The presence of GAD and IA-2 antibodies in youth with a type 2 diabetes phenotype: results from the TODAY study

Rising incidence and challenges of childhood diabetes. A mini review

Approximately 215,000 people younger than 20 yr of age, or 1 in 500 children and adolescents, had diabetes in the United States in 2010--and the incidence is rising. We still have insufficient knowledge about the precise mechanisms leading to the autoimmune mediated β-cell destruction in Type 1 diabetes, and the β-cell failure associated with insulin resistance in Type 2 diabetes. Long-term complications are similar: micro- and macrovascular disease occurs prematurely and presents an enormous burden on affected individuals, often as early as in middle age. In Type 1 diabetes, technological advances have clearly improved blood glucose management, but chronic peripheral over-insulinization remains a problem even with the most advanced systems. Thus, in Type 1 diabetes our research must focus on 1) finding the stimulus that ignites the immune response and 2) developing treatments that avoid hyperinsulinemia. In Type 2 diabetes in youth, the challenges start much earlier: most young patients do not even benefit from existing therapies due to non-compliance. Therefore, prevention of Type 2 diabetes and improvement of compliance, especially with non-pharmacological interventions, are the greatest challenges.

Controversies on how diabetes is diagnosed

PURPOSE OF REVIEW

To evaluate the controversial aspects of diabetes diagnosis.

RECENT FINDINGS

Within the past 2 years, revised guidelines for the diagnosis of diabetes have been issued which endorse the use of the hemoglobin A1C as a diagnostic test, in addition to the previously recommended tests. Updated diagnostic criteria for gestational diabetes were also published in the same period. Recent publications on the current role of oral glucose tolerance tests and diagnosis of diabetes in the acutely ill are sparse. There are new recommendations regarding the use of genetic testing and antibody testing in establishing the cause of diabetes.

SUMMARY

The inclusion of A1C as a diagnostic test has many advantages including reproducibility of the test and convenience, but there are situations where the test is unreliable and it misses many individuals who would have been diagnosed by plasma glucose testing. The diagnostic threshold of 6.5% for the A1C remains controversial. There is still no consensus on the best approach to diagnose gestational diabetes. The role of the oral glucose tolerance test seems to be diminishing. Diagnosis of diabetes in acute illness is aided by A1C testing. Genetic and autoantibody testing in specific situations offer diagnostic and therapeutic utility.

Type 2 diabetes in childhood: clinical characteristics and role of β-cell autoimmunity

The global obesity epidemic has led to dramatic increases in the incidence and prevalence of type 2 diabetes mellitus (T2DM) among youth worldwide. In today's clinical practice it has become increasingly difficult to distinguish type 1 diabetes mellitus (T1DM) from T2DM as many children with T1DM are overweight at diagnosis. Numerous recent publications note a significant proportion of physician-diagnosed T2DM youth with evidence of pancreatic autoimmunity, exemplifying the challenges in distinguishing between T1DM and T2DM. The clinical implications of the phenomenon of antibody positivity in phenotypic T2DM youth, also referred to as "type 1.5 diabetes" (T1.5 DM), "double diabetes," "latent autoimmune diabetes in youth" (LADY), and "hybrid diabetes," are unclear at present. Current and future work should determine if the presence of autoantibodies in phenotypic T2DM youth/children affects clinical course; this will facilitate the development of optimal treatment strategies.

Long term effects of the implantation of autologous bone marrow mononuclear cells for type 2 diabetes mellitus

Previous studies have shown that several types of stem cells can differentiate into insulin-secreting islet beta-cells and that these cells can reduce blood glucose in some trials, but there has been no report of a long-term follow-up. We assessed the long-term effects of the use of autologous bone marrow mononuclear cells in the treatment of type 2 diabetes mellitus (T2DM). Based on the willingness to receive implantation of bone marrow mononuclear cells, One hundred and eighteen patients with T2DM were divided into two groups; the patients in group I were treated with autologous bone marrow mononuclear cells and patients in group II were treated with insulin intensification therapy. Mononuclear cells from bone marrow were injected back into the patient's pancreas via a catheter. Patients were followed-up after the operation at monthly intervals for the first 3 months and thereafter every 3 months for the next 33 months, the occurrence of any side effects and the results of laboratory examinations were evaluated. There were no reported acute or chronic side effects in group I and both the HbA1c and C-peptide in group I patients were significantly better than either pretherapy values or group II patients during the follow-up period. These data suggested that the implantation of autologous bone marrow mononuclear cells for the treatment of T2DM is safe and effective. This therapy can partially restore the function of islet beta-cells and maintain blood glucose homeostasis in a longer time.

Reclassification of diabetes type in pediatric patients initially classified as type 2 diabetes mellitus: 15 years follow-up using routine data from the German/Austrian DPV database

OBJECTIVE

To examine change of diagnosis in patients from the German/Austrian multicenter DPV (Diabetes Patienten Verlaufsdokumentation) database initially classified as type 2 diabetes.

METHODS

Patients aged ≤20 years at onset, diagnosed between 1995 and 2010 were followed for at least 6 months. Chi-square/Wilcoxon tests were performed to compare patient groups according to diabetes type after reclassification.

RESULTS

From 580 study patients, 60 (10.3%) were reclassified, on average 2.4 years after initial diagnosis as follows: 23 (38.3%) as type 1 diabetes; 9 (15%) as maturity onset diabetes of the young (MODY); 20 (33.3%) as "other specific diabetes forms" and 8 (13.3%) as "remission" of type 2 diabetes. Patients reclassified to type 1 were significantly younger (13.5 ± 2.9 versus 14.0 ± 2.6; p=0.027) and more often β-cell antibody positive at disease onset (80.0% versus 31.2%; p=0.002), while patients reclassified as MODY had significantly lower BMI-SDS values than 520 patients with confirmed type 2 diabetes (2.5 ± 1.1 versus 0.9 ± 1.1; p<0.001). The latter were also considerably more obese than patients in "remission" and those reclassified to "other specific diabetes forms".

CONCLUSION

About 10% of patients in the DPV database, initially diagnosed as type 2 diabetes, were retrospectively reclassified.

Diabetes and insulin resistance in pediatric obesity

Over the past 2 decades, the prevalence of obesity and type 2 diabetes mellitus (T2DM) in children and adolescents has risen to epidemic proportions and disproportionately affects racial and ethnic minorities, who are at greater risk. The pathophysiology of T2DM is complex and involves insulin resistance, pancreatic β-cell dysfunction, and visceral adiposity. Current treatments of T2DM are limited to lifestyle intervention, metformin, and insulin therapy; use of these strategies in combination is often most effective. The role of research is to uncover simple biomarkers for insulin sensitivity and optimal and innovative treatment of insulin resistance and T2DM.

Pre-diabetes in Italian obese children and youngsters

BACKGROUND AND AIM

Metabolic characteristics and rate of progression to overt Type 2 diabetes (T2D) in low-risk European obese children are not well documented. Aim of the study was to investigate differences in insulin sensitivity and secretion in Italian obese children and youngsters with pre-diabetes.

METHODS

Ninety-six obese children and youngsters with pre-diabetes, pair-matched with individuals with normal glucose tolerance (NGT) were included in the present study. Participants were screened by oral glucose tolerance. Pre-diabetes was classified as impaired fasting glucose (IFG), impaired glucose tolerance (IGT) and combined IFG-IGT. Homeostasis model assessment of insulin resistance (HOMA-IR), 2-h insulin, insulin sensitivity index (ISI) and disposition index (DI) were calculated to estimate fasting, peripheral and whole body insulin sensitivity and capacity of pancreatic islets to compensate for lower insulin sensitivity, respectively. One-way analysis of variance was used to compare groups.

RESULTS

Eleven subjects had IFG (11.5%), 79 IGT (82.3%), 6 combined IFG-IGT (6.3%). Individuals with IFG showed the highest HOMA-IR (p=0.0007), those with IGT the highest 2-h insulin (p<0.0001), those with IFG-IGT the lowest ISI (p<0.0001), with severely reduced DI (p=0.0003). Compared with NGT, DI was 60% lower in those with IFG-IGT.

CONCLUSION

IFG is linked primarily to fasting insulin resistance, IGT to peripheral insulin resistance. IFG-IGT is hallmarked by reduced whole body insulin sensitivity and an additional severe defect in DI. Further longitudinal studies are needed to understand whether the different categories of pre-diabetes in European obese adolescents represent real pre-diabetic alterations.

Successful modulation of type 2 diabetes in db/db mice with intra-bone marrow--bone marrow transplantation plus concurrent thymic transplantation

There is increasing evidence that both autoimmune and autoinflammatory mechanisms are involved in the development of not only type 1 diabetes mellitus (T1 DM), but also type 2 diabetes mellitus (T2 DM). Our laboratory has focused on this concept, and in earlier efforts replaced the bone marrow cells (BMCs) of leptin receptor-deficient (db/db) mice, an animal model of T2DM, with those of normal C57BL/6 (B6) mice by IBM-BMT. However, the outcome was poor due to incomplete recovery of T cell function. Therefore, we hypothesized that intra-bone marrow-bone marrow transplantation plus thymus transplantation (IBM-BMT + TT) could be used to treat T2 DM by normalizing the T cell imbalance. Hence we addressed this issue by using such dual transplantation and demonstrate herein that seven weeks later, recipient db/db mice manifested improved body weight, reduced levels of blood glucose, and a reduction of plasma IL-6 and IL-1β. More importantly, this treatment regimen showed normal CD4/CD8 ratios, and increased plasma adiponectin levels, insulin sensitivity, and the number of insulin-producing cells. Furthermore, the expression of pancreatic pAKT, pLKB1, pAMPK and HO-1 was increased in the mice treated with IBM-BMT + TT. Our data show that IBM-BMT + TT treatment normalizes T cell subsets, cytokine imbalance and insulin sensitivity in the db/db mouse, suggesting that IBM-BMT + TT is a viable therapeutic option in the treatment of T2 DM.

Characteristics of adolescents and youth with recent-onset type 2 diabetes: the TODAY cohort at baseline

CONTEXT

The Treatment Options for Type 2 Diabetes in Adolescents and Youth (TODAY) cohort represents the largest and best-characterized national sample of American youth with recent-onset type 2 diabetes.

OBJECTIVE

The objective of the study was to describe the baseline characteristics of participants in the TODAY randomized clinical trial.

DESIGN

Participants were recruited over 4 yr at 15 clinical centers in the United States (n = 704) and enrolled, randomized, treated, and followed up 2-6 yr.

SETTING

The study was conducted at pediatric diabetes care clinics and practices.

PARTICIPANTS

Eligible participants were aged 10-17 yr inclusive, diagnosed with type 2 diabetes for less than 2 yr and had a body mass index at the 85th percentile or greater.

INTERVENTIONS

After baseline data collection, participants were randomized to one of the following groups: 1) metformin alone, 2) metformin plus rosiglitazone, or 3) metformin plus a lifestyle program of weight management.

MAIN OUTCOME MEASURES

Baseline data presented include demographics, clinical/medical history, biochemical measurements, and clinical and biochemical abnormalities.

RESULTS

At baseline the cohort included the following: 64.9% were female; mean age was 14.0 yr; mean diabetes duration was 7.8 months; mean body mass index Z-score was 2.15; 89.4% had a family history of diabetes; 41.1% were Hispanic, 31.5% were non-Hispanic black; 38.8% were living with both biological parents; 41.5% had a household annual income of less than $25,000; 26.3% had a highest education level of parent/guardian less than a high school degree; 26.3% had a blood pressure at the 90th percentile or greater; 13.6% had a blood pressure at the 95th percentile or greater; 13.0% had microalbuminuria; 79.8% had a low high-density lipoprotein level; and 10.2% had high triglycerides.

CONCLUSIONS

The TODAY cohort is predominantly from racial/ethnic minority groups, with low socioeconomic status and a family history of diabetes. Clinical and biochemical abnormalities and comorbidities are prevalent within 2 yr of diagnosis. These findings contribute greatly to our understanding of American youth with type 2 diabetes.

Approach to the obese adolescent with new-onset diabetes

The prevalence of both type 1 and type 2 diabetes among children and adolescents has been steadily increasing over the last few decades. However, as the general pediatric population becomes more obese and more ethnically diverse, reliance on phenotypic characteristics for distinguishing between these types of diabetes is becoming increasingly untenable. Yet, the recognition of differences in treatment strategies, associated disorders, and both short- and long-term diabetes and cardiovascular outcomes supports the importance of diagnostic efforts to make a distinction between diabetes types. An approach to determination of diabetes type is discussed, focused on the presence or absence of autoimmunity and assessment of β-cell function. At the time of diagnosis, it is generally not possible to be certain of diabetes type, and therefore, initial treatment decisions must be made based on aspects of the presenting physiology, with adjustments in treatment approach made as the individual's course proceeds and additional information becomes available. The apparent overlap between type 1 and type 2 diabetes that occurs in obese adolescents has resulted in some controversy regarding mixed forms of diabetes that are ultimately semantic, but this does raise interesting questions about the treatment of type 1 diabetes in the presence of an insulin-resistant phenotype. Finally, the lack of information about the efficacy of treatment of cardiovascular risk factors, such as dyslipidemia and hypertension, along with the well-documented challenges in adherence to chronic illness treatment in this population, creates substantial challenges.