Are Undersized Airways the Cause of COPD in Nonsmokers?
ONE IN FOUR patients with chronic obstructive pulmonary disease (COPD) have never smoked and the reasons behind this have long evaded researchers. Interestingly, a team at Columbia University Irving Medical Center, New York City, New York, USA have found that patients with small airways relative to their lungs’ volume (known as dysanapsis) are at increased risk of COPD, regardless of smoking habits.
CT scans were analysed of >6,500 adults who were enrolled in three major lung studies in the USA and Canada. The results showed that participants with normal lung function experienced rapid decline in function after exposure over many years to irritants such as cigarette smoke and air pollution. However, it was shown that those with reduced lung function from an early age also increased the risk of COPD in their later years, despite lack of exposure to lung irritants.
Lead author Prof Benjamin Smith of Columbia University Vagelos College of Physicians and Surgeons commented that dysanapsis is believed to arise early in life and stated: “Our study shows that having an undersized airway tree compromises breathing and leaves you vulnerable to COPD later in life.”
Prof Smith and his team were motivated to carry out this research after a recent study reported that half of older adults with COPD had low lung capacity in their early life. COPD, emphysema, and chronic bronchitis are collectively known for being the third-leading cause of death in the USA.
“Combining classic theories from respiratory physiology with state-of-the-art imaging in large epidemiological samples, we tested whether dysanapsis might explain a significant proportion of COPD risk,” explained Prof Smith. The team are hopeful that their findings will lead to early life interventions to ensure lung development is healthy and resilient.