Dear friends we are happy to present you new interesting review on new clinical entity: chronic respiratory symptoms in persons with normal spirometry!
The 2001 Global Initiative for Chronic Obstructive Lung Disease (GOLD) Report defined five stages of spirometric severity (post-bronchodilator FEV1/FVC≥0.7): 0, and 1 (mild) to 4 (very severe). GOLD Stage 0 was defined by chronic cough and sputum production or chronic mucus hypersecretion (CMH) alone with preserved FEV1/FVC. Subsequently, GOLD 0 was discarded as further evidence of COPD development in subjects with GOLD 0 was not more likely to develop.
When expanding symptomatic burden in GOLD 0 to include other chronic respiratory symptoms, such as dyspnea, wheeze, poor quality of life, limited physical activity, and ‘COPD exacerbations-like’ events needing health resources, symptomatic smokers with normal FEV1 resulted in larger risk of death. We review the evidence supporting a relationship between an increased symptom burden, long-term FEV1 decline and development of COPD. We also address the evidence for the presence of respiratory symptoms with normal FEV1 in smokers as a potential clinical entity. This subset of symptomatic patients encompasses a compelling category of smokers with normal spirometry but increased risk for poor outcomes. What exactly these symptomatic patients with intact FEV1 represent remains unclear. Whether they exemplify smoking-induced just a broadening of respiratory abnormalities or a distinct clinical entity that precedes the development of COPD or both remains unknown. Other aims, such as providing information on pathogenesis and future areas of research, are just as vital. What ultimately prevails however is the importance of the public health message to the frightening presence of chronic respiratory symptoms in the whole population.