Night shifts plus unhealthy lifestyle increase diabetes risk in women

Both rotating night shift work and an unhealthy lifestyle are linked with increased risk of type 2 diabetes in women, according to a new study from Harvard T.H. Chan School of Public Health. But when both factors are present the risk is even greater than simply adding together the effects of each individually.

Researchers looked at data from more than 143,000 women enrolled in the Nurses’ Health Study and the Nurses’ Health Study II. They found that every five years of rotating night shift work increased women’s risk of type 2 diabetes by roughly 30%, and that having a combination a several unhealthy lifestyle factors—such as smoking or having a poor diet—more than doubled the risk, according to a November 23, 2018 Medscape article.

But women who worked rotating night shifts for more than five years and who also had an unhealthy lifestyle were 2.83 times more likely than women without these factors to develop type 2 diabetes. The two factors together accounted for 11% of additional risk.

The researchers said their findings suggest that most cases of type 2 diabetes could be prevented by maintaining a healthy lifestyle, and that the benefits would be greater in people who work rotating night shifts.

Harvard Chan researchers involved with the study included lead author Zhilei Shan, Yanping Li, Geng Zong, Yanjun Guo, Jun Li, JoAnn Manson, Frank Hu, Walter Willett, Eva Schernhammer, and Shilpa Bhupathiraju.

Read the Medscape article: Night Shifts and Unhealthy Lifestyle Combine to Up Risk of Diabetes

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Rotating night shift work linked to increased risk of type 2 diabetes in women (Harvard Chan School release)