Long-term Night Shift Work Linked with Risk for Atrial Fibrillation and Coronary Heart Disease

Investigators have found that night shift workers are significantly more likely to develop atrial fibrillation (AF) and coronary artery disease (CAD), independent of genetic risk.1

Shift work has allowed operations to exceed the length of a workday and prevents interruption in crucial services. The Bureau of Labor Statistics reports that over 21 million Americans have non-daytime shifts, predominantly in the health, food, manufacturing, and transportation industries.2

Previous research has demonstrated marked increases in cardiovascular and all-cause mortality among night shift workers, as well as risk of myocardial infarction, particularly among those working night shifts for >5 years.3,4

A study of more than 283,000 individuals in the UK Biobank database is the first to address the association between night shift work and AF.

Professor Ningjian Wang and colleagues found that longer duration of shifts and greater cumulative night shift exposure were both associated linearly with increased risk of AF. Usual or permanent night shift workers had a 12% increased risk of AF compared to day shift workers, increasing to 18% after ten or more years of cumulative night shifts. Genetic risk, on the basis of 166 genetic variations associated with AF, did not modify the association between night shift work and AF risk. An increased risk of CAD was also demonstrated, though there was no significant increase in heart failure or stroke incidence. Analyses were adjusted for demographics including socioeconomic status and tobacco use.

Interestingly, Wang and colleagues found a stronger association between night shifts and AF among women and physically inactive individuals. Professor Lu Qi of Tulane University School of Public Health and Tropical Medicine commented that for women, “their risk increased significantly by 64% compared to day workers. People reporting an ideal amount of physical activity… had a lower risk of AF than those with non-ideal physical activity when exposed to a lifetime of night shift work. Thus, women and less physically active people may benefit particularly from a reduction in night shift work.”

Professor Yingli Lu stated “our findings have public health implications for preventing atrial fibrillation. They suggest that reducing both the frequency and the duration of night shift work may be beneficial for the health of the heart and blood vessels.”

Though observational data cannot elucidate a causal link, Wang and colleagues pave the way for future research to address primary prevention of AF and whether reduction in night shift work may improve cardiac outcomes.

Author Jessie Holtzman, MD, is a correspondent with the CardioNerds and a contributor to DocWire News. Follow her on Twitter @jholtzman3.

References

1. Wang N, Sun Y, Zhang H, et al. Long-term night shift work is associated with the risk of atrial fibrillation and coronary heart disease. Euro Heart J. 2021;doi.org/10.1093/eurheartj/ehab505

2. McMenamin TM. A time to work: recent trends
in shift work and flexible schedules. Monthly Labor Review. Bureau of Labor Statistics. 2007.

3. Gu F, Han J, Laden F, et al. Total and cause-specific mortality of U.S. nurses working rotating night shifts. Am J Prev Med. 2015;48(3):241-252.

4. Vyas MV, Garg A,X Iansavichus AV. Shift work and vascular events: systematic review and meta-analysis. BMJ. 2012;345:e4800.