Correlation between centre size, metabolic variation and mean HbA1c in major paediatric diabetes centres.

AIM: To exploit a relatively homogeneous national health care context and a national diabetes database to address the questions: Is there an optimal clinic/centre size in determining outcomes?; and Can improvement in median centre outcomes be driven by reducing variability in outcome? METHODS: Using the Australasian Diabetes Database Network, data from seven tertiary hospital paediatric diabetes clinics for patients with type one diabetes from Australia were recorded from 6-month uploads: September 2017, March 2018, September 2018 and March 2019. Data from 25 244 patient visits included demographic variables, HbA1C, number of patient visits and insulin regimens. RESULTS: There was no association between centre size and median HbA1C. On the other hand, there was a significant association between or median absolute deviation of HbA1C outcomes and the median HbA1C result between centres. On average every two thirds of a median absolute deviation increase in clinic HbA1C was associated with a 1.0% (10.9 mmol/mol) increase in median clinic HbA1C. CONCLUSIONS: Our data have shown that it is likely difficult for centres to have a low median HbA1C if there is high variance of HbA1C's within centres or within centre treatment groups. This appears to be true regardless of centre size. These findings need to be carefully considered by teams who wish to lower their clinic median HbA1C.

Does insulin pump therapy offer benefits for behaviour, mood, cognition and HbA1c in children and adolescents with type 1 diabetes? A randomised controlled trial with observational follow-up.

AIMS: Improved behaviour, mood, cognition and HbA1c have been reported with short-term use of continuous subcutaneous insulin infusion (CSII) in youth with type 1 diabetes (T1D). We sought to re-examine these findings in a randomised controlled trial (RCT), with longitudinal follow-up. METHODS: RCT of youth aged 7-15 years with T1D, at two tertiary paediatric centres. Participants were randomised to commence CSII or continue multiple daily injections (MDI). Behaviour, mood, cognition and HbA1c were assessed. Primary outcome was difference in parent-reported behaviour (BASC-2) at 4 months. After the 4-month RCT, MDI participants commenced CSII; outcomes were reassessed at +2 years. RESULTS: Participating youth (n=101) were randomised to CSII (n=56) or MDI (n=45). Significant differences favouring CSII were found at 4 months in parent-reported behaviour problems (Cohen's d 0.41 (95% CI 0.004 to 0.795); p=0.048) and HbA1c (mean (95% CI) difference: 7 (2.3 to 11.7) mmol/mol (0.6% (0.2 to 1.0%); p=0.001)). Improvements from baseline were documented in mood and cognitive outcomes in both study groups over the 4-month RCT; however, no between-group differences were evident at 4 months. Sixteen of 76 (21%) participants completing assessments at +2 years had discontinued CSII. In n=60 still using CSII, measurements of behaviour, mood and HbA1c were comparable to baseline. CONCLUSIONS: Parent-reported behaviour problems and HbA1c, but not mood or neurocognitive outcomes, were clinically significantly lower with CSII, relative to MDI, after 4 months. Observational follow-up indicated no impact of treatment modality at +2 years, relative to baseline levels. Taken together, these data indicate that use of CSII alone does not comprehensively benefit neuropsychological outcomes in childhood T1D.

Baricitinib and ß-Cell Function in Patients with New-Onset Type 1 Diabetes.

BACKGROUND: Janus kinase (JAK) inhibitors, including baricitinib, block cytokine signaling and are effective disease-modifying treatments for several autoimmune diseases. Whether baricitinib preserves ß-cell function in type 1 diabetes is unclear. METHODS: In this phase 2, double-blind, randomized, placebo-controlled trial, we assigned patients with type 1 diabetes diagnosed during the previous 100 days to receive baricitinib (4 mg once per day) or matched placebo orally for 48 weeks. The primary outcome was the mean C-peptide level, determined from the area under the concentration-time curve, during a 2-hour mixed-meal tolerance test at week 48. Secondary outcomes included the change from baseline in the glycated hemoglobin level, the daily insulin dose, and measures of glycemic control assessed with the use of continuous glucose monitoring. RESULTS: A total of 91 patients received baricitinib (60 patients) or placebo (31 patients). The median of the mixed-meal-stimulated mean C-peptide level at week 48 was 0.65 nmol per liter per minute (interquartile range, 0.31 to 0.82) in the baricitinib group and 0.43 nmol per liter per minute (interquartile range, 0.13 to 0.63) in the placebo group (P = 0.001). The mean daily insulin dose at 48 weeks was 0.41 U per kilogram of body weight per day (95% confidence interval [CI], 0.35 to 0.48) in the baricitinib group and 0.52 U per kilogram per day (95% CI, 0.44 to 0.60) in the placebo group. The levels of glycated hemoglobin were similar in the two trial groups. However, the mean coefficient of variation of the glucose level at 48 weeks, as measured by continuous glucose monitoring, was 29.6% (95% CI, 27.8 to 31.3) in the baricitinib group and 33.8% (95% CI, 31.5 to 36.2) in the placebo group. The frequency and severity of adverse events were similar in the two trial groups, and no serious adverse events were attributed to baricitinib or placebo. CONCLUSIONS: In patients with type 1 diabetes of recent onset, daily treatment with baricitinib over 48 weeks appeared to preserve ß-cell function as estimated by the mixed-meal-stimulated mean C-peptide level. (Funded by JDRF International and others; BANDIT Australian New Zealand Clinical Trials Registry number, ACTRN12620000239965.).

Socioeconomic representativeness of Australian, Canadian and British cohorts from the paediatric diabetes AdDIT study: comparisons to regional and national data.

BACKGROUND: Given limited data regarding the involvement of disadvantaged groups in paediatric diabetes clinical trials, this study aimed to evaluate the socioeconomic representativeness of participants recruited into a multinational clinical trial in relation to regional and national type 1 diabetes reference populations. METHODS: Retrospective, cross-sectional evaluation of a subset of adolescent type 1 diabetes cardiorenal intervention trial (AdDIT) participants from Australia (n = 144), Canada (n = 312) and the UK (n = 173). Validated national measures of deprivation were used: the Index of Relative Socioeconomic Disadvantage (IRSD) 2016 (Australia), the Material Resources (MR) dimension of the Canadian Marginalisation index 2016 (Canada) and the Index of Multiple Deprivation (IMD) 2015 (UK). Representativeness was assessed by comparing the AdDIT cohort's distribution of deprivation quintiles with that of the local paediatric type 1 diabetes population (regional), and the broader type 1 diabetes population for which the trial's intervention was targeted (national). RESULTS: Recruited study cohorts from each country had higher proportions of participants with higher SES, and significant underrepresentation of lower SES, in relation to their national references. The socioeconomic make-up in Australia mirrored that of the regional population (p = 0.99). For Canada, the 2nd least deprived (p = 0.001) and the most deprived quintiles (p < 0.001) were over- and under-represented relative to the regional reference, while the UK featured higher regional and national SES bias with over-representation and under-representation from the least-deprived and most-deprived quintiles (p < 0.0001). CONCLUSIONS: Significant national differences in trial participation of low SES participants were observed, highlighting limitations in access to clinical research and the importance of reporting sociodemographic representation in diabetes clinical trials. TRIAL REGISTRATION: NCT01581476. Registered on 20 April 2012.

Impact of Missing Data on the Accuracy of Glucose Metrics from Continuous Glucose Monitoring Assessed Over a 2-Week Period.

Objective: To explore the impact of missing data on the accuracy of continuous glucose monitoring (CGM) metrics collected for a 2-week period in a clinical trial. Research Design and Methods: Simulations were conducted to examine the effect of various patterns of missingness on the accuracy of CGM metrics as compared with a "complete" data set. The proportion of missing data, the "block size" in which the data were missing, and the missing mechanism were modified for each "scenario." The degree of agreement between simulated and "true" glycemic measures under each scenario was presented as R2. Results: Under all missing patterns, R2 declined as the proportion of missing data increased, however, as the "block size" of missing data increased, the percentage of missing data had a more pronounced effect on the agreement between measures. For a 14-day CGM data set to be considered representative for percentage time in range (%TIR), at least 70% of CGM data should be available over at least 10 days (R2 > 0.9). Skewed outcome measures, such as percentage time below range and coefficient of variation, were more affected by missing data than the less skewed measures (%TIR, percentage time above range, mean glucose). Conclusions: Both the degree and pattern of missing data impact upon the accuracy of recommended CGM-derived glycemic measures. In planning research, an understanding of patterns of missing data in the study population is required to gauge the likely effects of missing data on outcome accuracy. Trial registration number: Australian New Zealand Clinic Trials Registry ACTRN12616000753459.

Glutamine deamidation does not increase the immunogenicity of C-peptide in people with type 1 diabetes.

Type 1 diabetes (T1D) is a T-cell mediated autoimmune disease in which the insulin-producing beta cells are destroyed. While it is clear that full-length C-peptide, derived from proinsulin, is a major antigen in human T1D it is not clear how and why C-peptide becomes a target of the autoimmune CD4+ T-cell responses in T1D. Neoepitopes formed by the conversion of glutamine (Q) residues to glutamic acid (E) by deamidation are central to the immune pathogenesis of coeliac disease and have been implicated in autoimmune responses in T1D. Here, we asked if the immunogenicity of full-length C-peptide, which comprises four glutamine residues, was enhanced by deamidation, which we mimicked by substituting glutamic acid for glutamine residue. First, we used a panel of 18 well characterized CD4+ T-cell lines specific for epitopes derived from human C-peptide. In all cases, when the substitution fell within the cognate epitope the response was diminished, or in a few cases unchanged. In contrast, when the substitution fell outside the epitope recognized by the TCR responses were unchanged or slightly augmented. Second, we compared CD4+ T-cell proliferation responses, against deamidated and unmodified C-peptide, in the peripheral blood of people with or without T1D using the CFSE-based proliferation assay. While, as reported previously, responses were detected to unmodified C-peptide, no deamidated C-peptide was consistently more stimulatory than native C-peptide. Overall responses were weaker to deamidated C-peptide compared to unmodified C-peptide. Hence, we conclude that deamidated C-peptide does not play a role in beta-cell autoimmunity in people with T1D.

Adolescent ambivalence about diabetes technology-The Janus faces of automated care.

The Janus face metaphor approach highlights that a technology may simultaneously have two opposite faces or properties with unforeseen paradoxes within human-technology interaction. Suboptimal acceptance and clinical outcomes are sometimes seen in adolescents who use diabetes-related technologies. A traditional linear techno-determinist model of technology use would ascribe these unintended outcomes to suboptimal technology, suboptimal patient behavior, or suboptimal outcome measures. This paradigm has demonstratively not been successful at universally improving clinical outcomes over the last two decades. Alternatively, the Janus face metaphor moves away from a linear techno-determinist model and focuses on the dynamic interaction of the human condition and technology. Specifically, it can be used to understand variance in adoption or successful use of diabetes-related technology and to retrospectively understand suboptimal outcomes. The Janus face metaphor also allows for a prospective exploration of potential impacts of diabetes-related technology by patients, families, and their doctors so as to anticipate and minimize potential subsequent tensions.

Decreased occurrence of ketoacidosis and preservation of beta cell function in relatives screened and monitored for type 1 diabetes in Australia and New Zealand.

AIMS: Islet autoantibody screening of infants and young children in the Northern Hemisphere, together with semi-annual metabolic monitoring, is associated with a lower risk of ketoacidosis (DKA) and improved glucose control after diagnosis of clinical (stage 3) type 1 diabetes (T1D). We aimed to determine if similar benefits applied to older Australians and New Zealanders monitored less rigorously. METHODS: DKA occurrence and metabolic control were compared between T1D relatives screened and monitored for T1D and unscreened individuals diagnosed in the general population, ascertained from the Australasian Diabetes Data Network. RESULTS: Between 2005 and 2019, 17,105 relatives (mean (SD) age 15.7 (10.8) years; 52% female) were screened for autoantibodies against insulin, glutamic acid decarboxylase, and insulinoma-associated protein 2. Of these, 652 screened positive to a single and 306 to multiple autoantibody specificities, of whom 201 and 215, respectively, underwent metabolic monitoring. Of 178 relatives diagnosed with stage 3 T1D, 9 (5%) had DKA, 7 of whom had not undertaken metabolic monitoring. The frequency of DKA in the general population was 31%. After correction for age, sex and T1D family history, the frequency of DKA in screened relatives was >80% lower than in the general population. HbA1c and insulin requirements following diagnosis were also lower in screened relatives, consistent with greater beta cell reserve. CONCLUSIONS: T1D autoantibody screening and metabolic monitoring of older children and young adults in Australia and New Zealand, by enabling pre-clinical diagnosis when beta cell reserve is greater, confers protection from DKA. These clinical benefits support ongoing efforts to increase screening activity in the region and should facilitate the application of emerging immunotherapies.

Hybrid closed-loop therapy with a first-generation system increases confidence and independence in diabetes management in youth with type 1 diabetes.

AIM: Hybrid closed-loop (HCL) therapy improves glycaemic control in adolescents with type 1 diabetes; however, little is known about their lived experience using these systems. The aim of this study was to explore the lived experiences of youth with type 1 diabetes using HCL therapy, and their parents, to provide insight into their lived experiences. METHODS: Adolescents and young adults aged 12-25 years, who used Medtronic MiniMed™ 670G HCL system during a 6-month randomised clinical trial, and their parents, were invited to participate in a semi-structured interview at the end of the study. Open-ended questions were used to explore the lived experiences of families using HCL. The interviews were audio-recorded, transcribed and analysed using thematic analysis to determine the main themes. RESULTS: In all, 17 young people with type 1 diabetes mean ± SD age: 17.5 ± 4.2 years, diabetes duration: 11.0 ± 4.9 years and HbA1c 64 ± 9 mmol/mol (8.0 ± 0.8%) and 10 parents were interviewed. Three themes were identified: (1) 'Developing confidence and trust in the system', (2) 'Reduction in anxiety' and (3) 'Issues with device'. They reported a positive experience using HCL, with improvements in glucose levels and increased independence with diabetes management. However, frustration around the number of alarms and notifications associated with the system were also identified as issues. CONCLUSION: Both youth and parents acknowledged the benefits of this first-generation HCL system in improving glycaemic outcomes and in providing flexibility and independence. These lived experiences provide valuable information in the introduction and provision of targeted education with HCL therapy.

Urinary albumin/creatinine ratio tertiles predict risk of diabetic retinopathy progression: a natural history study from the Adolescent Cardio-Renal Intervention Trial (AdDIT) observational cohort.

AIMS/HYPOTHESIS: We hypothesised that adolescents with type 1 diabetes with a urinary albumin/creatinine ratio (ACR) in the upper tertile of the normal range (high ACR) are at greater risk of three-step diabetic retinopathy progression (3DR) independent of glycaemic control. METHODS: This was a prospective observational study in 710 normoalbuminuric adolescents with type 1 diabetes from the non-intervention cohorts of the Adolescent Cardio-Renal Intervention Trial (AdDIT). Participants were classified as 'high ACR' or 'low ACR' (lowest and middle ACR tertiles) using baseline standardised log10 ACR. The primary outcome, 3DR, was determined from centrally graded, standardised two-field retinal photographs. 3DR risk was determined using multivariable Cox regression for the effect of high ACR, with HbA1c, BP, LDL-cholesterol and BMI as covariates; diabetes duration was the time-dependent variable. RESULTS: At baseline mean ± SD age was 14.3 ± 1.6 years and mean ± SD diabetes duration was 7.2 ± 3.3 years. After a median of 3.2 years, 83/710 (12%) had developed 3DR. In multivariable analysis, high ACR (HR 2.1 [1.3, 3.3], p=0.001), higher mean IFCC HbA1c (HR 1.03 [1.01, 1.04], p=0.001) and higher baseline diastolic BP SD score (HR 1.43 [1.08, 1.89], p=0.01) were independently associated with 3DR risk. CONCLUSIONS/INTERPRETATION: High ACR is associated with greater risk of 3DR in adolescents, providing a target for future intervention studies. TRIAL REGISTRATION: isrctn.org ISRCTN91419926.

Universal Subsidized Continuous Glucose Monitoring Funding for Young People With Type 1 Diabetes: Uptake and Outcomes Over 2 Years, a Population-Based Study.

OBJECTIVE: Continuous glucose monitoring (CGM) is increasingly used in type 1 diabetes management; however, funding models vary. This study determined the uptake rate and glycemic outcomes following a change in national health policy to introduce universal subsidized CGM funding for people with type 1 diabetes aged <21 years. RESEARCH DESIGN AND METHODS: Longitudinal data from 12 months before the subsidy until 24 months after were analyzed. Measures and outcomes included age, diabetes duration, HbA1c, episodes of diabetic ketoacidosis and severe hypoglycemia, insulin regimen, CGM uptake, and percentage CGM use. Two data sources were used: the Australasian Diabetes Database Network (ADDN) registry (a prospective diabetes database) and the National Diabetes Service Scheme (NDSS) registry that includes almost all individuals with type 1 diabetes nationally. RESULTS: CGM uptake increased from 5% presubsidy to 79% after 2 years. After CGM introduction, the odds ratio (OR) of achieving the HbA1c target of <7.0% improved at 12 months (OR 2.5, P < 0.001) and was maintained at 24 months (OR 2.3, P < 0.001). The OR for suboptimal glycemic control (HbA1c ≥9.0%) decreased to 0.34 (P < 0.001) at 24 months. Of CGM users, 65% used CGM >75% of time, and had a lower HbA1c at 24 months compared with those with usage <25% (7.8 ± 1.3% vs. 8.6 ± 1.8%, respectively, P < 0.001). Diabetic ketoacidosis was also reduced in this group (incidence rate ratio 0.49, 95% CI 0.33-0.74, P < 0.001). CONCLUSIONS: Following the national subsidy, CGM use was high and associated with sustained improvement in glycemic control. This information will inform economic analyses and future policy and serve as a model of evaluation diabetes technologies.

Effect of a Hybrid Closed-Loop System on Glycemic and Psychosocial Outcomes in Children and Adolescents With Type 1 Diabetes: A Randomized Clinical Trial.

Importance: Hybrid closed-loop (HCL) therapy has improved glycemic control in children and adolescents with type 1 diabetes; however, the efficacy of HCL on glycemic and psychosocial outcomes has not yet been established in a long-term randomized clinical trial. Objective: To determine the percentage of time spent in the target glucose range using HCL vs current conventional therapies of continuous subcutaneous insulin infusion or multiple daily insulin injections with or without continuous glucose monitoring (CGM). Design, Setting, and Participants: This 6-month, multicenter, randomized clinical trial included 172 children and adolescents with type 1 diabetes; patients were recruited between April 18, 2017, and October 4, 2019, in Australia. Data were analyzed from July 25, 2020, to February 26, 2021. Interventions: Eligible participants were randomly assigned to either the control group for conventional therapy (continuous subcutaneous insulin infusion or multiple daily insulin injections with or without CGM) or the intervention group for HCL therapy. Main Outcomes and Measures: The primary outcome was the percentage of time in range (TIR) within a glucose range of 70 to 180 mg/dL, measured by 3-week masked CGM collected at the end of the study in both groups. Secondary outcomes included CGM metrics for hypoglycemia, hyperglycemia, and glycemic variability and psychosocial measures collected by validated questionnaires. Results: A total of 135 patients (mean [SD] age, 15.3 [3.1] years; 76 girls [56%]) were included, with 68 randomized to the control group and 67 to the HCL group. Patients had a mean (SD) diabetes duration of 7.7 (4.3) years and mean hemoglobin A1c of 64 (11) mmol/mol, with 110 participants (81%) receiving continuous subcutaneous insulin infusion and 72 (53%) receiving CGM. In the intention-to-treat analyses, TIR increased from a mean (SD) of 53.1% (13.0%) at baseline to 62.5% (12.0%) at the end of the study in the HCL group and from 54.6% (12.5%) to 56.1% (12.2%) in the control group, with a mean adjusted difference between the 2 groups of 6.7% (95% CI, 2.7%-10.8%; P = .002). Hybrid closed-loop therapy also reduced the time that patients spent in a hypoglycemic (<70 mg/dL) range (difference, -1.9%; 95% CI, -2.5% to -1.3%) and improved glycemic variability (coefficient of variation difference, -5.7%; 95% CI, -10.2% to -0.9%). Hybrid closed-loop therapy was associated with improved diabetes-specific quality of life (difference, 4.4 points; 95% CI, 0.4-8.4 points), with no change in diabetes distress. There were no episodes of severe hypoglycemia or diabetic ketoacidosis in either group. Conclusions and Relevance: In this randomized clinical trial, 6 months of HCL therapy significantly improved glycemic control and quality of life compared with conventional therapy in children and adolescents with type 1 diabetes. Trial Registration: ANZCTR identifier: ACTRN12616000753459.

T cell receptor recognition of hybrid insulin peptides bound to HLA-DQ8.

HLA-DQ8, a genetic risk factor in type I diabetes (T1D), presents hybrid insulin peptides (HIPs) to autoreactive CD4+ T cells. The abundance of spliced peptides binding to HLA-DQ8 and how they are subsequently recognised by the autoreactive T cell repertoire is unknown. Here we report, the HIP (GQVELGGGNAVEVLK), derived from splicing of insulin and islet amyloid polypeptides, generates a preferred peptide-binding motif for HLA-DQ8. HLA-DQ8-HIP tetramer+ T cells from the peripheral blood of a T1D patient are characterised by repeated TRBV5 usage, which matches the TCR bias of CD4+ T cells reactive to the HIP peptide isolated from the pancreatic islets of a patient with T1D. The crystal structure of three TRBV5+ TCR-HLA-DQ8-HIP complexes shows that the TRBV5-encoded TCR ß-chain forms a common landing pad on the HLA-DQ8 molecule. The N- and C-termini of the HIP is recognised predominantly by the TCR α-chain and TCR ß-chain, respectively, in all three TCR ternary complexes. Accordingly, TRBV5 + TCR recognition of HIP peptides might occur via a 'polarised' mechanism, whereby each chain within the αßTCR heterodimer recognises distinct origins of the spliced peptide presented by HLA-DQ8.

Neural differentiation medium for human pluripotent stem cells to model physiological glucose levels in human brain.

Cortical neurospheres (NSPs) derived from human pluripotent stem cells (hPSC), have proven to be a successful platform to investigate human brain development and neuro-related diseases. Currently, many of the standard hPSC neural differentiation media, use concentrations of glucose (approximately 17.5-25 mM) and insulin (approximately 3.2 µM) that are much greater than the physiological concentrations found in the human brain. These culture conditions make it difficult to analyse perturbations of glucose or insulin on neuronal development and differentiation. We established a new hPSC neural differentiation medium that incorporated physiological brain concentrations of glucose (2.5 mM) and significantly reduced insulin levels (0.86 µM). This medium supported hPSC neural induction and formation of cortical NSPs. The revised hPSC neural differentiation medium, may provide an improved platform to model brain development and to investigate neural differentiation signalling pathways impacted by abnormal glucose and insulin levels.