Sex-related Differences in Airway Dimensions: A Study Based on Quantitative Computed Tomography among Chinese Population

Sex-dependent radiation injury may be related to the differences in physiological characteristics between the sexes. This study aimed to better understand variations in airway dimensions among male and female Chinese non-smokers. This study included 970 adults and 45 children who underwent chest CT. All participants were non-smokers, without current or former chronic pulmonary disease, and all underwent CT examination. The CT images were quantitatively assessed, providing airway dimensions. The differences in inner diameter, wall thickness, wall area (WA), and WA% for each airway were compared between male and female patients. Sex is an important influencing factor in airway morphological parameters. These parameters are different between men and women: men have a larger airway diameter (P < 0.05) and smaller wall area (WA%, P < 0.05) compared with women. Younger women (<35 years) have a greater diameter and smaller WA% compared with older women (P < 0.05). Sex-related differences in airway morphology were not observed in pediatric participants. Significant differences were found in quantitative CT measures of WA% and an internal diameter among non-smokers of varying sex. The differences found in this study might explain, in part, sex-dependency of radiation injury and a possible radiological protection scheme.