1) poorly controlled hypertension: >160 mmHg systolic blood pressure and/or>100 mmHg diastolic blood pressure (with or without long-term oral antihypertensive drugs); 2) Chronic heart failure NYHA class (III-IV); 3) An acute coronary or cerebro-vascular event within the previous 6 months; 4) hematological malignancies such as acute or chronic myeloid leukemia, or any other hematological disorders that would interfere with the determination of circulating EPC levels; 5) Personal history of non-familial medullary thyroid carcinoma; 6) Immunological disorders such as lupus, psoriasis, scleroderma and rheumatoid arthritis which would interfere with the determination of circulating EPC levels; 7) Chronic haemodialysis or chronic peritoneal dialysis; 8) End stage liver disease, presence of acute or chronic liver disease or recent history of the following: ALT level ≥ 3 times the upper limit of normal, or AST level ≥ 3 times the upper limit of normal; 9) Severe gastrointestinal diseases, such as gastrointestinal ulcer, gastrointestinal bleeding, pyloric stenosis, gastric bypass surgery; 10) History of chronic pancreatitis or idiopathic acute pancreatitis; 11) Any acute condition or exacerbation of chronic condition that would in the Investigator's opinion interfere with the initial trial visit schedule and procedures; 12) Inability to walk on a tredamill without grade at a speed of at least 3.2 km/h for at least 2 minutes.