Abstract P461: Concordance of Hypoglycemia Symptoms Reported in Real-Time via Smartphone and Hypoglycemia Detected Using Continuous Glucose Monitoring (CGM) in Adults With Type 2 Diabetes

Introduction: Understanding the association between low glucose readings (hypoglycemia) detected by CGM and hypoglycemic symptoms experienced by people with diabetes is critically important for diabetes management. However, tools that capture hypoglycemic symptoms in real-time are lacking. Objective: Implement a real-time hypoglycemia symptom reporting tool and examine agreement between self-reported hypoglycemia symptoms and CGM-detected hypoglycemia. Methods: We developed a survey tool for real-time reporting of symptoms via smartphone ( Fig. 1A ) using REDCap, and implemented this tool in an ongoing, randomized clinical trial of adults with type 2 diabetes, the Dietary Approaches to Stop Hypertension for Diabetes (DASH4D) trial. DASH4D participants wore a CGM sensor (Abbott Libre Pro) for up to 5 periods (max 2-weeks per period), and we offered the option to report symptoms using the real-time survey tool during each CGM wear. We examined the concordance of real-time reported symptoms and CGM-detected hypoglycemia (glucose <70 mg/dL for > 15 minutes) ( Fig. 1B ). Concordance was defined as CGM-detected hypoglycemia occurring within 30 minutes before or after a reported symptom. Results: Of 159 participants who wore a CGM, 114 (72%; mean age 64 years; 86% Black; 64% female) used the real-time symptom reporting tool (the remainder used a paper-based booklet). Across all CGM wear-periods (N=280), participants reported a mean 1.94 symptoms per period. Fatigue was the most common (37 occurrences); unsteadiness and passing out were not reported ( Fig. 1C ). The overall concordance between self-reported symptoms and CGM-detected hypoglycemia was 3% ( Fig. 1D ). Conclusion: We developed a simple and secure smartphone-based tool allowing patients with diabetes to report hypoglycemic symptoms in real-time. Concordance of CGM-detected hypoglycemia with symptoms was low, indicating substantial disconnect between perceived symptoms and CGM-detected hypoglycemic events among adults with type 2 diabetes. [NCT04286555]