Saxagliptin improves glycaemic control and C-peptide secretion in latent autoimmune diabetes in adults (LADA)

Saxagliptin/dapagliflozin is non-inferior to insulin glargine in terms of β-cell function in subjects with latent autoimmune diabetes in adults: A 12-month, randomized, comparator-controlled pilot study

AIM

To compare the efficacy and safety of saxagliptin/dapagliflozin and insulin glargine in people with latent autoimmune diabetes in adults (LADA).

METHODS

In this phase 2b multicentre, open-label, comparator-controlled, parallel-group, non-inferiority study, we randomly assigned 33 people with LADA who had a fasting C-peptide concentration ≥0.2 nmol/L (0.6 ng/mL) to receive 1-year daily treatment with either the combination of saxagliptin (5 mg) plus dapagliflozin (10 mg) or insulin glargine (starting dose: 10 IU), both on top of metformin. The primary outcome was the 2-h mixed meal-stimulated C-peptide area under the curve (AUC), measured 12 months after randomization. Secondary outcomes were glycated haemoglobin (HbA1c) levels, change in body mass index (BMI), and hypoglycaemic events.

RESULTS

In the modified intention-to-treat analysis, the primary outcome was similar in participants assigned to saxagliptin/dapagliflozin or to insulin glargine (median C-peptide AUC: 152.0 ng*min/mL [95% confidence interval {CI} 68.2; 357.4] vs. 122.2 ng*min/mL [95% CI 84.3; 255.8]; p for noninferiority = 0.0087). Participants randomized to saxagliptin/dapagliflozin lost more weight than those randomized to insulin glargine (median BMI change at the end of the study: -0.4 kg/m2 [95% CI -1.6; -0.3] vs. +0.4 kg/m2 [95% CI -0.3; +1.1]; p = 0.0076). No differences in HbA1c or in the number of participants experiencing hypoglycaemic events were found.

CONCLUSIONS

Saxagliptin/dapagliflozin was non-inferior to glargine in terms of β-cell function in this 12-month, small, phase 2b study, enrolling people with LADA with still viable endogenous insulin production. Weight loss was greater with saxagliptin/dapagliflozin, with no differences in glycaemic control or hypoglycaemic risk.

Type 1 diabetes: A new vision of the disease based on endotypes

Diagnosis and management of type 1 diabetes (T1D) have remained largely unchanged for the last several years. The management of the disease remains primarily focused on its phenotypical presentation and less on endotypes, namely the specific biological mechanisms behind the development of the disease. Furthermore, the treatment of T1D is essentially universal and indiscriminate-with patients administering insulin at varying dosages and frequencies to maintain adequate glycaemic control. However, it is now well understood that T1D is a heterogeneous disease with many different biological mechanisms (i.e. endotypes) behind its complex pathophysiology. A range of factors, including age of onset, immune system regulation, rate of β-cell destruction, autoantibodies, body weight, genetics and the exposome are recognised to play a role in the development of the condition. Patients can be classified into distinct diabetic subtypes based on these factors, which can be used to categorise patients into specific endotypes. The classification of patients into endotypes allows for a greater understanding of the natural progression of the disease, giving rise to more accurate and patient-centred therapies and follow-up monitoring, specifically for other autoimmune diseases. This review proposes 6 unique endotypes of T1D based on the current literature. The recognition of these endotypes could then be used to direct therapeutic modalities based on patients' individual pathophysiology.

Efficacy of Regimens in the Treatment of Latent Autoimmune Diabetes in Adults: A Network Meta-analysis

INTRODUCTION

Latent autoimmune diabetes in adults (LADA) is a highly heterogeneous autoimmune condition with clinical and genetic characteristics that fall between those of type 1 diabetes mellitus and type 2 diabetes mellitus; therefore, there are no uniform criteria for the selection of therapeutic agents. We conducted a network meta-analysis to evaluate the efficacy of various therapeutic agents for LADA by comparing their effects on various indicators used to reflect LADA.

METHODS

We searched the PubMed, Cochrane Library, Embase and Web of Science databases from their inception to March 2023 and collected data from 14 randomized controlled trials on glucose-lowering drugs for LADA, including 23 studies and 15 treatment regimens. The effectiveness of drugs was ranked and evaluated by combining surface under the cumulative ranking (SUCRA) plots and forest plots. Factors that may influence study heterogeneity were also searched and analyzed by combining subgroup analysis, publication bias, funnel plots and sensitivity analysis.

RESULTS

The results of the network meta-analysis showed that insulin had the most significant effect on the control of change from baseline in glycosylated hemoglobin, type A1 (ΔHbA1c). Insulin combined with dipeptidyl peptidase-4 (DPP-4) inhibitors performed the best in reducing fasting blood glucose and body mass index. Treatment regimens involving thiazolidinediones were the most advantageous in HbA1c, fasting C-peptide and postprandial C-peptide control. Longer dosing may be more beneficial in maintaining islet β-cell function in the LADA population.

CONCLUSION

LADA is an immune condition with high heterogeneity, and treatment should be administered according to the C-peptide level of the LADA population. For this population with LADA with a certain level of β-cell function, combinations of insulin with DPP-4 inhibitors or thiazolidinediones probably can be more effective treatment options to maintain islet function and normal blood glucose.

TRIAL REGISTRATION

PROSPERO CRD42023410795.

Heterogeneity and endotypes in type 1 diabetes mellitus

Despite major advances over the past decade, prevention and treatment of type 1 diabetes mellitus (T1DM) remain suboptimal, with large and unexplained variations in individual responses to interventions. The current classification schema for diabetes mellitus does not capture the complexity of this disease or guide clinical management effectively. One of the approaches to achieve the goal of applying precision medicine in diabetes mellitus is to identify endotypes (that is, well-defined subtypes) of the disease each of which has a distinct aetiopathogenesis that might be amenable to specific interventions. Here, we describe epidemiological, clinical, genetic, immunological, histological and metabolic differences within T1DM that, together, suggest heterogeneity in its aetiology and pathogenesis. We then present the emerging endotypes and their impact on T1DM prediction, prevention and treatment.

Combination therapy with saxagliptin and vitamin D for the preservation of β-cell function in adult-onset type 1 diabetes: a multi-center, randomized, controlled trial

Disease modifying therapies aiming to preserve β-cell function in patients with adult-onset autoimmune type 1 diabetes are lacking. Here, we conducted a multi-centre, randomized, controlled trial to assess the β-cell preservation effects of saxagliptin alone and saxagliptin combined with vitamin D as adjunctive therapies in adult-onset autoimmune type 1 diabetes. In this 3-arm trial, 301 participants were randomly assigned to a 24-month course of the conventional therapy (metformin with or without insulin) or adjunctive saxagliptin or adjunctive saxagliptin plus vitamin D to the conventional therapy. The primary endpoint was the change from baseline to 24 months in the fasting C-peptide. The secondary endpoints included the area under the concentration-time curve (AUC) for C-peptide level in a 2-h mixed-meal tolerance test, glycemic control, total daily insulin use and safety, respectively. The primary endpoint was not achieved in saxagliptin plus vitamin D group (P = 0.18) and saxagliptin group (P = 0.26). However, compared with the conventional therapy, 2-h C-peptide AUC from 24 months to baseline decreased less with saxagliptin plus vitamin D (-276 pmol/L vs. -419 pmol/L; P = 0.01), and not to the same degree with saxagliptin alone (-314 pmol/L; P = 0.14). Notably, for participants with higher glutamic acid decarboxylase antibody (GADA) levels, the decline of β-cell function was much lower in saxagliptin plus vitamin D group than in the conventional therapy group (P = 0.001). Insulin dose was significantly reduced in both active treatment groups than in the conventional therapy group despite all groups having similar glycemic control. In conclusion, the combination of saxagliptin and vitamin D preserves pancreatic β-cell function in adult-onset autoimmune type 1 diabetes, an effect especially efficacious in individuals with higher GADA levels. Our results provide evidence for a novel adjunct to insulin and metformin as potential initial treatment for adult-onset type 1 diabetes. (ClinicalTrials.gov identifier: NCT02407899).

Adult-onset autoimmune diabetes

Adult-onset autoimmune (AOA) diabetes pathophysiology starts with immune changes, followed by dysglycaemia and overt disease. AOA diabetes can occur as classic type 1 diabetes when associated with severe loss of insulin secretion. More frequently, it is diagnosed as latent autoimmune diabetes in adults, a slowly progressing form with late onset, a long period not requiring insulin, and it is often misdiagnosed as type 2 diabetes. As its clinical presentation varies remarkably and immune markers often lack specificity, it is challenging to classify each case ad hoc, especially when insulin treatment is not required at diagnosis. Proper care of AOA diabetes aims to prevent complications and to improve quality of life and life expectancy. To achieve these goals, attention should be paid to lifestyle factors, with the aid of pharmacological therapies properly tailored to each individual clinical setting. Given the heterogeneity of the disease, choosing the right therapy for AOA diabetes is challenging. Most of the trials testing disease-modifying therapies for autoimmune diabetes are conducted in people with childhood onset, whereas non-insulin diabetes therapies have mostly been studied in the larger population with type 2 diabetes. More randomized controlled trials of therapeutic agents in AOA diabetes are needed.

Latent autoimmune diabetes in adults in China

Latent autoimmune diabetes in adults (LADA) is a type of diabetes caused by slow progression of autoimmune damage to pancreatic beta cells. According to the etiological classification, LADA should belong to the autoimmune subtype of type 1 diabetes (T1D). Previous studies have found general immune genetic effects associated with LADA, but there are also some racial differences. Multicenter studies have been conducted in different countries worldwide, but it is still unclear how the Chinese and Caucasian populations differ. The epidemiology and phenotypic characteristics of LADA may vary between Caucasian and Chinese diabetic patients as lifestyle, food habits, and body mass index differ between these two populations. The prevalence of LADA in China has reached a high level compared to other countries. The prevalence of LADA in China has reached a high level compared to other countries, and the number of patients with LADA ranks first in the world. Previous studies have found general immune genetic effects associated with LADA, but some racial differences also exist. The prevalence of LADA among newly diagnosed type 2 diabetes patients over the age of 30 years in China is 5.9%, and LADA patients account for 65% of the newly diagnosed T1D patients in the country. As a country with a large population, China has many people with LADA. A summary and analysis of these studies will enhance further understanding of LADA in China. In addition, comparing the similarities and differences between the Chinese and the Caucasian population from the perspectives of epidemiology, clinical, immunology and genetics will help to improve the understanding of LADA, and then promote LADA studies in individual populations.

Latent Autoimmune Diabetes in Adults (LADA): From Immunopathogenesis to Immunotherapy

Latent autoimmune diabetes in adults (LADA) is a type of diabetes characterized by slow autoimmune damage of pancreatic β cells without insulin treatment in the early clinical stage. There are differences between LADA and classical type 1 diabetes (T1D) and type 2 diabetes (T2D) in genetic background, autoimmune response, rate of islet function decline, clinical metabolic characteristics, and so on. The disease progression and drug response of patients with LADA are closely related to the level of islet autoimmunity, thus exploring the pathogenesis of LADA is of great significance for its prevention and treatment. Previous studies reported that adaptive immunity and innate immunity play a critical role in the etiology of LADA. Recent studies have shown that the intestinal microbiota which impacts host immunity hugely, participates in the pathogenesis of LADA. In addition, the progression of autoimmune pancreatic β cell destruction in LADA is slower than in classical T1D, providing a wider window of opportunities for intervention. Therefore, therapies including antidiabetic drugs with immune-regulation effects and immunomodulators could contribute to promising interventions for LADA. We also shed light on potential interventions targeting the gut microbiota and gut-associated immunity, which may be envisaged to halt or delay the process of autoimmunity in LADA.

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.

Innate immunity in latent autoimmune diabetes in adults

Latent autoimmune diabetes in adults (LADA) is an autoimmune disease that shares some genetic, immunological and clinical features with both type 1 diabetes and type 2 diabetes. Immune cells including CD4⁺ T cells, CD8⁺ T cells, B cells, macrophages and dendritic cells (DCs) have been detected in the pancreas of patients with LADA and a rat model of LADA. Therefore, similar to type 1 diabetes, the pathogenesis of LADA may be caused by interactions between islet β-cells and innate and adaptive immune cells. However, the role of the immunity in the initiation and progression of LADA remains largely unknown. In this review, we have summarized the potential roles of innate immunity and immune-modulators in LADA development. Furthermore, we have examined the evidence and discussed potential innate immunological reasons for the slower development of LADA compared with type 1 diabetes. More in-depth mechanistic studies are needed to fully elucidate the roles of innate immune-associated genes, molecules and cells in their contributions to LADA pathogenesis. Undertaking these studies will greatly enhance the development of new strategies and optimization of current strategies for the diagnosis and treatment of the disease.

Effects of incretin-based therapies on β-cell function in type 1 diabetes mellitus: a systematic review and meta-analysis

AIM

To assess the effects of incretin-based therapies on β-cell function in patients with type 1 diabetes mellitus (T1DM).

METHODS

We searched the PubMed, Cochrane Library, Embase, and Web of Knowledge databases for eligible randomized clinical trials published up to July 2021. The inclusion criteria were patients with T1DM or latent autoimmune diabetes in adults, patients treated with dipeptidyl peptidase-4 inhibitors or glucagon like peptide-1 receptor agonists, and outcomes included one of the following: fasting plasma glucose, fasting C-peptide, postprandial C-peptide, C-peptide area under the curve (AUC), homeostasis model assessment for β cell function, and insulin resistance. The effects were analyzed using a random effect model with STATA 11.0.

RESULTS

Eight trials including 427 participants were included in the final analysis. A pooled analysis found no significant difference in fasting plasma glucose, fasting C-peptide, postprandial C-peptide, or C-peptide AUC between patients treated with incretin-based therapies and placebo. The two trials that reported changes in 2-hour postprandial C-peptide and two of the four trials that reported changes in C-peptide AUC reported increases after incretin-based therapies.

CONCLUSION

This meta-analysis showed that incretin-based therapies did not preserve β-cell function in patients with T1DM.

Efficacy of DPP-4 inhibitors and SGLT2 inhibitors compared to sulphonylureas in adult patients with diabetes with low c-peptide levels with or without anti-GAD65 antibody positivity

BACKGROUND AND AIMS

Latent Autoimmune Diabetes of Adulthood (LADA) is different from type 2 diabetes. Present treatment protocols do not reflect that. DPP-4 and SGLT2 inhibitors have changed therapy. DPP-4 inhibitor use has shown delayed decline in beta-cell reserve in LADA. We studied patients with low c-peptide to assess relationship between c-peptide and anti-GAD65 antibody levels and compare DPP-4 inhibitors with SGLT2 inhibitors and sulphonylureas.

METHODS

The study was an open-label trial conducted in 156 participants with low c-peptide (<0.8 ng/mL), age > 25 years, recently diagnosed diabetes with HBA1c ≥ 6.5%. Participants were enrolled into three arms: Group A received sulphonylureas + metformin, Group B received DPP-4 inhibitors + metformin, and Group C received SGLT-2 inhibitors + metformin. Serum anti-GAD-65 antibodies were assessed using sandwich ELISA. Participants were assessed on enrolment and after three months of dual pharmacotherapy.

RESULTS

The three arms were comparable on enrolment. 52% of participants with low c-peptide had high anti-GAD65 antibody titers. Significant differences were observed after three months - DPP-4 inhibitors reduced HbA1c by 1.1 ± 0.3%, compared to SGLT2 inhibitors (0.8 ± 0.13%) and sulphonylureas (0.7 ± 0.3%) CONCLUSION: DPP-4 inhibitors appear to provide better glycemic control than alternate therapeutic options in patients with low serum c-peptide.

The role of incretins and incretin-based drugs in autoimmune diseases

Incretin hormones, including glucagon-like peptide (GLP)-1, GLP-2 and glucose-dependent insulinotropic polypeptide (GIP), are gastrointestinal peptides secreted from enteroendocrine cells. These hormones play significant roles in many physiological processes via binding to G-protein coupled receptors (GPCRs) on different organs and tissues; one of them is the immunomodulatory effect on the immune system and its molecular components such as cytokines and chemokines. Anti-inflammatory effects of incretins and dependent molecules involving long-acting analogs and DPP4 inhibitors through regulation of T and B cell activation may attenuate autoimmune diseases caused by immune system disorders in mistakenly recognizing self as the foreign agent. In this review, we investigate incretin effects on the immune system response and the potential benefits of incretin-based therapy for treating autoimmune diseases.

Covalent Small Molecule Immunomodulators Targeting the Protease Active Site

Cells of the immune system utilize multiple proteases to regulate cell functions and orchestrate innate and adaptive immune responses. Dysregulated protease activities are implicated in many immune-related disorders; thus, protease inhibitors have been actively investigated for pharmaceutical development. Although historically considered challenging with concerns about toxicity, compounds that covalently modify the protease active site represent an important class of agents, emerging not only as chemical probes but also as approved drugs. Here, we provide an overview of technologies useful for the study of proteases with the focus on recent advances in chemoproteomic methods and screening platforms. By highlighting covalent inhibitors that have been designed to target immunomodulatory proteases, we identify opportunities for the development of small molecule immunomodulators.

Islet Function and Insulin Sensitivity in Latent Autoimmune Diabetes in Adults Taking Sitagliptin: A Randomized Trial

CONTEXT

The long-term effects of dipeptidyl peptidase-4 inhibitors on β-cell function and insulin sensitivity in latent autoimmune diabetes in adults (LADA) are unclear.

OBJECTIVE

To investigate the effects of sitagliptin on β-cell function and insulin sensitivity in LADA patients receiving insulin.

DESIGN AND SETTING

A randomized controlled trial at the Second Xiangya Hospital.

METHODS

Fifty-one patients with LADA were randomized to sitagliptin + insulin (SITA) group or insulin alone (CONT) group for 24 months.

MAIN OUTCOME MEASURES

Fasting C-peptide (FCP), 2-hour postprandial C-peptide (2hCP) during mixed-meal tolerance test, △CP (2hCP - FCP), and updated homeostatic model assessment of β-cell function (HOMA2-B) were determined every 6 months. In 12 subjects, hyperglycemic clamp and hyperinsulinemic euglycemic clamp (HEC) tests were further conducted at 12-month intervals.

RESULTS

During the 24-month follow-up, there were no significant changes in β-cell function in the SITA group, whereas the levels of 2hCP and △CP in the CONT group were reduced at 24 months. Meanwhile, the changes in HOMA2-B from baseline were larger in the SITA group than in the CONT group. At 24 months, first-phase insulin secretion was improved in the SITA group by hyperglycemia clamp, which was higher than in the CONT group (P < .001), while glucose metabolized (M), insulin sensitivity index, and M over logarithmical insulin ratio in HEC were increased in the SITA group (all P < .01 vs baseline), which were higher than in the CONT group.

CONCLUSION

Compared with insulin intervention alone, sitagliptin plus insulin treatment appeared to maintain β-cell function and improve insulin sensitivity in LADA to some extent.

Combination of vitamin D and dipeptidyl peptidase-4 inhibitors (VIDPP-4i) as an immunomodulation therapy for autoimmune diabetes

Type 1 diabetes (T1D) and latent autoimmune diabetes in adults (LADA) represent the most common types of autoimmune diabetes and are characterized by different age of onset, degrees of immune-mediated destruction of pancreatic beta cells and rates of disease progression towards insulin dependence. Several immunotherapies aimed to counteract autoimmune responses against beta cells and preserve beta-cell function are currently being investigated, particularly in T1D. Preliminary findings suggest a potential role of combination therapy with vitamin D and dipeptidyl peptidase-4 (DPP-4) inhibitors (VIDPP-4i) in preserving beta-cell function in autoimmune diabetes. This manuscript aims to provide a comprehensive overview of the immunomodulatory properties of vitamin D and DPP-4 inhibitors, as well as the rationale for investigation of their combined use as an immunomodulation therapy for autoimmune diabetes.

Management of Latent Autoimmune Diabetes in Adults: A Consensus Statement From an International Expert Panel

A substantial proportion of patients with adult-onset diabetes share features of both type 1 diabetes (T1D) and type 2 diabetes (T2D). These individuals, at diagnosis, clinically resemble T2D patients by not requiring insulin treatment, yet they have immunogenetic markers associated with T1D. Such a slowly evolving form of autoimmune diabetes, described as latent autoimmune diabetes of adults (LADA), accounts for 2-12% of all patients with adult-onset diabetes, though they show considerable variability according to their demographics and mode of ascertainment. While therapeutic strategies aim for metabolic control and preservation of residual insulin secretory capacity, endotype heterogeneity within LADA implies a personalized approach to treatment. Faced with a paucity of large-scale clinical trials in LADA, an expert panel reviewed data and delineated one therapeutic approach. Building on the 2020 American Diabetes Association (ADA)/European Association for the Study of Diabetes (EASD) consensus for T2D and heterogeneity within autoimmune diabetes, we propose "deviations" for LADA from those guidelines. Within LADA, C-peptide values, proxy for β-cell function, drive therapeutic decisions. Three broad categories of random C-peptide levels were introduced by the panel: 1) C-peptide levels <0.3 nmol/L: a multiple-insulin regimen recommended as for T1D; 2) C-peptide values ≥0.3 and ≤0.7 nmol/L: defined by the panel as a "gray area" in which a modified ADA/EASD algorithm for T2D is recommended; consider insulin in combination with other therapies to modulate β-cell failure and limit diabetic complications; 3) C-peptide values >0.7 nmol/L: suggests a modified ADA/EASD algorithm as for T2D but allowing for the potentially progressive nature of LADA by monitoring C-peptide to adjust treatment. The panel concluded by advising general screening for LADA in newly diagnosed non-insulin-requiring diabetes and, importantly, that large randomized clinical trials are warranted.

Adding vitamin D3 to the dipeptidyl peptidase-4 inhibitor saxagliptin has the potential to protect β-cell function in LADA patients: A 1-year pilot study

AIMS

This trial was conducted to explore the protective effect on β-cell function of adding vitamin D3 to DPP-4 inhibitors to treat patients with latent autoimmune diabetes in adults (LADA).

METHODS

60 LADA patients were randomized to group A (n = 21) - conventional therapy with metformin (1-1.7 g/day) and/or insulin treatment; group B (n = 20) - saxagliptin (5 mg/day) plus conventional therapy; and group C (n = 19) - vitamin D3 (2000 IU/day) plus saxagliptin and conventional therapy for 12 months. Fasting and 2-hour postprandial blood samples were collected to measure blood glucose, glycosylated hemoglobin and C-peptide levels at baseline and after 3, 6 and 12 months of treatment.

RESULTS

During the 12 months of follow-up, the levels of fasting C-peptide (FCP), 2-hour postprandial C-peptide (PCP) and the C-peptide index (CPI, serum C-peptide-to-plasma glucose level ratio) were maintained in group C. In contrast to those in group A and group B, FCP levels decreased significantly in group B, and CPI levels declined significantly in group A during the 1-year treatment (P < .05). Additionally, the levels of GADA titers in group C significantly decreased compared with those at baseline (P < .05), but no significant differences in GADA titers levels were detected in group A and group B. No significant differences were found among the three groups in the levels of FCP, PCP, the CPI or GADA titers.

CONCLUSIONS

The data suggested that adding 2000 IU/day vitamin D3 to saxagliptin might preserve β-cell function in patients with LADA.

Therapeutic approaches for latent autoimmune diabetes in adults: One size does not fit all

Recent advances in the understanding of latent autoimmune diabetes in adults (LADA) pathophysiology make it increasingly evident that people with LADA comprise a heterogenous group of patients. This makes the establishment of a standard treatment algorithm challenging. On top of its glucose-lowering action, insulin may exert anti-inflammatory effects, rendering it an attractive therapeutic choice for a type of diabetes in which autoinflammation and beta cell insufficiency play major pathogenetic roles. However, there is growing evidence that other antidiabetic drugs, such as metformin, dipeptidyl peptidase-4 inhibitors, glucagon-like peptide-1 receptor agonists, and thiazolidinediones, might have a role in optimizing glycemic control and preserving beta cell function in individuals with LADA, either alone or in combination with insulin. Although most of these drugs have been routinely used in the daily clinical setting for years, large prospective randomized trials are needed to assess whether they are capable of delaying progression to insulin dependence as well as their effects on diabetic complications. The aim of the present review is to discuss the current state and future perspectives of LADA therapy, emphasizing the need for individualized and patient-centered therapeutic approaches.

Latent Autoimmune Diabetes in Adults: A Review of Clinically Relevant Issues

Latent autoimmune diabetes in adults (LADA) is still a poorly characterized entity. However, its prevalence may be higher than that of classical type 1 diabetes. Patients with LADA are often misclassified as type 2 diabetes. The underlying autoimmune process against β-cell has important consequences for the prognosis, comorbidities, treatment choices and even patient-reported outcomes with this diabetes subtype. However, there is still an important gap of knowledge in many areas of clinical relevance. We are herein focusing on the state of knowledge of relevant clinical issues than may help in the diagnosis and management of subjects with LADA.

Past, present and future of latent autoimmune diabetes in adults

Latent autoimmune diabetes in adults (LADA) is the most common form of autoimmune diabetes diagnosed in adults. Similar to type 1 diabetes, the prevalence of LADA is impacted by ethnicity and geography. LADA is characterized by β cell loss due to autoimmunity and insulin resistance and has highly heterogeneous clinical features, autoimmunity, and genetics in a glutamic acid decarboxylase antibody (GADA) titre-dependent manner, suggesting LADA is part of a continuum spectrum between type 1 and type 2 diabetes. Although LADA is the most frequent form of autoimmune diabetes diagnosed in adults, clinical trials involving LADA are scarce. Here we review the recent advancements in LADA epidemiology, clinical features, pathogenesis, and interventions. We also highlight the environmental factors that are thought to play an important role in addition to genetics in the pathogenesis of LADA. In the future, high-throughput molecular profiles might shed light on the nature of LADA among the wide spectrum of diabetes and offer new opportunities to identify novel LADA-specific biomarkers.

Investigating optimal β-cell-preserving treatment in latent autoimmune diabetes in adults: Results from a 21-month randomized trial

AIMS

To compare outcomes of glucagon-stimulated C-peptide tests (GSCTs) in people with latent autoimmune diabetes in adults (LADA) after a 21-month intervention with either insulin or the dipeptidyl peptidase-4 inhibitor sitagliptin.

RESEARCH DESIGN AND METHODS

We included 64 glutamic acid decarboxylase (GAD) antibody-positive individuals, who were diagnosed with diabetes <3 years before the study, aged 30 to 70 years, and without clinical need for insulin treatment. We stratified participants by age and body mass index (BMI) and evaluated β-cell function by GSCT after a 48-hour temporary withdrawal of study medication.

RESULTS

Age at randomization (mean 53 years), BMI (mean 27 kg/m² ) and metabolic markers were similar between treatment arms. Glycated haemoglobin concentrations during intervention did not differ between arms. Fasting C-peptide concentrations after the intervention were similar, as were stimulated C-peptide levels (0.82 ± 0.63 nmol/L after insulin, 0.82 ± 0.46 nmol/L after sitagliptin; nonsignificant). Autoimmunity in the study population (estimated from GAD antibody titres and positivity/no positivity for zinc transporter 8 and islet antigen 2 antibodies) affected the evolution of the GSCT results significantly, which deteriorated in participants with high but not in those with low autoimmunity. Adjustment using analysis of covariance for the degree of autoimmunity did not alter the findings of no difference between treatment arms.

CONCLUSIONS

β-cell function after intervention was similar in patients with insulin- and sitagliptin-treated LADA, regardless of the strength of autoimmunity. Further, participants with low levels of GAD antibodies did not experience progressive deterioration of β-cell function over a 21-month period. Taken together, these findings could be useful for clinicians' choices of treatment in people with LADA.

Ten years of experience with DPP-4 inhibitors for the treatment of type 2 diabetes mellitus

Achieving and maintaining recommended glycemic targets without causing adverse e ffects, including hypoglycemia, is challenging, especially in older patients with type 2 diabetes mellitus (T2DM). The introduction of dipeptidyl peptidase-4 (DPP-4) inhibitors, more than 10 years ago, has provided an alternative to conventional medications for the intensification of glucose-lowering treatment after failure of metformin monotherapy, and therefore, marked an important advance in the management of T2DM. By prolonging the activity of incretin hormones, DPP-4 inhibitors induce insulin release and decrease glucagon secretion in a glucose-dependent manner. This results in a more physiologic glycemic control as compared to that ensured by insulin secretagogues (sulfonylureas and glinides). Overall, DPP-4 inhibitors have a favorable safety profile and can be used without dose adjustments in older adults and in patients with mild renal impairment; they have a neutral effect on body weight and do not cause hypoglycemia by themselves. Safety issues, reported mainly in post-marketing surveillance programs and including cardiovascular outcomes and the risk of acute pancreatitis, are being extensively investigated. The aim of this review is to discuss the impact of DPP-4 inhibitors on the treatment of T2DM, after 10 years of experience, with an emphasis on diabetes care in Italy. We will first describe T2DM treatment in Italy and then provide an overview of the main findings from randomized controlled trials, real-world studies and post-marketing surveillance programs with DPP-4 inhibitors.

Using DPP-4 inhibitors to modulate beta cell function in type 1 diabetes and in the treatment of diabetic kidney disease

INTRODUCTION

DPP-4 inhibitors have pleomorphic effects that extend beyond the anti-hyperglycemic labeled use of the drug. DPP-4 inhibitors have demonstrated promising renal protective effects in T2DM and T1DM and protective effects against immune destruction of pancreatic beta-cells in T1DM.

AREAS COVERED

The efficacy of DPP-4 inhibitors in the treatment of diabetic kidney disease and possible adjunct with insulin in the treatment of T1DM to preserve beta-cell function. Pertinent literature was identified through Medline, PubMed and ClinicalTrials.gov (1997-November 2018) using the search terms T1DM, sitagliptin, vildagliptin, linagliptin, beta-cell function, diabetic nephropathy. Only articles are written in the English language, and clinical trials evaluating human subjects were used.

EXPERT OPINION

DPP-4 inhibitors can be used safely in patients with diabetic kidney disease and do not appear to exacerbate existing diabetic nephropathy. Linagliptin reduces albuminuria and protects renal endothelium from the deleterious effects of hyperglycemia. The effects of DPP-4 inhibitors on preserving beta-cell function in certain subtypes of T1DM [e.g. Latent Autoimmune Diabetes in Adult (LADA) and Slowly Progressive Type 1 Diabetes (SPIDDM)] are encouraging and show promise.

Altered T-cell subsets and transcription factors in latent autoimmune diabetes in adults taking sitagliptin, a dipeptidyl peptidase-4 inhibitor: A 1-year open-label randomized controlled trial

AIMS/INTRODUCTION

Dipeptidyl peptidase-4 inhibitor has been proven to improve glycemic control and β-cell function in latent autoimmune diabetes in adults (LADA). The potential immune modulation mechanism is still unknown. Thus, we tested T-lymphocyte subsets and expression of relevant transcription factors in LADA patients with sitagliptin intervention for up to 1-year.

MATERIALS AND METHODS

A total of 40 LADA patients were randomly assigned to sitagliptin and/or insulin treatment (SITA group; n = 20) or insulin alone treatment (CONT group; n = 20). Peripheral blood mononuclear cells were isolated at baseline, 6 months and 12 months. The percentage of T-lymphocyte subsets (T helper 1, T helper 2, T helper 17 and regulatory T cells) tested by flow cytometry, and the messenger ribonucleic acid expression (T box expressed in T cells [T-BET], GATA binding protein 3 [GATA3], forkhead box protein 3 [FOXP3] and related orphan receptor C [RORC]) tested by real-time polymerase chain reaction were determined at baseline, 6 months and 12 months.

RESULTS

The percentage of regulatory T cells in the SITA group was significantly lower than that of the CONT group at baseline. The percentage of T helper 2 cells was higher than that of the CONT group at 6 months and 12 months. At 12 months, the percentage of T helper 17 cells was lower in the SITA group than that of the CONT group. After a 1-year visit, the messenger ribonucleic acid expression levels of T-BET expressed in T cells and RORC in the SITA group were significantly lower than at baseline. Whereas that of RORC in the CONT group were significantly lower than that at baseline.

CONCLUSIONS

The data confirmed that sitagliptin altered the phenotype of T cells and downregulated the expression of T-BET and RORC in LADA patients, and ameliorated glycemic control in LADA patients.

Slowly Progressive Type 1 Diabetes Mellitus: Current Knowledge And Future Perspectives

Slowly progressive type 1 insulin-dependent diabetes mellitus (SPIDDM), sometimes referred to as latent autoimmune diabetes in adults (LADA), is a heterogeneous disease that is often confused with type 1 and type 2 diabetes. As a result, there were few diagnostic criteria for this disorder until 2012, when the Japan Diabetes Society established criteria that could be used in clinical practice. A primary question is whether pathologic markers for type 1 or type 2 diabetes are present in the pancreas of patients with SPIDDM, because the phenotype of SPIDDM is similar to both type 1 and type 2 diabetes. Recent studies clarified pathologic findings in the pancreas of patients with SPIDDM, which included T-cell-mediated insulitis, a marker of type 1 diabetes; pseudoatrophic islets (islets specifically devoid of beta cells), another hallmark of type 1 diabetes; and a lack of amylin (ie, islet amyloid polypeptide) deposition to the islet cells, a pathologic marker of type 2 diabetes. In terms of preventing the loss of beta-cell function in patients with SPIDDM, several studies have shown that some drugs, including dipeptidyl peptidase-4 inhibitors, are effective. There is an increased need for early diagnosis of SPIDDM to preserve beta-cell function. This review presents updated findings on the pathogenesis and immunologic findings of the affected pancreas, diagnostic markers, risk factors for progression of beta-cell dysfunction, epidemiology, clinical features, diagnostic strategies, prevention strategies, and clinical options for patients with SPIDDM.

Urinary C-Peptide Creatinine Ratio as a Non-Invasive Tool for Identifying Latent Autoimmune Diabetes in Adults (LADA)

PURPOSE

Latent autoimmune diabetes in adults (LADA) is a slowly progressing form of immune-mediated diabetes that combines phenotypical features of both type 2 diabetes mellitus (T2DM) and type 1 diabetes mellitus (T1DM), meaning that accurate and early diagnosis of this subtype of diabetes is critical for optimal long-term management. Urinary C-peptide creatinine ratio (UCPCR) represents a non-invasive and practical method for assessing endogenous insulin production to facilitate diabetes classification. However, no study to date has reported the use of UCPCR in identifying LADA.

PATIENTS AND METHODS

A total of 574 subjects were included in our study (42 LADA, 61 T1DM, 471 T2DM). All participants were evaluated for UCPCR and underwent clinical and laboratory evaluations. UCPCR was compared among different subtypes of diabetes using multinomial regression analysis, and a receiver operating characteristic (ROC) curve was used to identify its performance in diagnosing LADA.

RESULTS

UCPCR was lower in LADA (0.4±0.6 nmol/mmol) compared with T2DM (1.2±0.9 nmol/mmol), but higher than in T1DM (0.2±0.3 nmol/mmol) (p<0.05). The association between UCPCR and LADA remained significant after adjusting for gender, age, age at diagnosis, body mass index, high-density lipoprotein cholesterol, and triglyceride (OR, 95% confidence interval (CI), 0.29 (0.09, 0.95)). The ROC curve revealed an area under the curve of 0.835 (95% CI (0.742-0.928), p<0.001). The cut-off point for UCPCR ≤ 0.46 nmol/mmol was 82.1% for sensitivity and 76.7% for specificity in the diagnosis of LADA.

CONCLUSION

UCPCR may represent a non-invasive, simple, and practical measurement of insulin secretion for early discrimination of LADA in routine clinical practice.

Treatment of Latent Autoimmune Diabetes in Adults: What is Best?

Latent Autoimmune Diabetes in Adults (LADA), although formally classified as Type 1 Diabetes (T1D), very often (at least in Western countries) appear clinically with Type 2 Diabetes (T2D)-like features as overweight and insulin resistance. LADA patients do not need exogenous insulin at the time they are diagnosed with diabetes, but a large percentage will within a few years develop need for such treatment. The decline in beta cell function progresses much faster in LADA than in T2D, presumably because of the ongoing autoimmune assault in LADA, and therefore necessitates insulin therapy much earlier in LADA than in T2D. Despite high prevalence of LADA (about 10% of the total diabetic population in many countries), the treatment of LADA patients is far less elucidated than is the case for T1D and T2D. Finding a treatment strategy for LADA from the time of diagnosis, that can reduce the decline of beta cell function, ensure adequate metabolic control and thereby reduce the risk of diabetic complications is thus an important clinical challenge. Conclusions from the randomized treatment studies so far do not indicate an optimal treatment strategy in LADA. This review aims to give an overview of current practices for the medical treatment of LADA as well as an update on results from recent studies on the treatment of the disease.

Latent Autoimmune Diabetes in Adults: A Review on Clinical Implications and Management

Latent autoimmune diabetes in adults (LADA) is a heterogeneous disease characterized by a less intensive autoimmune process and a broad clinical phenotype compared to classical type 1 diabetes mellitus (T1DM), sharing features with both type 2 diabetes mellitus (T2DM) and T1DM. Since patients affected by LADA are initially insulin independent and recognizable only by testing for islet-cell autoantibodies, it could be difficult to identify LADA in clinical setting and a high misdiagnosis rate still remains among patients with T2DM. Ideally, islet-cell autoantibodies screening should be performed in subjects with newly diagnosed T2DM, ensuring a closer monitoring of those resulted positive and avoiding treatment of hyperglycaemia which might increase the rate of β-cells loss. Thus, since the autoimmune process in LADA seems to be slower than in classical T1DM, there is a wider window for new therapeutic interventions that may slow down β-cell failure. This review summarizes the current understanding of LADA, by evaluating data from most recent studies, the actual gaps in diagnosis and management. Finally, we critically highlight and discuss novel findings and future perspectives on the therapeutic approach in LADA.

Dipeptidyl peptidase-4(DPP-4) inhibitors: promising new agents for autoimmune diabetes

Dipeptidyl peptidase-4 (DPP-4) inhibitors constitute a novel class of anti-diabetic agents confirmed to improve glycemic control and preserve β-cell function in type 2 diabetes. Three major large-scale studies, EXAMINE, SAVOR-TIMI 53, and TECOS, have confirmed the cardiovascular safety profile of DPP-4 inhibitors. Based on these results, DPP-4 inhibitors have gained widespread use in type 2 diabetes treatment. It is currently unknown, however, whether DPP-4 inhibitors have similar therapeutic efficacy against autoimmune diabetes. Several in vitro and in vivo studies have addressed this issue, but the results remain controversial. In this review, we summarize experimental findings and preliminary clinical trial results, and identify potentially effective immune modulation targets of DPP-4 inhibitors for autoimmune diabetes.

Dulaglutide treatment results in effective glycaemic control in latent autoimmune diabetes in adults (LADA): A post-hoc analysis of the AWARD-2, -4 and -5 Trials

AIMS

Patients with a type-2-diabetes (T2D) phenotype positive for glutamic acid decarboxylase antibodies (GADA) represent the majority of cases of latent autoimmune diabetes of the adult (LADA). The GLP-1 receptor agonist dulaglutide, recently introduced for treatment of T2D, has yet to be evaluated in LADA patients. Our primary objective was to evaluate the effect of dulaglutide on glycaemic control (HbA1c) in GADA-positive LADA vs GADA-negative T2D patients.

METHODS

A post-hoc analysis was performed using data from 3 randomized phase 3 trials (AWARD-2,-4,-5; patients with GADA assessment) which were part of the dulaglutide clinical development programme in T2D. LADA patients were identified by GADA ≥5 IU/mL (ELISA). Changes in HbA1c during 12 months of treatment with dulaglutide or comparator were analysed using mixed-effect model repeated measures.

RESULTS

Of 2466 adults tested for GADA (dulaglutide, 1710; glargine, 298; sitagliptin, 294; placebo, 164), 2278 (92.4%) were GADA-negative and 188 (7.6%) were GADA-positive, including 58 GADA-high patients (> 200 IU/mL) and 130 GADA-low patients (≤200 and ≥5 IU/mL). Overall, baseline parameters were comparable between the groups. Dulaglutide resulted in comparable HbA1c reductions in GADA-negative (LS mean change [95%CI], -1.09% [-1.15, -1.03]) and GADA-positive patients (-0.94% [-1.15, -0.72]) at 12 months. HbA1c reductions were numerically, but not statistically, significantly larger in GADA-low patients (-1.02% [-1.26, -0.78]) vs GADA-high patients (-0.72% [-1.21,-0.24]) at 12 months. Similar outcomes were observed at 3 and 6 months.

CONCLUSIONS

These data are the first to indicate that dulaglutide was effective in reducing HbA1c in LADA patients.

Latent Autoimmune Diabetes in Adults: Current Status and New Horizons

Autoimmune diabetes is a heterogeneous disease which can arise at any age. Subjects with adult-onset autoimmune diabetes who do not necessitate insulin-therapy for at least 6 months after diagnosis are demarcated as having latent autoimmune diabetes in adults (LADA). This condition is more heterogeneous than young-onset autoimmune diabetes and shares clinical and metabolic characteristics with both type 2 and type 1 diabetes. Patients with LADA are considered by having highly variable β-cell destruction, different degrees of insulin resistance and heterogeneous titre and pattern of islet autoantibody, suggesting different pathophysiological pathways partially explaining the heterogeneous phenotypes of LADA. To date the heterogeneity of LADA does not allow to establish a priori treatment algorithm and no specific guidelines for LADA therapy are available. These subjects are mostly treated as affected by type 2 diabetes, a factor that might lead to the progression to insulin-dependency quickly. A personalised medicine approach is necessary to attain optimal metabolic control and preserve β-cell function to decrease the risk of long-term diabetes complications. Recent data concerning the use of oral antidiabetic agents as dipeptidyl peptidase 4 inhibitors and glucagon-like peptide 1 receptor agonists indicate up-and-coming results in term of protect C-peptide levels and improving glycaemic control. This review summarises current knowledge on LADA, emphasising controversies regarding its pathophysiology and clinical features. Moreover, we discuss data available about novel therapeutic approaches that can be considered for prevention of β-cell loss in LADA.

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.

Possible Long-Term Efficacy of Sitagliptin, a Dipeptidyl Peptidase-4 Inhibitor, for Slowly Progressive Type 1 Diabetes (SPIDDM) in the Stage of Non-Insulin-Dependency: An Open-Label Randomized Controlled Pilot Trial (SPAN-S)

INTRODUCTION

We tested the hypothesis that dipeptidyl peptidase-4 (DPP-4) inhibitors are effective in preserving the β-cell function for long-term periods in patients with slowly progressive type 1 diabetes (SPIDDM) or latent autoimmune diabetes in adults (LADA).

METHODS

In the present open-label, randomized, controlled trial, 14 non-insulin-requiring diabetic patients with glutamic acid decarboxylase autoantibodies (GADAb) were randomly assigned to receive either sitagliptin (S group) or pioglitazone (P group). As a historical control, the Tokyo Study, in which non-insulin-dependent patients with SPIDDM were assigned to receive treatment by either insulin or sulfonylurea (SU), was used.

RESULTS

On average, the ∑C-peptide values during the oral glucose tolerance test through the follow-up periods showed a nonsignificant increase in the S group (n = 6, n = 5 at 48 months) compared to the P group (n = 5, n = 2 at 48 months). In comparison to the data in the Tokyo Study, treatment by sitagliptin significantly influenced the longitudinal changes in the ∑C-peptide values with a more increased direction than insulin or SU, especially in patients with 48 months of follow-up (p = 0.014 and p = 0.007, respectively). Although the titers of GADAb were not significantly different between the S and P groups during the study, the change ratio of the GADAb titers from baseline was significantly inversely correlated with the change ratio of the ∑C-peptide values from baseline in the S group (p = 0.003); in particular, when the GADAb titers decreased from baseline, the ∑C-peptide values frequently increased.

CONCLUSION

The present pilot trial suggests that treatment of SPIDDM/LADA by sitagliptin, a DPP-4 inhibitor, may be more effective in preserving the β-cell function than insulin treatment for at least 4 years, possibly through the immune modulatory effects of DPP-4 inhibitors.

CLINICAL TRIAL REGISTRATION

Japanese Clinical Trials Registry UMIN000003693.

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.

Efficacy and safety of incretin-based drugs in patients with type 1 diabetes mellitus: A systematic review and meta-analysis

AIMS

In patients with type 2 diabetes, incretin-based therapies can improve glucose control without increased weight gain or hypoglycemia. Incretin-based drugs added to insulin therapy in type 1 diabetes (T1DM) have also been tried in many studies. However, the results were controversial. We thus performed a meta-analysis to assess the efficacy and safety of incretin-based therapies in patients with T1DM.

METHODS

We systematically searched Medline, EMBASE, and Cochrane Central Register of Controlled Trials for relevant studies published before August 25, 2016. Data was extracted by two independent reviewers. The main outcomes included glycosylated hemoglobin (HbA1c), insulin dose, weight, hypoglycemia, ketosis and ketoacidosis. All pooled data were assessed using random-effects model.

RESULTS

Twelve randomized controlled trials with a total of 2903 individuals were finally included into the meta-analysis. Incretin-based drugs could significantly reduce HbA1c (MD -0.20, 95% CI -0.30 to -0.10), weight (MD -2.83, 95% CI -4.00 to -1.65) and insulin dose (MD -4.55, 95% CI -6.15 to -2.94). Furthermore, incretin-based drugs did not increase relative risk of severe hypoglycemia (RR 0.79, 95% CI 0.58 to 1.06), ketosis (RR 1.37, 95% CI 0.95 to 1.97) and ketoacidosis (RR 2.62, 95% CI 0.31 to 21.99).

CONCLUSIONS

Incretin-based treatment in patients with T1DM may improve glycemic control and reduce insulin dose and weight without increasing the risk of serious adverse event, such as severe hypoglycemia, ketosis or ketoacidosis. The current evidence for the aforementioned adverse effects, however, is weak. A rigorous monitoring of these adverse events should be implemented in well-designed observational studies.

Should There be Concern About Autoimmune Diabetes in Adults? Current Evidence and Controversies

Autoimmune diabetes has a heterogeneous phenotype. Although often considered a condition starting in childhood, a substantial proportion of type 1 diabetes presents in adult life. This holds important implications for our understanding of the factors that modify the rate of progression through the disease prodrome to clinical diabetes and for our management of the disease. When autoimmune diabetes develops in adulthood, insulin treatment is often not required at the time of diagnosis, and this autoimmune non-insulin requiring diabetes is generally termed latent autoimmune diabetes in adults (LADA). Patients with LADA are generally leaner, younger at diabetes onset; have a greater reduction in C-peptide; and have a greater likelihood of insulin treatment as compared with patients with type 2 diabetes. The LADA subset of patients with adult-onset autoimmune diabetes has highlighted many shortcomings in the classification of diabetes and invokes the case for more personalized data analysis in line with the move towards precision medicine. Perhaps most importantly, the issues highlight our persistent failure to engage with the heterogeneity within the most common form of autoimmune diabetes, that is adult-onset type 1 diabetes, both insulin-dependent and initially non-insulin requiring (LADA). This review discusses characteristics of autoimmune diabetes and specifically aims to illustrate the heterogeneity of the disease.

Combined treatment with sitagliptin and vitamin D in a patient with latent autoimmune diabetes in adults

Latent autoimmune diabetes in adults (LADA) is a relatively new type of diabetes with a clinical phenotype of type 2 diabetes (T2D) and an immunological milieu characterized by high titers of islet autoantibodies, resembling the immunological profile of type 1 diabetes (T1D). Herein, we report a case of a young male, diagnosed with LADA based on both clinical presentation and positive anti-glutamic acid decarboxylase antibodies (GAD-abs), which were normalized after combined treatment with a dipeptidyl peptidase-4 inhibitor (DPP-4) (sitagliptin) and cholecalciferol.

An Update on the Effect of Incretin-Based Therapies on β-Cell Function and Mass

Type 2 diabetes mellitus (T2DM) is a multifactorial disease with a complex and progressive pathogenesis. The two primary mechanisms of T2DM pathogenesis are pancreatic β-cell dysfunction and insulin resistance. Pancreatic β-cell dysfunction is recognized to be a prerequisite for the development of T2DM. Therapeutic modalities that improve β-cell function are considered critical to T2DM management; however, blood glucose control remains a challenge for many patients due to suboptimal treatment efficacy and the progressive nature of T2DM. Incretin-based therapies are now the most frequently prescribed antidiabetic drugs in Korea. Incretin-based therapies are a favorable class of drugs due to their ability to reduce blood glucose by targeting the incretin hormone system and, most notably, their potential to improve pancreatic β-cell function. This review outlines the current understanding of the incretin hormone system in T2DM and summarizes recent updates on the effect of incretin-based therapies on β-cell function and β-cell mass in animals and humans.