TY - JOUR
T1 - Safety of User-Initiated Intensification of Insulin Delivery Using Cambridge Hybrid Closed-Loop Algorithm
AU - Ware, Julia
AU - Wilinska, Malgorzata E
AU - Ruan, Yue
AU - Allen, Janet M
AU - Boughton, Charlotte K
AU - Hartnell, Sara
AU - Bally, Lia
AU - de Beaufort, Carine
AU - Besser, Rachel E J
AU - Campbell, Fiona M
AU - Draxlbauer, Katharine
AU - Elleri, Daniela
AU - Evans, Mark L
AU - Fröhlich-Reiterer, Elke
AU - Ghatak, Atrayee
AU - Hofer, Sabine E
AU - Kapellen, Thomas M
AU - Leelarathna, Lalantha
AU - Mader, Julia K
AU - Mubita, Womba M
AU - Narendran, Parth
AU - Poettler, Tina
AU - Rami-Merhar, Birgit
AU - Tauschmann, Martin
AU - Randell, Tabitha
AU - Thabit, Hood
AU - Thankamony, Ajay
AU - Trevelyan, Nicola
AU - Hovorka, Roman
PY - 2022/12/8
Y1 - 2022/12/8
N2 - 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.
AB - 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.
U2 - 10.1177/19322968221141924
DO - 10.1177/19322968221141924
M3 - Article
C2 - 36475908
SN - 1932-2968
SP - 19322968221141924
JO - Journal of Diabetes Science and Technology
JF - Journal of Diabetes Science and Technology
ER -
