758-P: A Randomized Crossover Trial to Compare Automated Insulin Delivery with Carbohydrate Counting or Simplified Qualitative Meal-Size Estimation in Type 1 Diabetes

Abstract

We did a randomized crossover non-inferiority trial to compare 3 weeks of automated insulin delivery with (i) carbohydrate counting and (ii) qualitative meal-size estimation (low, medium, high, or very high carbohydrate (CHO)) in 30 adults with T1D (20/30 females, age 44±17 yrs, A1c 7.4±0.7%) . Low, medium, high, and very high CHO meals were defined as <30 g CHO, 30-60 g CHO, 60-90 g CHO, and >90 g CHO, respectively, and their prandial insulin boluses were calculated as the individualized insulin-to-CHO ratios x 15, 35, 65, and 95, respectively. Closed-loop algorithms were otherwise identical in the two arms. The time in range 3.9-10.0 mmol/L (primary outcome) was 74% (SD 10%) with carbohydrate counting and 71% (11%) with qualitative meal-size estimation; difference -3.6% (95% CI, -0.6% to -6.5%) which crossed the pre-specified non-inferiority margin of 4%. Times <3.9 mmol/L and <3.0 mmol/L were low in both two arms. Automated basal insulin delivery was higher in the qualitative meal-size estimation arm (34.6 vs. 32.6 u/day, p=0.003) . We conclude that non-inferiority of the qualitative meal-size estimation was not confirmed, though this method achieved a high time in range and low time in hypoglycemia. The qualitative meal-size estimation method may benefit from larger prandial boluses and more responsive post-meal automatic basal delivery. Disclosure A.Haidar: Consultant; Eli Lilly and Company, Research Support; ADOCIA, Dexcom, Inc., Eli Lilly and Company, Tandem Diabetes Care, Inc. L.Legault: Advisory Panel; Abbott Diabetes, Insulet Corporation, Novo Nordisk A/S, Other Relationship; Eli Lilly and Company, Research Support; AstraZeneca, Merck & Co., Inc. M.Raffray: None. N.Gouchie-provencher: None. A.Jafar: None. M.Devaux: None. M.Ghanbari: None. R.Rabasa-lhoret: Consultant; HLS Therapeutics Inc., Pfizer Inc., Other Relationship; Abbott Diabetes, AstraZeneca, Boehringer Ingelheim International GmbH, Dexcom, Inc., Eli Lilly and Company, Insulet Corporation, Janssen Pharmaceuticals, Inc., Medtronic, Merck & Co., Inc., Novo Nordisk Canada Inc., Sanofi, Vertex Pharmaceuticals Incorporated, Research Support; Canadian Institutes of Health Research, Cystic Fibrosis Canada, Diabetes Canada, Fondation Francophone pour la Recherche en Diabète (FFRD) , JDRF, National Institutes of Health, Société Francophone du Diabète (SFD) , Speaker's Bureau; Canadian Medical & Surgical Knowledge Translation Research Group (CMS) , CPD Network, Tandem Diabetes Care, Inc. Funding National Institutes of Health (1DP3DK106930-01)

Comment on Haidar et al. A Randomized Crossover Trial to Compare Automated Insulin Delivery (the Artificial Pancreas) With Carbohydrate Counting or Simplified Qualitative Meal-Size Estimation in Type 1 Diabetes. Diabetes Care 2023;46:1372–1378

“…Our interpretation is that, despite a slight deterioration in TIR when using QMSE, to a lesser extent (1%) than the one observed by Haidar et al (1), the overall glucose metrics remained similar without clinically meaningful differences. This qualitative method may reduce diabetes burden and can be proposed to patients reluctant to perform CHO counting.…”

“…Haidar et al (1) report a crossover trial that compares quantitative carbohydrate (CHO) counting with simplified qualitative meal-size estimation (QMSE) in 30 adult patients with type 1 diabetes (T1D) who used an automated insulin delivery system for 3 weeks. They found that the mean (SD) time in the 3.9-10.0 mmol/L range (TIR) was 74.1% (10.0%) with CHO counting and 70.5% (11.2%) with QMSE.…”

A diabetes update

“…It has been suggested that carbohydrate-counting methods to estimate prandial insulin requirements for people with type 1 diabetes might not be necessary and that simplified qualitative meal-size estimation might offer an easier approach to deciding on appropriate meal insulin doses. 14 A study of 30 persons with type 1 diabetes using a closed-loop insulin pump, however, compared two 3-week periods and showed that when the participants crossed over between the two approaches their "time in range" of 70-180 mg/dL was 74.1% with carbohydrate counting, significantly greater than 70.5% with the qualitative method. 14…”

“…14 A study of 30 persons with type 1 diabetes using a closed-loop insulin pump, however, compared two 3-week periods and showed that when the participants crossed over between the two approaches their "time in range" of 70-180 mg/dL was 74.1% with carbohydrate counting, significantly greater than 70.5% with the qualitative method. 14…”