Patient-reported outcomes for older adults on CamAPS FX closed loop system

AIMS

Use of the CamAPS FX hybrid closed loop (CL) system is associated with improved time in range and glycated haemoglobin A1c across the age span, but little is known about its effects on patient-reported outcomes (PROs).

METHODS

This open-label, randomized, multi-site study compared CamAPS FX to sensor-augmented pump (SAP) in a sample of older adults (≥60 years) with type 1 diabetes (T1D). Thirty-five older adults completed PROs surveys at the start of the study and after each period of 16 weeks using either CL or SAP. At the end of the study, 19 participated in interviews about their experiences with CL.

RESULTS

Results examining the 16 weeks of CL use showed that the overall Diabetes Distress Scale score and two subscales (powerlessness and physician distress) improved significantly along with trust on the Glucose Monitoring Satisfaction Survey. User experience interview responses were consistent in noting benefits of 'improved glycaemic control' and 'worrying less about diabetes'.

CONCLUSION

In this sample of older adults with T1D who have previously shown glycaemic benefit, there are indicators of improved PROs and subjective user experience benefits.

Concordance of three point of care testing devices with clinical chemistry laboratory standard assays and patient-reported outcomes of blood sampling methods

Background

Point of care testing (POCT) devices have been developed to facilitate immediate results with the potential to aid screening for new disease and enable patients to self-monitor their disease. Non-communicable diseases (NCDs) are the major cause of mortality globally and are increasing in prevalence as the population ages. Allied health care professionals (AHPs) are skilled in undertaking risk assessment and delivering preventative advice, providing opportunities to access large proportions of the population who may not visit their doctor, within non-traditional community settings. There is evidence of high levels of support from public, patients and health professionals for engaging AHPs in risk-targeted early case detection of certain NCDs. Thus, POCT devices offer a potential alternative to traditional venous blood collection, as novel care pathways for increasing early case detection and access to preventative care. The objectives of this study were to: (i) determine the concordance of the specific POCT devices with laboratory-based standard assays employed within clinical biochemistry laboratories. (ii) compare the sampling experience of both methods via patient-reported experiences.

Methods

A prospective, two-centre study was undertaken involving 158 participants who provided informed consent. Venous blood was collected for traditional assays of HbA1c, creatinine/ estimated Glomerular-Filtration-Rate (eGFR) and vitamin-D. Capillary blood was collected by finger prick test and also assayed for the same biochemical indices (Nova StatSensor (creatinine/eGFR); Siemens DCA-Vantage (HbA1C); CityAssays (vitamin-D)). All users were provided with device training. Participants reported any discomfort experienced by each simultaneously applied method (randomised in order) via a 100 mm Visual-Analogue-Scale.

Results

Results for each POCT device and the laboratory standard were analysed by Bland-Altman plots to determine assay concordance. POCT devices demonstrated good concordance with laboratory testing, with at least 95% of all samples being within two standard deviations, for each of the devices tested. The majority of participants reported less discomfort with POCT than venepuncture, with the average reported discomfort being 17/100 mm less for POCT compared to venous blood sample collection on the visual analogue scale.

Conclusions

The POCT devices demonstrated acceptable concordance with laboratory-based assays, and patients reported lower levels of discomfort compared to traditional means of blood collection. This study demonstrates the potential of using these devices as acceptable methods for opportunistic testing of “at-risk” individuals within non-traditional community care settings.

Flash glucose monitoring with the FreeStyle Libre 2 compared with self-monitoring of blood glucose in suboptimally controlled type 1 diabetes: the FLASH-UK randomised controlled trial protocol

INTRODUCTION

Optimising glycaemic control in type 1 diabetes (T1D) remains challenging. Flash glucose monitoring with FreeStyle Libre 2 (FSL2) is a novel alternative to the current standard of care self-monitoring of blood glucose (SMBG). No randomised controlled trials to date have explored the potential benefits of FSL2 in T1D. We aim to assess the impact of FSL2 in people with suboptimal glycaemic control T1D in comparison with SMBG.

METHODS

This open-label, multicentre, randomised (via stochastic minimisation), parallel design study conducted at eight UK secondary and primary care centres will aim to recruit 180 people age ≥16 years with T1D for >1 year and glycated haemoglobin (HbA1c) 7.5%-11%. Eligible participants will be randomised to 24 weeks of FSL2 (intervention) or SMBG (control) periods, after 2-week of blinded sensor wear. Participants will be assessed virtually or in-person owing to the COVID-19 pandemic. HbA1c will be measured at baseline, 12 and 24 weeks (primary outcome). Participants will be contacted at 4 and 12 weeks for glucose optimisation. Control participants will wear a blinded sensor during the last 2 weeks. Psychosocial outcomes will be measured at baseline and 24 weeks. Secondary outcomes include sensor-based metrics, insulin doses, adverse events and self-report psychosocial measures. Utility, acceptability, expectations and experience of using FSL2 will be explored. Data on health service resource utilisation will be collected.

ANALYSIS

Efficacy analyses will follow intention-to-treat principle. Outcomes will be analysed using analysis of covariance, adjusted for the baseline value of the corresponding outcome, minimisation factors and other known prognostic factors. Both within-trial and life-time economic evaluations, informed by modelling from the perspective of the National Health Service setting, will be performed.

ETHICS

The study was approved by Greater Manchester West Research Ethics Committee (reference 19/NW/0081). Informed consent will be sought from all participants.

TRIAL REGISTRATION NUMBER

NCT03815006.

PROTOCOL VERSION

4.0 dated 29 June 2020.

The increased risk of microvascular complications in South Asians with type 1 diabetes is influenced by migration

AIM

We aimed to explore the association between South Asian ethnicity and complications of type 1 diabetes, and whether this is affected by migration.

METHODS

In this retrospective cohort study, data on diabetes control and complications were obtained for South Asians in India (South Asians_India , n = 2592) and the UK (South Asians_UK , n = 221) and white Europeans in the UK (n = 1431). Multivariable logistic regression was used to identify associations between ethnicity and diabetic kidney disease, retinopathy and neuropathy adjusting for age, sex, BMI, disease duration, HbA_1c , blood pressure (BP) and cholesterol.

RESULTS

South Asians_India had significantly greater adjusted odds of diabetic kidney disease [odds ratio (OR) 5.0, 95% confidence intervals (CI) 3.6-7.1] and retinopathy (OR 1.8, 95% CI 1.2-2.5), but lower odds of neuropathy (OR 0.5, 95% CI 0.4-0.6) than white Europeans. South Asians_India had significantly greater adjusted odds of diabetic kidney disease (OR 3.0, 95% 1.8-5.3) than South Asians_UK , but there was no significant difference in the odds of other complications.

CONCLUSIONS

In this hypothesis-generating study, we report that South Asian ethnicity is associated with greater risk of diabetic kidney disease and retinopathy, and lower risk of neuropathy than white European ethnicity. Part of the excess diabetic kidney disease risk is reduced in South Asians_UK . These associations cannot be accounted for by differences in vascular risk factors. Our findings in South Asians with type 1 diabetes mirror previous findings in type 2 diabetes and now need to be validated in a study of the effect of ethnicity on type 1 diabetes complications where healthcare is provided in the same setting.

Guidelines for the management of diabetes services and patients during the COVID-19 pandemic

The UK National Diabetes Inpatient COVID Response Group was formed at the end of March 2020 to support the provision of diabetes inpatient care during the COVID pandemic. It was formed in response to two emerging needs. First to ensure that basic diabetes services are secured and maintained at a time when there was a call for re-deployment to support the need for general medical expertise across secondary care services. The second was to provide simple safe diabetes guidelines for use by specialists and non-specialists treating inpatients with or suspected of COVID-19 infection. To date the group, comprising UK-based specialists in diabetes, pharmacy and psychology, have produced two sets of guidelines which will be continually revised as new evidence emerges. It is supported by Diabetes UK, the Association of British Clinical Diabetologists and NHS England.

Development of a group structured education programme to support safe exercise in people with Type 1 diabetes: the EXTOD education programme

AIM

To develop a structured education programme for individuals with Type 1 diabetes who are engaging in regular exercise.

METHOD

A multidisciplinary team of experts in supporting exercise and physical activity for people with Type 1 diabetes, alongside researchers with experience of developing self-management education, developed an exercise programme using the Medical Research Council framework. The programme was informed by a review of the evidence relating to Type 1 diabetes and exercise, the behaviour change literature (including the behaviour change taxonomy), and qualitative interviews with stakeholders. The programme and supporting resources were refined using an iterative process of testing, delivery and collecting feedback from participants and the wider development team.

RESULTS

The outcome of the intervention development was the design of a feasible and acceptable intervention for people with Type 1 diabetes to support safe exercise. The pilot allowed refinement of the intervention prior to testing in a two-site feasibility randomized controlled trial. Key findings from the pilot informed minor restructuring of the timetable (timings and order) and adaptation of supporting educational materials (participant handbook and teaching materials).

CONCLUSION

The 'EXercise in people with Type One Diabetes' (EXTOD) education programme has been developed using robust methodology for the generation of educational interventions. It now needs testing in a randomized controlled trial.

The mobilisation of early mature CD56dim-CD16bright NK cells is blunted following a single bout of vigorous intensity exercise in Type 1 Diabetes

Type 1 diabetes (T1D) is a T cell mediated autoimmune disease that targets and destroys insulin-secreting pancreatic beta cells. Although T cell mediated, a number of other immune cells are also critically involved in coordinating the events leading to T1D. Specifically, innate subsets play an important role in the pathogenesis of T1D. NK cells are one of the first cell types to infiltrate the pancreas, causing damage and release of beta cell antigens. Previous work in our group has shown differential mobilisation of highly differentiated CD8+ T cells during vigorous intensity exercise in T1D compared to a control cohort. Here, we aimed to explore exercise-induced mobilisation of other cell types involved in T1D pathogenesis. In this study, we investigated the effects of a single bout of vigorous (80% predicted VO2max) intensity exercise on innate cell mobilisation in T1D and control participants. T1D (N=12, mean age 33.2yrs, predicted VO₂max 32.2 ml.kg.min⁻¹, BMI 25.3 kg.m⁻²) and control (N=12, mean age 29.4yrs, predicted VO2 max 38.5 ml.kg.min⁻¹, BMI 23.7 kg.m⁻² male participants completed a 30-minute bout of cycling at 80% predicted VO₂ max in a fasted state. Peripheral blood was collected at baseline, immediately post-exercise, and 1 hour post-exercise. NK cell subsets mobilised during vigorous intensity exercise in both control and T1D participants. However, mature NK cells, defined as the CD56dimCD16bright subset, displayed a lower percentage increase following vigorous intensity exercise in T1D participants (Control: 185.12%, T1D: 97.06%). This blunted mobilisation was specific to early mature NK cells (KIR+) but not later differentiated NK cells (KIR+CD57+). Myeloid lineage subsets mobilised to a similar extent in both control and T1D participants. In conclusion, vigorous exercise mobilises innate immune cells in people with T1D albeit to a different extent to those without T1D. This mobilisation of innate immune cells provides a mechanistic argument to support exercise in people with T1D where it has the potential to improve surveillance for infection and to modulate the autoimmune response to the beta cell.

Impact of glycaemic control on fracture risk in 5368 people with newly diagnosed Type 1 diabetes: a time-dependent analysis

AIMS

To assess whether glycaemic control is associated with a lifelong increased risk of fracture in people with newly diagnosed Type 1 diabetes.

METHODS

People with newly diagnosed Type 1 diabetes between 1 January 1995 and 10 May 2016 were identified in The Health Improvement Network database. Longitudinal HbA_1c measurements from diagnosis to fracture or study end or loss to follow-up were collected. A Cox proportional hazards model with HbA_1c included as a time-dependent variable was fitted to these data.

RESULTS

Some 5368 people with newly diagnosed Type 1 diabetes were included. The estimated adjusted hazard ratio (aHR) for HbA_1c was statistically significant [aHR 1.007; 95% confidence interval (CI) 1.002-1.011 (mmol/mol) and aHR 1.07; 95% CI 1.03-1.12 (%)]. An incremental higher risk of fracture was observed with increasing levels of HbA_1c .

CONCLUSIONS

In people with newly diagnosed Type 1 diabetes, higher HbA_1c is associated with an increased risk for fractures.

Carbohydrate restriction for glycaemic control in Type 2 diabetes: a systematic review and meta-analysis

AIM

To conduct a systematic review and meta-analysis to evaluate the effect of carbohydrate restriction on glycaemic control in Type 2 diabetes.

METHODS

We searched Medline, EMBASE and CINAHL for the period between 1976 and April 2018. We included randomized controlled trials comparing carbohydrate restriction with a control diet which aimed to maintain or increase carbohydrate intake, and that reported HbA_1c as an outcome and reported the amount of carbohydrate consumed during or at the end of the study, with outcomes reported at ≥3 months.

RESULTS

We identified 1402 randomized controlled trials, 25 of which met the inclusion criteria, incorporating 2132 participants for the main outcome. Definitions of low carbohydrate varied among the studies. The pooled effect estimate from meta-analysis was a weighted mean difference of -0.09% [95% CI -0.27, 0.08 (P = 0.30); I² 72% (P <0.001)], suggesting no effect on HbA_1c of restricting the quantity of carbohydrate. A subgroup analysis of diets containing 50-130 g carbohydrate resulted in a pooled effect estimate of -0.49% [95% CI -0.75, -0.23 (P <0.001); I² 0% (P = 0.56)], suggesting a clinically and statistically significant effect on HbA_1c in favour of low-carbohydrate diets in studies of ≤6 months' duration.

CONCLUSIONS

There was no overall pooled effect on HbA_1c in favour of restricting carbohydrate; however, restriction of carbohydrate to 50-130 g per day had beneficial effects on HbA_1c in trials up to 6 months. Future randomized controlled trials should be of >12 months' duration, assess pre-study carbohydrate intake, use recognized definitions of low-carbohydrate diets and examine reasons for non-adherence to prescribed diets in greater detail.

Identical and Nonidentical Twins: Risk and Factors Involved in Development of Islet Autoimmunity and Type 1 Diabetes

OBJECTIVE

There are variable reports of risk of concordance for progression to islet autoantibodies and type 1 diabetes in identical twins after one twin is diagnosed. We examined development of positive autoantibodies and type 1 diabetes and the effects of genetic factors and common environment on autoantibody positivity in identical twins, nonidentical twins, and full siblings.

RESEARCH DESIGN AND METHODS

Subjects from the TrialNet Pathway to Prevention Study (N = 48,026) were screened from 2004 to 2015 for islet autoantibodies (GAD antibody [GADA], insulinoma-associated antigen 2 [IA-2A], and autoantibodies against insulin [IAA]). Of these subjects, 17,226 (157 identical twins, 283 nonidentical twins, and 16,786 full siblings) were followed for autoantibody positivity or type 1 diabetes for a median of 2.1 years.

RESULTS

At screening, identical twins were more likely to have positive GADA, IA-2A, and IAA than nonidentical twins or full siblings (all P < 0.0001). Younger age, male sex, and genetic factors were significant factors for expression of IA-2A, IAA, one or more positive autoantibodies, and two or more positive autoantibodies (all P ≤ 0.03). Initially autoantibody-positive identical twins had a 69% risk of diabetes by 3 years compared with 1.5% for initially autoantibody-negative identical twins. In nonidentical twins, type 1 diabetes risk by 3 years was 72% for initially multiple autoantibody-positive, 13% for single autoantibody-positive, and 0% for initially autoantibody-negative nonidentical twins. Full siblings had a 3-year type 1 diabetes risk of 47% for multiple autoantibody-positive, 12% for single autoantibody-positive, and 0.5% for initially autoantibody-negative subjects.

CONCLUSIONS

Risk of type 1 diabetes at 3 years is high for initially multiple and single autoantibody-positive identical twins and multiple autoantibody-positive nonidentical twins. Genetic predisposition, age, and male sex are significant risk factors for development of positive autoantibodies in twins.

A Type 1 Diabetes Genetic Risk Score Predicts Progression of Islet Autoimmunity and Development of Type 1 Diabetes in Individuals at Risk

OBJECTIVE

We tested the ability of a type 1 diabetes (T1D) genetic risk score (GRS) to predict progression of islet autoimmunity and T1D in at-risk individuals.

RESEARCH DESIGN AND METHODS

We studied the 1,244 TrialNet Pathway to Prevention study participants (T1D patients' relatives without diabetes and with one or more positive autoantibodies) who were genotyped with Illumina ImmunoChip (median [range] age at initial autoantibody determination 11.1 years [1.2-51.8], 48% male, 80.5% non-Hispanic white, median follow-up 5.4 years). Of 291 participants with a single positive autoantibody at screening, 157 converted to multiple autoantibody positivity and 55 developed diabetes. Of 953 participants with multiple positive autoantibodies at screening, 419 developed diabetes. We calculated the T1D GRS from 30 T1D-associated single nucleotide polymorphisms. We used multivariable Cox regression models, time-dependent receiver operating characteristic curves, and area under the curve (AUC) measures to evaluate prognostic utility of T1D GRS, age, sex, Diabetes Prevention Trial-Type 1 (DPT-1) Risk Score, positive autoantibody number or type, HLA DR3/DR4-DQ8 status, and race/ethnicity. We used recursive partitioning analyses to identify cut points in continuous variables.

RESULTS

Higher T1D GRS significantly increased the rate of progression to T1D adjusting for DPT-1 Risk Score, age, number of positive autoantibodies, sex, and ethnicity (hazard ratio [HR] 1.29 for a 0.05 increase, 95% CI 1.06-1.6; P = 0.011). Progression to T1D was best predicted by a combined model with GRS, number of positive autoantibodies, DPT-1 Risk Score, and age (7-year time-integrated AUC = 0.79, 5-year AUC = 0.73). Higher GRS was significantly associated with increased progression rate from single to multiple positive autoantibodies after adjusting for age, autoantibody type, ethnicity, and sex (HR 2.27 for GRS >0.295, 95% CI 1.47-3.51; P = 0.0002).

CONCLUSIONS

The T1D GRS independently predicts progression to T1D and improves prediction along T1D stages in autoantibody-positive relatives.

Influence of pH on wet-synthesis of silver decorated hydroxyapatite nanopowder

Here, effect of solution pH on precipitation of silver decorated hydroxyapatite (Ag-HAp) nano powder during its wet-synthesis was systematically studied. XRD pattern of Ag-HAp nano powder synthesised at pH ranging from 5 to 10 shows that calcium hydrogen phosphate was formed as dominating phase when the solution pH was between 5 and 9 and this phase was gradually transformed into a stable HAp above pH 9. A quantitative analysis of silver amount in Ag-HAp nano powder synthesised at different pH showed that silver can be precipitated to its maximum amount at pH 8 and the further addition of ammonia leads to the formation of a silver-ammonium complex, thereby remaining in the solution. HR-TEM and XPS analysis further confirmed the presence of silver in HAp nanocrystals, synthesised at an optimum pH 9. This trace amount of silver in HAp nano powder showed effective antibacterial activity against Staphylococcus aureus and Escherichia coli. In addition, the cytocompatibility studies carried out on MG63 cells further confirmed the present optimised silver concentration of the Ag-HAp nano powder is well within the toxic limit to be useful in various biomedical applications.

Exercise to preserve β-cell function in recent-onset Type 1 diabetes mellitus (EXTOD) - a randomized controlled pilot trial

AIM

Residual β-cell function is present at the time of diagnosis with Type 1 diabetes. Preserving this β-cell function reduces complications. We hypothesized that exercise preserves β-cell function in Type 1 diabetes and undertook a pilot trial to address the key uncertainties in designing a definitive trial to test this hypothesis.

METHODS

A randomized controlled pilot trial in adults aged 16-60 years diagnosed with Type 1 diabetes within the previous 3 months was undertaken. Participants were assigned to control (usual care) or intervention (exercise consultation every month), in a 1 : 1 ratio for 12 months. The primary outcomes were recruitment rate, drop out, exercise adherence [weeks with ≥ 150 min of self-reported moderate to vigorous physical activity (MVPA)], and exercise uptake in the control group. The secondary outcomes were differences in insulin sensitivity and rate of loss of β-cell function between intervention and control at 6 and 12 months.

RESULTS

Of 507 individuals who were approached, 58 (28 control, 30 intervention) entered the study and 41 completed it. Participants were largely white European males, BMI 24.8 ± 3.8 kg/m² , HbA_1c 75 ± 25 mmol/mol (9 ± 2%). Mean level of objectively measured MVPA increased in the intervention group (mean 243 to 273 min/week) and 61% of intervention participants reached the target of ≥ 150 min/week of self-reported MVPA on at least 42 weeks of the year. Physical activity levels fell slightly in the control group (mean 277 to 235 min of MVPA/week). There was exploratory evidence that intervention group became more insulin sensitive and required less insulin. However, the rate of loss of β-cell function appeared similar between the groups, although the change in insulin sensitivity may have affected this.

CONCLUSION

We show that it is possible to recruit and randomize people with newly diagnosed Type 1 diabetes to a trial of an exercise intervention, and increase and maintain their exercise levels for 12 months. Future trials need to incorporate measures of greater adherence to exercise training targets, and include more appropriate measures of β-cell function. (Clinical Trials Registry No; ISRCTN91388505).

Inpatient electronic prescribing data can be used to identify 'lost' discharge codes for diabetes

AIM

Accurate assessment of missed discharge codes for diabetes is critical for effective planning of hospital diabetes services. We wished to estimate the frequency of missed discharge diagnostic codes for diabetes and the impact missed codes would have on diabetes-related payments to the hospital.

METHODS

We linked Patient Administration System data to the Prescribing Information and Communication System. We defined diabetes as those having a discharge code for diabetes in the Patient Administration System and those on anti-diabetic medication in the Prescribing Information and Communication System. Based on the two sources, we calculated the estimated missed discharge codes for diabetes using the capture-recapture technique. We generated the Healthcare Resource Group for a given admission before and after correction for the missed code to estimate the impact that correction would make on payments to the hospital.

RESULTS

Among the 171 067 admissions linked, 22 412 (13.1%) had a code for diabetes at discharge. An additional 2706 admissions were classified as having diabetes based on prescription data. The capture-recapture technique estimated there were 4588 (2.7% of all admissions) admissions with diabetes missed by current coding, of which 2706 (60%) would be obtained from prescription data. After adding a diabetes diagnostic code, 12.8% of the missed admissions with diabetes resulted in a change to the Healthcare Resource Group tariff code and payment.

CONCLUSION

The use of electronic prescription data is a simple solution to correct for missed discharge diagnostic codes.

Hypoglycaemia is associated with increased length of stay and mortality in people with diabetes who are hospitalized

AIM

To study the length of stay and inpatient mortality of patients with diabetes who had an episode of hypoglycaemia in a non critical care setting at University Hospital Birmingham, UK.

METHODS

Retrospective analysis of routinely available electronic data of 6374 admissions with a recording of either laboratory or point-of-care blood glucose value. Based on the lowest recorded blood glucose values, patients were categorized into a group without hypoglycaemia (> 3.9 mmol/l), a group with mild to moderate hypoglycaemia (2.3-3.9 mmol/l) and a group with severe hypoglycaemic (≤ 2.2 mmol/l). Length of stay and inpatient mortality were compared between the three groups, adjusting for age, gender, ethnicity, deprivation, admission type, use of insulin and modified Charlson co-morbidity score.

RESULTS

There were 148 admissions (2.3%) with severe hypoglycaemia (≤ 2.2 mmol/l), 500 admissions (7.8%) with mild to moderate hypoglycaemia (2.2-3.9 mmol/l) and 5726 admissions with no recorded hypoglycaemic episode (> 3.9 mmol/l). After adjustment, length of stay, when compared with those without a recorded hypoglycaemic episode, was 1.51 (95% CI 1.35-1.68) times higher in the group with blood glucose values of 2.3-3.9 mmol/l and 2.33 (95% CI 1.91-2.84) higher in the group with blood glucose values ≤ 2.2 mmol/l. Adjusted odds ratio of inpatient mortality when compared with the group without hypoglycaemia was 1.62 (95% CI 1.16-2.27) in the group with blood glucose values of 2.3-3.9 mmol/l and 2.05 (95% CI 1.24-3.38) in the group with blood glucose values ≤ 2.2 mmol/l.

CONCLUSION

Hypoglycaemia is associated with increased length of stay and inpatient mortality. Whilst causative evidence is lacking, our data are consistent with the need to avoid hypoglycaemia in our current and continued approach for optimal glycaemic control in people with diabetes admitted to hospital.

What are the health benefits of physical activity in type 1 diabetes mellitus? A literature review

Physical activity improves well-being and reduces the risk of heart disease, cancer and type 2 diabetes mellitus in the general population. In individuals with established type 2 diabetes, physical activity improves glucose and lipid levels, reduces weight and improves insulin resistance. In type 1 diabetes mellitus, however, the benefits of physical activity are less clear. There is poor evidence for a beneficial effect of physical activity on glycaemic control and microvascular complications, and significant risk of harm through hypoglycaemia. Here we review the literature relating to physical activity and health in type 1 diabetes. We examine its effect on a number of outcomes, including glycaemic control, lipids, blood pressure, diabetic complications, well-being and overall mortality. We conclude that whilst there is sufficient evidence to recommend physical activity in the management of type 1 diabetes, it is still unclear as to what form, duration and intensity should be recommended and whether there is benefit for many of the outcomes examined.

Aggressive and devastating neuropathy: the consequence of untreated slow-onset type 1 diabetes

Though type 1 diabetes (T1D) is described to be a disease of acute onset, there is strong evidence for a period of subclinical hyperglycaemia leading up to diagnosis. We describe two clinical cases with a prolonged and insidious onset of T1D, where neurological complications were present at the time of diagnosis. In both, there was an initial rapid and debilitating progression in neurological as well as other microvascular complications, but with a subsequent stabilization in complications over the next few years. These rare and unusual cases illustrate the variable nature of the natural history of T1D as well as its microvascular complications.

Expression and function of the autoimmune regulator (Aire) gene in non-thymic tissue

Educational immune tolerance to self-antigens is induced primarily in the thymus where tissue-restricted antigens (TRAs) are presented to T lymphocytes by cells of the thymic stroma - a process known as central tolerance. The expression of these TRAs is controlled in part by a transcription factor encoded by the autoimmune regulatory (Aire) gene. Patients with a mutation of this gene develop a condition known as autoimmune-polyendocrinopathy-candidiasis-ectodermal-dystrophy (APECED), characterized by autoimmune destruction of endocrine organs, fungal infection and dental abnormalities. There is now evidence for TRA expression and for mechanisms of functional tolerance outside the thymus. This has led to a number of studies examining Aire expression and function at these extra-thymic sites. These investigations have been conducted across different animal models using different techniques and have often shown discrepant results. Here we review the studies of extra thymic Aire and discuss the evidence for its expression and function in both human and murine systems.

Relationship between coronary microvascular dysfunction and cardiac energetics impairment in type 1 diabetes mellitus

BACKGROUND

Asymptomatic subjects with diabetes mellitus have an impaired cardiac energetics status that may play a significant role in the development of heart failure. In the present study, we assessed the role of microvascular dysfunction in the development of impaired cardiac energetics in subjects with type 1 diabetes mellitus.

METHODS AND RESULTS

Twenty-five asymptomatic subjects with type 1 diabetes mellitus (mean age +/-1 SD 33+/-8 years) and 26 age-, sex-, and body mass index-matched healthy control subjects (32+/-8 years old) were recruited into the study. The type 1 diabetes mellitus subjects were divided into 2 age-matched groups (newly diagnosed [<5 years] and longer-duration [>10 years] diabetes) to assess the impact of microvascular disease. All subjects had an echocardiogram and an exercise ECG performed, followed by magnetic resonance spectroscopy and stress magnetic resonance imaging. Compared with healthy control subjects, the phosphocreatine/gamma-ATP ratio was reduced significantly both in subjects with longer-term (2.1+/-0.5 versus 1.5+/-0.4, P<0.000) and newly diagnosed (2.1+/-0.5 versus 1.6+/-0.2, P<0.000) diabetes. The phosphocreatine/gamma-ATP ratio was similar in newly diagnosed diabetes subjects and those with longer-term disease (1.6+/-0.2 versus 1.5+/-0.4, P=0.32). The mean myocardial perfusion reserve index in the longer-term type 1 diabetes mellitus subjects was significantly lower than in healthy control subjects (1.7+/-0.6 versus 2.3+/-0.4, P=0.005). On univariate analysis, there was no significant correlation of phosphocreatine/gamma-ATP ratio with myocardial perfusion reserve index (r=0.21, P=0.26).

CONCLUSIONS

We demonstrate that young subjects with uncomplicated type 1 diabetes mellitus have impaired myocardial energetics irrespective of the duration of diabetes and that the impaired cardiac energetics status is independent of coronary microvascular function. We postulate that impairment of cardiac energetics in these subjects primarily results from metabolic dysfunction rather than microvascular impairment.

Addressing insulin resistance in Type 1 diabetes

Type 1 diabetes is recognised to include an element of insulin resistance. Insulin resistance is an independent risk factor for the development of macro- and microvascular complications of Type 1 diabetes and may also contribute to the development of the disease. This understanding comes at a time when the incidence of Type 1 diabetes appears to be rising and the public health burden from its vascular complications is high. A variety of safe and efficacious manoeuvres are available to redress insulin resistance in Type 2 diabetes. So far however, clinical trials addressing insulin resistance in Type 1 diabetes have been small with only short periods of follow-up. Regardless, these trials have yielded promising results. This review examines the evidence for insulin resistance in the pathophysiology of Type 1 diabetes and its complications, the problems associated with its measurement, and summarizes the trials aimed at reducing insulin resistance in Type 1 diabetes. This includes a meta-analysis of controlled trials of adjuvant metformin in Type 1 diabetes.

Activated T cell subsets in human type 1 diabetes: evidence for expansion of the DR+ CD30+ subpopulation in new-onset disease

An important limitation in T cell studies of human autoimmune (type 1) diabetes is lack of direct access to cells infiltrating the pancreas. We hypothesized that cells recently released from the pancreas into the blood might express a characteristic combination of markers of activation. We therefore examined the recently activated circulating T cell population [CD3+, human leucocyte antigen D-related (HLA-DR+)] using cytokine production and 10 additional subset markers [CD69, CD25, CD122, CD30, CD44v6, CD57, CD71, CCR3 (CD193), CCR5 (CD195) or CXCR3 (CD183)], comparing newly diagnosed adult (ND) (age 18-40 years) patients (n=19) to patients with diabetes for >10 years [long-standing (LS), n=19] and HLA-matched controls (C, n=16). CD3+ DR+ cells were enriched by two-step immunomagnetic separation. No differences in basal or stimulated production of interleukin (IL)-4, IL-10, IL-13 or interferon (IFN)-gamma by CD3+ DR+ enriched cells were observed between the different groups of subjects. However, among the CD3+ DR+ population, significant expansions appeared to be present in the very small CD30+, CD69+ and CD122+ subpopulations. A confirmatory study was then performed using new subjects (ND=26, LS=15), three-colour flow cytometry, unseparated cells and three additional subset markers (CD38, CD134, CD4/CD25). This confirmed the expansion of the CD3+ DR+ CD30+ subpopulation in ND subjects. We conclude that a relative expansion in the T cell subpopulation with the activated phenotype CD3+ DR+ CD30+ is seen in the peripheral blood of subjects with newly diagnosed type 1 diabetes. This subpopulation represents less than 0 x 7% of circulating T cells and may provide a rich source of disease-specific T cells that can be isolated from blood.

Insulin resistance is a risk factor for progression to type 1 diabetes

AIMS/HYPOTHESIS

Glucose homeostasis is determined by an interplay between insulin secretion and insulin action. In type 1 diabetes, autoimmune destruction of pancreatic beta cells leads to impaired insulin secretion. However, the contribution of impaired insulin action (insulin resistance) to the development of type 1 diabetes has received little attention. We investigated whether insulin resistance was a risk factor for progression to type 1 diabetes.

METHODS

Islet-antibody-positive first-degree relatives of type 1 diabetes probands were followed for 4.0 years (median). Insulin secretion was measured as first-phase insulin response (FPIR) to intravenous glucose. Insulin resistance was estimated by homeostasis model assessment of insulin resistance (HOMA-R). We compared subjects who progressed (n=43) and subjects who did not progress (n=61) to diabetes, including 21 pairs matched for age, sex, islet antibodies and FPIR.

RESULTS

Progressors had higher insulin resistance relative to insulin secretion at baseline (median HOMA-R : FPIR 0.033 vs 0.013, p<0.0001). According to Cox proportional hazards analysis, islet antibody number, FPIR, fasting plasma glucose, fasting serum insulin, HOMA-R and log(HOMA-R : FPIR) were each predictive of progression to diabetes. However, log(HOMA-R : FPIR) (hazard ratio 2.57 per doubling, p<0.001) was the only metabolic variable independently associated with progression. In the matched comparison, progressors had higher fasting glucose, fasting insulin, HOMA-R and HOMA-R : FPIR, both at baseline and during the follow-up pre-clinical phase.

CONCLUSIONS/INTERPRETATION

Relatives positive for islet antibodies who progress most rapidly to diabetes have a subtle disturbance of insulin-glucose homeostasis years before the onset of symptoms, distinguished by greater insulin resistance for their level of insulin secretion. Taking steps to reduce this insulin resistance could therefore delay the development of type 1 diabetes.

Naturally processed and presented epitopes of the islet cell autoantigen IA-2 eluted from HLA-DR4

During immune responses, antigen-presenting cells (APCs) process antigens and present peptide epitopes complexed with human leukocyte antigen (HLA) molecules. CD4 cells recognize these naturally processed and presented epitopes (NPPEs) bound to HLA class II molecules. Epitope identification is important for developing diagnostic and therapeutic tools for immune-mediated diseases and providing insight into their etiology, but current approaches overlook effects of natural processing on epitope selection. We have developed a technique to identify NPPEs using mass spectrometry (MS) after antigen is targeted onto APCs using a lectin-based antigen delivery system (ADS). We applied the technique to identify NPPEs of the intracellular domain of the type 1 diabetes mellitus-associated (type 1 DM-associated) autoantigen insulinoma-associated-2 (IA-2ic), presented by HLA-DR4 (0401). IA-2ic-derived NPPEs eluted from HLA-DR4 constitute 6 sets of peptides nested around distinct core regions. Synthetic peptides based on these regions bind HLA-DR4 and elicit primary T-cell proliferation frequently in HLA-DR4-positive type 1 DM patients, but rarely in non-HLA-DR4 patients, and in none of the HLA-DR4 nondiabetic controls we tested. This flexible, direct approach identifies an HLA allele-specific map of NPPEs for any antigen, presented by any HLA class II molecule. This method should enable a greater understanding of epitope selection and lead to the generation of sensitive and specific reagents for detecting autoreactive T cells.