Preventing severe hypoglycemia in adults with type 2 diabetes (PHT2): Design, delivery and evaluation framework for a randomized controlled trial

BACKGROUND

Severe hypoglycemia is a common and feared complication of medications used to lower blood glucose levels in individuals with diabetes. Psychoeducational interventions can prevent severe hypoglycemia in individuals with type 1 diabetes (T1D). We aim to determine the effectiveness of this approach among adults with type 2 diabetes (T2D) at elevated risk for severe hypoglycemia.

METHODS

Preventing Hypoglycemia in Type 2 diabetes (PHT2) is a two-arm, parallel, randomized controlled trial. Participants are eligible if they are adults with T2D receiving care at an integrated group practice in Washington state and have experienced one or more episodes of severe hypoglycemia in the prior 12 months or have impaired awareness of hypoglycemia (Gold score ≥ 4). Participants are randomized to proactive nurse care management with or without my hypo compass, an evidence-based, psychoeducational intervention combining group and individual self-management training. For this study, my hypo compass was adapted to be suitable for adults with T2D and from an in-person to a virtual intervention over videoconference and telephone. The primary outcome is any self-reported severe hypoglycemia in the 12 months following the start of the intervention. Secondary outcomes include biochemical measures of hypoglycemia, self-reported hypoglycemia awareness, fear of hypoglycemia, and emergency department visits and hospitalizations for severe hypoglycemia. The study includes a process evaluation to assess implementation fidelity and clarify the causal pathway.

CONCLUSION

The PHT2 trial will compare the effectiveness of two approaches for reducing severe hypoglycemia in adults with T2D.

TRIAL REGISTRATION

clinicaltrials.gov, # NCT04863872.

Hypoglycaemia symptom frequency, severity, burden, and utility among adults with type 1 diabetes and impaired awareness of hypoglycaemia: Baseline and 24-week findings from the HypoCOMPaSS study

AIMS

To determine the frequency, severity, burden, and utility of hypoglycaemia symptoms among adults with type 1 diabetes (T1D) and impaired awareness of hypoglycaemia (IAH) at baseline and week 24 following the HypoCOMPaSS awareness restoration intervention.

METHODS

Adults (N = 96) with T1D (duration: 29 ± 12 years; 64% women) and IAH completed the Hypoglycaemia Burden Questionnaire (HypoB-Q), assessing experience of 20 pre-specified hypoglycaemia symptoms, at baseline and week 24.

RESULTS

At baseline, 93 (97%) participants experienced at least one symptom (mean ± SD 10.6 ± 4.6 symptoms). The proportion recognising each specific symptom ranged from 15% to 83%. At 24 weeks, symptom severity and burden appear reduced, and utility increased.

CONCLUSIONS

Adults with T1D and IAH experience a range of hypoglycaemia symptoms. Perceptions of symptom burden or utility are malleable. Although larger scale studies are needed to confirm, these findings suggest that changing the salience of the symptomatic response may be more important in recovering protection from hypoglycaemia through regained awareness than intensifying symptom frequency or severity.

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.

The Relevance of Advanced Therapy Medicinal Products in the Field of Transplantation and the Need for Academic Research Access: Overcoming Bottlenecks and Claiming a New Time

The field of transplantation has witnessed the emergence of Advanced Therapy Medicinal Products (ATMPs) as highly promising solutions to address the challenges associated with organ and tissue transplantation. ATMPs encompass gene therapy, cell therapy, and tissue-engineered products, hold immense potential for breakthroughs in overcoming the obstacles of rejection and the limited availability of donor organs. However, the development and academic research access to ATMPs face significant bottlenecks that hinder progress. This opinion paper emphasizes the importance of addressing bottlenecks in the development and academic research access to ATMPs by implementing several key strategies. These include the establishment of streamlined regulatory processes, securing increased funding for ATMP research, fostering collaborations and partnerships, setting up centralized ATMP facilities, and actively engaging with patient groups. Advocacy at the policy level is essential to provide support for the development and accessibility of ATMPs, thereby driving advancements in transplantation and enhancing patient outcomes. By adopting these strategies, the field of transplantation can pave the way for the introduction of innovative and efficacious ATMP therapies, while simultaneously fostering a nurturing environment for academic research.

Validation of Igls Criteria for Islet Transplant Functional Status Using Person-Reported Outcome Measures in a Cross-Sectional Study

Associations between islet graft function and well-being in islet transplant recipients requiring exogenous insulin remain unclear. This cross-sectional analysis compared person-reported outcome measures in 15 adults with type 1 diabetes whose islet transplants were classified according to Igls criteria as "Good" (n = 5), "Marginal" (n = 4) and "Failed" (n = 6) graft function. At a mean of 6.2 years post-first islet transplant, 90% reduction in severe hypoglycaemia was maintained in all groups, with HbA1c (mean ± SD mmol/mol) 49 ± 4 in recipients with "Good" function; 56 ± 5 ("Marginal"); and 69 ± 25 ("Failed"). Self-reported impaired awareness of hypoglycaemia persisted in all groups but those with "Good" function were more likely to experience symptoms during hypoglycaemia. "Marginal" function was associated with greater fear of hypoglycaemia (HFS-II score: "Marginal": 113 [95, 119]; "Failed": 63 [42, 93] (p = 0.082); "Good": 33 [29, 61]) and severe anxiety (GAD7: "Marginal"): 21 [17, 21]; "Failed": 6 [6, 6] "Good": 6 [3, 11]; (p = 0.079)), diabetes distress and low mood. Despite clear evidence of ongoing clinical benefit, Igls criteria 'Marginal' function is associated with sub-optimal well-being, including greater fear of hypoglycaemia and severe anxiety. This study provides person-reported validation that "Good" and "Marginal" graft function are differentiated by general and diabetes-specific subjective well-being, suggesting those with "Marginal" function may benefit from further intervention, including re-transplantation.

Characterization of impaired beta and alpha cell function in response to an oral glucose challenge in cystic fibrosis: a cross-sectional study

Aims

The purpose of the study was to further elucidate the pathophysiology of cystic fibrosis (CF)-related diabetes (CFRD) and potential drivers of hypoglycaemia. Hence, we aimed to describe and compare beta cell function (insulin and proinsulin) and alpha cell function (glucagon) in relation to glucose tolerance in adults with CF and to study whether hypoglycaemia following oral glucose challenge may represent an early sign of islet cell impairment.

Methods

Adults with CF (≥18 years) were included in a cross-sectional study using an extended (-10, -1, 10, 20, 30, 45, 60, 90, 120, 150, and 180 min) or a standard (-1, 30, 60, and 120 min) oral glucose tolerance test (OGTT). Participants were classified according to glucose tolerance status and hypoglycaemia was defined as 3-hour glucose <3.9 mmol/L in those with normal glucose tolerance (NGT) and early glucose intolerance (EGI).

Results

Among 93 participants, 67 underwent an extended OGTT. In addition to worsening in insulin secretion, the progression to CFRD was associated with signs of beta cell stress, as the fasting proinsulin-to-insulin ratio incrementally increased (p-value for trend=0.013). The maximum proinsulin level (pmol/L) was positively associated with the nadir glucagon, as nadir glucagon increased 6.2% (95% confidence interval: 1.4-11.3%) for each unit increase in proinsulin. Those with hypoglycaemia had higher 60-min glucose, 120-min C-peptide, and 180-min glucagon levels (27.8% [11.3-46.7%], 42.9% [5.9-92.85%], and 80.3% [14.9-182.9%], respectively) and unaltered proinsulin-to-insulin ratio compared to those without hypoglycaemia.

Conclusions

The maximum proinsulin concentration was positively associated with nadir glucagon during the OGTT, suggesting that beta cell stress is associated with abnormal alpha cell function in adults with CF. In addition, hypoglycaemia seemed to be explained by a temporal mismatch between glucose and insulin levels rather than by an impaired glucagon response.

Changes in attitudes to awareness of hypoglycaemia during a hypoglycaemia awareness restoration programme are associated with avoidance of further severe hypoglycaemia episodes within 24 months: the A2A in HypoCOMPaSS study

AIMS/HYPOTHESIS

The aims of this study were to assess cognitions relating to hypoglycaemia in adults with type 1 diabetes and impaired awareness of hypoglycaemia before and after the multimodal HypoCOMPaSS intervention, and to determine cognitive predictors of incomplete response (one or more severe hypoglycaemic episodes over 24 months).

METHODS

This analysis included 91 adults with type 1 diabetes and impaired awareness of hypoglycaemia who completed the Attitudes to Awareness of Hypoglycaemia (A2A) questionnaire before, 24 weeks and 24 months after the intervention, which comprised a short psycho-educational programme with optimisation of insulin therapy and glucose monitoring.

RESULTS

The age and diabetes duration of the participants were 48±12 and 29±12 years, respectively (mean±SD). At baseline, 91% reported one or more severe hypoglycaemic episodes over the preceding 12 months; this decreased to <20% at 24 weeks and after 24 months (p=0.001). The attitudinal barrier 'hyperglycaemia avoidance prioritised' (η²_p=0.250, p=0.001) decreased from baseline to 24 weeks, and this decrease was maintained at 24 months (mean±SD=5.3±0.3 vs 4.3±0.3 vs 4.0±0.3). The decrease in 'asymptomatic hypoglycaemia normalised' from baseline (η²_p=0.113, p=0.045) was significant at 24 weeks (1.5±0.3 vs 0.8±0.2). Predictors of incomplete hypoglycaemia response (one or more further episodes of severe hypoglycaemia) were higher baseline rates of severe hypoglycaemia, higher baseline scores for 'asymptomatic hypoglycaemia normalised', reduced change in 'asymptomatic hypoglycaemia normalised' scores at 24 weeks, and lower baseline 'hypoglycaemia concern minimised' scores (all p<0.05).

CONCLUSIONS/INTERPRETATION

Participation in the HypoCOMPaSS RCT was associated with improvements in hypoglycaemia-associated cognitions, with 'hyperglycaemia avoidance prioritised' most prevalent. Incomplete prevention of subsequent severe hypoglycaemia episodes was associated with persistence of the cognition 'asymptomatic hypoglycaemia normalised'. Understanding and addressing cognitive barriers to hypoglycaemia avoidance is important in individuals prone to severe hypoglycaemia episodes.

CLINICAL TRIALS REGISTRATION

www.isrctn.org : ISRCTN52164803 and https://eudract.ema.europa.eu : EudraCT2009-015396-27.

Pseudoislet Aggregation of Pancreatic β-Cells Improves Glucose Stimulated Insulin Secretion by Altering Glucose Metabolism and Increasing ATP Production

Appropriate glucose-stimulated insulin secretion (GSIS) by pancreatic β-cells is an essential component of blood glucose homeostasis. Configuration of β-cells as 3D pseudoislets (PI) improves the GSIS response compared to 2D monolayer (ML) culture. The aim of this study was to determine the underlying mechanisms. MIN6 β-cells were grown as ML or PI for 5 days. Human islets were isolated from patients without diabetes. Function was assessed by GSIS and metabolic capacity using the Seahorse bioanalyser. Connexin 36 was downregulated using inducible shRNA. Culturing MIN6 as PI improved GSIS. MIN6 PI showed higher glucose-stimulated oxygen consumption (OCR) and extracellular acidification (ECAR) rates. Further analysis showed the higher ECAR was, at least in part, a consequence of increased glycolysis. Intact human islets also showed glucose-stimulated increases in both OCR and ECAR rates, although the latter was smaller in magnitude compared to MIN6 PI. The higher rates of glucose-stimulated ATP production in MIN6 PI were consistent with increased enzyme activity of key glycolytic and TCA cycle enzymes. There was no impact of connexin 36 knockdown on GSIS or ATP production. Configuration of β-cells as PI improves GSIS by increasing the metabolic capacity of the cells, allowing higher ATP production in response to glucose.

Capturing the real-world benefit of residual β-cell function during clinically important time-periods in established Type 1 diabetes

AIMS

Many individuals with type 1 diabetes retain residual β-cell function, with increased endogenous insulin secretion associated with reduced hyperglycaemia, hypoglycaemia and glycaemic variability. However, it is unknown when these improvements occur during the day. Dysglycaemia is common in overnight and postprandial periods and associated with diabetes complications. Therefore, this study aimed to determine the influence of residual β-cell function upon nocturnal and postprandial glycaemic control in established type 1 diabetes.

METHODS

Under free-living conditions, 66 participants wore a blinded continuous glucose monitor (CGM), kept a food diary, and completed a stimulated urine C-peptide creatinine (UCPCR) test. Nocturnal, and postprandial CGM outcomes (participant means and discrete event analysis) were compared between UCPCR groups: undetectable (Cpep_und ), low (Cpep_low : 0.001-0.19 nmol/mmol) and high (Cpep_high : ≥0.2 nmol/mmol).

RESULTS

Greater β-cell function was associated with incremental improvements in glycaemia. Cpep_high spent significantly greater time in normoglycaemia than Cpep_und overnight (76 ± 20% vs. 58 ± 20%, p = 0.005) and 0-300 mins postprandially (68 ± 22% vs. 51 ± 22%, p = 0.045), while also having reducing nocturnal variability (SD 1.12 ± 0.41 vs. 1.52 ± 0.43 mmol/L, p = 0.010). Analysis of individual events, controlling for diabetes duration, BMI, basal insulin, use of a continuous or flash glucose monitor and (for postprandial) meal type, carbohydrate and bolus insulin intake, replicated the group findings, additionally demonstrating Cpep_und had increased hyperglycaemia versus Cpep_low overnight and increased postprandial hypoglycaemic events compared with Cpep_high . For all participants, breakfast had a significantly higher incremental area under the curve than lunch and dinner.

CONCLUSIONS

Residual β-cell function is associated with improved nocturnal and postprandial glycaemic control. These data may be of clinical importance for identifying specific periods and individuals where further glycaemic management strategies would be beneficial.

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.

Restoring normal islet mass and function in type 1 diabetes through regenerative medicine and tissue engineering

Type 1 diabetes is characterised by autoimmune-mediated destruction of pancreatic β-cell mass. With the advent of insulin therapy a century ago, type 1 diabetes changed from a progressive, fatal disease to one that requires lifelong complex self-management. Replacing the lost β-cell mass through transplantation has proven successful, but limited donor supply and need for lifelong immunosuppression restricts widespread use. In this Review, we highlight incremental advances over the past 20 years and remaining challenges in regenerative medicine approaches to restoring β-cell mass and function in type 1 diabetes. We begin by summarising the role of endocrine islets in glucose homoeostasis and how this is altered in disease. We then discuss the potential regenerative capacity of the remaining islet cells and the utility of stem cell-derived β-like cells to restore β-cell function. We conclude with tissue engineering approaches that might improve the engraftment, function, and survival of β-cell replacement therapies.

Pancreatic islet reserve in type 1 diabetes

Type 1 diabetes (T1D) is a chronic autoimmune disease characterized by pancreatic islet β cell loss and dysfunction resulting in insulin deficiency and hyperglycemia. During a presymptomatic phase of established β cell autoimmunity, β cell loss may first be evident through assessment of β cell secretory capacity, a measure of functional β cell mass. Reduction in pancreatic islet β cell reserve eventually manifests as impaired first-phase insulin response to glucose and abnormal glucose tolerance, which progresses until the functional capacity for β cell secretion can no longer meet the demand for insulin to control glycemia. A functional β cell mass of ∼25% of normal may be required to avoid symptomatic T1D but is already associated with dysregulated glucagon secretion. With symptomatic T1D, stimulated C-peptide levels >0.60 ng/mL (0.200 pmol/mL) indicate the presence of clinically meaningful residual β cell function for contributing to glycemic control, although even higher residual C-peptide appears necessary for evidencing glucose-dependent islet β and α cell function that may contribute to maintaining (near)normal glycemia. β cell replacement by islet transplantation can restore a physiologic reserve capacity for insulin secretion, confirming thresholds for functional β cell mass required for independence from insulin therapy.

2-year remission of type 2 diabetes and pancreas morphology: a post-hoc analysis of the DiRECT open-label, cluster-randomised trial

BACKGROUND

The pancreas is small and irregular in shape in people with type 2 diabetes. If these abnormalities are caused by the disease state itself rather than being a predisposing factor, remission of type 2 diabetes should restore normal pancreas morphology. The objective of this study was to determine whether changes in pancreas volume and shape occurred during 2 years of remission.

METHODS

For this post-hoc analysis, we included a subset of adult participants of the Diabetes Remission Clinical Trial (DiRECT), who had type 2 diabetes and were randomly assigned to a weight management intervention or routine diabetes management. Intervention group participants were categorised as responders (HbA_1c <6·5% [48 mmol/mol] and fasting blood glucose <7·0 mmol/L, off all anti-diabetes medication) and non-responders, who were classified as remaining diabetic. Data on pancreas volume and irregularity of pancreas border at baseline, 5 months, 12 months, and 24 months after intervention were compared between responders and non-responders; additional comparisons were made between control group participants with type 2 diabetes and a non-diabetic comparator (NDC) group, who were matched to the intervention group by age, sex, and post-weight-loss weight, to determine the extent of any normalisation. We used a mixed-effects regression model based on repeated measures ANOVA with correction for potential confounding. Magnetic resonance techniques were employed to quantify pancreas volume, the irregularity of the pancreas borders, and intrapancreatic fat content. β-cell function and biomarkers of tissue growth were also measured.

FINDINGS

Between July 25, 2015, and Aug 5, 2016, 90 participants with type 2 diabetes in the DiRECT subset were randomly assigned to intervention (n=64) or control (n=26) and were assessed at baseline; a further 25 non-diabetic participants were enrolled into the NDC group. At baseline, mean pancreas volume was 61·7 cm³ (SD 16·0) in all participants with type 2 diabetes and 79·8 cm³ (14·3) in the NDC group (p<0·0001). At 24 months, pancreas volume had increased by 9·4 cm³ (95% CI 6·1 to 12·8) in responders compared with 6·4 cm³ (2·5 to 10·3) in non-responders (p=0·0008). Pancreas borders at baseline were more irregular in participants with type 2 diabetes than in the NDC group (fractal dimension 1·138 [SD 0·027] vs 1·097 [0·025]; p<0·0001) and had normalised by 24 months in responders only (1·099 [0·028]). Intrapancreatic fat declined by 1·02 percentage points (95% CI 0·53 to 1·51) in 32 responders and 0·51% (-0·17 to 1·19) in 13 non-responders (p=0·23).

INTERPRETATION

These data show for the first time, to our knowledge, reversibility of the abnormal pancreas morphology of type 2 diabetes by weight loss-induced remission.

FUNDING

Diabetes UK.

Donor insulin use predicts beta-cell function after islet transplantation

Insulin is routinely used to manage hyperglycaemia in organ donors and during the peri-transplant period in islet transplant recipients. However, it is unknown whether donor insulin use (DIU) predicts beta-cell dysfunction after islet transplantation. We reviewed data from the UK Transplant Registry and the UK Islet Transplant Consortium; all first-time transplants during 2008-2016 were included. Linear regression models determined associations between DIU, median and coefficient of variation (CV) peri-transplant glucose levels and 3-month islet graft function. In 91 islet cell transplant recipients, DIU was associated with lower islet function assessed by BETA-2 scores (β [SE] -3.5 [1.5], P = .02), higher 3-month post-transplant HbA1c levels (5.4 [2.6] mmol/mol, P = .04) and lower fasting C-peptide levels (-107.9 [46.1] pmol/l, P = .02). Glucose at 10 512 time points was recorded during the first 5 days peri-transplant: the median (IQR) daily glucose level was 7.9 (7.0-8.9) mmol/L and glucose CV was 28% (21%-35%). Neither median glucose levels nor glucose CV predicted outcomes post-transplantation. Data on DIU predicts beta-cell dysfunction 3 months after islet transplantation and could help improve donor selection and transplant outcomes.

In Situ Analysis Reveals That CFTR Is Expressed in Only a Small Minority of β-Cells in Normal Adult Human Pancreas

CONTEXT

Although diabetes affects 40% to 50% of adults with cystic fibrosis, remarkably little is known regarding the underlying mechanisms leading to impaired pancreatic β-cell insulin secretion. Efforts toward improving the functional β-cell deficit in cystic fibrosis-related diabetes (CFRD) have been hampered by an incomplete understanding of whether β-cell function is intrinsically regulated by cystic fibrosis transmembrane conductance regulator (CFTR). Definitively excluding meaningful CFTR expression in human β-cells in situ would contribute significantly to the understanding of CFRD pathogenesis.

OBJECTIVE

To determine CFTR messenger ribonucleic acid (mRNA) and protein expression within β-cells in situ in the unmanipulated human pancreas of donors without any known pancreatic pathology.

DESIGN

In situ hybridization for CFTR mRNA expression in parallel with insulin immunohistochemical staining and immunofluorescence co-localization of CFTR with insulin and the ductal marker, Keratin-7 (KRT7), were undertaken in pancreatic tissue blocks from 10 normal adult, nonobese deceased organ donors over a wide age range (23-71 years) with quantitative image analysis.

RESULTS

CFTR mRNA was detectable in a mean 0.45% (range 0.17%-0.83%) of insulin-positive cells. CFTR protein expression was co-localized with KRT7. One hundred percent of insulin-positive cells were immunonegative for CFTR.

CONCLUSIONS

For the first time, in situ CFTR mRNA expression in the unmanipulated pancreas has been shown to be present in only a very small minority (<1%) of normal adult β-cells. These data signal a need to move away from studying endocrine-intrinsic mechanisms and focus on elucidation of exocrine-endocrine interactions in human cystic fibrosis.

Reduced Expression of the Co-regulator TLE1 in Type 2 Diabetes Is Associated with Increased Islet α-Cell Number

β-Cell dysfunction in type 2 diabetes (T2D) is associated with loss of cellular identity and mis-expression of alternative islet hormones, including glucagon. The molecular basis for these cellular changes has been attributed to dysregulation of core β-cell transcription factors, which regulate β-cell identity through activating and repressive mechanisms. The TLE1 gene lies near a T2D susceptibility locus and, recently, the glucagon repressive actions of this transcriptional coregulator have been demonstrated in vitro. We investigated whether TLE1 expression is disrupted in human T2D, and whether this is associated with increased islet glucagon-expressing cells. Automated image analysis following immunofluorescence in donors with (n = 7) and without (n = 7) T2D revealed that T2D was associated with higher islet α/β cell ratio (Control: 0.7 ± 0.1 vs T2D: 1.6 ± 0.4; P < .05) and an increased frequency of bihormonal (insulin+/glucagon+) cells (Control: 0.8 ± 0.2% vs T2D: 2.0 ± 0.4%, P < .05). In nondiabetic donors, the majority of TLE1-positive cells were mono-hormonal β-cells (insulin+/glucagon-: 98.2 ± 0.5%; insulin+/glucagon+: 0.7 ± 0.2%; insulin-/glucagon+: 1.1 ± 0.4%; P < .001). TLE1 expression was reduced in T2D (Control: 36 ± 2.9% vs T2D: 24 ± 2.6%; P < .05). Reduced islet TLE1 expression was inversely correlated with α/β cell ratio (r = -0.55; P < .05). TLE1 knockdown in EndoC-βH1 cells was associated with a 2.5-fold increase in glucagon gene mRNA and mis-expression of glucagon in insulin-positive cells. These data support TLE1 as a putative regulator of human β-cell identity, with dysregulated expression in T2D associated with increased glucagon expression potentially reflecting β- to α-cell conversion.

β-Cell and renal transplantation options for diabetes

Despite major advances in structured education, insulin delivery and glucose monitoring, diabetes self-management remains an unremitting challenge. Insulin therapy is inextricably linked to risk of dangerous hypoglycaemia and sustained hyperglycaemia remains a leading cause of renal failure. This review sets out to demystify transplantation for diabetes multidisciplinary teams, facilitating consideration and incorporation within holistic overall person-centred management. Deceased and living donor kidney, whole pancreas and isolated islet transplant procedures, indications and potential benefits are described, in addition to outcomes within the integrated UK transplant programme.

Targeting CXCR1/2 Does Not Improve Insulin Secretion After Pancreatic Islet Transplantation: A Phase 3, Double-Blind, Randomized, Placebo-Controlled Trial in Type 1 Diabetes

OBJECTIVE

Reparixin is an inhibitor of CXCR1/2 chemokine receptor shown to be an effective anti-inflammatory adjuvant in a pilot clinical trial in allotransplant recipients.

RESEARCH DESIGN AND METHODS

A phase 3, multicenter, randomized, double-blind, parallel-assignment study (NCT01817959) was conducted in recipients of islet allotransplants randomized (2:1) to reparixin or placebo in addition to immunosuppression. Primary outcome was the area under the curve (AUC) for C-peptide during the mixed-meal tolerance test at day 75 ± 5 after the first and day 365 ± 14 after the last transplant. Secondary end points included insulin independence and standard measures of glycemic control.

RESULTS

The intention-to-treat analysis did not show a significant difference in C-peptide AUC at both day 75 (27 on reparixin vs. 18 on placebo, P = 0.99) and day 365 (24 on reparixin vs. 15 on placebo, P = 0.71). There was no statistically significant difference between treatment groups at any time point for any secondary variable. Analysis of patient subsets showed a trend for a higher percentage of subjects retaining insulin independence for 1 year after a single islet infusion in patients receiving reparixin as compared with patients receiving placebo (26.7% vs. 0%, P = 0.09) when antithymocyte globulin was used as induction immunosuppression.

CONCLUSIONS

In this first double-blind randomized trial, islet transplantation data obtained with reparixin do not support a role of CXCR1/2 inhibition in preventing islet inflammation-mediated damage.

Predictors of Recurrent Severe Hypoglycemia in Adults With Type 1 Diabetes and Impaired Awareness of Hypoglycemia During the HypoCOMPaSS Study

OBJECTIVE

The HypoCOMPaSS study was designed to test the hypothesis that successful avoidance of biochemical hypoglycemia without compromising overall glycemic control would restore sufficient hypoglycemia awareness to prevent recurrent severe hypoglycemia in the majority of participants with established type 1 diabetes. Before starting the study, we planned to investigate associations between baseline characteristics and recurrent severe hypoglycemia over 2 years' follow-up.

RESEARCH DESIGN AND METHODS

A total of 96 adults with type 1 diabetes and impaired awareness of hypoglycemia participated in a 24-week 2 × 2 factorial randomized controlled trial comparing insulin delivery and glucose monitoring modalities, with the goal of rigorous biochemical hypoglycemia avoidance. The analysis included 71 participants who had experienced severe hypoglycemia in the 12-month prestudy with confirmed absence (complete responder) or presence (incomplete responder) of severe hypoglycemia over 24 months' follow-up.

RESULTS

There were 43 (61%) complete responders and 28 (39%) incomplete responders experiencing mean ± SD 1.5 ± 1.0 severe hypoglycemia events/person-year. At 24 months, incomplete responders spent no more time with glucose ≤3 mmol/L (1.4 ± 2.1% vs. 3.0 ± 4.8% for complete responders; P = 0.26), with lower total daily insulin dose (0.45 vs. 0.58 units/24 h; P = 0.01) and greater impairment of hypoglycemia awareness (Clarke score: 3.8 ± 2.2 vs. 2.0 ± 1.9; P = 0.01). Baseline severe hypoglycemia rate (16.9 ± 16.3 vs. 6.4 ± 10.8 events/person-year; P = 0.002) and fear of hypoglycemia were higher in incomplete responders. Peripheral neuropathy was more prevalent in incomplete responders (11 [39%] vs. 2 [4.7%]; P < 0.001) with a trend toward increased autonomic neuropathy.

CONCLUSIONS

Recurrent severe hypoglycemia was associated with higher preintervention severe hypoglycemia rate, fear of hypoglycemia, and concomitant neuropathy.

Development and Psychometric Validation of the Novel Glucose Monitoring Experiences Questionnaire Among Adults with Type 1 Diabetes

Background: Glucose monitoring is an essential aspect of self-care for people with type 1 diabetes. With technologies developing rapidly, valid assessment of user experiences and satisfaction is needed. Our aim was to develop a novel measure: the Glucose Monitoring Experiences Questionnaire (GME-Q). Methods: Questionnaire design was informed by exploratory and cognitive debriefing interviews. The GME-Q was included in a large online survey enabling psychometric validation. Results: The interview sample included 17 adults (aged [mean ± SD] 46 ± 11 years, 53% women) with type 1 diabetes duration of 26 ± 14 years. The proposed conceptual framework included three domains: "Effectiveness", "Intrusiveness", and "Convenience", assessed with 25 items plus a single, overview item. The validation sample included 589 adults (aged 44 ± 15 years; 64% women) with type 1 diabetes (duration: 22 ± 14 years, self-monitoring blood glucose [SMBG] using finger-prick devices: median [IQR] 6 [4-7] daily checks). Questionnaire acceptability was indicated: 98% (n = 578) completion rate. After deleting 3 redundant items, principal components analysis supported a 22-item questionnaire with 3 domains ("Effectiveness" [9 items]; "Intrusiveness" [6 items]; "Convenience" [7 items]), accounting for 55% of variance, with good internal consistency reliability (α = 0.83-0.88). Subscales correlated significantly (r_s = ±0.44-0.66, P < 0.001) with the single, overview item, together explaining 51% of the total variance in the single item score. Associations with demographic and clinical characteristics supported convergent and discriminant validity. Conclusions: Overall, the 22-item GME-Q is a brief, acceptable, valid, and reliable measure of satisfaction with glucose monitoring in adults with type 1 diabetes using SMBG, and this needs to be assessed among those using continuous glucose monitoring.

Satisfaction with the Use of Different Technologies for Insulin Delivery and Glucose Monitoring Among Adults with Long-Standing Type 1 Diabetes and Problematic Hypoglycemia: 2-Year Follow-Up in the HypoCOMPaSS Randomized Clinical Trial

Background: In the HypoCOMPaSS trial, adults with long-standing type 1 diabetes and problematic hypoglycemia were randomized to compare insulin pump (continuous subcutaneous insulin infusion; CSII) with multiple daily injections (MDI) and real-time continuous glucose monitoring (RT-CGM) with conventional self-monitoring of blood glucose (SMBG). Our aim was to investigate participants' satisfaction with these technologies at 6-month randomized, controlled trial (RCT) endpoint and at 2-year follow-up. Methods: Participants completed the Insulin Treatment Satisfaction Questionnaire subscales "device delivery" and "hypoglycemia control"; and Glucose Monitoring Experience Questionnaire, assessing "convenience", "effectiveness", "intrusiveness", and "total satisfaction." We assessed change over time and between-group differences by insulin and monitoring modalities. Results: Participants (N = 96) were 64% women, aged 49 ± 12 years, with a diabetes duration of 29 ± 12 years. At 6 months, participants reported improvements compared with baseline (all P < 0.001) in satisfaction with insulin "delivery device" (r = 0.39) and "hypoglycemia control" (r = 0.52), and trends toward significance in perceived "effectiveness" (r = 0.42) and "intrusiveness" (r = 0.27) of monitoring device (but not "convenience", P = 0.139). All improvements were sustained at 2 years. At 6 months, the only difference between arms was that greater satisfaction with insulin "delivery device" was reported in the CSII group compared with MDI (P < 0.001, r = 0.40). No between-group differences were observed at 2 years. Conclusions: Overall, significant improvements in participant satisfaction with diabetes technologies were observed over the 6-month RCT, in all domains except "convenience," and maintained at 2 years. Although HypoCOMPaSS demonstrated noninferiority of SMBG versus CGM, and MDI versus CSII in terms of biomedical outcomes, detailed assessments confirm that participants' satisfaction with delivery device was greater in those allocated to CSII than MDI.

Defining outcomes for β-cell replacement therapy in the treatment of diabetes: a consensus report on the Igls criteria from the IPITA/EPITA opinion leaders workshop

β-cell replacement therapy, available currently as pancreas or islet transplantation, has developed without a clear definition of graft functional and clinical outcomes. The International Pancreas & Islet Transplant Association (IPITA) and European Pancreas & Islet Transplantation Association (EPITA) held a workshop to develop consensus for an IPITA/EPITA Statement on the definition of function and failure of current and future forms of β-cell replacement therapy. There was consensus that β-cell replacement therapy could be considered as a treatment for β-cell failure, regardless of etiology and without requiring undetectable C-peptide, accompanied by glycemic instability with either problematic hypoglycemia or hyperglycemia. Glycemic control should be assessed at a minimum by glycated hemoglobin (HbA_1c ) and the occurrence of severe hypoglycemia. Optimal β-cell graft function is defined by near-normal glycemic control [HbA_1c  ≤ 6.5% (48 mmol/mol)] without severe hypoglycemia or requirement for insulin or other antihyperglycemic therapy, and with an increase over pretransplant measurement of C-peptide. Good β-cell graft function requires HbA_1c  < 7.0% (53 mmol/mol) without severe hypoglycemia and with a significant (>50%) reduction in insulin requirements and restoration of clinically significant C-peptide production. Marginal β-cell graft function is defined by failure to achieve HbA_1c  < 7.0% (53 mmol/mol), the occurrence of any severe hypoglycemia, or less than 50% reduction in insulin requirements when there is restoration of clinically significant C-peptide production documented by improvement in hypoglycemia awareness/severity, or glycemic variability/lability. A failed β-cell graft is defined by the absence of any evidence for clinically significant C-peptide production. Optimal and good functional outcomes are considered successful clinical outcomes.

Sustained Reduction in Severe Hypoglycemia in Adults With Type 1 Diabetes Complicated by Impaired Awareness of Hypoglycemia: Two-Year Follow-up in the HypoCOMPaSS Randomized Clinical Trial

OBJECTIVE

Severe hypoglycemia is a feared complication of type 1 diabetes; yet, few trials have targeted prevention using optimized self-management (educational, therapeutic, and technological support). We aimed to investigate whether improved awareness and reduced severe hypoglycemia, achieved during an intensive randomized clinical trial (RCT), were sustained after return to routine care.

RESEARCH DESIGN AND METHODS

Ninety-six adults with type 1 diabetes (29 ± 12 years' duration) and impaired awareness of hypoglycemia at five U.K. tertiary referral diabetes centers were recruited into a 24-week 2 × 2 factorial RCT (HypoCOMPaSS). Participants were randomized to pump (continuous subcutaneous insulin infusion [CSII]) or multiple daily injections (MDIs) and real-time continuous glucose monitoring (RT-CGM) or self-monitoring of blood glucose (SMBG), with equal education/attention to all groups. At 24 weeks, participants returned to routine care with follow-up until 24 months, including free choice of MDI/CSII; RT-CGM vs. SMBG comparison continued to 24 months. Primary outcome was mean difference (baseline to 24 months [between groups]) in hypoglycemia awareness.

RESULTS

Improvement in hypoglycemia awareness was sustained (Gold score at baseline 5.1 ± 1.1 vs. 24 months 3.7 ± 1.9; P < 0.0001). Severe hypoglycemia rate was reduced from 8.9 ± 12.8 episodes/person-year over the 12 months prestudy to 0.4 ± 0.8 over 24 months (P < 0.0001). HbA_1c improved (baseline 8.2 ± 3.2% [66 ± 12 mmol/mol] vs. 24 months 7.7 ± 3.1% [61 ± 10 mmol/mol]; P = 0.003). Improvement in treatment satisfaction and reduced fear of hypoglycemia were sustained. There were no significant differences between interventions at 24 months.

CONCLUSIONS

Optimized insulin replacement and glucose monitoring underpinned by hypoglycemia-focused structured education should be provided to all with type 1 diabetes complicated by impaired awareness of hypoglycemia.

Loss of end-differentiated β-cell phenotype following pancreatic islet transplantation

Replacement of pancreatic β-cells through deceased donor islet transplantation is a proven therapy for preventing recurrent life-threatening hypoglycemia in type 1 diabetes. Although near-normal glucose levels and insulin independence can be maintained for many years following successful islet transplantation, restoration of normal functional β-cell mass has remained elusive. It has recently been proposed that dedifferentiation/plasticity towards other endocrine phenotypes may play an important role in stress-induced β-cell dysfunction in type 2 diabetes. Here we report loss of end-differentiated β-cell phenotype in 2 intraportal islet allotransplant recipients. Despite excellent graft function and sustained insulin independence, all examined insulin-positive cells had lost expression of the end-differentiation marker, urocortin-3, or appeared to co-express the α-cell marker, glucagon. In contrast, no insulin⁺ /urocortin-3^- cells were seen in nondiabetic deceased donor control pancreatic islets. Loss of end-differentiated phenotype may facilitate β-cell survival during the stresses associated with islet isolation and culture, in addition to sustained hypoxia following engraftment. As further refinements in islet isolation and culture are made in parallel with exploration of alternative β-cell sources, graft sites, and ultimately fully vascularized bioengineered insulin-secreting microtissues, differentiation status immunostaining provides a novel tool to assess whether fully mature β-cell phenotype has been maintained.

Glucagon-Like Peptide 1 Protects Pancreatic β-Cells From Death by Increasing Autophagic Flux and Restoring Lysosomal Function

Studies in animal models of type 2 diabetes have shown that glucagon-like peptide 1 (GLP-1) receptor agonists prevent β-cell loss. Whether GLP-1 mediates β-cell survival via the key lysosomal-mediated process of autophagy is unknown. In this study, we report that treatment of INS-1E β-cells and primary islets with glucolipotoxicity (0.5 mmol/L palmitate and 25 mmol/L glucose) increases LC3 II, a marker of autophagy. Further analysis indicates a blockage in autophagic flux associated with lysosomal dysfunction. Accumulation of defective lysosomes leads to lysosomal membrane permeabilization and release of cathepsin D, which contributes to cell death. Our data further demonstrated defects in autophagic flux and lysosomal staining in human samples of type 2 diabetes. Cotreatment with the GLP-1 receptor agonist exendin-4 reversed the lysosomal dysfunction, relieving the impairment in autophagic flux and further stimulated autophagy. Small interfering RNA knockdown showed the restoration of autophagic flux is also essential for the protective effects of exendin-4. Collectively, our data highlight lysosomal dysfunction as a critical mediator of β-cell loss and shows that exendin-4 improves cell survival via restoration of lysosomal function and autophagic flux. Modulation of autophagy/lysosomal homeostasis may thus define a novel therapeutic strategy for type 2 diabetes, with the GLP-1 signaling pathway as a potential focus.

Type 2 Diabetes: The Pathologic Basis of Reversible β-Cell Dysfunction

The reversible nature of early type 2 diabetes has been demonstrated in in vivo human studies. Recent in vivo and in vitro studies of β-cell biology have established that the β-cell loses differentiated characteristics, including glucose-mediated insulin secretion, under metabolic stress. Critically, the β-cell dedifferentiation produced by long-term excess nutrient supply is reversible. Weight loss in humans permits restoration of first-phase insulin secretion associated with the return to normal of the elevated intrapancreatic triglyceride content. However, in type 2 diabetes of duration greater than 10 years, the cellular changes appear to pass a point of no return. This review summarizes the evidence that early type 2 diabetes can be regarded as a reversible β-cell response to chronic positive calorie balance.

Characterizing problematic hypoglycaemia: iterative design and preliminary psychometric validation of the Hypoglycaemia Awareness Questionnaire (HypoA-Q)

AIMS

To design and conduct preliminary validation of a measure of hypoglycaemia awareness and problematic hypoglycaemia, the Hypoglycaemia Awareness Questionnaire.

METHODS

Exploratory and cognitive debriefing interviews were conducted with 17 adults (nine of whom were women) with Type 1 diabetes (mean ± sd age 48 ± 10 years). Questionnaire items were modified in consultation with diabetologists/psychologists. Psychometric validation was undertaken using data from 120 adults (53 women) with Type 1 diabetes (mean ± sd age 44 ± 16 years; 50% with clinically diagnosed impaired awareness of hypoglycaemia), who completed the following questionnaires: the Hypoglycaemia Awareness Questionnaire, the Gold score, the Clarke questionnaire and the Problem Areas in Diabetes questionnaire.

RESULTS

Iterative design resulted in 33 items eliciting responses about awareness of hypoglycaemia when awake/asleep and hypoglycaemia frequency, severity and impact (healthcare utilization). Psychometric analysis identified three subscales reflecting 'impaired awareness', 'symptom level' and 'symptom frequency'. Convergent validity was indicated by strong correlations between the 'impaired awareness' subscale and existing measures of awareness: (Gold: rs =0.75, P < 0.01; Clarke: rs =0.76, P < 0.01). Divergent validity was indicated by weaker correlations with diabetes-related distress (Problem Areas in Diabetes: rs =0.25, P < 0.01) and HbA1c (rs =-0.05, non-significant). The 'impaired awareness' subscale and other items discriminated between those with impaired and intact awareness (Gold score). The 'impaired awareness' subscale and other items contributed significantly to models explaining the occurrence of severe hypoglycaemia and hypoglycaemia when asleep.

CONCLUSIONS

This preliminary validation shows the Hypoglycaemia Awareness Questionnaire has robust face and content validity; satisfactory structure; internal reliability; convergent, divergent and known groups validity. The impaired awareness subscale and other items contribute significantly to models explaining recall of severe and nocturnal hypoglycaemia. Prospective validation, including determination of a threshold to identify impaired awareness, is now warranted.

De Novo Donor-Specific HLA Antibodies Are Associated With Rapid Loss of Graft Function Following Islet Transplantation in Type 1 Diabetes

Outcomes after islet transplantation continue to improve but etiology of graft failure remains unclear. De novo donor-specific human leukocyte antigen (HLA) antibodies (DSA) posttransplant are increasingly recognized as a negative prognostic marker. Specific temporal associations between DSA and graft function remain undefined particularly in programs undertaking multiple sequential transplants. Impact of de novo DSA on graft function over 12 months following first islet transplant was determined prospectively in consecutive recipients taking tacrolimus/mycophenolate immunosuppression at a single center. Mixed-meal tolerance test was undertaken in parallel with HLA antibody assessment pretransplant and 1-3 months posttransplant. Sixteen participants received a total of 26 islet transplants. Five (19%) grafts were associated with de novo DSA. Five (31%) recipients were affected: three post-first transplant; two post-second transplant. DSA developed within 4 weeks of all sensitizing grafts and were associated with decreased stimulated C-peptide (median [interquartile range]) at 3 months posttransplant (DSA negative: 613(300-1090); DSA positive 106(34-235) pmol/L [p = 0.004]). De novo DSA directed against most recent islet transplant were absolutely associated with loss of graft function despite maintained immunosuppression at 12 months in the absence of a rescue nonsensitizing transplant. Alemtuzumab induction immunosuppression was associated with reduced incidence of de novo DSA formation (p = 0.03).

The UK Pancreas Allocation Scheme for Whole Organ and Islet Transplantation

In order to develop a national allocation scheme for donor pancreases, factors affecting waiting time and transplant outcomes in the United States (US) and United Kingdom (UK) were analyzed and compared. Blood group, sensitization, dialysis requirement, and whether the patient was waiting for a kidney and pancreas or pancreas alone affected waiting time in both countries; ethnicity and body mass index (BMI) also affected waiting time in the US. Ninety-day pancreas survival was similar in the UK and US, and was poorer for patients receiving a pancreas alone, with older donors, higher BMI and longer duration of ischemia in both countries. Factors affecting outcome, together with published data on factors affecting islet transplantation, informed the development of a points based allocation scheme for deceased donor pancreases in the UK providing equitable access for both whole organ and islet recipients through a single waiting list. Analysis of the allocation scheme 3 years after its introduction in December 2010 showed that the results were broadly as simulated, with a significant reduction in the number of long waiting patients and an increase in the number of islet transplants. There remains a surplus of highly sensitized patients in the waiting list, which the scheme should address in time.

Demonstration of an intrinsic relationship between endogenous C-peptide concentration and determinants of glycemic control in type 1 diabetes following islet transplantation

OBJECTIVE

Maintenance of endogenous pancreatic β-cell function could be an important goal in the management of type 1 diabetes. However, the impact of stimulated C-peptide level on overall glycemic control is unknown. The relationship between C-peptide and parameters of glucose control was therefore characterized in a cohort with rapidly changing β-cell function following islet transplantation.

RESEARCH DESIGN AND METHODS

Standardized mixed-meal tolerance test was undertaken in 12 consecutive islet recipients at 1-6-month intervals, with graft function determined by 90-min stimulated C-peptide. Continuous glucose monitoring was undertaken in the week preceding each assessment and the relationship between C-peptide and glucose control evaluated by mixed Poisson regression.

RESULTS

Recipients completed 5 (1-14) [median (range)] clinical assessments over 18 (1-51) months posttransplant encompassing a wide range of stimulated C-peptide levels (7-2,622 pmol/L). Increasing β-cell function across predefined C-peptide groups was associated with reduced insulin dose, HbA1c, mean glucose (low [<200 pmol/L] 10.7 vs. excellent [>1,000 pmol/L] 7.5 mmol/L), and glucose SD (low, 4.4 vs. excellent, 1.4 mmol/L). Highly statistically significant continuous associations between stimulated C-peptide and mean interstitial glucose (lower by 2.5% [95% CI 1.5-3.5%] per 100 pmol/L higher C-peptide), glucose SD, time outside glucose target range, and measures of hyper-/hypoglycemia risk were confirmed.

CONCLUSIONS

Repeated assessment of islet transplant recipients has enabled modeling of the relationship between endogenous β-cell function and measures of glycemic control providing quantitative estimates of likely impact of an acute change in β-cell function in individuals with type 1 diabetes.

Recovery of hypoglycemia awareness in long-standing type 1 diabetes: a multicenter 2 × 2 factorial randomized controlled trial comparing insulin pump with multiple daily injections and continuous with conventional glucose self-monitoring (HypoCOMPaSS)

OBJECTIVE

To determine whether impaired awareness of hypoglycemia (IAH) can be improved and severe hypoglycemia (SH) prevented in type 1 diabetes, we compared an insulin pump (continuous subcutaneous insulin infusion [CSII]) with multiple daily injections (MDIs) and adjuvant real-time continuous glucose monitoring (RT) with conventional self-monitoring of blood glucose (SMBG).

RESEARCH DESIGN AND METHODS

A 24-week 2 × 2 factorial randomized controlled trial in adults with type 1 diabetes and IAH was conducted. All received comparable education, support, and congruent therapeutic targets aimed at rigorous avoidance of biochemical hypoglycemia without relaxing overall control. Primary end point was between-intervention difference in 24-week hypoglycemia awareness (Gold score).

RESULTS

A total of 96 participants (mean diabetes duration 29 years) were randomized. Overall, biochemical hypoglycemia (≤3.0 mmol/L) decreased (53 ± 63 to 24 ± 56 min/24 h; P = 0.004 [t test]) without deterioration in HbA1c. Hypoglycemia awareness improved (5.1 ± 1.1 to 4.1 ± 1.6; P = 0.0001 [t test]) with decreased SH (8.9 ± 13.4 to 0.8 ± 1.8 episodes/patient-year; P = 0.0001 [t test]). At 24 weeks, there was no significant difference in awareness comparing CSII with MDI (4.1 ± 1.6 vs. 4.2 ± 1.7; difference 0.1; 95% CI -0.6 to 0.8) and RT with SMBG (4.3 ± 1.6 vs. 4.0 ± 1.7; difference -0.3; 95% CI -1.0 to 0.4). Between-group analyses demonstrated comparable reductions in SH, fear of hypoglycemia, and insulin doses with equivalent HbA1c. Treatment satisfaction was higher with CSII than MDI (32 ± 3 vs. 29 ± 6; P = 0.0003 [t test]), but comparable with SMBG and RT (30 ± 5 vs. 30 ± 5; P = 0.79 [t test]).

CONCLUSIONS

Hypoglycemia awareness can be improved and recurrent SH prevented in long-standing type 1 diabetes without relaxing HbA1c. Similar biomedical outcomes can be attained with conventional MDI and SMBG regimens compared with CSII/RT, although satisfaction was higher with CSII.

Home urine C-peptide creatinine ratio can be used to monitor islet transplant function

OBJECTIVE

Islet graft function is defined by serum C-peptide in a standardized challenge test. We assessed whether urine C-peptide creatinine ratio (UCPCR) sent from home could provide a viable alternative.

RESEARCH DESIGN AND METHODS

Seventeen islet recipients provided 90-min serum C-peptide (sCP90) and 120-min UCPCR (UCPCR120) samples during 68 interval posttransplant mixed-meal tolerance tests, also posting from home a 120-min postbreakfast UCPCR sample every 2 weeks. UCPCR was compared with a clinical score of islet function, derived from HbA1c and insulin dose.

RESULTS

UCPCR120 and mean home postmeal UCPCR were strongly correlated with sCP90 (r(s) = 0.73, P < 0.001; and rs = 0.73, P < 0.01, respectively). Mean home UCPCR increased with clinical score (r(s) = 0.75; P < 0.001) and with graft function defined both by sCP90 >200 pmol/L and insulin independence. UCPCR cutoffs to detect insulin independence and poor graft function were sensitive and specific.

CONCLUSIONS

Home UCPCR provides a valid measure of C-peptide production in islet transplant recipients.

Severe hypoglycaemia in type 1 diabetes mellitus: underlying drivers and potential strategies for successful prevention

Hypoglycaemia remains an over-riding factor limiting optimal glycaemic control in type 1 diabetes. Severe hypoglycaemia is prevalent in almost half of those with long-duration diabetes and is one of the most feared diabetes-related complications. In this review, we present an overview of the increasing body of literature seeking to elucidate the underlying pathophysiology of severe hypoglycaemia and the limited evidence behind the strategies employed to prevent episodes. Drivers of severe hypoglycaemia including impaired counter-regulation, hypoglycaemia-associated autonomic failure, psychosocial and behavioural factors and neuroimaging correlates are discussed. Treatment strategies encompassing structured education, insulin analogue regimens, continuous subcutaneous insulin infusion pumps, continuous glucose sensing and beta-cell replacement therapies have been employed, yet there is little randomized controlled trial evidence demonstrating effectiveness of new technologies in reducing severe hypoglycaemia. Optimally designed interventional trials evaluating these existing technologies and using modern methods of teaching patients flexible insulin use within structured education programmes with the specific goal of preventing severe hypoglycaemia are required. Individuals at high risk need to be monitored with meticulous collection of data on awareness, as well as frequency and severity of all hypoglycaemic episodes.

Attainment of metabolic goals in the integrated UK islet transplant program with locally isolated and transported preparations

The objective was to determine whether metabolic goals have been achieved with locally isolated and transported preparations over the first 3 years of the UK's nationally funded integrated islet transplant program. Twenty islet recipients with C-peptide negative type 1 diabetes and recurrent severe hypoglycemia consented to the study, including standardized meal tolerance tests. Participants received a total of 35 infusions (seven recipients: single graft; 11 recipients: two grafts: two recipients: three grafts). Graft function was maintained in 80% at [median (interquartile range)] 24 (13.5-36) months postfirst transplant. Severe hypoglycemia was reduced from 20 (7-50) episodes/patient-year pretransplant to 0.3 (0-1.6) episodes/patient-year posttransplant (p < 0.001). Resolution of impaired hypoglycemia awareness was confirmed [pretransplant: Gold score 6 (5-7); 24 (13.5-36) months: 3 (1.5-4.5); p < 0.03]. Target HbA1c of <7.0% was attained/maintained in 70% of recipients [pretransplant: 8.0 (7.0-9.6)%; 24 (13.5-36) months: 6.2 (5.7-8.4)%; p < 0.001], with 60% reduction in insulin dose [pretransplant: 0.51 (0.41-0.62) units/kg; 24 (13.5-36) months: 0.20 (0-0.37) units/kg; p < 0.001]. Metabolic outcomes were comparable 12 months posttransplant in those receiving transported versus only locally isolated islets [12 month stimulated C-peptide: transported 788 (114-1764) pmol/L (n = 9); locally isolated 407 (126-830) pmol/L (n = 11); p = 0.32]. Metabolic goals have been attained within the equitably available, fully integrated UK islet transplant program with both transported and locally isolated preparations.

Restoration of self-awareness of hypoglycemia in adults with long-standing type 1 diabetes: hyperinsulinemic-hypoglycemic clamp substudy results from the HypoCOMPaSS trial

OBJECTIVE

Impaired awareness of hypoglycemia (IAH) and defective counterregulation significantly increase severe hypoglycemia risk in type 1 diabetes (T1D). We evaluated restoration of IAH/defective counterregulation by a treatment strategy targeted at hypoglycemia avoidance in adults with T1D with IAH (Gold score ≥4) participating in the U.K.-based multicenter HypoCOMPaSS randomized controlled trial.

RESEARCH DESIGN AND METHODS

Eighteen subjects with T1D and IAH (mean ± SD age 50 ± 9 years, T1D duration 35 ± 10 years, HbA1c 8.1 ± 1.0% [65 ± 10.9 mmol/mol]) underwent stepped hyperinsulinemic-hypoglycemic clamp studies before and after a 6-month intervention. The intervention comprised the HypoCOMPaSS education tool in all and randomized allocation, in a 2 × 2 factorial study design, to multiple daily insulin analog injections or continuous subcutaneous insulin infusion therapy and conventional glucose monitoring or real-time continuous glucose monitoring. Symptoms, cognitive function, and counterregulatory hormones were measured at each glucose plateau (5.0, 3.8, 3.4, 2.8, and 2.4 mmol/L), with each step lasting 40 min with subjects kept blinded to their actual glucose value throughout clamp studies.

RESULTS

After intervention, glucose concentrations at which subjects first felt hypoglycemic increased (mean ± SE from 2.6 ± 0.1 to 3.1 ± 0.2 mmol/L, P = 0.02), and symptom and plasma metanephrine responses to hypoglycemia were higher (median area under curve for symptoms, 580 [interquartile range {IQR} 420-780] vs. 710 [460-1,260], P = 0.02; metanephrine, 2,412 [-3,026 to 7,279] vs. 5,180 [-771 to 11,513], P = 0.01). Glycemic threshold for deterioration of cognitive function measured by four-choice reaction time was unchanged, while the color-word Stroop test showed a degree of adaptation.

CONCLUSIONS

Even in long-standing T1D, IAH and defective counterregulation may be improved by a clinical strategy aimed at hypoglycemia avoidance.

Expression of mesenchymal and α-cell phenotypic markers in islet β-cells in recently diagnosed diabetes

OBJECTIVE

Relative contributions of reversible β-cell dysfunction and true decrease in β-cell mass in type 2 diabetes remain unclear. Definitive rodent lineage-tracing studies have identified β-cell dedifferentiation and subsequent reprogramming to α-cell fate as a novel mechanism underlying β-cell failure. The aim was to determine whether phenotypes of β-cell dedifferentiation and plasticity are present in human diabetes.

RESEARCH DESIGN AND METHODS

Immunofluorescence colocalization studies using classical endocrine and mesenchymal phenotypic markers were undertaken using pancreatic sections and isolated islets from three individuals with diabetes and five nondiabetic control subjects.

RESULTS

Intraislet cytoplasmic coexpression of insulin and vimentin, insulin and glucagon, and vimentin and glucagon were demonstrated in all cases. These phenotypes were not present in nondiabetic control subjects.

CONCLUSIONS

Coexpression of mesenchymal and α-cell phenotypic markers in human diabetic islet β-cells has been confirmed, providing circumstantial evidence for β-cell dedifferentiation and possible reprogramming to α-cells in clinical diabetes.

Novel diabetes mellitus treatment: mature canine insulin production by canine striated muscle through gene therapy

Muscle-targeted gene therapy using insulin genes has the potential to provide an inexpensive, low maintenance alternative or adjunctive treatment method for canine diabetes mellitus. A canine skeletal muscle cell line was established through primary culture, as well as through transdifferentiation of canine fibroblasts after infection with a myo-differentiation gene containing adenovirus vector. A novel mutant furin-cleavable canine preproinsulin gene insert (cppI4) was designed and created through de novo gene synthesis. Various cell lines, including the generated canine muscle cell line, were transfected with nonviral plasmids containing cppI4. Insulin and desmin immunostaining were used to prove insulin production by muscle cells and specific canine insulin ELISA to prove mature insulin secretion into the medium. The canine myoblast cultures proved positive on desmin immunostaining. All cells tolerated transfection with cppI4-containing plasmid, and double immunostaining for insulin and desmin proved present in the canine cells. Canine insulin ELISA assessment of medium of cppI4-transfected murine myoblasts and canine myoblast and fibroblast mixture proved presence of mature fully processed canine insulin, 24 and 48 h after transfection. The present study provides proof of principle that canine muscle cells can be induced to produce and secrete canine insulin on transfection with nonviral plasmid DNA containing a novel mutant canine preproinsulin gene that produces furin-cleavable canine preproinsulin. This technology could be developed to provide an alternative canine diabetes mellitus treatment option or to provide a constant source for background insulin, as well as C-peptide, alongside current treatment options.

Evaluation of a quality-of-life tool for dogs with diabetes mellitus

BACKGROUND

Diabetes mellitus (DM) management primarily focuses on improvement in blood glucose concentrations and clinical signs. A tool to assess the psychological and social impact of DM and its treatment on quality of life (QoL) previously has only been validated for feline DM.

HYPOTHESIS/OBJECTIVES

To validate a diabetic pet and owner-centered individualized measure of impact of DM (DIAQoL-pet) for diabetic dogs and their owners. ANIMALS/SUBJECTS: A total of 101 owners of insulin-treated diabetic dogs were recruited to complete the DIAQoL-pet.

METHODS

Discussions and pilot surveys with clinicians and owners of diabetic pets led to the design of 29 specific DM-associated QoL questions. Each item was scored according to impact frequency and perceived importance. An Item-Weighted-Impact-Score (IWIS) for each item was calculated, as was an Average-Weighted-Impact-Score (AWIS) by averaging all IWISs. Principal component analysis and Cronbach's α calculation assessed the measure's reliability.

RESULTS

The DIAQoL-pet showed high reliability (Communalities ≥0.5; Cronbach's α 0.85). The AWIS was -2.74 ± 1.7 (mean ± SD). Areas reported as most negatively impacting QoL included: "worry" (IWIS ± SD: -5.92 ± 4.3), "difficulties leaving dog with friends or family" (-5.68 ± 5.1), "worry vision" (-5.58 ± 4.6), "boarding difficulties" (-5.18 ± 5.2), "worry hypoglycemia" (-4.95 ± 4.3), "social life" (-4.82 ± 4.4), "costs" (-4.11 ± 4.7), and "future care"(-4.07 ± 4.6). Eighty-four percent of owners reported negative impact of DM on QoL.

CONCLUSIONS AND CLINICAL IMPORTANCE

The DIAQoL-pet proved robust when used by owners of insulin-treated diabetic dogs and identified specific areas most negatively impacting dogs' and their owners' QoL. This tool could be used as an additional assessment parameter in clinical and research settings.

Validation of Islet Transport From a Geographically Distant Isolation Center Enabling Equitable Access and National Health Service Funding of a Clinical Islet Transplant Program for England

Islet transplantation has become established as a successful treatment for type 1 diabetes complicated by recurrent severe hypoglycemia. In the UK access has been limited to a few centrally located units. Our goal was to validate a quality-assured system for safe/effective transport of human islets in the UK and to successfully undertake the first transplants with transported islets. Pancreases were retrieved from deceased donors in the north of England and transported to King's College London using two-layer method (TLM) or University of Wisconsin solution alone. Islets were isolated and transported back to Newcastle in standard blood transfusion or gas-permeable bags with detailed evaluation pre- and posttransport. In the preclinical phase, islets were isolated from 10 pancreases with mean yield of 258,000 islet equivalents. No significant differences were seen between TLM and University of Wisconsin solution organ preservation. A significant loss of integrity was demonstrated in islets shipped in gas-permeable bags, whereas sterility, number, purity, and viability were maintained in blood transfusion bags. Maintenance of secretory granules and glucose-stimulated insulin secretion was confirmed following transport. A Standard Operating Procedure enabling final pretransplant quality control from a simple side-arm sample was validated. Moreover, levels of insulin and cytokines in transport medium were low, enabling transplant without centrifugation/resuspension at the recipient site. Six clinical transplants of transported islets were undertaken in five recipients with 100% primary graft function and resolution of severe hypoglycemia. Safe and clinically effective islet transport has been established facilitating sustainable NHS funding of a clinical islet transplant program for the UK.

Pluripotency-associated stem cell marker expression in proliferative cell cultures derived from adult human pancreas

The source of new β-cells in adult human pancreas remains incompletely elucidated with recent studies on rodents providing evidence for neogenesis from progenitor cells in addition to self-replication. The aim of this study was to investigate the expression of pluripotency-associated stem cell markers in proliferative cultures derived from adult human pancreas. Human pancreatic tissue was obtained from deceased donors following ethical approval and relative consent. Islet-enriched fraction was separated from the retrieved organ by digestion and density gradient centrifugation. Dissociated cells were seeded in adherent culture forming proliferative 'islet survivor cells' (ISCs). These were characterised at fifth passage by RT-PCR, immunofluorescence staining, FACS, western blot and transfection studies with an OCT4 promoter-driven reporter. Nuclear expression of the pluripotency-associated stem cell marker complex OCT4/SOX2/NANOG was confirmed in ISCs. The phenotype constituted ∼8% of the overall population. OCT4 biosynthesis was confirmed by western blot and activation of an exogenous OCT4 promoter. Co-expression of pluripotency-associated markers has been confirmed in proliferative primary cells derived from adult human pancreas. Further studies are required to elucidate whether these cells possess functional stem cell characteristics and assess potential for differentiation into pancreatic cell lineages including new β-cells.

Insulin pump therapy with automated insulin suspension in response to hypoglycemia: reduction in nocturnal hypoglycemia in those at greatest risk

OBJECTIVE

To evaluate a sensor-augmented insulin pump with a low glucose suspend (LGS) feature that automatically suspends basal insulin delivery for up to 2 h in response to sensor-detected hypoglycemia.

RESEARCH DESIGN AND METHODS

The LGS feature of the Paradigm Veo insulin pump (Medtronic, Inc., Northridge, CA) was tested for 3 weeks in 31 adults with type 1 diabetes.

RESULTS

There were 166 episodes of LGS: 66% of daytime LGS episodes were terminated within 10 min, and 20 episodes lasted the maximum 2 h. LGS use was associated with reduced nocturnal duration ≤2.2 mmol/L in those in the highest quartile of nocturnal hypoglycemia at baseline (median 46.2 vs. 1.8 min/day, P = 0.02 [LGS-OFF vs. LGS-ON]). Median sensor glucose was 3.9 mmol/L after 2-h LGS and 8.2 mmol/L at 2 h after basal restart.

CONCLUSIONS

Use of an insulin pump with LGS was associated with reduced nocturnal hypoglycemia in those at greatest risk and was well accepted by patients.

Transgene expression in mononuclear muscle cells not infiltrating inflammatory cells following intramuscular plasmid gene electrotransfer

BACKGROUND

In situ electroporation-assisted intramuscular plasmid DNA delivery offers high efficiency for therapeutic protein replacement. Expression may be impaired by an immune response against the plasmid or transgenic protein. Expression of the transgene in non-muscle cells may increase the immune response. Gene transfer efficiency and phenotypic identification of intramuscular transgene-expressing mononuclear cells was studied following electroporation-mediated plasmid delivery.

METHODS

Plasmids expressing beta-galactosidase (pVR1012-betagal) or enhanced green fluorescent protein (eGFP) (pVR1012-eGFP) were electrotransferred into rat tibialis anterior muscles. Both transfection efficiency and the inflammatory response were determined in pVR1012-betagal-injected muscles by beta-galactosidase and haematoxylin and eosin staining of muscles 7 days post-plasmid injection. Muscles injected with pVR1012-eGFP were stained for CD3, CD68 and desmin at 24 and 48 h post-injection to determine whether mononuclear cells expressing eGFP were of immune or myogenic origin.

RESULTS

With electroporation, beta-galactosidase expression was significantly enhanced by up to ten-fold compared to plasmid injection without electroporation. A large area of regenerating muscle fibres and inflammatory cell infiltration was found in electroporated plasmid-injected muscle. No eGFP expression was found in CD3- or CD68-positive cells. Small mononuclear cells expressing eGFP showed negative staining for CD3 and CD68, but all stained positive for desmin.

CONCLUSIONS

In situ electroporation enhanced transfection efficiency of plasmid DNA delivery into muscle. Alongside its advantage for improving gene transfer, electroporation led to an increased inflammatory response and muscle damage. Mononuclear cells in muscle were transfected with plasmid and expressed the transgene. These cells were of myogenic origin with no evidence of transgene expression in infiltrating inflammatory cells.

Patient-reported outcomes following islet cell or pancreas transplantation (alone or after kidney) in Type 1 diabetes: a systematic review

AIMS

For selected individuals with complex Type 1 diabetes, pancreatic islet transplantation (IT) offers the potential of excellent glycaemic control without significant hypoglycaemia, balanced by the need for ongoing systemic immunosuppression. Increasingly, patient-reported outcomes (PROs) are considered alongside biomedical outcomes as a measure of transplant success. PROs in IT have not previously been compared directly with the closest alternate treatment option, pancreas transplant alone (PTA) or pancreas after kidney (PAK).

METHODS

We used a Population, Intervention, Comparisons, Outcomes (PICO) strategy to search Scopus and screened 314 references for inclusion.

RESULTS

Twelve studies [including PRO assessment of PAK, PTA, islet-after kidney (IAK) and islet transplant alone (ITA); n = 7-205] used a total of nine specified and two unspecified PRO measures. Results were mixed but identified some benefits which remained apparent up to 36 months post-transplant, including improvements in fear of hypoglycaemia, as well as some aspects of diabetes-specific quality of life (QoL) and general health status. Negative outcomes included short-term pain associated with the procedure, immunosuppressant side effects and depressed mood associated with loss of graft function.

CONCLUSIONS

The mixed results may be attributable to limited sample sizes. Also, some PRO measures may lack sensitivity to detect actual changes, as they exclude issues and domains of life likely to be important for QoL post-transplantation and when patients may no longer perceive themselves to have diabetes. Thus, the full impact of islet/pancreas transplantation (alone or after kidney) on QoL is unknown. Furthermore, no studies have assessed patient satisfaction, which may highlight further advantages and disadvantages of transplantation.