The purpose of this study is to determine the prevalence and severity of extrapulmonary disorders and to quantify the impact of extrapulmonary organ manifestations on morbidity and mortality of COPD patients.

Furthermore the investigators evaluate the relationship between systemic inflammation and organ involvement.

Chronic diseases and comorbidities have an increasing impact on individual life and health care use, as exemplified in chronic obstructive pulmonary disease (COPD). Currently, independent, comprehensive databases allowing for an integrated view are lacking. The study will for the first time establish a large, comprehensive longitudinal database covering a broad panel of comorbidities an markers of systemic alterations. These data will be of unique value in revealing specific phenotypes of COPD via patterns and risk profiles of comorbidities, enabling a more precise diagnosis and targeting of therapy, and an efficient allocation of resources.

Inclusion Criteria:

• aged 40 years and older
• diagnosis of COPD (GOLD-Criteria) or chronic bronchitis
• informed consent
• available for repeated study visits pver 18 months

Exclusion Criteria:

• having undergone big lung surgery (e.g. lung reduction, lung transplant)
• Moderate or severe exacerbation within the last 4 weeks
• having a lung tumor
• Unable to walk or to understand the intention of the project

Since the original recruitment strategy was not as successful as expected,the mode of recruitment was extended to other physicians, patients' groups and organisations and advertising to local media. The recruitment is supported by professional measures of communication organized by the coordinating centre Marburg.