Accuracy of a Continuous Glucose Monitoring System Under Hyperglycemic Challenge in Chinese Hospitalized Patients With Diabetes

BACKGROUND: To assess the accuracy of a continuous glucose monitoring (CGM) system under hyperglycemic conditions, we conducted a steamed bread meal tolerance test (SBMTT) in hospitalized patients aged 18 years or older with type 1and 2 diabetes mellitus. METHODS: Hospitalized adults with diabetes wore a Sibionics CGM (GS1) sensor, which was placed at least 48 hours prior to the test. Participants subsequently underwent an SBMTT containing 75 g of carbohydrates. Plasma glucose (PG) was measured at 0, 30, 60, 120, and 180 minutes. Accuracy was evaluated by calculating the mean absolute relative difference (MARD), %15/15, %20/20, %30/30, and %40/40 agreement rates. Clinical accuracy was assessed using the Diabetes Technology Society (DTS) error grid analysis. The time lag between CGM and PG was calculated. RESULTS: A total of 580 matched CGM-PG pairs from 116 participants were analyzed. The overall MARD was 11.83%, with agreement rates of 69.5% (%15/15), 86.2% (%20/20), 98.3% (%30/30), and 99.7% (%40/40). Diabetes Technology Society error grid analysis showed 100% of the CGM points falling into zones A and B, with 86% in zone A and 14% in zone B. After minimizing MARD, the overall CGM lag time was 5 minutes, but it increased during rapid glucose rise (0-60 minutes), reaching 10 minutes at 30 minutes and 20 minutes at 60 minutes. CONCLUSIONS: Continuous glucose monitoring maintained good accuracy during hyperglycemic challenges in hospitalized patients with diabetes. The time lag was influenced by the rate of glucose change, showing prolongation during the rapid glucose rise phase (0-60 minutes).