A Study on the Association between Cough Sensitivity and Acute Exacerbations in Patients with Chronic Obstructive Pulmonary Disease.

Objective: To investigate the relationship between cough sensitivity and acute exacerbation in stable chronic obstructive pulmonary disease (COPD) patients.

Methods: Stable COPD patients who visited our department from July 2022 to June 2023 were included. They were subjected to cough sensitivity test, spirometry, induced sputum cytology examination, questionnaire assessment such as cough symptom score, etc. They were followed up for 12 months, and were divided into the acute exacerbation (AE) group and the stable group according to whether acute exacerbation occurred during the follow-up period. We compared the differences in cough sensitivity, pulmonary function, and questionnaires between the two groups, analyzed the relationship between cough sensitivity and acute exacerbation, and screened the risk factors for AECOPD.

Results: A total of 145 patients with stable COPD were included. AE group (n = 94) had lower FEV₁/FVC (50.08 ± 11.11 versus 54.28 ± 11.58, p = 0.03) and cough sensitivity lgC₅ [-0.01(0.90) versus 0.59(0.90), p < 0.01] than those in the stable group (n = 51) patients, the daytime cough symptom score [2(2) versus 1(2), p = 0.02] and VAS score [50(40) versus 30(50), p < 0.01] were higher than stable group. Multivariate logistic regression analysis showed lgC₅ (OR = 0.34, 95% CI = 0.16-0.71, p < 0.01) was an independent risk factor for AECOPD. When lgC₅ was used to predict acute exacerbation in stable COPD patients, the AUC was 0.69, the sensitivity was 59.57%, and the specificity was 72.55%.

Conclusion: Although causality is not necessarily demonstrated, baseline cough sensitivity lgC₅ in stable COPD patients is an independent risk factor for AECOPD, and it has some predictive value for future acute exacerbations.