The purpose of the study is to examine the effect of Saxagliptin in the newly diagnosed people with pre-diabetes and obesity besides lifestyle intervention ,there to evaluate DPP 4 inhibitors of reversing pre-diabetes curative effect to normal blood sugar, and observe its influences on the targets of obesity related metabolic abnormalities, to explore new ways for intervention on populations with pre-diabetes and obesity .

Materials and Methods: This is a perspectiveness ,randomized, opening study, patients will be randomly assigned to the standarddose Saxagliptin group ,the lifestyle intervention group,the Metformin group and the low dose Saxagliptin group with a 6-month treatment period.

Oral glucose tolerance test will examined before and 6 months post-treatment during the trial.

Inclusion Criteria:

1.Newly diagnosed insulin resistance or glucose intolerance .

2.20 to 70 years of age.

3.BMI≥28kg/m2，or BMI>25kg/m2 beside waistline≥80cm（female)，≥90cm(male).

Exclusion Criteria:

1. Under Diabetes Mellitus treatment.
2. Allergy to dipeptidyl peptidase 4 (DPP-4) inhibitors .
3. Active heart failure.
4. Unwilling or unable to sign inform consents.