WASHINGTON, April 2 – A decrease in levels of the sleep hormone melatonin has been linked to an increased risk of adult onset diabetes, according to a study published Tuesday.

Research in the Journal of the American Medical Association reported that 370 women with diabetes were compared with 370 women of the same race and age without the disease.

Researchers found participants with diabetes produced low levels of melatonin at night compared to the control group without diabetes.

Melatonin is produced by the brain during sleep, when its levels are higher in blood, to help regulate the circadian rhythm or "body clock."

"This is the first time that an independent association has been established between nocturnal melatonin secretion and type two diabetes risk," said Ciaran McMullan, a researcher in the Renal Division and Kidney Clinical Research Institute at Brigham and Women's Hospital, Boston.

The research found that participants who produced a low level of melatonin at night were twice as likely to develop diabetes compared to those who produced a high level of the hormone.

Melatonin secretion varied sharply between the participants, with some producing nearly five times as much as the lowest.