A Retrospective Real-Life Study to Compare Glycemic Control Between Simplified Meal Size Estimation and Precise Carbohydrates Counting in Type 1 Diabetes Patients Using DBLG1 Hybrid Closed-Loop System.

Objective: Qualitative meal size estimation (QMSE) could be an interesting alternative to precise carbohydrates counting (PCC) for patients equipped with hybrid closed-loop systems (HCL). The aim is to compare postprandial glycemic control following meals declared by QMSE of the DBLG1 system with PCC. Methods: We randomly selected a 20% sample of patients from the commercial database of type 1 diabetes patients equipped with the DBLG1 system in Europe. We assumed that when the carbohydrates (CHO) amount was identical to the predefined average meal value (small, medium, or large meal), the patient used the semiquantitative method, and the corresponding meals were assigned to the QMSE group. The others were assigned to the PCC group. The glucose metrics of the meals were computed during the postprandial period, defined as [tmeal; tmeal + 4 h], provided that there was no other meal during this 4-h period or during the previous 4 h. Results: A total of 1959 patients from seven Western European countries were included (mean HbA1c 7.6% ± 1.2%; mean age 43.9 ± 14.7 years). Overall, 287,000 meals (47%) were declared with PCC and 327,819 (53%) with QMSE and the mean meal size was 47.2 ± 32.5 g and 48.4 ± 28.6 g, respectively. The postprandial TIR was 62.39% ± 30.86% with QMSE and 63.21% ± 30.62% with PCC. The mean TIR difference of 0.81% was statistically significant but not clinically relevant. Time below range (TBR) was low for both methods of declaration (TBR < 70 mg/dL of 1.4% ± 5.0% with QMSE and 1.4% ± 4.8% with PCC). Conclusion: The semi-quantitative CHO declaration achieves similar glycemic results as CHO counting in this retrospective study. This method could help to reduce the burden of diabetes and offers an alternative to patients reluctant to use CHO counting.