Glucose outcomes of a learning-type artificial pancreas with an unannounced meal in type 1 diabetes. (July 2020)

• Record Type: Journal Article
• Authors: Song, Lulu; Liu, Changqing; Yang, Wenying; Zhang, Jinping; Kong, Xiaomu; Zhang, Bo; Chen, Xiaoping; Wang, Na; Shen, Dong; Li, Zhaoqing; Jin, Xian; Shuai, Ying; Wang, Youqing
• Is Part Of: Computer methods and programs in biomedicine. Volume 191(2020)
• Publication Date: 2020-07
• Subjects: Artificial pancreas -- Closed-loop insulin system -- Learning, Unannounced meal; Medicine -- Computer programs -- Periodicals; Biology -- Computer programs -- Periodicals; Computers -- Periodicals; Medicine -- Periodicals; Médecine -- Logiciels -- Périodiques; Biologie -- Logiciels -- Périodiques; Biology -- Computer programs; Medicine -- Computer programs; Periodicals; Electronic journals; 610.28
• DOI: 10.1016/j.cmpb.2020.105416
• Languages: English
• ISSNs: 0169-2607

Abstract

Highlights: Based on learning-type model predictive control algorithm the closed-loop insulin delivery system achieved good glycemic glucose control with an unannounced meal in T1D and did not increase the risk of hypoglycemia. Efficiency of this system was robust that it was not disturbed by alcohol consumption or moderate exercise. Abstract: Background and Objectives: Glycemic control with unannounced meals is the major challenge for artificial pancreas. In this study, we described the performance and safety of learning-type model predictive control (L-MPC) for artificial pancreas challenged by an unannounced meal in type 1 diabetes (T1D). Methods: This closed-loop (CL) system was tested in 29 T1D patients at one site in a 4 h inpatient open-label study. Participants used an L-MPC CL system for 6 days after 2-day system identification using open-loop (OL) insulin system. During the CL period, the L-MPC system was started from 8:00 am to noon each day. At 9:00 am, each participant consumed 50 g of carbohydrates with no prandial insulin bolus. At 9:30 am on CL-Day 4 or CL-Day 6, participants rode bicycles for 20 minutes or drank 50 ml of beer, in a random order. Results: As the primary outcome, TIR on CL-Day 3 was 65.2±23.3%, which was 9.8 points higher (95% CI 1.8 to 17.8; P = 0.019) than that on CL-Day 1. The time of glucose >10 mmol/L was decreased by 11.0% (95% CI -18.7 to 3.3; P = 0.007), and mean glucose level was decreased by 1.1 mmol/L (95% CI -1.1 to 0.5; P = 0.000). The total daily insulin dosage showed no significant difference (-0.1U, 95% CI -1.34 to 1.32; P = 0.982). Compared with OL-Day1 with a postprandial bolus, the TIR was increased by 13.7 points (95% CI 1.4 to 26.0; P = 0.030), the time of glucose >10 mmol/L and the mean glucose level were also decreased. Compared with the exercise day (CL-Day E, 62.0 ± 23.3%; P = 0.347) or alcohol day (CL-Day A, 64.0 ± 23.6%; P = 0.756), there was no statistically significant difference in terms of TIR, time of glucose >10 mmol/L and mean glucose level. No severe hypoglycemic events occurred and hypoglycemic episodes were not increased by using closed-loop insulin system. Conclusion: The L-MPC CL insulin system achieved good glycemic control challenged by an unannounced meal.