Changes in Inflammatory Markers During Pulmonary Rehabilitation Based on Exacerbation States in COPD

Changes in Inflammatory Markers During Pulmonary Rehabilitation Based on Exacerbation States in COPD

This study will examine the inflammatory response to exercise encompassed as part of a standard pulmonary rehabilitation programme in patients with chronic obstructive pulmonary disease (COPD). Patients will be split into two groups, frequent exacerbators or infrequent exacerbators, dependent upon exacerbation history to compare responses to pulmonary rehabilitation amongst phenotypes.

Pulmonary rehabilitation has been proven to benefit COPD patients in terms of quality of life and functional capabilities. The effects of pulmonary rehabilitation (exercise) on immune function are unclear despite clear benefits of exercise on immune function in healthy individuals being identified. Moderate-intensity and frequency of exercise has been shown to decrease the risk of upper respiratory tract infections in healthy individuals in comparison to sedentary individuals. Respiratory infections, also known as exacerbations, in COPD are the main cause of hospitalisation and mortality. Therefore, if exercise can modulate immune function in COPD, it can be encouraged further in COPD to reduce hospitalisation risk. However, it is important to compare the effects of exercise amongst different phenotypes as frequent exacerbators are known to have elevated inflammatory markers, and may consequently respond to exercise differently to infrequent exacerbators, paving a rationale for a different approach to this subset of patients.

Inclusion Criteria:

• 58 frequent exacerbators and 58 infrequent exacerbators (116 in total) who have been diagnosed with any severity of COPD (according to BTS criteria, i.e. >10 pack year smoking history and post bronchodilator spirometry FEV1/FVC ratio <0.70 and FEV<80%).

Exclusion Criteria:

• Inability or unwillingness to sign informed consent
• Any unstable ongoing cardiovascular events which may be exacerbated by exercise
• Inability to complete walk tests due to physical or mental impairment
• Other active inflammatory conditions e.g. rheumatoid arthritis, cancer.
• Known asthma, allergic rhinitis or other respiratory disease (bronchiectasis, pulmonary fibrosis)

Healthy control group - Patients who have not been diagnosed with COPD or any other respiratory condition and are characteristically (age (between 45-85 years old) & smoking status) matched to recruited COPD patients.