Residual β-cell function after 10 years of autoimmune type 1 diabetes: prevalence, possible determinants, and implications for metabolism

Preserved C-peptide is common and associated with higher time in range in Chinese type 1 diabetes

Objective

The aim of this study is to determine the residual C-peptide level and to explore the clinical significance of preserved C-peptide secretion in glycemic control in Chinese individuals with type 1 diabetes (T1D).

Research design and methods

A total of 534 participants with T1D were enrolled and divided into two groups, low-C-peptide group (fasting C-peptide ≤10 pmol/L) and preserved-C-peptide group (fasting C-peptide >10 pmol/L), and clinical factors were compared between the two groups. In 174 participants who were followed, factors associated with C-peptide loss were also identified by Cox regression. In addition, glucose metrics derived from intermittently scanned continuous glucose monitoring were compared between individuals with low C-peptide and those with preserved C-peptide in 178 participants.

Results

The lack of preserved C-peptide was associated with longer diabetes duration, glutamic acid decarboxylase autoantibody, and higher daily insulin doses, after adjustment {OR, 1.10 [interquartile range (IQR), 1.06-1.14]; OR, 0.46 (IQR, 0.27-0.77); OR, 1.04 (IQR, 1.02-1.06)}. In the longitudinal analysis, the percentages of individuals with preserved C-peptide were 71.4%, 56.8%, 71.7%, 62.5%, and 22.2% over 5 years of follow-up. Preserved C-peptide was also associated with higher time in range after adjustment of diabetes duration [62.4 (IQR, 47.3-76.6) vs. 50.3 (IQR, 36.2-63.0) %, adjusted P = 0.003].

Conclusions

Our results indicate that a high proportion of Chinese patients with T1D had preserved C-peptide secretion. Meanwhile, residual C-peptide was associated with favorable glycemic control, suggesting the importance of research on adjunctive therapy to maintain β-cell function in T1D.

Changes in C-Peptide Values in Children with Type 1 Diabetes - a Three-Year Study

Background: C-peptide is used as an important indicator of residual insulin secretion in patients diagnosed with type 1 diabetes mellitus (T1DM) and treated with insulin. Aim:We have aimed to monitor the serum C-peptide (CP) levels during the first three years after diagnosis of T1DM in a cohort of children admitted to the Diabetes Department of "M. S. Curie" Emergency Clinical Hospital for Children, Bucharest, Romania, and to investigate the factors that could influence the rate of decline in its secretion. Method:We conducted a longitudinal, retrospective cohort study on a group of 215 children and adolescents who met the inclusion criteria and were monitored in our clinic over the course of a long period of time. We analyzed several parameters, including fasting serum CP values at diagnosis and yearly throughout T1DM evolution, the severity of diabetic ketoacidosis (DKA) at onset, HbA1c at diagnosis, family history of T1DM/T2DM, patient gender and presence of concurrent acute infectious disease at diagnosis, with the purpose of evaluating their influence on the preservation of endogenous insulin secretion. Based on serum CP value measured three years after T1DM onset, patients were divided into two groups: group 1, with low insulin residual secretion (CP < 0.6 ng/mL), and group 2, with preserved insulin residual secretion (CP ≥0.6 ng/mL) Results:At the moment of diagnosis, patients in group 1 were younger than those in group 2 (6.03 ± 3.54 years and 9.76 ± 2.75 years, respectively). The proportion of children with diabetic ketoacidosis (DKA) at onset was greater in group 1 (68% of patients) than group 2, in which the majority of subjects (60%) did not have DKA. The C-peptide value at diagnosis was significantly lower (0.55 ± 0.36 ng/mL) among patients in group 1 than those in group 2 (1.11 ± 0.59 ng/mL). In group 1 there was a higher proportion of patients (65%) with acute infectious disease at onset. Family history of T1DM/T2DM was associated with a more rapid decline in CP values. Our data showed no correlation between CP levels monitored for three years and HbA1c at diagnosis and no association with the gender of each patient. Conclusion:Patients with higher CP concentrations at diagnosis maintained increased values (> 0.6 ng/mL) three years after disease onset. Younger children had a faster decline of CP secretion during the first three years following diabetes diagnosis. In patients with severe symptoms (DKA) and associated infectious disease at onset, a risk of rapid CP decline was found.

Residual β-cell function in Brazilian Type 1 diabetes after 3 years of diagnosis: prevalence and association with low presence of nephropathy

BACKGROUND

Persistence of β cell-function in Type 1 diabetes (T1D) is associated with glycaemia stability and lower prevalence of microvascular complications. We aimed to assess the prevalence of residual C- peptide secretion in long-term Brazilian childhood onset T1D receiving usual diabetes care and its association to clinical, metabolic variables and microvascular complications.

METHODS

A cross-sectional observational study with 138 T1D adults with ≥ 3 years from the diagnosis by routine diabetes care. Clinical, metabolic variables and microvascular complications were compared between positive ultra-sensitive fasting serum C-peptide (FCP +) and negative (FCP-) participants.

RESULTS

T1D studied had ≥ 3 yrs. of diagnosis and 60% had FCP > 1.15 pmol/L. FCP + T1D were older at diagnosis (10 vs 8 y.o; p = 0.03) and had less duration of diabetes (11 vs 15 y.o; p = 0.002). There was no association between the FCP + and other clinical and metabolic variable but there was inversely association with microalbuminuria (28.6% vs 13.4%, p = 0.03), regardless of HbA_1c. FCP > 47 pmol/L were associated with nephropathy protection but were not related to others microvascular complications.

CONCLUSION

Residual insulin secretion is present in 60% of T1D with ≥ 3 years of diagnosis in routine diabetes care. FCP + was positively associated with age of diagnosis and negatively with duration of disease and microalbuminuria, regardless of HbA_1c.

Estimating the total incidence of type 1 diabetes in children and adolescents aged 0-19 years from 1990 to 2050: a global simulation-based analysis

BACKGROUND

Previous studies of type 1 diabetes in childhood and adolescence have found large variations in reported incidence around the world. However, it is unclear whether these reported incidence levels are impacted by differences in country health systems and possible underdiagnosis and if so, to what degree. The aim of this study was to estimate both the total and diagnosed incidence of type 1 diabetes globally and to project childhood type 1 diabetes incidence indicators from 1990 to 2050 for each country.

METHODS

We developed the type 1 diabetes global microsimulation model to simulate the natural history and diagnosis of type 1 diabetes for children and adolescents (aged 0-19 years) in 200 countries and territories, accounting for variability in underlying incidence and health system performance. The model follows an open population of children and adolescents in monthly intervals and simulates type 1 diabetes incidence and progression, as well as health system factors which influence diagnosis. We calibrated the model to published data on type 1 diabetes incidence, autoantibody profiles, and proportion of cases diagnosed with diabetic ketoacidosis from 1990 to 2020 and assessed the predictive accuracy using a randomly sampled test set of data withheld from calibration.

FINDINGS

We estimate that in 2021 there were 355 900 (95% UI 334 200-377 300) total new cases of type 1 diabetes globally among children and adolescents, of which 56% (200 400 cases, 95% UI 180 600-219 500) were diagnosed. Estimated underdiagnosis varies substantially by region, with over 95% of new cases diagnosed in Australia and New Zealand, western and northern Europe, and North America, but less than 35% of new cases diagnosed in west Africa, south and southeastern Asia, and Melanesia. The total number of incident childhood cases of type 1 diabetes is projected to increase to 476 700 (95% UI 449 500-504 300) in 2050.

INTERPRETATION

Our research indicates that the total global incidence of childhood and adolescent type 1 diabetes is larger than previously estimated, with nearly one-in-two children currently undiagnosed. Policymakers should plan for adequate diagnostic and medical capacity to improve timely type 1 diabetes detection and treatment, particularly as incidence is projected to increase worldwide, with highest numbers of new cases in Africa.

FUNDING

Novo Nordisk.

Gut microbiome and metabolic activity in type 1 diabetes: An analysis based on the presence of GADA

OBJECTIVE

Type 1 diabetes (T1D) progression is affected by circulating glutamic acid decarboxylase antibody (GADA) that persist for many years. This study aimed at investigating whether and how the gut microbiome and its correlated metabolites change in T1D with the presence of GADA.

METHODS

We used a radiobinding assay to measure GADA titers and identify the 49 T1D patients with GADA+ and 52 T1D patients with GADA-. The fresh feces and serum were analyzed using 16S rRNA gene sequencing and GC/MS. Then gut microbiome and serum metabolites were compared between the GADA+ patients and the GADA- patients. The association between gut microbial community and metabolites was assessed using the Spearman's rank correlation.

RESULTS

The gut microbiome in diversity, composition, and function differed between these two groups. The abundance of genus Alistipes, Ruminococcus significantly increased in patients with GADA+ compared to that observed in the samples of GADA-. There were 54 significantly altered serum metabolites associated with tryptophan metabolism, phenylalanine, and tyrosine biosynthesis in individuals with GADA+ compared with those of GADA-For the serum metabolites, compared with those of GADA-, there were 54 significantly different metabolites with tryptophan metabolism, phenylalanine, and tyrosine and tryptophan biosynthesis decreased in individuals with GADA+. The abundance of Alistipes was positively correlated with altered metabolites involved in tryptophan metabolism.

CONCLUSION

We demonstrate that T1D patients with GADA+ are characterised by aberrant profiles of gut microbiota and serum metabolites. The abundance of Alistipes disturbances may participate in the development of T1D patients with GADA by modulating the host's tryptophan metabolism. These findings extend our insights into the association between the gut microbiota and tryptophan metabolism and GADA and might be targeted for preventing the development of T1D.