A new study has found that employees who periodically work the night shift are significantly more likely to develop Type 2 diabetes.
The study, carried out by researchers from CU Boulder and Brigham and Women’s Hospital (BWH) in Boston, involved 270,000 people.
It was carried out by co-first author Celine Vetter, director of the Circadian and Sleep Epidemiology Laboratory (CASEL) at CU Boulder alongside co-first author Hassan S. Dashti and collaborators at BWH, the Broad Institute of MIT and Harvard, and Manchester University.
The study used information on lifestyle, work schedule and health status. Aged between 38 and 71, 77,000 of the participants provided in-depth lifetime employment information and a subgroup of 44,000 provided genetic information. Participants also provided information on whether they were a morning person or night person.
The researchers found that the more night shifts employees work, the greater their risks of having the disease, even if they are not genetically predisposed to it.
Published this week in the online journal Diabetes Care, the study said the reason for this is the disruption to the biological rhythms and sleep patterns of those involved.
“Shift work, particularly night shifts, disrupts social and biological rhythms, as well as sleep, and has been suggested to increase the risk of metabolic disorders, including Type 2 diabetes,” Vetter said.
“Our study is one of the first to show a dose-response relationship, where the more often people work nights, the greater their likelihood of having the disease.”
Th researchers also found that those who did not switch from day shifts to night shifts at intervals showed no increase in the incidence of diabetes. They opined that this may be because those who work the night shift gradually adapt to the schedule.
“If you rotate through a schedule that is always changing between day and night shifts it makes it hard to adapt and you can end up with a chronic misalignment between your light-dark cycle, your sleep-wake schedule, your meal timing, and your physical activity timing.”
Vetter pointed out that the effects might, however, be mitigated by maintaining a healthy weight, a healthy diet, and getting enough exercise and sleep.
Nigeria has the highest burden of diabetes in sub-Saharan Africa with over five million cases diagnosed as at 2017.