The role of circulating sex hormones in mild-to-moderate asthma: cross-sectional analysis within the Rotterdam Study

Two thirds of patients with asthma are female, suggesting an immune modulatory effect of sex hormones in asthma. In a limited number of studies, testosterone has been linked to a protective effect against asthma. The Rotterdam Study (RS) is a prospective population-based cohort study in Rotterdam, the Netherlands. Since 1990, 18926 participants have been enrolled in 4 longitudinal RS subcohorts. Asthma cases have been validated based on medical records. Morning fasting serum levels of circulating sex steroids (testosterone and its precursors androstenedione, dehydroepiandrosterone(−sulphate) (DHEA(S)); estradiol) and cortisol have been measured in a subset of 4533 participants. The analysis included 485 participants with (mild-to-moderate) asthma (not dependent on oral corticosteroids) and 4048 non-asthmatic controls with a respective mean age of 62.1 and 64.6 years. <fig><object-id>erj;64/suppl_68/PA3080/F1</object-id><object-id>F1</object-id><object-id>F1</object-id><graphic></graphic></fig> In women with asthma, testosterone was significantly lower compared to non-asthmatic controls (Figure 1). In asthmatic men, there was a significant decrease in levels of DHEA, DHEAS and androstenedione; and for testosterone after adjustment for age. In a large population based study we demonstrate lower levels of testosterone in females with mild asthma and lower levels of testosterone precursors in males with asthma. Our findings suggest a protective effect of testosterone in asthma, encouraging further mechanistic studies.