Simplified Meal Management in Adults Using an Advanced Hybrid Closed-Loop System

Background: The advanced hybrid closed-loop (AHCL) algorithm combines automated basal rates and corrections yet requires meal announcement for optimal performance, which poses a challenge for some. We aimed to compare glucose control in adults with type 1 diabetes (T1D) using the MiniMed^TM 780G AHCL system, utilizing simplified meal announcement versus precise carbohydrate (CHO) counting. Methods: In a study involving 14 adults with T1D, we evaluated glycemic control during a 13-week “precise phase,” followed by two 3- to 4-week simplified meal announcement phases: “fixed one-step” (preset of one personalized fixed CHO amount) and “multistep” (entry of multiples of one, two, or three of these presets depending on meal size estimate). Results: The mean age was 45.7 – 12.4, and 10 participants were male (71%). Mean baseline HbA1c was 6.8% – 1.2% and time in range (TIR) was 67.5% – 16.7%. Comparing the fixed one-step to the precise study phase, TIR was similar (75.4 – 13% vs. 77.7 – 9%, P = 0.12), and glucose management indicator (GMI) was slightly higher (6.8 – 0.4 vs. 6.6 – 0, P = 0.01). Furthermore, there was less level 1 and 2 hypoglycemia (1.6 – 1% vs. 2.8 – 2%, P = 0.03 and 0.3 – 5% vs. 0.65 – 1%, P = 0.08) but slightly more level 1 and 2 hyperglycemia (17.1 – 8% vs. 15.0 – 7%, P = 0.05 and 5.5 – 5% vs. 3.6 – 3%, P = 0.04). When comparing the multistep with the precise phase, GMI was identical (6.6%) and TIR superior (80.5 – 10% vs. 77.7 – 9%, P = 0.02). Additionally, there was less level 1 hypoglycemia (1.9 – 1% vs. 2.8 – 2%, P = 0.01) and a trend for less level 2 hypoglycemia (0.4 – 0.7% vs. 0.65 – 1%, P = 0.08). Conclusions: A simplified meal announcement strategy for adults using the MiniMed 780G system, relying on three increments of a fixed one-step CHO amount, may offer a way to improve glycemic control and ease self-care. For patients with more limitations, using one fixed one-step CHO amount could be a safe alternative to meeting most consensus glycemic targets.