The Effects of Glucagon on Hepatic Metabolism

Inclusion Criteria - Obese Subjects with Type 2 Diabetes: * Type 2 diabetes * BMI ≥ 28 Kg/M2 * Managed by diet alone or a combination of metformin and/or sulfonylurea * Willing to stop glucose-lowering medication for 3 weeks prior to participation and willing to self-monitor their fasting glucose during this time * No history of micro- or macrovascular complications of T2DM Exclusion Criteria - Obese Subjects with Type 2 Diabetes: * Age \< 25 or \> 65 years * HbA1c ≥ 8.5% * BMI ≤ 28 Kg/M2 * For female subjects: positive pregnancy test at the time of enrollment or study * History of prior upper abdominal surgery such as adjustable gastric banding, pyloroplasty and vagotomy. * Active systemic illness or malignancy. * Symptomatic macrovascular or microvascular disease. * Known contraindications to MRI * Hematocrit \< 35% * History of uncontrolled thyroid disease * Consumption of \> 2 alcohol drinks per day or \> 14 per week or a positive AUDIT questionnaire. * Allergy to iodine * Thrombocytopenia, history of bleeding disorder or use of anticoagulation * Subjects with treatment change or significant weight change (≥ 10%) in the prior 3 months. Inclusion Criteria - Obese subjects without Type 2 Diabetes: -Obese subjects without type 2 diabetes but are age, sex and weight-matched (BMI ≥ 28 Kg/M2) with subjects who have T2DM Exclusion Criteria - Obese Subjects without Type 2 Diabetes: * Age \< 25 or \> 65 years (match subjects with T2DM) * HbA1c ≥ 6.5% * BMI ≤ 28 Kg/M2 * Use of any glucose-lowering agents * For female subjects: positive pregnancy test at the time of enrollment or study * History of prior upper abdominal surgery such as adjustable gastric banding, pyloroplasty and vagotomy. * Active systemic illness or malignancy. * Symptomatic macrovascular or microvascular disease. * Known contraindications to MRI * Hematocrit \< 35% * History of uncontrolled thyroid disease. * Consumption of \> 2 alcohol drinks per day or \> 14 per week or a positive AUDIT questionnaire. * Allergy to iodine * Thrombocytopenia, history of bleeding disorder or use of anticoagulation Inclusion Criteria - Lean subjects without Diabetes: -Subjects who do not have type 2 diabetes but are age and sex but are not weight-matched (BMI ≤ 25 Kg/M2) with subjects who have T2DM Exclusion Criteria - Lean subjects without Diabetes: * Age \< 25 or \> 65 years (match subjects with T2DM) * HbA1c ≥ 6.5% * BMI ≥ 25 Kg/M2 unless % body fat is \< 20% in males and \< 30% in females. * Use of any glucose-lowering agents * For female subjects: positive pregnancy test at the time of enrollment or study * History of prior upper abdominal surgery such as adjustable gastric banding, pyloroplasty and vagotomy. * Active systemic illness or malignancy. * Symptomatic macrovascular or microvascular disease. * Known contraindications to MRI * Hematocrit \< 35% * History of uncontrolled thyroid disease. * Consumption of \> 2 alcohol drinks per day or \> 14 per week or a positive AUDIT questionnaire. * Liver fat content ≥ 5% as determined by MRI using the proton density fat fraction (PDFF) technique. * Allergy to iodine * Thrombocytopenia, history of bleeding disorder or use of anticoagulation