Inclusion Criteria:  Youth with pancreatic antibody positive type 1 diabetes Age 12-21 years Use of an automated insulin delivery system or multiple daily insulin injections plus a continuous glucose monitor for > 6 months Pubertal Weight > 54 kg and BMI > 5th percentile for age and sex Hemoglobin A1c < 11% No recent episodes of diabetic ketoacidosis (DKA) or hyperglycemic hyperosmolar syndrome (HHS)  Exclusion Criteria:  Blood pressure > 140/90 mm Hg Anemia Estimated glomerular filtration rate < 60 mL/min/1.73 m2 or serum creatinine > 1.2 mg/dL or history of urinary albumin to creatinine ratio ≥ 300mg/g or history of acute kidney injury Use of anti-diabetic agents except insulin, angiotensin converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARB's), diuretics, daily non-steroidal anti-inflammatory drugs (NSAIDs) or aspirin, sulfonamides, procaine, thiazosulfone or probenecid Seafood or iodine allergy Pregnancy or breast feeding for females