Doctors have long extolled the health values of getting eight hours of sleep every night. Add another benefit to the list: new research shows that getting eight and a half hours of sleep every night could reduce the risk of developing Type 2 diabetes in teenagers who are obese. The findings were published in the journal “Diabetes Care.”

The study was conducted on 62 teenagers. The results demonstrated that insulin and blood sugar levels stayed at optimum levels for those who got between seven and a half and eight and a half hours of sleep at night. Getting more or less sleep increased the chance of elevated blood glucose levels; getting less than seven and a half hours of sleep resulted in lowered insulin levels.

According to the research team, which is affiliated with Children’s Hospital of Philadelphia, the results of the study demonstrate that healthy sleeping patterns could be beneficial in warding off diabetes in the participants of the study, who were all obese. The study was headed by Dr. Dorit Koren, who commented that the results corresponded with previous research showing that sleep-deprived adults were at a higher risk of developing Type 2 diabetes.

The study was conducted over a period of one and a half days. The teenagers’ blood sugar levels were monitored throughout the investigation, while their sleeping patterns were tracked and analyzed by the research team.

“Our study found to keep glucose levels stable, the optimal amount of sleep for teenagers is 7.5 to 8.5 hours per night,” said Dr. Koren.

The research team plans to conduct additional research, this time in the teenagers’ own homes rather than in a laboratory, to back up the results of the study.

“In the meantime, our study reinforces the idea that getting adequate sleep in adolescence may help protect against type 2 diabetes,” says Dr. Koren.

Research has shown that teenagers are not getting enough sleep. Another study previously conducted in 2007 showed that one in three British teenagers is getting just four to seven hours of sleep every night.

Another study conducted at the University of Buffalo and headed by Lisa Rafalson found that participants who were sleep-deprived were 4.5 times more likely to develop impaired fasting glucose, a condition that is considered a precedent to Type 2 diabetes. The study analyzed data from 1,455 volunteers over a period of six years; it measured how long the participants slept on average on weeknights. Participants who got less than six hours a night were four times more likely to develop impaired fasting glucose than participants who regularly got six to eight hours of sleep a night. The study’s findings were presented at the 49th annual Conference on Cardiovascular Disease Epidemiology of the American Heart Association in Palm Harbor, Florida.

“Our findings will hopefully spur additional research into this very complex area of sleep and illness,” said Rafalson. “While previous studies have suggested that there may be many genes that each have a very small effect on the risk of diabetes, there is no known genetic predisposition to sleep disturbances that could explain our study’s results, especially in this limited sample size. It is more likely that pathways involving hormones and the nervous system are involved in the association.”

It is speculated by some researchers that a lack of deep sleep is the source of the increased risk of diabetes: a shortage of slow-wave, or deep sleep, impairs the body’s ability to regulate blood glucose levels and increases risk of Type 2 diabetes.