Accuracy of a continuous glucose monitoring system in people with diabetes on peritoneal dialysis

Background Lack of data on the accuracy of continuous glucose monitoring systems currently limits their usage in people with diabetes on peritoneal dialysis (PD). Aim We aimed to assess the analytical and clinical accuracy of the FreeStyle Libre (FSL) continuous glucose monitoring system in people with diabetes on PD. Methods 12 participants using Icodextrin in their PD regime were recruited to a single-centre observational study. They wore a blinded research model of the FSL for 10 days. Results from the FSL were compared with venous glucose measured on a Yellow Springs Instrument (YSI) and self-monitored capillary blood glucose (SMBG) recorded five times per day over the 10-day study. Results The mean absolute relative difference from 84 FSL-YSI matched pairs was 9.8% (95% CI 8.6–11.1) and from 416 FSL-SMBG matched pairs, it was 17.3% (95% CI 16.24–18.43). The systematic error for the FSL as determined by Bland–Altman analysis was −0.6 ± 1.0 mmol/l compared with YSI and −1.4 ± 1.9 mmol/l compared with SMBG. With regard clinical accuracy, compared with YSI and SMBG, respectively, 100% and 99.9% of sensor values were in clinically acceptable zones A and B of Parkes consensus error grid. Conclusion We demonstrated satisfactory performance of the FSL monitoring system by both analytical and clinical metrics in this cohort of PD patients using treatment prescriptions including Icodextrin-based fluids. Larger studies are now needed to provide clinicians with appropriate reassurance if this technology is to be used with confidence in people on PD.