Asthma or COPD was diagnosed according to the criteria of the American Thoracic Society, GINA, GOLD guideline
Acute exacerbation was defined by the criteria of the American Thoracic Society, GINA, GOLD guideline
For stable disease, none of the subjects had received inhaled or oral corticosteroids or any other anti-inflammatory drugs, had an exacerbation history in the previous 6 months
