Breathing-swallowing discoordination is associated with frequent exacerbations of COPD

Abstract

Introduction: Impaired coordination between breathing and swallowing (breathing-swallowing discoordination) may be a significant risk factor for the exacerbation of chronic obstructive pulmonary disease (COPD). We examined breathing-swallowing discoordination in patients with COPD using a non-invasive and quantitative technique and determined its association with COPD exacerbation.

Methods: We recruited 65 stable outpatients with COPD who were enrolled in our prospective observational cohort study and did not manifest an apparent swallowing disorder. COPD exacerbation was monitored for 1 year before and 1 year after recruitment. Swallowing during inspiration (the I-SW pattern) and swallowing immediately followed by inspiration (the SW-I pattern) were identified.

Results: The mean frequency of the I-SW and/or SW-I patterns (I-SW/SW-I rate) was 21.5%±25.5%. During the 2-year observation period, 48 exacerbation incidents (25 patients) were identified. The I-SW/SW-I rate was significantly associated with the frequency of exacerbation. During the year following recruitment, patients with a higher I-SW/SW-I frequency using thicker test foods exhibited a significantly higher probability of future exacerbations (p=0.002, log-rank test).

Conclusions: Breathing-swallowing discoordination is strongly associated with frequent exacerbations of COPD. Strategies that identify and improve breathing-swallowing coordination may be a new therapeutic treatment for patients with COPD.

Keywords: COPD Exacerbations; Lung Physiology; Respiratory Measurement.

Figure 1

A schematic diagram of the swallowing monitor.

Figure 2

Coordination between breathing and swallowing. Swallowing occurs during expiration, and respiration resumes with expiration (A: E–SW–E pattern). Swallowing occurs during inspiration (B: I-SW pattern), and respiration resumes with inspiration (C: SW-I pattern). The I-SW and SW-I patterns are unusual patterns, but may even occur in healthy subjects. E–SW–E, expiration–swallow–expiration; I-SW, swallowing during inspiration; SW-I, swallowing immediately followed by inspiration.

Figure 3

Kaplan-Meier curves of the probability of chronic obstructive pulmonary disease exacerbation during the year after recruitment: (A) stratified by the average I-SW/SW-I frequency with all four test foods; (B) stratified by the occurrence of I-SW/SW-I with level 0 test foods. I-SW, swallowing during inspiration; SW-I, swallowing immediately followed by inspiration.