Study Reveals Increased Asthma Risk for Women Working Night Shifts

A recent study highlights a concerning link between night shift work and asthma prevalence among women. The research, published in ERJ Open Research, indicates that women who engage in night shifts are significantly more likely to experience moderate to severe asthma compared to their daytime counterparts.

Conducted by a team including researchers from the University of Manchester, this study analyzed data from over 270,000 participants. The findings showed that while 5.3% of the overall population reported having asthma, 1.9% suffered from moderate or severe asthma, characterized by the need for preventive inhalers and additional treatments such as oral steroids. Participants were categorized based on their work schedules: exclusively daytime, exclusively night shifts, or a combination of both.

The results revealed that female night shift workers have approximately a 50% higher risk of developing moderate or severe asthma compared to those who work during the day. In contrast, the asthma risk for men did not show a similar correlation with their work schedule.

Dr. Robert Maidstone, who led the research, noted that while asthma is known to affect women more severely overall, this study is the first to specifically examine gender differences in the context of shift work. He mentioned that previous studies indicated a heightened risk of asthma among night shift workers, prompting the current investigation into sex-specific outcomes.

Data from the UK Biobank formed the backbone of this analysis, allowing researchers to delve deeper into the factors influencing asthma prevalence. The research team discovered that postmenopausal women working night shifts had nearly double the risk of moderate or severe asthma compared to those working daytime hours, particularly among those not undergoing hormone replacement therapy (HRT).

While the study establishes a link, it does not elucidate the underlying reasons for this association. Dr. Maidstone speculated that disruptions to the circadian rhythm caused by shift work might influence hormone levels, potentially impacting asthma risk. For instance, low testosterone levels in women may be a contributing factor, as higher testosterone levels are believed to offer some protective effects against asthma.

There is a pressing need for further research to explore potential protective measures for women working night shifts. The study suggests that HRT could be beneficial in reducing asthma risk for this demographic, although more extensive studies are required to confirm this hypothesis.

Professor Florence Schleich of the European Respiratory Society, who did not participate in the study, emphasized the significance of these findings. She acknowledged the complexities surrounding asthma, particularly its disproportionate impact on women, and called for additional research to clarify the relationship between shift work and asthma. Understanding these dynamics is crucial for developing strategies to mitigate risks for female shift workers.

As the workforce continues to evolve, the implications of this research could inform health policies and workplace practices aimed at protecting the respiratory health of night shift workers.