2023 Volume 72 Issue 3 Pages 434-439
The dawn phenomenon is an increase in insulin antagonist hormone secretion during the night, which causes an increase in blood glucose levels at dawn. It causes hyperglycemia in type 1 diabetics with reduced endogenous insulin secretion. If blood glucose control is unstable owing to the dawn phenomenon, management by CSII is recommended. In the present case, we experienced treating a patient who was on SAP therapy to reduce the effects of the dawn phenomenon and switched to HCL therapy. The patient, a woman in her 60s, had poor blood glucose control on MDI due to the dawn phenomenon, so SAP therapy was initiated. Later, on HCL therapy, the HbA1c level was 6.9 to 7.1%, and good blood glucose control was achieved with TIR above 70%, TBR below 4%, and TAR below 25%. However, the dawn phenomenon caused an increase in blood glucose levels from 4 to 7 am. Therefore, in addition to auto basal insulin infusion with HCL therapy, 0.5 units of insulin was infused to cope with the hyperglycemia caused by the dawn phenomenon. Compared with SAP therapy, pre-breakfast blood glucose levels were significantly elevated with HCL therapy alone but were comparable after the response. We experienced treating a patient in whom the auto-basic insulin infusion algorithm failed to respond to predictable changes such as the dawn phenomenon. The time of day when insulin infusion is insufficient should be determined by the user and managed accordingly.
