Wearable Device Helps Reduce Hypoglycemia

Sensor checks blood sugar every 15 minutes

A new blood sugar sensor cuts down on episodes of hypoglycemia in patients with type-1 diabetes, according to a study published in The Lancet.

The Freestyle Libre device, worn on the upper arm, automatically checks a patient’s blood sugar every 15 minutes and stores the information. A separate reader device, when held close to the sensor, displays the current glucose level, glucose readings during the past eight hours, and whether the glucose level has been rising or falling. This can be repeated as often as desired.

Patients’ “marked increase in self-monitoring frequency” after they started using the Freestyle Libre device “resulted in an almost immediate reduction in hypoglycemia both during day- and night-time,” lead investigator Dr. Jan Bolinder of the Karolinska University Hospital in Stockholm, Sweden, told Reuters Health in an email.

Bolinder and colleagues from 23 European hospitals compared the new glucose-monitoring system with conventional self-monitoring (finger stick) of blood glucose for the prevention of hypoglycemia in 239 adults with type-1 diabetes whose disease was well controlled.

The investigators enrolled 328 participants between September 4, 2014, and February 12, 2015. After the screening and baseline phase, 120 participants were randomly assigned to the intervention group and 121 to the control group, with outcomes being evaluated in 119 and 120 patients, respectively. The study’s primary outcome was the change in “time in hypoglycemia” (less than 3.9 mmol/L [70 mg/dL]) between baseline and six months in the full analysis set (i.e., all participants randomized, excluding those who had a positive pregnancy test during the study).

The subjects’ mean time in hypoglycemia decreased from 3.38 h/day at baseline to 2.03 h/day at six months in the intervention group, and from 3.44 h/day to 3.27 h/day in the control group, for a between-group difference of −1.24 h/day (P < 0·0001), corresponding to a 38% reduction in time in hypoglycemia in the intervention group.

The reductions in time spent in hypoglycemia and hyperglycemia did not translate into differences in hemoglobin A1c levels, insulin doses, or quality-of-life between the two groups, however.

“My guess is that this type of device will replace conventional [finger-prick] self-monitoring of capillary blood glucose in subjects with insulin-treated diabetes in the near future,” Bolinder told Reuters.

The Freestyle Libre sensor is manufactured by Abbott and is currently available only in Europe, although the company is working to get it approved in the United States. Abbott sponsored the new study.

Sources: Reuters; September 19, 2016; and Lancet, September 12, 2016.