British researchers have uncovered a significant link between night shift work and an increased risk of developing asthma in women, particularly those who are postmenopausal and not using hormone replacement therapy (HRT). The research, “Increased Risk of Asthma in Female Night Shift Workers,” was based on data from more than 280,000 participants in the U.K. Biobank. The study was published in ERJ Open Research and highlights a growing public health concern as more women enter shift-based professions.
According to the research, female permanent night shift workers had a 50% higher chance of developing moderate to severe asthma compared to their counterparts working regular daytime hours. By contrast, no similar increase in asthma risk was observed among male night shift workers.
The study noted the elevated asthma risk in women was most pronounced among postmenopausal women not using HRT. In this group, the odds of developing moderate to severe asthma were nearly double. However, this risk was not evident in postmenopausal women who were on HRT, suggesting a potential protective effect of hormone therapy.
“This is the first study to evaluate sex differences in the relationship between shift work and asthma. This type of research cannot explain why shift work and asthma are linked. However, it could be because shift work disrupts the body clock, including the levels of male and female sex hormones,” the study’s lead author, Robert Maidstone, a research fellow at the University of Manchester, said in a press release. “High testosterone has previously been shown to be protective against asthma, and so lower testosterone in women could play a role. Alternatively, men and women work different types of shift jobs, and this could be a factor."
Researchers called for further investigation into whether adjusting shift schedules or the use of HRT could help reduce asthma risk in female workers. They also urged public health officials and employers to reevaluate workplace policies to better support the respiratory health of female employees.
