Asthma is a common chronic airways disease, with both medical and financial burdens imposed on society and individuals. Current evidence appears to show that there is a sex-based difference in the prevalence and severity of asthma. The reasons for this are starting to become clear based on recent research into the presence of receptor sites in the airways for the male hormone, testosterone.

Consider that asthma is more common in boys than girls, but the prevalence and severity is greater in adult women before menopause than in men. These findings correspond to changes in sex hormones, and suggest that sex hormones play a role in the development of asthma and the way it may progress with time. The airway effects of estrogen and progesterone on the physiology of asthma has been studied extensively. However, the effect of male hormones on asthma has not been well studied.

A recent study has shown that higher levels of testosterone are associated with better lung function in children. Testosterone levels were also found to be lower in men with severe disease than in those with less severe asthma. Boys and girls who were followed over many years were found to have less asthma symptoms when male hormone levels spiked in adolescence. This may explain why patients were thought to “outgrow” their asthma, which is clearly untrue. Other findings associated with increased male hormone levels include effects on some of the inflammatory factors noted in expired air of asthma patients.