C-peptide in juvenile diabetics beyond the postinitial remission period. Relation to clinical manifestations at onset of diabetes, remission and diabetic control

Glutamic acid decarboxylase immunotherapy for type 1 diabetes

PURPOSE OF REVIEW

To describe recent development of an autoantigen (GAD) treatment towards well tolerated and efficacious precision medicine in type 1 diabetes.

RECENT FINDINGS

Although subcutaneous GAD-alum treatment failed to reach primary endpoint in a phase III trial, metanalyses showed a 97% probability of efficacy, and clear efficacy in patients carrying Hyman Leucoycte Antigen (HLA) DR3DQ2. Efforts have been made to improve efficacy by trying combination therapies with vitamin D + Ibuprofen resp vitamin D + Etanercept (TNF-α inhibition), without any breakthrough until the administration of GAD-alum was changed from subcutaneous to intralymphatic. With a very small dose of GAD-alum (4 μg) given into an inguinal lymph three times with 1 month interval, the efficacy in patients with HLADR3DQ2 has been impressive, with significantly better beta cell preservation than patients who got placebo in a double-blind randomized trial, and clinical efficacy with more patients in partial remission (IDAA1c < 9) and larger proportion of patients with CGM-measured blood glucose Time In Range (TIR), significantly correlated to the C-peptide values. The treatment has been easy for patients and healthcare without treatment-related risk or adverse events.

SUMMARY

Intralymphatic GAD-alum treatment in type 1 diabetes patients carrying HLA DR3DQ2 seems to be an attractive immune intervention.

Diagnosis and treatment of type 1 diabetes at the dawn of the personalized medicine era

Type 1 diabetes affects millions of people globally and requires careful management to avoid serious long-term complications, including heart and kidney disease, stroke, and loss of sight. The type 1 diabetes patient cohort is highly heterogeneous, with individuals presenting with disease at different stages and severities, arising from distinct etiologies, and overlaying varied genetic backgrounds. At present, the “one-size-fits-all” treatment for type 1 diabetes is exogenic insulin substitution therapy, but this approach fails to achieve optimal blood glucose control in many individuals. With advances in our understanding of early-stage diabetes development, diabetes stratification, and the role of genetics, type 1 diabetes is a promising candidate for a personalized medicine approach, which aims to apply “the right therapy at the right time, to the right patient”. In the case of type 1 diabetes, great efforts are now being focused on risk stratification for diabetes development to enable pre-clinical detection, and the application of treatments such as gene therapy, to prevent pancreatic destruction in a sub-set of patients. Alongside this, breakthroughs in stem cell therapies hold great promise for the regeneration of pancreatic tissues in some individuals. Here we review the recent initiatives in the field of personalized medicine for type 1 diabetes, including the latest discoveries in stem cell and gene therapy for the disease, and current obstacles that must be overcome before the dream of personalized medicine for all type 1 diabetes patients can be realized.

Pancreatic islet reserve in type 1 diabetes

Type 1 diabetes (T1D) is a chronic autoimmune disease characterized by pancreatic islet β cell loss and dysfunction resulting in insulin deficiency and hyperglycemia. During a presymptomatic phase of established β cell autoimmunity, β cell loss may first be evident through assessment of β cell secretory capacity, a measure of functional β cell mass. Reduction in pancreatic islet β cell reserve eventually manifests as impaired first-phase insulin response to glucose and abnormal glucose tolerance, which progresses until the functional capacity for β cell secretion can no longer meet the demand for insulin to control glycemia. A functional β cell mass of ∼25% of normal may be required to avoid symptomatic T1D but is already associated with dysregulated glucagon secretion. With symptomatic T1D, stimulated C-peptide levels >0.60 ng/mL (0.200 pmol/mL) indicate the presence of clinically meaningful residual β cell function for contributing to glycemic control, although even higher residual C-peptide appears necessary for evidencing glucose-dependent islet β and α cell function that may contribute to maintaining (near)normal glycemia. β cell replacement by islet transplantation can restore a physiologic reserve capacity for insulin secretion, confirming thresholds for functional β cell mass required for independence from insulin therapy.

Lower Insulin-Dose Adjusted A1c (IDAA1c) Is Associated With Less Complications in Individuals With Type 1 Diabetes Treated With Hematopoetic Stem-Cell Transplantation and Conventional Therapy

Objective: To evaluate the association between insulin-dose adjusted A1C (IDAA1c) and microvascular complications (MC) and hypoglycemia in a representative Brazilian population of Type 1 diabetes mellitus (T1DM) patients. Research Design and Methods: This was a cross-sectional study based on a previous study, "Microvascular Complications in Type 1 Diabetes: a comparative analysis of patients treated with autologous nonmyeloablative hematopoietic stem-cell transplantation (AHST) and conventional medical therapy (CT)". The 168 patients in that study (144 from CT plus 24 from AHST) were re-subdivided into two groups, according to their IDAA1c values (30 patients had IDAA1c ≤ 9; 138 had IDAA1c > 9). Then, the prevalence of MC (diabetic renal disease, neuropathy, and retinopathy), hypoglycemia (blood glucose <60 mg/dL), and severe hypoglycemic (episode of hypoglycemia that required the assistance of another person to treat) events were compared between the groups. The groups were well-matched on these factors: duration of disease, sex, and age at the time of diagnosis of T1DM. Results: After an average of 8 years after diagnosis, only 6.6% (2/30) of the patients from IDAA1c ≤ 9 group developed any MC, whereas 21.0% (29/138) from the IDAA1c > 9 group had at least one complication (p = 0.044). Regarding hypoglycemic events, the proportion of individuals who reported at least 1 episode of hypoglycemia in the last month was 43.3 and 64.7% from the IDAA1c ≤ 9 and IDAA1c > 9 groups, respectively (p = 0.030). Regarding severe hypoglycemia, the proportion of patients presenting at least one episode in the last month and the rate of episode/patient/month were similar between groups (6.7 vs. 13.2%; p = 0.535; and 0.1/patient/month vs. 0.25/patient/month; p = 0.321). Conclusion: In a representative Brazilian population of T1DM patients, those with IDAA1c ≤ 9 presented a lower frequency of MC, as well as fewer episodes of hypoglycemia, in the month prior to the analysis.

Beta cell function after intensive subcutaneous insulin therapy or intravenous insulin infusion at onset of type 1 diabetes in children without ketoacidosis

BACKGROUND

Our aim was to see if IV insulin therapy at diagnosis preserves beta-cell function better than multiple subcutaneous (SC) injections.

METHODS

Fifty-four children 9.9 ± 3.5 years (range 2.8-14.9) without ketoacidosis were included in a 2 years, randomized multicenter study with insulin SC or 48 to 72 hours IV initially. Thirty-three (61%) were boys, 22 (41%) were pubertal. Forty-eight subjects completed 12 months follow-up and 43 completed 24 months. At 1, 6, 12, and 24 months, hemoglobin A1c (HbA1c), C-peptide and insulin/kg/24 h were measured. At 24 months, a mixed-meal tolerance test (MMTT) was performed.

RESULTS

HbA1c at diagnosis was 10.7%, (93 mmol/mol) for IV, 10.7%, (94 mmol/mol) for SC. During the first 2 full days of insulin therapy, mean plasma glucose was 8.2 mmol/L for IV, 9.5 for SC (P = .025). Mean insulin dose was 1.5 U/kg/d for IV vs 1.0 for SC (P = .001). Sixteen (7 in IV, 9 in SC group) started with insulin pumps during the follow-up. At 24 months, we saw no significant differences: HbA1c (7.5%, 58 mmol/mol, for IV, 7.2%, 55 mmol/mol, for SC; ns), insulin doses (0.79 vs 0.88 U/kg/d; ns), fasting C-peptide (0.08 vs 0.12 nmol/L; ns), maximal MMTT response (0.19 vs 0.25 nmol/L; ns) and AUC (18.26 vs 23.9 nmol/L*min; ns). Peak C-peptide >0.2 nmol/L in the combined IV and SC groups correlated significantly with HbA1c and C-peptide at onset in a multiple regression.

CONCLUSION

Residual beta cell function at 2 years seems to be independent from initial insulin regimens but related to HbA1c and C-peptide at onset.

Therapies to Preserve β-Cell Function in Type 1 Diabetes

In spite of modern techniques, the burden for patients with type 1 diabetes mellitus will not disappear, and type 1 diabetes will remain a life-threatening disease causing severe complications and increased mortality. We have to learn of ways to stop the destructive process, preserve residual insulin secretion or even improve the disease via β-cell regeneration. This will give a milder disease, a more stable metabolism, simpler treatment and perhaps even cure. Therapies based on single drugs have not shown sufficient efficacy; however, there are several treatments with encouraging efficacy and no apparent, or rather mild, adverse events. As the disease process is heterogeneous, treatments have to be chosen to fit relevant subgroups of patients, and step by step efficacy can possibly be improved by the use of combination therapies. Thus immunosuppressive therapies like anti-CD3 and anti-CD20 monoclonal antibodies might be combined with fusion proteins such as etanercept [tumor necrosis factor (TNF)-α inhibitor] and/or abatacept (CTLA4-Ig) early after onset to stop the destructive process, supported by β-cell protective agents. The effect may be prolonged by using autoantigen therapy [glutamate decarboxylase (GAD) proinsulin], and by adding agents facilitating β-cell regeneration [e.g. glucagon-like peptide-1 (GLP-1)] there should be a good chance to make the disease milder, perhaps leading to cure in some patients.

Urinary C-Peptide/Creatinine Ratio Can Distinguish Maturity-Onset Diabetes of the Young from Type 1 Diabetes in Children and Adolescents: A Single-Center Experience

BACKGROUND

The urinary C-peptide/creatinine ratio (UCPCR) and fasting C-peptide level can assess beta-cell function in clinical practice. In the present study, the use of the UCPCR and fasting C-peptide levels was investigated in the differential diagnosis between maturity-onset diabetes of the young (MODY) and type 1 diabetes mellitus (T1DM).

METHODS

Twenty-seven patients with genetically confirmed MODY by next-generation sequence analysis and 42 children with T1DM were included. C-peptide levels were measured after an overnight fast before breakfast, and urine samples were collected 2 h after a standard lunch in the hospital.

RESULTS

The UCPCR in the T1DM group was 0.17 ± 0.5 nmol/mmol, and in the MODY group it was 1.27 ± 1.03 nmol/mmol (p = 0.001). The receiver operating characteristic (ROC) curves showed excellent discrimination (area under the curve 0.93). A UCPCR ≥0.22 nmol/mmol yielded a 96.3% sensitivity and an 85.7% specificity. The fasting C-peptide level in the T1DM group was lower than that in the MODY group (p = 0.001). The fasting C-peptide cutoff determined by ROC curve analysis was 0.62 ng/ml, with a sensitivity of 93% and a specificity of 90% for discriminating between MODY and T1DM.

CONCLUSIONS

We showed that the UCPCR and fasting C-peptide levels in children and adolescents can distinguish patients with MODY from patients with T1DM with high specificity and sensitivity. A value of UCPCR ≥0.22 nmol/mmol may indicate further genetic testing for MODY.

Staging presymptomatic type 1 diabetes: a scientific statement of JDRF, the Endocrine Society, and the American Diabetes Association

Insights from prospective, longitudinal studies of individuals at risk for developing type 1 diabetes have demonstrated that the disease is a continuum that progresses sequentially at variable but predictable rates through distinct identifiable stages prior to the onset of symptoms. Stage 1 is defined as the presence of β-cell autoimmunity as evidenced by the presence of two or more islet autoantibodies with normoglycemia and is presymptomatic, stage 2 as the presence of β-cell autoimmunity with dysglycemia and is presymptomatic, and stage 3 as onset of symptomatic disease. Adoption of this staging classification provides a standardized taxonomy for type 1 diabetes and will aid the development of therapies and the design of clinical trials to prevent symptomatic disease, promote precision medicine, and provide a framework for an optimized benefit/risk ratio that will impact regulatory approval, reimbursement, and adoption of interventions in the early stages of type 1 diabetes to prevent symptomatic disease.

Function of Isolated Pancreatic Islets From Patients at Onset of Type 1 Diabetes: Insulin Secretion Can Be Restored After Some Days in a Nondiabetogenic Environment In Vitro: Results From the DiViD Study

The understanding of the etiology of type 1 diabetes (T1D) remains limited. One objective of the Diabetes Virus Detection (DiViD) study was to collect pancreatic tissue from living subjects shortly after the diagnosis of T1D. Here we report the insulin secretion ability by in vitro glucose perifusion and explore the expression of insulin pathway genes in isolated islets of Langerhans from these patients. Whole-genome RNA sequencing was performed on islets from six DiViD study patients and two organ donors who died at the onset of T1D, and the findings were compared with those from three nondiabetic organ donors. All human transcripts involved in the insulin pathway were present in the islets at the onset of T1D. Glucose-induced insulin secretion was present in some patients at the onset of T1D, and a perfectly normalized biphasic insulin release was obtained after some days in a nondiabetogenic environment in vitro. This indicates that the potential for endogenous insulin production is good, which could be taken advantage of if the disease process was reversed at diagnosis.

Home urine C-peptide creatinine ratio (UCPCR) testing can identify type 2 and MODY in pediatric diabetes

BACKGROUND

Making the correct diabetes diagnosis in children is crucial for lifelong management. Type 2 diabetes and maturity onset diabetes of the young (MODY) are seen in the pediatric setting, and can be difficult to discriminate from type 1 diabetes. Postprandial urinary C-peptide creatinine ratio (UCPCR) is a non-invasive measure of endogenous insulin secretion that has not been tested as a diagnostic tool in children or in patients with diabetes duration <5 yr. We aimed to assess whether UCPCR can discriminate type 1 diabetes from MODY and type 2 in pediatric diabetes.

METHODS

Two-hour postprandial UCPCR was measured in 264 patients aged <21 yr (type 1, n = 160; type 2, n = 41; and MODY, n = 63). Receiver operating characteristic curves were used to identify the optimal UCPCR cutoff for discriminating diabetes subtypes.

RESULTS

UCPCR was lower in type 1 diabetes [0.05 (<0.03-0.39) nmol/mmol median (interquartile range)] than in type 2 diabetes [4.01 (2.84-5.74) nmol/mmol, p < 0.0001] and MODY [3.51 (2.37-5.32) nmol/mmol, p < 0.0001]. UCPCR was similar in type 2 diabetes and MODY (p = 0.25), so patients were combined for subsequent analyses. After 2-yr duration, UCPCR ≥ 0.7 nmol/mmol has 100% sensitivity [95% confidence interval (CI): 92-100] and 97% specificity (95% CI: 91-99) for identifying non-type 1 (MODY + type 2 diabetes) from type 1 diabetes [area under the curve (AUC) 0.997]. UCPCR was poor at discriminating MODY from type 2 diabetes (AUC 0.57).

CONCLUSIONS

UCPCR testing can be used in diabetes duration greater than 2 yr to identify pediatric patients with non-type 1 diabetes. UCPCR testing is a practical non-invasive method for use in the pediatric outpatient setting.

Lessons from the mixed-meal tolerance test: use of 90-minute and fasting C-peptide in pediatric diabetes

OBJECTIVE

Mixed-meal tolerance test (MMTT) area under the curve C-peptide (AUC CP) is the gold-standard measure of endogenous insulin secretion in type 1 diabetes but is intensive and invasive to perform. The 90-min MMTT-stimulated CP ≥0.2 nmol/L (90CP) is related to improved clinical outcomes, and CP ≥0.1 nmol/L is the equivalent fasting measure (FCP). We assessed whether 90CP or FCP are alternatives to a full MMTT.

RESEARCH DESIGN AND METHODS

CP was measured during 1,334 MMTTs in 421 type 1 diabetes patients aged <18 years at 3, 9, 18, 48, and 72 months duration. We assessed: 1) correlation between mean AUC CP and 90CP or FCP; 2) sensitivity and specificity of 90CP ≥0.2 nmol/L and FCP ≥ 0.1 nmol/L to detect peak CP ≥0.2 nmol/L and the equivalent AUC CP; and 3) how the time taken to reach the CP peak varied with age of diagnosis and diabetes duration.

RESULTS

AUC CP was highly correlated to 90CP (r(s) = 0.96; P < 0.0001) and strongly correlated to FCP (r(s) = 0.84; P < 0.0001). AUC CP ≥23 nmol/L/150 min was the equivalent cutoff for peak CP ≥0.2 nmol/L (98% sensitivity/97% specificity). A 90CP ≥0.2 nmol/L correctly classified 96% patients using AUC or peak CP, whereas FCP ≥0.1 nmol/L classified 83 and 85% patients, respectively. There was only a small difference seen between peak and 90CP (median 0.02 nmol/L). The CP peak occurred earlier in patients with longer diabetes duration (6.1 min each 1-year increase in duration) and younger age (2.5 min each 1-year increase).

CONCLUSIONS

90CP is a highly sensitive and specific measure of AUC and peak CP in children and adolescents with type 1 diabetes and offers a practical alternative to a full MMTT.

Immune therapy in type 1 diabetes mellitus

Type 1 diabetes mellitus (T1DM) is an autoimmune disorder directed against the β cells of the pancreatic islets. The genetic risk of the disease is linked to HLA-DQ risk alleles and unknown environmental triggers. In most countries, only 10-15% of children or young adults newly diagnosed with T1DM have a first-degree relative with the disease. Autoantibodies against insulin, GAD65, IA-2 or the ZnT8 transporter mark islet autoimmunity. These islet autoantibodies may already have developed in children of 1-3 years of age. Immune therapy in T1DM is approached at three different stages. Primary prevention is treatment of individuals at increased genetic risk. For example, one trial is testing if hydrolyzed casein milk formula reduces T1DM incidence in genetically predisposed infants. Secondary prevention is targeted at individuals with persistent islet autoantibodies. Ongoing trials involve nonautoantigen-specific therapies, such as Bacillus Calmette-Guérin vaccine or anti-CD3 monoclonal antibodies, or autoantigen-specific therapies, including oral and nasal insulin or alum-formulated recombinant human GAD65. Trial interventions at onset of T1DM have also included nonautoantigen-specific approaches, and autoantigen-specific therapies, such as proinsulin peptides. Although long-term preservation of β-cell function has been difficult to achieve in many studies, considerable progress is being made through controlled clinical trials and animal investigations towards uncovering mechanisms of β-cell destruction. Novel therapies that prevent islet autoimmunity or halt progressive β-cell destruction are needed.

Which factors predict glycemic control in children diagnosed with type 1 diabetes before 6.5 years of age?

Predictors of long-term glycemic control and growth patterns in children diagnosed with type 1 diabetes (T1D) before 6.5 years of age were evaluated. One hundred seventy-three children (84 boys) with a mean diabetes duration of 4.9 ± 2.8 years participated in this observational study. Medical charts were reviewed for background, disease- and treatment-related parameters, and growth parameters. Study endpoints were HbA1c value, rates of severe hypoglycemia and diabetic ketoacidosis events, and growth patterns. Mean HbA1c for the total duration of diabetes (HbA1c-TDD) was 7.9 ± 0.8%. Comparison of the study variables between patients with HbA1c-TDD <7.5% (n = 53) or ≥7.5% yielded a significantly shorter duration of diabetes (P = 0.01) and lower rate of diabetic ketoacidosis (P = 0.02) in those with HbA1C-TDD <7.5%, without differences between these groups in age at diabetes onset, insulin regimens, daily glucose measurements, and rate of severe hypoglycemia. Factors significantly predicting achievement of the mean target HbA1c-TDD <7.5% were lower HbA1c at 0.5 years and 1 year after diabetes diagnosis (P = 0.002 and P < 0.001, respectively). Patients followed for at least 5 years (n = 48) showed a significant decrease in height-SDS (P < 0.001) and a significant increase in weight-SDS (P = 0.004) from diabetes diagnosis to the last follow-up visit, without a significant change in weight-SDS from 0.5 years after diagnosis to the last follow-up visit. Our results suggest that in patients with T1D diagnosed during the preschool-age, mean HbA1c level in the first year is a strong predictor of achieving target HbA1c level in the subsequent years, regardless the type of insulin regimen. This "metabolic tracking" emphasizes the importance of achieving early optimal control even in younger children.

Immune intervention in children with type 1 diabetes

Not only T cells but also B cells play a role in the autoimmune process. Both monoclonal antiCD3 and antiCD20 antibodies seem efficacious. However, such treatments need to be refined to minimize adverse events. Use of autoantigens to create tolerance is a concept with great potential. GAD65 treatment has shown efficacy without adverse events thus far, and administration of the insulin B chain shows interesting immunologic effects. Other more or less speculative approaches to modulate the immune process need further studies with good design. Risks that are too serious cannot be motivated. In addition, as the beta cells may die even though the autoimmune process is stopped, protective measures may be valuable (eg, active insulin treatment, and perhaps interleukin-1 receptor antagonists to reduce the nonautoimmune inflammation). Combination of immune intervention, protection of the beta cells, and stimulation of regeneration may lead to a milder disease or even a cure in the future, and prevention is no longer unrealistic.

The role of immunomodulation therapy in autoimmune diabetes

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

Glucose and C-peptide changes in the perionset period of type 1 diabetes in the Diabetes Prevention Trial-Type 1

OBJECTIVE

We examined metabolic changes in the period immediately after the diagnosis of type 1 diabetes and in the period leading up to its diagnosis in Diabetes Prevention Trial-Type 1 (DPT-1) participants.

RESEARCH DESIGN AND METHODS

The study included oral insulin trial participants and parenteral insulin trial control subjects (n = 63) in whom diabetes was diagnosed by a 2-h diabetic oral glucose tolerance test (OGTT) that was confirmed by another diabetic OGTT within 3 months. Differences in glucose and C-peptide levels between the OGTTs were assessed.

RESULTS

Glucose levels increased at 90 (P = 0.006) and 120 min (P < 0.001) from the initial diabetic OGTT to the confirmatory diabetic OGTT (mean +/- SD interval 5.5 +/- 2.8 weeks). Peak C-peptide levels fell substantially between the OGTTs (median change -14.3%, P < 0.001). Among the 55 individuals whose last nondiabetic OGTT was approximately 6 months before the initial diabetic OGTT, peak C-peptide levels decreased between these two OGTTs (median change -14.0%, P = 0.052). Among those same individuals the median change in peak C-peptide levels from the last normal OGTT to the confirmatory OGTT (interval 7.5 +/- 1.3 months) was -23.8% (P < 0.001). Median rates of change in peak C-peptide levels were 0.00 ng x ml(-1) x month(-1) (P = 0.468, n = 36) from approximately 12 to 6 months before diagnosis, -0.10 ng x ml(-1) x month(-1) (P = 0.059, n = 55) from 6 months before diagnosis to diagnosis, and -0.43 ng x ml(-1) x month(-1) (P = 0.002, n = 63) from the initial diabetic OGTT to the confirmatory diabetic OGTT.

CONCLUSIONS

It seems that postchallenge C-peptide levels begin to decrease appreciably in the 6 months before diagnosis and decrease even more rapidly within 3 months after diagnosis.

Clinical manifestations and beta cell function in Swedish diabetic children have remained unchanged during the last 25 years

BACKGROUND

The incidence of type 1 diabetes in childhood has doubled in Sweden during the last decades. Environmental factors may cause a different disease process, residual beta cell function and clinical manifestation. Insulin therapy has become more intensive. The aim of this study was to examine the clinical characteristics at onset, C-peptide secretion during the first years after diagnosis and if there was any secular trends during the last 25 years.

METHODS

All 316 children diagnosed with type 1 diabetes during 1976--2000 and living in the Linköping area were included. Information about clinical characteristics at diagnosis, duration of partial remission, insulin therapy at diagnosis and during the first years was collected from medical records. C-peptide secretion (fasting and stimulated) was measured regularly during the first 5 years. For analysis, the population was divided in five cohorts according to the year of diagnosis.

RESULTS

The clinical characteristics at onset were unchanged as well as duration of partial remission. C-peptide secretion was highest after 3 months and then declined gradually. After 5 years 32.7% of the patients had measurable fasting C-peptide, but only 6.5% > 0.1 nmol/L. HbA1c and insulin doses were lower in patients with persistent fasting C-peptide secretion > 0.1 nmol/L. The cohort 1996--2000 had higher stimulated C-peptide secretion at diagnosis and at 3 months, after longer follow-up there was no difference.

CONCLUSION

The clinical characteristics at diagnosis, partial remission and duration of C-peptide secretion have remained largely unchanged for the last 25 years.

Immune intervention at diagnosis--should we treat children to preserve beta-cell function?

Type 1 diabetes (T1D) is characterized by loss of beta-cell function. If beta-cell function can be preserved, it will lead to improved metabolic balance with improved quality of life and fewer acute and late complications, and if residual insulin secretion improves well enough, then that could lead to complete remission and even cure of the disease. Several efforts to save residual beta-cell function have been made for more than three decades without success. Proof of principle has been possible, and it seems clear that immune suppression or immune modulation, in fact, can stop the destructive process and thereby preserve beta-cell function. However, the effect seen in adult patients with T1D have been minimal or absent in diabetic children who seem to have another or at least more aggressive disease process. Furthermore, the immune interventions have had too serious and common adverse events in comparison to the scarce-positive effect. Recent more specific immune modulation with anti-CD3 monoclonal antibodies seems more encouraging with at least postponement of the C-peptide decline, but unfortunately still with common and quite threatening adverse effects. Even more promising are the autoantigen therapies, of which glutamic acid decarboxylase (GAD) vaccination has shown good results with impressive preservation of residual insulin secretion in 10- to 18-year-old type 1 diabetic patients with recent onset. In patients with short diabetes duration at intervention the effect was remarkable. Furthermore, these effects were achieved with no adverse events. Future studies will show whether the good effect seen so far can be confirmed. If so there is hope that GAD vaccination will cause remission and even cure and prevention of T1D will then no longer be just a dream.

'The honeymoon phase' in children with type 1 diabetes mellitus: frequency, duration, and influential factors

BACKGROUND

The honeymoon period (i.e., partial remission) of type 1 diabetes mellitus is characterized by reduced insulin requirements while good glycemic control is maintained. The clinical significance is the potential possibility for pharmacological intervention during this period to either slow down or arrest the ongoing destruction of the remaining beta-cells.

METHODS

A group of 103 diabetic children, younger than 12 yr of age, were prospectively studied to assess the frequency, duration, and factors that may affect partial remission. At the time of admission, patients were characterized by age, gender, symptom duration, diabetic ketoacidosis (DKA), and blood sugar level at admission. The honeymoon period was defined as a period with insulin requirements of less than 0.5 U/kg/day and hemoglobin A1c (HbA1c) level of less or equal to 6%.

RESULTS

Partial remission occurred in 71, being complete in three. The length of time until remission was 28.6 +/- 12.3 (mean +/- SD) days. The duration of remission was 7.2 +/- 4.8 months. Remission rates were higher in those patients older than 5 yr compared with those between 3 and 5 yr of age. DKA at presentation and long duration of symptoms were associated with lower duration of remission (p < 0.001 and p < 0.001, respectively). Children in whom remission occurred had significantly lower blood glucose levels and higher pH at presentation (p < 0.001 and p < 0.001, respectively).

CONCLUSIONS

Young age and severe disease at presentation are associated with decreased residual beta-cells function that is reflected by a lower incidence of partial remission. These observations are important to consider in the research regarding therapies that will have the potential goal to induce prolonged and/or complete remission at disease onset or shortly thereafter.

The rise and fall of insulin secretion in type 1 diabetes mellitus

An understanding of the natural history of beta cell responses is an essential prerequisite for interventional studies designed to prevent or treat type 1 diabetes. Here we review published data on changes in insulin responses in humans with type 1 diabetes. We also describe a new analysis of C-peptide responses in subjects who are at risk of type 1 diabetes and enrolled in the Diabetes Prevention Trial-1 (DPT-1). C-peptide responses to a mixed meal increase during childhood and through adolescence, but show no significant change during adult life; responses are lower in adults who progress to diabetes than in those who do not. The age-related increase in C-peptide responses may account for the higher levels of C-peptide observed in adults with newly diagnosed type 1 diabetes compared with those in children and adolescents. Based on these findings, we propose a revised model of the natural history of the disease, in which an age-related increase in functional beta cell responses before the onset of autoimmune beta cell damage is an important determinant of the clinical features of the disease.

Natural history of beta-cell function in type 1 diabetes

Despite extensive and ongoing investigations of the immune mechanisms of autoimmune diabetes in humans and animal models, there is much less information about the natural history of insulin secretion before and after the clinical presentation of type 1 diabetes and the factors that may affect its course. Studies of insulin production previously published and from the Diabetes Prevention Trial (DPT)-1 suggest that there is progressive impairment in insulin secretory responses but the reserve in response to physiological stimuli may be significant at the time of diagnosis, although maximal responses are more significantly impaired. Other factors, including insulin resistance, may play a role in the timing of clinical presentation along this continuum. The factors that predict the occurrence and rapidity of decline in beta-cell function are still largely unknown, but most studies have identified islet cell autoantibodies as predictors of future decline and age as a determinant of residual insulin production at diagnosis. Historical as well as recent clinical experience has emphasized the importance of residual insulin production for glycemic control and prevention of end-organ complications. Understanding the modifiers and predictors of beta-cell function would allow targeting immunological approaches to those individuals most likely to benefit from therapy.

C-peptide is the appropriate outcome measure for type 1 diabetes clinical trials to preserve beta-cell function: report of an ADA workshop, 21-22 October 2001

The underlying cause of type 1 diabetes, loss of beta-cell function, has become the therapeutic target for a number of interventions in patients with type 1 diabetes. Even though insulin therapies continue to improve, it remains difficult to achieve normal glycemic control in type 1 diabetes, especially long term. The associated risks of hypoglycemia and end-organ diabetic complications remain. Retention of beta-cell function in patients with type 1 diabetes is known to result in improved glycemic control and reduced hypoglycemia, retinopathy, and nephropathy. To facilitate the development of therapies aimed at altering the type 1 diabetes disease process, an American Diabetes Association workshop was convened to identify appropriate efficacy outcome measures in type 1 diabetes clinical trials. The following consensus emerged: While measurements of immune responses to islet cells are important in elucidating pathogenesis, none of these measures have directly correlated with the decline in endogenous insulin secretion. HbA(1c) is a highly valuable clinical measure of glycemic control, but it is an insensitive measure of beta-cell function, particularly with the currently accepted standard of near-normal glycemic control. Rates of severe hypoglycemia and diabetic complications ultimately will be improved by therapies that are effective at preserving beta-cell function but as primary outcomes require inordinately large and protracted trials. Endogenous insulin secretion is assessed best by measurement of C-peptide, which is cosecreted with insulin in a one-to-one molar ratio but unlike insulin experiences little first pass clearance by the liver. Measurement of C-peptide under standardized conditions provides a sensitive, well accepted, and clinically validated assessment of beta-cell function. C-peptide measurement is the most suitable primary outcome for clinical trials of therapies aimed at preserving or improving endogenous insulin secretion in type 1 diabetes patients. Available data demonstrate that even relatively modest treatment effects on C-peptide will result in clinically meaningful benefits. The development of therapies for addressing this important unmet clinical need will be facilitated by trials that are carefully designed with beta-cell function as determined by C-peptide measurement as the primary efficacy outcome.

Beta cell rest and recovery--does it bring patients with latent autoimmune diabetes in adults to euglycemia?

Diabetes mellitus in humans is a heterogeneous disorder classified clinically into two main types. The diagnosis of type 1 versus type 2 diabetes is made phenotypically using criteria such as age at onset, abruptness of hyperglycemic symptoms, presence of ketosis, degree of obesity and the perceived need for insulin replacement. The pathogeneses of type 1 and type 2 diabetes are believed to be different. Type 1 diabetes is an autoimmune disease mediated by cellular effector mechanisms; whereas classic type 2 diabetes is not autoimmune but results from insulin resistance and a nonautoimmune insulin secretory defect. Most type 1 diabetes patients are diagnosed in childhood or young adulthood before the age of 35 years. However, there is clearly a subgroup of patients clinically diagnosed with type 2 diabetes who are greater than 35 years of age and have evidence of autoimmunity. The disease of these autoantibody-positive type 2 diabetics is often termed latent autoimmune diabetes in adults (LADA), slowly progressive type 1 diabetes, latent type 1 diabetes, and type 1.5 diabetes. This group of patients comprises approximately 10-15% of Caucasian type 2 diabetes patients. Type 1.5 diabetes patients tend to present with islet cell autoantibodies, islet-reactive T cells, higher HbA(1c) levels, lower C peptide, and a propensity toward insulin dependency compared to autoantibody-negative classic type 2 diabetes subjects.

Severity at onset of childhood type 1 diabetes in countries with high and low incidence of the condition

Severity of Type 1 diabetes mellitus (DM) at presentation was compared between south-east Sweden and Lithuania where incidence of childhood Type 1 diabetes is three times lower than in Sweden. New cases of diabetes at age 0-15 years from August 1995 to March 1999 in south-east Sweden and from August 1996 to August 2000 in Lithuania were included. Symptoms and clinical characteristics at diagnosis were recorded. Data about the close environment were collected using questionnaires. Lithuanian children were diagnosed in a more severe condition, mean pH 7.30 and HbA(1c) 11.5% compared with mean pH 7.36 and HbA(1c) 9.7% in Swedish children (P<0.0001). More Lithuanian than Swedish children were diagnosed in ketoacidosis (pH < or = 7.2, hyperglycaemia and ketonuria), 21.3 versus 7.3% (P<0.0001). Only 4.6% of Swedish children and 1.0% of Lithuanian children had no symptoms (P=0.007). Children in families with at least one first degree relative with diabetes (12.2% in Sweden and 8.4% in Lithuania, NS) had laboratory values at diagnosis closer to normal than sporadic cases in either country. Factors predicting ketoacidosis in Sweden were an unemployed mother and absence of infections in the 6 months before diagnosis. In Lithuania it was younger age and mother with less education. Additional educational activities for doctors are needed in countries with low incidence to reduce prevalence of ketoacidosis at onset.

Treatment with antioxidants at onset of type 1 diabetes in children: a randomized, double-blind placebo-controlled study

BACKGROUND

In recent years different types of immune interventions have been tried at the onset of type 1 diabetes. Although some have shown effects, none have proven to be sufficiently effective to justify the inherent risks and side effects. Antioxidants have no or minimal side effects. If they can protect the beta cells against free oxygen radicals during the inflammatory process this would be a safe and cheap intervention. To evaluate this hypothesis a combination of various antioxidative agents was employed in a double-blind randomized study.

METHODS

The study group comprised 46 children aged 1-17 years at diagnosis. They were followed for 3 years: 2 years whilst taking the tablets and 1 year of follow-up. Twenty-four children were randomly allocated to active treatment with high doses of antioxidants and 22 children to placebo tablets. The tablets were the same size and tasted identical.

RESULTS

Twenty patients had for more than 1 month an insulin dose <0.5 U/kg in parallel with a normal HbA(1c) value and stable blood glucose values, but with no difference observed between those with and without active treatment. Nor was any significant difference observed regarding C-peptide values, fasting as well as stimulated. Whilst the antioxidants demonstrated no positive effect, they also had no negative side effects.

CONCLUSION

At diagnosis of type 1 diabetes in children, high doses of antioxidative agents have no effect either on the preservation of beta cell function or on metabolic balance.

Type 1 Diabetes

Type 1 (insulin-dependent) diabetes occurs worldwide and can appear at any age. The genetic susceptibility is strongly associated with HLA-DQ and DR on chromosome 6, but genetic factors on other chromosomes such as the insulin gene on chromosome 11 and the cytotoxic T-lymphocyte antigen gene on chromosome 2 may modulate disease risk. Numerous studies further support the view that environmental factors are important. Gestational infections may contribute to initiation, whereas later infections may accelerate islet β-cell autoimmunity. The pathogenesis is strongly related to autoimmunity against the islet β cells. Markers of autoimmunity include autoantibodies against glutamic acid decarboxylase, insulin, and islet cell antigen-2, a tyrosine phosphatase-like protein. Molecular techniques are used to establish reproducible and precise autoantibody assays, which have been subject to worldwide standardization. The diagnostic sensitivity (40–80%) and specificity (99%) of all three autoantibodies for type 1 diabetes are high, and double or triple positivity among first-degree relatives predicts disease. Combined genetic and antibody testing improved prediction in the general population despite the transient nature of these autoantibodies. Classification of diabetes has also been improved by autoantibody testing and may be used in type 2 diabetes to predict secondary failure and insulin requirement. Islet autoantibodies do not seem to be related to late complications but rather to metabolic control, perhaps because the presence of islet cell autoantibodies marks different residual β-cell function. Combined genetic and autoantibody screening permit rational approaches to identify subjects for secondary and tertiary intervention trials.

Prevention of type 1 diabetes

This article discusses type 1 diabetes mellitus, which results from insulin deficiency caused by autoimmune destruction of the insulin-producing beta-cells in the pancreatic islets of Langerhans. The autoimmune response against islet beta-cells is believed to result from a disorder of immunoregulation. According to this concept, T lymphocytes (T cells) autoreactive to certain beta-cell constituents exist normally but are restrained by regulatory (suppressor) T cells. Activation of beta-cell autoreactive T cells together with deficient regulatory T cell responses is believed to result in clonal expansion of autoreactive T cells, and these cells may elicit a cascade of beta-antigen specific (T cell) immune and nonspecific inflammatory responses that destroy islet beta-cells. Islet beta-cells autoreactive T cells seem to secrete type 1 cytokines, whereas regulatory T cells may secrete type 2 and type 3 cytokines; therefore, type 1 diabetes may result from a relative dominance of type 1 cytokines over type 2 and type 3 cytokines. These concepts derive mainly from studies in animal models with spontaneous autoimmune diabetes, and the evidence in humans with type 1 diabetes is sparse. Nevertheless, the concept of type 1 diabetes as a disorder of immunoregulation has spurred clinical trials of diabetes prevention based on strategies directed at diverting the immune response from autoimmunity to self-tolerance, for example, by administration of beta-cell autoantigens, and by attempting to tip the immune balance in favor of the production or action of type 2 and type 3 cytokines over type 1 cytokines.

Beta-cell rest: a strategy for the prevention of autoimmune diabetes

An autoantigen being recognized by specific receptors is the key reaction of an autoimmune disease. Whereas much efforts have been made to develop immunosuppressive regimens which reduce the amount of effector cells, and/or inhibit receptor activation, surprisingly little attention has been paid to reduce the ligand-receptor interaction by interfering with the amount of antigen being presented from the target cells. In this review, we discuss clinical observations in autoimmune endocrine disease which illustrate that target cell alterations can modify the disease activity and comment on recent clinical trials which indicate that beta-cell rest may be beneficial to the course of human autoimmune diabetes mellitus.

How to apply the experience from the diabetes control and complications trial to children and adolescents?

The Diabetes Control and Complications Trial (DCCT) taught us to set target blood glucose (BG) and glycohaemoglobin (GHb) goals, to ensure safety regarding hypoglycaemia, to be flexible with insulin and meal planning and to offer frequent contact with diabetes educators, dieticians, psychologists and social workers as well as with diabetologists skilled in intensified management. Insulin dosage should be individualized based upon frequent BG monitoring results. Co-ordinated multidisciplinary health care teams provide optimum problem-solving rather than disaster control working with children, adolescents and their families. The patient and the family should form the central core of the diabetes team with outpatient follow-up every month and frequent telephone contact between visits. GHb should be obtained at least every 1-2 months to provide feedback as based on the DCCT intensified treatment cohort. Insulin lispro helps minimize hypoglycaemia and makes insulin administration more convenient and timely. Barriers to improvement should be identified: learning problems, concomitant significant illnesses (epilepsy, coeliac and thyroid disease, asthma) and family problems. Ensure age-appropriate transfer of self-care but continue adult supervision. Educate, motivate and re-educate. Meal planning includes not only carbohydrate counting but also maintaining normal lipids and energy needs for growth and development as well as strategies for activity compensation and hypoglycaemia prevention. Consideration of protein restriction may be required in adolescents with microalbuminuria. Individualized multidose insulin algorithms allow reactive (corrective) decisions based upon capillary BG results plus proactive (anticipatory) decisions to compensate for expected BG changes from changes in activity, food and/or illness using a multidose insulin schedule. The number of insulin injections does not define an intensified insulin treatment programme but rather the ability to target and achieve near-normal BG values as often as possible - without severe episodes of hypoglycaemia. Self BG monitoring is a key to success. Long-term monitoring should include not only frequent GHb but also at least annual fasting lipids, thyroid functions and microalbuminuria as well as dilated retinal exams, blood pressure, growth charting and Tanner staging.

Autoantibodies in relation to residual insulin secretion in children with IDDM

To elucidate whether autoantibodies can be used to predict the intensity of autoimmune beta-cell destruction, we determined both C-peptide and autoantibodies (islet cell antibodies (ICA), insulin autoantibodies (IAA), islet cell surface antibodies (ICSA) and antibodies to glutamic acid decarboxylase (GADA)). In 89 diabetic children and adolescents at diagnosis at the age of 1.2-16.6 years (mean +/- S.D., 9.0 +/- 4.5). Only 12/89 (14%) had no autoantibodies at diagnosis, while 2 patients (2%) had all 4 autoantibodies. There was a positive correlation between GADA and ICA (P < 0.01). At diagnosis 70% of the patients had GADA, most common in patients above the age of 8 years at diagnosis (P < 0.001), and with higher GAD-index in girls (P < 0.05). ICA was detected in 63%, most common in the older age groups (P = 0.04). ICSA seen in 22% of the patients as well as IAA (detected in 32%) were most common < 8 years of age (P = 0.06, P = 0.08, respectively). Children with autoantibodies had similar C-peptide levels through the follow up period as children of the same sex and age without antibodies, except for patients with ICSA alone or in combination with other autoantibodies who tended to have higher C-peptide levels. We conclude that not even combinations of autoantibodies can be used to predict beta-cell destruction in IDDM patients.

Ketoacidosis at the diagnosis of type 1 (insulin dependent) diabetes mellitus is related to poor residual beta cell function. Childhood Diabetes in Finland Study Group

The determinants of the degree of metabolic decompensation at the diagnosis of type 1 (insulin dependent) diabetes mellitus (IDDM) and the possible role of diabetic ketoacidosis in the preservation and recovery of residual beta cell function were examined in 745 Finnish children and adolescents. Children younger than 2 years or older than 10 years of age were found to be more susceptible to diabetic ketoacidosis than children between 2 and 10 years of age (< 2 years: 53.3%; 2-10 years: 16.9%; > 10 years: 33.3%). Children from families with poor parental educational level had ketoacidosis more often than those from families with high parental educational level (24.4% v 16.9%). A serum C peptide concentration of 0.10 nmol/l or more was associated with a favourable metabolic situation. Low serum C peptide concentrations, high requirement of exogenous insulin, low prevalence of remission, and high glycated haemoglobin concentrations were observed during the follow up in the group of probands having diabetic ketoacidosis at the diagnosis of IDDM. Thus diabetic ketoacidosis at diagnosis is related to a decreased capacity for beta cell recovery after the clinical manifestation of IDDM in children.

An 8-year follow-up of anti-insulin antibodies in diabetic children: relation to insulin autoantibodies, HLA type, beta-cell function, clinical course and type of insulin therapy

In 105 children and adolescents with IDDM, insulin antibodies were detected as a percentage of radiolabelled insulin both at onset of disease and during the first 8 years of treatment. At diagnosis, 29 patients (27%) were insulin autoantibody positive (IAA+). An inverse relationship was found between IAA levels and age at diagnosis. No significant correlation was seen between IAA positivity and HLA antigens, while there was a negative correlation between IAA and C-peptide levels in the second year of the disease. The percentage of insulin antibody (IA) positive patients increased after insulin administration, with a maximum peak between the first and second year of the disease. The IA response to insulin therapy was similar in IAA+ and IAA- patients, while it was greater in younger children. No relationship was found between IA levels and haemoglobin A1c values, daily insulin requirement, HLA and early complications. No difference in either percentage of positivity or IA levels was seen in patients treated continually for the first 5 years of the disease with monocomponent porcine insulin or human insulin. A negative correlation was found between IA and C-peptide levels in the first and second years of the disease. In conclusion, we have shown that, even after many years of disease, neither IAA nor IA, induced in equal measures by current human insulin preparations, have significant effects on the clinical course of the disease.

Natural course of insulin sensitivity and insulin reserve in early insulin-dependent diabetes mellitus

Preservation of endogenous insulin in insulin-dependent diabetes mellitus (IDDM) may prevent the occurrence of diabetes-related complications. Therefore, it is important to known about insulin reserve and insulin sensitivity at clinical manifestation. Twenty-four patients (aged 23 +/- 6 years) were evaluated for 2 years starting at the day of clinical manifestation. Insulin secretion was stimulated by glucagon, arginine, and glucose on separate days. Insulin sensitivity was evaluated by hyperinsulinemic-euglycemic clamp. Two control groups were established, one consisting of age-, weight-, and sex-matched healthy individuals, the other of patients with diabetes of long duration (6 to 13 years). Sensitivity improved from 30% of normal at baseline to 84% after only 2 weeks in the newly manifested patients. Subsequently, insulin released by nonglucose stimuli increased by 75%. Glucose-induced first-phase insulin secretion did not recover. After 2 years, sensitivity was 20% less than normal and glucagon-stimulated C-peptide (GSCP) was 0.64 +/- 0.20 nmol/L (0.41 +/- 0.19 at baseline, P < .002). Insulin sensitivities in euglycemic and hyperglycemic conditions were closely correlated. In conclusion, improvement of insulin sensitivity precedes and is possibly a prerequisite for the recovery of residual insulin in early IDDM.

Glycosylated hemoglobin in fractions of erythrocytes of different ages

In 65 children and adolescents with type I diabetes and in 23 healthy controls, glycosylated hemoglobin (HbA1) was measured by ion exchange chromatography in a specimen of whole blood and in three fractions of erythrocytes of different ages. The red blood cells were separated in a density-gradient medium. Three layers were obtained. The top one consisted of younger and lighter cells, while the heaviest and oldest cells were found in the bottom layer. The separation was evaluated by measuring the potassium concentration, which was significantly different in each fraction (p < 0.001). In all healthy controls the lowest HbA1 value was measured in the youngest and the highest in the oldest erythrocytes. In the diabetic patients, however, the HbA1 levels in individual red cell fractions depended on the degree of metabolic control during the life span of the cells. Significant correlation was found between the HbA1 levels in the youngest erythrocytes and metabolic control in the two-week period before investigation (p < 0.001), between the HbA1 content of the medium-aged cell fraction and control two months before assay (p < 0.001), and between HbA1 levels in the oldest erythrocytes and control three and especially four months prior to investigation (p < 0.001). The results of HbA1 determination in the fraction of the youngest cells which show the highest correlation (-0.75) with the glucosuria two weeks prior to assay indicate to be one of possibilities to get information about metabolic control in that period.

Immunoprotection in spontaneous remission of type 1 diabetes: long-term follow-up results

This prospective pilot study was undertaken to test the efficacy of oral methyl-prednisolone (MP) therapy at spontaneous remission phase of type 1 diabetes in intervening the course of the disease. Twenty-five type 1 diabetic patients who were classified as having a spontaneous remission (honeymoon) were divided into treatment and non-treatment groups on voluntary basis. Fifteen patients thus making up the treatment group (13 males and 2 females, mean age 23.8 +/- 6.2 years) received 0.7-1.0 mg/kg/day of MP p.o. for 2 weeks. The dose of the drug was then gradually diminished every week until 5 mg/day (approx. 0.1 mg/kg/day) and discontinued at 10 +/- 2 weeks. In case of hyperglycemia occurring in 12 of 15 patients due to the administration of steroid, insulin was used to normalize blood glucose levels (average 0.47 +/- 0.21 IU/kg/day). The non-treatment group (8 males and 2 females, mean age 21.8 +/- 8.9) did not receive any special medication or placebo except for insulin whenever necessary to regulate glycemia. Upon completion of protocol, all patients in treatment group displayed clinical remission with 10 still in non-insulin requiring remission for follow-up periods ranging between 16 and 91 months. The remaining 5 patients relapsed within 3-15 months of therapy. Other metabolic (including basal and stimulated C-peptide levels) and immunological indices that have spontaneously ameliorated with the occurrence of honeymoon were also maintained within normal range in the NIR patients. Meanwhile, natural remission in the non-MP-treated group terminated at 3.4 +/- 0.6 months with deterioration of all metabolic and immunological markers as well as increasing requirements for insulin. In conclusion, the spontaneous remission of the patients could be prolonged significantly by MP therapy as opposed to no therapy (P < 0.001). These results suggest that the spontaneous remission phase may be a crucial point of intervention in immunotherapy of type 1 diabetes and that randomized trials with MP at this particular phase would be worthwhile.

Clinical and laboratory features of type 1 diabetic children at the time of diagnosis

The French incidence study has registered all new cases of Type 1 diabetic children under 20 years of age, from a population of 2.32 million, in an exhaustive and prospective manner. Three hundred and forty cases were identified between 1 January 1988 and 31 December 1989, yielding a mean annual incidence rate 7.3 per 10(5). The lowest rate was observed in the youngest age group (0-4 yr: 4.1 per 10(5)) and the highest around pubertal development (10-14 yr: 11.5 per 10(5)). Details of the previous personal and family history, and the clinical and biological pictures of the disease at diagnosis were recorded. Almost 8 per cent of the children had a first-degree relative with Type 1 diabetes. Polyuria, weight loss, fatigue and abdominal pain were the most frequently reported symptoms, which were of median duration 4.4 months. Mean weight loss before diagnosis was 9.4 +/- 6.8 (+/- SD)% of body weight and was not significantly related to age. Ketonuria was detected in 83.8 per cent and acidosis (total CO2 less than or equal to 18 mmol l-1, if measured) in 48 per cent of the cases. Ketonuria and acidosis were significantly more frequent in the younger age group than in the rest of the group (p less than 0.001).

Cyclosporine in recent onset type I diabetes mellitus. Effects on islet beta cell function. Miami Cyclosporine Diabetes Study Group

To confirm the immunological basis of type I diabetes and to determine if immune intervention alters the course of the disease, we studied the use of cyclosporine in a 1-year randomized, double-masked, placebo-controlled trial in 23 subjects enrolled within 6 weeks of diagnosis. Subjects included 12 males and 11 females, ages 9-38 years (mean, 19.7 +/- 1.8 years). Initial dosage of cyclosporine was 10 mg/kg/day, given as a single daily dose, adjusted on the basis of side effects and trough cyclosporine levels. Glycemic control and insulin dosage were similar in both cyclosporine and placebo groups. The frequency of freedom from insulin usage also was similar in both groups; however, it is not possible to draw conclusions about response rates, because of the very small sample size. Glucose tolerance, as measured by rate of intravenous glucose disposal did not differ between groups. Islet beta cell function was measured by determining C-peptide response to three secretogogues: intravenous glucagon, intravenous glucose, and a mixed formula meal (Sustacal). There were no differences between groups in the C-peptide responses either to intravenous glucagon or intravenous glucose. Moreover, acute insulin response to intravenous glucose was not restored in any subject. On the other hand, in comparison to the placebo group, the cyclosporine group did show an increased meal-stimulated C-peptide response after 3, 6, 9, and 12 months. When measured by regression analysis, the slope defining the rate of decline of beta cell function was significantly slower for the cyclosporine group than the placebo group (p less than 0.05). Thus, as measured in response to a physiological stimulus (meal challenge), cyclosporine preserves islet beta cell function when used in recent onset type I diabetes. Side effects were minimal and reversible upon cessation of immune intervention. The preservation of islet beta cell function by immune intervention is consistent with the hypothesis that type I diabetes has an immune mechanism involved in its pathogenesis.

The functional state of the beta cells in the pathogenesis of insulin-dependent diabetes mellitus

Besides the thymus-dependent immune system, growing evidence suggests that the functional state of the beta cell plays a role in the pathogenesis of Type 1 (insulin-dependent) diabetes. Increased incidence of diabetes has been described after increased insulin production and vice versa, and actual hyperinsulinemia has been observed in relation to the diabetogenesis. Prophylactic insulin treatment and intensive insulin therapy at diagnosis are discussed. The studies referred to are mostly animal model investigations of BB rats and NOD mice and-to a lesser degree- of streptozotocin- and encephalomyocarditis-virus-induced diabetes. Also human evidence exists, but naturally of a more sporadic character. Three possible mechanisms behind the beta cell sensitivity as a function of their activity are suggested: increased antigen expression (including both gangliosides and proteins) in beta cells with high activity which could activate the destruction caused by the immune system, and increased susceptibility to the toxicity of interleukins and to diabetogenic agents. With respect to developing preventive treatment the described research area may turn out to be very important. Further studies both in animal models and in humans are awaited.

Factors predicting residual beta-cell function in the first year after diagnosis of childhood type 1 diabetes

Twenty-five children aged 2-14 years (mean age 8.39 +/- 0.78 years) were studied prospectively during the first year after the diagnosis of type 1 diabetes. Of their clinical and metabolic features at diagnosis, only age showed a significant independent relationship with endogenous C-peptide production during the first year. Age was correlated with higher values for basal and stimulated plasma C-peptide at 7-14 days after diagnosis, at 6 months and at 12 months. At diagnosis, age was also associated with a higher value for HbA1c and a lower prevalence of insulin antibodies. C-peptide production peaked at 3 months and thereafter declined. Mean HbA1c and insulin requirement were both minimal at 6 months. At diagnosis, there were significant inverse relationships between basal C-peptide production and both insulin dose and HbA1c and between stimulated C-peptide production and HbA1c. Basal and stimulated C-peptide production were inversely related to insulin dose at 6 and 12 months. Stimulated C-peptide was higher at 12 months in children retaining islet cell antibodies. These findings confirm the importance of age as a predictor of residual beta-cell function in type 1 diabetes and indicate that older children present clinically following a slower course of beta cell destruction.

Prevalence of anti-insulin antibodies and its relation to severe hypoglycaemia in insulin-treated diabetic patients

The prevalence of anti-insulin antibodies (AIABs) and their association with clinical parameters, metabolic control and severe hypoglycaemia were investigated in a geographically defined population of insulin-treated diabetic patients. Eighty per cent of the patients (479) delivered venous blood samples and answered a questionnaire on severe hypoglycaemic problems during a 12-month period. Circulating AIABs were demonstrable in 78% of the patients, being more common among those with type 1 diabetes and in long-duration patients. High levels of AIABs were also more frequent in patients in whom insulin treatment had been initiated prior to the era of highly purified insulins. The AIABs did not correlate to metabolic control, insulin dose or severe hypoglycaemia. It is concluded that AIABs is not a risk factor for severe hypoglycaemia in insulin-treated diabetic patients.

Continuous subcutaneous insulin infusion (CSII) versus conventional injection therapy in newly diagnosed diabetic children: two-year follow-up of a randomized, prospective trial

The effect of continuous subcutaneous insulin infusion (CSII), begun at diagnosis, on blood glucose control and endogenous insulin production was studied in a group of consecutively referred newly diagnosed diabetic children. In a random order, 15 children started CSII (age 9.5 +/- 4.2 (+/- SD) years) and 15 conventional injection therapy (age 7.0 +/- 3.6 years). For 2 years HbA1 and urinary C-peptide were measured monthly, C-peptide responses to glucagon 6-monthly, and insulin antibodies every 3 months. None of the patients requested change of therapy during the study period, but at 28 months 1 adolescent girl changed to injection therapy from CSII. Severe hypoglycaemia was observed once in each group, but ketoacidosis only once, in the injection therapy group. From 2 months after diagnosis onwards the CSII group had significantly lower HbA1 levels. Urinary and plasma C-peptide levels did not differ between the two groups and similar insulin doses were used throughout the study. At the end of the 2 years of therapy, the CSII group had significantly lower insulin antibody levels. The observations suggest that CSII is well accepted in newly diagnosed children and improves metabolic control, but does not prolong endogenous insulin production.

Immunological aspects on IDDM in children

Diabetes mellitus in childhood is connected to several immunological phenomena which per se do not prove that immunological mechanisms do cause the beta cell destruction, as such mechanisms could be just secondary. However, there is now evidence which strongly supports the autoimmune hypothesis, like the beta-cell destruction in the transplant given from a healthy twin to the diabetic monozygotic co-twin, the effect in newly-diagnosed diabetes of immunosuppression, the passive transfer in experimental animals of an immune process creating diabetes etc. Several facts such as presence of activated T-cells in the insulitis indicate that the cell-mediated immunity is important, while it is still debatable whether humoral factors, and if so which, alone could be responsible for the beta cell destruction. Recently interleukins and other lymphokines have shown to be of great interest as well as the release of free radicals. This knowledge opens new views on the possibility to put an end to or even prevent the beta cell destruction. Rough immunosuppression with cytostatics or cyclosporin has such severe side-effects that such therapy is contra-indicated at least in children. Until more specific therapies are discovered e.g. vaccination with lymphoblasts or blocking the autoantigens with monoclonal antibodies, supportive measures to protect the beta cells may be one practical way.

Clinical significance of urinary C-peptide excretion in children with insulin-dependent diabetes mellitus

In order to evaluate the accuracy of urinary C-peptide determination and the clinical significance of C-peptiduria for the early course of insulin-dependent diabetes (IDDM), the rate of urinary excretion of C-peptide was determined in 32 children and adolescents with IDDM and correlated with serum C-peptide concentration, urinary excretion of albumin and beta 2-microgloublin and with the glomerular filtration rate (GFR) measured in terms of the clearance of 99mTc-DTPA. The age of the subjects ranged from 9.1 to 17.1 years (mean 13.1) and the duration of diabetes from 0.3 to 11.9 years (mean 4.6). There was a good correlation between postprandial serum C-peptide concentration and the 24-hour urinary C-peptide excretion rate (r = 0.81; p less than 0.001). GFR and urinary albumin excretion were slightly elevated in the diabetic patients as compared with non-diabetic subjects (p less than 0.05 and p less than 0.001, respectively), but C-peptide excretion was unrelated to the degree of hyperfiltration or albuminuria, neither was there any correlation between the excretion rate of beta 2-microglobulin and C-peptide. Glycaemic control was poorer in the diabetic children who had only trace amounts of C-peptide in their urine (less than 0.05 nmol/m2/24 h) than in those with minimal (0.05-1.0 nmol/m2) or moderate 24-hour urinary C-peptide excretion (greater than 1.0 nmol/m2). It is concluded that urinary C-peptide excretion serves very well to reflect residual beta-cell function and is unrelated to the slight renal hyperfunction and albuminuria often seen in diabetic subjects.(ABSTRACT TRUNCATED AT 250 WORDS)