To compare the effect of the rapid-acting insulin analogues (RAIAs) NovoRapid (aspart) and Prandilin (lispro) on glycemic variations by Continuous glucose monitoring system (CGMS) in continuous subcutaneous insulin infusion (CSII) with metformin intensive therapy in newly diagnosed type 2 diabetes mellitus (T2DM).

The study was designed as a single blind randomized control trial. A total of 110 newly type 2 diabetic diagnosed patients with hemoglobin A1c (HbA1c%) above 9% were hospitalized, and were randomly divided into two groups: NovoRapid group (group Asp) and Prandilin group (group Lis) in CSII, combined with metformin therapy. Treatments were maintained for 2-3 weeks after the glycaemic target was reached. To complete the assessment of general information, fasting C-peptide (C-P0), 2-h postprandial C-peptide (C-P2h), fasting insulin (Ins0), 2-h postprandial insulin (Ins2h), HbA1c% and fructosamine on the baseline and endpoint. 4 days continuous glucose monitoring (CGM) was performed on after three days stable glucose.

Inclusion Criteria:

1. voluntary to attend this study signed the informed consent; 2. between 18 and 75 years of age; 3. according to the who standards, the subjects should be newly diagnosed as type 2 diabetes; 4. BMI between 19 and 35kg/m2; 5.HbA1c>9%; 6. using enough contraception and not pregnancy; 7. The patients do not attend any medical subjectsin in the last 3 months before enrollment; 8. the subjects agreed to maintain the original diet and exercise habits throughout the study period.

Exclusion Criteria:

1. Patients with severe cardiopulmonary disease; 2. Patients with acute complications (diabetic ketoacidosis, diabetic ketosis hypertonic coma, diabetes lactic acidosis, etc.); 3. Patients with intolerance to metformin allergy to metformin 4. Patients with history of mental disease, and not suitable for the use of insulin pump; 5. Researchers think that the patients does not fit for this research (such as alcoholism, drug abuse, etc.).