HLA typing and immunological characterization of young-onset diabetes mellitus in a Hong Kong Chinese population

Risk of progressive chronic kidney disease in individuals with early-onset type 2 diabetes: a prospective cohort study

BACKGROUND

The progression trajectory of renal filtration function has not been well characterized in patients with early-onset type 2 diabetes mellitus (T2DM) although albuminuria is often reported in this population. We aim to study the risk of progressive chronic kidney disease (CKD) in individuals with early-onset T2DM.

METHODS

In total, 1189 T2DM participants were followed for 3.9 (interquartile range 3.2-4.7) years. Progressive CKD was defined as estimated glomerular filtration rate (eGFR) decline of ≥5 mL/min/1.73 m2 per year. Early-onset T2DM was defined as age at T2DM diagnosis between 18 and 30 years.

RESULTS

Compared with later-onset counterparts (N = 1032), participants with early-onset T2DM (N = 157) were more obese and had poorer glycaemic control at baseline. In the follow-up, 24.2% and 15.6% experienced progressive CKD in early-onset and later-onset participants, respectively (P = 0.007). Logistic regression suggested that participants with early-onset T2DM had 2.63-fold [95% confidence interval (CI) 1.46-4.75] higher risk of progressive CKD after accounting for multiple traditional risk factors. Furthermore, the excess risk of progressive CKD associated with early-onset T2DM mainly occurred in participants with preserved renal function [eGFR ≥60 mL/min/1.73 m2, odds ratio (OR) 2.85, 95% CI 1.50-5.42] and was more pronounced in those with diabetes duration <10 years (OR 3.67, 95% CI 1.51-8.90).

CONCLUSIONS

Individuals with early-onset T2DM have a higher risk of progressive CKD. The excess risk mainly exhibits in early stage of CKD and cannot be solely attributed to traditional risk factors and a longer diabetes duration.

Clinical heterogeneity of type 1 diabetes (T1D) found in Asia

Diabetes mellitus among young patients in Asia is caused by a complex set of factors. Although type 1 diabetes (T1D) remains the most common form of diabetes in children, the recent unabated increase in obesity has resulted in the emergence of type 2 diabetes (T2D) as a new type of diabetes among adolescents and young adults. In addition to the typical autoimmune type 1 diabetes (T1aD) and T2D patients, there is a variable incidence of cases of non-autoimmune types of T1D associated with insulin deficiency (T1bD). Additional forms have been described, including fulminant T1D (FT1D). Although most diagnoses of T1D are classified as T1aD, fulminant T1D exists as a hyper-acute subtype of T1D that affects older children, without associated autoimmunity. Patient with this rare aetiology of diabetes showed a complete loss of β-cell secretory capacity without evidence of recovery, necessitating long-term treatment with insulin. In addition, latent autoimmune diabetes in adults is a form of autoimmune-mediated diabetes, usually diagnosed during the insulin-dependent stage that follows a non-insulin requiring phase, which can be diagnosed earlier based on anti-islet autoantibody positivity. Some reports discuss T1bD. Others are elaborating on the presence of "atypical T1b diabetes," such as Flatbush diabetes. The prevalence of diabetes mellitus in young adults continues to rise in Asian populations as T2D increases. With improved characterization of patients with diabetes, the range of diabetic subgroups will become even more diverse in the future. Distinguishing T1D, T2D, and other forms of diabetes in young patients is challenging in Asian populations, as the correct diagnosis is clinically important and has implications for prognosis and management. Despite aetiological heterogeneity in the usual clinical setting, early diagnosis and classification of patients with diabetes relying on clinical grounds as well as measuring islet autoantibodies and fasting plasma C-peptide could provide a possible viable method to minimize complications.

Clinical profile of diabetic ketoacidosis in tertiary hospitals in China: a multicentre, clinic-based study

AIMS

To evaluate the clinical profile of patients with diabetic ketoacidosis in tertiary hospitals in China.

METHODS

A retrospective study of patients hospitalized with diabetic ketoacidosis between 2010 and 2012 was carried out in 15 tertiary hospitals around China. Clinical and laboratory data were collected. Patients were classified based on clinical diagnosis and treatment history. Groups were compared for differences in vital statistics and biochemical profiles at presentation.

RESULTS

The study comprised 643 patients with diabetic ketoacidosis: 308 patients (47.9%) with Type 1 diabetes, 294 patients (45.7%) with Type 2 diabetes and 41 patients (6.4%) with atypical diabetes. Three hundred and eighty-eight diabetic ketoacidosis episodes (60.3%) were in patients with known diabetes. The most common precipitating factor was infection (40.1%), followed by unknown causes (36.9%) and non-compliance with anti-diabetes treatment (16.8%). At presentation, gastrointestinal symptoms and dehydration were more common in the Type 1 diabetes group. For new-onset diabetes, only 74.4% and 55.9% of patients were evaluated for β-cell function and autoantibodies for classification. Only 67% of patients with diabetic ketoacidosis received appropriate fluid therapy and 56% patients with severe acidosis received bicarbonate therapy. The length of hospital stay was 10.0 (7.0-14.0) days. The mortality rate was 1.7%, and was much higher in Type 2 diabetes than that in Type 1 diabetes (3.2% vs. 0.4%, P < 0.01).

CONCLUSIONS

Type 2 and Type 1 diabetes contribute to a similar proportion of cases presenting with diabetic ketoacidosis in China. Admissions with diabetic ketoacidosis are still associated with significant mortality and prolonged hospitalization. The efficiency of diabetic ketoacidosis management needs to be improved by implementing the updated guidelines.

Autoimmune aspects of type 2 diabetes mellitus - a mini-review

Autoimmunity is a well-known pathogenic component in type 1 diabetes (T1DM). The assumption that the pathogenesis of type 2 diabetes (T2DM) also encompasses autoimmune aspects is recognized increasingly, based on the presence of circulating autoantibodies against β cells, self-reactive T cells, but also on the glucose-lowering efficacy of some immunomodulatory therapies in T2DM. The identification of these autoantibodies in elderly patients with slowly progressive manifestation of diabetes led to the introduction of a distinct clinical entity termed latent autoimmune diabetes of the adult (LADA), which combines features of both T1DM and T2DM. The autoantibody cluster differs in patients with LADA from patients with T1DM, but their presence indicates steady progression towards β-cell death and subsequent need for initiation of insulin treatment in a shorter period of time compared to autoantibody-negative T2DM patients. Autoimmune aspects in T2DM are not solely restricted to autoantibodies and thus LADA. They include the self-reactive T cells or defects in regulatory T cells (Tregs), which have been detected in autoantibody-negative T2DM patients as well. One contributor to the autoimmune activation in T2DM seems to be the chronic inflammatory state, characteristic of this disease. Upon inflammation-induced tissue destruction, cryptic 'self' antigens can trigger an autoimmune response, which in turn accelerates β-cell death. Both innate and adaptive immune system components, specifically macrophages and self-reactive T cells, contribute to an increased secretion of inflammatory cytokines involved in inflammatory and autoimmune processes. However, the extent to which inflammation overlaps with autoimmunity is not known. Our review focuses on autoimmune involvement in T2DM, with an emphasis on LADA and the humoral immune response, on the involvement of chronic inflammation in autoimmunity, and specifically the role of B and T cells as links between inflammatory and autoimmune reactions. We will further stress the consequences of autoimmune activation for T2DM patients and present novel therapeutic approaches for T2DM management that rely on immune modulation.

Prospective study on the incidences of cardiovascular-renal complications in Chinese patients with young-onset type 1 and type 2 diabetes

OBJECTIVE We examined metabolic profiles and cardiovascular-renal outcomes in a prospective cohort of Chinese patients with young-onset diabetes defined by diagnosis age <40 years. Patients with type 1 diabetes and normal-weight (BMI <23 kg/m(2)) and overweight (BMI ≥23 kg/m(2)) patients with type 2 diabetes were compared. RESEARCH DESIGN AND METHODS Between 1995 and 2004, 2,323 patients (type 1 diabetes, n = 209; normal-weight type 2 diabetes, n = 636; and overweight type 2 diabetes, n = 1,478) underwent detailed clinical assessment. Incident cardiovascular disease (CVD) including coronary heart disease, stroke, and peripheral vascular disease were identified using hospital discharge diagnoses. End-stage renal disease (ESRD) was defined by glomerular filtration rate <15 mL/min/1.73 m(2) or dialysis. RESULTS Overweight patients with type 2 diabetes had the worst metabolic profile and highest prevalence of microvascular complications. Over a median follow-up of 9.3 years, incidences of CVD were 0.6, 5.1, and 9.6 per 1,000 person-years in patients with type 1 diabetes, normal-weight patients with type 2 diabetes, and overweight patients with type 2 diabetes. The respective figures for ESRD were 2.2, 6.4, and 8.4 per 1,000 person-years. Compared with type 1 diabetes, the overweight type 2 diabetes group had a greater hazard of progression to CVD (hazard ratio [HR] 15.3 [95% CI 2.1-112.4]) and ESRD (HR 5.4 [95% CI 1.8-15.9]), adjusted for age, sex, and disease duration. The association became nonsignificant upon additional adjustment for BMI, blood pressure, and lipid. CONCLUSIONS Young patients with type 2 diabetes had greater risks of developing cardiovascular-renal complications compared with patients with type 1 diabetes. The increased risk was driven primarily by accompanying metabolic risk factors.

HLA-DRB, -DQA, and DQB alleles and haplotypes in Iranian patients with diabetes mellitus type I

Specific alleles at the HLA-DRB1, -DQA1, and -DQB1 loci seem to be associated with variable risks of developing type 1 diabetes (T1D). This study assessed the distribution of HLA-DR and -DQ alleles among Iranian T1D patients and healthy controls. In this study, HLA-DRB1, -DQA1, and -DQB1 alleles were determined in 100 children with T1D and 100 unrelated healthy controls. The following alleles were found to have a strong positive association with T1D: DRB1*0301, DRB1*0401, DRB1*0402, DQA1*0301, DQA1*0501, DQB1*0201, and DQB1*0302. Meanwhile, protective associations were found for DRB1*1001, DRB1*1101, DRB1*15, DRB1*16, DQA1*0102, DQA1*0103, DQB1*0301, DQB1*0501, and DQB1*0602 alleles. The haplotypes found most frequently among patients with T1D were DRB1*0301-DQA1*0501-DQB1*0201, DRB1*0401-DQA1*0301- DQB1*0302, and DRB1*0402-DQA1*0301-DQB1*0302, whereas DRB1*1101-DQA1*0501-DQB1*0301 and DRB1*16-DQA1*0102- DQB1*0501 haplotypes were negatively associated with the disease. These results confirm the previously reported association of specific HLA-DR and HLA-DQ alleles and haplotypes with T1D in Iranian population. The notable difference was the identification of DRB1*16-DQA1*0102-DQB1*0501 as a protective haplotype and the absence of a negative association of DRB1*1301-DQA1*0103-DRB1*0603 with T1D.

Different accelerators to early-onset Type 2 diabetes: a comparison of Anglo-Celtic and Chinese patients

AIMS

The "accelerator hypothesis" postulates that metabolic syndrome (MS) factors-overweight and insulin resistance-increase functional demand on islets, accelerating diabetes onset to a younger age in both Type 1 and Type 2 diabetes (T2DM). Previous research has focused only on the former. We examine to what extent the MS and individual components are accelerators to the earlier onset of T2DM in Anglo-Celtic and Chinese populations.

METHODS

A cross-sectional study of 1016 Anglo-Celtic and 1514 Chinese patients with recent-onset diabetes (duration <2 years) evaluated over a 12-year period. The MS syndrome and components were analyzed after stratification by age at presentation.

RESULTS

The Anglo-Celtic group shows a high prevalence of MS in early-onset disease and a striking inverse relationship of body mass index (BMI) with age at presentation. For every increase in BMI of 1 kg/m(2), there is a reduction in the age of presentation by 0.5 years (r=-0.3; P<.0001) .Younger groups had a higher prevalence of insulin resistance, elevated triglyceride (Tg), and low high-density lipoprotein cholesterol (HDL-C) (P<.0001 for trend for all three indices). In contrast, the Chinese group showed no relationship between age of presentation with BMI, insulin resistance, Tg, or HDL-C.

CONCLUSIONS

MS factors are important accelerators for T2DM in the Anglo-Celtic but not the Chinese population. This suggests that earlier onset of pancreatic beta cell deficiency is more important as an accelerator of diabetes presentation in Chinese. These data confirm the heterogeneity of T2DM and support the need for more ethnic specific strategies in diabetes prevention.

HLA-DRB1*08 allele may help to distinguish between type 1 diabetes mellitus and type 2 diabetes mellitus in Mexican children

BACKGROUND

It may be difficult to distinguish type 1 diabetes mellitus (T1DM) from type 2 diabetes mellitus (T2DM) in the pediatric population. Autoantibodies may help to differentiate both types of diabetes, but sometimes these are positive in patients with T2DM and negative in patients with T1DM. The human leukocyte antigen (HLA)-DR genotype has been associated with T1DM and with T2DM only in adults and in determined cases.

AIM

To determine the differences in HLA class II allele frequencies in Mexican children with T1DM and T2DM.

METHODS

We included 72 children with T1DM, 28 children with T2DM, and 99 healthy controls. All were Mexican, and diabetes was diagnosed according to the clinical and laboratory criteria established by the Expert Committee on the Diagnosis and Classification of Diabetes Mellitus. The HLA-DRB1 typing was performed using polymerase chain reaction-sequence-specific oligonucleotide probe and polymerase chain reaction sequence-specific primers.

RESULTS

We found an increased frequency of HLA-DRB1*08 and a decreased frequency of HLA-DRB1*04 in the group with T2DM vs. T1DM [p = 0.0001, odds ratio (OR) = 10.58, 95% confidence interval (CI) = 3-40.8 and p = 0.0006, OR = 0.24, 95% CI = 0.11-0.53, respectively]. No significant differences were found between HLA-DRB1 alleles in T2DM vs. controls. In the group with T1DM, there was a significantly increased frequency of the HLA-DR4 and HLA-DR3 alleles relative to controls (p = 0.0000001, OR = 3.59, 95% CI = 2.2-5.8 and p = 0.00009, OR = 4.66, 95% CI = 2.1-10.3, respectively).

CONCLUSION

There are significant differences in the HLA profile in Mexican children with T1DM and T2DM. HLA typing could play a role in the differentiation between both types of diabetes in this population.