Aims: Frequent glucose testing is required for optimal management of type 1 diabetes (T1D). Limited data are available regarding real-world experience of the novel technology for monitoring by continuous interstitial fluid glucose (IFG), using flash glucose-sensing technology (FSL-CGM). We aimed to assess the effect of FSL-CGM in a real-life clinical setting on glycemic control parameters, compliance, and adverse events among pediatric and young adult T1D patients.
Methods: This observational multi-center study assessed FSL-CGM use (6-12 months) in T1D patients (mean ± SD age 13.4 ± 4.9 years) who purchased the device out-of-pocket. Outcome measures included HbA1c, mean IFG levels, CGM metrics [time in hypoglycemia (< 54 mg/dL; < 3 mmol/L), in target range (70-180 mg/dL; 3.9-10 mmol/L), and in hyperglycemia > 240 mg/dL; > 13.3 mmol/L)], frequency of self-monitoring of blood glucose, acute complications, skin reactions, and reasons for initiation/discontinuation.
Results: Among patients with regular use of the FSL-CGM (n = 59), mean HbA1c decreased from 8.86 ± 0.23 to 8.05 ± 0.2% (73.3-64.5 mmol/mol) in 3 months (p = 0.0001) and plateaued thereafter. A clinically significant reduction in HbA1c (defined as a decrease of ≥ 0.5%) was associated with shorter diabetes duration. Of 71 patients who initiated use of the FSL-CGM, 12 (16.9%) discontinued during the study period. No statistically significant changes were found after FSL-CGM use, in mean and standard deviation IFG levels, and in time of glucose levels in target, hypoglycemia, and hyperglycemia ranges. One patient with hypoglycemia unawareness was found dead-in-bed while using FSL-CGM.
Conclusions: Real-life observational data in a self-selected young T1D population demonstrated a significant and sustained reduction in HbA1c with FSL-CGM in one-third of the participants. Surveillance of glucose monitoring should be individualized, especially for patients with hypoglycemia unawareness.
Keywords: Continuous glucose monitoring; Flash glucose monitoring system; FreeStyle libre; Hypoglycemia unawareness; Type 1 diabetes.