Objective— To determine the influence of local adiposity on insulin depot size during CSII at basal rate.
Research Design and Methods— In 27 diabetic patients, a constant infusion of 125I-labeled Actrapid insulin was given, with U-40 insulin at a rate of 1.12 IU/h in 20 patients, and U-100 at a rate of 1 IU/h in 7 patients. After 16 h of infusion, the steady-state depot size was measured by external counting, and the local skin fold was measured with a Harpenden skin-fold caliper.
Results— U-40 insulin infusion resulted in a steady-state depot size of 5.1 U (2.1–10.9 U), and a corresponding skin-fold thickness of 17.8 mm (5–34 mm). A positive correlation was found between depot size and skin-fold thickness. A similar correlation was observed with U-100 insulin.
Conclusions— During basal rate CSII, large variations in local skin-fold thickness create large variations in the steady-state depot size, which is partly predictable just by lifting the skin fold.
