Early Predictors of Brain Health and Development in Youth With T1DM

NewT study staff will work with inpatient diabetes nurses and clinical diabetes educators at St. Louis Children's Hospital to identify patients that are admitted for new onset T1DM. Once the patients are clinically stable, the diabetes educator will visit the patient in the inpatient room and invite the family to participate in the study. If study participants would like to be enrolled, consent and assent will be obtained at that time. If potential participants are unsure at that time, the diabetes educator will provide the family with a blank copy of the consent form to be reviewed. Study information as well as contact information for study staff so that the family may contact the study should the family have additional questions or choose to enroll in the study. Following is a description of the testing days.

Mixed Meal Tolerance Tests (MMTTs) Once the patient has been consented to participate in the study, in the T1DM group, a Mixed-Meal Tolerance Tests (MMTT) will be administered at both study visits (3 mo & 21 mo post diagnosis). If participants are in the control group, the MMTT will only be administered at the 21 mo visit (18 months after the initial visit). For the MMTT, the T1DM group will be instructed to consume at least 150 g of carbohydrates per day for 3 days prior to the MMTT and to consume only water after midnight on the night prior to testing. If the patient is on insulin injection therapy the study nurse will ask the patient to administer the usual basal insulin dose(s) on the night before or on the morning of the study but to hold the morning dose of short- and intermediate-acting insulin. If the patient is on a continuous subcutaneous insulin pump infusions will remain on the usual basal rates for the duration of the study. For the MMTT a small needle, will be placed to collect blood samples. While there are multiple collection times, there is only one stick. The study nurse will then ask participants to drink a Boost High Protein Nutritional Energy Drink. Blood samples will then be obtained at the following time points: -10, 0, 15, 30, 60, 90, 120, 150, 180, 210, and 240 min. This amounts to approximately 4.5 tablespoons of blood. To clarify, only the T1DM group will have the MMTT at the first study visit (3 mo after T1DM dx), both the T1DM and the Control groups will have MMTT at the 21 month visit.

Cognitive Testing The cognitive testing or thinking tests, consist of memory tests, computer games and vocabulary tests. These tests will be administered by a trained staff member and will take approximately 60 minutes to complete. Some of the tests are: a Picture Vocabulary Test, a Picture Sequence Memory Test; an Inhibitory Control and Attention Test; a Dimensional Change Card Sort Test, and a List Sorting Working Memory Test.

Before and after the cognitive testing, blood glucose levels will be determined (using a finger prick) for participants in both groups. Participants with blood glucose values below 70 mg/dl or above 300 mg/dl will be treated and re-tested before testing resumes.

At some point during the study, one parent from each family will be requested to perform a brief reading test that provides an estimated intelligence quotient (IQ). This test takes approximately 10 minutes.