<qa>  What is the main limiting factor in gaining tight control of blood sugar?The Diabetes Control and Complications Trial DCCT showed that improving blood sugar control for individuals with Type 1 diabetes T1DM stopped or delayed the onset of long-term health problems. Insulin management is aimed to control blood sugar as near to normal as safely possible. However, the possibility of low blood sugars still remains. Low blood sugars the major limiting factor in gaining tight control of blood sugar. Insulin the hormone that lowers blood sugar and glucagon hormone that raises blood sugar play a key role in keeping this careful balance. There is a lack of insulin and failure of glucagon to work correctly in diabetes. This leads to high blood sugars right after a meal. 