Accuracy of Flash Glucose Monitoring in Patients with Diabetes Mellitus on Hemodialysis and Its Relationship with Hydration Status

Abstract

Background: The use of flash-glucose monitoring system FreeStyle Libre (FSL) has demonstrated benefits in metabolic control and quality of life in different populations with diabetes mellitus (DM), being funded in many countries. Due to this, DM subjects on hemodialysis (HD) are using FSL despite the accuracy in this population being unclear. The aims of the present study are to assess the accuracy of FSL in DM subjects on HD, its relationship to hydration status, and patient satisfaction. Material and Methods: A prospective study in 16 patients with DM in a chronic HD program was conducted. Interstitial glucose values from FSL during a 14-day period were compared to capillary glucose measurements obtained at the same time. Hydration status was measured via bioimpedance spectroscopy. Satisfaction with FSL was obtained from an ad hoc satisfaction questionnaire. Results: A total of 766 paired interstitial and capillary glucose levels were analyzed. A correlation coefficient of 0.936 was determined and a mean absolute relative difference (MARD) value of 23%, increasing to 29% during HD. MARD was not related to hydration status. Interstitial glucose values were lower during HD (100.1 ± 17 mg/dL) than within the 12 hours after (125.1 ± 39 mg/dL; P = .012) and the days without HD (134.2 ± 32 mg/dL; P = .001). Subjects showed high satisfaction with FSL. Conclusion: The accuracy of FSL in DM patients on HD is lower than in other populations, especially during HD sessions and is not related with the hydration status. Despite this, the degree of patient satisfaction with FSL is very high.

Accuracy of Flash Glucose Monitoring in Hemodialysis Patients With and Without Diabetes Mellitus

“…Indeed, this correction term considerably improved the performance of FGM and yielded a MARD and results on Surveillance’s error grid which were equivalent to the respective measures reported for non-dialysis patients with T1DM and T2DM 6 25 28 36 and in agreement with current recommendations and standards for CGM (ISO 1597:2013). While our study is the first to evaluate a correction term for the systematic measurement bias of FGM in hemodialysis patients, all three studies that previously validated FGM in hemodialysis patients found a near-identical systematic bias (Yajima et al: −19.9 mg/dL=−1.10 mmol/L, Matoba et al: −18.4 mg/dL=−1.02 mmol/L; Genua et al not reported in numbers by but visible from the correlation graph) 33 34 35 . An individual correction term derived for every patient from a number of paired measurements might allow for a more precise, individualized correction since the mean difference, MAD, and MARD between FGM and SMBG varied considerably between patients (Supplement Table 1).…”

“…FGM would be particularly useful in hemodialysis patients due to its factory calibration eliminating the need for SMBG. A total of six studies have reported the use of FGM in hemodialysis patients so far [30][31][32][33][34][35], however, only three of these reported validation against SMBG [33][34][35].…”

“…Indeed, this correction term considerably improved the performance of FGM and yielded a MARD and results on Surveillance's error grid which were equivalent to the respective measures reported for non-dialysis patients with T1DM and T2DM [6,25,28,36] and in agreement with current recommendations and standards for CGM (ISO 1597:2013). While our study is the first to evaluate a correction term for the systematic [33][34][35]. An individual correction term derived for every patient from a number of paired measurements might allow for a more precise, individualized correction since the mean difference, MAD, and MARD between FGM and SMBG varied considerably between patients (Supplement Table 1).…”

“…FGM would be particularly useful in hemodialysis patients due to its factory calibration eliminating the need for SMBG. A total of six studies have reported the use of FGM in hemodialysis patients so far 30 31 32 33 34 35 , however, only three of these reported validations against SMBG 33 34 35 . Compared to these studies, we found a somewhat higher but similar precision of FGM, as expressed by MAD and MARD.…”

Making sense of glucose sensors in end-stage kidney disease: A review

“…showed poorer accuracy with the Abbott Libre CGM ( 96 ). The accuracy in patients on hemodialysis is not affected by hydration status measured via impedance spectroscopy ( 97 ). A small study in twelve patients ( 98 ) showed better MARD at the beginning of the dialysis treatment (r=0.731) compared to the end of the treatment session (r=0.513), and overall 90% of the paired measurments were in the zones A/B (clinically accurate or no risk from error) of the Clarke error grid.…”