A few days working night shifts can disrupt protein rhythms linked to energy metabolism, blood glucose control, and inflammation—processes that can have an impact on the emergence of chronic metabolic disorders.
The discovery, which came from a study headed by researchers at Pacific Northwest National Laboratory and Washington State University, offers fresh insights into the reasons for the higher risk of diabetes, obesity, and other metabolic problems among night shift workers.
Senior study author Hans Van Dongen, a professor at WSU Elson S. Floyd College of Medicine, said, “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.” “When internal rhythms are dysregulated, you have this enduring stress in your system that we believe has long-term health consequences.”
Van Dongen stated that although further research is required, the study demonstrates that these disturbed cycles can be observed in as little as three days, indicating that early intervention to avoid obesity and diabetes may be feasible. A similar technique may also help reduce the risk of heart disease and stroke, both of which are more common in night shift workers.
The study, which was published in the Journal of Proteome Research, featured three days of controlled laboratory work where volunteers were assigned to either a day shift or a night shift. To assess the participants’ internal biological cycles without outside intervention, they were kept awake for a whole day under consistent settings, including lighting, temperature, posture, and food intake, after their last shift.
Throughout the course of the 24-hour period, blood samples taken at regular intervals were examined to see which proteins were found in blood-based immune system cells. Certain proteins have rhythms that were closely linked to the body’s 24-hour master biological clock. These protein rhythms were not significantly affected by the night shift schedule because the master clock is robust to changes in shift schedules.
When comparing the night shift individuals to the day shift participants, the rhythms of the majority of other proteins showed significant changes.
Upon closer inspection of the proteins involved in glucose control, the researchers saw that the individuals working the night shift had almost entirely reversed their glucose cycles. Researchers also discovered that in night shift participants, there was a disruption in the synchronization of processes related to insulin sensitivity and production, which typically cooperate to maintain blood glucose levels within a healthy range. According to the researchers, this impact might be the result of insulin attempting to reverse the glucose alterations brought on by working night shifts. According to them, while this might be a good reaction in the short term due to the possibility of organ and cell damage from changed glucose levels, it might not be in the long run.
According to Jason McDermott, a computational scientist from PNNL’s Biological Sciences Division, “what we showed is that we can really see a difference in molecular patterns between volunteers with normal schedules and those with schedules that are misaligned with their biological clock.” “The effects of this misalignment had not yet been characterized at this molecular level and in this controlled manner before.” The researchers’ next step will be to study real-world workers to determine whether night shifts cause similar protein changes in long-term shift workers.