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Evaluation of a portable ambulatory prototype for automated overnight closed‐loop insulin delivery in young people with type 1 diabetes
Author(s) -
Elleri Daniela,
Allen Janet M,
Biagioni Martina,
Kumareswaran Kavita,
Leelarathna Lalantha,
Caldwell Karen,
Nodale Marianna,
Wilinska Malgorzata E,
Acerini Carlo L,
Dunger David B,
Hovorka Roman
Publication year - 2012
Publication title -
pediatric diabetes
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.678
H-Index - 75
eISSN - 1399-5448
pISSN - 1399-543X
DOI - 10.1111/j.1399-5448.2012.00903.x
Subject(s) - medicine , evening , bedtime , insulin , ambulatory , type 1 diabetes , insulin pump , crossover study , insulin delivery , blood glucose self monitoring , meal , basal insulin , hypoglycemia , diabetes mellitus , artificial pancreas , basal (medicine) , type 2 diabetes , endocrinology , continuous glucose monitoring , placebo , physics , alternative medicine , pathology , astronomy
Objective To evaluate an ambulatory, portable prototype, overnight automated closed‐loop ( CL ) system and to explore optimal time of CL initiation. Methods We performed a randomized crossover study and compared automated overnight glucose control started at the time of an evening‐meal or at bedtime. Eight young people with type 1 diabetes ( T1D ) on insulin pump therapy [M = 4; age = 14.3 (1.7) yr; HbA1c = 8.2 (1.3)%; mean ( SD )] were studied on two occasions at clinical research facility. A standardized self‐selected evening meal [70 (11)g CHO ] and snack [22 (4)g CHO ] accompanied by prandial insulin boluses were given at 18:00 and 21:00 hours, respectively. In random order, automated CL was started at 18:00 or 21:00 hours and ran until 8:00 hours the next day. Basal insulin delivery was automatically adjusted by a model predictive control algorithm based on real‐time continuous glucose monitor readings. Results Overnight plasma glucose levels (between 21:00 and 08:00 hours) were within the target range (71–145 mg/dL) for 82 (59, 98)% of time when CL started at 18:00 hours and 64 (48, 70)% when CL started at 21:00 hours [median ( IQR ), p = 0.036]. Time spent above 180 mg/dL [8 (0, 17) vs. 13 (3, 26)%, p = 0.310] or below 70 mg/dL [0 (0,7) vs. 0 (0, 8)%, p = 1.000] did not differ between the two occasions. Mean overnight glucose [121 (14) vs. 137 (13) mg/dL, p = 0.731) was also similar. Overnight insulin infusion rates were comparable [0.8 (0.5, 1.3) vs. 0.8 (0.6, 1.4) U/h, p = 0.263]. No interruptions to CL delivery were observed. Conclusion Automated CL delivery can be applied reliably and safely to control glucose levels overnight in young people with T1D . Tighter glucose levels may be achieved with an earlier time of CL initiation.