COPD and its comorbidities: New findings from the COSYCONET cohort study
Approximately 10% of all Germans above the age of 40 years suffer from chronic obstructive pulmonary disease. For this reason, the illness abbreviated “COPD” is one of the eight research areas examined in the DZL. Since 2016, the COPD cohort study COSYCONET has been part of the DZL. A number of results published by COSYCONET scientists this year increase our knowledge of COPD.
The cohort study COSYCONET (“German COPD and Systematic Consequences COmorbidities NETwork”) investigates how lung health, concomitant diseases and systemic inflammation in patients with chronic obstructive pulmonary disease (COPD) are related. Between 2010 and 2013, nearly 3,000 people with varying degrees of COPD participated in the survey. They completed an extensive research program at one of the 31 participating study centers. This included questionnaires on medical history, demographic factors and quality of life as well as a series of lung function measurements. In addition, the study teams examined physical fitness and cardiovascular system functions of the patients. The participants in the study donated blood and urine for later investigations. However, COSYCONET was not completed at this point for the patients. In order to study the long-term course of COPD, they have since been visiting their respective study center for follow-up examinations on a regular basis.
Behind COSYCONET stands a logistical masterpiece that begins with the planning of the visits. When the patients are at the study center, study assistants collect data, perform examinations and process the samples, which are then stored in a central biobank. After completion of the data check for the first visits, the evaluation has recently started. This has already led to a double-digit number of publications in scientific journals.
COSYCONET initially received direct funding from the Federal Ministry of Education and Research (BMBF) and has been an associate member of the DZL since 2016.
These are the results of the study during the year 2018:
• Often, COPD and cardiovascular diseases occur together. For this reason, Dr. Peter Alter from the University of Marburg and his colleagues investigated how airway obstruction, pulmonary hyperinflation and various cardiovascular readings correlate with each other. They found that cardiovascular problems often did not occur independently of COPD, but on the contrary probably could be alleviated by reducing airway obstruction and hyperinflation of the lung.1
• Another aspect of this connection was also examined by Peter Alter and colleagues. They found that there is an association between impaired lung function and stress of the left ventricular wall in patients who have no manifest heart disease. The mechanical stress caused by their COPD may lead to this. Therefore, the authors suggest that the cardiovascular system of COPD patients should be tested regularly preventively.2
• COPD patients often take several medications at the same time – especially because of their comorbidities. In the COSYCONET cohort, this relationship has been statistically examined amongst the elderly. In fact, COPD patients over the age of 65 on average take five different medications, three of which not targeting lung diseases. In a further analysis, the scientists found that in ten percent of patients unfavorable drug interactions can occur. However, they consider the proportion of drug interactions as low, given the number of different preparations that patients take.3
• In another study, scientists from all five DZL sites investigated whether the new so-called GOLD categorization of COPD patients into severity grades A-D could also be linked to comorbidities. In fact, this is the case: there is a correlation with the risk of developing certain comorbidities. For this reason, the authors consider the GOLD categorization to be clinically meaningful, not only for exacerbations (acute worsening), but also for concomitant diseases.4
• COPD can occur in two forms: the emphysema-dominated type or the airway-dominated type in which inflammation occurs. Mixed forms are also observed. Both forms can be well differentiated by computed tomography (CT). Their distinction is important, because it influences therapy. Since CT is associated with a certain radiation exposure, the current study by Dr. Kathrin Kahnert and colleagues clarifies to what extent lung function measurements can be used to determine the COPD type. The result is that a combination of lung function measurement and the carbon monoxide exchange capacity allows for a safe distinction.5
• Patients participating in the COSYCONET registry donate blood. Such samples have now been investigated in a cross-sectional study by Kathrin Kahnert and colleagues. It became apparent that the uric acid concentration in the blood is associated with certain disease symptoms. For example, patients with a high uric acid concentration have poorer lung function, a lower physical capacity and are prone to cardiovascular comorbidities. The researchers conclude that the uric acid concentration is a useful laboratory value, which allows conclusions about the disease status.6
• The authors of this study asked which medicines COPD patients are treated with and investigated whether this is done in accordance with the guidelines. Surprisingly, there were some pronounced deviations, especially in the treatment of exacerbations (acute worsening). Due to such, not guideline-equitable treatment can lead to suboptimal treatment successes or avoidable side effects.7
• Peter Alter and his co-authors examined the hyperinflation of the lungs. This common symptom of COPD results in poor gas exchange and a whole range of sequelae, e.g. reduced physical capacity. In overweight individuals, the remaining available lung capacity may be further reduced as the diaphragm, which is essential for respiration, is pushed upwards. The scientists found that certain models used to predict this residual capacity are imprecise because they overestimate the influence of body weight. This should be kept in mind by doctors performing pulmonary function measurements.8
1 Alter P, Watz H, Kahnert K, Pfeifer M, Randerath W, Andreas S, Waschki B, Kleibrink BE, Welte T, Bals R, Schulz H, Biertz F, Young D, Vogelmeier CF, Jörres RA (2018) Airway obstruction and lung hyperinflation in COPD are linked to an impaired left ventricular diastolic filling. Resp Med 137: 14–22 (Collaboration of the DZL sites ARCN, BREATH, CPC-M, UGMLC)
2 Alter P, Jörres RA, Watz H, Welte T, Gläser S, Schulz H, Bals R, Karch A, Wouters EF, Vestbo J, Young D, Vogelmeier CF (2018) Left ventricular volume and wall stress are linked to lung function impairment in COPD. Int J of Cardiol 261: 172–178 (Collaboration of the DZL sites ARCN, BREATH, CPC-M, UGMLC)
3 Graf J, Lucke T, Herrera R, Watz H, Holle R, Vogelmeier C, Ficker JH, Jörres RA. (2018) Compatibility of medication with PRISCUS criteria and identification of drug interactions in a large cohort of patients with COPD. Pulm Pharmacol Ther 49: 123-129 (Collaboration of the DZL sites ARCN, CPC-M, UGMLC)
4 Kahnert K, Alter P, Young D, Lucke T, Heinrich J, Huber RM, Behr J, Wacker M, Biertz F, Watz H, Bals R, Welte T, Wirtz H, Herth F,Vestbo J, Wouters EF, Vogelmeier CF, Jörres RA (2018) The revised GOLD 2017 COPD categorization in relation to comorbidities. Resp Med 134: 79–85 (Collaboration of the DZL sites ARCN, BREATH, CPC-M, TLRC, UGMLC)
5 Kahnert K, Jobst B, Biertz F, Biederer J, Watz H, Huber RM, Behr J, Grenier PA, Alter P, Vogelmeier CF, Kauczor HU, Jörres RA (2018) Relationship of spirometric, body plethysmographic, and diffusing capacity parameters to emphysema scores derived from CT scans. Chron Respir Dis 18: 1479972318775423 (Collaboration of the DZL sites ARCN, CPC-M, TLRC, UGMLC)
6 Kahnert K, Alter P, Welte T, Huber RM, Behr J, Biertz F, Watz H, Bals R, Vogelmeier CF, Jörres RA (2018) Uric acid, lung function, physical capacity and exacerbation frequency in patients with COPD: a multi-dimensional approach. Respir Res 19(1): 110. (Collaboration of the DZL sites ARCN, BREATH, CPC-M, UGMLC)
7 Graf J, Jörres RA, Lucke T, Nowak D, Vogelmeier CF, Ficker JH, Medikamentöse Therapie der COPD. Deutsches Ärzteblatt 115(37): 599-605 (Collaboration of the DZL sites CPC-M and UGMLC)
8 Alter P, Rabe KF, Schulz H, Vogelmeier CF, Jörres RA (2018) Influence of body mass on predicted values of static hyperinflation in COPD. Int J Chron Obstruct Pulmon Dis 13: 2551-2555 (Collaboration of the DZL sites ARCN, CPC-M, UGMLC)