24 children (12 African-American, Hispanic, or American Indian, 12 Caucasian) previously diagnosed with type 1 diabetes mellitus will participate in this pilot study to evaluate the presence of hepatic and peripheral insulin resistance. The investigators will use this pilot information to test the hypothesis that insulin resistance occurs in some children with type 1 DM, is secondary to underlying risk factors, and is responsible for increased insulin needs. Methods will include a "step-up" hyperinsulinemic euglycemic clamp and infusion of the stable isotope 6,6-[2H2]-glucose. Patient and parent interviews will be conducted to gather information about nutritional intake, ethnicity, family history, and socioeconomic status. The investigators will also measure inflammatory cytokines and free fatty acids to determine whether they are associated with differences in insulin resistance among type 1 diabetes mellitus patients.