Recent advances in continuous glucose monitors (CGMs) and availability of commercial CGM products to patients with type 1 and type 2 diabetes has made the use of CGM more widespread (1). CGMs work by placing a probe underneath the skin of a patient, into the interstitial space. The probe is an electroenzymatic sensor which uses glucose oxidase to break down glucose to create hydrogen peroxidase and other elements. Hydrogen peroxidase then interacts with a base metal layer of the sensor and is oxidized, which results in release of electrons which creates a current. The current is proportional to the glucose concentration. The current is measured by the probe and transmits a calculated glucose concentration to a receiving device (2). Substances that are widely distributed in body water, and thereby present in the interstitial space, potentially affect this technology. Acetaminophen and aspirin are substances that are have been known to affect the accuracy of these devices (3); however, more recently developed CGMs such as the Dexcom G6, were able to demonstrate no interference by acetaminophen (4). Patients with end stage renal disease (ESRD) who are on intermittent hemodialysis (iHD) or peritoneal dialysis (PD) undergo fluid shifts between the interstitial fluid and intravascular space during dialysis treatments. They are also often uremic and have metabolic acidosis (5). These fluid shifts, uremia, acidosis, and volume overload (increase in interstitial fluid volume due to ESRD) have the potential to impact the performance of the most advanced and commercially available CGMs; however, use of CGM in these patients has not yet been studied (3). Moderate to severe CKD is associated with both increase in insulin resistance and decrease in insulin clearance, which results in often unpredictable and labile glucose concentrations and increased risk of hypoglycemia in these patients (6). Use of CGM, and potentially hybrid closed loop insulin delivery systems that are dependent on accurate continuous glucose monitoring, has the potential to improve glucose control and quality of life in these patients (7). This study team feels that this study will be valuable in collecting preliminary data needed with the goal of validating the use of CGM in this patient population.OBJECTIVE: The specific aim is to conduct a pilot study to evaluate the accuracy of continuous glucose monitors (CGM) in End Stage Renal Disease (ESRD) patients on intermittent hemodialysis (iHD). Accuracy will be assessed by calculating the mean absolute relative difference (MARD) between CGM values and concurrent finger stick or capillary blood glucose (CBG) in these patients during hemodialysis, and on non-dialysis days.
