title: Preliminary evaluation of a new semi-closed-loop insulin therapy system over the prandial period in adult patients with type 1 diabetes: the WP6.0 Diabeloop study.
abstract: There is room for improvement in the algorithms used in closed-loop insulin therapy during the prandial period. This pilot study evaluated the efficacy and safety of the Diabeloop algorithm (model predictive control type) during the postprandial period. This 2-center clinical trial compared interstitial glucose levels over two 5-hour periods (with/without the algorithm) following a calibrated lunch. On the control day, the amount of insulin delivered by the pump was determined according to the patient's usual parameters. On the test day, 50% or 75% of the theoretical bolus required was delivered, while the algorithm, informed of carbohydrate intake, proposed changes to insulin delivery every 15 minutes using modeling to forecast glucose levels. The primary endpoint was percentage of time spent at near normoglycemia (70-180 mg/dl). Twelve patients with type 1 diabetes (9 men, age 35.6 ± 12.7 years, HbA1c 7.3 ± 0.8%) were included. The percentage of time spent in the target range was 84.5 ± 20.8 (test day) versus 69.2 ± 33.9% (control day, P = .11). The percentage of time spent in hypoglycemia < 70 mg/dl was 0.2 ± 0.8 (test) versus 4.4 ± 8.2% (control, P = .18). Interstitial glucose at the end of the test (5 hours) was 127.5 ± 40.1 (test) versus 146 ± 53.5 mg/dl (control, P = .25). The insulin doses did not differ, and no differences were observed between the 50% and 75% boluses. In a semi-closed-loop configuration with manual priming boluses (25% or 50% reduction), the Diabeloop v1 algorithm was as successful as the manual method in determining the prandial bolus, without any exposure to excessive hypoglycemic risk.
authors.affiliation: Department of Endocrinology, Grenoble University Hospital, Grenoble, France.
authors.forename: Marie Aude
authors.initials: MA
authors.lastname: Quemerais
authors.affiliation: University Grenoble Alpes, Grenoble, France CEA, LETI, DTBS, Laboratoire électronique et systèmes pour la santé, Grenoble, France.
authors.forename: Maeva
authors.initials: M
authors.lastname: Doron
authors.affiliation: University Grenoble Alpes, Grenoble, France CEA, LETI, DTBS, Laboratoire électronique et systèmes pour la santé, Grenoble, France.
authors.forename: Florent
authors.initials: F
authors.lastname: Dutrech
authors.affiliation: Department of Diabetology, Toulouse Rangueil University Hospital, Toulouse, France.
authors.forename: Vincent
authors.initials: V
authors.lastname: Melki
authors.affiliation: Department of Diabetes, Sud-Francilien Hospital, Corbeil-Essonnes, France CERITD, Corbeil-Essonnes, France.
authors.forename: Sylvia
authors.initials: S
authors.lastname: Franc
authors.affiliation: University Grenoble Alpes, Grenoble, France CEA, LETI, DTBS, Laboratoire électronique et systèmes pour la santé, Grenoble, France.
authors.forename: Michel
authors.initials: M
authors.lastname: Antonakios
authors.affiliation: Department of Diabetes, Sud-Francilien Hospital, Corbeil-Essonnes, France CERITD, Corbeil-Essonnes, France.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Charpentier
authors.affiliation: Department of Diabetology, Toulouse Rangueil University Hospital, Toulouse, France.
authors.forename: Helene
authors.initials: H
authors.lastname: Hanaire
authors.affiliation: Department of Endocrinology, Grenoble University Hospital, Grenoble, France pybenhamou@chu-grenoble.fr.
authors.forename: Pierre Yves
authors.initials: PY
authors.lastname: Benhamou
mesh_terms: D000328:Adult; D000465:Algorithms; D003922:Diabetes Mellitus, Type 1 / Q000188:drug therapy*; D005260:Female; D006801:Humans; D007003:Hypoglycemia / Q000517:prevention & control; D007004:Hypoglycemic Agents / Q000008:administration & dosage*; D007328:Insulin / Q000008:administration & dosage*; D007332:Insulin Infusion Systems; D008297:Male; D010865:Pilot Projects; D019518:Postprandial Period
chemical_list: D007004:Hypoglycemic Agents; D007328:Insulin
keywords: algorithm; artificial pancreas; closed-loop insulin therapy; prandial bolus; type 1 diabetes mellitus
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