Advanced hybrid closed-loop systems (AHCL) systems are the preferred insulin delivery method for people with type 1 diabetes (PwT1D). Time in tight range (TITR) is becoming a new target for glycemic control. The ability of different AHCL systems to achieve an improvement in TITR remains unclear.

Multicenter observational cross-sectional study to analyze the effect on TITR of the three different AHCL systems marketed in Spain: MM780G with SmartGuard (MM780G), Tandem t:slim X2 with Control-IQ (Control-IQ) and Ypsopump with CamAPS FX (CamAPS). PwT1D ≥ 18 yrs and treated with the same AHCL device for at least 3 months were recruited consecutively. The main objective was to analyze the differences in TITR between the three types of AHCL.

A total of 189 patients (female 66.8%) were recruited. Mean age was 42.8 ± 12.8 yrs. (18-72 yrs.) and T1D duration 23.5 ± 11.8 yrs. Time on AHCL automatization was 94.6 ± 7.6%. Overall TITR was 51.7 ± 11.6 % with no between-group differences ( P  = 0.154). Notably, nocturnal TITR was higher with CamAPS (53.6 ± 15.4%, P  = 0.029), compared to MM780G (45.9 ± 17.8%, P  = 0.029) and Control-IQ (50.6 ± 15.4%, P  = 0.029). However, time below range level 1 and 2 was higher among CamAPS group (3.9 ± 2.8% and 0.7 ± 1.0%, respectively; P < 0.001), compared to MM780G (1.6 ± 1.6% and 0.2 ± 0.3%, respectively; P < 0.001) and Control-IQ (2.5 ± 2.0% and 0.5 ± 0.5%, respectively; P < 0.001). HbA1c was higher in MM780G treated patients, compared to both Control-IQ and CamAPS (6.9 ± 0.7% vs. 6.5 ± 0.6%, P  = 0.003).

AHCL systems are useful for achieving TITR >50%, with no differences between treatment groups. However, this study has detected differences in some aspects of glycemic control between the devices used which could have clinical implications.