Night Shifts Linked to Increased Asthma Risk in Postmenopausal Women: Study

A recent study using data from over 280,000 participants in the UK Biobank revealed a strong link between night shift work and asthma risk in women, particularly in postmenopausal women not using hormone replacement therapy (HRT). The findings published in the ERJ Open Research, highlighted the need to examine how occupational patterns intersect with biological factors to influence respiratory health.

Asthma, already more prevalent in females than males, has also been previously associated with night shift work. With more women joining the shift work labor force, scientists sought to determine whether the asthma risk tied to shift work differs between sexes.

This study employed logistic regression models to assess asthma prevalence across various work schedules, adjusting for factors like age, smoking status, body mass index, and socioeconomic status. The results revealed that women working permanent night shifts had a 50% higher risk of moderate to severe asthma when compared to their counterparts working regular daytime hours. In contrast, no significant association was observed in men.

Also, female night shift workers showed an odds ratio (OR) of 1.50 (95% confidence interval [CI] 1.18–1.91) for moderate to severe asthma when compared to female day workers. Men working night shifts had an OR of 0.95 (CI 0.72–1.26), which suggested no increase in the risk. A statistically significant sex interaction (p=0.01) further highlighted that the relationship between shift work and asthma is indeed stronger in women.

The findings were consistent across broader asthma indicators, including self-reported asthma and symptoms such as wheezing or whistling in the chest. This study explored whether the increased risk in women was related to hormonal changes. Among postmenopausal women not using HRT, the asthma risk was even higher, with an adjusted OR of 1.89 (CI 1.24–2.87) for moderate to severe asthma in permanent night workers versus day workers. However, this elevated risk disappeared among postmenopausal women who were using HRT, suggesting a potential protective effect.

The study also considered chronotype (morning or evening preference), but the observed sex-specific risks remained most clearly aligned with menopause and HRT status rather than sleep timing preference alone. These findings suggest that circadian rhythm disruption, hormonal imbalances, or both may underlie the heightened vulnerability observed in women. Overall, these findings stress the need for proactive health monitoring and tailored workplace policies aimed at minimizing chronic disease risk linked to modern work patterns.

Source:

Maidstone, R. J., Ray, D. W., Liu, J., Bowden, J., Rutter, M. K., & Durrington, H. J. (2025). Increased risk of asthma in female night shift workers. ERJ Open Research, 00137–02025. https://doi.org/10.1183/23120541.00137-2025