Abbott has received FDA authorization for Libre Duo, the first 2-in-1 continuous glucose monitoring device that measures glucose and ketone levels simultaneously. The prescription-only sensor is worn for 10 days; by monitoring a type of ketone called beta-hydroxybutyrate in the background, it alerts users when they are approaching dangerous levels. The device uses the same app, works with smartwatches, and allows relatives to track glucose and ketone levels.
Ketone monitoring is particularly important for people at risk of diabetic ketoacidosis (DKA). When there is not enough insulin, the body burns fat to produce energy, forming ketones. Excessively high ketone levels make the blood acidic, leading to DKA, which can progress rapidly and be fatal if left untreated. Although the condition is most common in Type 1 diabetes, it can also occur in Type 2 diabetes. Abbott executive Marc Taub says DKA is the most common hyperglycemic emergency among people with diabetes and one of the leading causes of hospitalization.
According to Dr. David Ahn of Hoag Hospital, the device could be particularly useful for people who use insulin pumps and those taking SGLT2 inhibitors. Pump failures can interrupt insulin delivery and increase the risk of DKA. SGLT2 drugs, meanwhile, can cause ketoacidosis without blood sugar rising significantly, meaning high glucose may not be the traditional warning sign. The limited routine use of ketone strips among adults also increases the potential importance of continuous monitoring.
However, uncertainties remain regarding Libre Duo’s accuracy and how its alerts should be interpreted. Some people with diabetes say they have not needed ketone monitoring for a long time, while others are concerned that false positives could lead to unnecessary and disruptive alerts. Experts note that illness, pregnancy, fasting and intense exercise can temporarily raise ketone levels for reasons other than DKA. Although a threshold of 3 mmol/L has been recommended for ketone levels, it is said to still be the best estimate.
The device could provide more data on ketones and DKA; however, it is emphasized that continuous health data could lead to data fatigue and misinterpretation. The possibility that Libre Duo, which Abbott does not plan to make available over the counter in the short term, could eventually be offered to a broader consumer market and launch a new wave in the field of “metabolic technology” is also being discussed.
Why it matters
Libre Duo’s main distinction is that it combines two biological indicators that are generally assessed separately in diabetes management within the same monitoring process. This could provide additional insight into the risk that may emerge when blood sugar alone does not provide sufficient warning, particularly for people who use insulin pumps and those taking SGLT2 inhibitors. However, the device’s alerts may not be distinguishable from ketones elevated for reasons other than DKA, such as illness, pregnancy, fasting or intense exercise. Therefore, accuracy, the frequency of false positives and how the 3 mmol/L threshold should be used for clinical decisions remain open questions. Continuous data monitoring can also create unnecessary anxiety and data fatigue when it is not interpreted together with healthcare professionals.