Is there evidence from biomarkers of systemic involvement in COPD exacerbations? No

Chronic obstructive pulmonary disease (COPD) is a disease associated with significant morbidity and mortality. The current GOLD guidelines recognize that the impact of COPD on an individual patient depends not just on the degree of airflow limitation, but also on the severity of symptoms (especially breathlessness and decreased exercise capacity), systemic effects, and any comorbidities the patient may have. Furthermore, COPD should be managed as a systemic disorder, with careful attention paid to comorbidities and their effect on the patient's quality of life. The main concomitant conditions associated with COPD are skeletal muscle weakness, osteoporosis, heart failure, cardiac arrhythmias, ischemic heart disease, stroke, depression, cancer etc. Recently, several investigators proposed that potentially a common mechanism by which major risk factors such as smoking, hyperlipidemia, obesity lead to chronic disease is systemic inflammation. Systemic inflammation may explain the development of chronic diseases such as COPD and its association with systemic and complex abnormalities affecting other organs. It has been suggested that persistent pulmonary inflammation promotes the release of pro-inflammatory chemokines and cytokines into the circulations. These mediators then stimulate various end-organs such as liver, adipose tissue, bone marrow that will release excessive amounts of acute phase proteins, inflammatory cells and secondary cytokines into the circulation and the result is a state of persistent low-grade systemic inflammation. The main controversia that exist today relates to the source in the respiratory system of inflammation. There is increased evidence that the functional impairment of airway-bronchial constriction that results in increased workload, hyperinflation and impaired respiratory muscle function is the main sources of inflammation. Recent reports characterize the upregulation of pro-inflammatory cytokines in the intercostals and other respiratory muscles. In theory, anti-inflammatory treatment should contribute to the reduction of exacerbations. Clinical studies that involve the use of long-acting bronchodilators, with or without inhaled corticosteroids; or surgical interventions such as volume reduction surgery have been associated with significant reduction in COPD exacerbation. Therefore, COPD is a disease associated with multiple co-morbid conditions, but the physiological consequences of airway obstruction, mainly hyperinflation may be the main precipitating factor of the systemic inflammatory response seen in these patients.