Sensor-Augmented Insulin Pump with Predictive Low-Glucose Suspend (PLGS): Determining Optimal Settings of Pump and Sensor in a Multicenter Cohort of Patients with Type 1 Diabetes

INTRODUCTION: The use of predictive low-glucose suspend (PLGS) sensor-augmented pumps has been shown to lead to a significant reduction in hypoglycemic episodes in patients with type 1 diabetes (T1D), but their effects on hyperglycemia exposure are heterogeneous. The aim of this study was to determine the settings of the Medtronic 640G system to obtain the optimal balance between occurrence of both hypoglycemia and hyperglycemia. METHODS: The hypo- and hyperglycemia area under the curve (AUC), as well as system settings [hypoglycemic threshold, mean insulin total daily dose (TDD), mean basal insulin percentage, and mean daily duration of PLGS] were collected between 2 and 12 times during 1 year in patients from four university hospital centers. Univariate/multivariate analyses and receiver operating characteristics (ROC) curves were performed to determine factors associated with hyper- and hypoglycemia AUC. RESULTS: A total of 864 observations were analyzed from 110 patients with T1D. Two preselected settings predictive of low hyperglycemia AUC were a basal insulin percentage < 52.0% [sensitivity (Se) = 0.66 and specificity (Sp) = 0.53] and a PLGS duration > 157.5 min/day (Se = 0.47 and Sp = 0.73). The preselected setting predictive of a low hypoglycemia AUC was a PLGS duration ≤ 174.4 min (Se = 0.83 and Sp = 0.51). Between-visit variation of PLGS and TDD was positively correlated (r = 0.61; p < 0.0001). CONCLUSION: The most important Medtronic 640G setting was the mean daily PLGS duration, where a value between 157.5 and 174.4 min/day was associated with the best reduction in both hypo- and hyperglycemia AUC. In this study, we showed that PLGS duration could be indirectly modified through total daily insulin dose adaptation. Trial Registration: This study is registered in clinicaltrials.gov (NCT 03047486).