08 Oct 2015 --- Researchers from Brigham and Women's Hospital (BWH) and the University of Murcia, Spain, have shed new light on why people who carry a common genetic mutation may be more at risk for developing type 2 diabetes. By carefully studying healthy subjects, researchers were able to chart the effect of melatonin supplements on blood sugar control. Their results, reported in Metabolism, suggest that taking melatonin close to mealtimes may put people with a common genetic variant more at risk.