Cardiometabolic Benefit of Reducing Iatrogenic Hyperinsulinemia Using Insulin Adjunctive Therapy in Type 1 Diabetes

Inclusion Criteria: Age: 18-60 years BMI: 18-28 kg/m² Weight: ≥ 50 kg T1DM Participants: Duration of T1DM: 1-30 years HbA1c: 5.7-7.5% Insulin Therapy: Using automated insulin delivery GCK-MODY Participants: HbA1c: 5.7-7.5% Genetic Confirmation: Positive GCK sequencing Control Participants: HbA1c: less than 5.5% \*\* Exclusion Criteria: Severe Hypoglycemia: ≥1 episode in the past 3 months Comorbidities: * Any hospital admissions for diabetic ketoacidosis in the past 6 months * SBP greater than 140 mmHg and DBP greater than 100 mmHg * eGFR by MDRD equation of less than 60 mL/min/1.73 m² * AST or ALT greater than 2.5 times ULN * Hct less than 35% Medications: * Any antioxidant vitamin supplement within 2 weeks before the study * Any systemic glucocorticoid * Antipsychotics * Atenolol, Metoprolol, Propranolol * Niacin * Any thiazide diuretic * Any oral contraceptive pill with greater than 35 mcg ethinyl estradiol * Growth hormone * Any immunosuppressant * Antihypertensive * Any antihyperlipidemic Other: * Pregnancy * Tanner stage less than 5 * Peri- or post-menopausal women * Active smoker T1DM Participants: Medications: Any diabetes medication except insulin C-peptide: greater than 0.7 ng/mL (fasting) GCK-MODY Participants: None specific