Impaired Awareness and Symptomatology of Hypoglycemia in Adults With Type 1 Diabetes Using Continuous Glucose Monitoring

CONTEXT AND OBJECTIVE: Sparse large-scale studies have characterized hypoglycemia symptomatology in adults with type 1 diabetes (T1D) who use continuous glucose monitoring (CGM). This research aimed to evaluate the relationship of impaired awareness of hypoglycemia (IAH) with hypoglycemia symptomatology and frequency in this population. DESIGN: A cross-sectional survey was conducted in 2023. HypoA-Q was used to evaluate hypoglycemia frequency, symptomatology, and awareness. SETTING & PARTICIPANTS: Registrants who used CGM in the T1D Exchange, a U.S. national T1D registry. RESULTS: Surveys were completed by 1480 adults with T1D who used CGM (53% female; mean diabetes duration 26 years). Compared to those with intact hypoglycemia awareness, IAH was associated with less frequent hypoglycemia symptom presentation across various glucose levels and lower glucose concentrations for first presenting hypoglycemia symptoms when awake (P < .05 for all). More than 70% of individuals with IAH did not regularly experience symptoms during episodes with glucose <54 mg/dL. When asleep, those with IAH were less frequently awoken by symptoms, more frequently awoken by others who recognized their hypoglycemia, and more frequently acknowledged hypoglycemia after an episode (P < .05 for all) despite using CGM. With reduced symptoms, both when awake and asleep, those with IAH experienced more hypoglycemic episodes that they were unable to self-treat than those with intact awareness (P < .05). CONCLUSION: IAH continues to be associated with a significant reduction in detection of hypoglycemia symptoms, both when awake and asleep, in adults using CGM. Current diabetes technologies do not fully protect adults with T1D from hypoglycemia.