Diabetic ketoacidosis due to a sensor defect of FreeStyle Libre: A case report

The FreeStyle Libre Flash Glucose Monitoring System allows users to obtain sensor glucose values by scanning with the reader or their mobile phone. We report a case of a 59-year-old man with type 1 diabetes mellitus who developed diabetic ketoacidosis due to a sensor defect. After replacing the sensor with a new one, the glucose value shown in the device was much lower than usual, which made him consider that he was hypoglycemic. Accordingly, he reduced his insulin dose and eventually developed diabetic ketoacidosis. He was unaware of the discrepancy due to the lack of self-monitoring of his blood glucose, although he was educated to do. In sum, glucose monitoring with the FreeStyle Libre is helpful; however, it is necessary to remind the patient that a sensor defect leading to a severe complication frequently happens.

Automated summary

The FreeStyle Libre Flash Glucose Monitoring System can provide sensor glucose values through scanning. However, this case report highlights the importance of considering sensor defects as they can lead to severe complications like diabetic ketoacidosis. Even though the device showed lower glucose values, the patient mistook it for hypoglycemia and reduced insulin dosage, ultimately leading to diabetic ketoacidosis. It is crucial to remind patients about the potential risk of sensor defects despite the benefits of glucose monitoring with this system.