Short-term intensive insulin therapy (SIIT) is able to reverse β cell dysfunction and induce glycemic remission in patients with newly diagnosed type 2 diabetes. On the other hand, intensive control of glucose and lifestyle modification are two key elements in preventing chronic complications, especially microvascular neuropathy. However, no study reported the long-term effect of SIIT on the chronic complications. In this multi-center, case-control study, effects of SIIT on the proportion of long-term chronic complications as well as potential biomarkers were investigated.

In total, 777 patients with type 2 diabetes, including 259 patients who participated SIIT when diabetes was newly diagnosed and 518 patients who received routine diabetic therapy will be enrolled in 12 centers in China. After baseline assessments, all patients will undergo complications assessment, including records of cardiovascular diseases (CVD), carotid ultrasonography, electrocardiogram, echocardiography, fundus photography, urinary albumin excretion, Toronto Clinical Neuropathy Scale and Composite Autonomic Symptom Score. Primary endpoint is the difference in the proportions of macrovascular and microvascular complications between groups. Secondary endpoints include the difference of glucose control, insulin resistance, complexity of anti-diabetic therapy and self-management skills and quality of life between two groups. What's more, new biomarkers, which may indicate the occurrence of chronic complications of diabetes, such as circulating endothelial progenitor, β cell dysfunction, and T cells.

Inclusion Criteria:

1. Diagnosed as type 2 diabetes for at least 5 years;
2. When diagnosed as diabetes for the first time, aged between 25 and 65 years, body mass index (BMI) 22-35 kg/m2, fasting plasma glucose (FPG) between 7.0 mmol/l (126 mg/dl) and 16.7 mmol/l (300 mg/dl);
3. Short-term intensive insulin therapy group: Patients received short-term intensive insulin therapy for 14 days when newly diagnosed as type 2 diabetes and induce glycemic remission.
4. Routine diabetic therapy group: Patients received routine diabetic therapy as guideline indicated and never induce glycemic remission.

Exclusion Criteria:

1. Type 1 diabetes or special type of diabetes;
2. Acute complications of diabetes (including DKA, HHS and lactic acidosis) when diagnosed as diabetes;
3. Serious microvascular complications: proliferative stage of retinopathy; urine AER >300 mg/g or urine protein positive, quantification >0.5 g/d; uncontrolled painful diabetic neuropathy and significant diabetic autonomic neuropathy when diagnosed as diabetes;
4. Severe macrovascular complications: acute cerebrovascular accident, acute coronary syndrome, vascular intervention for peripheral arterial disease or amputation requiring hospitalization within 12 months prior to enrollment when diagnosed as diabetes;
5. Blood creatinine clearance less than 50 ml/min, alanine aminotransferase ≥2.5×upper limit of normal, total bilirubin ≥1.5×upper limit of normal; Hemoglobin <100 g/L or need regular blood transfusion;
6. Use of drugs that may influence blood glucose within 12 weeks;
7. Systemic infection or serious concomitant disease; patients with malignancy or chronic diarrhea;
8. Uncontrolled endocrine gland dysfunction;
9. Patients with mental or communication disorders;
10. Chronic cardiac insufficiency, heart function class III and above;
11. Pregnant women, lactating women and women of child bearing age who are not willing to take contraception during the study;
12. Subjects who don't cooperate, cannot be followed up or have difficulty in completing the study considered by the investigator.

Patients with type 2 diabetes