Safety and Efficacy of Sustained Automated Insulin Delivery Compared With Sensor and Pump Therapy in Adults With Type 1 Diabetes at High Risk for Hypoglycemia: A Randomized Controlled Trial

Abstract

Objective: Assess the safety and efficacy of automated insulin delivery (AID) in adults with type 1 diabetes (T1D) at high risk for hypoglycemia.

Research design and methods: Participants were 72 adults with T1D who used an insulin pump with Clarke Hypoglycemia Perception Awareness scale score >3 and/or had severe hypoglycemia during the previous 6 months confirmed by time below range (TBR; defined as sensor glucose [SG] reading <70 mg/dL) of at least 5% during 2 weeks of blinded continuous glucose monitoring (CGM). Parallel-arm, randomized trial (2:1) of AID (Tandem t:slim ×2 with Control-IQ technology) versus CGM and pump therapy for 12 weeks. The primary outcome was TBR change from baseline. Secondary outcomes included time in target range (TIR; 70-180 mg/dL), time above range (TAR), mean SG reading, and time with glucose level <54 mg/dL. An optional 12-week extension with AID was offered to all participants.

Results: Compared with the sensor and pump (S&P), AID resulted in significant reduction of TBR by -3.7% (95% CI -4.8, -2.6), P < 0.001; an 8.6% increase in TIR (95% CI 5.2, 12.1), P < 0.001; and a -5.3% decrease in TAR (95% CI -87.7, -1.8), P = 0.004. Mean SG reading remained similar in the AID and S&P groups. During the 12-week extension, the effects of AID were sustained in the AID group and reproduced in the S&P group. Two severe hypoglycemic episodes occurred using AID.

Conclusions: In adults with T1D at high risk for hypoglycemia, AID reduced the risk for hypoglycemia more than twofold, as quantified by TBR, while improving TIR and reducing hyperglycemia. Hence, AID is strongly recommended for this specific population.

Trial registration: ClinicalTrials.gov NCT04266379.

Graphical abstract

Figure 1

Percentage of time with the SG level <70 mg/dL and in the 70–180 mg/dL target range during the 12-week randomized study. A: Box-and-whisker plot of the percentage of time that the SG level was <70 mg/dL, as measured by CGM, during weekly periods over 12 weeks among participants who were assigned to receive treatment with either AID (red) or S&P (blue). B: Box-and-whisker plot of the percentage of time the SG level was in the 70–180 mg/dL target range, as measured by CGM, during weekly periods over 12 weeks among participants who were assigned to receive treatment with either AID (red) or S&P (blue). The horizontal bars denote the median values, and the lower and upper boundaries of each box indicate the 25th and 75th percentiles, respectively. The dotted lines denote the range of values. The dotted green lines indicate the aimed 4% maximal value of time the SG level should be <70 mg/dL (A) and the aimed 70% minimal value the SG level should be in the 70–180 mg/dL target range (B), according to Battelino et al. (35).