Sleep Schedule Disruption May Increase Diabetes Risk

Shifts in sleep schedules may increase an individual's risk for diabetes.

Shifts in sleep schedules may increase an individual’s risk for diabetes.

A new study examined the role of “social jetlag” in predisposing individuals to diabetes and heart disease. Social jetlag was defined as the clash between a person’s biological circadian rhythm and their actual sleep habits, which can be affected by social obligations.

Researchers from the University of Pittsburgh observed nearly 450 healthy middle-aged adults who worked part- or full-time day shifts in order to assess how work schedules can affect day-to-day circadian dysregulation.

The participants were between the ages of 30 and 54 and worked at least 25 hours per week outside the house.

The participants wore wristbands that monitored movement and sleep for 24 hours a day for an entire week. The participants also completed a questionnaire that asked about their diet and exercise habits.

The majority of study participants (almost 85%) had a later halfway point in their sleep cycle on their free days compared with their workdays. The remaining 15% had an earlier halfway point on free days compared with workdays.

The researchers found that the participants with greater disjointedness between their sleep schedules on free versus working days tended to have poorer cholesterol profiles, higher fasting insulin levels, larger waist circumference, and higher body mass index. They were also more likely to be resistant to insulin.

These findings remained true even when the researchers adjusted for factors like varying sleep measures, physical activity, and caloric intake.

“…[E]ven among healthy, working adults who experience a less extreme range of mismatches in their sleep schedule, social jetlag can contribute to metabolic problems,” said Patricia M. Wong, MS, of the University of Pittsburgh, in a press release. “These metabolic changes can contribute to the development of obesity, diabetes, and cardiovascular disease.”

The researchers said they would like to see other investigative teams replicate their findings in the future. A replication would indicate that there is a need to examine how modern work and social obligations affect sleep and health, the researchers said.

“There could be benefits to clinical interventions focused on circadian disturbances, workplace education to help employees and their families make informed decisions about structuring their schedules, and policies to encourage employers to consider these issues,” Wong said in a press release.

Previous research found that social jetlag can influence obesity and can be an indicator of cardiovascular function, as well.

“Our results, along with other recent reports, suggest that a misalignment of the biological and socially influenced sleep timing is an additional factor contributing to risk for developing obesity, type 2 diabetes, and atherosclerotic cardiovascular disease and highlight the potential for sleep and circadian-focused interventions in preventative health care,” the researchers concluded.

These findings were published in The Journal of Clinical Endocrinology & Metabolism.