Assessment of factors that determine the mean absolute relative difference in flash glucose monitoring with reference to plasma glucose levels in Japanese subjects without diabetes

Abstract

The Abbott FreeStyle Libre flash glucose monitoring system (FGM) is a recently introduced, but widespread continuous glucose monitoring system. While its mean absolute relative difference (MARD) value indicating its accuracy is acceptable with reference to the self-monitoring of blood glucose (SMBG) levels, few reports have examined the MARD in sensor glucose values of FGM (FGM-SG) with reference to plasma glucose (PG) levels and the factors determining it. We performed oral glucose tolerance tests (OGTTs) in 25 Japanese subjects without diabetes. Parkes error grid analyses showed that FGM-SG with either SMBG or PG levels as a reference met International Organization for Standardization criteria. The MARD in FGM-SG with reference to SMBG levels was 10.9 ± 4.1% during OGTTs. Surprisingly, the MARD in FGM-SG with reference to PG levels was 20.3 ± 10.3% during OGTTs, revealing a discrepancy in the accuracy of FGM-SG compared with that of PG levels; moreover, the MARD showed negative correlations with fasting blood sugar level, homeostasis model assessment insulin resistance index, and body mass index (BMI). Multiple regression analyses revealed that BMI contributed the most to the MARD when FGM-SG and PG level were compared, as lean individuals have a greater MARD regardless of glucose levels. Inaccurate FGM data could potentially increase the risk of inappropriate treatment; consideration of such factors is critical to ensure reliable FGM values.

Impact of factory‐calibrated Freestyle Libre System with new glucose algorithm measurement accuracy and clinical performance in children with type 1 diabetes during summer camp

“…The second source of the gap in laboratory and real‐life MARDs might be due to biologically‐relevant differences between these conditions 24 . In our study, we demonstrated that a number of factors might impair FSL accuracy 18 . First, we noted significantly worse MARD during daytime hours (9:00‐23:59—MARD: 12.8%) than at night (0:00‐8:59—MARD: 8.9%).…”

“…During the 2019 camp five clinical factors were investigated as potentially disturbing FSL‐B accuracy 18 . We demonstrated that FSL‐B accuracy was decreased during daytime as opposed to nighttime (MARD 12.82% ± 11.38% vs 8.88% ± 9.01%, P < .0001), within 2‐3 hours after main meals as opposed to just before main meals (13.26% ± 11.96% vs 10.11% ± 9.66%, P < .0001), during prolonged physical activity vs everyday conditions (16.6% ± 18.02% vs 11.43% ± 9.74%, P < .0001), and in patients with adverse skin reactions (13.48% ± 12.89% vs 11.14% ± 10.49%, P = .0129).…”

Performance of intermittently scanned continuous glucose monitoring systems in people with type 1 diabetes: A pooled analysis

“…Although most studies have shown that isCGM systems are within a safe clinical range [10][11][12] conclusive large-scale assessments of isCGM performance and the impact of the rate of change in glucose are currently lacking. Therefore, the aim of this pooled analysis was to assess isCGM (FreeStyle Libre 1; Abbott Diabetes Care, Alameda, California) performance and the rate of change in sensor glucose in a cohort of children, adolescents, and adults with type 1 diabetes.…”