GLP-1Ra Impact on Metabolic Outcomes in Stage 2 T1DM While Receiving Teplizumab

Aims 1-3: Stage 2 T1DM with TZIELD® and GLP-1Ra Inclusion Criteria: * Age: 12-50 years * BMI: 18-31 kg/m2 (adults) or 5-95th %ile (pediatric) * Stage 2 T1DM (i.e., ≥ 2 islet auto-antibodies and: * fasting glucose ≥ 100 mg/dL and \< 126 mg/dL OR * 2-hr OGTT /MMTT ≥ 140 mg/dL and \< 200 mg/dL OR * During an OGTT having a glucose of \> 199 mg/dL at 30, 60, or 90 minutes) Exclusion Criteria: * Comorbidities: * SBP \> 140 mmHg and DBP \> 100 mmHg * eGFR by MDRD equation of \< 60 mL/min/1.73m2 * AST or ALT \> 2.5 times ULN * Family history of medullary thyroid carcinoma * Diagnosis of pancreatitis or gastroparesis within the past 3 years * Medications: Any diabetes medication, any antioxidant vitamin supplement (\<2 weeks before a study), any systemic glucocorticoid, antipsychotic, atenolol, metoprolol, propranolol, niacin, any thiazide diuretic, any OCP with \> 35 mcg ethinyl estradiol, growth hormone, any immunosuppressant, antihypertensive, any antihyperlipidemic * Other: pregnancy, peri- or post-menopausal women, active smoker Aim 4: Early Stage 3 T1DM with GLP-1Ra Monotherapy Inclusion Criteria * Age: 12-50 years * BMI: 18-31 kg/m2 (adults) or 5-95th %ile (pediatric) * Early stage 3 T1DM with either * HbA1c 6.5% to 8.0% at diagnosis OR * HbA1c 5.7% to 6.4% with oral glucose test meeting ADA criteria for stage 3 T1DM within the past three months prior to or during screening visit * Time of stage 3 diagnosis: within eight weeks of first study visit Exclusion Criteria * DKA history: history of diabetic ketoacidosis requiring hospital admission * Comorbidities: * Family history of medullary thyroid carcinoma * Diagnosis of pancreatitis or gastroparesis within the past 3 years * Medications: Any diabetes medication, any antioxidant vitamin supplement (\<2 weeks before a study), any systemic glucocorticoid, antipsychotic, atenolol, metoprolol, propranolol, niacin, any thiazide diuretic, any OCP with \> 35 mcg ethinyl estradiol, growth hormone, any immunosuppressant, antihypertensive, any antihyperlipidemic * Other: pregnancy, peri- or post-menopausal women, active smoker