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 ∆ACTH (p = 0.0215) and ∆ cortisol (p = 0.0430) than the XR group. In the BS group, ∆Glu exhibited a significant negative correlation with ∆ACTH and ∆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.
Keywords: Counter regulatory hormones; Dawn phenomenon; Diabetes; Intermittently scanned continuous glucose monitoring; Long-acting insulin.