Randomized Trial Comparing Sitagliptin to Placebo in Closed Loop

There are many recent advances in insulin treatment of type 1 Diabetes Mellitus (T1DM), however after a meal sugars are always a concern. There is a drug sitagliptin (Januvia) which is FDA approved to treat people with type 2 diabetes which helps correct their glucose (sugars) after meals. This study is going to test whether this drug can improve the after meal sugars in people with type 1 diabetes. To test this, you will be given a mixed meal and its effects on insulin levels. The hormones that affect blood glucose as well as your sugar levels will be measured by a series of blood tests. We will also look for high blood sugars which might occur because of food staying longer in the stomach than usual or due to the suppression of a hormone called glucagon which increases blood sugar. If you qualify, you will be given sitagliptin (Januvia) 50 mg and 100 mg dosages. You and the researchers will not know which dose you are taking at any single visit. We will first enroll 10 subjects with established type 1 Diabetes Mellitus for at least 1 year, between the ages of 18-30 years old. The first 10 patients will be evaluated for safety parameters such as ability to keep blood sugars \< 70 mg/dl for at least 70% of the time, no episode of severe hypoglycemia (low blood sugars) and so on. After this safety criteria is established, we will then recruit subjects between the ages of 14-19 yrs for the next phase of the study. A total of 17 subjects were enrolled into the study.