Feasibility of closed-loop insulin delivery in type 2 diabetes: a randomized controlled study

Diabetes Care. 2014;37(5):1198-203. doi: 10.2337/dc13-1030. Epub 2013 Sep 11.

Abstract

Objective: Closed-loop insulin delivery offers a promising treatment option, but to date, it has only been evaluated in type 1 diabetes. Our aim was to evaluate the feasibility of fully closed-loop subcutaneous insulin delivery in insulin-naïve patients with type 2 diabetes.

Research design and methods: Twelve subjects (seven males, age 57.2 years, BMI 30.5 kg/m2) with noninsulin-treated type 2 diabetes (HbA1c 8.4% [68 mmol/mol], diabetes duration 7.6 years) underwent two 24-h visits (closed-loop and control) in a randomized crossover design. During closed-loop visits, the subjects' routine diabetes therapy was replaced with model predictive control algorithm-driven subcutaneous insulin pump delivery based on real-time continuous glucose monitoring. Meals were unannounced, and no additional insulin was administered for carbohydrates consumed. During control visits, the usual diabetes regimen was continued (metformin 92%, sulfonylureas 58%, dipeptidyl peptidase-4 inhibitors 33%). On both visits, subjects consumed matched 50- to 80-g carbohydrate meals and optional 15-g carbohydrate snacks and remained largely sedentary. Plasma glucose measurements evaluated closed-loop performance.

Results: Compared with conventional therapy, 24 h of closed-loop insulin delivery increased overall the median time in target plasma glucose (3.9-8.0 mmol/L) from 24 to 40% (P = 0.016), despite sensor under-reading by a median of 1.2 mmol/L. The benefit of the closed-loop system was more prominent overnight, with greater time in target glucose (median 78 vs. 35%; P = 0.041) and less time in hyperglycemia (22 vs. 65%; P = 0.041). There was no hypoglycemia during either intervention.

Conclusions: A closed-loop system without meal announcement and using subcutaneous insulin delivery in insulin-naïve patients with type 2 diabetes appears feasible and safe. Improvement in postprandial glucose control may require further optimization of system performance.

Publication types

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

MeSH terms

  • Adult
  • Aged
  • Algorithms
  • Blood Glucose / drug effects
  • Blood Glucose / metabolism*
  • Cross-Over Studies
  • Diabetes Mellitus, Type 2 / blood
  • Diabetes Mellitus, Type 2 / drug therapy*
  • Dietary Carbohydrates / pharmacology
  • Dipeptidyl-Peptidase IV Inhibitors / therapeutic use
  • Female
  • Humans
  • Hypoglycemic Agents / administration & dosage
  • Hypoglycemic Agents / therapeutic use
  • Insulin / administration & dosage*
  • Insulin / therapeutic use*
  • Insulin Infusion Systems*
  • Male
  • Metformin / therapeutic use
  • Middle Aged
  • Sulfonylurea Compounds / therapeutic use
  • Treatment Outcome

Substances

  • Blood Glucose
  • Dietary Carbohydrates
  • Dipeptidyl-Peptidase IV Inhibitors
  • Hypoglycemic Agents
  • Insulin
  • Sulfonylurea Compounds
  • Metformin