FDA clears first wearable to track ketones and blood sugar in real time

The U.S. Food and Drug Administration (FDA) has authorised the Libre Duo 10 Day Continuous Dual Glucose Ketone Monitoring System, a wearable device designed for individuals aged two years and older living with diabetes. The authorisation, granted to Abbott Diabetes Care, represents a significant milestone in medical technology, as the device is the first in the United States to continuously monitor ketone levels. It is also the first device globally capable of tracking both ketones and blood sugar, or glucose, simultaneously within a single unit.

The system functions by measuring ketone and glucose levels in the fluid just beneath the skin, known as subcutaneous fluid, every minute, day and night. These readings are transmitted wirelessly to a compatible smartphone, allowing users to view current levels and observe whether they are trending up or down. The device is equipped to send automatic alerts if ketone levels reach a concerning threshold, a feature intended to help patients and caregivers identify rising ketones before they develop into a medical emergency.

Diabetic ketoacidosis, or DKA, is a serious and potentially life-threatening complication that occurs when the body produces excessive ketones. This condition can develop rapidly if left untreated. Until now, monitoring ketones required separate tests that provided only single-point measurements, unable to indicate whether levels were rising or falling. The continuous nature of the new device addresses this gap by providing real-time data that can facilitate early intervention.

The FDA’s decision follows a comprehensive review of clinical and performance data submitted by the device sponsor. The clinical program included six studies that enrolled more than 600 participants aged two years and older to evaluate the accuracy of the device’s monitoring functionality. The results demonstrated that the device accurately tracked clinically meaningful differences in ketone levels across its 10-day wear period, including identifying elevated ketone levels before the onset of DKA.

Prior to authorisation, the FDA granted Breakthrough Device designation to the system, a status intended to expedite the development and review of devices that offer more effective treatment or diagnosis for life-threatening conditions. The marketing authorisation was granted through the De Novo premarket review pathway, a regulatory route for low- to moderate-risk devices of a new type. Along with this authorisation, the FDA is establishing special controls that define requirements related to labelling and performance testing to ensure safety and effectiveness.

Michelle Tarver, M.D., Ph.D., Director of the FDA’s Center for Devices and Radiological Health, described the authorisation as a breakthrough for the safety of children and adults living with diabetes. She noted that having real-time information on rising ketone levels, around the clock, can be the difference between early intervention and a life-threatening emergency. The authorisation also aligns with the FDA’s Home as a Health Care Hub Initiative, which aims to advance patient-centred devices that integrate seamlessly into daily life at home.