Closed-loop insulin delivery in inpatients with type 2 diabetes: a randomised, parallel-group trial

Hood Thabit,Sara Hartnell,Janet M Allen,Andrea Lake,Malgorzata E Wilinska,Yue Ruan,Mark L Evans,Anthony P Coll,Roman Hovorka

doi:10.1016/s2213-8587(16)30280-7

Abstract

We assessed whether fully closed-loop insulin delivery (the so-called artificial pancreas) is safe and effective compared with standard subcutaneous insulin therapy in patients with type 2 diabetes in the general ward. For this single-centre, open-label, parallel-group, randomised controlled trial, we enrolled patients aged 18 years or older with type 2 diabetes who were receiving insulin therapy. Patients were recruited from general wards at Addenbrooke's Hospital, Cambridge, UK. Participants were randomly assigned (1:1) by a computer-generated minimisation method to receive closed-loop insulin delivery (using a model-predictive control algorithm to direct subcutaneous delivery of rapid-acting insulin analogue without meal-time insulin boluses) or conventional subcutaneous insulin delivery according to local clinical guidelines. The primary outcome was time spent in the target glucose concentration range of 5·6-10·0 mmol/L during the 72 h study period. Analyses were by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT01774565. Between Feb 20, 2015, and March 24, 2016, we enrolled 40 participants, of whom 20 were randomly assigned to the closed-loop intervention group and 20 to the control group. The proportion of time spent in the target glucose range was 59·8% (SD 18·7) in the closed-loop group and 38·1% (16·7) in the control group (difference 21·8% [95% CI 10·4-33·1]; p=0·0004). No episodes of severe hypoglycaemia or hyperglycaemia with ketonaemia occurred in either group. One adverse event unrelated to study devices occurred during the study (gastrointestinal bleed). Closed-loop insulin delivery without meal-time boluses is effective and safe in insulin-treated adults with type 2 diabetes in the general ward. Diabetes UK; European Foundation for the Study of Diabetes; JDRF; National Institute for Health Research Cambridge Biomedical Research Centre; Wellcome Trust.

Highlights

The prevalence of hyperglycaemia in hospital inpatients is increasing and poses a common clinical problem because of the rising prevalence of type 2 diabetes.[1,2] Inpatient hyperglycaemia is a widely recognised marker of poor prognosis and is associated with increased morbidity, mortality, length of stay, and health-care costs.[3,4] Guidelines for management of hyperglycaemia in inpatients outside the critical care setting have been proposed,[5] but implementation is challenging and varied because of increased workload burden on ward staff and fear of hypoglycaemia
We investigated the efficacy and safety of automated closed-loop insulin de livery without meal-time boluses compared with conventional subcutaneous insulin therapy in patients with type 2 diabetes in the general ward
Our results showed a higher proportion of time spent in the target glucose range and reduced glucose variability with closed-loop insulin delivery compared with conventional therapy, without changing the total daily insulin dose or the time spent in hypoglycaemia

Summary

Introduction

The prevalence of hyperglycaemia in hospital inpatients is increasing and poses a common clinical problem because of the rising prevalence of type 2 diabetes.[1,2] Inpatient hyperglycaemia is a widely recognised marker of poor prognosis and is associated with increased morbidity, mortality, length of stay, and health-care costs.[3,4] Guidelines for management of hyperglycaemia in inpatients outside the critical care setting have been proposed,[5] but implementation is challenging and varied because of increased workload burden on ward staff and fear of hypoglycaemia. Development of effective and safe treatments that reduce staff workload in the general ward is needed. Studies of closed-loop insulin delivery at home in patients with type 1 diabetes have shown the safety and feasibility of the approach in improving glycaemic control and reducing the risk of hypoglycaemia.[8,9]

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Results

Conclusion