Gender differences in emphysema severity identified
MedWire News: Canadian researchers have found gender differences in emphysema severity among smokers with, or at risk for, chronic obstructive pulmonary disease (COPD).
Writing in the journal Chest, Pat Camp (University of British Columbia, Vancouver, Canada) and team explain: “The authors of previous reports have suggested that women are more susceptible to cigarette smoke and to an airway-predominant COPD phenotype rather than an emphysema-predominant COPD phenotype.”
To investigate further, the researchers studied 688 men and women, aged 45–65 years, with or at risk for COPD who had a smoking history of at least 5 pack-years.
All the participants underwent lung function tests and completed a respiratory health questionnaire.
The presence and severity of emphysema was assessed using high-resolution computed tomography, with a “density mask” cut-off of -950 Hounsfield units used to calculate the low-attenuation area percentage (LAA%)
Airway wall thickness was assessed by calculating the square root of the airway wall area (SQRTWA), and the percentage of the total airway area taken by the airway wall (WA%) relative to the internal perimeter.
The researchers found that although women had smoked less than men, at an average of 37.8 versus 47.8 pack years, mean FEV1 was similar between the two genders, at 65.5% and 62.% of predicted, respectively.
Men had a higher mean LAA% than women, at 24% versus 20%, and larger emphysematous spaces. The SQRTWA and WA% were also larger in men than women, after adjusting for age, pack-years of smoking, current smoking status, height, weight, and FEV1 percent predicted.
Camp and team conclude: “Male smokers have more emphysema than female smokers, but female smokers do not show increased wall thickness compared with men.”
They add: “Our study should prompt further investigations on the complex nature of sex determinants and gender influences on the development of emphysema and airway wall remodeling in COPD.”
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By Mark Cowen