Abnormal swallowing reflex and COPD exacerbations.
BACKGROUND
It is unclear whether an abnormal swallowing reflex affects COPD exacerbations. This study investigated the prevalence of abnormal swallowing reflexes and its relationship with COPD exacerbation prospectively. We also clarified its association with gastroesophageal reflux disease (GERD) and airway bacterial colonization.


METHODS
Swallowing reflex and serum C-reactive protein (CRP) levels were examined in subjects with stable COPD and in control subjects. Concurrently, GERD symptoms were assessed using a self-reported questionnaire, and sputum bacterial cultures were investigated in the same subjects. Exacerbations were counted prospectively during the following 12 months.


RESULTS
The study group comprised 67 subjects with COPD and 19 controls. The prevalence of abnormal swallowing reflex was significantly higher in subjects with COPD (22/67) than controls (1/19; P = .02). Among subjects with COPD, the serum CRP level, GERD symptoms, isolation of sputum bacteria, and the frequency of exacerbations were significantly increased in those with abnormal swallowing reflexes compared with controls (2.72 vs 1.04 mg/L, P = .04, for serum CRP level; 6.75 vs 4.10 points, P = .04, for GERD symptoms; 5/11 vs 3/22, P = .04, for the isolation of sputum bacteria; and 2.82 vs 1.56/y, P = .007, for the annual frequency of exacerbations). Multivariable analysis confirmed that abnormal swallowing reflex was significantly associated with frequent exacerbations (>or= 3/y; P = 0.01).


CONCLUSIONS
Abnormal swallowing reflexes frequently occurred in subjects with COPD and predisposed them to exacerbations. Abnormal swallowing reflexes in COPD might be affected by the comorbidity of GERD, and cause bacterial colonization.
Department of Respiratory Medicine, Kyoto University, Sakyo-ku, Kyoto, Japan.
Kunihiko
K
Terada
Shigeo
S
Muro
Tadashi
T
Ohara
Megumi
M
Kudo
Emiko
E
Ogawa
Yuma
Y
Hoshino
Toyohiro
T
Hirai
Akio
A
Niimi
Kazuo
K
Chin
Michiaki
M
Mishima
D000368:Aged; D003679:Deglutition / Q000502:physiology*; D003680:Deglutition Disorders / Q000209:etiology / Q000503:physiopathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D011379:Prognosis; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications / Q000503:physiopathology*; D012008:Recurrence; D011795:Surveys and Questionnaires