Inclusion criteria  Inclusion criteria (Aim 1):  Men and women between the ages of 45 and 80 years undergoing non-cardiac general or vascular surgery BMI ≥30 kg/m2 without a previously known history of DM  Inclusion criteria (Aim 2):  Men and women without known history of diabetes with ages between 45 and 80 years undergoing non-cardiac general or vascular surgery participating in Aim 1. BMI ≥30 kg/m2 and pre-DM or DM by OGTT or HbA1c.  Exclusion Criteria:  Exclusion criteria (Aim 1):  Patients prescribed or taking antihyperglycemic medications Patients undergoing cardiac surgery or patients anticipated to require ICU care Patients expected to be admitted less than 48-72 hours after surgery Severely impaired renal function (eGFR < 30 mL/min) or clinically significant hepatic failure Treatment with oral (equivalent to prednisone > 5 mg/day) or injectable corticosteroids Mental condition rendering the subject unable to understand the nature, scope, and possible consequences of the study; unable to consent Pregnant or breast feeding at time of enrollment Prisoners  Exclusion criteria (Aim 2):  Same as in Aim 1, with the following additional exclusion criteria: Patients undergoing gastrointestinal surgery or at high risk for gastrointestinal obstruction/ileus or expected to require gastrointestinal suction Patients with delayed gastric emptying, pancreatic or gallbladder disease Patients with personal or family history of medullary thyroid cancer or multiple endocrine neoplasia syndrome type 2 (MEN2)