Capel, Ismael and Rigla, Mercedes and García Sáez, Gema and Rodriguez Herrero, Agustin and Pons, Belén and Subías, David and Garcia Garcia, Fernando and Gallach, María and Aguilar, Montserrat and Pérez Gandía, Carmen and Gómez Aguilera, Enrique J. and Caixàs, Assumpta and Hernando Pérez, María Elena
Artificial pancreas using a personalized rule-based controller achieves overnight normoglycemia in patients with type 1 diabetes.
"Diabetes Technology & Therapeutics", v. 16
Objective: This study assessed the efﬁcacy of a closed-loop (CL) system consisting of a predictive rule-based algorithm
(pRBA) on achieving nocturnal and postprandial normoglycemia in patients with type 1 diabetes mellitus (T1DM). The
algorithm is personalized for each patient’s data using two different strategies to control nocturnal and postprandial periods.
Research Design and Methods: We performed a randomized crossover clinical study in which 10 T1DM patients treated with continuous subcutaneous insulin infusion (CSII) spent two nonconsecutive nights in the research facility: one with their usual CSII pattern (open-loop [OL]) and one controlled by the pRBA (CL). The CL period lasted from 10 p.m. to 10 a.m., including overnight control, and control of breakfast. Venous samples for blood glucose (BG) measurement were collected every 20 min.
Results: Time spent in normoglycemia (BG, 3.9–8.0 mmol/L) during the nocturnal period (12 a.m.–8 a.m.), expressed as
median (interquartile range), increased from 66.6% (8.3–75%) with OL to 95.8% (73–100%) using the CL algorithm (P<0.05).
Median time in hypoglycemia (BG, <3.9 mmol/L) was reduced from 4.2% (0–21%) in the OL night to 0.0% (0.0–0.0%) in the
CL night (P<0.05). Nine hypoglycemic events (<3.9 mmol/L) were recorded with OL compared with one using CL. The
postprandial glycemic excursion was not lower when the CL system was used in comparison with conventional preprandial
bolus: time in target (3.9–10.0 mmol/L) 58.3% (29.1–87.5%) versus 50.0% (50–100%).
Conclusions: A highly precise personalized pRBA obtains nocturnal normoglycemia, without signiﬁcant hypoglycemia, in
T1DM patients. There appears to be no clear beneﬁt of CL over prandial bolus on the postprandial glycemia