Background Asthma is a common disease and a major public health concern. Respiratory symptoms are related to its prognosis, which in turn associates with lung function. Still this association on a long-term basis is not entirely understood. Aim To study the association of the type and number of respiratory symptoms with FEV1 and FEV1 decline in women and men with asthma. Method A population-based cohort of adults with asthma was examined at study entry between 1986 and 2001 and at follow-up between 2012 and 2014, and n=977 had valid measurements of FEV1 on both occasions. Data regarding respiratory symptoms at study entry (recurrent wheeze, dyspnoea, longstanding cough and productive cough) were analysed in relation to FEV1 and annual decline in FEV1, both unadjusted and adjusted for other potentially associated factors by linear regression. Results For both sexes recurrent wheeze and dyspnoea were associated with lower FEV1 at study entry and follow-up, while productive cough was associated with lower FEV1 only at follow-up. No associations were found between the type of symptoms and annual decline in FEV1. In adjusted analyses, the association between recurrent wheeze and lower FEV1 both at study entry and follow-up remained significant among women. Also, the association between a higher number of symptoms with lower FEV1 both at study entry and follow-up were present for both sexes and remained after adjustment. Conclusions Particularly recurrent wheeze and a higher number of respiratory symptoms may predict lower lung function also in the long run among women and men with asthma. Data are available upon reasonable request.

中文翻译：

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在呼吸道症状中，喘息与成人哮喘患者肺功能受损的关系最为密切：一项长期前瞻性队列研究

背景 哮喘是一种常见疾病，也是一个主要的公共卫生问题。呼吸道症状与其预后相关，而预后又与肺功能相关。然而，这种长期关联仍然没有被完全理解。目的 研究女性和男性哮喘患者的呼吸道症状类型和数量与 FEV1 和 FEV1 下降的关系。方法 在 1986 年至 2001 年研究开始时以及 2012 年至 2014 年随访期间对以人群为基础的成人哮喘患者队列进行了检查，n=977 人在这两种情况下均进行了有效的 FEV1 测量。研究开始时有关呼吸道症状的数据（反复喘息、呼吸困难、长期咳嗽和排痰性咳嗽）与 FEV1 和 FEV1 年度下降相关进行分析，均未经调整，并通过线性回归针对其他潜在相关因素进行调整。结果 对于男女，反复喘息和呼吸困难与研究开始和随访时较低的 FEV1 相关，而排痰性咳嗽仅与随访时较低的 FEV1 相关。未发现症状类型与 FEV1 年度下降之间存在关联。在调整后的分析中，女性患者在研究开始和随访时反复喘息与较低的 FEV1 之间的关联仍然显着。此外，在研究开始和随访时，较多症状与较低 FEV1 之间的关联在两性中均存在，并且在调整后仍然存在。结论 从长远来看，特别是反复发作的喘息和较多的呼吸道症状也可能预示着女性和男性哮喘患者的肺功能较低。数据可根据合理要求提供。