Safety of user-initiated intensification of insulin delivery using Cambridge hybrid closed-loop algorithm.
Author
Ware, JuliaWilinska, Malgorzata E
Ruan, Yue
Allen, Janet M
Boughton, Charlotte K
Hartnell, Sara
Bally, Lia
de Beaufort, Carine
Besser, Rachel E J
Campbell, Fiona M
Draxlbauer, Katharine
Elleri, Daniela
Evans, Mark L
Fröhlich-Reiterer, Elke
Ghatak, Atrayee
Hofer, Sabine E
Kapellen, Thomas M
Leelarathna, Lalantha
Mader, Julia K
Mubita, Womba M
Narendran, Parth
Poettler, Tina
Rami-Merhar, Birgit
Tauschmann, Martin
Randell, Tabitha
Thabit, Hood
Thankamony, Ajay
Trevelyan, Nicola
Hovorka, Roman
Publication date
2022-12-08
Metadata
Show full item recordAbstract
Objective: Many hybrid closed-loop (HCL) systems struggle to manage unusually high glucose levels as experienced with intercurrent illness or pre-menstrually. Manual correction boluses may be needed, increasing hypoglycemia risk with overcorrection. The Cambridge HCL system includes a user-initiated algorithm intensification mode ("Boost"), activation of which increases automated insulin delivery by approximately 35%, while remaining glucose-responsive. In this analysis, we assessed the safety of "Boost" mode. Methods: We retrospectively analyzed data from closed-loop studies involving young children (1-7 years, n = 24), children and adolescents (10-17 years, n = 19), adults (≥24 years, n = 13), and older adults (≥60 years, n = 20) with type 1 diabetes. Outcomes were calculated per participant for days with ≥30 minutes of "Boost" use versus days with no "Boost" use. Participants with <10 "Boost" days were excluded. The main outcome was time spent in hypoglycemia <70 and <54 mg/dL. Results: Eight weeks of data for 76 participants were analyzed. There was no difference in time spent <70 and <54 mg/dL between "Boost" days and "non-Boost" days; mean difference: -0.10% (95% confidence interval [CI] -0.28 to 0.07; P = .249) time <70 mg/dL, and 0.03 (-0.04 to 0.09; P = .416) time < 54 mg/dL. Time in significant hyperglycemia >300 mg/dL was 1.39 percentage points (1.01 to 1.77; P < .001) higher on "Boost" days, with higher mean glucose and lower time in target range (P < .001). Conclusions: Use of an algorithm intensification mode in HCL therapy is safe across all age groups with type 1 diabetes. The higher time in hyperglycemia observed on "Boost" days suggests that users are more likely to use algorithm intensification on days with extreme hyperglycemic excursions.Citation
Ware J, Wilinska ME, Ruan Y, Allen JM, Boughton CK, Hartnell S, Bally L, de Beaufort C, Besser REJ, Campbell FM, Draxlbauer K, Elleri D, Evans ML, Fröhlich-Reiterer E, Ghatak A, Hofer SE, Kapellen TM, Leelarathna L, Mader JK, Mubita WM, Narendran P, Poettler T, Rami-Merhar B, Tauschmann M, Randell T, Thabit H, Thankamony A, Trevelyan N, Hovorka R. Safety of User-Initiated Intensification of Insulin Delivery Using Cambridge Hybrid Closed-Loop Algorithm. J Diabetes Sci Technol. 2024 Jul;18(4):882-888. doi: 10.1177/19322968221141924. Epub 2022 Dec 8.Type
ArticleAdditional Links
https://journals.sagepub.com/home/dstPMID
36475908Publisher
SAGE Publicationsae974a485f413a2113503eed53cd6c53
10.1177/19322968221141924