An estimated 15 million Americans do some kind of rotating shift work, including overnights, evenings, and early morning shifts. But can this type of shift work increase the risk of coronary heart disease? A new study examined the link between rotating night shift work and heart disease in a group of female nurses.

Researchers at Brigham and Women’s Hospital used data from the Nurses’ Health Studies (1 and 2), which followed participants for a twenty-four year period. They specifically looked at 189,000 women who reported their lifetime exposure to rotating night shift work. Over the course of the study period, more than 10,000 new cases of coronary heart disease were reported.

The results suggested that rotating night shift work was associated with modest risk of coronary heart disease, but further research is needed to help determine whether the association is related to specific work hours and/or individual characteristics.

Click here to review the study published in JAMA, Journal of the American Medical Association.