Cohort profile: the 'Biomarkers of heterogeneity in type 1 diabetes' study-a national prospective cohort study of clinical and metabolic phenotyping of individuals with long-standing type 1 diabetes in the Netherlands.

PURPOSE: The 'Biomarkers of heterogeneity in type 1 diabetes' study cohort was set up to identify genetic, physiological and psychosocial factors explaining the observed heterogeneity in disease progression and the development of complications in people with long-standing type 1 diabetes (T1D). PARTICIPANTS: Data and samples were collected in two subsets. A prospective cohort of 611 participants aged ≥16 years with ≥5 years T1D duration from four Dutch Diabetes clinics between 2016 and 2021 (median age 32 years; median diabetes duration 12 years; 59% female; mean glycated haemoglobin (HbA1c) 61 mmol/mol (7.7%); 61% on insulin pump; 23% on continuous glucose monitoring (CGM)). Physical assessments were performed, blood and urine samples were collected, and participants completed questionnaires. A subgroup of participants underwent mixed-meal tolerance tests (MMTTs) at baseline (n=169) and at 1-year follow-up (n=104). Genetic data and linkage to medical and administrative records were also available. A second cross-sectional cohort included participants with ≥35 years of T1D duration (currently n=160; median age 64 years; median diabetes duration 45 years; 45% female; mean HbA1c 58 mmol/mol (7.4%); 51% on insulin pump; 83% on CGM), recruited from five centres and measurements, samples and 5-year retrospective data were collected. FINDINGS TO DATE: Stimulated residual C-peptide was detectable in an additional 10% of individuals compared with fasting residual C-peptide secretion. MMTT measurements at 90 min and 120 min showed good concordance with the MMTT total area under the curve. An overall decrease of C-peptide at 1-year follow-up was observed. Fasting residual C-peptide secretion is associated with a decreased risk of impaired awareness of hypoglycaemia. FUTURE PLANS: Research groups are invited to consider the use of these data and the sample collection. Future work will include additional hormones, beta-cell-directed autoimmunity, specific immune markers, microRNAs, metabolomics and gene expression data, combined with glucometrics, anthropometric and clinical data, and additional markers of residual beta-cell function. TRIAL REGISTRATION NUMBER: NCT04977635.

Socio-economic disparities in hospital care among Dutch patients with diabetes mellitus.

AIM: Socio-economic status (SES) influences diabetes onset, progression and treatment. In this study, the associations between SES and use of hospital care were assessed, focusing on hospitalizations, technology and cardiovascular complications. MATERIALS AND METHODS: This was an observational cohort study comprising 196 695 patients with diabetes (all types and ages) treated in 65 hospitals across the Netherlands from 2019 to 2020 using reimbursement data. Patients were stratified in low, middle, or high SES based on residential areas derived from four-digit zip codes. RESULTS: Children and adults with low SES were hospitalized more often than patients with middle or high SES (children: 22%, 19% and 15%, respectively; p < .001, adults: 28%, 25% and 23%; p < .001). Patients with low SES used the least technology: no technology in 48% of children with low SES versus 40% with middle SES and 38% with high SES. In children, continuous subcutaneous insulin infusion (CSII) and real-time continuous glucose monitoring (rtCGM) use was higher in high SES {CSII: odds ratio (OR) 1.54 [95% confidence interval (CI) 1.35-1.76]; p < .001; rtCGM OR 1.39 [95% CI 1.20-1.61]; p < .001} and middle SES [CSII: OR 1.41 (95% CI 1.24-1.62); p < .001; rtCGM: OR 1.27 (95% CI 1.09-1.47); p = .002] compared with low SES. Macrovascular (OR 0.78 (95% CI 0.75-0.80); p < .001) and microvascular complications [OR 0.95 (95% CI 0.93-0.98); p < .001] occurred less in high than in low SES. CONCLUSIONS: Socio-economic disparities were observed in patients with diabetes treated in Dutch hospitals, where basic health care is covered. Patients with low SES were hospitalized more often, used less technology, and adults with high SES showed fewer cardiovascular complications. These inequities warrant attention to guarantee equal outcomes for all.

Does size matter? Hospital volume and resource use in paediatric diabetes care.

AIMS: Paediatric diabetes care has become increasingly specialised due to the multidisciplinary approach and technological developments. Guidelines recommend sufficient experience of treatment teams. This study evaluates associations between hospital volume and resource use and hospital expenditure in Dutch children with diabetes. METHODS: Retrospective cohort study using hospital claims data of 5082 children treated across 44 Dutch hospitals (2019-2020). Hospitals were categorised into three categories; small (≥20-100 patients), medium (≥100-200 patients) and large (≥200 patients). All-cause hospitalisations, consultations, technology and hospital expenditure were analysed and adjusted for age, sex, socio-economic status (SES) and hospital of treatment. RESULTS: Fewer hospitalisations were observed in large hospitals compared to small hospitals (OR 0.48; [95% CI 0.32-0.72]; p < 0.001). Median number of yearly paediatrician visits was 7 in large and 6 in small hospitals, the significance of which was attenuated in multilevel analysis (OR ≥7 consultations: 1.89; [95%CI 0.74-4.83]; p = 0.18). Technology use varies between individual hospitals, whereas pump usage and real-time continuous glucose monitoring showed no significant differences between hospital volumes. Mean overall expenditure was highest in medium-sized centres with €6434 per patient (IQR €2555-7955); the difference in diabetes care costs was not significant between hospital patient volumes. CONCLUSIONS: Care provision patterns vary by hospital patient volume. Large hospitals had the lowest hospitalisation rates. The use of diabetes technology was not different between hospital patient volumes. Medium-sized hospitals showed the highest overall expenditure, but diabetes care costs were similar across hospital volumes.

Potency of quality indicators in Dutch and international diabetes registries.

BACKGROUND: Diabetes mellitus forms a slow pandemic. Cardiovascular risk and quality of diabetes care are strongly associated. Quality indicators improve diabetes management and reduce mortality and costs. Various national diabetes registries render national quality indicators. We describe diabetes care indicators for Dutch children and adults with diabetes, and compare them with indicators established by registries worldwide. METHODS: Indicator scores were derived from the Dutch Pediatric and Adult Registry of Diabetes Indicator sets of other national diabetes registries were collected and juxtaposed with global and continental initiatives for indicator sets. RESULTS: This observational cohort study included 3738 patients representative of the Dutch diabetic outpatient population. The Dutch Pediatric and Adult Registry of Diabetes harbors ten quality indicators comprising treatment volumes, HbA1c control, foot examination, insulin pump therapy, and real-time continuous glucose monitoring. Worldwide, nine national registries record quality indicators, with great variety between registries. HbA1c control is recorded most frequently, and no indicator is reported among all registries. CONCLUSIONS: Wide variety among quality indicators recorded by national diabetes registries hinders international comparison and interpretation of quality of diabetes care. The potential of quality evaluation will be greatly enhanced when diabetes care indicators are aligned in an international standard set with variation across countries taken into consideration.

Differences in lipid and blood pressure measurements between individuals with type 1 diabetes and the general population: a cross-sectional study.

OBJECTIVES: Cardiovascular disease (CVD) is a precarious complication of type 1 diabetes (T1D). Alongside glycaemic control, lipid and blood pressure (BP) management are essential for the prevention of CVD. However, age-specific differences in lipid and BP between individuals with T1D and the general population are relatively unknown. DESIGN: Cross-sectional study. SETTING: Six diabetes outpatient clinics and individuals from the Lifelines cohort, a multigenerational cohort from the Northern Netherlands. PARTICIPANTS: 2178 adults with T1D and 146 22 individuals without diabetes from the general population. PRIMARY AND SECONDARY OUTCOME MEASURES: Total cholesterol, low-density lipoprotein cholesterol (LDL-cholesterol), systolic BP (SBP) and diastolic BP (DBP), stratified by age group, glycated haemoglobin category, medication use and sex. RESULTS: In total, 2178 individuals with T1D and 146 822 without diabetes were included in this study. Total cholesterol and LDL-cholesterol were lower and SBP and DBP were higher in individuals with T1D in comparison to the background population. When stratified by age and medication use, total cholesterol and LDL-cholesterol were lower and SBP and DBP were higher in the T1D population. Men with T1D achieved lower LDL-cholesterol levels both with and without medication in older age groups in comparison to women. Women with T1D had up to 8 mm Hg higher SBP compared with the background population, this difference was not present in men. CONCLUSIONS: Lipid and BP measurements are not comparable between individuals with T1D and the general population and are particularly unfavourable for BP in the T1D group. There are potential sex differences in the management of LDL-cholesterol and BP.

Diabetes care practices and outcomes in 40.000 children and adolescents with type 1 diabetes from the SWEET registry during the COVID-19 pandemic.

AIMS: This study aimed to provide a global insight into initiatives in type 1 diabetes care driven by the COVID-19 pandemic and associations with glycemic outcomes. METHODS: An online questionnaire regarding diabetes care before and during the pandemic was sent to all centers (n = 97, 66,985 youth with type 1 diabetes) active in the SWEET registry. Eighty-two responded, and 70 (42,798 youth with type 1 diabetes) had available data (from individuals with type 1 diabetes duration >3 months, aged ≤21 years) for all 4 years from 2018 to 2021. Statistical models were adjusted, among others, for technology use. RESULTS: Sixty-five centers provided telemedicine during COVID-19. Among those centers naive to telemedicine before the pandemic (n = 22), four continued only face-to-face visits. Centers that transitioned partially to telemedicine (n = 32) showed a steady increase in HbA1c between 2018 and 2021 (p < 0.001). Those that transitioned mainly to telemedicine (n = 33 %) improved HbA1c in 2021 compared to 2018 (p < 0.001). CONCLUSIONS: Changes to models of care delivery driven by the pandemic showed significant associations with HbA1c shortly after the pandemic outbreak and 2 years of follow-up. The association appeared independent of the concomitant increase in technology use among youth with type 1 diabetes.

Healthcare expenditure and technology use in pediatric diabetes care.

BACKGROUND: Diabetes mellitus is one of the most common chronic diseases in childhood. With more advanced care options including ever-evolving technology, allocation of resources becomes increasingly important to guarantee equal care for all. Therefore, we investigated healthcare resource utilization, hospital costs, and its determinants in Dutch children with diabetes. METHODS: We conducted a retrospective, observational analysis with hospital claims data of 5,474 children with diabetes mellitus treated in 64 hospitals across the Netherlands between 2019-2020. RESULTS: Total hospital costs were €33,002,652 per year, and most of these costs were diabetes-associated (€28,151,381; 85.3%). Mean annual diabetes costs were €5,143 per child, and treatment-related costs determined 61.8%. Diabetes technology significantly increased yearly diabetes costs compared to no technology: insulin pumps € 4,759 (28.7% of children), Real-Time Continuous Glucose Monitoring € 7,259 (2.1% of children), and the combination of these treatment modalities € 9,579 (27.3% of children). Technology use increased treatment costs significantly (5.9 - 15.3 times), but lower all-cause hospitalisation rates were observed. In all age groups, diabetes technology use influenced healthcare consumption, yet in adolescence usage decreased and consumption patterns changed. CONCLUSIONS: These findings suggest that contemporary hospital costs of children with diabetes of all ages are driven primarily by the treatment of diabetes, with technology use as an important additive factor. The expected rise in technology use in the near future underlines the importance of insight into resource use and cost-effectiveness studies to evaluate if improved outcomes balance out these short-term costs of modern technology.

Prevalence of and Reasons for Discontinuation of Continuous Subcutaneous Insulin Infusion in People with Type 1 Diabetes: A Systematic Review.

The introduction of continuous subcutaneous insulin infusion in clinical care has led to more optimal glycemic and quality-of-life outcomes, compared with multiple daily injections (MDI). Despite this, some insulin pump users revert back to MDI. The aim of this review was to include the most recent rates of insulin pump discontinuation among people with type 1 diabetes and to identify reasons for and factors associated with discontinuation. A systematic literature search was conducted using the Embase.com, MEDLINE (via OVID), PsycINFO, and CINAHL databases. Titles and abstracts of eligible publications were screened, and baseline characteristics of the included studies were extracted, as were variables in the context of insulin pump use. Data were synthesized into themes: indications for insulin pump initiation, persons with type 1 diabetes (PWD)-reported reasons for, and factors associated with insulin pump discontinuation. A total of 826 eligible publications were identified and 67 were included. Discontinuation percentages ranged from 0% to 30% (median 7%). The most frequently mentioned reasons for discontinuation were wear-related issues (e.g., device attached to the body, interference with daily activities, discomfort, affected body image). Related factors included hemoglobin A1c (HbA1c) (17%), issues with following treatment recommendations (14%), age (11%), gender (9%), side effects (7%), and comorbidity- and complication-related factors (6%). Despite many developments in insulin pump technology, discontinuation rates and PWD-reported reasons for and factors associated with insulin pump discontinuation in more recent studies were comparable to earlier reviews/meta-analyses. Continuation of insulin pump treatment depends on a knowledgeable and willing health care provider (HCP) team and a close match with PWDs' wishes and needs.

Type 1 diabetes management: Room for improvement.

AIMS/HYPOTHESIS: Optimal diabetes care and risk factor management are important to delay micro- and macrovascular complications in individuals with type 1 diabetes (T1D). Ongoing improvement of management strategies requires the evaluation of target achievement and identification of risk factors in individuals who do (or do not) achieve these targets. METHODS: Cross-sectional data were collected from adults with T1D visiting six diabetes centers in the Netherlands in 2018. Targets were defined as glycated hemoglobin (HbA1c) <53 mmol/mol, low-density lipoprotein-cholesterol (LDL-c) <2.6 mmoL/L (no cardiovascular disease [CVD] present) or <1.8 mmoL/L (CVD present), or blood pressure (BP) <140/90 mm Hg. Target achievement was compared for individuals with and without CVD. RESULTS: Data from 1737 individuals were included. Mean HbA1c was 63 mmol/mol (7.9%), LDL-c was 2.67 mmoL/L, and BP 131/76 mm Hg. In individuals with CVD, 24%, 33%, and 46% achieved HbA1c, LDL-c, and BP targets respectively. In individuals without CVD these percentages were 29%, 54%, and 77%, respectively. Individuals with CVD did not have any significant risk factors for HbA1c, LDL-c, and BP target achievement. In comparison, individuals without CVD were more likely to achieve glycemic targets if they were men and insulin pump users. Smoking, microvascular complications, and the prescription of lipid-lowering and antihypertensive medication were negatively associated with glycemic target achievement. No characteristics were associated with LDL-c target achievement. Microvascular complications and antihypertensive medication prescription were negatively associated with BP target attainment. CONCLUSION: Opportunities for improvement of diabetes management exist for the achievement of glycemic, lipid, and BP targets but may differ between individuals with and without CVD.

Do sex differences in paediatric type 1 diabetes care exist? A systematic review.

AIMS/HYPOTHESIS: Sex differences are present in cardiovascular care and in outcomes among adults with type 1 diabetes mellitus, which typically commences in childhood. Whether sex influences care and outcomes in childhood is not known. This systematic review provides an overview of sex differences in children with type 1 diabetes, focusing on patient and disease characteristics, treatment, comorbidities and complications. METHODS: Literature in MEDLINE up to 15 June 2021 was searched, using the terms diabetes mellitus, sex characteristics, sex distribution, children and/or adolescents. All primary outcome studies on children with type 1 diabetes that mentioned a sex difference in outcome were included, with the exception of qualitative studies, case reports or case series. Studies not pertaining to the regular clinical care process and on incidence or prevalence only were excluded. Articles reporting sex differences were identified and assessed on quality and risk of bias using Joanna Briggs Institute critical appraisal tools. Narrative synthesis and an adapted Harvest plot were used to summarise evidence by category. RESULTS: A total of 8640 articles were identified, rendering 90 studies for review (n=643,217 individuals). Studies were of observational design and comprised cohort, cross-sectional and case-control studies. Most of the included studies showed a higher HbA1c in young female children both at diagnosis (seven studies, n=22,089) and during treatment (20 out of 21 studies, n=144,613), as well as a steeper HbA1c increase over time. Many studies observed a higher BMI (all ages, ten studies, n=89,700; adolescence, seven studies, n=33,153), a higher prevalence of being overweight or obese, and a higher prevalence of dyslipidaemia among the female sex. Hypoglycaemia and partial remission occurred more often in male participants, and ketoacidosis (at diagnosis, eight studies, n=3561) and hospitalisation was more often seen in female participants. Most of the findings showed that female participants used pump therapy more frequently (six studies, n=211,324) and needed higher insulin doses than male participants. Several comorbidities, such as thyroid disease and coeliac disease, appeared to be more common in female participants. All studies reported lower quality of life in female participants (15 studies, n=8722). Because the aim of this study was to identify sex differences, studies with neutral outcomes or minor differences may have been under-targeted. The observational designs of the included studies also limit conclusions on the causality between sex and clinical outcomes. CONCLUSIONS/INTERPRETATION: Sex disparities were observed throughout diabetes care in children with type 1 diabetes. Several outcomes appear worse in young female children, especially during adolescence. Focus on the cause and treatment of these differences may provide opportunities for better outcomes. REGISTRATION: This systematic review is registered in PROSPERO (CRD42020213640).

Fasting and meal-stimulated serum C-peptide in long-standing type 1 diabetes mellitus.

AIMS: This study aims to evaluate the stability of C-peptide over time and to compare fasting C-peptide and C-peptide response after mixed-meal tolerance test (MMTT) at T90 or T120 with C-peptide area under the curve (AUC) in long-standing type 1 diabetes. METHODS: We included 607 type 1 diabetes individuals with diabetes duration >5 years. C-peptide concentrations (ultrasensitive assay) were collected in the fasting state, and in a subpopulation after MMTT (T0, just prior to, T30-T60-T90-T120, 30-120 min after ingestion of mixed-meal) (n = 168). Fasting C-peptide concentrations (in n = 535) at Year 0 and Year 1 were compared. The clinical determinants associated with residual C-peptide secretion and the correspondence of C-peptide at MMTT T90 / T120 and total AUC were assessed. RESULTS: A total of 153 participants (25%) had detectable fasting serum C-peptide (i.e ≥ 3.8 pmol/L). Fasting C-peptide was significantly lower at Year 1 (p < 0.001, effect size = -0.16). Participants with higher fasting C-peptide had a higher age at diagnosis and shorter disease duration and were less frequently insulin pump users. Overall, 109 of 168 (65%) participants had both non-detectable fasting and post-meal serum C-peptide concentrations. The T90 and T120 C-peptide values at MMTT were concordant with total AUC. In 17 (10%) individuals, C-peptide was only detectable at MMTT and not in the fasting state. CONCLUSIONS: Stimulated C-peptide was detectable in an additional 10% of individuals compared with fasting in individuals with >5 years of diabetes duration. T90 and T120 MMTT measurements showed good concordance with the MMTT total AUC. Overall, there was a decrease of C-peptide at 1-year follow-up.

Tolerogenic dendritic cells pulsed with islet antigen induce long-term reduction in T-cell autoreactivity in type 1 diabetes patients.

Introduction: Restoration of immune tolerance may halt progression of autoimmune diseases. Tolerogenic dendritic cells (tolDC) inhibit antigen-specific proinflammatory T-cells, generate antigen-specific regulatory T-cells and promote IL-10 production in-vitro, providing an appealing immunotherapy to intervene in autoimmune disease progression. Methods: A placebo-controlled, dose escalation phase 1 clinical trial in nine adult patients with long-standing type 1 diabetes (T1D) demonstrated the safety and feasibility of two (prime-boost) vaccinations with tolDC pulsed with a proinsulin peptide. Immunoregulatory effects were monitored by antigen-specific T-cell assays and flow and mass cytometry. Results: The tolDC vaccine induced a profound and durable decline in pre-existing autoimmune responses to the vaccine peptide up to 3 years after therapy and temporary decline in CD4 and CD8+ T-cell responses to other islet autoantigens. While major leukocyte subsets remained stable, ICOS+CCR4+TIGIT+ Tregs and CD103+ tissue-resident and CCR6+ effector memory CD4+ T-cells increased in response to the first tolDC injection, the latter declining thereafter below baseline levels. Discussion: Our data identify immune correlates of mechanistic efficacy of intradermally injected tolDC reducing proinsulin autoimmunity in T1D.

Differences in retinopathy prevalence and associated risk factors across 11 countries in three continents: A cross-sectional study of 156,090 children and adolescents with type 1 diabetes.

OBJECTIVE: To examine the prevalence, time trends, and risk factors of diabetic retinopathy (DR) among youth with type 1 diabetes (T1D) from 11 countries (Australia, Austria, Denmark, England, Germany, Italy, Luxemburg, Netherlands, Slovenia, United States, and Wales). SUBJECTS AND METHODS: Data on individuals aged 10-21 years with T1D for >1 year during the period 2000-2020 were analyzed. We used a cross-sectional design using the most recent year of visit to investigate the time trend. For datasets with longitudinal data, we aggregated the variables per participant and observational year, using data of the most recent year to take the longest observation period into account. DR screening was performed through quality assured national screening programs. Multiple logistic regression models adjusted for the year of the eye examination, age, gender, minority status, and duration of T1D were used to evaluate clinical characteristics and the risk of DR. RESULTS: Data from 156,090 individuals (47.1% female, median age 15.7 years, median duration of diabetes 5.2 years) were included. Overall, the unadjusted prevalence of any DR was 5.8%, varying from 0.0% (0/276) to 16.2% between countries. The probability of DR increased with longer disease duration (aORper-1-year-increase  = 1.04, 95% CI: 1.03-1.04, p < 0.0001), and decreased over time (aORper-1-year-increase  = 0.99, 95% CI: 0.98-1.00, p = 0.0093). Evaluating possible modifiable risk factors in the exploratory analysis, the probability of DR increased with higher HbA1c (aORper-1-mmol/mol-increase-in-HbA1c  = 1.03, 95% CI: 1.03-1.03, p < 0.0001) and was higher among individuals with hypertension (aOR = 1.24, 95% CI: 1.11-1.38, p < 0.0001) and smokers (aOR = 1.30, 95% CI: 1.17-1.44, p < 0.0001). CONCLUSIONS: The prevalence of DR in this large cohort of youth with T1D varied among countries, increased with diabetes duration, decreased over time, and was associated with higher HbA1c, hypertension, and smoking.

The COVID-19 Pandemic Affects Seasonality, With Increasing Cases of New-Onset Type 1 Diabetes in Children, From the Worldwide SWEET Registry.

OBJECTIVE: To analyze whether the coronavirus disease 2019 (COVID-19) pandemic increased the number of cases or impacted seasonality of new-onset type 1 diabetes (T1D) in large pediatric diabetes centers globally. RESEARCH DESIGN AND METHODS: We analyzed data on 17,280 cases of T1D diagnosed during 2018-2021 from 92 worldwide centers participating in the SWEET registry using hierarchic linear regression models. RESULTS: The average number of new-onset T1D cases per center adjusted for the total number of patients treated at the center per year and stratified by age-groups increased from 11.2 (95% CI 10.1-12.2) in 2018 to 21.7 (20.6-22.8) in 2021 for the youngest age-group, <6 years; from 13.1 (12.2-14.0) in 2018 to 26.7 (25.7-27.7) in 2021 for children ages 6 to <12 years; and from 12.2 (11.5-12.9) to 24.7 (24.0-25.5) for adolescents ages 12-18 years (all P < 0.001). These increases remained within the expected increase with the 95% CI of the regression line. However, in Europe and North America following the lockdown early in 2020, the typical seasonality of more cases during winter season was delayed, with a peak during the summer and autumn months. While the seasonal pattern in Europe returned to prepandemic times in 2021, this was not the case in North America. Compared with 2018-2019 (HbA1c 7.7%), higher average HbA1c levels (2020, 8.1%; 2021, 8.6%; P < 0.001) were present within the first year of T1D during the pandemic. CONCLUSIONS: The slope of the rise in pediatric new-onset T1D in SWEET centers remained unchanged during the COVID-19 pandemic, but a change in the seasonality at onset became apparent.

Cardiovascular risk management in people with type 1 diabetes: performance using three guidelines.

INTRODUCTION: Cardiovascular disease (CVD) is the leading cause of mortality in individuals with type 1 diabetes mellitus (T1DM). Cardiovascular risk management is therefore essential in the management of individuals with T1DM. This study describes the performance of lipid and blood pressure management in individuals with T1DM using three guidelines. RESEARCH DESIGN AND METHODS: Individuals ≥18 years with T1DM, treated with insulin for ≥1 year, visiting Diabeter or the University Medical Center Groningen between January 1, 2018 and December 31, 2018, were included. Lipid and blood pressure management were examined using the Dutch, American Diabetes Association (ADA) and National Institute for Health and Care Excellence (NICE) guidelines. Concordance of recommended and prescribed lipid-lowering (LLM) or antihypertensive medication (AHM) was assessed per guideline and 10-year age groups. Achievement of treatment targets was assessed for those prescribed medication. RESULTS: A total of 1855 individuals with T1DM were included. LLM and AHM was prescribed in 19% and 17%, respectively. In individuals recommended LLM, this was prescribed in 22%-46% according to Dutch, ADA or NICE guideline recommendations. For individuals recommended AHM, this was prescribed in 52%-75%. Recommended and actual prescription of LLM and AHM increased over age for all three guidelines. However, discordance between treatment recommendation and medication prescribed was higher in younger, compared with older, age groups. Low-density lipoprotein-cholesterol targets were achieved by 50% (without CVD) and 31% (with CVD) of those prescribed LLM. The blood pressure target was achieved by 46% of those prescribed AHM. CONCLUSION: This study suggests that there is undertreatment of lipid and blood pressure according to guideline recommendations, particularly in younger age groups. Treatment targets are not met by most individuals prescribed medication, while guidelines recommendations differ considerably. We recommend to investigate the factors influencing undertreatment of lipid and blood pressure management in individuals with T1DM.

How low is really low? Comparison of two C-peptide assays to establish residual C-peptide production in type 1 diabetes.

INTRODUCTION: C-peptide is an important marker to assess residual insulin production in individuals with type 1 diabetes (T1D). The accuracy and detection limits of C-peptide assays are important to detect C-peptide microsecretion and to reliably observe changes over time in these people. We compared and verified two commercially available assays able to measure C-peptide in the picomolar range. METHODS: The ultrasensitive Mercodia enzyme-linked immunosorbent C-peptide assay (ELISA) was compared with the Beckman immunoradiometric assay (IRMA) for C-peptide, assessing reproducibility (coefficient of variation [CV]), limit of blank (LoB), limit of detection (LoD) and limit of quantitation (LoQ). RESULTS: For both assays within-run and between-run variation were high at the low (around the detection limit) C-peptide concentration range, with CVs of around 40%. LoB values for the ultrasensitive ELISA and the IRMA were 1.3 and 0.16 pmol/L respectively. LoD values were 2.4 and 0.54 pmol/L respectively. LoQ values were 9.7 and 3.8 pmol/L respectively. Only the IRMA met the specifications claimed by the manufacturer. CONCLUSIONS: The IRMA provided the lowest threshold for quantification of serum C-peptide. LoQ of commercially available assays should be established in-house before applying them in research studies and clinical trials in which low C-peptide levels have clinical or scientific relevance.

International comparison of glycaemic control in people with type 1 diabetes: an update and extension.

AIMS: To update and extend a previous cross-sectional international comparison of glycaemic control in people with type 1 diabetes. METHODS: Data were obtained for 520,392 children and adults with type 1 diabetes from 17 population and five clinic-based data sources in countries or regions between 2016 and 2020. Median HbA1c (IQR) and proportions of individuals with HbA1c < 58 mmol/mol (<7.5%), 58-74 mmol/mol (7.5-8.9%) and ≥75 mmol/mol (≥9.0%) were compared between populations for individuals aged <15, 15-24 and ≥25 years. Logistic regression was used to estimate the odds ratio (OR) of HbA1c < 58 mmol/mol (<7.5%) relative to ≥58 mmol/mol (≥7.5%), stratified and adjusted for sex, age and data source. Where possible, changes in the proportion of individuals in each HbA1c category compared to previous estimates were calculated. RESULTS: Median HbA1c varied from 55 to 79 mmol/mol (7.2 to 9.4%) across data sources and age groups so a pooled estimate was deemed inappropriate. OR (95% CI) for HbA1c < 58 mmol/mol (<7.5%) were 0.91 (0.90-0.92) for women compared to men, 1.68 (1.65-1.71) for people aged <15 years and 0.81 (0.79-0.82) aged15-24 years compared to those aged ≥25 years. Differences between populations persisted after adjusting for sex, age and data source. In general, compared to our previous analysis, the proportion of people with an HbA1c  < 58 mmol/l (<7.5%) increased and proportions of people with HbA1c ≥ 75 mmol/mol (≥9.0%) decreased. CONCLUSIONS: Glycaemic control of type 1 diabetes continues to vary substantially between age groups and data sources. While some improvement over time has been observed, glycaemic control remains sub-optimal for most people with Type 1 diabetes.

DPARD: rationale, design and initial results from the Dutch national diabetes registry.

BACKGROUND: Treatment of diabetes mellitus has majorly improved over the past century, however, the disease burden is high and its prevalence still expanding. Further insight in the diabetes population is imperative to improve the quality of diabetes care by enhancement of knowledge-based diabetes management strategies. To this end, in 2017 a Dutch nationwide consortium of diabetologists, paediatric endocrinologists, and diabetes patients has founded a national outpatient diabetes care registry named Dutch Pediatric and Adult Registry of Diabetes (DPARD). We aim to describe the implementation of DPARD and to provide an overview of the characteristics of patients included during the first 2 years. METHODS: For the DPARD cohort with long-term follow-up of observational nature, hospital data are gathered directly from electronic health records and securely transferred and stored. DPARD provides weekly updated clinical information on the diabetes population care on a hospital-level benchmarked against the national average. RESULTS: Between November 2017 and January 2020, 20,857 patients were included from 8 (11%) Dutch hospitals with a level of care distribution representative of all diabetic outpatients in the Netherlands. Among patients with known diabetes type, 41% had type 1 diabetes, 51% type 2 diabetes, and 8% had diabetes due to other causes. Characteristics of the total patient population were similar to patients with unknown diabetes classification. HbA1c levels decreased over the years, while BMI levels showed an increase over time. CONCLUSIONS: The national DPARD registry aims to facilitate investigation of prevalence and long-term outcomes of Dutch outpatients with diabetes mellitus and their treatment, thus allowing for quality improvement of diabetes care as well as allowing for comparison of diabetes care on an international level.

Losing Track of Lipids in Children and Adolescents with Type 1 Diabetes: Towards Individualized Patient Care.

AIM: To assess 1) the prevalence of children and adolescents with type 1 diabetes (T1D) changing from low-risk into borderline-high-risk lipid levels or from borderline-high-risk into high-risk lipid levels ('lose track of lipids') and 2) the power of a risk score including the determinants HbA1c, body mass index (BMI), gender, age, diabetes duration and ethnicity in predicting which patients lose track of lipids. METHODS: 651 children and adolescents with T1D were included in this longitudinal retrospective cohort study. Lipid dynamics and the impact of the risk score on losing track of lipids were evaluated. Kaplan-Meier analysis was used to estimate screening intervals. RESULTS: 31-43% percent of the patients had lost track of one or more lipids at the next lipid measurement. This happened more frequently in patients with a low-risk lipid level at start. Depending on the lipid parameter, 5% of patients with low-risk lipid levels lost track of lipids after 13-23 months. The risk score based on concomitant information on the determinants was moderately able to predict which patients would lose track of lipids on the short term. CONCLUSIONS: A considerable number of children and adolescents with T1D loses track of lipids and does so within a 2-year screening interval. The predictive power of a risk score including age, BMI, gender, HbA1c, diabetes duration and ethnicity is only moderate. Future research should focus on another approach to the determinants used in this study or other determinants predictive of losing track of lipids on the short term.