p<0.05) and displayed higher fractions of eosinophils in blood (median 3.0% (IQR 1.6-4.2%) versus 2.3% (IQR 1.4-3.1%), p<0.05) and in induced sputum (median 1.8% (IQR 0.3-7.1%) versus median 0.5% (IQR 0-1.7%), p<0.05). No differences in atopy, CT findings or exacerbation rates were observed.

CONCLUSION

COPD patients with upper airway disease showed increased evidence of eosinophilic disease and increased lower airway symptom burden.

Quality of Life and Limitations in Daily Life of Stable COPD Outpatients in a Real-World Setting in Austria - Results from the CLARA Project

Background

COPD patients suffer from respiratory symptoms and limitations in daily life. We aimed to characterize the impact of disease on overall health, daily life, and perceived well-being in COPD outpatients.

Methods

We conducted a national, cross-sectional study among pulmonologists and general practitioners (GPs). The St. George’s Respiratory Questionnaire for COPD patients (SGRQ-C) was used. Inclusion criteria were a physician’s diagnosis of COPD and age ≥40 years. Subjects with a history of lung surgery, lung cancer or COPD exacerbation within the last four weeks were excluded.

Results

Sixty-seven pulmonologists and 6 GPs enrolled 1175 COPD patients. Two hundred forty-eight of those did not fulfill GOLD criteria for COPD (FEV₁/FVC <0.7) and 77 were excluded due to missing data. Finally, 850 patients (62.8% men; mean age 66.2 ± 0.3 (SE) years; mean FEV₁%pred. 51.5 ± 0.6 (SE)) were analyzed. Last year, 55.4% reported at least one exacerbation, and 12.7% were hospitalized for COPD exacerbation. Mean SGRQ-C total score was 43.1 ± 0.83 (SE) and mean component scores for symptoms, activity and impacts were 55.6, 55.4 and 30.5, respectively. Half of the patients (50.3%) reported not being able to do any sports and 78.7% stated that their respiratory symptoms did not allow them doing anything they would like to do. In patients with less severe COPD (FEV₁pred ≥50% and non-frequent exacerbations), global health status was overrated, ie, estimated as better by the physician than by the patient, while it was underrated in more severe COPD.

Conclusion

In Austria, the burden of disease in COPD outpatients tends to be underestimated in patients with milder airway obstruction and less exacerbations and overestimated in patients with more severe airway obstruction and frequent exacerbations. Our finding suggests that validated assessment of global health status might decrease these differences of perception.

Impact of Comorbidities and Commonly Used Drugs on Mortality in COPD - Real-World Data from a Primary Care Setting

Background

Life expectancy is significantly shorter for patients with chronic obstructive pulmonary disease (COPD) than the general population. Concurrent diseases are known to infer an increased mortality risk in those with COPD, but the effects of pharmacological treatments on survival are less established. This study aimed to examine any associations between commonly used drugs, comorbidities and mortality in Swedish real-world primary care COPD patients.

Methods

Patients with physician-diagnosed COPD from a large primary care population were observed retrospectively, utilizing primary care records and mandatory Swedish national registers. The time to all-cause death was assessed in a stepwise multiple Cox proportional hazards regression model including demography, socioeconomic factors, exacerbations, comorbidities and medication.

Results

During the observation period (1999-2009) 5776 (32.5%) of 17,745 included COPD patients died. Heart failure (hazard ratio [HR]: 1.88, 95% confidence interval [CI]: 1.74-2.04), stroke (HR: 1.52, 95% CI: 1.40-1.64) and myocardial infarction (HR: 1.40, 95% CI: 1.24-1.58) were associated with an increased risk of death. Use of inhaled corticosteroids (ICS; HR: 0.79, 95% CI: 0.66-0.94), beta-blockers (HR: 0.86, 95% CI: 0.76-0.97) and acetylsalicylic acid (ASA; HR: 0.87, 95% CI: 0.77-0.98) was dose-dependently associated with a decreased risk of death, whereas use of long-acting muscarinic antagonists (LAMA; HR: 1.33, 95% CI: 1.14-1.55) and N-acetylcysteine (NAC; HR: 1.26, 95% CI: 1.08-1.48) were dose-dependently associated with an increased risk of death in COPD patients.

Conclusion

This large, retrospective, observational study of Swedish real-world primary care COPD patients indicates that coexisting heart failure, stroke and myocardial infarction were the strongest predictors of death, underscoring the importance of timely recognition and treatment of comorbidities. A decreased risk of death associated with the use of ICS, beta-blockers and ASA, and an increased risk associated with the use of LAMA and NAC, was also found.

Low miR-150-5p and miR-320b Expression Predicts Reduced Survival of COPD Patients

Chronic obstructive pulmonary disease (COPD) is associated with an increased risk of death, reducing life expectancy on average between 5 and 7 years. The survival time after diagnosis, however, varies considerably as a result of the heterogeneity of COPD. Therefore, markers that predict individual survival of COPD patients are of great value. We analyzed baseline molecular profiles and collected 54 months of follow-up data of the cohort study “COPD and SYstemic consequences-COmorbidities NETwork” (COSYCONET). Genome-wide microRNA signatures from whole blood collected at time of the inclusion in the study were generated for 533 COPD patients including patients that deceased during the 54-month follow-up period (n = 53) and patients that survived this period (n = 480). We identified two blood-born microRNAs (miR-150-5p and miR-320b) that were highly predictive for survival of COPD patients. The expression change was then confirmed by RT-qPCR in 245 individuals. Ninety percent of patients with highest expression of miR-150-5p survived the 54-month period in contrast to only 50% of patients with lowest expression intensity. Moreover, the abundance of the oncogenic miR-150-5p in blood of COPD patients was predictive for the development of cancer. Thus, molecular profiles measured at the time of a COPD diagnosis have a high predictive power for the survival of patients.

[Chronic obstructive pulmonary disease and cardiovascular comorbidity]

In recent years, a greater understanding of the heterogeneity and complexity of chronic obstructive pulmonary disease (COPD) has come from the point of view of an integrated clinical assessment of severity, pathophysiology, and the relationship with other pathologies. A typical COPD patient suffers on average 4 or more concomitant diseases and every day about a third of patients take from 5 to 10 different drugs. The mechanisms of the interaction of COPD and cardiovascular disease (CVD) include the effects of systemic inflammation, hyperinflation (hyperinflation) of the lungs and bronchial obstruction. The risk of developing CVD in patients with COPD is on average 2-3 times higher than in people of a comparable age in the general population, even taking into account the risk of smoking. The prevalence of coronary heart disease, heart failure, and rhythm disturbances among COPD patients is significantly higher than in the general population. The article discusses in detail the safety of prescribing various groups of drugs for the treatment of CVD in patients with COPD. Achieving success in understanding and managing patients with COPD and CVD is possible using an integrated multidisciplinary approach.

Genome-Wide Association Analysis of Single-Breath DlCO

DlCO is a widely used pulmonary function test in clinical practice and a particularly useful measure for assessing patients with chronic obstructive pulmonary disease (COPD). We hypothesized that elucidating genetic determinants of DlCO could lead to better understanding of the genetic architecture of COPD. We estimated the heritability of DlCO using common genetic variants and performed genome-wide association analyses in four cohorts enriched for subjects with COPD (COPDGene [Genetic Epidemiology of COPD], NETT [National Emphysema Treatment Trial], GenKOLS [Genetics of Chronic Obstructive Lung Disease study], and TESRA [Treatment of Emphysema With a Gamma-Selective Retinoid Agonist study]) using a combined European ancestry white dataset and a COPDGene African American dataset. We assessed our genome-wide significant and suggestive associations for DlCO in previously reported genome-wide association studies of COPD and related traits. We also characterized associations of known COPD-associated variants and DlCO. We estimated the SNP-based heritability of DlCO in the European ancestry white population to be 22% (P = 0.0004). We identified three genome-wide significant associations with DlCO: variants near TGFB2, CHRNA3, and PDE11A loci (P < 5 × 10-8). In addition, 12 loci were suggestively associated with DlCO in European ancestry white (P < 1 × 10-5 in the combined analysis and P < 0.05 in both COPDGene and GenKOLS), including variants near NEGR1, CADM2, PCDH7, RETREG1, DACT2, NRG1, ANKRD18A, KRT86, NTN4, ARHGAP28, INSR, and PCBP3. Some DlCO-associated variants were also associated with COPD, emphysema, and/or spirometric values. Among 25 previously reported COPD loci, TGFB2, CHRNA3/CHRNA5, FAM13A, DSP, and CYP2A6 were associated with DlCO (P < 0.001). We identified several genetic loci that were significantly associated with DlCO and characterized effects of known COPD-associated loci on DlCO. These results could lead to better understanding of the heterogeneous nature of COPD.

Left ventricular volume and wall stress are linked to lung function impairment in COPD

BACKGROUND

Cardiovascular comorbidities are common in chronic obstructive pulmonary disease (COPD). We examined the association between airflow limitation, hyperinflation and the left ventricle (LV).

METHODS

Patients from the COPD cohort COSYCONET underwent evaluations including forced expiratory volume in 1 s (FEV₁), forced vital capacity (FVC), effective airway resistance (R_eff), intrathoracic gas volume (ITGV), and echocardiographic LV end-diastolic volume (LVEDV), stroke volume (LVSV), end-systolic volume (LVESV), and end-diastolic and end-systolic LV wall stress. Data from Visit 1 (baseline) and Visit 3 (18 months later) were used. In addition to comparisons of both visits, multivariate regression analysis was conducted, followed by structural equation modelling (SEM) with latent variables "Lung" and "Left heart".

RESULTS

A total of 641 participants were included in this analysis. From Visit 1 to Visit 3, there were significant declines in FEV₁ and FEV₁/FVC, and increases in R_eff, ITGV and LV end-diastolic wall stress, and a borderline significant decrease in LV mass. There were significant correlations of: FEV₁% predicted with LVEDV and LVSV; R_eff with LVSV; and ITGV with LV mass and LV end-diastolic wall stress. The SEM fitted the data of both visits well (comparative fit index: 0.978, 0.962), with strong correlation between "Lung" and "Left heart".

CONCLUSIONS

We demonstrated a relationship between lung function impairment and LV wall stress in patients with COPD. This supports the hypothesis that LV impairment in COPD could be initiated or promoted, at least partly, by mechanical factors exerted by the lung disorder.

Association of the IL-13 polymorphisms rs1800925 and rs20541 with chronic obstructive pulmonary disease risk: An updated meta-analysis

The aim of this study was to investigate if 2 common single nucleotide polymorphisms (SNPs) in the interleukin-13 (IL-13) gene, rs1800925 and rs20541 are associated with chronic obstructive pulmonary disease (COPD) risk.Case-control association studies were retrieved systematically from PubMed, Scopus, ISI Web of Science, China National Knowledge Infrastructure, and Wanfang databases using standardized subject terms.Eleven studies including 3077 participants (1896 cases and 1181 controls) were analyzed. Evidence for a positive association between the T allele of the IL-13 SNP rs1800925 and COPD risk was found in the overall population (odds ratio [OR] = 1.57, 95% confidence interval [95% CI]: 1.21-2.04, Pz = .001). In subgroup analysis according to ethnicity, the T allele of rs1800925 was associated with an increased risk of COPD in Asians (OR = 1.88, 95% CI: 1.23-2.87, Pz = .004) and Caucasians (OR = 1.30, 95% CI: 1.01-1.67, Pz = .041), respectively. For rs20541, the results suggested an association between rs20541 and COPD risk in Caucasians under the recessive model (OR = 2.79, 95% CI: 1.13-6.92, Pz = .026), whereas this SNP was not associated with COPD in Asians.This meta-analysis suggests that the T allele of rs1800925 is associated with the increased risk of COPD in both Asians and Caucasians, whereas rs20541 is associated with the risk of COPD in Caucasians but not in Asians.

Chronic Obstructive Pulmonary Disease and Cardiac Diseases. An Urgent Need for Integrated Care

Chronic obstructive pulmonary disease (COPD) is a global health issue with high social and economic costs. Concomitant chronic cardiac disorders are frequent in patients with COPD, likely owing to shared risk factors (e.g., aging, cigarette smoke, inactivity, persistent low-grade pulmonary and systemic inflammation) and add to the overall morbidity and mortality of patients with COPD. The prevalence and incidence of cardiac comorbidities are higher in patients with COPD than in matched control subjects, although estimates of prevalence vary widely. Furthermore, cardiac diseases contribute to disease severity in patients with COPD, being a common cause of hospitalization and a frequent cause of death. The differential diagnosis may be challenging, especially in older and smoking subjects complaining of unspecific symptoms, such as dyspnea and fatigue. The therapeutic management of patients with cardiac and pulmonary comorbidities may be similarly challenging: bronchodilators may have cardiac side effects, and, vice versa, some cardiac medications should be used with caution in patients with lung disease. The aim of this review is to summarize the evidence of the relationship between COPD and the three most frequent and important cardiac comorbidities in patients with COPD: ischemic heart disease, heart failure, and atrial fibrillation. We have chosen a practical approach, first summarizing relevant epidemiological and clinical data, then discussing the diagnostic and screening procedures, and finally evaluating the impact of lung-heart comorbidities on the therapeutic management of patients with COPD and heart diseases.

Chronic Obstructive Pulmonary Disease and the Risk of Stroke

RATIONALE

Chronic obstructive pulmonary disease (COPD) has been identified as a risk factor for cardiovascular diseases such as myocardial infarction. The role of COPD in cerebrovascular disease is, however, less certain. Although earlier studies have suggested that the risk for stroke is also increased in COPD, more recent investigations have generated mixed results.

OBJECTIVES

The primary objective of our review was to quantify the magnitude of the association between COPD and stroke. We also sought to clarify the nature of the relationship between COPD and stroke by investigating whether the risk of stroke in COPD varies with age, sex, smoking history, and/or type of stroke and whether stroke risk is modified in particular COPD phenotypes.

RESULTS

The MEDLINE and EMBASE databases were searched in May 2016 to identify articles that compared stroke outcomes in people with and without COPD. Studies were grouped by study design to distinguish those that reported prevalence of stroke (cross-sectional studies) from those that estimated incidence (cohort or case-control studies). In addition, studies were stratified according to study population characteristics, the nature of COPD case definitions, and adjustment for confounding (smoking). Heterogeneity was assessed using the I2 statistic. We identified 5,493 studies, of which 30 met our predefined inclusion criteria. Of the 25 studies that reported prevalence ratios, 11 also estimated prevalence odds ratios. The level of heterogeneity among the included cross-sectional studies did not permit the calculation of pooled ratios, save for a group of four studies that estimated prevalence odds ratios adjusted for smoking (prevalence odds ratio, 1.51; 95% confidence interval, 1.09-2.09; I2 = 45%). All 11 studies that estimated relative risk for nonfatal incident stroke reported increased risk in COPD. Adjustment for smoking invariably reduced the magnitude of the associations.

CONCLUSIONS

Although both prevalence and incidence of stroke are increased in people with COPD, the weight of evidence does not support the hypothesis that COPD is an independent risk factor for stroke. The possibility remains that COPD is causal in certain subsets of patients with COPD and for certain stroke subtypes.

Body height as risk factor for emphysema in COPD

Pulmonary emphysema is a phenotypic component of chronic obstructive pulmonary disease (COPD) which carries substantial morbidity and mortality. We explored the association between emphysema and body height in 726 patients with COPD using computed tomography as the reference diagnostic standard for emphysema. We applied univariate analysis to look for differences between patients with emphysema and those without, and multivariate logistic regression to identify significant predictors of the risk of emphysema. As covariates we included age, sex, body height, body mass index, pack-years of smoking, and forced expiratory volume in one second (FEV₁) as percent predicted. The overall prevalence of emphysema was 52%. Emphysemic patients were significantly taller and thinner than non-emphysemic ones, and featured significantly higher pack-years of smoking and lower FEV₁ (P < 0.001). The prevalence of emphysema rose linearly by 10-cm increase in body height (r² = 0.96). In multivariate analysis, the odds of emphysema increased by 5% (95% confidence interval, 3 to 7%) along with one-centimeter increase in body height, and remained unchanged after adjusting for all the potential confounders considered (P < 0.001). The odds of emphysema were not statistically different between males and females. In conclusion, body height is a strong, independent risk factor for emphysema in COPD.

COPD patients with severe diffusion defect in carbon monoxide diffusing capacity predict a better outcome for pulmonary rehabilitation

PURPOSE

The aim of this study was to compare the effects of pulmonary rehabilitation (PR) on six-minute walk test (6mWT) between chronic obstructive pulmonary disease (COPD) patients with moderate or severe carbon monoxide diffusion defects. We also evaluated dyspnea sensation, pulmonary functions, blood gases analysis, quality of life parameters and psychological symptoms in both groups before and after pulmonary rehabilitation.

METHODS

Patients with COPD underwent a comprehensive 8-week out-patient PR program participated in this study. Patients grouped according to diffusion capacity as moderate or severe. Outcome measures were exercise capacity (6mWT), dyspnea sensation, pulmonary function tests, blood gases analysis, quality of life (QoL) and psychological symptoms.

RESULTS

A total of 68 patients enrolled in the study. Thirty-two (47%) of them had moderate diffusion defect [Tl_CO; 52 (47-61)mmol/kPa] and 36 (53%) of them had severe diffusion defect [Tl_CO; 29 (22-34)mmol/kPa]. At the end of the program, PaO₂ (p=0.001), Modified Medical Research Council dyspnea scale (p=0.001), 6mWT (p<0.001) and quality of life parameters improved significantly in both groups (p<0.05). Also the improvement in Dl_CO (p=0.04) value and FEV₁% (p=0.01) reached a statistically significant level in patients with severe diffusion defect. When comparing changes between groups, dyspnea reduced significantly in patients with severe diffusion defect (p=0.04).

CONCLUSION

Pulmonary rehabilitation improves oxygenation, severity of dyspnea, exercise capacity and quality of life independent of level of carbon monoxide diffusion capacity in patents with COPD. Furthermore pulmonary rehabilitation may improve Dl_CO values in COPD patients with severe diffusion defect.

Relationship Among Chlamydia and Mycoplasma Pneumoniae Seropositivity, IKZF1 Genotype and Chronic Obstructive Pulmonary Disease in A General Japanese Population: The Nagahama Study

Chronic obstructive pulmonary disease (COPD) is a possible risk factor for cardiovascular disease. The association of COPD with the pathogenicity of infection with Chlamydia pneumoniae and Mycoplasma pneumoniae is controversial. We conducted a cross-sectional study to clarify the association between atypical pneumoniae seropositivity and COPD in a general population. We also investigated genetic polymorphisms conferring susceptibility to a pneumonia titer. The study included 9040 Japanese subjects (54 ± 13 years). COPD was defined as a ratio of forced expiratory volume in 1 second to forced vital capacity of less than 70%. Serum levels of IgA and IgG antibodies to C pneumoniae were determined using an enzyme-linked immunoassay, and M pneumoniae seropositivity was assessed by a particle agglutination test. Subjects seropositive for C pneumoniae (26.1%) had a higher prevalence of COPD (seropositive, 5.8%; seronegative, 3.1%; P < 0.001) after adjustment for age, sex, height, weight, and smoking status. The association between M pneumoniae seropositivity (20.4%) and COPD was also significant in covariate-adjusted analysis (P < 0.001). A genome-wide association analysis of the C pneumoniae IgA index identified a susceptible genotype (rs17634369) near the IKZF1 gene, and the seropositive rate of C pneumoniae significantly differed among genotypes (AA, 22.5; AG, 25.3; GG, 29.7%, P < 0.001). On multiple regression analysis, seropositivity for both C pneumoniae (odds ratio = 1.41, P = 0.004) and M pneumoniae (odds ratio = 1.60, P = 0.002) was an independent determinant for COPD, while no direct association was found with the rs17634369 genotype. Seropositivity for both C pneumoniae and M pneumoniae is an independent risk factor for COPD in the general population.

Mortality Outcomes of Patients with Chronic Kidney Disease and Chronic Obstructive Pulmonary Disease

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is associated with higher mortality in the general population. We studied the associations between COPD and death among chronic kidney disease (CKD) patients along with reporting cause-specific death data.

METHODS

We included 56,960 patients with stages 3 and 4 CKD who were followed in a large health care system. Associations between COPD and all-cause mortality and various causes of death (respiratory deaths, cardiovascular deaths, malignancy-related deaths and deaths due to other reasons) were studied using the Cox proportional hazards and competing risk models.

RESULTS

Out of 56,960 CKD patients, 4.7% (n = 2,667) had underlying COPD. Old age, presence of diabetes, hypertension, coronary artery disease, congestive heart failure, and smoking were associated with higher risk for COPD. During a median follow-up of 3.7 years, 15,969 patients died. After covariate adjustment, COPD was associated with a 41% increased risk (95% CI 1.31-1.52) for all-cause mortality, and fourfold increased risk (sub-hazard ratio 4.36, 95% CI 3.54-5.37) for respiratory-related deaths. In a sensitivity analysis that was performed by defining COPD as the use of relevant International Classification of Diseases-9 codes and medications used to treat COPD, similar results were noted.

CONCLUSIONS

COPD is associated with higher risk for death among those with CKD, and an underlying lung disease accounts for significant proportion of deaths. These data highlight the need for further prospective studies to understand the underlying mechanisms and potential interventions to improve outcomes in this population.

The effect of pulmonary rehabilitation on mortality, balance, and risk of fall in stable patients with chronic obstructive pulmonary disease

The aim of this study is to conduct a systematic review of published studies that evaluate the impact of pulmonary rehabilitation (PR) on survival and fall (including balance) in patients with chronic obstructive pulmonary disease at stability. OVID, Medline, EMBASE, and Cochrane collaboration library were searched for literature dating from January 1980 up to November 2014 as well as an update in October 2015. Two reviewers screened titles, abstracts and full text records, extracted data, and assessed studies for risk of bias; any disagreements were resolved by a third member of the team, and consensus was always sought. Initial searches yielded 3216 records but after review only seven studies were included and there were no studies focused solely on falls. Two cohort studies found some positive benefits of PR on balance, but the results were inconsistent across the studies. Regarding survival, two randomized controlled trials were conducted; one study showed significant survival benefit at 1 year, while the other one showed nonsignificant survival benefit at 3 years. Neither were adequately powered and in both, survival was a secondary outcome. There was only limited inconclusive evidence to show that PR has a significant beneficial effect on balance or survival.

Risk of cardiovascular comorbidity in patients with chronic obstructive pulmonary disease: a systematic review and meta-analysis

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a systemic inflammatory disorder associated with increased comorbid prevalence of cardiovascular diseases. We aimed to quantify the magnitudes of association between overall and specific types of cardiovascular disease, major cardiovascular risk factors, and COPD.

METHODS

We searched Cochrane, Medline, and Embase databases for studies published between Jan 1, 1980, and April 30, 2015, on the prevalence of cardiovascular disease and its risk factors in patients with COPD versus matched controls or random samples from the general public. We assessed associations with random-effects meta-analyses. We studied heterogeneity and biases with random-effects meta-regressions, jackknife sensitivity analyses, assessment of funnel plots, and Egger tests.

FINDINGS

We identified 18,176 unique references and included 29 datasets in the meta-analyses. Compared with the non-COPD population, patients with COPD were more likely to be diagnosed with cardiovascular disease (odds ratio [OR] 2·46; 95% CI 2·02-3·00; p<0·0001), including a two to five times higher risk of ischaemic heart disease, cardiac dysrhythmia, heart failure, diseases of the pulmonary circulation, and diseases of the arteries. Additionally, patients with COPD reported hypertension more often (OR 1·33, 95% CI 1·13-1·56; p=0·0007), diabetes (1·36, 1·21-1·53; p<0·0001], and ever smoking (4·25, 3·23-5·60; p<0·0001). The associations between COPD and these cardiovascular disease types and cardiovascular disease risk factors were consistent and valid across studies. Enrolment period, age, quality of data, and COPD diagnosis partly explained the heterogeneity.

INTERPRETATION

The coexistence of COPD, cardiovascular disease, and major risk factors for cardiovascular disease highlights the crucial need for the development of strategies to screen for and reduce cardiovascular risks associated with COPD.

FUNDING

Canadian Institutes of Health Research.