Switching to an advanced hybrid closed-loop system in real-world practice improves hypoglycemia awareness and metabolic control in adults with type 1 diabetes, particularly in those with impaired perception of hypoglycemia symptoms

Aims: To evaluate the efficacy of an advance closed-loop (AHCL) system in restoring awareness of hypoglycemia in patients with type 1 diabetes (T1D).

Methods: We conducted a prospective study including 46 subjects with T1D flash glucose monitoring (FGM) or continuous glucose monitoring (CGM) switching to a Minimed 780G® system. Patients were classified in three groups according to the therapy used before switching to Minimed® 780G: multiple dose insulin (MDI) therapy + FGM (n = 6), continuous subcutaneous insulin infusion + FGM (n = 21), and sensor-augmented pump with predictive low-glucose suspend (n = 19). FGM/CGM data were analyzed at baseline, after 2 and 6 months on AHCL. Clarke's score of hypoglycemia awareness was compared at baseline and 6 months recordings. We also compared the efficacy of the AHCL system in improving A_1c among patients with appropriate perception of symptoms of hypoglycemia compared to those presenting with impaired awareness of hypoglycemia (IAH).

Results: Participants had a mean age of 37 ± 15 and a diabetes duration of 20 ± 10 years. At baseline, 12 patients (27%) showed IAH as defined by a Clarke's score ≥ 3. Patients with IAH were older and had lower estimated glomerular filtration rate (eGFR) compared with those who did not have IAH; with no differences in baseline CGM metrics or A_1c. An overall decrease in A_1c was observed after 6 months on AHCL system (from 6.9 ± 0.5% to 6.7 ± 0.6%, P < 0.001), regardless of prior insulin therapy. The improvement in metabolic control was greater in patients with IAH, showing a reduction in A_1c from 6.9 ± 0.5 to 6.4 ± 0.4% vs 6.9 ± 0.5 to 6.8 ± 0.6% (P = 0.003), showing a parallel increase in total daily boluses of insulin and automatic bolus correction administered by the AHCL system. In patients with IAH Clarke's score decreased from 3.6 ± 0.8 at baseline to 1.9 ± 1.6 after 6 months (P < 0.001). After 6 months on AHCL system, only 3 patients (7%) presented with a Clarke's score ≥ 3, resulting in an absolute risk reduction of 20% (95% confidence interval: 7-32) of having IAH.

Conclusions: Switching from any type of insulin administration to AHCL system improves restoration of hypoglycemia awareness and metabolic control in patients with T1D, particularly in adults with impaired perception of hypoglycemia symptoms.

Trial registration: ClinicalTrial.gov ID NCT04900636.