Abstract
A 72-year-old man was diagnosed with diabetes mellitus and had been treated with oral hypoglycemic agents since he was 45 years of age, and pre-mixed insulin since he was 69 years of age. Although his HbA1c levels were from 8.8-9.8 %, he began to suffer from hypoglycemia in the early morning. It was revealed that his plasma insulin levels and insulin antibody titer were markedly elevated, and that the insulin-binding rate of his insulin antibodies was 95.5 %. A Scatchard analysis of the patient's insulin antibodies showed a high binding capacity and low affinity in high-affinity binding sites. These data suggested that the insulin antibodies observed during insulin therapy induced unstable glycemic control, including hypoglycemia in the early morning. Insulin therapy could not be withdrawn because due to the marked decrease in the patient's endogenous insulin secretion. However, changing the insulin preparations and reducing the frequency of insulin injections improved the glycemic variability and characteristics of the insulin antibodies. We assessed the efficacy of adding liraglutide to the insulin analogue by continuous glucose monitoring (CGM), which was useful for evaluating the patient's daily glucose profiles. In addition, the assessment of the characteristics of the patient's insulin antibodies over a four-year period by the Scatchard analysis was beneficial for maintaining reduced glycemic variability.
