Skinfold thickness, local subcutaneous blood flow and insulin absorption in diabetic patients

The influence of skinfold thickness on the local subcutaneous blood flow (SBF) and absorption rate of subcutaneously injected and infused soluble insulin was investigated in insulin-dependent diabetic patients. The local 133Xenon washout technique was used for measuring SBF and the disappearance of 125I labelled insulin for measuring insulin absorption. A Harpenden skinfold caliper was used for measuring skinfold thickness. A large variation in skinfold thickness (range 6-40 mm, N = 50) was demonstrated. The SBF was curvilinear related to the skinfold thickness with decreasing SBF for increasing skinfold thickness (N = 50). A similar relationship was found between the SBF and the absorption rate of subcutaneously injected (N = 10) and infused (N = 7) insulin. The large variation in skinfold thickness and thus insulin absorption may partly explain the well-known large inter-individual variation in insulin absorption, and the different absorption rates from areas with different skinfold thickness should be taken into account when treating with insulin.