Arterial Stiffness in Type I Diabetes Mellitus

Overview

Using radial artery tonometry to study arterial stiffness, the plan is to study a cohort of 65 children with Type I diabetes mellitus. This prospective, crossover study will help determine if there is an acute increase in arterial stiffness in children with Type I diabetes mellitus who do not give extra insulin to cover a meal. This will give more support to show why it is so critical to bolus every time they eat and to bolus on time to decrease cardiovascular consequences of poorly controlled diabetes. The hypothesis is that giving insulin before a meal compared to not giving insulin before a meal will be associated with lower arterial stiffness in children with type I diabetes.

The subject will fast overnight (nothing to eat or drink for at least 8 hours). The subject will be asked to drink a mixed meal replacement drink (Boost) and will be randomized (like flipping a coin) to bolus insulin for the "meal" or to not bolus insulin using their standard insulin dose. Glucose will be monitored with a finger prick before they drink the meal replacement, 1 hour later and finally 2 hours after drinking the meal replacement. Stiffness of the blood vessel of the wrist will be determined using radial tonometry. Radial tonometry is safe and does not hurt. A pen like probe is placed on the blood vessel of the wrist. When the machine reads a good wave form the computer will calculate the stiffness of the blood vessel. This test will be done along with the glucose checks; before drinking the meal replacement drink, and 1 and 2 hours after drinking the meal replacement drink. During the next study visit, the subject will repeat the exact same study described above. However, this time they will receive the other insulin assignment they were assigned during the first study (either bolus or no bolus).

Conditions