Too little sleep, disrupted internal clock means higher risk of diabetes and obesity

A study by researchers at Brigham and Women's Hospital (BWH) reinforces the finding that too little sleep or sleep patterns that are inconsistent with our body's "internal biological clock" may lead to increased risk of diabetes and obesity. This finding has been seen in short-term lab studies and when observing human subjects via epidemiological studies. However, unlike epidemiological studies, this new study provides support by examining humans in a controlled lab environment over a prolonged period, and altering the timing of sleep, mimicking shift work or recurrent jet lag.

The study will be electronically published on April 11, 2012 in Science Translational Medicine.

Researchers hosted 21 healthy participants in a completely controlled environment for nearly six weeks. The researchers controlled how many hours of participants got, as well as when they slept, and other factors such as activities and diet. Participants started with getting optimal sleep (approximately 10 hours per night). This was followed by three weeks of 5.6 hours of sleep per 24-hour period and with sleep occurring at all times of day and night, thereby simulating the schedule of rotating shift workers. Thus, during this period, there were many days when participants were trying to sleep at unusual times within their internal —the body's "internal biological clock" that regulates sleep-wake and many other processes within our bodies. The study closed with the participants having nine nights of recovery sleep at the usual time.

The researchers saw that prolonged sleep restriction with simultaneous circadian disruption decreased the participants' resting metabolic rate. Moreover, during this period, glucose concentrations in the blood increased after meals, because of poor insulin secretion by the pancreas.

According to the researchers, a decreased resting metabolic rate could translate into a yearly weight gain of over 10 pounds if diet and activity are unchanged. Increased glucose concentration and poor insulin secretion could lead to an increased risk for diabetes.

"We think these results support the findings from studies showing that, in people with a pre-diabetic condition, who stay awake at night are much more likely to progress to full-on than day workers," said Orfeu M. Buxton, PhD, BWH neuroscientist and lead study author. "Since night workers often have a hard time sleeping during the day, they can face both circadian disruption working at night and insufficient sleep during the day. The evidence is clear that getting enough sleep is important for health, and that sleep should be at night for best effect."

Related Stories

Rotating shift workers have lower levels of serotonin

Aug 01, 2007

People who work rotating shifts have significantly lower levels of serotonin, a hormone and neurotransmitter in the central nervous system believed to play an important role in the regulation of sleep, according to a study ...

Night shift nurses more likely to have poor sleep habits

Jun 11, 2007

Nurses who work the night shift are more likely to have poor sleep habits, a practice that can increase the likelihood of committing serious errors that can put the safety of themselves as well as their patients at risk, ...

Recommended for you

Can YouTube save your life?

18 hours ago

Only a handful of CPR and basic life support (BLS) videos available on YouTube provide instructions which are consistent with recent health guidelines, according to a new study published in Emergency Medicine Australasia, the jo ...

Doctors frequently experience ethical dilemmas

19 hours ago

(HealthDay)—For physicians trying to balance various financial and time pressures, ethical dilemmas are common, according to an article published Aug. 7 in Medical Economics.

AMGA: Physician turnover still high in 2013

19 hours ago

(HealthDay)—For the second year running, physician turnover remains at the highest rate since 2005, according to a report published by the American Medical Group Association (AMGA).

Obese or overweight teens more likely to become smokers

20 hours ago

A study examining whether overweight or obese teens are at higher risk for substance abuse finds both good and bad news: weight status has no correlation with alcohol or marijuana use but is linked to regular ...

Taking preventive health care into community spaces

21 hours ago

A church. A city park. An office. These are not the typical settings for a medical checkup. But a new nationwide study by the UCLA Center for Health Policy Research shows that providing health services in ...

User comments