Evaluation of swallowing function by two screening tests in primary COPD.

Swallowing is an important function to separate the airway and the oesophagus. Dysfunction of this mechanism may lead to aspiration of pathogenic oropharyngeal contents. The disorder of swallowing function can be evaluated by the simple two-step swallowing provocation test (STS-SPT) and repetitive saliva swallowing test (RSST) [1, 2]. Both screening tests are safe, rapid and of low cost. Recently, it has been reported that the swallowing dysfunction may be a risk factor for an exacerbation of chronic obstructive pulmonary disease (COPD) [3]. Therefore, detection of the swallowing dysfunction at an earlier stage of COPD may be very important in management of COPD patients and to prevent advancing stages of the disease. Swallowing dysfunction in advancing stages of COPD has been reported [3, 4]. However, it is unclear whether swallowing functions are disordered in primary COPD. The present study was conducted to elucidate swallowing function before exacerbation of COPD, especially at a mild stage, as defined by the Global Initiative for Chronic Obstructive Lung Disease (GOLD) classification [5], using the STS-SPT and the RSST. The present correspondence is presented as a preliminary to a prospective study investigating the probability of exacerbation.