FreeStyle Libre Glucose Monitor Reduces Hospitalizations in Diabetes

Miriam E. Tucker

June 14, 2020

The Abbott FreeStyle Libre glucose monitoring system significantly reduced hospitalizations for diabetic ketoacidosis (DKA), diabetes-related emergencies, and all-cause hospitalizations among patients with diabetes, data from two new studies indicate.

The results were presented June 13 during the virtual American Diabetes Association (ADA) 80th Scientific Sessions.

One large database analysis, from France, revealed that use of the Libre system halved hospitalization rates for DKA among people with type 1 or type 2 diabetes.

In the other study, a retrospective analysis of data from over 1200 insulin-treated individuals with type 2 diabetes in the United States, use of the Libre was associated with significant reductions in both hospitalizations for acute diabetes-related emergency events and all-cause hospitalizations.

The Libre system reads glucose levels through a sensor worn on the back of the upper arm for up to 14 days. Users wave a scanner over the device to obtain a reading.

Asked to comment, Nicholas Argento, MD, diabetes technology director at Maryland Endocrine and Diabetes, Columbia, told Medscape Medical News: "One of the biggest problems with access to continuous glucose monitoring is cost. Payers need to see that there's some cost-saving to offset the cost of paying for these devices. I think both of these studies are important for that reason."

However, Argento also said he recommends that people with type 1 diabetes use the Dexcom continuous glucose monitor (CGM) if possible rather than the Libre, despite the former's higher cost, because it has an alarm feature that the Libre doesn't and is more accurate in the hypoglycemic range. (The Freestyle Libre 2, with optional glucose alarms, is available in several European countries but not the United States.) 

Large French Study: Libre Cuts DKA Hospitalizations by 50%

The FreeStyle Libre system has been reimbursed in France since June 1, 2017 for patients over 4 years of age with type 1 or type 2 diabetes who take at least 3 insulin injections per day or use an insulin pump.

The new results were presented by Ronan Roussel, MD, PhD, chief of the endocrinology, diabetes, and nutrition department at Hôpital Bichat, Fédération de Diabétologie, AP-HP, Paris, France.

The DKA hospitalization data Roussel reported were part of a larger longitudinal retrospective cohort study looking at overall prescribing and use of the Libre system, and its impact on healthcare outcomes and associated costs in standard practice in France. The data came from a large nationwide claims database containing all healthcare expenses for over 66 million people.

The current study participants were 74,076 individuals with at least a full year of follow-up beginning in 2017 with the date of first reimbursement for the FreeStyle Libre system. Of those, 44.8% (33,203) had type 1 diabetes and 55.2% (40,955) had type 2 diabetes.

Prior to initiation of Libre use, about a quarter of each group was using 0 fingerstick test strips per day, about 19% of the type 1 diabetes group and 28% of the type 2 diabetes group were using 1-3 strips per day, and about half of both groups were using 4 or more strips per day.

Compared with the year prior to the date of first reimbursement for the Libre, hospitalization rates for DKA during the first year of Libre use fell by 52% in the type 1 diabetes group, from 5.46 to 2.59 per 100 patient-years, and by 47% in the type 2 diabetes group, from 1.70 to 0.90 per 100 patient-years.

The impact of Libre on DKA hospitalizations was most dramatic among those not using any test strips prior to Libre use, with a 60% reduction for the type 1 diabetes group (8.31 to 3.31 per 100 patient-years) and a 51% reduction in the type 2 diabetes group (2.51 to 1.23 per 100 patient-years).

But interestingly, the next-biggest impact was among those who had been using more than 5 test strips per day, with drops of 59% among those with type 1 diabetes (5.55 to 2.26 per 100 patient-years) and 52% in the type 2 diabetes group (1.88 to 0.90 per 100 patient-years).

This finding is important for the United States, Argento said, because some insurers including Medicare require that the patient performs at least 4 fingerstick glucose measurements per day to qualify for reimbursement for the Libre or any CGM system.

"I think that speaks to the importance of not requiring that patients first show they're frequently doing self-blood glucose monitoring before they can get these devices," he observed. 

The large benefit in the high strip use group is interesting too, Argento said. "It's a different group of people. They're more engaged in their care...This U-shaped curve they showed is fascinating."

Reductions in DKA hospitalizations were also similar between patients using insulin pumps and those using multiple daily injections of insulin, Roussel reported.

"It is plausible that use of the FreeStyle Libre system allowed people to detect and limit persistent hyperglycemia, and subsequently ketoacidosis," Roussel said.

"This analysis has significant implications for patient-centered clinical care in diabetes and also for long-term health economic outcomes in the treatment of diabetes at a national level."

All-Cause Hospitalizations Drop 30% With Libre in Type 2 Diabetes

Richard M. Bergenstal, MD, executive director of the International Diabetes Center at Park Nicollet, Minneapolis, Minnesota, presented the US results, obtained from the IBM Watson Health MarketScan, a database of commercial and Medicare supplemental insurance claims for over 30 million Americans.

The study population included 2463 patients with type 2 diabetes using basal-bolus daily insulin injections but who had not previously used Libre or any other CGM, and for whom data were available 6 months prior to and after Libre initiation.

Compared with 6 months prior to Libre use, the number of acute diabetes-related events — including hyperglycemia, hypoglycemia, DKA, hypoglycemic coma, and hyperosmolarity — in the subsequent 6 months dropped by 60%, from 0.180 to 0.072 events per patient-year (P < .001).

Similarly significant reductions were seen between males and females, and among those aged ≥ 50 years or < 50 years.   

All-cause hospitalizations also significantly dropped by 33% (P < 0.001), from 0.420 to 0.283 events per patient-year. Among diagnostic codes for the hospitalizations, circulatory system causes remained number one during both time periods, with little change from pre-Libre to during Libre use.

However, "endocrine, nutritional, and metabolism system" codes dropped from the second position pre-Libre (6.4 events/100 patient-years) down to the fifth position (2.6 events/100 patient-years).

And, Bergenstal noted, other major diagnostic categories that also dropped included respiratory (3.5 to 2.1 events/100 patient-years), kidney and urinary tract (3.3 to 1.7 events/100 patient-years), and hepatobiliary system and pancreas (2.4 to 1.4 events/100 patient-years).

"We're seeing a resurgence of certain types of complications, but all of these were reduced in the 6 months after Libre," Bergenstal pointed out.

And, pertinent to the current COVID-19 situation, "infectious and parasitic disease and disorders" dropped as well, from 4.8 to 2.8 per 100 patient-years.

Argento commented: "The fact that infections went down speaks to something that is important right now. Hyperglycemia impairs immune function chronically, but also patients who become ill and their blood glucose deteriorates rapidly are much more likely to have a poor outcome regardless of infection. There are data for COVID-19 now."

"These findings provide compelling support for use of [Libre] to improve both clinical outcomes and potentially reduce costs in this patient population," Bergenstal concluded.

Roussel has reported being on advisory panels for Abbott, AstraZeneca, Diabnext, Eli Lilly, Merck, Mundipharma International, Novo Nordisk, and Sanofi-Aventis. Bergenstal has reported being a consultant for Ascensia Diabetes Care, Johnson & Johnson, and has other relationships with Abbott, Dexcom, Hygieia, Lilly Diabetes, Medtronic, Novo Nordisk, Onduo, Roche Diabetes Care, Sanofi, and UnitedHealth Group. Argento has reported consulting and being on speaker bureaus for Omnipod, Eli Lilly, Novo Nordisk, Dexcom, and Boehringer Ingelheim.

ADA 2020 Scientific Sessions. Presented June 13, 2020. Abstracts 68-OR, 69-OR.

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