Washington, DC – Routine changes on your sleeping schedule may increase the risk of developing metabolic problems, such as diabetes mellitus and heart disease, new study says. Habits such as going early to bed and waking up early during the week, but staying up late on weekends could be potentially harmful to your health.

The study, published in the Endocrine Society’s Journal of Clinical Endocrinology & Metabolism, suggests that shift-workers are more vulnerable of developing metabolic syndrome, Type 2 diabetes and coronary heart problems than people having regular daytime jobs. Previous research say that shift-work contributes to these metabolic risks due to the disruption of the circadian system.

The circadian rhythm, a 24-hour cycle in the physiological processes of humans –also plants, fungi, and other living forms– can be modulated by external factors such as sunlight and temperature. Moreover, this irregular sleep behaviors break the harmony of this cycles, resulting in bad health consequences.

According to the Endocrine Society, sleep disruption is among the top factors that contribute to the rising numbers of diabetes and obesity in the U.S.. More than 29 million Americans suffer from diabetes, and 35.1 percent of American adults are obese. Image: spigglelaw.com

Social jet lag

Patricia Mong, from the University of Pittsburgh, explains the disruption is called “social jet lag”, stating that it is an unbalance between a person’s biological rhythm and the socially-imposed sleep schedule that they have to follow. Other researchers have found that social jet lag is linked with obesity and cardiovascular issues.

“However, this is the first study to extend upon that work and show that even among healthy, working adults who experience a less extreme range of mismatches in their sleep schedule, social jetlag can contribute to metabolic problems”, she said, according to EurekAlert.

A big disarrangement

Researchers conducted the study in a group of 447 men and women, taking part in the Adult Health and Behavior Project Phase 2 study. The patients, between ages 30 and 54, and working at least 25 hours a week outside their homes, were tested and analyzed on sleep patterns and cardiometabolic risk. Also, scientists used surveys to record diet and exercise habits.

Wong, and her colleagues, compared the sleep schedules of their patients between working days and their off-work-days -assuming that their naturally preferred sleep cycle was their free day. Results showed that all participants had a degree of social jet lag. Most of them –85 percent– stayed up later and slept in on their days off. The other 15 percent maintained their regular work schedule.

Those patients that showed the bigger misalignment on their sleeping schedules tended to show poorer cholesterol profiles, higher fasting insulin levels, obesity, higher BMI (Body Mass Index) and a higher resistance towards insulin. These results persisted when the researchers adjusted the measurements, this time taking into account other sleep measures and behaviors such as exercise and calorie intake.

Preventing further health complications

Patricia Wong warned about the possible implications of these kind of studies, stating that if these results replicate, it may be time to reconsider as a society how our work and social obligations are affecting our health.

Also, she concluded by saying that clinical interventions, workplace education and families being aware of this issue could help people deciding on how to structure their schedules.

Source:  Journal of Clinical Endocrinology & Metabolism