Low-risk HLA genotype in Type 1 diabetes is associated with less destruction of pancreatic B-cells 12 months after diagnosis

Annual decline in β-cell function in patients with type 2 diabetes in China

BACKGROUND

The aim of this study was to investigate the annual decline of β-cell function correlated with disease duration in patients with type 2 diabetes in China.

METHODS

This cross-sectional study included 4792 adults with type 2 diabetes who were recruited from four university hospital diabetes clinics between April 2018 and November 2018. Baseline data were collected from electric medical records. Participants were divided into 21 groups with 1-year diabetes duration interval to assess the decline rate of β-cell function. Homeostatic model assessment model (HOMA 2) model was applied to assess β-cell function. Multiple linear regression model was used to evaluate the association between biochemical and clinical variables and β-cell function.

RESULTS

In Chinese patients with type 2 diabetes, β-cell function declined by 2% annually. Using angiotensin receptor blockade (ARB) (β = .048; P = .011), metformin (β = .138; P = .021), or insulin (β = .142; P = .018) was associated with increased β-cell function. However, increased BMI (β = -.215; P = .022), alcohol consumption (β = -.331; P < .001), haemoglobin A1c (β = -.104; P = .027), or increased diabetes duration (β = -.183; P = .003) was significantly and negatively associated with β-cell function.

CONCLUSIONS

We determined that the annual rate of the β-cell function decline was 2% in patients with type 2 diabetes in China. Moreover, we confirmed a positive relationship between ARB treatment and β-cell function, while BMI and alcohol consumption were significantly and negatively associated with the β-cell function.

Prognosis for residual islet β-cell secretion function in young patients with newly diagnosed type 1 diabetes

BACKGROUND

This study investigated possible predictors of residual islet β-cell function (RBF) in young patients with newly diagnosed type 1 diabetes (T1D).

METHODS

After analyzing RBF in 443 patients with T1D according to age at diagnosis and disease duration, 110 were followed-up over 18-60 months. A nomogram was developed by logistic regression to explore factors associated with long-term RBF.

RESULTS

Of the 443 T1D patients (mean [±SD] age 20.28 ± 5.50 years; mean [±SD] diabetes duration 28.5 ± 14.6 months), RBF was preserved in 64.3%. Independent predictors for poor RBF outcome among the 110 patients in the follow-up cohort were age at onset (odds ratio [OR] 0.82; 95% confidence interval [CI] 0.73-0.92; P < 0.001), high-risk human leukocyte antigen (HLA) status (OR 4.73; CI 1.28-17.52; P = 0.020), female sex (OR 3.39; CI 1.03-11.22; P = 0.045), and a history of diabetic ketoacidosis (DKA; OR 8.71; CI 2.31-32.83; P < 0.001). Baseline glutamic acid decarboxylase (GAD) antibody, family history of diabetes, body mass index, insulin dosage, and C-peptide and HbA1c levels were not associated with poor RBF outcome. Intensive glycemic control after T1D diagnosis may improve RBF within a mean (±SD) follow-up of 35.1 ± 13.8 months. The calibration plot for the probability of 2-, 3-, and 4-year RBF showed optimal agreement between nomogram-predicted and actual observed probabilities.

CONCLUSIONS

Younger age of onset, female sex, higher HLA risk status, and a history of DKA were the main factors predicting long-term poor preserved β-cell function. Glycemic control could improve RBF during the course of diabetes. The nomogram provides an individualized risk estimate of RBF in patients with newly diagnosed T1D within Chinese Han populations.

A systematic review of non-genetic predictors and genetic factors of glycated haemoglobin in type 1 diabetes one year after diagnosis

Type 1 diabetes (T1D) results from autoimmune destruction of the pancreatic βcells. Although all T1D patients require daily administration of exogenous insulin, their insulin requirement to achieve good glycaemic control may vary significantly. Glycated haemoglobin (HbA1c) level represents a stable indicator of glycaemic control and is a reliable predictor of long-term complications of T1D. The purpose of this article is to systematically review the role of non-genetic predictors and genetic factors of HbA1c level in T1D patients after the first year of T1D, to exclude the honeymoon period. A total of 1974 articles published since January 2011 were identified and 78 were finally included in the analysis of non-genetic predictors. For genetic factors, a total of 277 articles were identified and 14 were included. The most significantly associated factors with HbA1c level are demographic (age, ethnicity, and socioeconomic status), personal (family characteristics, parental care, psychological traits...) and features related to T1D (duration of T1D, adherence to treatment …). Only a few studies have searched for genetic factors influencing HbA1c level, most of which focused on candidate genes using classical genetic statistical methods, with generally limited power and incomplete adjustment for confounding factors and multiple testing. Our review shows the complexity of explaining HbA1c level variations, which involves numerous correlated predictors. Overall, our review underlines the lack of studies investigating jointly genetic and non-genetic factors and their interactions to better understand factors influencing glycaemic control for T1D patients.

Potential of epigenetic therapies in non-cancerous conditions

There has been an explosion of knowledge in the epigenetics field in the past 20 years. The first epigenetic therapies have arrived in the clinic for cancer treatments. In contrast, much of the promise of epigenetic therapies for non-cancerous conditions remains in the laboratories. The current review will focus on the recent progress that has been made in understanding the pathogenic role of epigenetics in immune and inflammatory conditions, and how the knowledge may provide much needed new therapeutic targets for many autoimmune diseases. Dietary factors are increasingly recognized as potential modifiers of epigenetic marks that can influence health and diseases across generations. The current epigenomics revolution will almost certainly complement the explosion of personal genetics medicine to help guide treatment decisions and disease risk stratification.

Epigenetics in autoimmune diseases with focus on type 1 diabetes

Autoimmune diseases arise when the body mounts an immune response against 'self' cells and tissues causing inflammation and damage. It is commonly accepted that these diseases develop because of the interplay of genetic and environmental factors. Evidence for genetic factors includes the higher concordance of disease in monozygotic twins than in dizygotic twins. However, monozygotic twins may remain discordant for disease indicating a role for environmental factors. Environmental factors may alter gene expression via epigenetic mechanisms. This is particularly pertinent in type 1 diabetes in which DNA methylation and histone modifications have been associated with altered gene expression. The low disease concordance rate in adult-onset type 1 diabetes (<20%) suggests that environmental and epigenetic changes may play a predominant role. Defining the role of epigenetic changes could identify specific gene pathways and dysregulated expression of gene products that contribute to the pathogenesis of type 1 diabetes. This article reviews how epigenetic mechanisms may contribute to the development of autoimmune diseases with a focus on type 1 diabetes.

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.

C-peptide response and HLA genotypes in subjects with recent-onset type 1 diabetes after immunotherapy with DiaPep277: an exploratory study

OBJECTIVE

To investigate whether lower risk HLA class II genotypes would influence the efficacy of DiaPep277 therapy in protecting β-cell function evaluated by C-peptide secretion in recent-onset type 1 diabetic subjects.

RESEARCH DESIGN AND METHODS

Data were collected from type 1 diabetic subjects enrolled in multicenter phase II studies with a randomized, double-blind, and placebo-controlled design in whom fasting and stimulated C-peptide levels were measured. HLA genotypes were classified in high, moderate, and low risk categories.

RESULTS

A total of 146 subjects (aged 4.3 to 58.5 years) were enrolled, including 76 children (<18 years old) and 70 adults. At baseline, there was a significant increase in fasting, maximal, and area under the curve (AUC) C-peptide from high to moderate and low risk HLA genotypes in adults (P for trend <0.04) but not in children. Children showed a decrease of the three parameters over time regardless of therapy and HLA genotype. DiaPep277-treated adults with low risk genotype had significantly higher maximal and AUC C-peptide versus placebo at 12 months (0.04 ± 0.07 vs. -0.28 ± 0.09 nmol/L, P < 0.01, and 0.53 ± 1.3 vs. -4.59 ± 1.5 nmol/L, P < 0.05, respectively). In the moderate risk genotype group, Δmaximal and AUC C-peptide values were significantly higher in DiaPep277-treated versus placebo-treated patients (P < 0.01 and P < 0.05, respectively).

CONCLUSIONS

This exploratory study demonstrates that type 1 diabetic adults with low and moderate risk HLA genotypes benefit the most from intervention with DiaPep277; the only subgroup with an increase of C-peptide at 12 months after diagnosis was the low risk DiaPep277-treated subgroup.

Genetic association of HLA DQB1 with CD4+CD25+(high) T-cell apoptosis in type 1 diabetes

Type 1 diabetes (T1D) has a strong genetic component and the major locus lies in the HLA DQB1 region. We found earlier an increased apoptosis with decreased viability and function of the CD4+CD25+(high) T-cell subset (Treg) in human subjects with recent-onset T1D and in multiple autoantibody-positive, high at-risk individuals. Tregs normally inhibit or delay onset of T1D in animal models and increased Treg apoptosis could bring on or accelerate disease from effector T-cell-mediated destruction of insulin-producing beta cells. In this study, we test the hypothesis that HLA DQB1 genotypes are associated with increased CD4+CD25+(high) T-cell apoptosis. HLA DQ-based genetic risk status was significantly associated with CD4+CD25+(high) T-cell apoptosis, after adjustment for age, gender and phenotypic status (n=83, F=4.04 (d.f.=3), P=0.01). Unaffected, autoantibody-negative high risk HLA DQB1 control subjects showed increased CD4+CD25+(high) apoptosis levels compared with low risk HLA DQB1 control subjects (n=26, P=0.002), confirming that the association precedes disease. The association of specific HLA DQB1 genotypes with Treg apoptosis was also tested, showing significance for HLA DQB1*0302, DQB1*0201 and HLA DQB1*0602 alleles. Our study shows an association of HLA DQB1 genotypes with CD4+CD25+(high) T-cell apoptosis, which implicates CD4+CD25+(high) T-cell apoptosis as a new intermediate trait for T1D.