Correlation of Physical Activity and Respiratory Health in COPD Patient

Chronic Obstructive Pulmonary Disease (COPD) is a heterogeneous and multisystemic disease with progressive increasing morbidity and mortality. Chronic obstructive pulmonary disease (COPD) is a deteriorating respiratory disease with some extrapulmonary effects that contribute to disease severity in patient. The etiology, in general, involves exposure to external noxious particles or gases. In the Western world this is particularly a result of (cigarette) smoking and in the non-Western world it is mainly a result of indoor cooking. COPD pathology is driven by chronic inflammation, which continues to be observed after stopping smoking, even after ⩾1 year. The combination of the exposure and inflammation leads to lung tissue damage, resulting in remodeling of the lung.Global Burden of Disease programme in 2010 identified chronic obstructive pulmonary disease (COPD) as the third leading cause of death worldwide up from 4th in 1990. This high mortality due to COPD is caused due to smoking and rapidly aging population. China alone contributed to about one-third (0.9million/year) of all deaths from COPD worldwide. Within China, the prevalence of COPD varies substantially by region and death rates attributed to COPD are twofold greater in South-West compared with North-East regions for reasons that are not fully understood.

Physical activity in terms of body movements, walking time and standing time has been shown to be reduced in patients with severe COPD. However, it is currently unknown at which clinical stage of the disease limitations of physical activity are first displayed. Furthermore, the relationships between physical activity and clinical characteristics reflecting the disease severity, such as the degree of airway obstruction, distance walked in 6 min, self-reported grade of dyspnea and clinical stages of COPD, need to be investigated as, to date, data are inconclusive or have never been evaluated. For example, some studies have found substantial correlations between airway obstruction and physical activity, while others found no or only loose relationships. Previous studies indicate that the 6-min walking distance (6MWD) might best reflect physical activity, while a recent study found airway obstruction to correlate with physical activity better than 6MWD.