Shift work: A diabetes hazard?

Engaging in shift work can put individuals at risk of developing diabetes regardless of their lifestyle, body mass index, and prediabetes status, a study from Japan suggests.

To address the limited data on how shift work might affect the development of type 2 diabetes, especially among workers at high risk, researchers conducted a prospective study that included 17,515 Japanese workers aged 40–78 years.

The participants attended annual health examinations for about 8 years, during which they reported whether they were currently engaged in shift work. Diabetes was assessed using fasting plasma glucose, random glucose, HbA1c, and self-reported use of antidiabetic medications.

Over a median follow-up of 8.1 years, 2,071 incident cases of diabetes occurred. The rates were much higher in the group of participants who engaged in shift work vs those who had nonshift work.

Cox proportional hazards regression analysis revealed that shift work was associated with a 19-percent increase in the risk of developing diabetes (hazard ratio, 1.19, 95 percent confidence interval [CI], 3–37). The estimate was controlled for demographic, cardiometabolic, and work-related factors.

On further analysis, with adjustment for lifestyle factors and body mass index, shift work remained associated with a risk increase, with no material change in the estimate (HR, 1.16, 95 percent CI, 1–34).

The association was replicated among workers with prediabetes.