Study shows the night shift’s impact on diabetes and obesity risks

Richland, WA — Spending just three days working a night shift “can knock the body’s biological rhythms off course, disrupting important processes related to blood glucose regulation, energy metabolism and inflammation,” researchers from Washington State University and the Pacific Northwest National Laboratory say.

The team asked volunteers to take part in simulated night or day shift schedules for three days. Participants were then kept awake for 24 hours to analyze proteins in immune system cells that are closely tied to the body’s master biological clock. 

Blood samples were drawn from the participants at regular times throughout the study. They showed that among the participants in the night shift group, proteins involved in regulation of glucose exhibited “a nearly complete reversal of glucose rhythms.” In addition, processes involved in insulin production and sensitivity weren’t synchronized as usual.

This misalignment, the researchers say, “is associated with a tug-of-war between central clock mechanisms controlling insulin secretion and peripheral clock mechanisms regulating insulin sensitivity.” 

These changes could signal why night shift workers are more prone to obesity, diabetes and other metabolic health disorders.

“There are processes tied to the master biological clock in our brain that are saying that day is day and night is night and other processes that follow rhythms set elsewhere in the body that say night is day and day is night,” said senior study author Hans Van Dongen, a professor in WSU’s Elson S. Floyd College of Medicine. “When internal rhythms are dysregulated, you have this enduring stress in your system that we believe has long-term health consequences.”

The study was published online in the Journal of Proteome Research.