There is increasing appreciation of gender differences in COPD but scant data whether risk factors for low lung function differ in men and women. We analysed data from 3 years follow-up in 178 women and 464 men with COPD, participants in the Euroscop Study who were smokers unexposed to inhaled corticosteroids.
Methods
Explanatory variables of gender, age, starting age and pack-years smoking, respiratory symptoms, FEV1%FVC and FEV1%IVC (clinically important measures of airway obstruction), body mass index (BMI), and change in smoking were included in multiple linear regression models with baseline and change in post-bronchodilator FEV1 as dependent variables.
Results
Reduced baseline FEV1 was associated with respiratory symptoms in men only. Annual decline in FEV1 was not associated with respiratory symptoms in either men or women, and was 55 ml less in obese men (BMI⩾30 kg/m2) than men having normal BMI, an effect not seen in women. It was 32 ml faster in women with FEV1%FVC<median than women with less airway obstruction, a larger difference than in men (8 ml per year). It was 17.7 ml/year faster when increasing the daily number of cigarettes by 10 in men only, but not significantly greater than in women.
Conclusion
Respiratory symptoms were associated with reduced baseline FEV1 in men with COPD. In men, obesity was associated with reduced decline and increasing the number of cigarettes smoked with increased decline in lung function. In women more severe airway obstruction was associated with accelerated decline.
The original study from which this data is taken, was sponsored by Astra Zeneca, Sweden. The company has not funded these analyses, but have approved this manuscript.