Receptor for body-clock hormone connected to disease risk. Diabetes – genetically linked to the body's biological clock.Punchstock Fresh evidence suggests that melatonin, a hormone that regulates the body's biological clock, is associated with type 2 diabetes. Epidemiological studies have shown that shift workers have an increased risk of developing type 2 diabetes. And patients with type 1 diabetes have sometimes reported higher blood-sugar levels after taking synthetic melatonin, which can be used to ease jet lag or as a sleep aid.Now, two separate studies by researchers based in Europe and the United States have found that variants of a gene...