Study: Type 2 Diabetes Risk Linked to Melatonin Levels

April 2013 - Millions of Americans are diagnosed with type 2 diabetes, yet scientists are still puzzled as to the exact causes of diabetes. Now, new research finds that the amount of melatonin a person secretes during sleep may predict their risk of developing type 2 diabetes. The study appeared in the April 3, 2013 issue of JAMA.

"This is the first time that an independent association has been established between nocturnal melatonin secretion and type 2 diabetes risk," said Dr. Ciaran McMullan, a researcher in the Renal Division and Kidney Clinical Research Institute at Brigham and Women's Hospital (BWH).

"Hopefully this study will prompt future research to examine what influences a person's melatonin secretion and what is melatonin's role in altering a person's glucose metabolism and risk of diabetes." Melatonin is a hormone that is produced by the brain and secreted into a person's bloodstream. As melatonin is mainly produced at night, melatonin's blood levels peak during the nightime allowing regulation of circadian rhythm.

For this study, researchers identified 370 women who developed diabetes while taking part in the Nurses' Health Study and 370 control subjects of the same age and race. When the two groups were compared, researchers found the study participants with low levels of nocturnal melatonin secretion had about twice the risk of developing type 2 diabetes than participants with high levels of nocturnal melatonin secretion.

The study accounted for other well-established risk factors for diabetes, such as body mass index, family history of diabetes and lifestyle factors including diet, exercise, smoking and sleep duration and still found that melatonin secretion remained a significant risk factor.

This research was supported by National Institutes of Health grants DK58845 and HL103607.

Source: National Institutes of Health