November 17, 2020
2 min read
Durrington reports no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.
Adults who work permanent night shifts may have an increased risk for moderate to severe asthma, according to findings from an observational study published in Thorax.
About 20% of employees in the developed world work permanent or rotating night shifts, which can cause circadian rhythm misalignment with the external light and dark cycle. This misalignment is associated with increased risks for various metabolic disorders, cardiovascular disease and cancer, according to a press release.
Hannah J. Durrington, MA, MRCP, PhD, clinical senior lecturer in the division of infection, immunity and respiratory medicine and the Lydia Becker Institute of Immunology and Inflammation at the University of Manchester, U.K., and colleagues evaluated medical, lifestyle and employment information in the UK Biobank from 2007 to 2010 for 286,825 adults (aged 37 to 72 years). All participants were employed; 83% worked regular office hours and 17% worked varied shifts with 51% working night shifts.
Shifts included never or occasional nights shifts, irregular or rotating night shifts and permanent night shifts.
Shift workers were more likely to be men, smokers and residents of urban and more deprived areas. They drank less alcohol, slept more and worked longer hours compared with participants working office hours, the release stated. Night-shift workers more often reported a preference for evening activity — being a “night owl” — and they tended to have poorer health than those who worked daytime hours. They were also more likely to work in service jobs or as process, plant and machine operatives. Participants working office hours were more likely to be in administrative positions and to have professional jobs.
Asthma was observed in 14,238 (5%) participants, and 4,783 (2%) of participants reported symptoms of moderate to severe asthma, according to the release. After adjusting for other risk factors, researchers observed a 36% increase in the odds of having moderate to severe asthma in permanent night-shift workers compared with participants working office hours.
Those working any of the three shift patterns compared with regular office hours had increased odds of wheeze (11%) or airway whistling (18%). Those who never or rarely worked nights or permanent night shifts had increased odds for poorer lung function (20%), the release stated.
Those known as extreme chronotypes with a preference for morning or evening activity had a significantly higher likelihood for asthma, even after adjusting for risk factors. Among those with a preference for morning activity who worked irregular shift patterns, the odds of moderate to severe asthma were 55% higher, according to the release.
“The public health implications of our findings are potentially far-reaching since both shift work and asthma are common in the industrialized world,” the researchers said in the release. “There are no specific national clinical guidelines for how to manage asthma in shift workers,” they said, adding that “adapting shift work schedules to suit individual chronotype might be a worthwhile public health measure that is worth exploring further.”