3. Any current or previous history of endocrine disease, dyslipidemia or malignancy 4. Any significant active (over the past 12 months) disease of the gastrointestinal, pulmonary, neurological, renal (Cr > 1.5 mg/dL) genitourinary, hematological systems, or has severe uncontrolled treated or untreated hyper/ hypotension (sitting diastolic BP > 100 or systolic > 180 or systolic BP<100) or proliferative retinopathy 5. Use of immunosuppressive agents at any time during the study 6. Allergy to any study medication 7. Pregnancy or breastfeeding 8. Heavy smoker 9. Prior nasoduodenal tube insertion under fluoroscopic guidance. 10. Fasting blood glucose > 6.0 mmol/l or known diabetes. 11. Any history of a MI or clinically significant, active, cardiovascular history including a history of arrhythmia's or conduction delays on ECG, unstable angina, or decompensated heart failure.