INS and diabetes mellitus: The GK rats, non-obese diabetic animals with low insulin secretion, are the relevant animal model suitable for studying the human type 2 diabetes.(2,10) Since intensive glycemic control is the major goal in treatment of diabetes and essential for reducing the risk of diabetic complications,(11) it is worth studying the effect of soy isoflavones on glycemic control in GK rats with type 2 diabetes.