Day-to-day variability of insulin requirements in the inpatient setting: observations during fully closed-loop insulin delivery.

OBJECTIVE To characterise variability of exogenous insulin requirements during fully closed-loop insulin delivery in hospitalised patients with type 2 diabetes (T2D) or new-onset hyperglycaemia, and to determine patient-related characteristics associated with higher variability of insulin requirements. RESEARCH DESIGN AND METHODS We retrospectively analysed data from two fully closed-loop inpatient studies involving adults with T2D or new-onset hyperglycaemia requiring insulin therapy. The coefficient of variation quantified day-to-day variability of exogenous insulin requirements during up to 15 days using fully automated closed-loop insulin delivery. RESULTS Data from 535 days in 67 participants were analysed. The coefficient of variation of day-to-day exogenous insulin requirements was 30±16% and was higher between nights than between any daytime period (56±29% overnight [2300-0459] compared with 41±21% in the morning [0500-1059], 39±15% in the afternoon [1100-1659] and 45±19% during the evening [1700-2259]; all p