Type 1 diabetes mellitus (T1DM) is characterized by immune mediated beta-cell destruction. Due to the imbalance between glucagon and insulin, long-term T1DM patients experience frequent hypoglycaemia and high glucose variability despite of multiple daily injections of insulin.~Dipeptidyl peptidase 4 (DPP-4) inhibitors are a new class of anti-diabetic agents and are widely used in clinical practice to improve glycemic control and protect β-cell function in patients with type 2 diabetes mellitus(T2DM). Saxagliptin, a DPP-4 inhibitor, improves glycemic control in patients with T2DM by increasing endogenous active, intact glucagon-like peptide 1 and glucose-dependent insulinotropic polypeptide in response to food, which augments insulin secretion and decreases glucagon release. This mechanism can lead to the reduction of glucose variation. In some pilot studies, incretin-based therapy in patients with T1DM can improve glucose control and reduce hypoglycemia, the mechanism probably is that it regulates glucagon level. In type 1 diabetic mouse models, DPP-4 inhibitors preserves beta-cell mass and stimulating beta-cell replication.~Interestingly, DPP-4 is also known as cluster of differentiation antigen 26(CD26).It is expressed on the membrane of many types of lymphocyte, e.g. T, B and natural killer(NK)cells, and is involved in their cellular functions. CD26 plays a key role in many aspects in lymphocyte function beyond its DPP-4 enzymatic activity.These observations make it a promising therapeutic target.~Recently, the attention of saxagliptin has been mainly focused on type 2 diabetes, data in type 1 diabetes is rare. We are going to carry out this phase 4 study to testify our hypothesis that saxagliptin could reduce the fluctuation of glycemia and improve the glycemic control in those type 1 diabetes through mechanisms of suppressing glucagon secretion, improving beta cell function, and re-regulating of the T cell immune system.
To investigate whether saxagliptin could reduce the fluctuation of glycemia and improve the glycemic control in those type 1 diabetes through mechanisms of suppressing glucagon secretion, improving beta cell function, and re-regulating of the T cell immune system.