Weekday sleep changes may raise risk of diabetes, heart disease

http://www.eurekalert.org/pub_releases/2015-11/tes-wsc111315.php

Public Release: 18-Nov-2015
Weekday sleep changes may raise risk of diabetes, heart disease
Study first to find link between social jet lag, metabolism
The Endocrine Society

Monday mornings could be harmful to your health. Even routine sleep changes such as waking up early for work during the week may raise the risk of developing metabolic problems such as diabetes and heart disease, according to a new study published in the Endocrine Society's Journal of Clinical Endocrinology & Metabolism.

Researchers have long recognized that shift work can contribute to metabolic risk because of the continual disruption to the circadian system. Shift workers are more likely to develop metabolic syndrome, coronary heart disease and Type 2 diabetes than employees with regular daytime shifts.

Sleep disruption is among the factors that have contributed to rising rates of diabetes and obesity. More than 29 million Americans have diabetes, and 35.1 percent of American adults are obese, according to the Endocrine Society's Endocrine Facts and Figures report.

"Social jetlag refers to the mismatch between an individual's biological circadian rhythm and their socially imposed sleep schedules. Other researchers have found that social jetlag relates to obesity and some indicators of cardiovascular function," said Patricia M. Wong, MS, of the University of Pittsburgh in Pittsburgh, PA. "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. These metabolic changes can contribute to the development of obesity, diabetes and cardiovascular disease."

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Participants who had a greater misalignment between their sleep schedules on free and work days tended to have poorer cholesterol profiles, higher fasting insulin levels, larger waist circumference, higher body-mass index and were more resistant to insulin than those who had less social jetlag. 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.

"If future studies replicate what we found here, then we may need to consider as a society how modern work and social obligations are affecting our sleep and health," Wong 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."