The aim of the study was to evaluate the night-time variability (from 00 to 07 a.m.) of insulin requirements in adults with type 1 diabetes (T1D) mellitus treated with Advanced Hybrid Closed-Loop (AHCL) Systems. We retrospectively evaluated 55 adults with T1D (mean age 41±16 years, male 40%, diabetes duration 19.4±11.4 years, BMI 24.1±4.1 kg/m2) with similar glycemic control (GMI 7.0-7.4%). Twenty-two participants were using the Minimed 780G system, 18 the Tandem t:slim X2 with Control-IQ system and 15 the DBLG1 system. Continuous glucose monitoring derived metrics and insulin requirements of 14 consecutive nights were analyzed. Both total and hourly insulin requirements were calculated for each night. The hourly coefficient of variation (CV) of exogenous insulin delivery during night-time was calculated to quantify intraperson variability of insulin requirements in all participants. All participants achieved the recommended mean TIR >70%, mean TBR<4%, and mean CV<36% during the night-time (TIR 73.4±11.1%, TBR 1±2.6%, CV 31.7±7.1%). The trend of glucose was similar in the three groups with a progressive reduction from 00:00 to 06:00. Total and hourly insulin requirement and coefficient of variation of the insulin requirements are shown in Table 1. Insulin requirements decreased during first hours of the night and then increased again from 5 to 7 am, likely due to the so called “dawn effect”. The difference between hourly insulin requirements was statistically significant. Furthermore, we observed a high variability in individual hourly insulin requirements of the night-time. This high intraperson day-to-day variability of hourly insulin requirements during the night is difficult to overcome with conventional therapeutic tools (such as multiple daily injections and insulin pumps). Therefore, our results emphasize the importance of advanced technologies such as closed-loop systems to safely and effectively manage people with T1D.
