Distinct hypoglycemic effect of different formulations of a fixed ratio of basal insulin plus glucagon-like peptide-1 receptor agonist in a patient with pancreatic diabetes.

Fixed-ratio combination injection therapy (FRC) is a fixed-ratio mixture containing basal insulin and glucagon-like peptide-1 receptor agonist (GLP-1 RA) in a single injection for the treatment of patients with type 2 diabetes. The two types of FRC products contain different concentrations and mixing ratios of basal insulin and GLP-1 RA. Both products demonstrated satisfactory blood glucose control throughout the day, with less hypoglycemia and weight gain. However, few studies have examined the differences in the actions of the two formulations. Herein, we present a case of a 71-year-old man with pancreatic diabetes and significantly impaired intrinsic insulin secretion capacity, who demonstrated a marked difference in glycemic control following treatment with two different FRC formulations. Treatment with IDegLira, an FRC product, demonstrated suboptimal glucose control in the patient. However, after a change in therapy to another FRC product, IGlarLixi, his glucose control markedly improved, even with a decrease in the injection dose. This difference could have been due to lixisenatide, a short-acting GLP-1RA contained in IGlarLixi, which exerts a postprandial hypoglycemic effect irrespective of intrinsic insulin secretion capacity. In conclusion, IGlarLixi has the potential to achieve good fasting and postprandial glucose control with a once-daily injection, even in patients with type 2 diabetes who have a reduced intrinsic insulin secretion capacity. Supplementary Information: The online version contains supplementary material available at 10.1007/s13340-023-00621-5.