Smaller airway structures may increase risk for COPD in women

Smaller airway structures among women were associated with increased risk for chronic lung diseases including COPD, according to secondary analyses of the COPDGene cohort published in Radiology.

“The prevalence of COPD in women is fast approaching that seen in men, and airway disease may underlie some of the high COPD numbers in women that we are seeing,” Surya P. Bhatt, MD, MSPH, associate professor of medicine in the division of pulmonary, allergy and critical care medicine at the University of Alabama Lung Imaging Lab and Lung Health Center in Birmingham, said in a related press release. “When airways narrow due to cigarette smoking, the impact on symptoms and survival is greater in women than in men.”

The researchers used the COPDGene study to evaluate structural differences in airways and sex differences in the prevalence and outcomes of COPD. COPDGene included never-smokers (n = 420; mean age, 60 years; 57% women) and current and former smokers (n = 9,363; mean age, 60 years; 46% women) enrolled from 2008 to 2011. All patients were followed until November 2020 and underwent CT imaging to quantify airway disease using seven different metrics. Researchers tested associations between each metric and postbronchodilator FEV₁/FVC ratio, modified Medical Research Council dyspnea scale, St. George’s Respiratory Questionnaire score and 6-minute walk distance in ever smokers.

Among the never smokers, CT imaging showed men had thicker airway walls compared with women (least squares mean, 47.68 vs. 45.78; P = .02). However, women had lower airway lumen dimensions compared with men when the researchers accounted for height and total lung capacity (8.05 mm vs. 9.05 mm; P < .001).

Among ever smokers, men had greater segmental airway wall area percentage compared with women (52.19 vs. 48.89; P < .001) and women had a narrower segmental lumen diameter (7.8 mm vs. 8.69 mm; P < .001).

Researchers reported a unit change in each airway metric led to lower FEV₁/FVC ratio, more dyspnea, poorer respiratory quality of life, lower 6-minute walk distance and worse survival among women compared with men (P for all < .01).

“The differences in airway dimensions even after adjusting for height and lung size, and the greater impact of changes in airway size on clinical outcomes in women, was remarkable in that women appear to have a lower reserve against developing airway disease and COPD,” Bhatt said in the release.

Reference:

• Smaller airways increase COPD risk for women. Published Aug. 2, 2022. Accessed Aug. 2, 2022.