Fingolimod for Type 2 Diabetes Mellitus

Inclusion Criteria: 1. Age: 18-70 years old; 2. clinically diagnosed type 2 diabetes. 3. Glycosylated hemoglobin: 6.5% - 9.5%; 4. No drug treatment or only one oral hypoglycemic drug within 6 months; 5. Fasting blood glucose: \< 13.9mmol/l for those without medication, or \< 13.3mmol/l for those with medication; 6. if the antidiabetic drugs are taken, the dosage and the drug must be stable in the past 3 months. 7. Body mass index (BMI) ≤ 45 kg / m2; 8. Sign informed consent Exclusion Criteria: 1. patients with type 1 diabetes; 2. diabetic complications (ketoacidosis, hypertonic state, lactic acidosis). 3. Allergic to the study drug; 4. Abnormal liver and kidney function (transaminase greater than 2.5 times the upper limit of normal value; creatinine greater than 133umol / L); 5. Complicated with other serious organ diseases; 6. Recent disease history (within the past 6 months): myocardial infarction, unstable angina pectoris, stroke, transient ischemic attack, decompensated heart failure requiring hospitalization, or class III / IV heart failure; 7. Presence or history of mobitz type II second or third degree AV block or sick sinus syndrome, unless the patient has a pacemaker; 8. Baseline QT interval extension (male \> 450ms or female \> 460ms); 9. Treatment with class IA or class III antiarrhythmic drugs; 10. Patients with systemic infection (including but not limited to bacteria, fungi, viruses, etc.); 11. Participating in other clinical trials within 3 months; 12. Other circumstances that the investigator considers unsuitable for participating in this clinical study.