Cumulative occupational exposure to gases and fumes is associated with impairment in lung function and disease-related quality of life in a German COPD patient cohort.

OBJECTIVES: The impact of occupational exposures on lung function impairments and quality of life (QoL) in patients with chronic obstructive pulmonary disease (COPD) was analysed and compared with that of smoking. METHODS: Data from 1283 men and 759 women (Global Initiative for Chronic Obstructive Lung Disease (GOLD) grades 1-4 or former grade 0, without alpha-1-antitrypsin deficiency) of the COPD and Systemic Consequences Comorbidities Network cohort were analysed. Cumulative exposure to gases/fumes, biological dust, mineral dust or the combination vapours/gases/dusts/fumes was assessed using the ALOHA job exposure matrix. The effect of both occupational and smoking exposure on lung function and disease-specific QoL (St George's Respiratory Questionnaire) was analysed using linear regression analysis adjusting for age, body mass index, diabetes, hypertension and coronary artery disease, stratified by sex. RESULTS: In men, exposure to gases/fumes showed the strongest effects among occupational exposures, being significantly associated with all lung function parameters and QoL; the effects were partially stronger than of smoking. Smoking had a larger effect than occupational exposure on lung diffusing capacity (transfer factor for carbon monoxide) but not on air trapping (residual volume/total lung capacity). In women, occupational exposures were not significantly associated with QoL or lung function, while the relationships between lung function parameters and smoking were comparable to men. CONCLUSIONS: In patients with COPD, cumulative occupational exposure, particularly to gases/fumes, showed effects on airway obstruction, air trapping, gas uptake capacity and disease-related QoL, some of which were larger than those of smoking. These findings suggest that lung air trapping and QoL should be considered as outcomes of occupational exposure to gases and fumes in patients with COPD. TRIAL REGISTRATION NUMBER: NCT01245933.

[What have we learned from the German COPD cohort COSYCONET and where do we go from here?] / Was haben wir aus der deutschen COPD-Kohorte COSYCONET gelernt und wie geht es weiter?

COSYCONET 1 is the only German COPD cohort which is large enough to be internationally comparable. The recruitment, which started in 2010 and ended in December 2013, comprised 2741 patients with the diagnosis of COPD who were subsequently investigated in regular follow-up visits. All visits included a comprehensive functional and clinical characterisation. On the basis of this detailed data set, it was possible to address a large number of clinical questions. These questions ranged from the prescription of medication, the detailed analysis of comorbidities, in particular cardiovascular disease, and biomarker assessment to radiological and health-economic aspects. Currently, more than 60 publications of COSYCONET data are internationally available. The present overview provides a description of all the results that were obtained, focussing on the relationship between different clinical and functional aspects as well as their potential practical consequences. In addition, information on the follow-up study COSYCONET 2 is given.

The association of cognitive functioning as measured by the DemTect with functional and clinical characteristics of COPD: results from the COSYCONET cohort.

Alterations of cognitive functions have been described in COPD. Our study aimed to disentangle the relationship between the degree of cognitive function and COPD characteristics including quality of life (QoL).Data from 1969 COPD patients of the COSYCONET cohort (GOLD grades 1-4; 1216 male/ 753 female; mean (SD) age 64.9 ± 8.4 years) were analysed using regression and path analysis. The DemTect screening tool was used to measure cognitive function, and the St. George's respiratory questionnaire (SGRQ) to assess disease-specific QoL.DemTect scores were < 9 points in 1.6% of patients and < 13 points in 12% when using the original evaluation algorithm distinguishing between < 60 or > =60 years of age. For statistical reasons, we used the average of both algorithms independent of age in all subsequent analyses. The DemTect scores were associated with oxygen content, 6-min-walking distance (6-MWD), C-reactive protein (CRP), modified Medical Research Council dyspnoea scale (mMRC) and the SGRQ impact score. Conversely, the SGRQ impact score was independently associated with 6-MWD, FVC, mMRC and DemTect. These results were combined into a path analysis model to account for direct and indirect effects. The DemTect score had a small, but independent impact on QoL, irrespective of the inclusion of COPD-specific influencing factors or a diagnosis of cognitive impairment.We conclude that in patients with stable COPD lower oxygen content of blood as a measure of peripheral oxygen supply, lower exercise capacity in terms of 6-MWD, and higher CRP levels were associated with reduced cognitive capacity. Furthermore, a reduction in cognitive capacity was associated with reduced disease-specific quality of life. As a potential clinical implication of this work, we suggest to screen especially patients with low oxygen content and low 6-MWD for cognitive impairment.

Effect of COPD severity and comorbidities on the result of the PHQ-9 tool for the diagnosis of depression: results from the COSYCONET cohort study.

The diagnosis of depression, a frequent comorbidity of chronic obstructive pulmonary disease (COPD), is often supported by questionnaires, such as the Patient Health Questionnaire 9 (PHQ-9). It is unknown to which extent its single questions are affected by the clinical characteristics of COPD patients.We addressed this question in 2255 GOLD grade 1-4 patients from the COSYCONET (COPD and Systemic Consequences - Comorbidities Network) COPD cohort. The dependence on COPD severity was assessed using symptoms, exacerbation risk (GOLD A-D; modified Medical Research Council dyspnoea scale (mMRC)), and frequent comorbidities as predictors of PHQ-9 results, while including age, gender, body mass index (BMI) and smoking habits as covariates.Symptoms and exacerbation risk were associated with depression in an additive manner, with mean elevations in the PHQ-9 sum score by 2.75 and 1.44 points, respectively. Asthma, sleep apnoea, gastrointestinal disorders, osteoporosis and arthritis were linked to increases by 0.8 to 1.3 points. Overall, the COPD characteristics contributed to the mean PHQ-9 score by increases from 4.5 or 5.2 to 6.3 points, respectively, when either taking GOLD A as reference or the absence of comorbidities. This finding was independent of the diagnosis of mental disorder or the intake of antidepressants. The presence of COPD led to an increase in the proportion of scores indicating depression from 12 to 22%. Single item analysis revealed homogenous effects regarding GOLD groups, but heterogeneous effects regarding GOLD grades.These findings indicate specific effects of COPD severity on the PHQ-9 depression score, especially symptoms and exacerbation risk, explaining the high prevalence of depression in COPD. Alternative explanations like an overlap of COPD severity and PHQ-9 items are discussed. Of note, we also found COPD treatment effects on depression scores.

Transfer factor for carbon monoxide in patients with COPD and diabetes: results from the German COSYCONET cohort.

BACKGROUND: An impairment of CO diffusing capacity has been shown in diabetic patients without lung disease. We analyzed how diffusing capacity in patients with COPD is affected by the concurrent diagnosis of diabetes. METHODS: Data from the initial visit of the German COPD cohort COSYCONET were used for analysis. 2575 patients with complete lung function data were included, among them 358 defined as diabetics with a reported physician diagnosis of diabetes and/or specific medication. Pairwise comparisons between groups and multivariate regression models were used to identify variables predicting the CO transfer factor (TLCO%pred) and the transfer coefficient (KCO%pred). RESULTS: COPD patients with diabetes differed from those without diabetes regarding lung function, anthropometric, clinical and laboratory parameters. Moreover, gender was an important covariate. After correction for lung function, gender and body mass index (BMI), TLCO%pred did not significantly differ between patients with and without diabetes. The results for the transfer coefficient KCO were similar, demonstrating an important role of the confounding factors RV%pred, TLC%pred, ITGV%pred, FEV1%pred, FEV1/FVC, age, packyears, creatinine and BMI. There was not even a tendency towards lower values in diabetes. CONCLUSION: The analysis of data from a COPD cohort showed no significant differences of CO transport parameters between COPD patients with and without diabetes, if BMI, gender and the reduction in lung volumes were taken into account. This result is in contrast to observations in lung-healthy subjects with diabetes and raises the question which factors, among them potential anti-inflammatory effects of anti-diabetes medication are responsible for this finding.

Clinical factors linked to the type of respiratory medication in COPD: results from the COSYCONET cohort.

BACKGROUND: The use of maintenance medication in patients with chronic obstructive pulmonary disease (COPD) in real life is known to deviate from recommendations in guidelines, which are largely based on randomized controlled trials and selected populations. OBJECTIVES: We used the COSYCONET (COPD and Systemic Consequences - Comorbidities Network) cohort to analyze factors linked to the use of COPD drugs under non-interventional circumstances. DESIGN: COSYCONET is an ongoing, multi-center, non-interventional cohort of patients with COPD. METHODS: Patients with COPD of Global Initiative for Chronic Obstructive Lung Disease (GOLD) grades 0-4 participating in visits 1-5 were included. Data covered the period from 2010 to 2018. Generalized linear models were used to examine the relation of COPD characteristics to different types of respiratory medication. RESULTS: A total of 1043 patients were included. The duration of observation was 4.5 years. Use of respiratory medication depended on GOLD grades 0-4 and groups A-D. Long-acting muscarinic antagonist therapy increased over time, and was associated with low carbon monoxide (CO) diffusing capacity, while inhaled corticosteroid (ICS) use decreased. Active smoking was associated with less maintenance therapy in general, and female sex with less ICS use. From the eight items of the COPD Assessment Test, only hill and stair climbing were consistently linked to treatment. CONCLUSION: Using data from a large, close to real-life observational cohort, we identified factors linked to the use of various types of respiratory COPD medication. Overall, use was consistent with GOLD recommendations. Beyond this, we identified other correlates of medication use that may help us to understand and improve therapy decisions in clinical practice. TRIAL REGISTRATION: ClinicalTrials.gov NCT01245933.

Characteristics of Current Smokers versus Former Smokers with COPD and Their Associations with Smoking Cessation Within 4.5 Years: Results from COSYCONET.

Background: Many patients with chronic obstructive pulmonary disease (COPD) continue smoking. We used data from the "real-life" COSYCONET COPD cohort to evaluate whether these patients differed from patients with COPD who either had ceased smoking prior to inclusion or ceased during the follow-up time of the study. Methods: The analysis was based on data from visits 1-5 (covering 4.5 years), including all patients with the diagnosis of COPD who were either ex-smokers or smokers and categorized as GOLD 1-4 or the former GOLD 0 category. We compared the characteristics of smokers and ex-smokers at baseline (visit 1), as well as the course of lung function in the follow-up of permanent ex-smokers, permanent smokers and incident ex-smokers (smokers at visit 1 who ceased smoking before visit 5). We also identified baseline factors associated with subsequent smoking cessation. Results: Among 2500 patients who were ever-smokers, 660 were current smokers and 1840 ex-smokers at baseline. Smokers were younger than ex-smokers (mean 61.5 vs 66.0 y), had a longer duration of smoking but fewer pack-years, a lower frequency of asthma, higher forced expiratory volume in 1 sec (FEV1, 59.4 vs 55.2% predicted) and higher functional residual capacity (FRC, 147.7 vs 144.3% predicted). Similar results were obtained for the longitudinal subpopulation, comprising 713 permanent ex-smokers, 175 permanent smokers, and 55 incident ex-smokers. When analyzing the time course of lung function, higher FRC, lower FEV1 and the presence of asthma (p < 0.05 each) were associated with incident cessation prior to visit 5, while less airway obstruction was associated with smoking continuation. Conclusion: These findings, which were consistent in the cross-sectional and longitudinal analyses, suggest that lung hyperinflation was associated with being or becoming ex-smoker. Possibly, it is perceived by patients as one of the factors motivating their attempts to quit smoking, independent from airway obstruction.

Disease Progression and Age as Factors Underlying Multimorbidity in Patients with COPD: Results from COSYCONET.

Background: Multimorbidity plays an important role in chronic obstructive pulmonary disease (COPD) but is also a feature of ageing. We estimated to what extent increases in the prevalence of multimorbidity over time are attributable to COPD progression compared to increasing patient age. Methods: Patients with COPD from the long-term COSYCONET (COPD and Systemic Consequences - Comorbidities Network) cohort with four follow-up visits were included in this analysis. At each visit, symptoms, exacerbation history, quality of life and lung function were assessed, along with the comorbidities heart failure (HF), coronary artery disease (CAD), peripheral arterial disease (PAD), hypertension, sleep apnea, diabetes mellitus, hyperlipidemia, hyperuricemia and osteoporosis. Using longitudinal logistic regression analysis, we determined what proportion of the increase in the prevalence of comorbidities could be attributed to patients' age or to the progression of COPD over visits. Results: Of 2030 patients at baseline, 878 completed four follow-up visits (up to 4.5 years). CAD prevalence increased over time, with similar effects attributable to the 4.5-year follow-up, used as indicator of COPD progression, and to a 5-year increase in patients' age. The prevalence of HF, diabetes, hyperlipidemia, hyperuricemia, osteoporosis and sleep apnea showed stronger contributions of COPD progression than of age; in contrast, age dominated for hypertension and PAD. There were different relationships to patients' characteristics including BMI and sex. The results were not critically dependent on the duration of COPD prior to enrolment, or the inclusion of patients with all four follow-up visits vs those attending only at least one of them. Conclusion: Analyzing the increasing prevalence of multimorbidity in COPD over time, we separated age-independent contributions, probably reflecting intrinsic COPD-related disease progression, from age-dependent contributions. This distinction might be useful for the individual assessment of disease progression in COPD.

Cardiovascular predictors of mortality and exacerbations in patients with COPD.

In chronic obstructive pulmonary disease (COPD), comorbidities and worse functional status predict worse outcomes, but how these predictors compare with regard to different outcomes is not well studied. We thus compared the role of cardiovascular comorbidities for mortality and exacerbations. Data from baseline and up to four follow-up visits of the COSYCONET cohort were used. Cox or Poisson regression was employed to determine the relationship of predictors to mortality or mean annual exacerbation rate, respectively. Predictors comprised major comorbidities (including cardiovascular disease), lung function (forced expiratory volume in 1 s [FEV1], diffusion capacity for carbon monoxide [TLCO]) and their changes over time, baseline symptoms, exacerbations, physical activity, and cardiovascular medication. Overall, 1817 patients were included. Chronic coronary artery disease (p = 0.005), hypertension (p = 0.044) and the annual decline in TLCO (p = 0.001), but not FEV1 decline, were predictors of mortality. In contrast, the annual decline of FEV1 (p = 0.019) but not that of TLCO or cardiovascular comorbidities were linked to annual exacerbation rate. In conclusion, the presence of chronic coronary artery disease and hypertension were predictors of increased mortality in COPD, but not of increased exacerbation risk. This emphasizes the need for broad diagnostic workup in COPD, including the assessment of cardiovascular comorbidity.Clinical Trials: NCT01245933.

Impact of the COVID-19 pandemic on the behaviour and health status of patients with COPD: results from the German COPD cohort COSYCONET.

BACKGROUND: Infection control measures for coronavirus disease 2019 (COVID-19) might have affected management and clinical state of patients with COPD. We analysed to which extent this common notion is fact-based. METHODS: Patients of the COSYCONET cohort were contacted with three recurring surveys (COVID1, 2 and 3 at 0, 3 and 6 months, respectively). The questionnaires comprised behaviour, clinical and functional state, and medical treatment. The responses to the questionnaires were compared amongst themselves and with pre-COVID information from the last visit of COSYCONET. RESULTS: Overall, 594 patients were contacted and 375 patients (58% males, forced expiratory volume in 1 s (FEV1) 61±22% predicted) provided valid data in COVID1 and COVID2. Five patients reported infections with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Most patients - except for patients with higher education - reported compliance with recommended protective measures, whereby compliance to hygiene, contact and access to physicians slightly improved between COVID1 and COVID2. Also, patients obtained more information from physicians than from public media. In the majority of cases, the personal physician could not be substituted by remote consultation. Over time, symptoms slightly increased and self-assessed physical capacity decreased. Results of COVID3 were similar. Women and patients with more exacerbations and dyspnoea avoided medical consultations, whereas Global Initiative for Chronic Obstructive Lung Disease (GOLD) D patients were more amenable to tele-consultation. CONCLUSION: In well-characterised COPD patients, we observed on average slight deteriorations of clinical state during the period of COVID-19 restrictions, with high and partially increasing adherence to protective measures. The data suggest that in particular, women and GOLD D patients should be actively contacted by physicians to identify deteriorations.