Endocrinological evaluation of dawn phenomenon in patients with diabetes and comparison of insulin glargine U-100 biosimilar (Insulin Glargine BS Injection "Lilly") and glargine U-300 (Lantus XR): a randomized controlled study

We investigated the pathophysiology of the dawn phenomenon by examining the effects of changes in blood glucose levels from late night to early morning on various hormones in a group taking glargine BS and a group taking Lantus XR, with the goal of achieving better glycemic control. Patients with types 1 and 2 diabetes scheduled for inpatient education were divided into BS and XR groups. Blood glucose levels were tracked from 0:00 to 7:00, while blood samples were extracted at 3:00 and 7:00 to measure glucose levels and hormones related to the dawn phenomenon. Overall, we analyzed blood sample and intermittently scanned Continuous Glucose Monitoring data of 43 and 40 patients, respectively. From 0:00 to 7:00, the mean blood glucose was significantly lower in the BS group, although the fluctuation was similar (p < 0.0001). The BS group also exhibited significantly higher increment ACTH (p = 0.0215) and increment cortisol (p = 0.0430) than the XR group. In the BS group, increment Glu exhibited a significant negative correlation with increment ACTH and increment cortisol (p = 0.0491). Similar findings were not observed in the XR group. These results suggest that XR may be a better choice for long-acting insulin since it is less likely to induce cortisol secretion. Further, analysis of the dawn phenomenon and non-dawn phenomenon groups showed the mean CPR levels at 3:00 and 7:00 were significantly higher in the latter (p = 0.0135). This supports the conventional belief that appropriate basal insulin replacement therapy is a beneficial treatment for the dawn phenomenon.