Continuous Glucose Monitoring and Hypoglycemia Unawareness in Type 1 Diabetes

To confirm hypoglycemia unawareness, patients answered a questionnaire based on the items explored by the model of Clarke 19 about hypoglycemia and hypoglycemia awareness. The eligibility of patients was confirmed by a blinded CG M recording using the trademark iPro ™ 2 sensor for 6 days. During this period the patient reported on a logbook the perception of their hypoglycemia, symptoms and how any hypoglycemia was corrected. Hypoglycemic manifestations were divided into adrenergic (shakiness, anxiety, palpitations, sweating, hunger, nausea, headache, coldness and pallor) and neuroglycopenic effects (impaired judgment, moodiness, paresthesia, emotional lability, confusion, ataxia, double vision, amnesia, seizures and lethargy). The confrontation of hypoglycemia detected by the blinded CG M and self-reported hypoglycemia validated the diagnosis of hypoglycemia unawareness.

Patients used the Paradigm® Veo™ pump and glucose sensors (trademark : Enlite®) with an hypoglycemia alarm set at sensor glucose value of 70 mg/dL while the LG S option was set to suspend insulin delivery at a sensor glucose value of 50 mg/dL or less. These thresholds allowed an active correction of hypoglycemia by the patient between 50 and 70 mg/dL. Patients were educated to use the system and to treat and manage hypoglycemia. Pump data were uploaded using the trademark Medtronic CareLink™ Management Software for Diabetes during visits at 10 days (D10), 2 months (M2) and 3 months (M3). Hypoglycemia awareness was assessed by an initial quiz that was repeated at M3 and 6 months (M6). A blinded CGM iPro ™ 2 was also realized at M3 to validate the modifications after sensor-augmented insulin-pump therapy.

Inclusion criteria

• >18 years
• type 1 diabetes
• had been treated with insulin pump for more than three months
• had hypoglycemia unawareness with a hypoglycemia perception threshold below 60 mg/dL and/or had had at least one severe hypoglycemia event in the previous year

Exclusion criteria

• > 18 years
• any serious disease that could interfere with the study
• pregnancy,
• incompatibility with monitoring,
• irregular management of diabetes,
• hearing loss and low vision,
• preventing them from using the devices