28-LB: RTCGM Performance at Different Sensor Wear Sites during Prolonged Aerobic Exercise

Strenuous exercise may disrupt the local equilibria between vascular and interstitial glucose concentrations. We measured interstitial glucose levels during aerobic exercise in different anatomical regions with continuous glucose monitoring (CGM) sensors and compared them to capillary blood glucose (BG) levels. We enrolled 10 individuals, 7 with type 1 diabetes (T1D) and 3 without (healthy volunteers), for a 50-mile bicycle ride. Three CGM sensors (Dexcom G6) were placed on each participant, with one each in the upper arm, abdomen and thigh. BG values were obtained at the start of the ride and every 30 minutes thereafter. Accuracy of CGM levels was assessed for each insertion site as the mean absolute relative difference (MARD) and bias versus contemporaneous BG levels. Table shows that arm-worn sensors were more accurate in terms of MARD, and also had smaller numerical bias, than sensors placed in either the abdomen or thigh. Sensor accuracy was not significantly affected by the presence or absence of a diabetes diagnosis and accuracy metrics were consistent with those reported in the device’s instructions for use. CGM users may benefit from wearing sensors on the arm during sustained bicycle rides. Disclosure M. Mueller-korbsch: Research Support; Self; Dexcom, Inc., Menarini Group, Novo Nordisk Inc. L. Fruehwald: None. M. Heer: None. G. Rega-kaun: None. M. Fangmeyer-binder: None. P. Fasching: None.