Capsaicin cough reflex sensitivity may help prevent severe acute exacerbations among COPD patients

Patients suffering from Chronic Obstructive Pulmonary Disease (COPD) often face hospitalization due to severe acute exacerbation (AE) or community-acquired pneumonia (CAP). Now, a new study by BMJ open Respiratory Research suggests that the sensitivity of the cough reflex could be a crucial factor associated with these hospitalizations.

Researchers conducted a prospective study that included 68 COPD patients between June 2018 and January 2020. They assessed patient characteristics, lung and cardiac functions, and various biomarkers, including capsaicin cough reflex sensitivity and blood eosinophil count, upon enrollment. All participants were closely monitored for 12 months for any instances of AE or CAP requiring hospitalization.

The results revealed that eight patients experienced severe AE (3) or CAP (5) and needed hospitalization during the follow-up period. Patients in the hospitalization group demonstrated higher modified Medical Research Council scores and elevated blood eosinophil counts (≥300 µL) compared to those who didn't require hospitalization.

Most notably, the study showed that capsaicin cough reflex sensitivity seemed to decrease in patients who were later hospitalized due to AE or CAP. Through a multivariate analysis, the researchers identified decreased capsaicin cough reflex sensitivity and high eosinophil counts (≥300 µL) as predictive risk factors for future hospitalization due to AE-COPD or CAP.

This study has critical implications for the management of COPD. Beyond the already established relationship between elevated eosinophil counts and COPD exacerbations, the sensitivity of the cough reflex could potentially help identify those at higher risk of hospitalization.

This study highlights the significance of capsaicin cough reflex sensitivity in COPD patients. It not only identifies a previously overlooked risk factor for severe AE or CAP but also provides potential insights for preventive measures. By better understanding these associations, medical professionals may be better equipped to predict and manage hospitalizations in COPD patients, ultimately improving their overall quality of life.

Reference:

Kanemitsu, Y., Kurokawa, R., Akamatsu, T., Fukumitsu, K., Fukuda, S., Ito, Y., Takeda, N., Nishiyama, H., Ito, K., Tajiri, T., Mori, Y., Uemura, T., Ohkubo, H., & Niimi, A. (2023). Decreased capsaicin cough reflex sensitivity predicts hospitalisation due to COPD. In BMJ Open Respiratory Research (Vol. 10, Issue 1, p. e001283). BMJ. https://doi.org/10.1136/bmjresp-2022-001283