Study: Night shifts increase asthma risk for women

Editor's Note

Women who work night shifts are around 50% more likely to have moderate or severe asthma compared to women who work only during the day, according to findings published in ERJ Open Research.

As detailed in a June 15 announcement from the European Respiratory Society, the study analyzed data from 274,541 employed individuals in the UK Biobank. Among them, 5.3% had asthma, and 1.9% had moderate or severe asthma, defined as the use of a preventer inhaler plus at least one other treatment such as an oral steroid. Participants were grouped by whether they worked only daytime shifts, only night shifts, or a combination of both. 

Women working only night shifts had higher odds of moderate or severe asthma compared to daytime-only workers—an association not observed in men, the organization notes. The analysis also found that postmenopausal women not taking hormone replacement therapy had almost double the risk of moderate or severe asthma if they worked night shifts compared to day shifts. The organization states that these results suggest HRT might be protective, but further research is needed to test this in prospective and randomized studies.

Reportedly the first study to evaluate sex differences in the relationship between shift work and asthma, the analysis did not determine the reasons for the link. Possible explanations include circadian rhythm disruption and the influence of sex hormone levels. Researchers plan to investigate these mechanisms further using additional data from the UK Biobank and the Our Future Health stud.