Changes in Sleep Cycle Might Affect Health

A significant difference between sleep schedules we naturally prefer and those imposed by society – what researchers term “social jetlag” – has been linked with elevated cardiometabolic risks that can contribute to diabetes, obesity and cardiovascular disease, researchers say.

Health experts have always been aware of the fact that alternate shifts disrupt the body’s circadian rhythm and that shift work contributes to development of diseases like diabetes and obesity.

Researchers also took blood samples and used questionnaires to gather data on the participants’ exercise and diet habits.

Almost 85 percent slept in more on free days compared to work days – a practice known as midsleep or “later halfway point in sleep cycle”. According to the press release, those with with biggest shifts in sleep schedule also had worse cholesterol, a higher BMI, a larger waist circumference, and more.

The association persisted even when the researchers adjusted the measurements to account for variation in other sleep measures and health behaviors, such as physical activity and calorie intake. The researchers claim sleeping late on days off cause’s metabolic health problems.

Dr. Wong believes that if her team’s findings are confirmed by future studies, we should pay more attention to the implications of our social obligations on our sleep and health.

Wong said further research in the area would be required to establish that changes to sleep habits could help people lead healthier lives. So if your daily routine is waking up daily after five in the morning, then you must avoid “oversleeping” on days off or weekend – if you don’t want to develop heart disease or diabetes. All the participants worked part- or full-time day shifts outside the home for at least 25 hours per week. In order to be under 24/7 surveillance, the participants were given a wristband measuring sleep and movement.

Earlier this month, MNT reported on a study that suggested a single night’s sleep deprivation may increase the risk for insulin resistance. BMI is an estimate of body fat based on height and weight.

The study was published Wednesday in the Journal of Clinical Endocrinology & Metabolism. The sleep disturbance damages the metabolic cycles and circadian rhythm synchronization in the body. “Other researchers have found that social jetlag relates to obesity and a few indicators of cardiovascular function”, said Patricia M. Wong, MS, of the University of Pittsburgh in Pittsburgh, PA.

Wong said this study was the first to extend the investigation into the link of social jetlag on healthy people, and revealed that the condition can cause problems even among healthy working adults.

Study authors explained that social jet lag, or the changes in sleep schedule that most people are exposed to on their days off, remained tied to a high risk of metabolic disorders and heart disease even after adjustments were made.