Abstract Body

Current methods of ketone measurement using urine or blood ketones do not indicate the onset of ketosis or ketoacidosis, rather confirm if it is already in progress. In the case of diabetes ketoacidosis (DKA), alerting the patient about an impending DKA would reduce the complications of DKA, including hospitalization or even prevent it.
Feasibility of a subcutaneous continuous ketone monitoring (CKM) sensor was demonstrated using β-hydroxybutyrate dehydrogenase enzyme with a proprietary mediation chemistry in a FreeStyle Libre 2 sensor form factor. The in vitro performance of the sensor has been demonstrated up to 8 mmol/L, showing that the sensor responds linearly to the change in the concentration of ketone and with minimal variation between sensors. The first human study with participants on low carbohydrate diet demonstrated that subcutaneous ketone can be measured with these sensors, which tracks the capillary ketone levels over a 14-day period with a single retrospective calibration. The ketone levels generated with low carbohydrate diet were limited to 2mmol/L.
For the CKM sensor to be viable, the sensor needs factory calibration, as the fingerstick calibration is impractical. Performance of a factory calibrated sensor in the FreeStyle Libre 2 form factor was evaluated in a clinical setting where the study participants (without diabetes) consumed exogenous ketone to generate elevated ketone levels. The sensor results were compared to venous blood ketone using Precision Xtra ketone test strips. The sensor responded quicky to the changing ketone concentrations and the lag time was about 4 minutes. The mean absolute difference between the sensor and the reference results was 0.3 mmol/L.
The integrated continuous glucose – ketone monitoring will leverage the FreeStyle Libre 3 form factor. This dual analyte sensor system is designed to continuously monitor glucose and ketones levels every minute, in one sensor.
Funding: This study was funded by Abbott Diabetes Care, Alameda, CA

Abstract Body

Current methods of ketone measurement using urine or blood ketones do not indicate the onset of ketosis or ketoacidosis, rather confirm if it is already in progress. In the case of diabetes ketoacidosis (DKA), alerting the patient about an impending DKA would reduce the complications of DKA, including hospitalization or even prevent it.
Feasibility of a subcutaneous continuous ketone monitoring (CKM) sensor was demonstrated using β-hydroxybutyrate dehydrogenase enzyme with a proprietary mediation chemistry in a FreeStyle Libre 2 sensor form factor. The in vitro performance of the sensor has been demonstrated up to 8 mmol/L, showing that the sensor responds linearly to the change in the concentration of ketone and with minimal variation between sensors. The first human study with participants on low carbohydrate diet demonstrated that subcutaneous ketone can be measured with these sensors, which tracks the capillary ketone levels over a 14-day period with a single retrospective calibration. The ketone levels generated with low carbohydrate diet were limited to 2mmol/L.
For the CKM sensor to be viable, the sensor needs factory calibration, as the fingerstick calibration is impractical. Performance of a factory calibrated sensor in the FreeStyle Libre 2 form factor was evaluated in a clinical setting where the study participants (without diabetes) consumed exogenous ketone to generate elevated ketone levels. The sensor results were compared to venous blood ketone using Precision Xtra ketone test strips. The sensor responded quicky to the changing ketone concentrations and the lag time was about 4 minutes. The mean absolute difference between the sensor and the reference results was 0.3 mmol/L.
The integrated continuous glucose – ketone monitoring will leverage the FreeStyle Libre 3 form factor. This dual analyte sensor system is designed to continuously monitor glucose and ketones levels every minute, in one sensor.
Funding: This study was funded by Abbott Diabetes Care, Alameda, CA