Local skin-fold thickness as a clinical predictor of depot size during basal rate infusion of insulin.

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.