Evaluation of Cardiac Sympathetic Nervous Function by 123I-Metaiodobenzylguanidine Scintigraphy in Insulin-Treated Non-Insulin Dependent Diabetics with Hypoglycemia Unawareness

• Published in: Internal Medicine Vol. 35; no. 2; pp. 94 - 99
• Main Authors: OHNO, Tomio, TOYAMA, Takuji, HOSHIZAKI, Hiroshi, OKAMOTO, Eiichi, NAITO, Shigeto, NOGAMI, Akihiko, KAMIYAMA, Hiroshi, OHSHIMA, Shigeru, YUASA, Kazuo, TANIGUCHI, Koichi, TOMONO, Shoichi, KAWAZU, Shoji
• Format: Journal Article
• Language: English
• Published: Japan The Japanese Society of Internal Medicine 1996
• Subjects: 3-Iodobenzylguanidine; autonomic neuropathy; catecholamine; Diabetes Mellitus, Type 2 - blood; Diabetes Mellitus, Type 2 - drug therapy; Diabetes Mellitus, Type 2 - physiopathology; Epinephrine - blood; Heart - diagnostic imaging; Heart - innervation; Heart Function Tests; Humans; Hypoglycemia - blood; Hypoglycemia - chemically induced; Hypoglycemia - physiopathology; Hypoglycemic Agents - adverse effects; Hypoglycemic Agents - therapeutic use; Injections, Intravenous; Insulin - adverse effects; Insulin - therapeutic use; insulin-induced hypoglycemia; Iodine Radioisotopes; Iodobenzenes; Middle Aged; myocardial scintigraphy; Norepinephrine - blood; Perception; Radionuclide Imaging; Sympathetic Nervous System - diagnostic imaging; Sympathetic Nervous System - physiopathology; Sympatholytics
• ISSN: 0918-2918; 1349-7235
• DOI: 10.2169/internalmedicine.35.94

The association between the lack of adrenergic symptoms during hypoglycemia and myocardial 123I-metaiodobenzylguanidine (MIBG) accumulation was investigated in 12 insulin-treated non-insulin-dependent diabetes mellitus (NIDDM) patients who had no evidence of heart disease. These patients were divided into 2 groups according to the presence (group A) or absence (group B) of adrenergic symptoms during hypoglycemia. Autonomic function tests revealed significantly severe autonomic dysfunction in group B compared to that in group A. Insulin infusion test indicated no significant difference in the catecholamine response between the two groups. 123I-MIBG scintigraphy showed that the heart/mediastinum ratio of MIBG uptake was significantly lower, and scintigraphic defect was greater in group B than in group A. There were no significant differences in the washout rate between the two groups. These results suggested that the lack of adrenergic symptoms during hypoglycemia may be associated with cardiac sympathetic nervous dysfunction in insulin-treated NIDDM patients, and this dysfunction is mainly due to cardiac sympathetic denervation. (Internal Medicine 35: 94-99, 1996)