Structural differences in the pulmonary airways between men and women may underlie differences in the prevalence of chronic obstructive pulmonary disease between the sexes. This is what appears from a large American multicenter study published in the journal Radiology, which measured the repercussions of tobacco in this context by CT scanning.
Chronic obstructive pulmonary disease (COPD) affects more men, who have a higher diagnosis and mortality rate, but smoking and increasing urbanization increase its incidence in women.
Physiological differences between the respiratory systems of women and men
« The prevalence of COPD in women is rapidly approaching that seen in men, and diseases of the respiratory tract may underlie some of the high numbers of COPD in women that we see.notes the lead author ofa study published in the Revue RadiologyDr. Surya P. Bhatt, practices in the Division of Pulmonary, Allergy and Critical Care Medicine at the University of Alabama at Birmingham. When the airways narrow due to smoking, the impact on symptoms and survival is greater in women than in men. »
The hypothesis that women have smaller airways is based on comparisons of the trachea and main bronchi, but few studies have compared distal airways or lung size in normal individuals.
A large-scale study to determine the effects of tobacco using CT scans
For this study, researchers analyzed data from nearly 10,000 participants enrolled in Genetic Epidemiology of COPD (COPDGenes), a prospective, multicenter observational cohort study of current and former smokers, as well as nonsmokers, between the ages of 45 and 80 years. in 21 health care facilities across the United States. They looked at data from current and former smokers enrolled in COPDGene from January 2008 to June 2011 and followed them through November 2020.
COPD was analyzed by lung CT scan with measurements of airway wall thickness, percent wall area, Pi10 – square root of airway wall thickness with an inner circumference of 10 mm – for airway wall, diameter, airway lumen, airway volume, total number of airways as well as airway fractal dimension.
Smoking causes a higher incidence of COPD in women
Each airway measurement was calculated and adjusted for age, height, race, body mass index, number of pack-years of smoking, current smoking status, and total lung capacity. ” Airway and lung growth in early life is generally more proportional in females than in males adds Dr Bhatt.
In 420 non-smokers, computed tomography (CT) scans revealed that men had thicker airway walls than women, while, after accounting for height and total lung capacity, airway lumen dimensions were lower in women than in men.
Research gender-appropriate COPD therapies
In 9,363 current and former smokers, men had greater wall thickness, while women had a narrower segmental lumen diameter. A unit change in each of the airway measurements (upper wall or lower lumen measurement) resulted in poorer lung function, more dyspnoea, poor respiratory quality of life, six fewer walking minutes and lower survival in women compared to men.
« The differences in airway dimensions, even after adjustment for height and lung size, and the greater impact of changes in airway size on clinical outcomes in women, were remarkable in that women appeared to have a lower reserve against the development of airway disease and COPD. include dr. Bhatt, encouraging research to consider gender differences in the development of new therapies for diseases of the respiratory tract.
Bruno Benque with RSNA