Real-world glycaemic outcomes in patients with type 1 diabetes using glucose sensors-Experience from a single centre in Dublin

Aims: To evaluate changes in glycated haemoglobin (HbA1c) and sensor-based glycaemic metrics after glucose sensor commencement in adults with T1D.Methods: We performed a retrospective observational single-centre study on HbA1c, and sensor-based glycaemic data following the initiation of continuous glucose monitoring (CGM) in adults with T1D (n = 209).Results: We observed an overall improvement in HbA1c from 66 (59-78) mmol/mol [8.2 (7.5-9.3)%] pre-sensor to 60 (53-71) mmol/mol [7.6 (7.0-8.6)%] on-sensor (p < .001). The pre-sensor HbA1c improved from 66 (57-74) mmol/mol [8.2 (7.4-8.9)%] to 62 (54-71) mmol/mol [7.8 (7.1-8.7)%] within the first year of usage to 60 (53-69) mmol/mol [7.6 (7.0-8.4)%] in the following year (n = 121, p < .001). RT-CGM-user had a significant improvement in HbA1c (Dexcom G6; p < .001, r = 0.33 and Guardian 3; p < .001, r = 0.59) while a non-significant reduction was seen in FGM-user (Libre 1; p = .279). Both MDI (p < .001, r = 0.33) and CSII group (p < .001, r = 0.41) also demonstrated significant HbA1c improvement. Patients with pre-sensor HbA1c of >= 64 mmol/mol [8.0%] (n = 125), had attenuation of pre-sensor HbA1c from 75 (68-83) mmol/mol [9.0 (8.4-9.7)%] to 67 (59-75) mmol/mol [8.2 (7.6-9.0)%] (p < .001, r = 0.44). Altogether, 25.8% of patients achieved the recommended HbA1c goal of <= 53 mmol/mol and 16.7% attained the recommended >= 70% time in range (3.9-10.0 mmol/L).Conclusions: Our study demonstrated that minimally invasive glucose sensor technology in adults with T1D is associated with improvement in glycaemic outcomes. However, despite significant improvements in HbA1c, achieving the recommended goals for all glycaemic metrics remained challenging.