Diabetes 2 linked to sleep cycles

MUNICH, Germany, Jan. 19 (UPI) -- International researchers identified a gene variant linked to elevated fasting glucose levels and a high risk for type 2 diabetes, a German researcher said.

Thomas Illig of Helmholtz Zentrum Munchen in Germany said that the gene mediates insulin secretion indirectly via the release of melatonin, which implicates a previously unknown relationship between the sleep-wake rhythm and the fasting glucose level. The finding could open up new possibilities of treatment which go far beyond the primarily symptomatic therapy approaches to diabetes that have been practiced until now, the study said.

The international Meta-Analyses of Glucose and Insulin-related traits Consortium Consortium combined the data from 13 case-control studies with over 18,000 diabetic and 64,000 non-diabetic study participants and was able to identify a variant of the MTNR1B gene which is associated with both elevated fasting glucose levels as well an elevated risk for type 2 diabetes.

The MTNR1B gene is active in insulin-producing islet cells and it is assumed that this receptor inhibits the release of insulin via the neural hormone melatonin. The melatonin level in the body is high at night and declines in daylight, whereas the insulin level is higher during the day than in the night.

Taken together, these data, published in Nature Genetics, implicates an association between the sleep-wake rhythm, the so-called circadian rhythm, and fasting glucose levels.