966-P: The Long-Term Impact of a Flash Glucose Monitoring System on Glycemic Control

Background: Tight control of blood glucose with lower frequency of hypoglycemia is required to prevent diabetic complications. However, HbA1c doesn’t reflect intraday- and interday glycemic excursions. The aim of this study is to characterize fluctuations in blood glucose levels with the flash glucose monitoring (FGM) and to observe the course of patients in whom this information was used to direct their daily medical treatment.

Methods: This 52-week, retrospective observational study involved diabetic patients who wore the FGM device (FreeStyle Libre Pro®) for 2 weeks. Changes in HbA1c were observed by clinical phenotypes of diabetes and manifestations of glucose variability. The frequency of hypoglycemia was analyzed in patients who had performed SMBG. We divided patients into two groups (those who received a check-up after 1 week or 2 weeks after starting to wear the device) and compared their change in of HbA1c. The differences of HbA1c change from baseline were analyzed by the t-test and P-values < 0.05 were considered significant.

Results: Of 114 patients who received a FGM device, 79 were enrolled in the study (type 1: n=14, type 2: n=62, other: n=3). Overall, the mean HbA1c (%) was significantly decreased at week 12 compared with baseline (8.35 vs. 7.61, P<0.001) and this reduction was continued at week 24 (7.78, P<0.001) and week 52 (7.62, P<0.001). Only nutritional guidance with FGM-use was associated with a similar reduction in HbA1c at week 52 compared with medication regimen changes (0.77 vs. 0.68, P=0.37). The frequency of hypoglycemia was lower at week 12, 24, and 52 compared with baseline. A trend towards a greater reduction in HbA1c at week 12 was observed in patients who received a check-up 1 week after initiating to wear FGM device comparted with those with a check-up 2 weeks afterwards (0.94 vs. 0.72, p=0.14).

Conclusion: Visualization of glucose variability with a FGM device was safe and has the potential to improve glucose profiles for a long term even though this method was only a temporary measure.