Influence factors of cough reflex sensitivity in patients with chronic cough

Abstract

Objective To investigate the influence factors of cough reflex sensitivity in patients with chronic cough. Methods Patients with chronic cough were recruited by using a diagnostic program. Cough reflex sensitivity was examined through eapsaicin cough challenge and the LgC5 (C5, the concentration of capsaicin causing five or more coughs ) was used as the index of cough threshold. Score of the severity of cough, age,gender, course of disease, pulmonary ventilation function (FEV1/pred%, MMEF/pred% )and cell differential of induced sputum (the percent of neutrophils, macrophages, lymphocytes, eosinophils)were also recorded for analysis. Results One hundred and fifty patients with different etiology of chronic cough involved in the study. Cough threshold of the patients was correlated with cough score at daytime (r=0.175, P 0.05 ). Regression analysis showed that only gender and disease course were significantly corrclated with LgC5 ( all P<0.01 ). Conclusions Cough reflex sensitivity and cough score reflex the different aspect of the cough severity. The cough reflex sensitivity in patients with chronic cough may be affected by gender and course. Key words: Chronic cough; Cough reflex sensitivity; Cough score