Treatment of COPD Groups GOLD A and B with inhaled corticosteroids in the COSYCONET cohort - determinants and consequences.

Background: In COPD patients of GOLD groups A and B, a high degree of treatment with inhaled corticosteroids (ICS) has been reported, which is regarded as overtreatment according to GOLD recommendations. We investigated which factors predict ICS use and which relationship it has to clinical and functional outcomes, or healthcare costs. Methods: We used pooled data from visits 1 and 3 of the COSYCONET cohort (n=2741, n=2053, interval 1.5 years) including patients categorized as GOLD grades 1-4 and GOLD group A or B at both visits (n=1080). Comparisons were performed using ANOVA, and regression analyses using propensity matching and inverse probability weighting to adjust for differences between ICS groups. These were defined as having ICS at both visits (always) vs no ICS at both visits (never). Measures were divided into predictors of ICS treatment and outcomes. Results: Among 1080 patients, 608 patients were eligible for ICS groups (n=297 never, n=311 always). Prior to matching, patients with ICS showed significantly (p<0.05 each) impaired lung function, symptoms and exacerbation history. After matching, the outcomes generic quality of life and CO diffusing capacity were increased in ICS patients (p<0.05 each). Moreover, costs for respiratory medication, but not total health care costs, were significantly elevated in the ICS group by 780€ per year. Conclusion: ICS therapy in COPD GOLD A/B patients can have small positive and negative effects on clinical outcomes and health care costs, indicating that the clinical evaluation of ICS over-therapy in COPD requires a multi-dimensional approach

Deterioration and mortality risk of COPD patients not fitting into standard GOLD categories: Results of the COSYCONET Cohort.

Background: Patients with COPD-specific symptoms and history but FEV1/FVC ratio ≥0.7 are a heterogeneous group (former GOLD grade 0) with uncertainties regarding natural history. Objective: We investigated which lung function measures and cutoff values are predictive for deterioration according to GOLD grades and all-cause mortality. Methods: We used visit 1-4 data of the COSYCONET cohort. Logistic and Cox regression analyses were used to identify relevant parameters. GOLD 0 patients were categorized according to whether they maintained grade 0 over the following 2 visits or deteriorated persistently into grades 1 or 2. Their clinical characteristics were compared with those of GOLD 1 and 2 patients. Results: Among 2,741 patients, 374 GOLD 0, 206 grade 1, and 962 grade 2 patients were identified. GOLD 0 patients were characterized by high symptom burden, comparable to grade 2, and a restrictive lung function pattern; those with FEV1/FVC above 0.75 were unlikely to deteriorate over time into grades 1 and 2, in contrast to those with values between 0.70 and 0.75. Regarding mortality risk in GOLD 0, FEV1%predicted and age were the relevant determinants, whereby a cutoff value of 65% was superior to that of 80% as proposed previously. Conclusions: Regarding patients of the former GOLD grade 0, we identified simple criteria for FEV1/FVC and FEV1% predicted that were relevant for the outcome in terms of deterioration over time and mortality. These criteria might help to identify patients with the typical risk profile of COPD among those not fulfilling spirometric COPD criteria

Gender-specific differences in COPD symptoms and their impact for the diagnosis of cardiac comorbidities.

Background: In chronic obstructive pulmonary disease (COPD), gender-specific differences in the prevalence of symptoms and comorbidity are known. Research question: We studied whether the relationship between these characteristics depended on gender and carried diagnostic information regarding cardiac comorbidities. Study design and methods: The analysis was based on 2046 patients (GOLD grades 1–4, 795 women; 38.8%) from the COSYCONET COPD cohort. Assessments comprised the determination of clinical history, comorbidities, lung function, COPD Assessment Test (CAT) and modified Medical Research Council dyspnea scale (mMRC). Using multivariate regression analyses, gender-specific differences in the relationship between symptoms, single CAT items, comorbidities and functional alterations were determined. To reveal the relationship to cardiac disease (myocardial infarction, or heart failure, or coronary artery disease) logistic regression analysis was performed separately in men and women. Results: Most functional parameters and comorbidities, as well as CAT items 1 (cough), 2 (phlegm) and 5 (activities), differed significantly (p < 0.05) between men and women. Beyond this, the relationship between functional parameters and comorbidities versus symptoms showed gender-specific differences, especially for single CAT items. In men, item 8 (energy), mMRC, smoking status, BMI, age and spirometric lung function was related to cardiac disease, while in women primarily age was predictive. Interpretation: Gender-specific differences in COPD not only comprised differences in symptoms, comorbidities and functional alterations, but also differences in their mutual relationships. This was reflected in different determinants linked to cardiac disease, thereby indicating that simple diagnostic information might be used differently in men and women. Clinical trial registration: The cohort study is registered on ClinicalTrials.gov with identifier NCT01245933 and on GermanCTR.de with identifier DRKS00000284, date of registration November 23, 2010. Further information can be obtained on the website http://www.asconet.net

Reduced decline of lung diffusing capacity in COPD patients with diabetes and metformin treatment.

We studied whether in patients with COPD the use of metformin for diabetes treatment was linked to a pattern of lung function decline consistent with the hypothesis of anti-aging effects of metformin. Patients of GOLD grades 1–4 of the COSYCONET cohort with follow-up data of up to 4.5 y were included. The annual decline in lung function (FEV1, FVC) and CO diffusing capacity (KCO, TLCO) in %predicted at baseline was evaluated for associations with age, sex, BMI, pack-years, smoking status, baseline lung function, exacerbation risk, respiratory symptoms, cardiac disease, as well as metformin-containing therapy compared to patients without diabetes and metformin. Among 2741 patients, 1541 (mean age 64.4 y, 601 female) fulfilled the inclusion criteria. In the group with metformin treatment vs. non-diabetes the mean annual decline in KCO and TLCO was significantly lower (0.2 vs 2.3, 0.8 vs. 2.8%predicted, respectively; p < 0.05 each), but not the decline of FEV1 and FVC. These results were confirmed using multiple regression and propensity score analyses. Our findings demonstrate an association between the annual decline of lung diffusing capacity and the intake of metformin in patients with COPD consistent with the hypothesis of anti-aging effects of metformin as reflected in a surrogate marker of emphysema

CAT score single item analysis in patients with COPD: Results from COSYCONET.

The COPD Assessment Test (CAT) is in widespread use for the evaluation of patients with chronic obstructive pulmonary disease (COPD). We assessed whether the CAT items carry additional information beyond the sum score regarding COPD characteristics including emphysema. Patients of GOLD grades 1 to 4 from the COPD cohort COSYCONET (German COPD and Systemic Consequences - Comorbidities Network) with complete CAT data were included (n = 2270), of whom 493 had chest CT evaluated for the presence of emphysema. Comorbidities and lung function were assessed following standardised procedures. Cross-sectional data analysis was based on multiple regression analysis of the single CAT items against a panel of comorbidities, lung function, or CT characteristics (qualitative score, 15th percentile of mean lung density), with age, BMI and gender as covariates. This was supported by exploratory factor analysis. Regarding the relationship to comorbidities and emphysema, there were marked differences between CAT items, especially items 1 and 2 versus 3 to 8. This grouping was basically confirmed by factor analysis. Items 4 and 5, and to a lower degree 1, 2 and 6, appeared to be informative regarding the presence of emphysema, whereas the total score was not or less informative. Regarding comorbidities, similar findings as for the total CAT score were obtained for the modified Medical Research Council scale (mMRC) which was also informative regarding emphysema. Our findings suggest that the usefulness of the CAT can be increased if evaluated on the basis of single items which may be indicating the presence of comorbidities and emphysema

Prediction of lung emphysema in COPD by spirometry and clinical symptoms: Results from COSYCONET.

Background: Lung emphysema is an important phenotype of chronic obstructive pulmonary disease (COPD), and CT scanning is strongly recommended to establish the diagnosis. This study aimed to identify criteria by which physicians with limited technical resources can improve the diagnosis of emphysema. Methods: We studied 436 COPD patients with prospective CT scans from the COSYCONET cohort. All items of the COPD Assessment Test (CAT) and the St George’s Respiratory Questionnaire (SGRQ), the modified Medical Research Council (mMRC) scale, as well as data from spirometry and CO diffusing capacity, were used to construct binary decision trees. The importance of parameters was checked by the Random Forest and AdaBoost machine learning algorithms. Results: When relying on questionnaires only, items CAT 1 & 7 and SGRQ 8 & 12 sub-item 3 were most important for the emphysema- versus airway-dominated phenotype, and among the spirometric measures FEV1/FVC. The combination of CAT item 1 (≤ 2) with mMRC (> 1) and FEV1/FVC, could raise the odds for emphysema by factor 7.7. About 50% of patients showed combinations of values that did not markedly alter the likelihood for the phenotypes, and these could be easily identified in the trees. Inclusion of CO diffusing capacity revealed the transfer coefficient as dominant measure. The results of machine learning were consistent with those of the single trees. Conclusions: Selected items (cough, sleep, breathlessness, chest condition, slow walking) from comprehensive COPD questionnaires in combination with FEV1/FVC could raise or lower the likelihood for lung emphysema in patients with COPD. The simple, parsimonious approach proposed by us might help if diagnostic resources regarding respiratory diseases are limited. Trial registration ClinicalTrials.gov, Identifier: NCT01245933, registered 18 November 2010, https://clinicaltrials.gov/ct2/show/record/NCT01245933