Predictive Low-Glucose Suspend Reduces Hypoglycemia in Adults, Adolescents, and Children With Type 1 Diabetes in an At-Home Randomized Crossover Study: Results of the PROLOG Trial

• DOI: 10.2337/dc18-0771
• Publication Date: 2018-08-08T19:24:23Z
• Authors: Gregory P. Forlenza; Zoey Li; Bruce A. Buckingham; Jordan E. Pinsker; Eda Cengiz; R. Paul Wadwa; Laya Ekhlaspour; Mei Mei Church; Stuart A. Weinzimer; Emily Jost; Tatiana Marcal; Camille Andre; Lori Carria; Vance Swanson; John W. Lum; Craig Kollman; William Woodall; Roy W. Beck
• Keywords: Adult; Blood Glucose; Male; Cross-Over Studies; Adolescent; Blood Glucose Self-Monitoring; Monitoring, Ambulatory; Middle Aged; Hypoglycemia; 3. Good health; Young Adult; 03 medical and health sciences; Diabetes Mellitus, Type 1; Drug Delivery Systems; Insulin Infusion Systems; 0302 clinical medicine; Humans; Hypoglycemic Agents; Insulin; Female; Child; Algorithms; Aged

OBJECTIVE This study evaluated a new insulin delivery system designed to reduce insulin delivery when trends in continuous glucose monitoring (CGM) glucose concentrations predict future hypoglycemia.

RESEARCH DESIGN AND METHODS Individuals with type 1 diabetes (n = 103, age 6–72 years, mean HbA1c 7.3% [56 mmol/mol]) participated in a 6-week randomized crossover trial to evaluate the efficacy and safety of a Tandem Diabetes Care t:slim X2 pump with Basal-IQ integrated with a Dexcom G5 sensor and a predictive low-glucose suspend algorithm (PLGS) compared with sensor-augmented pump (SAP) therapy. The primary outcome was CGM-measured time <70 mg/dL.

RESULTS Both study periods were completed by 99% of participants; median CGM usage exceeded 90% in both arms. Median time <70 mg/dL was reduced from 3.6% at baseline to 2.6% during the 3-week period in the PLGS arm compared with 3.2% in the SAP arm (difference [PLGS − SAP] = −0.8%, 95% CI −1.1 to −0.5, P < 0.001). The corresponding mean values were 4.4%, 3.1%, and 4.5%, respectively, represent-ing a 31% reduction in the time <70 mg/dL with PLGS. There was no increase in mean glucose concentration (159 vs. 159 mg/dL, P = 0.40) or percentage of time spent >180 mg/dL (32% vs. 33%, P = 0.12). One severe hypoglycemic event occurred in the SAP arm and none in the PLGS arm. Mean pump suspension time was 104 min/day.

CONCLUSIONS The Tandem Diabetes Care Basal-IQ PLGS system significantly reduced hypoglycemia without rebound hyperglycemia, indicating that the system can benefit adults and youth with type 1 diabetes in improving glycemic control.