Quantitative Evaluation of Insulin Injection-induced Abdominal Subcutaneous Dystrophic Tissue Using Shear Wave Elastography

Subcutaneous dystrophic tissue produced by injection of insulin causes dysglycemia due to inadequate absorption of insulin. However, precise techniques to measure the dystrophic tissue have not been established. Shear wave elastography (SWE) is an imaging technology that can quantify tissue stiffness. We evaluated insulin injection-induced dystrophic tissue by SWE. We recruited seven patients with type 2 diabetes who had suspicion of the abdominal dystrophic tissue. Using SWE, we measured the shear wave velocity (SWV) of the dystrophic tissue and the normal adipose tissue as a control. Furthermore, two patients underwent whole abdominal SWE examination and we calculated the proportion of dystrophic tissue. We also performed a subcutaneous insulin tolerance test at both dystrophic tissue and control sites. The mean SWV of the dystrophic tissue was significantly higher than the control (2.87 ± 0.24 vs. 1.34 ± 0.11 m/s, p<0.01). The volume of the dystrophic tissue was 2.94 ± 3.21%. The mean area under the curve of subcutaneous injected Insulin Aspart concentration at the dystrophic tissue sites was lower than control (80.3 ± 31.4 vs. 119 ± 34.2 h*mU/L, p=0.10). The results from this study indicate that SWE can be useful in evaluating abdominal subcutaneous dystrophic tissue.