Data from a team of Dutch researchers presented this weekend at the Endocrinology Society’s annual meeting in Chicago demonstrated how vital monitoring wearables could identify Type 1 diabetes patients’ hypoglycemic events by measuring heart rate.

The pilot study outfitted 27 adult patients with VitalConnect’s HealthPatch MD, a continuous health monitor that the company has since replaced with the disposable, peel-and-stick VitalPatch. With these, the researchers aimed to explore a faster monitor-driven approach to low blood sugar detection than simply relying on CGMs, which often have a delay.

"This delay can compromise the accuracy of measuring low glucose values,” Dr. Marleen Olde Bekkink, an endocrinology fellow at Radboud University Medical Center in Nijmegen, Netherlands, and the study’s principal investigator, said in a statement. "People with impaired awareness of hypoglycemia may need to wear an additional monitor.”

Participating Type 1 diabetes patients wore VitalConnect’s monitors on their chest for five consecutive days, with hypoglycemic events verified by an accompanying CGM or by the patients themselves via fingerstick measurement. Heart rate data from VitalConnect monitors was transmitted wirelessly to an Apple device, and was then fed into an algorithm developed by the team that aimed to equate heart rate variability with a hypoglycemic event.

The researchers included 20 patients in the final analysis, among whom 10 experienced a total of 39 hypoglycemic events. Of these events, the wearables detected 20 increases in low and high frequency ratio and 18 decreases in successive R-R intervals (heart period variability), both of which led to a hypoglycemic episode in the patients. These patterns led to 28 events that could be identified early using the heart monitors, while 11 displayed no detectable changes.

In a statement, Olde Bekkink said that the 11 missed events indicate that more work would be needed fine-tuning the algorithm before these types of monitors would be used in daily practice. If addressed and paired with an automated alert displayed by a connected device, however, the technology could be promising for Type 1 patients.

"Timely detection of impending hypoglycemia is critical to avoid severe, potentially life-threatening hypoglycemia," Olde Bekkink said. "Our proof-of-principle study found that measuring heart rate variability using a wearable device in an outpatient setting seems promising for alerting to upcoming hypoglycemia.”