Not getting enough sleep may disrupt blood sugar levels, a study of obese teens suggests.

For the study reported on in Tuesday's issue of the journal Diabetes Care, researchers studied 62 obese U.S. teens with an average age of 14. The optimal amount of sleep for teenagers is about 7.5 to 8.5 hours per night, researchers say. iStock

The teens participated in the overnight sleep study so scientists could analyze their stages of sleep and glucose levels.

Getting too much or too little sleep was associated with higher glucose levels, researchers found.

"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. Dorit Koren, an author of the study and a pediatric endocrinologist at Children's Hospital of Philadelphia.

Research on adults also suggests an association between sleep deprivation and increased risk of Type 2 diabetes, the study's authors noted.

Getting less deep sleep was also linked with decreased insulin secretion in the teens.

Next, the researchers plan to look at the sleep patterns of obese teenagers at home.

The study was funded by the Pennsylvania State Tobacco Settlement Fund and the U.S. National Institutes of Health's National Center for Research Resources.