Unsupervised home use of an overnight closed-loop system over 3-4 weeks: a pooled analysis of randomized controlled studies in adults and adolescents with type 1 diabetes.

AIMS: To compare overnight closed-loop and sensor-augmented pump therapy in patients with type 1 diabetes by combining data collected during free-living unsupervised randomized crossover home studies. METHODS: A total of 40 participants with type 1 diabetes, of whom 24 were adults [mean ± standard deviation (s.d.) age 43 ± 12 years and glycated haemoglobin (HbA1c) 8.0 ± 0.9%] and 16 were adolescents (mean ± s.d. age 15.6 ± 3.6 years and HbA1c 8.1 ± 0.8%), underwent two periods of sensor-augmented pump therapy in the home setting, in combination with or without an overnight closed-loop insulin delivery system that uses a model predictive control algorithm to direct insulin delivery. The order of the two interventions was random; each period lasted 4 weeks in adults and 3 weeks in adolescents. The primary outcome was time during which sensor glucose readings were in the target range of 3.9-8.0 mmol/l. RESULTS: The proportion of time when sensor glucose was in the target range (3.9-8.0 mmol/l) overnight (between 24:00 and 08:00 hours) was 18.5% greater during closed-loop insulin delivery than during sensor-augmented therapy (p < 0.001). Closed-loop therapy significantly reduced mean overnight glucose levels by 0.9 mmol/l (p < 0.001), with no difference in glycaemic variability, as measured by the standard deviation of sensor glucose. Time spent above the target range was reduced (p = 0.001), as was time spent in hypoglycaemia (<3.9 mmol/l; p = 0.014) during closed-loop therapy. Lower mean overnight glucose levels during closed-loop therapy were brought about by increased overnight insulin delivery (p < 0.001) without changes to the total daily delivery (p = 0.84). CONCLUSION: Overnight closed-loop insulin therapy at home in adults and adolescents with type 1 diabetes is feasible, showing improvements in glucose control and reducing the risk of nocturnal hypoglycaemia.Juvenile Diabetes Research Foundation (#22-2009-802) and Diabetes UK (BDA07/0003549) with additional support for the Artificial Pancreas work by National Institute of Diabetes and Digestive and Kidney Diseases (1R01DK085621), and National Institute for Health Research Cambridge Biomedical Research Centre. Abbott Diabetes Care supplied continuous glucose delivery devices and sensors and modified devices to facilitate real-time connectivity.This if the final version of the article. It was originally published by Wiley in Diabetes, Obesity and Metabolism at http://onlinelibrary.wiley.com/doi/10.1111/dom.12427/abstrac

Safety, efficacy and glucose turnover of reduced prandial boluses during closed-loop therapy in adolescents with type 1 diabetes: a randomized clinical trial.

AIMS: To evaluate safety, efficacy and glucose turnover during closed-loop with meal announcement using reduced prandial insulin boluses in adolescents with type 1 diabetes (T1D). METHODS: We conducted a randomized crossover study comparing closed-loop therapy with standard prandial insulin boluses versus closed-loop therapy with prandial boluses reduced by 25%. Eight adolescents with T1D [3 males; mean (standard deviation) age 15.9 (1.5) years, glycated haemoglobin 74 (17) mmol/mol; median (interquartile range) total daily dose 0.9 (0.7, 1.1) IU/kg/day] were studied on two 36-h-long visits. In random order, subjects received closed-loop therapy with either standard or reduced insulin boluses administered with main meals (50-80 g carbohydrates) but not with snacks (15-30 g carbohydrates). Stable-label tracer dilution methodology measured total glucose appearance (Ra_total) and glucose disposal (Rd). RESULTS: The median (interquartile range) time spent in target (3.9-10 mmol/l) was similar between the two interventions [74 (66, 84)% vs 80 (65, 96)%; p = 0.87] as was time spent above 10 mmol/l [21.8 (16.3, 33.5)% vs 18.0 (4.1, 34.2)%; p = 0.87] and below 3.9 mmol/l [0 (0, 1.5)% vs 0 (0, 1.8)%; p = 0.88]. Mean plasma glucose was identical during the two interventions [8.4 (0.9) mmol/l; p = 0.98]. Hypoglycaemia occurred once 1.5 h post-meal during closed-loop therapy with standard bolus. Overall insulin delivery was lower with reduced prandial boluses [61.9 (55.2, 75.0) vs 72.5 (63.6, 80.3) IU; p = 0.01] and resulted in lower mean plasma insulin concentration [186 (171, 260) vs 252 (198, 336) pmol/l; p = 0.002]. Lower plasma insulin was also documented overnight [160 (136, 192) vs 191 (133, 252) pmol/l; p = 0.01, pooled nights]. Ra_total was similar [26.3 (21.9, 28.0) vs 25.4 (21.0, 29.2) µmol/kg/min; p = 0.19] during the two interventions as was Rd [25.8 (21.0, 26.9) vs 25.2 (21.2, 28.8) µmol/kg/min; p = 0.46]. CONCLUSIONS: A 25% reduction in prandial boluses during closed-loop therapy maintains similar glucose control in adolescents with T1D whilst lowering overall plasma insulin levels. It remains unclear whether closed-loop therapy with a 25% reduction in prandial boluses would prevent postprandial hypoglycaemia.US National Institute of Diabetes and Digestive and Kidney Diseases (1R01DK085621). Support for the Artificial Pancreas research programme by the JDRF, Diabetes UK, NIHR Cambridge Biomedical Research Centre, and Wellcome Trust Strategic Award (100574/Z/12/Z) is acknowledged.This is the final version of the article. It first appeared from Wiley via http://dx.doi.org/10.1111/dom.1254

Impact of liver fat on the differential partitioning of hepatic triacylglycerol into VLDL subclasses on high and low sugar diets.

Dietary sugars are linked to the development of non-alcoholic fatty liver disease (NAFLD) and dyslipidaemia, but it is unknown if NAFLD itself influences the effects of sugars on plasma lipoproteins. To study this further, men with NAFLD (n=11) and low liver fat 'controls' (n= 14) were fed two iso-energetic diets, high or low in sugars (26% or 6% total energy) for 12 weeks, in a randomised, cross-over design. Fasting plasma lipid and lipoprotein kinetics were measured after each diet by stable isotope trace-labelling. There were significant differences in the production and catabolic rates of VLDL subclasses between men with NAFLD and controls, in response to the high and low sugar diets. Men with NAFLD had higher plasma concentrations of VLDL1-triacylglycerol (TAG) after the high ( P <0.02) and low sugar ( P <0.0002) diets, a lower VLDL1-TAG fractional catabolic rate after the high sugar diet ( P <0.01), and a higher VLDL1-TAG production rate after the low sugar diet ( P <0.01), relative to controls. An effect of the high sugar diet, was to channel hepatic TAG into a higher production of VLDL1-TAG ( P <0.02) in the controls, but in contrast, a higher production of VLDL2-TAG ( P <0.05) in NAFLD. These dietary effects on VLDL subclass kinetics could be explained, in part, by differences in the contribution of fatty acids from intra-hepatic stores, and de novo lipogenesis. This study provides new evidence that liver fat accumulation leads to a differential partitioning of hepatic TAG into large and small VLDL subclasses, in response to high and low intakes of sugars.The work was supported by a UK government grant from the Biological Biotechnology Scientific Research Council (Grant no. BB/G009899/1); University of Surrey PhD scholarship for AM; Medical Research Council (body composition measurements) and infrastructure support from the National Institute of Health Research at the Cambridge Biomedical Research Centre

NAFLD exacerbates the effect of dietary sugar on liver fat and development of an atherogenic lipoprotein phenotype

This is the author accepted manuscript. It is currently under an indefinite embargo pending publication by Springer.${\bf Aims/hypothesis:}$ We aimed to test the hypothesis that the effects of dietary sugar on lipoprotein metabolism are influenced by non-alcoholic fatty liver disease (NAFLD). ${\bf Methods:}$ The effect of two 12 week, iso-energetic diets, high and low in non-milk extrinsic sugars (26% and 6% total energy), matched for macronutrient content, was examined in a randomised, cross-over study in men with NAFLD (n=11) and controls (n= 14). Lipoprotein kinetics and the sources of fatty acids for triacylglycerol (TAG) production were measured using stable isotope tracers. ${\bf Results:}$ Liver fat was higher after the high versus low-sugar diet in both groups (p<0.02), but men with NAFLD showed a relatively greater response than controls (p<0.05). After the high versus low-sugar diet, VLDL1-TAG production rate was higher in the controls (p <0.002) due to a greater contribution from splanchnic fatty acids (p<0.02) and de novo lipogenesis (p <0.002), whereas in NAFLD, VLDL2-TAG production rate was higher (p <0.05), due to a greater contribution from splanchnic fatty acids (p<0.02). There was no difference in the contribution of systemic NEFA to VLDL1 and VLDL2-TAG production rate between diets in either group. Intermediate density lipoprotein (IDL), LDL2 and LDL3-apolipoprotein B production rates and post-heparin hepatic lipase activity were all higher (p<0.05) on the high-sugar diet in NAFLD. ${\bf Conclusions:}$ A high sugar intake promoted a greater accumulation of liver fat in NAFLD than controls and increased VLDL-TAG production in both groups, due mainly to an increased contribution of fatty acids from splanchnic sources, which includes hepatic TAG storage pools. These effects may drive the formation of atherogenic lipoproteins.The work was supported by a UK government grant from the Biological Biotechnology Scientific Research Council (Grant no. BB/G009899/1); University of Surrey PhD scholarship for AM; Medical Research Council (body composition measurements) and infrastructure support from the National Institute of Health Research at the Cambridge Biomedical Research Centre

Overnight closed loop insulin delivery (artificial pancreas) in adults with type 1 diabetes: crossover randomised controlled studies

Objective To compare the safety and efficacy of overnight closed loop delivery of insulin (artificial pancreas) with conventional insulin pump therapy in adults with type 1 diabetes

Home use of closed loop insulin delivery improves overnight glucose control in adults with type 1 diabetes: A four-week multicentre randomised crossover study

This is the author accepted manuscript and will be embargoed until 16/12/14. The final published version can be found here: http://www.thelancet.com/journals/landia/article/PIIS2213-8587(14)70114-7/fulltext#article_upsell.Background: We assessed whether overnight home use of automated closed loop insulin delivery (artificial pancreas) improves glucose control. Methods: We studied 24 adults with type 1 diabetes in a multicentre crossover study design comparing four weeks of overnight closed loop using a model predictive control algorithm to direct insulin delivery, with four weeks of insulin pump therapy in which participants used real-time display of continuous glucose monitoring independent of their pumps as control. Primary outcome was time when glucose was in the target range of 3•9 and 8•0mmol/l between midnight to 07:00. Analyses were by intention to treat. Trial registration ClinicalTrials.gov NCT01440140. Findings: Closed loop was utilised over median 8•3 (interquartile range 6•0, 9•6)hours on 555nights (86%). Proportion of time when overnight glucose was in target range was significantly higher during closed loop compared to control by 13•5% (95% CI, 7•3-19•7; p<0•001). Mean overnight glucose (8•2±0•9 vs. 9•0±1•3mmol/l; p=0•005) and time spent above target (44•3%±11•9 vs. 57•1%±15•6; p=0•001) were significantly lower during closed loop. Time spent below target was low and comparable [1•8%( 0•6, 3•6) vs. 2•1%(0•7, 3•9);p=0•28]. Lower mean overnight glucose was brought about by increased overnight insulin delivery [6•4 (4•5, 8•1) vs. 4•9 (3•7, 6•3)units;p<0•001) without changing the total daily insulin amount [34•5 (29•3, 48•4) vs. 35•4 (29•7, 45•2)units;p=0•32]. No severe hypoglycaemia episodes occurred during control period and two during closed loop not related to algorithm instructions. Interpretation: Unsupervised overnight closed loop at home is feasible and may improve glucose control in adults with type 1 diabetes

Accuracy of Continuous Glucose Monitoring During Three Closed-Loop Home Studies Under Free-Living Conditions.

OBJECTIVES: Closed-loop (CL) systems modulate insulin delivery based on glucose levels measured by a continuous glucose monitor (CGM). Accuracy of the CGM affects CL performance and safety. We evaluated the accuracy of the Freestyle Navigator(®) II CGM (Abbott Diabetes Care, Alameda, CA) during three unsupervised, randomized, open-label, crossover home CL studies. MATERIALS AND METHODS: Paired CGM and capillary glucose values (10,597 pairs) were collected from 57 participants with type 1 diabetes (41 adults [mean±SD age, 39±12 years; mean±SD hemoglobin A1c, 7.9±0.8%] recruited at five centers and 16 adolescents [mean±SD age, 15.6±3.6 years; mean±SD hemoglobin A1c, 8.1±0.8%] recruited at two centers). Numerical accuracy was assessed by absolute relative difference (ARD) and International Organization for Standardization (ISO) 15197:2013 15/15% limits, and clinical accuracy was assessed by Clarke error grid analysis. RESULTS: Total duration of sensor use was 2,002 days (48,052 h). Overall sensor accuracy for the capillary glucose range (1.1-27.8 mmol/L) showed mean±SD and median (interquartile range) ARD of 14.2±15.5% and 10.0% (4.5%, 18.4%), respectively. Lowest mean ARD was observed in the hyperglycemic range (9.8±8.8%). Over 95% of pairs were in combined Clarke error grid Zones A and B (A, 80.1%, B, 16.2%). Overall, 70.0% of the sensor readings satisfied ISO criteria. Mean ARD was consistent (12.3%; 95% of the values fall within ±3.7%) and not different between participants (P=0.06) within the euglycemic and hyperglycemic range, when CL is actively modulating insulin delivery. CONCLUSIONS: Consistent accuracy of the CGM within the euglycemic-hyperglycemic range using the Freestyle Navigator II was observed and supports its use in home CL studies. Our results may contribute toward establishing normative CGM performance criteria for unsupervised home use of CL.Juvenile Diabetes Research Foundation (#22-2009-802), Diabetes UK (BDA07/0003549) and Seventh Framework Programme of the European Union (Grant Agreement number 247138) with additional support for the Artificial Pancreas work by National Institute of Diabetes and Digestive and Kidney Diseases (1R01DK085621), Wellcome Strategic Award (100574/Z/12/Z), and National Institute for Health Research Cambridge Biomedical Research Centre.This is the final version of the article. It first appeared from Mary Ann Liebert via http://dx.doi.org/10.1089/dia.2015.006

Assessing the efficacy, safety and utility of 6-month day-and-night automated closed-loop insulin delivery under free-living conditions compared with insulin pump therapy in children and adolescents with type 1 diabetes: an open-label, multicentre, multinational, single-period, randomised, parallel group study protocol.

INTRODUCTION: Closed-loop systems titrate insulin based on sensor glucose levels, providing novel means to reduce the risk of hypoglycaemia while improving glycaemic control. We will assess effectiveness of 6-month day-and-night closed-loop insulin delivery compared with usual care (conventional or sensor-augmented pump therapy) in children and adolescents with type 1 diabetes. METHODS AND ANALYSIS: The trial adopts an open-label, multicentre, multinational (UK and USA), randomised, single-period, parallel design. Participants (n=130) are children and adolescents (aged ≥6 and 16.7 mmol/L (300 mg/dL), area under the curve of glucose >10.0 mmol/L (180 mg/dL), total, basal and bolus insulin dose, body mass index z-score and blood pressure. Cognitive, emotional and behavioural characteristics of participants and caregivers and their responses to the closed-loop and clinical trial will be assessed. An incremental cost-effectiveness ratio for closed-loop will be estimated. ETHICS AND DISSEMINATION: Cambridge South Research Ethics Committee and Jaeb Center for Health Research Institutional Review Office approved the study. The findings will be disseminated by peer-review publications and conference presentations. TRIAL REGISTRATION NUMBER: NCT02925299; Pre-results

Closed-Loop Insulin Delivery during Pregnancy in Women with Type 1 Diabetes.

BACKGROUND: In patients with type 1 diabetes who are not pregnant, closed-loop (automated) insulin delivery can provide better glycemic control than sensor-augmented pump therapy, but data are lacking on the efficacy, safety, and feasibility of closed-loop therapy during pregnancy. METHODS: We performed an open-label, randomized, crossover study comparing overnight closed-loop therapy with sensor-augmented pump therapy, followed by a continuation phase in which the closed-loop system was used day and night. Sixteen pregnant women with type 1 diabetes completed 4 weeks of closed-loop pump therapy (intervention) and sensor-augmented pump therapy (control) in random order. During the continuation phase, 14 of the participants used the closed-loop system day and night until delivery. The primary outcome was the percentage of time that overnight glucose levels were within the target range (63 to 140 mg per deciliter [3.5 to 7.8 mmol per liter]). RESULTS: The percentage of time that overnight glucose levels were in the target range was higher during closed-loop therapy than during control therapy (74.7% vs. 59.5%; absolute difference, 15.2 percentage points; 95% confidence interval, 6.1 to 24.2; P=0.002). The overnight mean glucose level was lower during closed-loop therapy than during control therapy (119 vs. 133 mg per deciliter [6.6 vs. 7.4 mmol per liter], P=0.009). There were no significant differences between closed-loop and control therapy in the percentage of time in which glucose levels were below the target range (1.3% and 1.9%, respectively; P=0.28), in insulin doses, or in adverse-event rates. During the continuation phase (up to 14.6 additional weeks, including antenatal hospitalizations, labor, and delivery), glucose levels were in the target range 68.7% of the time; the mean glucose level was 126 mg per deciliter (7.0 mmol per liter). No episodes of severe hypoglycemia requiring third-party assistance occurred during either phase. CONCLUSIONS: Overnight closed-loop therapy resulted in better glucose control than sensor-augmented pump therapy in pregnant women with type 1 diabetes. Women receiving day-and-night closed-loop therapy maintained glycemic control during a high proportion of the time in a period that encompassed antenatal hospital admission, labor, and delivery. (Funded by the National Institute for Health Research and others; Current Controlled Trials number, ISRCTN71510001.)