The purpose of the study is to determine whether in patients with early type 2 diabetes,a short-term intensive metabolic intervention comprising of sitagliptin, metformin, basal insulin glargine and lifestyle approaches will be superior to standard diabetes therapy in achieving sustained diabetes remission.

This is a multicentre, open-label, randomized controlled trial in 100 patients with recently-diagnosed T2DM. Participants will be randomized to 2 treatment groups: (a) a 12-week course of treatment with sitagliptin, metformin, insulin glargine and lifestyle therapy, or (b) standard diabetes therapy, and followed for a total of 64 weeks (1 year and 3 months). In all participants with HbA1C < 7.3% at the 12 week visit, glucose-lowering medications will be discontinued and participants will be encouraged to continue with lifestyle modifications and regular glucose monitoring. Participants with HbA1C ≥ 7.3% at this visit or who meet criteria for hyperglycemic relapse after stopping drugs will receive standard glycemic management as informed by the current Canadian Diabetes Association clinical practice guidelines

Inclusion Criteria:

1. men and women 30-80 years of age inclusive;
2. type 2 diabetes mellitus diagnosed by a physician within 5 years prior to patient enrollment;
3. anti-diabetic drug regimen (either drug or dose of drug) unchanged during 8 weeks prior to screening and randomization;
4. HbA1C ≤ 9.5% on no oral hypoglycemic agents or HbA1C ≤ 8.0% on 1 oral agent or on half-maximal doses of 2 agents;
5. body mass index ≥ 23 kg/m2;
6. a negative pregnancy test and an agreement to use a reliable method of birth control for the duration of the trial in all females with childbearing potential;
7. ability and willingness to perform self-monitoring of capillary blood glucose (SMBG); ability and willingness to self-inject insulin;
8. provision of informed consent.

Exclusion Criteria:

1. current use of insulin;
2. history of hypoglycemia unawareness; history of severe hypoglycemia requiring assistance within the last 5 years;
3. renal dysfunction as evidenced by serum creatinine (Cr) ≥ 124 μmol/l;
4. history of lactic acidosis or diabetic ketoacidosis;
5. active liver disease or elevated alanine transferase (ALT) levels ≥ 2.5 times upper limit of normal at the time of enrollment;
6. history of pancreatitis;
7. cardiovascular disease including any of: a) systolic blood pressure > 180 mmHg or diastolic blood pressure > 105 mmHg; b) peripheral vascular disease; c) left bundle branch block or second or third degree AV block; d) tachyarrhythmias or bradyarrhythmias with uncontrolled ventricular rate; e) stenotic valvular heart disease; f) cardiomyopathy; g) history of heart failure; h) history of aortic dissection; i) documented history of angina or coronary artery disease; j) history of stroke or transient ischemic attack;
8. history of any disease requiring continuous systemic glucocorticoid treatment;
9. history of any major illness with a life expectancy of < 3 years;
10. history of injury or any other condition that significantly limits participant's ability to achieve moderate levels of physical activity;
11. excessive alcohol consumption (>14 alcoholic drinks per week in men and >7 alcoholic drinks per week in women);
12. known hypersensitivity to insulin glargine, metformin, or any DPP-4 inhibitor.

64 weeks