Out of target glycemic control and severe hypoglycemia in older adults with diabetes presenting to the emergency department

BACKGROUND: Severe hypoglycemia is a frequent and high-risk complication to treatment of diabetes in older adults. It is often related to strict glycemic targets, treatment intensification, and age-related physiological vulnerability. Long-term patterns of HbA1c concentrations before hypoglycemia-related hospital admissions remain poorly described. This study aimed to characterize pre-admission HbA1c concentration value trajectories in older individuals with diabetes and to explore if these patterns indicate overtreatment. METHODS: We performed a retrospective cohort study at the Emergency Department of North Zealand Hospital, Denmark. Patients aged ≥ 65 years admitted with severe hypoglycemia between 2021 and 2024 were included. Data were obtained from electronic systems. HbA1c concentration values from 0 to 5 years before admission were analyzed. Linear regression was used to estimate HbA1c concentration changes over time, stratified by diabetes type, HbA1c category ranges, and age. RESULTS: A total of 212 patients were included (68 with type 1 diabetes and 144 with type 2 diabetes), accounting for 301 hypoglycemia-related admissions and 2,574 HbA1c measurements. HbA1c distributions suggested overtreatment in both groups, particularly in type 2 diabetes, where 49% of admissions occurred with HbA1c < 53 mmol/mol and 26% <43 mmol/mol. Conversely, 27% of type 1 diabetes and 23% of type 2 diabetes were admitted with HbA1c > 70 mmol/mol. Longitudinal analyses demonstrated significant declines in HbA1c prior to admission among patients with low HbA1c at admittance. In type 1 diabetes, HbA1c declined markedly in the lowest two HbA1c groups (- 2.85 and - 2.75 mmol/mol per 100 days), while higher baseline groups showed stable-modestly increasing trajectories. In type 2 diabetes, HbA1c declined in admissions with baseline values ≤ 53 mmol/mol (- 0.46 to - 1.86 mmol/mol per 100 days), whereas admissions with higher baseline HbA1c showed increasing trajectories, most pronounced in those with HbA1c > 53 mmol/mol (+ 0.85 mmol/mol per 100 days). CONCLUSIONS: Our data suggest that a large fraction of admissions of older adults with severe hypoglycemia are associated with overtreatment, and could potentially have been prevented by due time treatment de-intensification. CLINICAL TRIAL NUMBER: Not applicable.