Islet transplantation outcomes in type 1 diabetes and transplantation of HLA-DQ8/DR4: results of a single-centre retrospective cohort in Canada.

Background: In solid organ transplantation, HLA matching between donor and recipient is associated with superior outcomes. In islet transplantation, an intervention for Type 1 diabetes, HLA matching between donor and recipient is not performed as part of allocation. Susceptibility to Type 1 diabetes is associated with the presence of certain HLA types. This study was conducted to determine the impact of these susceptibility antigens on islet allograft survival. Methods: This is a single-centre retrospective cohort study. This cohort of transplant recipients (n = 268) received islets from 661 donor pancreases between March 11th, 1999 and August 29th, 2018 at the University of Alberta Hospital (Edmonton, AB, Canada). The frequency of the Type 1 diabetes susceptibility HLA antigens (HLA-A24, -B39, -DQ8, -DQ2 and-DQ2-DQA1∗05) in recipients and donors were determined. Recipient and donor HLA antigens were examined in relation to time to first C-peptide negative status/graft failure or last observation point. Taking into account multiple transplants per patient, we fitted a Gaussian frailty survival analysis model with baseline hazard function stratified by transplant number, adjusted for cumulative islet dose and other confounders. Findings: Across all transplants recipients of donors positive for HLA-DQ8 had significantly better graft survival (adjusted HRs 0.33 95% CI 0.17-0.66; p = 0.002). At first transplant only, donors positive for HLA-DQ2-DQA1∗05 had inferior graft survival (adjusted HR 1.96 95% CI 1.10-3.46); p = 0.02), although this was not significant in the frailty analysis taking multiple transplants into account (adjusted HR 1.46 95% CI 0.77-2.78; p = 0.25). Other HLA antigens were not associated with graft survival after adjustment for confounders. Interpretation: Our findings suggest islet transplantation from HLA-DQ8 donors is associated with superior graft outcomes. A donor positive for HLA-DQ2-DQA1∗05 at first transplant was associated with inferior graft survival but not when taking into account multiple transplants per recipient. The relevance of HLA-antigens on organ allocation needs further evaluation and inclusion in islet transplant registries and additional observational and interventional studies to evaluate the role of HLA-DQ8 in islet graft survival are required. Funding: None.

Insulin independence following islet transplantation improves long-term metabolic outcomes.

AIMS: Pancreatic islet allotransplantation is an effective therapy for type 1 diabetes mellitus, restoring glycaemic control and hypoglycaemic awareness in patients with recurrent severe hypoglycaemia. Insulin independence following transplant is being increasingly reported; however, this is not a primary endpoint in the UK. Having surpassed 10 years of islet transplantation in Scotland, we aimed to evaluate the impact of insulin independence following transplant on metabolic outcomes and graft survival. METHODS: We conducted a retrospective analysis on data collected prospectively between 2011 and 2022. Patients who underwent islet transplantation in Scotland up to the 31st January 2020 were included. Primary endpoint was graft survival (stimulated C-peptide >50 pmol/L). Secondary endpoints included GOLD score, HbA1c, C-peptide and insulin requirement. Outcomes were compared between patients who achieved insulin independence at any point following transplant versus those who did not. RESULTS: 60 patients were included. 74.5% experienced >50 severe hypoglycaemic episodes in the year preceding transplant. There was a 55.0% decrease in insulin requirement following transplant and 30.0% achieved insulin independence. Mean graft survival time was 9.0 years (95% CI 7.2-10.9) in patients who achieved insulin independence versus 4.4 years (95% CI 3.4-5.3) in patients who did not. Insulin independence was associated with significantly improved graft function, glycaemic control and hypoglycaemic awareness at 1 year. CONCLUSIONS: This is the largest UK single-centre study on islet transplant to date. Our findings demonstrate significantly improved outcomes in patients who achieved insulin independence following islet transplantation.

Ultrasound-guided hepatic portal vein injection is not a reproducible technique for delivery of cell therapies to the liver in mice.

AIMS: Our aim was to determine if ultrasound-guided HPV injection in mice would provide reproducible and reliable results, as is currently obtained via open laparotomy techniques, and offer a surgical refinement to emulate islet transplantation in humans. METHODS: Fluorescent-polymer microparticles (20 µm) were injected (27G-needle) into the HPV via open laparotomy (n = 4) or under ultrasound-guidance (n = 4) using an MX550D-transducer with a Vevo3100-scanner (FUJIFILM VisualSonics, Inc.). Mice were culled 24-h post injection; organs were frozen, step sectioned (10 µm-slices) and 10 sections/mouse (50 µm-spacing) were quantified for microparticles in the liver and other organs by fluorescent microscopy. RESULTS: Murine HPV injection, via open laparotomy-route, resulted in widespread distribution of microparticles in the liver, lungs and spleen; ultrasound-guided injection resulted in reduced microparticle delivery (p < 0.0001) and microparticle clustering in distinct areas of the liver at the site of needle penetration, with very few/no microparticles being seen in lung and spleen tissues, hypothesised to be due to flow into the body cavity: liver median (interquartile range) 4.15 (0.00-4.15) versus 0.00 (0.00-0.00) particle-count mm-2 , respectively. CONCLUSIONS: Ultrasound-guided injection results in microparticle clustering in the liver, with an overall reduction in microparticle number when compared to open laparotomy HPV injection, and high variability in microparticle-counts detected between mice. Ultrasound-guided injection is not currently a technique that can replace open laparotomy HPV of islet transplantation in mice.

Beta-cell death and dysfunction drives hyperglycaemia in organ donors.

BACKGROUND: Donor hyperglycaemia following brain death has been attributed to reversible insulin resistance. However, our islet and pancreas transplant data suggest that other mechanisms may be predominant. We aimed to determine the relationships between donor insulin use and markers of beta-cell death and beta-cell function in pancreas donors after brain death. METHODS: In pancreas donors after brain death, we compared clinical and biochemical data in 'insulin-treated' and 'not insulin-treated donors' (IT vs. not-IT). We measured plasma glucose, C-peptide and levels of circulating unmethylated insulin gene promoter cell-free DNA (INS-cfDNA) and microRNA-375 (miR-375), as measures of beta-cell death. Relationships between markers of beta-cell death and islet isolation outcomes and post-transplant function were also evaluated. RESULTS: Of 92 pancreas donors, 40 (43%) required insulin. Glycaemic control and beta-cell function were significantly poorer in IT donors versus not-IT donors [median (IQR) peak glucose: 8 (7-11) vs. 6 (6-8) mmol/L, p = .016; C-peptide: 3280 (3159-3386) vs. 3195 (2868-3386) pmol/L, p = .046]. IT donors had significantly higher levels of INS-cfDNA [35 (18-52) vs. 30 (8-51) copies/ml, p = .035] and miR-375 [1.050 (0.19-1.95) vs. 0.73 (0.32-1.10) copies/nl, p = .05]. Circulating donor miR-375 was highly predictive of recipient islet graft failure at 3 months [adjusted receiver operator curve (SE) = 0.813 (0.149)]. CONCLUSIONS: In pancreas donors, hyperglycaemia requiring IT is strongly associated with beta-cell death. This provides an explanation for the relationship of donor IT with post-transplant beta-cell dysfunction in transplant recipients.

Associations between glucagon prescribing, hospital admissions for hypoglycaemia and continuous glucose monitoring metrics in adults with type 1 diabetes.

AIMS: To assess features associated with glucagon prescribing and hospital admissions with hypoglycaemia in type one diabetes. METHODS: Observational study of 4462 adults. Outcome measures were features associated with glucagon prescriptions and predictors of hospital admissions with hypoglycaemia and high levels of glucagon prescribing. RESULTS: 74 % did not collect any glucagon prescriptions and 2.7 % collected >6 over 3.5 years. Hospital admission with hypoglycaemia (P = 0.032), impaired awareness (P = 0.049) and female sex (P < 0.001) were associated with glucagon collection. More frequent prescribing of glucagon was associated with diabetes duration (P < 0.001) and socioeconomic deprivation (P < 0.001). Higher average glucose (P = 0.047), higher time above 13.9 mM (P = 0.008) and higher SD (P = 0.002) were associated with glucagon prescribing. Diabetes duration (P < 0.001) and HbA1c (P < 0.001) were higher in people with hospitalised hypoglycaemia. Higher time above 13.9 mM (P = 0.004) and SD glucose (P < 0.001) were most clearly associated with hospitalised hypoglycaemia. CONCLUSIONS: A minority of people with type 1 diabetes have access to glucagon suggesting more could be done to better target this treatment. Individuals with risk factors and those with frequent glucagon prescriptions should be identified for interventions known to reduce hypoglycaemia.

Changes in continuous glucose monitoring metrics and predictors of improvement 12 months after conversion from Freestyle Libre to Freestyle Libre 2.

AIMS: We sought to assess whether conversion from Freestyle Libre to Freestyle Libre 2 (with low and high glucose alert functions) was associated with improved glucose metrics. RESEARCH DESIGN AND METHODS: A prospective observational study to assess changes in CGM metrics in 672 adults with type 1 diabetes when converting to Freestyle Libre 2. Secondary outcomes included predictors of reduction in time below range (TBR) and increase in time in range (TIR). RESULTS: TBR fell by a median of 1.0% (IQR -2.7 to 0.3, p < 0.001) after 12 months and TIR decreased by 1.0% (-8.7 to 6.0, p = 0.004). TIR did not fall in people using high glucose alerts (p = 0.353). Average duration of low glucose events (<3.9 mmoL/L) fell by 10 min (-46 to 18, p < 0.001). Significant improvements in TIR (p = 0.029) and time above 13.9 mM (p = 0.002) were observed in those using high glucose alerts. Alert threshold settings were not associated with glycaemic response; however, low alert use was independently associated with a fall in TBR of ≥0.5% (HR 1.9 [95% CI 1.2-3.1], p = 0.009) and high alert use was independently associated with a rise in TIR of ≥5% (HR 1.6 [95% CI 1.0-2.5], p = 0.043) at 12 months. CONCLUSIONS: Conversion to Freestyle Libre 2 was associated with significant improvements in low glucose metrics. Alert function users were more likely to see improvements across all CGM metrics. Challenges remain in encouraging alert use, helping users set optimal alert thresholds and optimizing response to alerts.

Non-invasive imaging of functional pancreatic islet beta-cell mass in people with type 1 diabetes mellitus.

AIMS: To investigate whether manganese-enhanced magnetic resonance imaging can assess functional pancreatic beta-cell mass in people with type 1 diabetes mellitus. METHODS: In a prospective case-control study, 20 people with type 1 diabetes mellitus (10 with low (≥50 pmol/L) and 10 with very low (<50 pmol/L) C-peptide concentrations) and 15 healthy volunteers underwent manganese-enhanced magnetic resonance imaging of the pancreas following an oral glucose load. Scan-rescan reproducibility was performed in 10 participants. RESULTS: Mean pancreatic manganese uptake was 31 ± 6 mL/100 g of tissue/min in healthy volunteers (median 32 [interquartile range 23-36] years, 6 women), falling to 23 ± 4 and 13 ± 5 mL/100 g of tissue/min (p ≤ 0.002 for both) in people with type1 diabetes mellitus (52 [44-61] years, 6 women) and low or very low plasma C-peptide concentrations respectively. Pancreatic manganese uptake correlated strongly with plasma C-peptide concentrations in people with type1 diabetes mellitus (r = 0.73, p < 0.001) but not in healthy volunteers (r = -0.054, p = 0.880). There were no statistically significant correlations between manganese uptake and age, body-mass index, or glycated haemoglobin. There was strong intra-observer (mean difference: 0.31 (limits of agreement -1.42 to 2.05) mL/100 g of tissue/min; intra-class correlation, ICC = 0.99), inter-observer (-1.23 (-5.74 to 3.27) mL/100 g of tissue/min; ICC = 0.85) and scan-rescan (-0.72 (-2.9 to 1.6) mL/100 g of tissue/min; ICC = 0.96) agreement for pancreatic manganese uptake. CONCLUSIONS: Manganese-enhanced magnetic resonance imaging provides a potential reproducible non-invasive measure of functional beta-cell mass in people with type 1 diabetes mellitus. This holds major promise for investigating type 1 diabetes, monitoring disease progression and assessing novel immunomodulatory interventions.

Keratin intrinsic fluorescence as a mechanism for non-invasive monitoring of its glycation.

We have studied the evolution of keratin intrinsic fluorescence as an indicator of its glycation. Steady-state and time-resolved fluorescence of free keratin and keratin-glucose samples were detected in PBS solutionsin vitro. The changes in the fluorescence response demonstrate that the effect of glucose is manifest in the accelerated formation of fluorescent cross-links with an emission peak at 460 nm and formation of new cross-links with emission peaks at 525 nm and 575 nm. The fluorescence kinetics of these structures is studied and their potential application for the detection of long-term complications of diabetes discussed.

Estimation of Early Graft Function Using the BETA-2 Score Following Clinical Islet Transplantation.

Little is known about how early islet graft function evolves in the clinical setting. The BETA-2 score is a validated index of islet function that can be calculated from a single blood sample and lends itself to frequent monitoring of graft function. In this study, we characterized early graft function by calculating weekly BETA-2 score in recipients who achieved insulin independence after single transplant (group 1, n = 8) compared to recipients who required a second transplant before achieving insulin independence (group 2, n = 7). We also determined whether graft function 1-week post-transplant was associated with insulin independence in individuals who received initial transplant between 2000-2017 (n = 125). Our results show that graft function increased rapidly reaching a plateau 4-6 weeks post-transplant. The BETA-2 score was higher in group 1 compared to group 2 as early as 1-week post-transplant (15 + 3 vs. 9 + 2, p = 0.001). In an unselected cohort, BETA-2 at 1-week post-transplant was associated with graft survival as defined by insulin independence during median follow up of 12 months (range 2-119 months) with greater survival among those with BETA-2 score >10 (p < 0.001, log-rank test). These findings suggest that primary graft function is established within 4-6 weeks post-transplant and graft function at 1-week post-transplant predicts long-term transplant outcomes.

HbA1c Is Disproportionately Higher in Women and Older People With Type 1 Diabetes Compared With Flash Glucose Monitoring Metrics of Glycemic Control.

AIMS: Discrepancy between HbA1c and glucose exposure may have significant clinical implications. We sought to assess predictors of disparity between HbA1c and flash monitoring metrics and how these relate to microvascular complications. METHODS: We conducted a cross-sectional study of adults with type 1 diabetes (n = 518). We assessed the relationship between clinic HbA1c and flash monitoring metrics, predictors of discrepancy between these measurements, and whether discrepancy was associated with microvascular complications. RESULTS: Actual HbA1c and estimated HbA1c were strongly correlated (r = .779, P < .001). The likelihood of having a higher actual HbA1c than estimated HbA1c was greater with increasing age (OR = 1.055 per year, P < .001) and lower in men (OR = .208, P < .001). HbA1c was significantly lower in men (58 mmol/mol [51-67]) (7.5% [6.8-8.3]) compared to women (61 mmol/mol [54-70], P = .021) (7.7% [7.1-8.6]), despite no significant differences in any flash monitoring metrics. Whereas HbA1c was not different between younger (≤39 years) and older individuals (>39 years) despite significantly higher glucose exposure, in younger people, based on multiple flash monitoring metrics. Having a lower estimated than actual HbA1c was independently associated with a lower prevalence of retinopathy (OR = .55, P = .004). CONCLUSIONS: HbA1c appears to overestimate glucose exposure in women and older people with type 1 diabetes. This has potentially important clinical implications, as is hinted at by the independent relationship with retinopathy prevalence. It may also be of relevance when considering the use of HbA1c for the diagnosis of diabetes.

Study protocol: a randomised controlled proof-of-concept real-world study - does maximising time in range using hybrid closed loop insulin delivery and a low carbohydrate diet restore the glucagon response to hypoglycaemia in adults with type 1 diabetes?

INTRODUCTION: People with type 1 diabetes (T1D) develop an impaired glucagon response to hypoglycaemia within 5 years of diagnosis, increasing their risk of severe hypoglycaemia. It is not known whether eliminating hypoglycaemia and hyperglycaemia allows recovery of this glucagon response. Hybrid closed loop (HCL) technologies improve glycaemic time in range (TIR). However, post-prandial glycaemic excursions are still evident. Consuming a low carbohydrate diet (LCD) may minimise these excursions. METHODS AND ANALYSIS: This feasibility study will assess if maximising TIR (glucose ≥3.9 mmol/L≤10 mmol/L) using HCL systems plus an LCD (defined here as <130 g carbohydrate/day) for >8 months, restores the glucagon response to insulin-induced hypoglycaemia. Adults (n=24) with T1D (C-peptide <200 pmol/L), naïve to continuous glucose monitoring (CGM) and HCL systems, will be recruited and randomised to: group 1 (non-HCL) to continue their standard diabetes care with intermittent blinded CGM; or group 2 (HCL-LCD) to use the HCL system and follow a LCD. Baseline data on diet and glycaemia will be collected from all participants. The HCL-LCD group will then enter a 2-week run-in to acclimatise to their devices. Throughout, the HCL-LCD group will have their glucose closely monitored and adjusted aiming for glycaemic TIR >70%. Participants will have their glucagon response to hypoglycaemia measured at the beginning and 8 months later at the study end using a stepped hyperinsulinaemic hypoglycaemic clamp, in combination with the stable isotopes 6,6-2H2-glucose (D2-glucose) and 1,1,2,3,3-2H5-glycerol (D5-glycerol) to assess glucose and glycerol kinetics. The impact of hypoglycaemia on symptoms and cognitive function will be assessed during each clamp study. The primary outcome is the difference in the glucagon response to hypoglycaemia between and within groups at baseline versus study end. ETHICS AND DISSEMINATION: Ethical (20/SS/0117)/institutional review board (2021/0001) approval has been obtained. The study will be disseminated by peer-reviewed publications and conference presentations. TRIAL REGISTRATION NUMBER: NCT04614168.

The impact of islet mass, number of transplants, and time between transplants on graft function in a national islet transplant program.

The UK islet allotransplant program is nationally funded to deliver one or two transplants over 12 months to individuals with type 1 diabetes and recurrent severe hypoglycemia. Analyses were undertaken 10 years after program inception to evaluate associations between transplanted mass; single versus two transplants; time between two transplants and graft survival (stimulated C-peptide >50 pmol/L) and function. In total, 84 islet transplant recipients were studied. Uninterrupted graft survival over 12 months was attained in 23 (68%) single and 47 (94%) (p = .002) two transplant recipients (separated by [median (IQR)] 6 (3-8) months). 64% recipients of one or two transplants with uninterrupted function at 12 months sustained graft function at 6 years. Total transplanted mass was associated with Mixed Meal Tolerance Test stimulated C-peptide at 12 months (p < .01). Despite 1.9-fold greater transplanted mass in recipients of two versus one islet infusion (12 218 [9291-15 417] vs. 6442 [5156-7639] IEQ/kg; p < .0001), stimulated C-peptide was not significantly higher. Shorter time between transplants was associated with greater insulin dose reduction at 12 months (beta -0.35; p = .02). Graft survival over the first 12 months was greater in recipients of two versus one islet transplant in the UK program, although function at 1 and 6 years was comparable. Minimizing the interval between 2 islet infusions may maximize cumulative impact on graft function.

Substantial HbA1c Reduction Following Intermittent-Scanning Continuous Glucose Monitoring Was Not Associated With Early Worsening of Retinopathy in Type 1 Diabetes.

BACKGROUND: Early worsening of diabetic retinopathy (EWDR) was observed in the intensively treated arm of the Diabetes Control and Complications Trial (DCCT) before long-term benefits accrued. We sought to assess whether there may be an increased risk of EWDR in high-risk individuals following intermittent-scanning continuous glucose monitoring (iscCGM) commencement. METHODS: An observational study of 139 individuals with type 1 diabetes ≥5 years duration and with baseline HbA1c >75 mmol/mol (9.0%). This cohort was stratified by subsequent HbA1c response to iscCGM (best responders and non-responders). Pan-retinal photocoagulation (PRP), worsening retinopathy status and new development of retinopathy were compared between groups. RESULTS: HbA1c change was -23 mmol/mol (IQR -32 to -19) (-2.1% [-2.9 to -1.8]) in responders and +6 mmol/mol (2-12) (+0.6 [0.2-1.1]) in non-responders (P < .001). There was no difference in subsequent PRP between responders (14.1%) and non-responders (10.3%, P = .340). Baseline HbA1c (HR 1.052 per mmol/mol, P = .002) but not response category (HR 1.244, P = .664) was independently associated with the risk of requiring PRP. Worsening of retinopathy was not different between responders (16.9%) and non-responders (20.6%, P = .577), and the same was true with respect to new development of retinopathy (33.3% vs 31.8%, P = .919). CONCLUSIONS: In a cohort enriched for risk of diabetic retinopathy, reduction in HbA1c did not result in an increased risk of PRP, worsening retinopathy, or new development of retinopathy. These findings offer reassurance that substantial reduction in HbA1c is not independently associated with early worsening of diabetic eye disease in iscCGM users.

Considerations and challenges of islet transplantation and future therapies on the horizon.

Islet transplantation is a treatment for selected adults with type 1 diabetes and severe hypoglycemia. Islets from two or more donor pancreases, a scarce resource, are usually required to impact glycemic control, but the treatment falls short of a cure. Islets are avascular when transplanted into the hypoxic liver environment and subjected to inflammatory insults, immune attack, and toxicity from systemic immunosuppression. The Collaborative Islet Transplant Registry, with outcome data on over 1,000 islet transplant recipients, has demonstrated that larger islet numbers transplanted and older age of recipients are associated with better outcomes. Induction with T-cell depleting agents and the TNF-α inhibitor etanercept and maintenance systemic immunosuppression with mTOR inhibitors in combination with calcineurin inhibitors also appear advantageous, but concerns remain over immunosuppressive toxicity. We discuss strategies and therapeutics that address specific challenges of islet transplantation, many of which are at the preclinical stage of development. On the horizon are adjuvant cell therapies with mesenchymal stromal cells and regulatory T cells that have been used in preclinical models and in humans in other contexts; such a strategy may enable reductions in immunosuppression in the early peri-transplant period when the islets are vulnerable to apoptosis. Human embryonic stem cell-derived islets are in early-phase clinical trials and hold the promise of an inexhaustible supply of insulin-producing cells; effective encapsulation of such cells or, silencing of the human leukocyte antigen (HLA) complex would eliminate the need for immunosuppression, enabling this therapy to be used in all those with type 1 diabetes.

Collagen Glycation Detected by Its Intrinsic Fluorescence.

Collagen's long half-life (in skin approximately 10 years) makes this protein highly susceptible to glycation and formation of the advanced glycation end products (AGEs). Accumulation of cross-linking AGEs in the skin collagen has several detrimental effects; thus, the opportunity for non-invasive monitoring of skin glycation is essential, especially for diabetic patients. In this paper, we report using the time-resolved intrinsic fluorescence of collagen as a biomarker of its glycation. Contrary to the traditional fluorescence intensity decay measurement at the arbitrarily selected excitation and detection wavelengths, we conducted systematic wavelength- and time-resolved measurements to achieve time-resolved emission spectra. Changes in the intrinsic fluorescence kinetics, caused by both collagen aggregation and glycation, have been detected.

Continuous subcutaneous insulin infusion therapy is associated with reduced retinopathy progression compared with multiple daily injections of insulin.

AIMS/HYPOTHESIS: We aimed to compare diabetic retinopathy outcomes in people with type 1 diabetes following introduction of continuous subcutaneous insulin infusion (CSII) therapy with outcomes in people receiving continuing therapy with multiple daily insulin injections (MDI). METHODS: This is a retrospective cohort study using the Scottish Care Information - Diabetes database for retinal screening outcomes and HbA1c changes in 204 adults commenced on CSII therapy between 2013 and 2016, and 211 adults eligible for CSII during the same period but who continued on MDI therapy. Diabetic retinopathy progression (time to minimum one-grade worsening in diabetic retinopathy from baseline grading) was plotted for CSII and MDI cohorts using Kaplan-Meier curves, and outcomes were compared using multivariate Cox regression analysis adjusting for age, sex, baseline HbA1c, blood pressure, cholesterol, smoking status and socioeconomic quintile. Impact of baseline HbA1c and change in HbA1c on diabetic retinopathy progression was assessed within CSII and MDI cohorts. RESULTS: CSII participants were significantly younger, were from less socially deprived areas, and had lower HbA1c and higher diastolic BP at baseline. There was a larger reduction in HbA1c at 1 year in those on CSII vs MDI (-6 mmol/mol [-0.6%] vs -2 mmol/mol [-0.2%], p < 0.01). Diabetic retinopathy progression occurred in a smaller proportion of adults following commencement of CSII vs continued MDI therapy over mean 2.3 year follow-up (26.5% vs 18.6%, p = 0.0097). High baseline HbA1c (75 mmol/mol [9%]) was associated with diabetic retinopathy progression in the MDI group (p = 0.0049) but not the CSII group (p = 0.93). Change in HbA1c at follow-up, irrespective of baseline glycaemic status, did not significantly affect diabetic retinopathy progression in either group. CONCLUSIONS/INTERPRETATION: CSII was associated with reduced diabetic retinopathy progression compared with continued MDI therapy, and may be protective against diabetic retinopathy progression for those with high baseline HbA1c. Progression of diabetic retinopathy over 3 years was not associated with a change in HbA1c.

Detecting beta-amyloid glycation by intrinsic fluorescence - Understanding the link between diabetes and Alzheimer's disease.

We monitor early stages of beta-amyloid (Aß1-40) aggregation, one of the key processes leading to Alzheimer's disease (AD), in the presence of high glucose concentrations by measuring Aß1- 40 intrinsic fluorescence. The multiple peaks and their shifts observed in the time-resolved emission spectra (TRES) reveal the impact of glycation on Aß1- 40 oligomerisation. The results show that formation of the advanced glycation end products (AGEs) alters the aggregation pathway. These changes are highly relevant to our understanding of the pathophysiology of AD and the implication of AGE and diabetes in these pathways.