FRIDAY, Nov. 30, 2018 (HealthDay News) -- Both rotating night shift work and unhealthy lifestyle are associated with an increased risk for type 2 diabetes among female nurses, with a significant additive interaction, according to a study published online Nov. 21 in the BMJ.
Zhilei Shan, Ph.D., from Tongji Medical College in Wuhan, China, and colleagues conducted a prospective cohort study to examine the joint association of duration of rotating night shift work and lifestyle factors with type 2 diabetes risk. Participants included 143,410 women without type 2 diabetes, cardiovascular disease, or cancer at baseline from the Nurses' Health Study and Nurses' Health Study II.
The researchers identified 10,915 cases of incident type 2 diabetes during 22 to 24 years of follow-up. The multivariable-adjusted hazard ratios for type 2 diabetes were 1.31 and 2.3 per five-year increment of duration of rotating night shift work and per unhealthy lifestyle factor, respectively. The hazard ratio was 2.83 for the joint association of per-five-year-increment rotating night shift work and per unhealthy lifestyle factor with type 2 diabetes, with a significant additive interaction (P for interaction < 0.001). The proportions of the joint association were 17.1, 71.2, and 11.3 percent for rotating night shift work alone, unhealthy lifestyle alone, and their additive interaction, respectively.
"These findings suggest that most cases of type 2 diabetes could be prevented by adherence to a healthy lifestyle, and the benefits would be larger in rotating night shift workers," the authors write.