Effect of 6 months hybrid closed-loop insulin delivery in young people with type 1 diabetes: a randomised controlled trial protocol.

INTRODUCTION: Automated insulin delivery (also known as closed loop, or artificial pancreas) has shown potential to improve glycaemic control and quality of life in people with type 1 diabetes (T1D). Automated insulin delivery devices incorporate an insulin pump with continuous glucose monitoring(CGM) and an algorithm, and adjust insulin in real time. This study aims to establish the safety and efficacy of a hybrid closed-loop (HCL) system in a long-term outpatient trial in people with T1D aged 12 -<25 years of age, and compare outcomes with standard therapy for T1D as used in the contemporary community. METHODS AND ANALYSIS: This is an open-label, multicentre, 6-month, randomised controlled home trial to test the MiniMed Medtronic 670G system (HCL) in people with T1D aged 12 -<25 years, and compare it to standard care (multiple daily injections or continuous subcutaneous insulin infusion (CSII), with or without CGM). Following a run-in period including diabetes and carbohydrate counting education, dosage optimisation and baseline glucose control data collection, participants are randomised to either HCL or to continue on their current treatment regimen. The primary aim of the study is to compare the proportion of time spent in target sensor glucose range (3.9-10.0 mmol/L) on HCL versus standard therapy. Secondary aims include a range of glucose control parameters, psychosocial measures, health economic measures, biomarker status, user/technology interactions and healthcare professional expectations. Analysis will be intention to treat. A study in adults with an aligned design is being conducted in parallel to this trial. ETHICS AND DISSEMINATION: Ethics committee permissions were gained from respective institutional review boards. The findings of the study will provide high-quality evidence on the role of HCL in clinical practice.

Effect of 6 months of hybrid closed-loop insulin delivery in adults with type 1 diabetes: a randomised controlled trial protocol.

INTRODUCTION: Manual determination of insulin dosing largely fails to optimise glucose control in type 1 diabetes. Automated insulin delivery via closed-loop systems has improved glucose control in short-term studies. The objective of the present study is to determine the effectiveness of 6 months' closed-loop compared with manually determined insulin dosing on time-in-target glucose range in adults with type 1 diabetes. METHODS AND ANALYSIS: This open-label, seven-centre, randomised controlled parallel group clinical trial will compare home-based hybrid closed-loop versus standard diabetes therapy in Australia. Adults aged ≥25 years with type 1 diabetes using intensive insulin therapy (via multiple daily injections or insulin pump, total enrolment target n=120) will undertake a run-in period including diabetes and carbohydrate-counting education, clinical optimisation and baseline data collection. Participants will then be randomised 1:1 either to 26 weeks of MiniMed 670G hybrid closed-loop system therapy (Medtronic, Northridge, CA, USA) or continuation of their current diabetes therapy. The hybrid closed-loop system delivers insulin automatically to address basal requirements and correct to target glucose level, while bolus doses for meals require user initiation and carbohydrate estimation. Analysis will be intention to treat, with the primary outcome time in continuous glucose monitoring (CGM) target range (3.9-10.0 mmol/L) during the final 3 weeks of intervention. Secondary outcomes include: other CGM parameters, HbA1c, severe hypoglycaemia, psychosocial well-being, sleep, cognition, electrocardiography, costs, quality of life, biomarkers of vascular health and hybrid closed-loop system performance. Semistructured interviews will assess the expectations and experiences of a subgroup of hybrid closed-loop users. ETHICS AND DISSEMINATION: The study has Human Research Ethics Committee approval. The study will be conducted in accordance with the principles of the Declaration of Helsinki and Good Clinical Practice. Results will be disseminated at scientific conferences and via peer-reviewed publications. TRIAL REGISTRATION NUMBER: ACTRN12617000520336; Pre-results.

Prevention of Insulin-Induced Hypoglycemia in Type 1 Diabetes with Predictive Low Glucose Management System.

BACKGROUND: Sensor-augmented pump therapy (SAPT) with algorithms to predict impending low blood glucose and suspend insulin delivery has the potential to reduce hypoglycemia exposure. The aim of this study was to determine whether predictive low glucose management (PLGM) system is effective in preventing insulin-induced hypoglycemia in controlled experiments. METHODS: Two protocols were used to induce hypoglycemia in an in-clinic environment. (A) Insulin bolus: Insulin was administered as a manual bolus through the pump. (B) Increased basal insulin: Hypoglycemia was induced by increasing basal rates overnight to 180%. For both protocols, participants were randomized and studied on 2 separate days; a control day with SAPT alone and an intervention day with SAPT and PLGM activated. The predictive algorithm was programmed to suspend basal insulin infusion when sensor glucose was predicted to be <80 mg/dL in 30 min. The primary outcome was the requirement for hypoglycemia treatment (symptomatic hypoglycemia or plasma glucose <50 mg/dL) and was compared in both control and intervention arms. RESULTS: With insulin bolus, 24/28 participants required hypoglycemia treatment with SAPT alone compared to 5/28 participants when PLGM was activated (P ≤ 0.001). With increased basal rates, all the eight SAPT-alone participants required treatment for hypoglycemia compared to only one with SAPT and PLGM. There was no post pump-suspend hyperglycemia with insulin bolus (P = 0.4) or increased basal rates (P = 0.69) in participants with 2-h pump suspension on intervention days. CONCLUSIONS: SAPT with PLGM reduced the requirement for hypoglycemia treatment following insulin-induced hypoglycemia in an in-clinic setting.

Do all prepubertal years of diabetes duration contribute equally to diabetes complications?

OBJECTIVE: This study was designed to explore the timeline of protection against complications in prepubertal children with diabetes, in particular the effects of diabetes duration before age 5 years. RESEARCH DESIGN AND METHODS: In this study, 193 adolescents with prepubertal diabetes onset were followed longitudinally for retinopathy (early background and clinical) and microalbuminuria (albumin excretion rate >7.5 micro g/min and >20 micro g/min). Multiple logistic regression analysis was used to compare the effect of pre- and postpubertal diabetes duration on the risk of each complication in 90 subjects reassessed as young adults. For the entire cohort, Kaplan-Meier estimates were used to determine time free of each complication, and survival was compared in those diagnosed before and after age 5 years. Accelerated failure time modeling was used to estimate the effect of covariates, including diabetes duration before puberty, on the risk of complications. RESULTS: Prepubertal duration improved the prediction for retinopathy over postpubertal duration alone in the young adults. The survival-free period of retinopathy and microalbuminuria was significantly longer (2-4 years) for those diagnosed before age 5 years compared with those diagnosed after age 5 years. Time to onset of all complications increased progressively with longer diabetes duration before gonadarche. Higher HbA(1c) during adolescence had an independent effect on the risk of retinopathy and microalbuminuria. CONCLUSIONS: Prepubertal diabetes duration remains a significant predictor of retinopathy in young adults. The effect of time on the risk of retinopathy and microalbuminuria is nonuniform, with an increasing delay in the onset of complications in those with longer prepubertal duration. These findings are of major clinical importance when setting targets of glycemic control in young children who are at greatest risk of hypoglycemia.