Evaluation of glycemic variation with continuous glucose monitoring in unstable diabetes caused by anti-insulin antibodies

A 76-year-old male was diagnosed to have diabetes mellitus at 57 years of age and oral hypoglycemic agents were started. Aspart, a human insulin analogue, was initiated because of a poor glycemic control in July 2009, at 74 years of age. He complained of dizziness and faintness caused by hypoglycemia in the early morning and afternoon. He was admitted to another hospital in August 2010; his plasma insulin levels were markedly elevated (11,000 μU/ml), and ¹²⁵ I-insulin binding rate of anti-insulin antibodies was 89.5 %. He was transferred to this hospital in September 2010, and a Scatchard analysis of his anti-insulin antibodies showed low affinity and high capacity. The daily profiles of blood glucose were evaluated precisely by continuous glucose monitoring (CGM). CGM showed low blood glucose levels in the early morning and afternoon, when human insulin injections were given twice daily. In addition, insulin and diet therapies were adjusted to prevent hypoglycemia, and accordingly, blood glucose control was improved. Hence, CGM is therefore considered to be useful in the management of brittle diabetes cause by anti-insulin antibodies.