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

Diabetes Care. 2018 Oct;41(10):2155-2161. doi: 10.2337/dc18-0771. Epub 2018 Aug 8.

Abstract

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.

Trial registration: ClinicalTrials.gov NCT03195140.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Algorithms
  • Blood Glucose / analysis
  • Blood Glucose Self-Monitoring* / methods
  • Child
  • Cross-Over Studies
  • Diabetes Mellitus, Type 1 / blood
  • Diabetes Mellitus, Type 1 / diagnosis
  • Diabetes Mellitus, Type 1 / drug therapy*
  • Drug Delivery Systems
  • Female
  • Humans
  • Hypoglycemia / blood
  • Hypoglycemia / chemically induced
  • Hypoglycemia / prevention & control*
  • Hypoglycemic Agents / administration & dosage*
  • Insulin / administration & dosage*
  • Insulin Infusion Systems*
  • Male
  • Middle Aged
  • Monitoring, Ambulatory
  • Young Adult

Substances

  • Blood Glucose
  • Hypoglycemic Agents
  • Insulin

Associated data

  • ClinicalTrials.gov/NCT03195140