The Global Initiative for Chronic Obstructive Lung Disease (GOLD) aims to increase awareness and research regarding chronic obstructive pulmonary disease (COPD), with the overarching goal of improving COPD prevention, diagnosis, and treatment. The GOLD annual report provides recommendations for COPD management; however, the scientific committee responsible for developing these recommendations notes that there are still many areas that require further clarity to inform recommendations.
To that end, the GOLD committee held a public forum to define these knowledge gaps and summarized the information gleaned from that discussion in a recent paper published in the Annals of the American Thoracic Society.1 Selected points and prevailing questions from the paper are highlighted below.
- Is airflow limitation essential to COPD diagnosis and treatment?
COPD diagnosis requires airflow limitation confirmed by spirometry, however, emerging research2,3 has demonstrated “respiratory symptoms in smokers without airflow limitation, severe enough to impact quality of life and associated with exacerbation-like events,” the authors wrote.1 “Thus, the question arises as to whether these subjects suffer from COPD, and if so, would it be possible to diagnose COPD without the presence of airflow limitation?” It has been suggested that these cases could be referred to as “pre-COPD” in an updated COPD taxonomy.
- Role of thoracic imaging
Observations from chest computed tomography (CT) imaging point to its potential value in identifying COPD subtypes associated with varying responses to treatment. In the National Emphysema Treatment Trial, for example, no overall benefit was found for lung volume reduction surgery vs medical therapy in severe emphysematous COPD.4 However, symptom reduction and improved survival were observed in patients with low exercise capacity and upper zone predominant emphysema on CT.
- Cigarette smoking vs biomass exposure
Some of the COPD risk factors discussed in the paper include abnormal lung development early in life, passive smoking, childhood asthma, and repeated infections. Exposure to biomass smoke vs tobacco smoking was also examined, and although both types of exposure are associated with a similar risk for mortality and COPD, each has been linked with different phenotypes. For instance, women “with COPD from tobacco exposure have more emphysema than those exposed to biomass fumes who have more air trapping and less respiratory symptoms,” according to the authors.1