Role of Sympathetic Vasoconstriction on Insulin-Mediated Microvascular Recruitment and Glucose Uptake in Obesity

Inclusion Criteria: * Males and females of all races between 18 and 60 years of age. * Obesity defined as body mass index between 30-40 kg/m2 * Insulin resistance defined as homeostasis model assessment 2 insulin resistance (HOMA2-IR) score \>1.6 (never diagnosed or treated type 2 diabetic), or being a well-controlled type 2 diabetic on metformin only. * Able and willing to provide informed consent Exclusion Criteria: * Pregnancy or breastfeeding * Current smokers or history of heavy smoking (\>2 packs/day) * History of alcohol or drug abuse * Morbid obesity (BMI \> 40 kg/m2) * Previous allergic reaction to study medications * Evidence of type I diabetes. * Cardiovascular disease other than hypertension such as myocardial infarction within 6 months prior to enrollment, presence of angina pectoris, significant arrhythmia, congestive heart failure (LV hypertrophy acceptable), deep vein thrombosis, pulmonary embolism, second or third-degree heart block, mitral valve stenosis, aortic stenosis, or hypertrophic cardiomyopathy * History of serious cerebrovascular disease such as cerebral hemorrhage, stroke, or transient ischemic attack * History or presence of immunological or hematological disorders * Impaired hepatic function \[aspartate amino transaminase (AST) and/or alanine amino transaminase (ALT) \> 2.0 x upper limit of normal range\] * Impaired renal function (serum creatinine \>1.5 mg/dl) * Moderate to severe anemia (hemoglobin \<11 g/dl) * Treatment with serotonin-norep…