Curiously, subjects with metabolic syndrome and type 2 diabetes, are detected to have a melatonin/insulin ratio lower than lean people, 9.64 for subjects with metabolic syndrome and type 2 diabetes and 15.36 for lean people [58], and obese nondiabetic subjects showed a night melatonin concentration higher than those of lean patients and type 2 diabetes patients [59]. Here, INS is linked to type 2 diabetes mellitus.