"Night Shift" by Yuchung Chao is licensed under CC BY-ND 3.0

Rotating Night Shift Work Adds To Risk of Type II Diabetes

MedicalResearch.com Interview with:

"Night Shift" by Yuchung Chao is licensed under CC BY-ND 3.0Dr. Zhilei Shah PhD
Department of Nutrition and Food Hygiene, Hubei Key Laboratory of Food Nutrition and Safety
Ministry of Education Key Lab of Environment and Health, School of Public Health
Tongji Medical College, Huazhon
University of Science and Technology
Wuhan,  China

MedicalResearch.com: What is the background for this study?

Response: Shift work has progressed in response to changes in economic pressure and greater consumer demand for 24-hour services. There are many economic advantages to increased shift work, including higher employment, increased services to customers, and improved trade opportunities. Currently, one in five employees in the U.S. works nonstandard hours in the evening, night, or rotating shifts. However, shift work, especially night shift work, has been associated with a higher risk of chronic diseases, including type 2 diabetes, cardiovascular disease, and several types of cancer.

Compelling evidence has shown that body weight and lifestyle behaviors, such as smoking, diet, and physical activity can influence type 2 diabetes risk. Among shift workers, excess adiposity and increased smoking are frequently and consistently reported, whereas the evidence on physical activity and diet is mixed. Additionally, no previous study has examined the joint associations of rotating night shift work duration and unhealthy lifestyle factors with risk of type 2 diabetes, or evaluated their potential interactions.

Therefore, we prospectively assessed the joint association of rotating night shift work and established type 2 diabetes lifestyle risk factors with risk of type 2 diabetes and quantitatively decomposed the proportions of the joint association to rotating night shift work alone, to lifestyle alone and to their interaction in two large US cohorts.

MedicalResearch.com: What are the main findings?

Response: We found that rotating night shift work duration and unhealthy lifestyle (ever smoking, a low diet quality, low physical activity, and overweight or obese) were independently and jointly associated with a higher risk of type 2 diabetes. The proportions of the joint association were 17% for rotating night shift work duration alone, 71% for unhealthy lifestyle alone, and 11% for an additive interaction between rotating night shift work duration and unhealthy lifestyle. Our findings highlight the additive interaction between rotating night shift work and unhealthy lifestyle on type 2 diabetes risk. In particular, if both rotating night shift work and unhealthy lifestyle were present, this would result in an additional 11% of type 2 diabetes cases. From a public health standpoint, because 71% of the joint effect could be attributed to an unhealthy lifestyle, our findings underscore the importance of maintaining a healthy lifestyle.

MedicalResearch.com: What should readers take away from your report?

Response: Most cases of type 2 diabetes could be prevented by adherence to a healthy lifestyle, and the benefits could be larger in rotating night shift workers.

MedicalResearch.com: What recommendations do you have for future research as a result of this work?

Response: Further studies are warranted to replicate our findings in other populations and clarify the underlying mechanisms. Randomized controlled trials are needed to establish the effect of lifestyle intervention on risk of type 2 diabetes among shift workers.  

MedicalResearch.com: Is there anything else you would like to add?

Response: Our observational study is unable to draw conclusions about cause and effect.  

Any disclosures? No conflicts of interest.


Rotating night shift work and adherence to unhealthy lifestyle in predicting risk of type 2 diabetes: results from two large US cohorts of female nurses

BMJ 2018363 doi: https://doi.org/10.1136/bmj.k4641 (Published 21 November 2018)Cite this as: BMJ 2018;363:k4641[wysija_form id=”3″]


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Last Updated on November 24, 2018 by Marie Benz MD FAAD