Accuracy of Flash Glucose Monitoring During Postprandial Rest and Different Walking Conditions in Overweight or Obese Young Adults

Abstract

Aims: To investigate the accuracy of FreeStyle LibreTM flash glucose monitoring (FGM) relevant to plasma glucose (PG) measurements during postprandial rest and different walking conditions in overweight/obese young adults.Methods: Data of 40 overweight/obese participants from two randomized crossover studies were pooled into four trials: (1) sitting (SIT, n = 40); (2) walking continuously for 30 min initiated 20 min before individual postprandial glucose peak (PPGP) (20iP + CONT, n = 40); (3) walking continuously for 30 min initiated at PPGP (iP + CONT, n = 20); and (4) accumulated walking for 30 min initiated 20 min before PPGP (20iP + ACCU, n = 20). Paired FGM and PG were measured 4 h following breakfast.Results: The overall mean absolute relative difference (MARD) between PG and FGM readings was 16.4 ± 8.6% for SIT, 16.2 ± 4.7% for 20iP + CONT, 16.7 ± 12.2% for iP + CONT, and 19.1 ± 6.8% for 20iP + ACCU. The Bland–Altman analysis showed a bias of −1.03 mmol⋅L–1 in SIT, −0.89 mmol⋅L–1 in 20iP + CONT, −0.82 mmol⋅L–1 in iP + CONT, and −1.23 mmol⋅L–1 in 20iP + ACCU. The Clarke error grid analysis showed that 99.6–100% of the values in all trials fell within zones A and B.Conclusion: Although FGM readings underestimated PG, the FGM accuracy was overall clinically acceptable during postprandial rest and walking in overweight/obese young adults.

Patent analysis of digital sensors for continuous glucose monitoring

“…In children without diabetes who are overweight or obese, FreeStyle Libre Flash did not accurately assess glucose levels ( 64 ). Although the accuracy of the FreeStyle Libre was clinically acceptable during post-prandial rest and walking in overweight or obese young adults ( 65 ). The possibility of using FreeStyle Libre Flash during dietary treatment of patients without diabetes, during Ramadan in patients with DM1, and in pregnant women with DM1 and DM2 is shown ( 66 – 68 ).…”

Home-Based High-Intensity Interval Exercise Improves the Postprandial Glucose Response in Young Adults with Postprandial Hyperglycemia

“…We were not able to collect blood samples; hence, we could not examine the changes in hormonal responses that could affect blood glucose levels. In addition, interstitial fluid glucose concentrations tend to have a delayed response compared to blood glucose levels, and the CGM used in this study has shown that glucose concentrations tend to be low during exercise [ 38 ]. Therefore, the values of the interstitial fluid glucose concentration measured in this study may have been an underestimation of the actual glucose concentration compared with the measurement of blood glucose levels.…”

Innovative Solution or Cause for Concern? The Use of Continuous Glucose Monitors in People Not Living with Diabetes: A Narrative Review.

“…The available studies on CGM accuracy in PNLD exhibit overarching limitations, including small and unrepresentative sample sizes, [21][22][23][24][25]28 use of outdated device models [27][28] and low generalisability. Analysis is rarely supported with confidence intervals, thereby effect size, precision and reliability of the findings are uncertain.…”

“…Analysis is rarely supported with confidence intervals, thereby effect size, precision and reliability of the findings are uncertain. [21][22][23]25,28 Highly variable accuracy measured with MARD across contexts highlights the need for nuanced understanding of device performance in the target population (Table S1 in supplementary materials).…”

“…CGM precision can vary depending on user characteristics, predominantly body composition. 17,[21][22] Facets like overall body fat, body fat percentage, and Body Mass Index (BMI) are inversely associated with CGM precision. Factors stemming from shifts in subcutaneous fat and capillary networks, characteristic of obesity, potentially affect the diffusion impediment and subsequently CGM precision across different BMI catagories.…”