Most people wake up early on weekdays and then sleep in late during the weekends, but a new study revealed that the habitual disruption in a person's circadian rhythm or internal body clock may do more harm than good.
A sudden change in a person's routine sleep habits will increase the risks for cardio-metabolic illnesses such as Type 2 diabetes, obesity and coronary heart disease, experts said.
In a report published in the Journal of Clinical Endocrinology and Metabolism, researchers from the University of Pittsburgh looked into the mismatch between a person's internal body clock and their social schedules. This is called social jetlag.
About 447 men and women who were aged 30 to 54 years old and worked at least 25 hours a week outside their homes were involved in the study. These participants wore a wristband that recorded their sleep and movement for 24 hours in the course of seven days. They were also asked about their eating and exercise habits.
The researchers found that roughly 85 percent of the individuals slept longer on their rest days than on workdays, while the rest of the participants woke up earlier on their rest days than on workdays.
The participants with large inconsistencies in their sleep schedules on workdays and rest days had worse levels of cholesterol and fasting insulin, higher resistance to insulin, larger waist size, and greater body mass index (BMI) compared to the others.
According to a previous report by the Endocrine Society, sleep disruption is one of the factors that contribute to elevated rates of obesity and diabetes. More than 29 million Americans are diagnosed with diabetes, while 35.1 percent of American adults are obese, the report said.
Patricia M. Wong, lead author of the study, said that other studies have linked social jetlag to obesity and cardiovascular function. However, she said that this Pittsburgh study is the first to extend upon the data and show that even working and healthy adults who experience less extreme social jetlag could develop risks for metabolic problems.
"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," said Wong.
Wong suggested that clinical interventions centered on circadian disturbances could bring benefits to the public. She also added that workplace education which could help employees and their families make informed decisions about organizing their schedules, as well as policies that could encourage employers to consider these public health issues will truly help.
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