Comparison of the effect and safety of metformin and glipizide GITS alone or combination treatment in newly diagnosed non-obese patients with type 2 diabetes

INTERVENTION: Group A:The dose of metformin will be initiated from 500 mg/day at dinner, and further titrated upward in 1500mg/day at 2‐week intervals based on FPG values, to reach the fasting plasma glucose (FPG), assayed in samples obtained by fingerstick, was ?6.1 mmol/l. If the fasting blood glucose dose not achieved the target after the maximal doses, maintain the maximal doses until the completion of the test.;Group B:Glipizide GITS will be initially treated with 5 mg every morning to a dose of 15 mg/day. a.m. at 2‐week intervals until to reach the fasting plasma glucose (FPG), assayed in samples obtained by fingerstick, was ?6.1 mmol/l. If the fasting blood glucose dose not achieved the target after the maximal doses, maintain the maximal doses until the completion of the test.;Group C:Combination of Glipizide GITS and metformin will be initially treated with 5 mg Glipizide GITS every morning and 500 mg/day metformin every dinner, and further titrated metformin upward to 1500mg/day at 1‐week intervals based on FPG values. If the target fasting glucose dose not achieved, then titrate GITS gradually to a maximal dose of 15 mg/day. a.m. at 1‐week interval. If the fasting blood glucose dose not achieved the target after the maximal doses, maintain the maximal doses until the compl; CONDITION: 250.00 Type 2 diabetes/newly diagnosed non‐obese PRIMARY OUTCOME: HbA1c;Achieve HbA1c < 7.0% and HbA1c < 6.5% of the propotion; SECONDARY OUTCOME: fasting proinsulin, proinsulin/insulin ratio;lipid profiles;fasting true insulin and C‐peptide;2h‐postprandial true insulin and C‐peptide during;fasting and 2h‐prandial plasma glucose during standard diet; INCLUSION CRITERIA: 1. Informed consent obtained before any trial‐related activities; 2. Newly diagnosed type 2 diabetic patients had not received anti‐hyperglycaemic therapy; 3. Male or female to be aged from 25 years to 75 years old; 4. FPG levels between 7.0 and 13.0 mmol/l; 5. BMI 18.5 to 28 kg/m2.