The Impact of Bariatric Surgery on Adipocyte Metabolism

Obese Subjects Inclusion Criteria: * 18-55 years old * Female * BMI greater than 40 kg/m2 * Scheduled for bariatric surgery at the Center for the Surgical Treatment of Obesity at the University of Chicago * Signed informed consent Exclusion Criteria: * Male * Diagnosed with a systemic illnesses, including heart, renal, liver, or malignant disease * Uncontrolled hypertension (blood pressure greater than 140 mmHg systolic and 90 mmHg diastolic without medication) * use of beta blockers * hemoglobin less than 11.5g/dL * known allergy to lidocaine * pregnancy * lactation * Subjects will not have undergone surgery, donated a unit of blood, or participated in another clinical study within the last 4 weeks prior to consent. * Post-menopausal Non-Obese Subjects Inclusion Criteria: * 18-55 years old * Female * BMI less than 30 kg/m2 * Signed informed consent Exclusion Criteria: * Male * Diagnosed with a systemic illnesses, including heart, renal, liver, or malignant disease * Uncontrolled hypertension (blood pressure greater than 140 mmHg systolic and 90 mmHg diastolic without medication) * use of beta blockers * hemoglobin less than 11.5g/dL * known allergy to lidocaine * pregnancy * lactation * Subjects will not have undergone surgery, donated a unit of blood, or participated in another clinical study within the last 4 weeks prior to consent. * Post-menopausal