Accuracy of continuous glucose monitoring during exercise-related hypoglycemia in individuals with type 1 diabetes

• Published in: Frontiers in endocrinology (Lausanne) Vol. 15; p. 1352829
• Main Authors: Maytham, Kaisar, Hagelqvist, Per G, Engberg, Susanne, Forman, Julie L, Pedersen-Bjergaard, Ulrik, Knop, Filip K, Vilsbøll, Tina, Andersen, Andreas
• Format: Journal Article
• Language: English
• Published: Switzerland Frontiers Media S.A 15.04.2024
• Subjects: accuracy; Adult; Blood Glucose - analysis; Continuous Glucose Monitoring; Diabetes Mellitus, Type 1 - blood; Diabetes Mellitus, Type 1 - complications; Endocrinology; Exercise; Female; Glucose Clamp Technique; Humans; hypoglycemia; Hypoglycemia - blood; Hypoglycemia - diagnosis; Hypoglycemia - etiology; Male; mean absolute relative difference; Middle Aged; type 1 diabetes; Young Adult; accuracy; exercise; mean absolute relative difference; type 1 diabetes; continuous glucose monitoring; hypoglycemia
• ISSN: 1664-2392; 1664-2392
• DOI: 10.3389/fendo.2024.1352829

Hypoglycemia is common in individuals with type 1 diabetes, especially during exercise. We investigated the accuracy of two different continuous glucose monitoring systems during exercise-related hypoglycemia in an experimental setting. Fifteen individuals with type 1 diabetes participated in two separate euglycemic-hypoglycemic clamp days (Clamp-exercise and Clamp-rest) including five phases: 1) baseline euglycemia, 2) plasma glucose (PG) decline ± exercise, 3) 15-minute hypoglycemia ± exercise, 4) 45-minute hypoglycemia, and 5) recovery euglycemia. Interstitial PG levels were measured every five minutes, using Dexcom G6 (DG6) and FreeStyle Libre 1 (FSL1). Yellow Springs Instruments 2900 was used as PG reference method, enabling mean absolute relative difference (MARD) assessment for each phase and Clarke error grid analysis for each day. Exercise had a negative effect on FSL1 accuracy in phase 2 and 3 compared to rest (ΔMARD = +5.3 percentage points [(95% CI): 1.6, 9.1] and +13.5 percentage points [6.4, 20.5], respectively). In contrast, exercise had a positive effect on DG6 accuracy during phase 2 and 4 compared to rest (ΔMARD = -6.2 percentage points [-11.2, -1.2] and -8.4 percentage points [-12.4, -4.3], respectively). Clarke error grid analysis showed a decrease in clinically acceptable treatment decisions during Clamp-exercise for FSL1 while a contrary increase was observed for DG6. Physical exercise had clinically relevant impact on the accuracy of the investigated continuous glucose monitoring systems and their ability to accurately detect hypoglycemia.