Tissue IGF-I Measured by Microdialysis Reflects Body Glucose Utilization After rhIGF-I Injection in Type 1 Diabetes.

Context: Type 1 diabetes is associated with portal insulin deficiency and disturbances in the GH-IGF axis including low circulating IGF-I and GH hypersecretion. Whether peripheral hyperinsulinemia and GH hypersecretion, which are relevant to the development of vascular complications, result in elevated tissue IGF-I remains unknown. Objective: The purpose of this study was to determine the relationship between whole-body glucose uptake and tissue IGF-I measured by microdialysis. Design: This was a single-blind placebo-controlled crossover study. Setting: The setting was a tertiary pediatric endocrine referral center. Participants: The participants were seven young male adults with type 1 diabetes. Intervention: After an overnight fast, a 6-h lasting euglycemic clamp was performed (constant insulin infusion at 0.5 mU/kg × minute and variable glucose infusion rate [GIR]) and a subcutaneous injection of recombinant human (rh) IGF-I (120 μg/kg) or saline was given after 2 hours. In parallel, tissue IGF-I level...