Terumasa Nagase1, Keiichi Iwaya2, Yoshiki Iwaki3, Fumio Kotake4, Ryuji Uchida5, Tsunao Oh-i6, Hidenori Sekine3, Kazuhiro Miwa3, Satoshi Murakami3, Tomotada Odaka3, Masahiko Kure3, Yoko Nemoto3, Masayuki Noritake3, Yoshiya Katsura3. 1. Department of Metabolism and Endocrinology, Tokyo Medical University Ibaraki Medical Center, Ami, Ibaraki, Japan. Electronic address: tnagase@tokyo-med.ac.jp. 2. Department of Pathology, National Defense Medical College, Tokorozawa, Saitama, Japan. 3. Department of Metabolism and Endocrinology, Tokyo Medical University Ibaraki Medical Center, Ami, Ibaraki, Japan. 4. Department of Radiology, Tokyo Medical University Ibaraki Medical Center, Ami, Ibaraki, Japan. 5. Department of Plastic Surgery, Tokyo Medical University Ibaraki Medical Center, Ami, Ibaraki, Japan. 6. Department of Dermatology, Tokyo Medical University Ibaraki Medical Center, Ami, Ibaraki, Japan.
Abstract
OBJECTIVES: Insulin-derived amyloidosis is a rare skin-related complication of insulin therapy. The purpose of this study was to show the effects of insulin-derived amyloidosis on blood glucose levels, insulin dose requirements, and insulin absorption. METHODS: Seven patients were found to have insulin-derived amyloidosis at the Tokyo Medical University Ibaraki Medical Center. The clinical characteristics and insulin therapy of the 7 patients were investigated. Insulin absorption was studied by comparing the serum insulin levels after insulin injections into insulin-derived amyloidosis sites versus injections into normal sites in 4 patients. RESULTS: When the insulin-derived amyloidosis was discovered, the mean hemoglobin A1c level was 9.3%, and the mean daily insulin dose was 57 units. After changing the injection sites to avoid the insulin-derived amyloidosis, the blood glucose concentrations improved, and the mean daily insulin dose could be reduced to 27 units (P = .035; 53% reduction). The insulin absorption at insulin-derived amyloidosis sites was 34% of that at normal sites (P = .030). CONCLUSIONS: Insulin-derived amyloidosis caused poor glycemic control and increased insulin dose requirements because of impairments in insulin absorption.
OBJECTIVES:Insulin-derived amyloidosis is a rare skin-related complication of insulin therapy. The purpose of this study was to show the effects of insulin-derived amyloidosis on blood glucose levels, insulin dose requirements, and insulin absorption. METHODS: Seven patients were found to have insulin-derived amyloidosis at the Tokyo Medical University Ibaraki Medical Center. The clinical characteristics and insulin therapy of the 7 patients were investigated. Insulin absorption was studied by comparing the serum insulin levels after insulin injections into insulin-derived amyloidosis sites versus injections into normal sites in 4 patients. RESULTS: When the insulin-derived amyloidosis was discovered, the mean hemoglobin A1c level was 9.3%, and the mean daily insulin dose was 57 units. After changing the injection sites to avoid the insulin-derived amyloidosis, the blood glucose concentrations improved, and the mean daily insulin dose could be reduced to 27 units (P = .035; 53% reduction). The insulin absorption at insulin-derived amyloidosis sites was 34% of that at normal sites (P = .030). CONCLUSIONS:Insulin-derived amyloidosis caused poor glycemic control and increased insulin dose requirements because of impairments in insulin absorption.