New research indicates that women who work night shifts are more susceptible to developing moderate to severe asthma compared to those working during the day. This heightened risk was not observed in men, as per a study published in ERJ Open Research. Dr. Robert Maidstone and his team from the University of Manchester, UK, analyzed data from over 270,000 working individuals in the UK, making it one of the largest studies exploring this association.

Asthma affects women more seriously

Dr. Maidstone highlighted that asthma impacts women disproportionately, with women often experiencing more severe symptoms, higher hospitalization rates, and increased asthma-related mortality compared to men. Previous research by the team had already indicated a higher asthma risk among night shift workers, prompting them to delve deeper into gender disparities.

What the study found

The study utilized data from the UK Biobank, a comprehensive health records database. Among the 274,541 working professionals examined, approximately 5.3% had asthma, and 1.9% had moderate to severe asthma, necessitating both a preventer inhaler and additional treatments like steroids. Participants were categorized based on their work schedules: day shift workers, night shift workers, and those with rotating shifts.

• Women working exclusively night shifts were around 50% more likely to have moderate to severe asthma compared to their day shift counterparts.
• Overall, female shift workers faced a heightened risk of asthma.
• In contrast, the asthma risk in men remained consistent regardless of their shift timings.

Why the gender difference?

While the study does not establish a definitive cause, researchers speculate that disruptions to the body's circadian rhythm due to night shifts might play a role. Hormonal factors could also contribute, with higher testosterone levels potentially offering protection against asthma. Variations in the types of shift work performed by men and women may also be a contributing factor.

Postmenopausal women at increased risk

Postmenopausal women working night shifts were nearly twice as likely to develop asthma compared to those working during the day, particularly if they were not undergoing hormone replacement therapy (HRT). This observation raises questions about the potential protective effects of HRT against asthma in night shift employees, warranting further investigation.

Future research directions

The research team plans to delve deeper into the interplay between sex hormones and shift work, leveraging additional data from the UK Biobank and Our Future Health program. Professor Florence Schleich from the University of Liege in Belgium, a lung specialist, emphasized the significance of the findings and stressed the need for more research to comprehend the link between night shift work and asthma.

Conclusion

If you are a woman working night shifts and experiencing respiratory issues, seeking medical advice is crucial. As research progresses, early detection and awareness are vital for effectively managing asthma and safeguarding long-term health.