Abstract

A normal spirometry is often used to preclude airway disease in individuals with unspecific respiratory symptoms. We tested the hypothesis that chronic respiratory symptoms are associated with respiratory hospitalisations and death in individuals with normal spirometry without known airway disease. We included 108,246 randomly chosen individuals aged 20-100 from a Danish population-based cohort study. Normal spirometry was defined as a pre-bronchodilator forced expiratory volume in 1s(FEV1)/forced vital capacity(FVC)=0.70. Chronic respiratory symptoms included dyspnoea, chronic mucus hypersecretion, wheezing, and cough. Individuals with known airway disease, i.e. chronic obstructive pulmonary disease and/or asthma, were excluded (n=10,291). We assessed risk of hospitalisations due to exacerbations of airway disease and pneumonia, and respiratory and all-cause mortality from 2003 through 2018. 52,999 had normal spirometry without chronic respiratory symptoms and 30,890 had normal spirometry with chronic respiratory symptoms. During follow-up, we observed 1037 hospitalisations with exacerbation of airway disease, 5743 hospitalisations with pneumonia, and 8750 deaths, of which 463 were due to respiratory disease. Compared to individuals with normal spirometry without chronic respiratory symptoms, multivariable adjusted hazard ratios for individuals with normal spirometry with chronic respiratory symptoms were 1.62(95% confidence interval:1.20-2.18) for exacerbation hospitalisations, 1.26(1.17-1.37) for pneumonia hospitalisations, 1.59(1.22-2.06) for respiratory mortality, and 1.19(1.13-1.25) for all-cause mortality. There was a positive dose-response relationship between number of symptoms and risk of outcomes. Results were similar after 2 years follow-up, for never-smokers alone, and for each symptom separately. Chronic respiratory symptoms are associated with respiratory hospitalisations and death in individuals with normal spirometry without known airway disease.

Full Text

Comments

Adults with respiratory symptoms and spirometry within normal limits have increased respiratory risks over the next 8 years. This is a follow-up from a Danish population sample showing that adults with respiratory symptoms and normal spirometry are more likely to die, have hospital admissions for pneumonia and airflow obstruction, than adults with similar spirometry and no respiratory symptoms. Their spirometry was lower than those without symptoms but the increased risks remained after adjustment for FEV1. Those with airflow obstruction and no symptoms had the same outcomes as those with normal spirometry and symptoms. Those with both symptoms and airflow obstruction did worst.

7/15/2019

thank you

8/26/2019

zFuLAHMcGgtDiZXf

10/16/2019

ASwOskHEp

10/16/2019