FreeStyle Libre FGM in Patients with Type 2 Diabetes

Patients with type 2 diabetes routinely use self-monitoring of blood glucose, but what if there was a better option? Study looks at the impact of FreeStyle Libre FGM (flash glucose monitoring) system.

Self-monitoring of blood glucose (SMBG) is used by patients with type 2 diabetes to measure their glucose levels and, in turn, adjust their insulin doses as needed. While SMBG has its known drawbacks, it is still considered the standard of care if a patient is using multiple injections of insulin a day. In contrast, patients with type 1 diabetes typically rely on continuous glucose monitoring (CGM), but what about its use in patients with type 2 diabetes? Previous studies have researched the use of CGM in patients with type 2 diabetes not using insulin, and after three months saw a significant decrease in their HbA1C. Others have found no significant drop in HbA1C. 

Researchers wanted to determine the efficacy and advantages of using the FreeStyle Libre, a flash glucose monitoring (FGM) system, reading real-time glucose levels, in patients with type 2 diabetes who were using multiple insulin injections to determine its impact on treatment satisfaction and diabetes control. The study was an open-label randomized controlled trial over ten weeks, with 101 total patients with type 2 diabetes, 53 in the intervention group and 48 in the control group. The intervention group used the FGM system and were to scan every 8 hours. The data was downloaded every 2-4 weeks to be reviewed at inpatient visits. Those in the control group continued their routine of SMBG at least four times a day, specifically using FreeStyle Optium Neo glucometers. If patients experienced symptoms of hypoglycemia, both groups were to use FreeStyle Optium Neo glucometers and record it. Also, to account for asymptomatic hypoglycemia, each group was asked to test their blood glucose levels seven times a day, once per week, the day before their visit. The primary outcome was to determine the impact of FGM on treatment satisfaction; secondarily, to also evaluate changes in HbA1C, quality of life score, the achievement of target A1C scores, and changes in total hypoglycemic events.

To evaluate the diabetes treatment regimen in terms of overall satisfaction, convenience, flexibility, understanding of diabetes, willingness to recommend to others, and willingness to continue treatment, DTSQ was used. The higher the score, the higher the treatment satisfaction. The DTSQ change version (DTSQc) analyzed the current treatment experience with the previous treatment experience used before the start of the trial. Scores ranged from +3 to -3, with 0 meaning no change. The higher the score, the more satisfied now. Quality of life was evaluated using ADDQoL-19. Lastly, at the end of the study, patients were given a Libre user evaluation questionnaire.

Continuous variables were the mean and the SD, and the categorical as percentages. An intent-to-treat (ITT) analysis was run to determine the change in HbA1C after ten weeks between the two groups. To determine its effect, multivariate linear regression was performed with adjustment for HbA1C at baseline. A non-prespecified post hoc analysis was done to compare the proportion of those with a decrease in HbA1C between the groups.

Patient satisfaction in both groups was found to be high (P = 0.053). In the intervention group, 87.5% were very satisfied, and 12.5% were moderately satisfied, with none below that. Comparing the groups, the intervention group found their treatment to be more flexible (P = 0.019) and would recommend it (P = 0.023). Also, in the intervention group, the frequency of hypoglycemia significantly improved (P = 0.013). After ten weeks, there were no significant changes in quality of life between the two groups.

Comparing glycemic control between the two groups, the intervention group showed a reduction of -0.82% in HbA1C compared to the control group with a reduction of -0.33% (P = 0.005). After adjustment of baseline HbA1C, the results were still found to be significant (P < 0.0001). The non-prespecified post hoc analysis showed 68.6% of the intervention group had a significant decrease in HbA1C of at least 0.5%, with only 30.2% in the control group (P < 0.001). Furthermore, 39.2% of the intervention group had a decrease in HbA1C of at least 1%, with only 18.6% in the control group (P = 0.023). Lastly, in the intervention group, between the frequency of glucose scans and reduction in HbA1C, no correlation was shown (P = 0.52).

The authors found that overall, each group had high satisfaction with their treatment. Their patients were required to visit regularly, and both had high satisfaction before the study, which may result in the reduction of an increase in satisfaction. The FGM technology did have higher satisfaction, with the intervention group finding it to be more flexible and would recommend it to others. In terms of HbA1c reduction, the intervention had a significantly better reduction of 0.82% compared to the control group. The number of patients with an HbA1C reduced by at least 1% in the intervention group was more than double seen in the control group. The authors acknowledged the power of this study might have been undermined due to patients not completing the questionnaires. Also, the inclusion criteria were expanded, accepting a wider range of HbA1C values (7.4% – 10.2%), giving a lower mean HbA1C in the control group, but did not adversely affect the data. Future studies should similarly evaluate the FreeStyle Libre 2 system and determine any improved effects on glycemic control.

Practice Pearls:

• Patients with type 2 diabetes found the FreeStyle Libre FGM system to be highly satisfying, more flexible, and would recommend it to others.
• Using FreeStyle Libre FGM not only increased satisfaction but also significantly lowered HbA1C by at least 0.5% up to at least 1%.
• FGM technology should be considered in patients with type 2 diabetes who are willing to accept the change.

Yaron, Marianna, et al. Effect of Flash Glucose Monitoring Technology on Glycemic Control and Treatment Satisfaction in Patients With Type 2 Diabetes. Diabetes Care. 2019 April 29.

Emma Kammerer, L|E|C|O|M Bradenton School of Pharmacy, PharmD Candidate