The Impact of Sitagliptin as an Add on Therapy With Closed Loop Control in Adolescents With Diabetic Nephropathy

Inclusion Criteria: * T1DM patients aged 12-18 years with at least 5 years disease duration defined according to the criteria of International Society for Pediatric and Adolescent Diabetes (ISPAD) . * Patients on insulin pump therapy using Medtronic advanced hybrid closed system (Medtronic, Northridge, USA) with Guardian™ 3 sensor or Guardian™ 4 sensor and Guardian link transmitter initiated at least 6 months before the study, patients with minimum daily insulin requirement of more than 8 units, willingness and ability to adhere to the study protocol, and access to the internet as well as a computer system that met requirements for uploading the study pump data. * Active diabetic nephropathy in the form of microalbuminuria (urinary albumin excretion ) 30-299 mg/g creatinine in two of three samples over a 3- to 6-months period despite angiotensin converting enzyme inhibitors). * Hemoglobin A1c (HbA1c) ≤8.5%. * Patients on regular visits to clinic. Exclusion Criteria: * patients with other diabetic microvascular complications (neuropathy or retinopathy) or with macrovascular complications. * Patients with history of liver disease or any disorder likely to impair liver functions or elevated liver enzymes. * Patients with any evidence of renal impairment due to causes other than diabetes. * Patients with hypertension. * Hepatitis virus infection (B or C) or any evidence of infection * Participation in a previous investigational drug study within 3 months preceding screening. *…