People with diabetes-related ulcers may benefit from hyperbaric oxygen (HBO2) therapy and from continuous glucose monitoring (CGM). Although blood glucose (BG) meters based on glucose oxidase (GO) underestimate BG at high pO2, BG meters based on glucose dehydrogenase (GD) do not. We therefore examined the performance of a GO-based continuous glucose monitoring (CGM) system in comparison to GO-based and GD-based BG systems in HBO2 and normobaric air (NBAir) environments.
Twenty-six volunteers without diabetes wore Dexcom G6 CGM systems and provided periodic blood samples while breathing NBAir (pO2 21.28 kPa) and during a standard HBO2 treatment consisting of three 30-minute intervals of HBO2 (pO2 243.18 kPa) separated by two 5-minute intervals of HBAir (pO2 51.07 kPa). Accuracy of the CGM and GO-based BG meter were assessed by comparisons with the GD-based values.
The MARD for the CGM system was 15.96% and 8.52% for the GO-based meter. Compared to NBAir, HBO2 exposure resulted in significantly higher CGM values and significantly lower GO-based meter values. Pre-HBO2 and post-HBO2 values obtained in NBAir were significantly different when measured by CGM or the GO-based meter (Table).
Device | HBO2 vs. NBAir | NBAir before vs. after HBO2 |
---|---|---|
CGM | +3.76 mg/dL (p<0.001) | +4.13 mg/dL (p=0.015) |
GO-Based | -10.38 mg/dL (p<0.001) | -9.04 mg/dL (p<0.001) |
GD-Based | +1.17 mg/dL (p=0.076) | -5.00 mg/dL (p=0.039) |
HBO2 exposure results in statistically significant differences in glucose measurements obtained with GO-based devices, but not a GD-based device. Standard HBO2 treatment results in statistically significant effects on glucose concentrations. These differences are of unlikely clinical significance.