Purpose: Long-term injection of insulin preparations causes subcutaneous amyloid deposits called "insulin balls", leading to impaired blood glucose control due to delayed absorption of the drugs. In order to get therapeutic effects of insulin, proper selection of the injection site is quite essential. Subcutaneous amyloid deposition in abdominal wall can be detected by CT examination. The present study was conducted to establish a method for detection of insulin-derived amyloid deposits and the management of insulin injection site by the combination of continuous blood glucose monitoring (CGM) and abdominal wall CT examination.

Methods: The present study included 120 T2DM patients who were treated with insulin preparations over 5 years. Two weeks CGM was performed using Free Style Libre Pro. In case of significant day-to-day variation in blood glucose control, abdominal wall CT was performed to detect amyloid deposition.

Results: As shown in Figure, abdominal wall CT revealed that subcutaneous amyloid deposition is caused not by ultra-short acting insulin but by long-acting insulin. Blood glucose control was stabilized by insulin injection avoiding amyloid deposits detected by CGM and CT.

Conclusion: CGM and abdominal wall CT examination are useful tools for early detection of amyloid deposition by insulin and optimization of injection site.


A. Hirai: None. K. Hirai: None. H. Nishihara: None. J. Sasaki: None. T. Sudo: None. K. Fujimura: None. T. Kageyama: None.

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