No abstract

SummaryBackgroundThe achievement of glycaemic control remains challenging for patients with type 1 diabetes. We assessed the effectiveness of day-and-night hybrid closed-loop insulin delivery compared with sensor-augmented pump therapy in people with suboptimally controlled type 1 diabetes aged 6 years and older.MethodsIn this open-label, multicentre, multinational, single-period, parallel randomised controlled trial, participants were recruited from diabetes outpatient clinics at four hospitals in the UK and two centres in the USA. We randomly assigned participants with type 1 diabetes aged 6 years and older treated with insulin pump and with suboptimal glycaemic control (glycated haemoglobin [HbA1c] 7·5–10·0%) to receive either hybrid closed-loop therapy or sensor-augmented pump therapy over 12 weeks of free living. Training on study insulin pump and continuous glucose monitoring took place over a 4-week run-in period. Eligible subjects were randomly assigned using central randomisation software. Allocation to the two study groups was unblinded, and randomisation was stratified within centre by low (<8·5%) or high (≥8·5%) HbA1c. The primary endpoint was the proportion of time that glucose concentration was within the target range of 3·9–10·0 mmol/L at 12 weeks post randomisation. Analyses of primary outcome and safety measures were done in all randomised patients. The trial is registered with ClinicalTrials.gov, number NCT02523131, and is closed to accrual.FindingsFrom May 12, 2016, to Nov 17, 2017, 114 individuals were screened, and 86 eligible patients were randomly assigned to receive hybrid closed-loop therapy (n=46) or sensor-augmented pump therapy (n=40; control group). The proportion of time that glucose concentration was within the target range was significantly higher in the closed-loop group (65%, SD 8) compared with the control group (54%, SD 9; mean difference in change 10·8 percentage points, 95% CI 8·2 to 13·5; p<0·0001). In the closed-loop group, HbA1c was reduced from a screening value of 8·3% (SD 0·6) to 8·0% (SD 0·6) after the 4-week run-in, and to 7·4% (SD 0·6) after the 12-week intervention period. In the control group, the HbA1c values were 8·2% (SD 0·5) at screening, 7·8% (SD 0·6) after run-in, and 7·7% (SD 0·5) after intervention; reductions in HbA1c percentages were significantly greater in the closed-loop group compared with the control group (mean difference in change 0·36%, 95% CI 0·19 to 0·53; p<0·0001). The time spent with glucose concentrations below 3·9 mmol/L (mean difference in change −0·83 percentage points, −1·40 to −0·16; p=0·0013) and above 10·0 mmol/L (mean difference in change −10·3 percentage points, −13·2 to −7·5; p<0·0001) was shorter in the closed-loop group than the control group. The coefficient of variation of sensor-measured glucose was not different between interventions (mean difference in change −0·4%, 95% CI −1·4% to 0·7%; p=0·50). Similarly, total daily insulin dose was not different (mean difference in change 0·031 U/kg per day, 95% CI −0·005 to 0·067; p=0·09...

ObjectiveTo explore the experiences of adolescents with type 1 diabetes mellitus (T1DM) and their parents taking part in an overnight closed loop study at home, using qualitative and quantitative research methods.Research design and methodsAdolescents aged 12–18 years on insulin pump therapy were recruited to a pilot closed loop study in the home setting. Following training on the use of a study insulin pump and continuous glucose monitoring (CGM), participants were randomized to receive either real-time CGM combined with overnight closed loop or real-time CGM alone followed by the alternative treatment for an additional 21 days with a 2–3-week washout period in between study arms. Semistructured interviews were performed to explore participants’ perceptions of the impact of the closed loop technology. At study entry and again at the end of each 21-day crossover arm of the trial, participants completed the Diabetes Technology Questionnaire (DTQ) and Hypoglycemia Fear Survey (HFS; also completed by parents).Results15 adolescents and 13 parents were interviewed. Key positive themes included reassurance/peace of mind, confidence, ‘time off’ from diabetes demands, safety, and improved diabetes control. Key negative themes included difficulties with calibration, alarms, and size of the devices. DTQ results reflected these findings. HFS scores were mixed.ConclusionsClosed loop insulin delivery represents cutting-edge technology in the treatment of T1DM. Results indicate that the psychological and physical benefits of the closed loop system outweighed the practical challenges reported. Further research from longitudinal studies is required to determine the long-term psychosocial benefit of the closed loop technology.