Factors related to capsaicin cough sensitivity in healthy subject

咳嗽反射是抵抗吸入或吸入病原微生物的防御机制。我们假设咳嗽反射受损可能与复发性肺炎的发生有关，而咳嗽敏感性增加可能与过度咳嗽和慢性咳嗽有关，这是一种有害症状。咳嗽敏感性的研究是一个重要的问题，为了评估咳嗽敏感性的相关因素，我们招募了无呼吸道症状、无吸烟史、呼吸道疾病（包括近期上呼吸道感染和胃食管反流）、未服用ACE抑制剂的健康受试者。到目前为止，研究了30名受试者的ACE基因多态性，血清ACE活性，诱导痰中P物质的浓度，以及受试者的背景。这些发现和辣椒素咳嗽敏感性之间的相关性进行了研究。ACE基因多态性分析显示10例受试者在内含子16处存在插入/插入多态性，12例存在插入/缺失多态性，8例存在缺失/缺失多态性。在这30名受试者中，ACE基因多态性、血清ACE活性、诱导痰中P物质浓度、受试者背景与辣椒素咳嗽敏感性之间无显著相关性。我们正在招募更多的受试者，并进行进一步分析。另一组患有复发性肺炎但无基础疾病的受试者进行了咳嗽敏感性检查，并与年龄和性别匹配的对照组进行了比较。与对照组相比，那些患有复发性肺炎的受试者对辣椒素咳嗽反射不敏感。我们的结论是咳嗽反射受损可能与复发性肺炎的发展有关。

Cough reflex is a defence mechanism against aspiration or inhalation of pathogenic microorganisms. We hypothesized that impaired cough reflex may be related to the development of recurrent pneumonia, while increased cough sensitivity may be related to excessive cough and chronic cough, which is a noxious symptom. Investigation of cough sensitivity is an important issue.To assess the factors related to cough sensitivity, we have recruited healthy subjects who have no respiratory symptoms, no history of smoking, respiratory diseases including recent upper respiratory infection and gastroesophageal reflux, and who are not taking ACE inhibitors. Thus far, 30 subjects were studied regarding ACE gene polymorphism, serum ACE activity, concentration of substance P in induced sputum, and subjects' backgrounds. Correlations between these findings and capsaicin cough sensitivity were examined. Analysis of ACE gene polymorphism revealed that insertion/insertion polymorphism at intron 16 was found in 10 subjects, insertion/deletion polymorphism in 12 subjects, and deletion/deletion polymorphism in 8 subjects. In these 30 subjects, there were no significant correlations between the ACE gene polymorphism, serum ACE activity, concentration of substance P in induced sputum, subjects' backgrounds and capsaicin cough sensitivity. We are now recruiting more subjects and are further analyzing.Another subjects group with recurrent pneumonia but no underlying condition was examined about cough sensitivity and was compared to age and sex matched controls. Those subjects with recurrent pneumonia were insensitive to capsaicin cough reflex compared to controls. We have concluded that impaired cough reflex may be related to the development of recurrent pneumonia.