Insulin intervention to preserve beta cells in slowly progressive insulin-dependent (type 1) diabetes mellitus

Comparison of positive rates between glutamic acid decarboxylase antibodies and ElisaRSR™ 3 Screen ICA™ in recently obtained sera from patients who had been previously diagnosed with slowly progressive type 1 diabetes

AIMS/INTRODUCTION

This study aimed to compare the positivity rates of glutamic acid decarboxylase autoantibodies (GADA) and ElisaRSR™ 3 Screen ICA™ (3 Screen ICA), a newly developed assay for the simultaneous measurement of GADA, insulinoma-associated antigen-2 autoantibodies (IA-2A), and zinc transporter 8 autoantibodies (ZnT8A), in recently obtained sera from patients who had been previously diagnosed with slowly progressive type 1 diabetes (SPIDDM).

MATERIALS AND METHODS

We enrolled 53 patients with SPIDDM who were positive for GADA at the diagnosis and 98 non-diabetic individuals, and investigated the diagnostic accuracy of the 3 Screen ICA (cutoff index ≥30 units) compared with that of GADA. In addition, we compared the clinical characteristics of patients with SPIDDM who were negative or positive on 3 Screen ICA.

RESULTS

The positivity rates of 3 Screen ICA, GADA, IA-2A, and ZnT8A were 88.7, 86.8, 24.5, and 13.2%, respectively. The respective sensitivity, specificity, and positive and negative predictive values for SPIDDM were 88.7, 100, 100, and 94.2% by 3 Screen ICA and 86.8, 100, 100.0, and 93.3% by GADA. There were no significant differences in age at onset, duration of diabetes, body mass index, glycated hemoglobin and C-peptide levels, and the prevalence of autoimmune thyroiditis between patients with SPIDDM who were positive or negative on 3 Screen ICA. However, the prevalence of insulin users was significantly higher in those who were positive than in those who were negative on 3 Screen ICA.

CONCLUSIONS

Similar to GADA, 3 Screen ICA may be a useful diagnostic tool for detecting patients with SPIDDM.

Latent autoimmune diabetes in adults: a focus on β-cell protection and therapy

Latent autoimmune diabetes in adults (LADA) is a heterogeneous disease sharing some phenotypic, genetic, and immunological features with both type 1 and 2 diabetes. Patients with LADA have a relatively slow autoimmune process and more residual islet β-cell function at onset, allowing a time window to protect residual islet β cells and delay or inhibit disease progression. It is crucial to discover various heterogeneous factors affecting islet β-cell function for precise LADA therapy. In this review, we first describe the natural history of LADA. Thereafter, we summarize β-cell function-related heterogeneous factors in LADA, including the age of onset, body mass index, genetic background, and immune, lifestyle, and environmental factors. In parallel, we evaluate the impact of current hypoglycemic agents and immune intervention therapies for islet β-cell protection. Finally, we discuss the opportunities and challenges of LADA treatment from the perspective of islet β-cell function protection.

Improved insulin sensitivity with sodium-glucose cotransporter 2 inhibitor treatment in a patient with slowly progressive type 1 diabetes mellitus with metabolic syndrome: a case report

We herein report the clinical course of a 56-year-old Japanese patient with slowly progressive type 1 diabetes mellitus, metabolic syndrome, non-alcoholic fatty liver disease, and severe insulin resistance. The patient's intravenous glucose tolerance test indicated marked reductions in insulin sensitivity and endogenous insulin secretion. Accordingly, administration of ipragliflozin l-proline, a sodium-glucose cotransporter 2 inhibitor, promoted improvements in insulin sensitivity and blood glucose levels, as well as a decrease in visceral fat, improvement in dyslipidemia, and decrease in hepatic lipid content, suggesting the potential efficacy of sodium-glucose cotransporter 2 inhibitors for obese patients with type 1 diabetes mellitus exhibiting insulin resistance.

Adult-onset autoimmune diabetes: current knowledge and implications for management

Adult-onset autoimmune diabetes is a heterogeneous disease that is characterized by a reduced genetic load, a less intensive autoimmune process and a mild metabolic decompensation at onset compared with young-onset type 1 diabetes mellitus (T1DM). The majority of patients with adult-onset autoimmune diabetes do not require insulin treatment for at least 6 months after diagnosis. Such patients are defined as having latent autoimmune diabetes in adults (LADA), which is distinct from classic adult-onset T1DM. The extensive heterogeneity of adult-onset autoimmune diabetes is apparent beyond the distinction between classic adult-onset T1DM and LADA. LADA is characterized by genetic, phenotypic and humoral heterogeneity, encompassing different degrees of insulin resistance and autoimmunity; this heterogeneity is probably a result of different pathological mechanisms, which have implications for treatment. The existence of heterogeneous phenotypes in LADA makes it difficult to establish an a priori treatment algorithm, and therefore, a personalized medicine approach is required. In this Review, we discuss the current understanding and gaps in knowledge regarding the pathophysiology and clinical features of adult-onset autoimmune diabetes and highlight the similarities and differences with classic T1DM and type 2 diabetes mellitus.

Latent autoimmune diabetes in adults (LADA) in Asian and European populations

Diabetes mellitus is a chronic disorder caused by relative or absolute insulin deficiency and characterized by chronic hyperglycaemia. It is expected that by year 2025, 80% of all type 2 diabetic patients will be living in developing or low- and middle-income countries. Among Asians, there has been an overall increase in abdominal obesity; however, the risk of diabetes in these populations starts at much lower body mass index as compared to Caucasians. A significant proportion of diabetic patients with adult-onset, initially nonrequiring insulin treatment, have diabetes-associated autoantibodies in their sera. A new subclass of diabetes with the designation of latent autoimmune diabetes of adult-onset (LADA) has been proposed for this category of subjects. Studies have demonstrated that patients with autoimmune diabetes, characterized by the presence of glutamic decarboxylase autoantibodies display a different clinical phenotype from classical type 2 diabetes without glutamic decarboxylase autoantibodies. This subset of phenotypic type 2 diabetes subjects with islet autoantibodies tend to have sulphonylurea failure and need insulin treatment earlier in the disease process. Diagnosing LADA at an initial stage will be important so that insulin can be initiated earlier, facilitating improved glycemic control sooner as well as the preservation of residual beta-cell function in adult-onset autoimmune diabetes. Because of differences in dietary habits, environmental factors, and phenotypic characteristics between European and Asian populations, there may be heterogeneity in the prevalence and other characteristics of LADA in these two populations.

Development of a novel ultrasensitive enzyme immunoassay for human glutamic acid decarboxylase 65 antibody

Background

We developed a novel, ultrasensitive enzyme immunoassay (immune complex transfer enzyme immunoassay) for determination of glutamic acid decarboxylase autoantibody concentrations in serum samples from patients with type 2 diabetes.

Methods

We developed an immune complex transfer enzyme immunoassay for glutamic acid decarboxylase autoantibody and measured glutamic acid decarboxylase autoantibody from 22 patients with type 1 diabetes, 29 patients with type 2 diabetes, and 32 healthy controls.

Results

A conventional ELISA kit identified 10 patients with type 1 diabetes and one patient with type 2 diabetes as glutamic acid decarboxylase autoantibody positive, whereas 15 patients with type 1 diabetes and six patients with type 2 diabetes were identified as glutamic acid decarboxylase autoantibody positive using immune complex transfer enzyme immunoassay.

Conclusions

Immune complex transfer enzyme immunoassay is a highly sensitive and specific assay for glutamic acid decarboxylase autoantibody and might be clinically useful for diabetic onset prediction and early diagnosis.

Evaluation of insulin secretion and sensitivity in a patient with slowly progressive type 1 diabetes mellitus

We herein report the case of a patient with slowly progressive type 1 diabetes and insulin independence lasting for >10 years despite the detection of continuously elevated glutamic acid decarboxylase autoantibody titers. We monitored the patient's clinical course and analyzed his endogenous insulin secretion and sensitivity using an intravenous glucose tolerance test (IVGTT) and oral glucose tolerance test (OGTT). His body mass index remained at approximately 22, while his serum C-peptide immunoreactivity level gradually decreased. The level of insulin secretion was significantly higher on the OGTT than the IVGTT. The patient's insulin sensitivity was within the normal limits. These results suggest that maintaining a lifestyle sufficient to preserve insulin secretion and/or normal insulin sensitivity is important and that β-cell responsiveness to incretins may, in part, contribute to insulin independence.

Latent autoimmune diabetes in the adults (LADA) in Asia: from pathogenesis and epidemiology to therapy

Diabetes mellitus is a metabolic disorder resulting from a defect in insulin secretion, insulin action or both. An effect of this process is chronic hyperglycaemia with disorder of carbohydrate, fat and protein metabolism and with long-term complications of diabetes including retinopathy, nephropathy and neuropathy. Latent autoimmune diabetes in adults (LADA) is a type of autoimmune diabetes that resembles Type 1 diabetes (T1D), however, it shows a later onset and slower progression towards insulin necessity. Epidemiological studies suggest that LADA may account for 2-12% of all cases of diabetes in adult population. The epidemiology and phenotypic characteristics of LADA may vary between Caucasian and Asian diabetic patients as lifestyle, food habits and body mass index differ between these two populations. Data on LADA from population-based studies in Asia are sparse and only few studies have looked at it. A number of attractive therapeutic interventions may be envisaged for prevention of beta-cell loss in LADA, including hypoglycaemic and immunomodulatory agents. Because the autoimmune process in LADA seems to be slower than in childhood T1D, there is a wider window of opportunities for intervention. In deciding the best therapeutic approach, features of LADA should guide therapy including presence of other comorbidities that may influence the therapeutic choice.

Interventions for latent autoimmune diabetes (LADA) in adults

BACKGROUND

Latent autoimmune diabetes in adults (LADA) is a slowly developing type 1 diabetes.

OBJECTIVES

To compare interventions used for LADA.

SEARCH STRATEGY

Studies were obtained from searches of electronic databases, supplemented by handsearches, conference proceedings and consultation with experts. Date of last search was December 2010.

SELECTION CRITERIA

Randomised controlled trials (RCT) and controlled clinical trials (CCT) evaluating interventions for LADA or type 2 diabetes with antibodies were included.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data and assessed risk of bias. Studies were summarised using meta-analysis or descriptive methods.

MAIN RESULTS

Searches identified 13,306 citations. Fifteen publications (ten studies) were included, involving 1019 participants who were followed between three months to 10 years (1060 randomised). All studies had a high risk of bias. Sulphonylurea (SU) with insulin did not improve metabolic control significantly more than insulin alone at three months (one study, n = 15) and at 12 months (one study, n = 14) of treatment and follow-up. SU (with or without metformin) gave poorer metabolic control compared to insulin alone (mean difference in glycosylated haemoglobin A1c (HbA1c) from baseline to end of study, for insulin compared to oral therapy: -1.3% (95% confidence interval (CI) -2.4 to -0.1; P = 0.03, 160 participants, four studies, follow-up/duration of therapy: 12, 30, 36 and 60 months; however, heterogeneity was considerable). In addition, there was evidence that SU caused earlier insulin dependence (proportion requiring insulin at two years was 30% in the SU group compared to 5% in conventional care group (P < 0.001); patients classified as insulin dependent was 64% (SU group) and 12.5% (insulin group, P = 0.007). No intervention influenced fasting C-peptide, but insulin maintained stimulated C-peptide better than SU (one study, mean difference 7.7 ng/ml (95% CI 2.9 to 12.5)). In a five year follow-up of GAD65 (glutamic acid decarboxylase formulated with aluminium hydroxide), improvements in fasting and stimulated C-peptide levels (20 μg group) were maintained after five years. Short term (three months) follow-up in one study (n = 74) using Chinese remedies did not demonstrate a significant difference in improving fasting C-peptide levels compared to insulin alone (0.07 µg/L (95% CI -0.05 to 0.19). One study using vitamin D with insulin showed steady fasting C-peptide levels in the vitamin D group but declining fasting C-peptide levels (368 to 179 pmol/L, P = 0.006) in the insulin alone group at 12 months follow-up. Comparing studies was difficult as there was a great deal of heterogeneity in the studies and in their selection criteria. There was no information regarding health-related quality of life, complications of diabetes, cost or health service utilisation, mortality and limited evidence on adverse events (studies on oral agents or insulin reported no adverse events in terms of severe hypoglycaemic episodes).

AUTHORS' CONCLUSIONS

Two studies show SU leading to earlier insulin dependence and a meta-analysis of four studies with considerable heterogeneity showed poorer metabolic control if SU is prescribed for patients with LADA compared to insulin. One study showed that vitamin D with insulin may protect pancreatic beta cells in LADA. Novel treatments such as GAD65 in certain doses (20 μg) have been suggested to maintain fasting and stimulated C-peptide levels. However, there is no significant evidence for or against other lines of treatment of LADA.

Frequency of the anti-glutamic acid decarboxylase immunological marker in patients with diabetes duration longer than three years in southern Brazil

CONTEXT AND OBJECTIVE

The anti-GAD (glutamic acid decarboxylase) antibody is considered to be an important marker for type 1 diabetes mellitus (DM1), with frequency that varies depending on the population studied and the duration of the disease. Therefore, the aim of this study was to determine the frequency of this autoantibody in a group of patients in southern Brazil with DM1 that had been diagnosed more than three years previously.

DESIGN AND SETTING

Analytical cross-sectional study with a control group conducted at the Biomedicine Laboratory of Universidade Feevale.

METHODS

This study was conducted between June 2007 and December 2008, and 109 individuals were enrolled during this period. Fifty-eight were DM1 patients and 51 were individuals free from DM1 and without any history of diabetes, who constituted the control group.

RESULTS

In the DM1 group, the mean age was 27 ± 1.7 years and 50% were men. The mean fasting blood glucose in the DM1 group was 208 ± 15 mg/dl and mean HbA1c (glycosylated hemoglobin) was 8.7 ± 0.25%. In the control group, the mean fasting blood glucose and HbA1c were 82 mg/dl and 5.0% respectively. Thirty-seven individuals with DM1 (63.8%) were positive for anti-GAD, and this proportion was significantly larger than in the control group.

CONCLUSIONS

These results show the high prevalence of anti-GAD in the population of diabetic patients in southern Brazil, thus indicating that the antibody was still present a long time after the disease had been diagnosed.

The over 50 year clinical course of a patient with slowly progressive type 1 diabetes (SPIDDM)

Type 1 diabetic patients who have endured their condition for prolonged periods are not uncommon, but there are few well-documented cases of type 2 diabetic patients with duration of over fifty years. In the present case study, we analyzed the history of a diabetic patient whose duration was 53 years. Her case was consequently diagnosed not as the common type 2 diabetes, but as the slowly progressive type 1 diabetes (SPIDDM) identified by Japanese medical researchers. The patient, now 73 years old, was first diagnosed with diabetes in 1953 when she was 17 years of age and started insulin injections. In 1962 she was referred to our hospital, and two years later she vaginally delivered a healthy baby (birth weight 3100 g) at the 40(th) week of gestation. She was the first case of a diabetic mother delivering an infant treated at Tokyo Women's Medical College Hospital. Her data shows that her C-peptide responses by meal tolerance test in 1978 was at least partly preserved though it decreased year by year. Her anti-GAD antibody was found to be positive in 2000 and remained so in 2009. This leads us to conclude that the etiology of her SPIDDM was most likely has insulin secretion exhaustion.

Latent autoimmune diabetes in adults

CONTEXT

Autoantibodies that are reactive to islet antigens are present at the time of diagnosis in most patients with type 1 diabetes. Additionally, approximately 10% of phenotypic type 2 diabetic patients are positive for at least one of the islet autoantibodies, and this group is often referred to as "latent autoimmune diabetes in adults (LADA)." These patients share many genetic and immunological similarities with type 1 diabetes, suggesting that LADA, like type 1 diabetes, is an autoimmune disease. However, there are differences in autoantibody clustering, T cell reactivity, and genetic susceptibility and protection between type 1 diabetes and LADA, implying important differences in the underlying disease processes.

EVIDENCE ACQUISITION AND SYNTHESIS

In this clinical review, we will summarize the current understanding of LADA based on the MEDLINE search of all peer-reviewed publications (original articles and reviews) on this topic between 1974 and 2009.

CONCLUSIONS

In LADA, diabetes occurs earlier in the beta-cell-destructive process because of the greater insulin resistance. Complexities arise also because of variable definitions of LADA and type 1 diabetes in adults. As immunomodulatory therapies that slow or halt the type 1 diabetes disease process are discovered, testing these therapies in LADA will be essential.

The role of immunomodulation therapy in autoimmune diabetes

Type 1 diabetes (T1DM) is characterized by loss of virtually all endogenous insulin secretion. If residual insulin secretion is preserved, this will lead to improved metabolic balance, less acute and late complications, improved quality of life, and, in case of pronounced improvement of residual insulin secretion, complete remission and even cure of the disease. Immune suppression or immune modulation have been demonstrated as a proof of principle to stop/decrease the destructive process and thereby preserve beta-cell function. Several methods to save residual beta-cell function have been tried for more than three decades with little or no evidence of efficacy. Positive effects have been seen mainly in adult patients but have been minimal or absent in children with diabetes. Furthermore, the safety of these immune interventions and/or their benefit to risk relationships have not been found to justify clinical use. More specific immune modulation with anti-CD3 monoclonal antibodies has resulted in more encouraging postponement of C-peptide decline, but with frequent and serious adverse effects. Still more promising are the autoantigen therapies, of which glutamic acid decarboxylase (GAD) vaccination has shown significant preservation of residual insulin secretion in 10-18-year-old type 1 diabetes patients with recent onset. Efficacy was most impressive in the subgroup of patients with diabetes of short duration (<3 months). The treatment was simple, well tolerated, and showed no treatment-related adverse events. If these results can be confirmed, there is a realistic hope that GAD vaccination, perhaps in combination with vaccinations with other autoantigens and/or other therapies, will result in remission for some patients. The prospects of cure and prevention of T1DM will become less remote.

Latent autoimmune diabetes in an adult

We report a case of latent autoimmune diabetes in adults (LADA), also known as slowly progressive type 1 diabetes (SPT1D), followed up for changes, including reactivity to the GAD65 antibody epitope for the 9-year period from impaired glucose tolerance (IGT) to the insulin-dependent stage (IDDM). This 69-year-old male was identified as having IGT by health checkup in 1998. As he was GAD65-positive (high titer), we initiated close clinical follow-up. In 2003, a 75-g oral glucose tolerance test showing a diabetic pattern confirmed that he had progressed to diabetes. During this period, fasting plasma glucose remained within normal range and insulin secretion was unchanged compared to that at the time of IGT diagnosis. His fasting plasma glucose and HbA1c levels began to increase in 2004 and serum C-peptide began to decrease in 2005. Insulin treatment was started in August 2006. GAD65 antibody titer was high (13900 U/ml) in 1998 and has remained high throughout follow-up. The patient's GAD65 antibodies were initially directed to the b96.11-defined epitope only, recognized as an indicator of T1D-like pathogenesis in our former study. During follow-up, he developed reactivity to more epitopes (MICA-3 and MICA-4, DPC, and DPA). The course of this case suggests that the b96.11-defined epitope is important for distinguishing LADA patients who progress to IDDM from those who do not and that epitope maturation is restricted to LADA patients who progress to IDDM, an observation similar to that in children at risk for developing typical IDDM.

Diabetes classification: grey zones, sound and smoke: Action LADA 1

Diseases gain identity from clinical phenotype as well as genetic and environmental aetiology. The definition of type 1 diabetes is clinically exclusive, comprising patients who are considered insulin dependent at diagnosis, whilst the definition of type 2 diabetes is inclusive, only excluding those who are initially insulin dependent. Ketosis-prone diabetes (KPD) and latent autoimmune diabetes in adults (LADA) are each exclusive forms of diabetes which are, at least initially, clinically distinct from type 2 diabetes and type 1 diabetes, and each have a different natural history from these major types of diabetes.KPD can be diagnosed unequivocally as diabetes presenting with the categorical clinical feature, ketoacidosis. In contrast, LADA can be diagnosed by the co-occurrence of three traits, not one of which is categorical or exclusive to the condition: adult-onset non-insulin-requiring diabetes, an islet autoantibody such as glutamic acid decarboxylase autoantibodies (GADA) or cytoplasmic islet cell autoantibodies (ICA), and no need for insulin treatment for several months post-diagnosis. But while some would split diabetes into distinct subtypes, there is a strong case that these subtypes form a continuum of varying severity of immune and metabolic dysfunction modified by genetic and non-genetic factors. This article discusses the nature of disease classification in general, and KPD and LADA in particular, emphasizing the potential value and pitfalls in classifying diabetes and suggesting a need for more research in this area.

Randomized, controlled, parallel-group prospective study to investigate the clinical effectiveness of early insulin treatment in patients with latent autoimmune diabetes in adults

BACKGROUND

Latent autoimmune diabetes in adults [LADA] is a type 1 diabetes that is slowly developing. This means many people are treated as having type 2 diabetes at diagnosis as they are adults who are not immediately insulin dependent. LADA can be distinguished from type 2 diabetes by antibody tests. Patients who are antibody positive have an autoimmune reaction which is similar to that of type 1 diabetes and is not found in type 2 diabetes. We would like to examine the best way of treating LADA in the early phase of the conditions, with tablets (similar to type 2 diabetes) or with insulin (similar to type 1 diabetes).

METHODS/DESIGN

This is an open parallel group prospective randomised trial. Participants need to have a GAD antibody test results of 101 WHO units or more and a diagnosis of diabetes not requiring insulin at diagnosis. Participants will need to have been diagnosed within 12 months and not treated with insulin at study entry. They will be randomised to receive either insulin (NovoMix 30) or tablets (diet treated followed by metformin followed by glitazone (with or without metformin) followed by insulin). Primary outcome assessment will be for change in HbA1c and change in fasting C-peptide over 24 months. Secondary outcome measures will include Quality of life, GAD antibody levels, adverse events, inflammatory markers, insulin resistance, and markers of the metabolic syndrome.

DISCUSSION

This study seeks the best treatment for early LADA in terms of maintaining glycaemic control and maintaining natural insulin production.

TRIAL REGISTRATION

ISRCTN63815121.

Routine glutamic acid decarboxylase autoantibody (GADA) testing: patients' perspective

BACKGROUND

Latent autoimmune diabetes in adults (LADA) is a form of type 1 diabetes which in the UK is often diagnosed and treated as type 2 diabetes (T2D). People with LADA show slow progression to insulin dependence and can be distinguished from T2D by blood tests for glutamic acid decarboxylase autoantibodies (GADA). Aims. This study explores the views and experiences of patients who are newly diagnosed with LADA, with particular reference to (i) routine GADA testing; (ii) whether this diagnosis has any influence on the self-management of their diabetes; and (iii) the information needs of patients newly diagnosed with LADA.

METHODS

Ten consecutive patients newly diagnosed with LADA (GADA positive) were invited to participate in individual qualitative semi-structured interviews. Their views and experiences were analysed into codes and categories, using a constant comparative method.

FINDINGS

Participants supported routine GADA testing in all patients with diabetes because the provision of a correct diagnosis has an empowering effect on patients, as it encourages the consideration of treatment options early on in the condition. Participants preferred to rely on future Hba(1c) levels and their doctor's opinion to determine a change in treatment to insulin. Some participants had difficulty distinguishing between the different types of diabetes, including LADA. Others needed to ask questions about LADA in addition to written information.

CONCLUSIONS

Participants were supportive of routine GADA testing, would prefer not to start insulin immediately following a diagnosis of LADA and needed to discuss treatment options with health professionals who were knowledgeable on LADA.

Insulin intervention in slowly progressive insulin-dependent (type 1) diabetes mellitus

OBJECTIVE

We tested the hypothesis that insulin therapy rather than sulfonylurea (SU) treatment is preferable to reverse or preserve beta-cell function among patients with slowly progressive insulin-dependent (type 1) diabetes (SPIDDM) or latent autoimmune diabetes in adults.

METHODS

This multicenter, randomized, nonblinded clinical study screened 4089 non-insulin-dependent diabetic patients for glutamic acid decarboxylase autoantibodies (GADAb). Sixty GADAb-positive non-insulin-requiring diabetic patients with a 5-yr duration or shorter of diabetes were assigned to either the SU group (n = 30) or the insulin group (n = 30). Serum C-peptide responses to annual oral glucose tolerance tests were followed up for a mean of 57 months. The primary endpoint was an insulin-dependent state defined by the sum of serum C-peptide values during the oral glucose tolerance test (SigmaC-peptide) less than 4 ng/ml (1.32 nmol/liter).

RESULTS

The progression rate to an insulin-dependent state in the insulin group (three of 30, 10%) was lower than that in the SU group (13 of 30, 43%; P = 0.003, log-rank). Longitudinal analysis demonstrated that SigmaC-peptide values were better preserved in the insulin group than in the SU group. Multiple regression analysis demonstrated that insulin treatment, a preserved C-peptide response, and a low GADAb titer at entry were independent factors in preventing progression to an insulin-dependent state. Subgroup analysis suggested that insulin intervention was highly effective for SPIDDM patients with high GADAb titers [> or =10 U/ml (180 World Health Organization U/ml)] and preserved beta-cell function [SigmaC-peptide > or = 10 ng/ml (3.31 nmol/liter)] at entry. No severe hypoglycemic episodes occurred during the study.

CONCLUSIONS

Insulin intervention to preserve beta-cell function is effective and safe for patients with SPIDDM or latent autoimmune diabetes in adults.

Latent autoimmune diabetes in adults (LADA): usefulness of anti-GAD antibody titers and benefit of early insulinization

OBJECTIVE

To determine the clinical and laboratory parameters and the progression to insulin requirement in two groups of LADA patients separated according to GADA titers, and to evaluate the benefit of early insulinization in patients at high risk of premature beta-cell failure (high GADA titers).

METHODS

Among the diabetic adults seen at our service and screened for GADA at diagnosis, 54 were diagnosed with LADA and classified as having low (> 1 U/ml and < 17.2 U/ml) or high (> 17.2 U/ml) GADA titers. Fifty-four patients with type 2 diabetes (GADA-) were selected for comparison. In addition, 24 patients who had GADA titers > 20 U/ml and who were not initially insulinized were compared to 16 patients who were insulinized at diagnosis.

RESULTS

Insulin resistance was higher in the GADA- group, followed by patients with low GADA titers. BMI and the frequency of arterial hypertension, elevated triglycerides and reduced HDL cholesterol were lower in the high GADA+ group, with no difference between the GADA- or low GADA+ groups. The high GADA+ group showed a greater reduction and lower levels of C-peptide and required insulin earlier during follow-up. Patients with GADA titers > 20 U/ml and insulinized early presented no significant variation in C-peptide levels, had better glycemic control and required a lower insulin dose than patients who were insulinized later.

CONCLUSION

We agree that patients with LADA should be differentiated on the basis of GADA titers and that patients with GADA titers > 20 U/ml benefit from early insulinization.

Diabetes and diarrhea in an elderly woman

Between 5 and 10% of adults initially diagnosed with type 2 diabetes mellitus.(DM) actually have adult-onset autoimmune diabetes. Given the large number of patients diagnosed with DM type 2, the entity called latent autoimmune diabetes in adults (LADA) by some authors could represent half of all diabetics with type 1A diabetes. We report the case of a 75-year-old woman, with a history of brittle diabetes and irritable bowel syndrome, who was finally diagnosed with autoimmune diabetes and celiac disease.

Anti-thyroid peroxidase antibody, IA-2 antibody, and fasting C-peptide levels predict beta cell failure in patients with latent autoimmune diabetes in adults (LADA)--a 5-year follow-up of the Ehime study

OBJECTIVE

To clarify the natural course and factors involved in beta cell failure in Japanese latent autoimmune diabetes in adults (LADA) patients.

RESEARCH DESIGN AND METHODS

Insulin secretion in 57 LADA patients identified from among 4980 adult-onset diabetic patients in a hospital-based Ehime study were examined over a 5-year period. Postprandial serum C-peptide levels below 0.33 nmol/l were defined as beta cell failure. The involvement of clinical and immunological factors in the progression to beta cell failure were evaluated.

RESULTS

Forty-two of the fifty-seven LADA patients completed the 5-year follow-up. Eleven (26.2%) required insulin treatment and five (11.9%) progressed to beta cell failure. A Cox regression analysis revealed that positive anti-thyroid peroxidase antibody (TPOAb) and insulinoma-associated protein 2 (IA-2Ab) were associated with the need for insulin treatment (p<0.05 and p<0.01, respectively). Positive TPOAb, anti-thyroglobulin antibody (TGAb), IA-2 antibody (p<0.01 for each), and lower serum fasting C-peptide levels (p<0.05) were contributors to the progression to beta cell failure. Involvement of type 1 diabetes susceptible HLA class II genes was not evident.

CONCLUSIONS

Japanese LADA patients are a heterogeneous population. In addition to IA-2 antibody, presence of TPOAb and fasting C-peptide level could indicate an oncoming deterioration of beta cell function.

Diabetes auto-imune latente do adulto ou diabetes melito tipo 2 magro?

A prevalência do diabetes auto-imune latente do adulto (LADA) varia em virtude da população estudada, dos critérios usados e dos anticorpos avaliados. Em 256 pacientes com menos de 25 anos, encontramos 26 (10,2%) com anticorpos anti-GAD (GADA) positivos, dos quais 16 (6,3%) evoluíram sem necessidade de insulina inicialmente. Embora exista controvérsias, sugere-se como critérios diagnósticos de LADA: idade entre 25 e 65 anos; ausência de cetoacidose ou hiperglicemia sintomática no diagnóstico ou imediatamente após, sem necessidade de insulina por 6 a 12 meses; e presença de auto-anticorpos (especialmente GADA). A auto-imunidade e a resistência insulínica coexistem no LADA, e a contribuição desses fatores parece estar refletida nos títulos de GADA. Um subgrupo similar aos diabéticos tipo 2, fenotipicamente e na progressão para necessidade de insulina, parece ser melhor identificado pela presença de baixos títulos de GADA, sobretudo isolados. Por outro lado, indivíduos com altos títulos de GADA e múltiplos anticorpos apresentam fenótipo mais próximo do diabetes melito do tipo 1 (DM1) clássico e são de maior risco para falência prematura das células-beta. Comparados aos diabéticos GADA-negativos, pacientes com LADA apresentam maior prevalência de outros auto-anticorpos (anti-TPO, anti-21-hidroxilase e associados à doença celíaca) e maior freqüência de genótipos e haplótipos de risco para DM1. Pacientes com altos títulos de GADA podem ser beneficiados, retardando a falência das células-beta, com a insulinização precoce e evitando-se o uso de sulfoniluréias. Em oposição, pacientes com baixos títulos de GADA aparentemente não teriam prejuízos em serem conduzidos da mesma forma que pacientes portadores de diabetes melito tipo 2 (DM2) (GADA-negativos).

The islet autoantibody titres: their clinical relevance in latent autoimmune diabetes in adults (LADA) and the classification of diabetes mellitus

Latent autoimmune diabetes in the adult (LADA) is a slowly progressive form of autoimmune diabetes, characterized by diabetes-associated autoantibody positivity. A recent hypothesis proposes that LADA consists of a heterogeneous population, wherein several subgroups can be identified based on their autoimmune status. A systematic review of the literature was carried out to appraise whether the clinical characteristics of LADA patients correlate with the titre and numbers of diabetes-associated autoantibodies. We found that the simultaneous presence of multiple autoantibodies and/or a high-titre anti-glutamic acid decarboxylase (GAD)--compared with single and low-titre autoantibody--is associated with an early age of onset, low fasting C-peptide values as a marker of reduced pancreatic B-cell function, a high predictive value for future insulin requirement, the presence of other autoimmune disorders, a low prevalence of markers of the metabolic syndrome including high body mass index, hypertension and dyslipidaemia, and a high prevalence of the genotype known to increase the risk of Type 1 diabetes. We propose a more continuous classification of diabetes mellitus, based on the finding that the clinical characteristics gradually change from classic Type 1 diabetes to LADA and finally to Type 2 diabetes. Future studies should focus on determining optimal cut-off points of anti-GAD for differentiating clinically relevant diabetes mellitus subgroups.

Insulin administration may trigger pancreatic beta-cell destruction in patients with type 2 diabetes

Insulin administration causes various types of immune response to insulin. However, there have been no reports that insulin administration triggers pancreatic beta-cell destruction in diabetic patients. We evaluated three patients who had suffered from type 2 diabetes or impaired glucose tolerance for 5-30 years. After an episode of diabetic mononeuropathy or poor glycemic control, they started human insulin therapy. All the patients' serum or urinary C-peptide levels were preserved before insulin therapy, whereas within a few months they rapidly declined to below detection limits. A high titer of insulin antibody was detected at or after the development of insulin deficiency. Shortly after the initiation of insulin therapy, two of the patients developed an insulin allergy. Autoantibodies to GAD65 or IA-2 were negative throughout the clinical course in two cases, but transiently positive in one case. In a histological examination of pancreas tissue obtained by a pancreatic biopsy in one case, mononuclear cell infiltration into the islets was observed. They all had a type 1 diabetes high-risk HLA class II haplotype in Japanese, and class I alleles of the insulin gene VNTR. The above findings suggest that insulin administration may have triggered pancreatic beta-cell destruction in these patients.

Interventions for latent autoimmune diabetes (LADA) in adults

BACKGROUND

Latent autoimmune diabetes in Adults (LADA) is a slowly developing type 1 diabetes which presents as non-insulin dependent diabetes and progresses to insulin dependence. However, the best treatment strategy for LADA is unclear.

OBJECTIVES

To compare interventions used for LADA.

SEARCH STRATEGY

Studies were obtained from searches of electronic databases (including MEDLINE, EMBASE), supplemented by hand searches, conference proceedings and consultation with experts.

SELECTION CRITERIA

Selection was in duplicate by two independent reviewers. RCT and controlled clinical trials evaluating interventions for LADA or type 2 diabetes with antibodies were included.

DATA COLLECTION AND ANALYSIS

Two reviewers independently extracted data and assessed study quality. Studies were summarised in a descriptive manner.

MAIN RESULTS

Searches identified 8067 citations. Eight publications (seven studies) were included, involving 735 participants. All studies had high risk of bias. There were no data on use of metformin or glitazones alone. Rosiglitazone or sulphonylurea (SU) with insulin did not improve metabolic control significantly more than insulin alone. SU alone gave either poorer (one study, mean difference in HbA1c 2.8% (95% confidence interval (CI) 0.9 to 4.7) or equivalent metabolic control compared to insulin alone (two studies). There was evidence that SU caused earlier insulin dependence (insulin treated at two years: 60% (SU) and 5% (conventional care) (P < 0.001); classified insulin dependent: 64% (SU) and 12.5% (insulin group) (P = 0.007)). No interventions influenced fasting C-peptide, but insulin maintained stimulated C-peptide better than SU (one study, mean difference 7.7 ng/ml (95% CI 2.9 to 12.5) and insulin with rosiglitazone was superior to insulin alone (one study) at maintaining stimulated C-peptide. A pilot study showed better metabolic control at six months with subcutaneously administered glutamic acid decarboxylase (GAD) GAD65, a major autoantigen in autoimmune diabetes, compared to placebo. There was no information regarding quality of life, mortality, complications or costs in any of the publications. Time from diagnosis varied between recruitment at diagnosis to recruitment at nine years of disease duration and there was a great deal of variation in the selection criteria for LADA patients, making it difficult to generalise findings from these studies.

AUTHORS' CONCLUSIONS

There are few studies on this topic and existing studies have a high risk of bias. However, there does seem to be an indication that SU should not be a first line treatment for antibody positive type 2 diabetes. There is no significant evidence for or against other lines of treatment of LADA.

Why diabetes incidence increases--a unifying theory

There is a wide spectrum within the diabetes syndrome. Type 1 diabetes may have a slow progression with good residual insulin secretion and without autoantibodies, while phenotypic type 2 diabetes may have autoantibodies. A single patient may have traits of both types of diabetes. Their incidence increases in parallel. The etiology is mainly unknown, but environmental factors play an important role in genetically predisposed individuals. The search for just one single cause of manifest diabetes may be confusing. Different mechanism may be important in different parts of the world. Furthermore, certain mechanisms may lead to islet inflammation while other/additional mechanisms may increase insulin demand and cause insulin deficiency with manifestation of clinical diabetes. Several hypothesis of etiology may fit different parts of the disease process. Thus, increased hygiene may contribute to an imbalance of the immune system, facilitating autoimmune reactions when virus infections, or proteins like cow's milk or gluten, provoke. Increased insulin demand because of rapid growth, or insulin resistance caused by stress, infections, puberty, etc., lead to beta cell stress, antigen presentation and may cause both an autoimmune reaction in genetically predisposed individuals, and insulin deficiency leading to manifest diabetes in individuals who have lost beta cell function. Vitamins may modulate the immune process, but we know too little to give vitamin substitution. However, we do know that low physical exercise, obesity, and stress, increases insulin demand resulting in insulin deficiency. Now we can therefore intervene to prevent the diabetic syndrome.

Actual usage and clinical effectiveness of insulin preparations in patients with Type 1 diabetes mellitus in Japan: CoDiC-based analysis of clinical data obtained at multiple institutions (JDDM 3)

To clarify the actual usage of insulin preparations and their effectiveness on glycaemic control in patients with Type 1 diabetes mellitus in Japan, we analyzed clinical data collected via CoDiC, an electronic system for diabetes data collection and management, at 28 institutes. Of 18,470 diabetic patients registered with CoDiC in June, 2003, 12,279 patients were being treated with insulin preparations and/or oral hypoglycemic agents, with 861 of these patients having Type 1 diabetes mellitus and 11,418 patients having Type 2 diabetes. Three analytical surveys were carried out with the Type 1 diabetes patients. Study I: Cross-sectional survey on the treatment in 2002. Six hundred and thirteen patients received intensive conventional insulin treatment (ICT). The number of patients receiving rapid-acting insulin analogue (RA) was greater than that of patients receiving regular insulin (R). Serum CPR was lower in the patients with ICT than in the patients with conventional insulin treatment (CT). Study II: Survey on the changes in the actual usage and clinical effectiveness of insulin preparations, based on the data input in 2001 and 2002. The number of patients with ICT using RA insulin markedly increased. Study III: Analysis of the participants' clinical course over the 18-month period of the study from the time of first consultation. The dose of insulin increased during the term. The average HbA1c level fell drastically and reached to 7.5% over the first 9 months of the study and then remained between a range of 7.5% and 8% for the rest of the study period. In conclusion, ICT is actively performed and the RA insulin analogues are widely used in Type 1 diabetic patients in Japan. Basal-bolus therapy should be used to treat Type 1 diabetic patients with postprandial serum CPR of less than 0.5 ng/ml. It is difficult to obtain the ideal glycaemic control in Type 1 diabetic patients with the currently available insulin preparations.

Six-year follow-up of pancreatic β cell function in adults with latent autoimmune diabetes

AIM: To investigate the characteristics of the progression of islet β cell function in Chinese latent autoimmune diabetes in adult (LADA) patients with glutamic acid decarboxylase antibody (GAD-Ab) positivity, and to explore the prognostic factors for β cell function.

METHODS: Forty-five LADA patients with GAD-Ab positivity screened from phenotypic type 2 diabetic (T2DM) patients and 45 T2DM patients without GAD-Ab matched as controls were followed-up every 6 mo. Sixteen patients in LADA1 and T2DM1 groups respectively have been followed-up for 6 years, while 29 patients in LADA2 and T2DM2 groups respectively for only 1.5 years. GAD-Ab was determined by radioligand assay, and C-peptides (CP) by radioimmune assay.

RESULTS: The percentage of patients whose fasting CP (FCP) decreased more than 50% compared with the baseline reached to 25.0% at 1.5^th year in LADA1 group, and FCP level decreased (395.8±71.5 vs 572.8±72.3 pmol/L, P<0.05) at 2.5^th year and continuously went down to the end of follow-up. No significant changes of the above parameters were found in T2DM1 group. The average decreased percentages of FCP per year in LADA and T2DM patients were 15.8% (4.0-91.0%) and 5.2% (-3.5 to 35.5%, P = 0.000) respectively. The index of GAD-Ab was negatively correlated with the FCP in LADA patients (r_s = -0.483, P = 0.000). The decreased percentage of FCP per year in LADA patients were correlated with GAD-Ab index, body mass index (BMI) and age at onset (r_s = 0.408, -0.301 and -0.523 respectively, P<0.05). Moreover, GAD-Ab was the only risk factor for predicting β cell failure in LADA patients (B = 1.455, EXP (B) = 4.283, P = 0.023).

CONCLUSION: The decreasing rate of islet β cell function in LADA, being highly heterogeneous, is three times that of T2DM patients. The titer of GAD-Ab is an important predictor for the progression of islet β cell function, and age at onset and BMI could also act as the predictors.

Rosiglitazone combined with insulin preserves islet beta cell function in adult-onset latent autoimmune diabetes (LADA)

BACKGROUND

LADA is thought to result from the chronic autoimmune destruction of the insulin-producing pancreatic beta cells. In addition to antidiabetic effects, the newly developed insulin sensitizer-thiazolidinediones have the potential to increase the insulin content of islet cells by downregulating local inflammation and autoimmune response. Therefore, we hypothesized that LADA patients might benefit from thiazolidinediones treatment.

METHODS

LADA patients, with a fasting C-peptide (FCP) of 0.3 nmol/L or more, were enrolled and randomly assigned to receive subcutaneous insulin alone (insulin group, n = 12) or rosiglitazone plus insulin (insulin + RSG group, n = 11) to compare the impacts on islet beta cell function. Plasma glucose, HbA 1c, fasting C-peptide (FCP) and C-peptide after 2 h 75-g glucose load (PCP) were determined every 6 months. GAD-Ab and C-peptide were measured with radioimmune assays. Islet beta cell function was evaluated by PCP and DeltaCP(DeltaCP = PCP-FCP).

RESULTS

All of the 23 patients have been followed up for 6 months, 17 cases for 12 months and 14 for 18 months. (1) During 6 months' follow-up, there were no significant changes for DeltaCP and PCP levels in both groups. (2) PCP and DeltaCP levels in insulin + RSG group patients stayed steady during the 12 months' observation (P = 0.161 for both PCP and DeltaCP), while in the insulin alone group, both FCP (P = 0.021) and PCP (P = 0.028) levels decreased significantly. Furthermore, PCP (P = 0.004) and DeltaCP(P = 0.015) differences between 12th month and baseline were higher in insulin + RSG group than those in the insulin group. (3) When observed up to 18 months, PCP and DeltaCP levels in insulin + RSG group patients still stayed steady, while PCP and DeltaCP levels decreased more in the insulin alone group.

CONCLUSIONS

This pilot study suggests that rosiglitazone combined with insulin may preserve islet beta cell function in LADA patients.

Clinical and genetic characteristics of GAD-antibody positive patients initially diagnosed as having type 2 diabetes

The present study was conducted to clarify the clinical and genetic characteristics of the diabetic patients who have antibodies to glutamic acid decarboxylase (GADab) but are diagnosed initially as type 2 diabetes because of the slow progression. Fifty-five GADab+ patients and 137 GADab- patients were recruited. The GADab+ patients were divided into two subgroups according to their antibody titers. The high-titer subgroup (Ab > or = 20 U/ml) had lower urinary C-peptide concentrations, and was assigned insulin therapy more often than the GADab- patients. In contrast to the high-titer subgroup, clinical parameters in the low-titer subgroup were similar to the GADab- diabetic patients. The urinary C-peptide levels correlated negatively with the GADab titer in the GADab+ patients. Analysis of type 1 diabetes-susceptible HLA alleles revealed high frequencies of the B54 and DRB1*0405 allele, but not the B61 and DRB1*0901 alleles, in the high-titer subgroup, whereas the frequency of the protective DRB1*1502 allele was decreased. The GADab+ patients with the B54 allele had higher GADab titers and lower urinary C-peptide excretion than patients without this allele. These data indicated that patients with a high-GADab titer share the autoimmune background characteristic of type 1 diabetes.

A case of acquired deficiency of pituitary GH, PRL and TSH, associated with type 1 diabetes mellitus

A 75-year-old male showed combined anterior pituitary hormone deficiency (CPHD). Basal and TRH-stimulated PRL levels were undetectable. Basal and GRH-stimulated GH levels were very low, and could barely be measured by means of an ultrasensitive enzyme immunoassay. In addition, basal TSH levels were under the normal limit, and TRH-stimulated TSH secretions were impaired. On the other hand, the secretions of ACTH, LH and FSH remained intact. There was no mutation of Pit-1 gene in this patient, and immunohistochemical studies using human pituitary and the patient's serum showed no positive staining. The HLA types frequently detected in lymphocytic hypophysitis were recognized, supporting the view that the CPHD in this case may be caused by lymphocytic hypophysitis, although magnetic resonance imaging of the pituitary gland showed no specific findings. Interestingly, a high titer of anti-glutamic acid decarboxylase antibody, suggested that the patient suffered from type 1 diabetes mellitus (DM). Five years ago, his thyroid function was normal and the treatment of DM with oral hypoglycemic agent was effective, indicating that the onset of both diseases at least occurred within the last half decade. We report here a rare case of SPIDDM with CPHD which might be caused by lymphocytic hypophysitis.

Diabetes autoimune em adultos: características clínicas e autoanticorpos

Avaliamos a prevalência dos anticorpos anti-insulina (IAA), anti-decarboxilase do ácido glutâmico (anti-GAD), anti-ilhota de Langerhans (ICA) e as características clínicas e metabólicas de 66 pacientes com diabetes mellitus (DM) de início na idade adulta (47,2±11,6 anos) e duração do DM de 14,3±8,4 anos. RESULTADOS: ICA foi positivo em 10 casos (10 a 640U JDF), três deles também positivos para anti-GAD (15,6 a 113,5U/ml) e um deles para IAA (naqueles sem terapia insulínica). 15,2% dos pacientes tinham um ou mais autoanticorpos, com maior prevalência para ICA. Os pacientes com e sem autoanticorpos não diferiram quanto à apresentação clínica do DM ou à prevalência de complicações. Apenas os níveis de colesterol foram menores no grupo anticorpo positivo (205,2±49,6 vs. 247,1±61,3mg/dl; p<0,05). CONCLUSÃO: 15,2% dos pacientes com DM de início na idade adulta tinham um ou mais autoanticorpos, com maior prevalência para ICA. A determinação de autoanticorpos é necessária para o diagnóstico do DM autoimune.

Association of the CTLA-4 gene 49 A/G polymorphism with type 1 diabetes and autoimmune thyroid disease in Japanese children

OBJECTIVE

To clarify the role of the T-lymphocyte-associated-4 (CTLA-4) polymorphism in the susceptibility to child-onset type 1 diabetes with regard to its clinical characteristics and complications with autoimmune thyroid disease (AITD) in the Japanese population.

RESEARCH DESIGN AND METHODS

The CTLA-4 49 A/G polymorphism was detected by the PCR-restriction fragment-length polymorphism (RFLP) method in 97 type 1 diabetic subjects and 20 patients with Graves' disease, a cohort which included 4 patients who also had type 1 diabetes.

RESULTS

The genotypes and allele frequencies of this polymorphism did not differ between the type 1 diabetic subjects and the control subjects. The G allele frequency was 63.9% in the type 1 diabetic subjects. The G allele frequency in the subgroup of patients with a high titer of autoantibodies to the GAD antibody (Ab) was 72.9% (P = 0.0499 vs. control subjects); in the subgroup of patients without HLA DRB1*0405, it was 72.6% (P = 0.0271 vs. control subjects); and in the subgroup of patients with a residual beta-cell function, it was 78.6% (P = 0.0391 vs. control subjects). The G allele frequency in the patients with Graves' disease was also significantly higher at 78.1% (P = 0.0405 vs. control subjects). Furthermore, the frequency in our diabetic subjects complicated with Graves' disease was even higher (87.5%).

CONCLUSIONS

We have demonstrated that a distinct association exists between the G allele of CTLA-4 and high values of GAD Ab, residual beta-cell function, and the absence of HLA-DRB1*0405.