No association between long-chain n-3 fatty acid intake during pregnancy and risk of type 1 diabetes in offspring in two large Scandinavian pregnancy cohorts.

AIMS/HYPOTHESIS: The aim of this study was to investigate whether higher dietary intake of marine n-3 fatty acids during pregnancy is associated with a lower risk of type 1 diabetes in children. METHODS: The Danish National Birth Cohort (DNBC) and the Norwegian Mother, Father and Child Cohort Study (MoBa) together include 153,843 mother-child pairs with prospectively collected data on eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) intake during pregnancy from validated food frequency questionnaires. Type 1 diabetes diagnosis in children (n=634) was ascertained from national diabetes registries. RESULTS: There was no association between the sum of EPA and DHA intake during pregnancy and risk of type 1 diabetes in offspring (pooled HR per g/day of intake: 1.00, 95% CI 0.88, 1.14), with consistent results for both the MoBa and the DNBC. Robustness analyses gave very similar results. CONCLUSIONS/INTERPRETATION: Initiation of a trial of EPA and DHA during pregnancy to prevent type 1 diabetes in offspring should not be prioritised.

The effect of stress on the antibody response after vaccination in children aged 0-18 years: A systematic review.

Stress has been associated with less effective vaccine responses in adults. This review aims to investigate the evidence for a similar association in children. A systematic review search was conducted in January 2021 in three databases: Medline, Embase and PsycInfo. An updated search of the Medline database was systematically conducted until the most recent update on September 25th, 2023, to ensure the inclusion of the most current research available. Keywords related to stress, vaccines and children were used, and a total of 7263 (+1528) studies were screened by two independent investigators. Six studies met the inclusion criteria for data extraction and analysis. For quality assessment of the studies, the risk of bias in non-randomized studies-of interventions (ROBINS-I) tool was applied. Most of the studies suggest a negative role of stress on vaccine responses. However, the scarcity of studies, lack of confirmatory studies, risk of bias and heterogeneity according to age, type of vaccine, measures of stress and vaccine responses prevent a clear conclusion. Future studies should emphasize the use of as strict study designs as possible, including well-defined stress metrics and thorough examination of both pre- and post-vaccination responses. Systematic review registration: Prospero CRD42021230490.

Heterogeneity in glycaemic control in children and adolescents with type 1 diabetes: A latent class trajectory analysis of Danish nationwide data.

AIMS: Suboptimal glycaemic control in children and adolescents with type 1 diabetes is prevalent and associated with increased risk of diabetes-related complications and mortality later in life. First, we aimed to identify distinct glycated haemoglobin (HbA1c) trajectories in children and adolescents (2-19 years) with type 1 diabetes. Second, we examined their associations with clinical and socio-demographic factors. METHODS: Data were obtained from the Danish Registry of Childhood and Adolescent Diabetes (DanDiabKids) comprising all Danish children and adolescents diagnosed with type 1 diabetes from 1996 to 2019. Subgroups of distinct mean trajectories of HbA1c were identified using data-driven latent class trajectory modelling. RESULTS: A total of 5889 children (47% female) had HbA1c measured a median of 6 times (interquartile range 3-8) and contributing to 36,504 measurements. We identified four mean HbA1c trajectories, referred to as 'Stable but elevated HbA1c' (83%), 'Increasing HbA1c' (5%), 'Late HbA1c peak' (7%), and 'Early HbA1c peak' (5%). Compared to the 'Stable but elevated HbA1c' group, the three other groups presented rapidly deteriorating glycaemic control during late childhood or adolescence, had higher HbA1c at study entry, and included fewer pump users, higher frequency of inadequate blood glucose monitoring, more severe hypoglycaemic events, lower proportions with Danish origin, and worse educational status of parents. The groups also represented significant differences by healthcare region. CONCLUSIONS: Children and adolescents with type 1 diabetes experience heterogenous trajectories with different timings and magnitudes of the deterioration of HbA1c levels, although the majority follow on average a stable, yet elevated HbA1c trajectory. The causes and long-term health implications of these heterogenous trajectories need to be addressed.

Correction: School performance in Danish children exposed to maternal type 1 diabetes in utero: A nationwide retrospective cohort study.

[This corrects the article DOI: 10.1371/journal.pmed.1003977.].

School performance in Danish children exposed to maternal type 1 diabetes in utero: A nationwide retrospective cohort study.

BACKGROUND: Conflicting results have been reported concerning possible adverse effects on the cognitive function of offspring of mothers with type 1 diabetes (O-mT1D). Previous studies have included offspring of parents from the background population (O-BP), but not offspring of fathers with type 1 diabetes (O-fT1D) as the unexposed reference group. METHODS AND FINDINGS: This is a population-based retrospective cohort study from 2010 to 2016. Nationally standardized school test scores (range, 1 to 100) were obtained for public school grades 2, 3, 4, 6, and 8 in O-mT1D and compared with those in O-fT1D and O-BP. Of the 622,073 included children, 2,144 were O-mT1D, and 3,474 were O-fT1D. Multiple linear regression models were used to compare outcomes, including the covariates offspring with type 1 diabetes, parity, number of siblings, offspring sex, smoking during pregnancy, parental age, and socioeconomic factors. Mean test scores were 54.2 (standard deviation, SD 24.8) in O-mT1D, 54.4 (SD 24.8) in O-fT1D, and 56.4 (SD 24.7) in O-BP. In adjusted analyses, the mean differences in test scores were -1.59 (95% CI -2.48 to -0.71, p < 0.001) between O-mT1D and O-BP and -0.78 (95% CI -1.48 to -0.08, p = 0.03) between O-fT1D and O-BP. No significant difference in the adjusted mean test scores was found between O-mT1D and O-fT1D (p = 0.16). The study's limitation was no access to measures of glycemic control during pregnancy. CONCLUSIONS: O-mT1D achieved lower test scores than O-BP but similar test scores compared with O-fT1D. Glycemic control during pregnancy is essential to prevent various adverse pregnancy outcomes in women with type 1 diabetes. However, the present study reduces previous concerns regarding adverse effects of in utero hyperglycemia on offspring cognitive function.

Association of type 1 diabetes and educational achievement in 16-20-year-olds: A Danish nationwide register study.

AIMS: The objective of the study was to compare grade point averages (GPAs) on compulsory school exit exams (exam GPA) and educational attainment at age 16 and 20 for individuals with and without type 1 diabetes. METHODS: This study was a population-based retrospective cohort study, which included the 1991 to 1998 birth cohorts in Denmark. Follow-up was conducted at age 16 and 20 (follow-up period; 1 January, 2007 to 31 December, 2018). There were 2083 individuals with and 555,929 individuals without type 1 diabetes. Linear regression and generalized linear models compared outcomes with and without adjustments for socio-economic characteristics. RESULTS: A total of 558,012 individuals (51% males) were followed to the age of 20. Having type 1 diabetes was associated with a lower exam GPA when adjusting for socio-economic status (difference: -0.05 (95% CI, -0.09 to -0.01), a higher relative risk of not completing compulsory school by age 16 (1.37, 95% CI, 1.22 to 1.53)), and a higher relative risk of not completing or being enrolled in upper secondary education by age 20 (1.05, 95% CI, 1.00 to 1.10). Haemoglobin A1c (HbA1c) <58 mmol/mol (7.5%), >7 BGM/day and insulin pump use were associated with better educational achievement. CONCLUSION: Type 1 diabetes was associated with a marginally lower exam GPA and a higher risk of not completing compulsory school by age 16 and lower educational attainment by age 20. The findings were modified by HbA1c, BGM and insulin pump use.

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.

Center differences in diabetes treatment outcomes among children with type 1 diabetes: A nationwide study of 3866 Danish children.

OBJECTIVE: Mean differences in HbA1c across centers are well established, but less well understood. The aim was to assess whether differences in patient case-mix can explain the variation in mean HbA1c between pediatric diabetes centers in Denmark. The association between HbA1c , frequency of blood glucose monitoring (BGM), treatment modality, and center visits was investigated. RESEARCH DESIGN AND METHODS: This longitudinal nationwide study included 3866 Danish children with type 1 diabetes from 2013 to 2017 (n = 12,708 child-year observations) from 16 different pediatric diabetes centers. Mean HbA1c , proportion of children reaching HbA1c treatment target (HbA1c  ≤ 58 mmol/mol [7.5%]) were compared across centers using linear regression models. This was done with and without adjustment for socioeconomic characteristics (patient case-mix). RESULTS: The mean difference in HbA1c during follow-up was 11.6 mmol/mol (95% CI 7.9, 15.3) (1.1% [95% CI 0.7, 1.4]) when comparing the centers with the lowest versus highest mean HbA1c . The difference was attenuated and remained significant after adjustment for the patient case-mix (difference: 10.5 mmol/mol [95% CI 6.8, 14.2] (1.0% [95% CI 0.6, 1.3])). Overall, 6.8% of the differences in mean HbA1c across centers were explained by differences in the patient case-mix. Across centers, more frequent BGM was associated with lower HbA1c . The proportion of insulin pump users and number of visits was not associated with HbA1c . CONCLUSION: In a setting of universal health care, large differences in HbA1c across centers were found, and could not be explained by patient background, number of visits or use of technology. Only BGM was associated with center HbA1c .

Trajectory and predictors of HbA1c in children and adolescents with type 1 diabetes-A Danish nationwide cohort study.

OBJECTIVES: Poor glycemic control in type 1 diabetes increases the risk of chronic complications and it is essential to identify life periods and predictors associated with deteriorating HbA1c . The aim was to describe specific HbA1c trajectories in Danish children and adolescents with type 1 diabetes and study associations with clinical and sociodemographic factors. RESEARCH DESIGN AND METHODS: 5889 children with type 1 diabetes were included from the nationwide Danish Registry of Childhood and Adolescent Diabetes with annual visits during 1996-2019. Trajectories of HbA1c were modeled with linear mixed-effects models (using age as time scale, included as cubic spline) and with an individual-specific random intercept and slope. The following cofactors were included stepwise into the model: sex, age at diagnosis, calendar year, parental education, immigrant status, health care region, blood glucose monitoring (BGM) frequency, treatment modalities: continuous subcutaneous insulin infusion (pump) versus multiple daily insulin injection therapy (pen) and continuous glucose monitoring. RESULTS: HbA1c overall increased during age while there was a significant decreasing secular trend. Older age at diagnosis was associated with a steeper trajectory, and non-Danish origin and shorter parental education were each associated with higher levels of HbA1c across age. A lower BGM frequency was associated with a markedly poorer HbA1c trajectory, while no significant differences were shown for different treatment modalities. CONCLUSIONS: Glycemic outcome worsened with age during childhood and adolescence, which is of clinical concern. Important predictors for a poorer glycemic trajectory were later age at diabetes diagnosis, shorter parental education, non-Danish origin and, in particular low BGM frequency.

A collaborative comparison of international pediatric diabetes registries.

BACKGROUND: An estimated 1.1 million children and adolescents aged under 20 years have type 1 diabetes worldwide. Principal investigators from seven well-established longitudinal pediatric diabetes registries and the SWEET initiative have come together to provide an international collaborative perspective and comparison of the registries. WORK FLOW: Information and data including registry characteristics, pediatric participant clinical characteristics, data availability and data completeness from the Australasian Diabetes Data Network (ADDN), Danish Registry of Childhood and Adolescent Diabetes (DanDiabKids), Diabetes prospective follow-up registry (DPV), Norwegian Childhood Diabetes Registry (NCDR), National Paediatric Diabetes Audit (NPDA), Swedish Childhood Diabetes Registry (Swediabkids), T1D Exchange Quality Improvement Collaborative (T1DX-QI), and the SWEET initiative was extracted up until 31 December 2020. REGISTRY OBJECTIVES AND OUTCOMES: The seven diabetes registries and the SWEET initiative collectively show data of more than 900 centers and around 100,000 pediatric patients, the majority with type 1 diabetes. All share the common objectives of monitoring treatment and longitudinal outcomes, promoting quality improvement and equality in diabetes care and enabling clinical research. All generate regular benchmark reports. Main differences were observed in the definition of the pediatric population, the inclusion of adults, documentation of CGM metrics and collection of raw data files as well as linkage to other data sources. The open benchmarking and access to regularly updated data may prove to be the most important contribution from registries. This study describes aspects of the registries to enable future collaborations and to encourage the development of new registries where they do not exist.

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.

Association of type 1 diabetes and school wellbeing: a population-based cohort study of 436,439 Danish schoolchildren.

AIMS/HYPOTHESIS: We aimed to examine the association of type 1 diabetes with school wellbeing among Danish children. METHODS: This is a population-based cohort study involving 436,439 Danish children, of which 1499 had a confirmed diagnosis of type 1 diabetes. The children were enrolled in grade levels 4 to 9 (middle school) in Danish public schools in the years 2014-2017. Questionnaire outcomes from the yearly National Wellbeing Survey related to self-efficacy, perceived competences, peer and teacher support, bullying and somatic symptoms were analysed. Ordered logistic regression was used to compare outcomes of children with and without type 1 diabetes, and to compare subgroups of children with type 1 diabetes by different levels of HbA1c and diabetes duration. Primary outcomes were answers to seven pre-specified questionnaire items (scale, 1 to 5). RESULTS: A total of 817,679 questionnaires were initiated, of which n = 2681 were from children with type 1 diabetes. Compared with the background population, children with type 1 diabetes expressed more peer support; adjusted OR 1.17 (95% CI 1.08, 1.27). Children with diabetes also reported more often having a headache; adjusted OR 1.09 (95% CI 1.00, 1.19). Overall, children with poor glycaemic control (HbA1c >70 mmol/mol) had worse outcomes on the wellbeing measures compared with the background population. Even after adjusting for socioeconomic status, they still reported significantly worse perceived competences, less teacher support and more somatic symptoms (stomach ache and headache). CONCLUSIONS/INTERPRETATION: In Denmark, children with type 1 diabetes generally feel well supported in school but have more headaches than other children. Poor glycaemic control is associated with worse psychological school-related wellbeing. Graphical abstract.

Temporal trends in diabetic ketoacidosis at diagnosis of paediatric type 1 diabetes between 2006 and 2016: results from 13 countries in three continents.

AIMS/HYPOTHESIS: The aim of this work was to evaluate geographical variability and trends in the prevalence of diabetic ketoacidosis (DKA), between 2006 and 2016, at the diagnosis of childhood-onset type 1 diabetes in 13 countries over three continents. METHODS: An international retrospective study on DKA at diagnosis of diabetes was conducted. Data on age, sex, date of diabetes diagnosis, ethnic minority status and presence of DKA at diabetes onset were obtained from Australia, Austria, Czechia, Denmark, Germany, Italy, Luxembourg, New Zealand, Norway, Slovenia, Sweden, USA and the UK (Wales). Mean prevalence was estimated for the entire period, both overall and by country, adjusted for sex and age group. Temporal trends in annual prevalence of DKA were estimated using logistic regression analysis for each country, before and after adjustment for sex, age group and ethnic minority status. RESULTS: During the study period, new-onset type 1 diabetes was diagnosed in 59,000 children (median age [interquartile range], 9.0 years [5.5-11.7]; male sex, 52.9%). The overall adjusted DKA prevalence was 29.9%, with the lowest prevalence in Sweden and Denmark and the highest in Luxembourg and Italy. The adjusted DKA prevalence significantly increased over time in Australia, Germany and the USA while it decreased in Italy. Preschool children, adolescents and children from ethnic minority groups were at highest risk of DKA at diabetes diagnosis in most countries. A significantly higher risk was also found for females in Denmark, Germany and Slovenia. CONCLUSIONS/INTERPRETATION: DKA prevalence at type 1 diabetes diagnosis varied considerably across countries, albeit it was generally high and showed a slight increase between 2006 and 2016. Increased awareness of symptoms to prevent delay in diagnosis is warranted, especially in preschool children, adolescents and children from ethnic minority groups.

Episodes of severe hypoglycemia is associated with a progressive increase in hemoglobin A1c in children and adolescents with type 1 diabetes.

OBJECTIVE: To investigate the trajectory in glycemic control following episodes of severe hypoglycemia (SH) among children and adolescents with type 1 diabetes (T1D). METHODS: A Danish national population-based study comprising data from 2008-17. SH was defined according to the 2014 ISPAD guidelines. A mixed model was applied with HbA1c as outcome and SH episodes and time since first episode as explanatory variables. Data were adjusted for age, gender and diabetes duration. RESULTS: A total of 4244 children (51.6% boys) with 18 793 annual outpatient visits were included. Mean (SD) age at diabetes onset was 9.0 (4.1) years. Median diabetes duration at inclusion in the study was 1.2 (Q1 = 0.9, Q3 = 3.0) years, and median diabetes duration at last visit was 5.0 (Q1 = 2.7, Q3 = 8.1) years. A total of 506 children experienced at least one episode of SH during the nine-year follow-up; 294 children experienced one episode, 115 two episodes and 97 three or more episodes of SH. HbA1c increased with episodes of SH and in the years following the first episode. The glycemic trajectory peaked 2 to 3 years after an SH episode. The accumulated deterioration in glycemic control was in the range of 5% in patients with two or more episodes equivalent to an increase in HbA1c of 4 mmol/mol (HbA1c ~0.4%). CONCLUSION: SH was followed by a progressive and lasting increase in HbA1c among Danish children and adolescents with T1D. Thus, in addition to the known risk of new episodes of hypoglycemia and cognitive impairment, SH contributes to long-term diabetes complications.

The DISABKIDS generic and diabetes-specific modules are valid but not directly comparable between Denmark, Sweden, and Norway.

BACKGROUND/OBJECTIVES: Government guidance promote benchmarking comparing quality of care including both clinical values and patient reported outcome measures in young persons with type 1 diabetes. The aim was to test if the Nordic DISABKIDS health-related quality of life (HrQoL) modules were construct valid and measurement comparable within the three Nordic countries. METHODS: Data from three DISABKIDS validation studies in Sweden, Denmark, and Norway were compared using Rasch and the graphical log-linear Rasch modeling. Monte Carlo methods were used to estimate reliability coefficient and target was defined as the point with the lowest SE of the mean. Self-report data were available from 99 Danish (8-18 years), 103 Norwegian (7-19 years), and 131 Swedish (8-18 years) young people. RESULTS: For the DISABKIDS higher scores on most subscales were noted in the Norwegian population. The Swedish sample had a significantly higher score on the "Diabetes treatment" subscale and scores closer to optimal target than the other countries. For each country, construct validity and sensitivity were acceptable when accounting for differential item function (DIF) and local dependency (LD). Less LD and DIF were found if only Denmark and Norway were included. The combined model was reliable; however, some differences were noted in the scale translations relating to the stem and response alternatives, which could explain the discrepancies. CONCLUSION: The Nordic versions of the DISABKIDS questionnaires measures valid and reliable HrQoL both within and between countries when adjusted for DIF and LD. Adjusting the Likert scales to the same respond categories may improve comparability.

Bone turnover markers during the remission phase in children and adolescents with type 1 diabetes.

BACKGROUND AND AIM: In rodents, osteocalcin (OCN) stimulates insulin production and insulin sensitivity, both important factors during partial remission in humans with type 1 diabetes (T1D). However, decreased OCN has been reported in both adult and pediatric T1D. This study aims at investigating bone turnover and partial remission in children and adolescents with recent onset T1D. SUBJECTS AND METHODS: Ninety-nine individuals (33% girls) were recruited within 3 months of T1D onset and examined three times, 6 months apart. Outcome variables were bone formation markers OCN and procollagen type 1 amino-terminal propeptide (P1NP) and the bone resorption marker C-terminal crosslinked telopeptide of type 1 collagen (CTX). Dependent variables included IDAA1c (surrogate marker of partial remission), total body bone mineral density (BMD) and stimulated C-peptide as representative of endogenous insulin production. RESULTS: OCN- and P1NP Z-scores were significantly decreased throughout the study, whereas CTX Z-scores were increased. None of the bone turnover markers changed significantly between visits. Total body BMD Z-score did not change during the study but was significantly higher than the reference population at visit 2 (P = .035). There were no differences in the bone turnover markers for those in partial remission as defined by either C-peptide or IDAA1c at any visit. The individual change in CTX Z-score was negatively associated with the increase of IDAA1c (P = .030) independent of C-peptide decline (P = .034). CONCLUSION: Bone turnover markers indicate increased bone resorption and decreased bone formation during the first year of T1D. The negative association between bone resorption and IDAA1c might represent compensatory mechanisms affecting insulin sensitivity.

Screening for retinopathy in children with type 1 diabetes in Denmark.

BACKGROUND/OBJECTIVE: Children with type 1 diabetes (T1D) are screened regularly for retinopathy with fundus photography to prevent visual impairment. According to Danish national guidelines, screening should take place at age 12, 15, and 18 years after minimum 3 years of diabetes. As glycemic control has improved, prevalence of retinopathy is expected to be decreased. The aim of this study is to investigate the prevalence, degree, and progression of retinopathy in children with T1D and to explore if screening at 12 years is currently indicated in Denmark. METHODS: Data on all Danish children with onset of T1D from 2003 to 2013 (n = 2943) were collected from the "DanDiabKids" registry. For children with registered screenings (n = 2382), prevalence of retinopathy at 12, 15, and 18 years was determined. In children with retinopathy, subsequent screenings were studied to reveal if retinopathy was persistent or temporary. RESULTS: Prevalence of retinopathy at 12, 15, and 18 years was 0.9%, 2.3%, and 3.1%, respectively. Minimal background retinopathy was seen in over 90% and 100% at 12 years. In available re-screenings, retinopathy resolved spontaneously in 87.5% of all cases and 100% of cases at 12 years. CONCLUSIONS: The prevalence of retinopathy in Danish children with T1D was low. At 12 years, prevalence was 0.9% and exclusively minimal background retinopathy with 100% remission in re-screenings. Thus, screening at this age does not seem to have significant clinical relevance. We propose more individualized screening selection before the age of 15.

Geographical variation in the incidence of type 1 diabetes in the Nordic countries: A study within NordicDiabKids.

BACKGROUND: The incidence of type 1 diabetes (T1D) is high in the Nordic countries with geographic differences between as well as within countries. OBJECTIVE: To describe the geographical distribution of the incidence of T1D among children in four Nordic countries, an area where the population is considered genetically similar. METHODS: Data on children 0 to 14 years of age and diagnosed with T1D 2006 to 2011 was collected from four Nordic national pediatric quality diabetes registries. Data included year of diagnosis (2006-2011), sex, and age at diagnosis. Figures for number of children at risk during 2006 to 2011-as well as total population, proportion with foreign background and size of populated areas of geographic regions-were collected from official statistics. RESULTS: The total incidence during the study period for all four countries was 35.7/100 000 person years but differed between the countries (range 18.2-44.1; P < .001). The incidence difference between the countries was most obvious in the highest age group, 10 to 14 years of age, whereas there was no difference in the youngest age group 0 to 5 years of age. Iceland had similar incidence in the entire country, whereas the other countries had areas with different incidence. Densely populated areas, such as major cities, had the lowest incidence. CONCLUSION: The incidence of T1D differed between the Nordic countries and also between the neighboring countries and generally decreased with population density. This indicates that environmental factors may contribute to the level of incidence of T1D.

International benchmarking in type 1 diabetes: Large difference in childhood HbA1c between eight high-income countries but similar rise during adolescence-A quality registry study.

OBJECTIVES: To identify differences and similarities in HbA1c levels and patterns regarding age and gender in eight high-income countries. SUBJECTS: 66 071 children and adolescents below18 years of age with type 1 diabetes for at least 3 months and at least one HbA1c measurement during the study period. METHODS: Pediatric Diabetes Quality Registry data from Austria, Denmark, England, Germany, Norway, Sweden, the United States, and Wales were collected between 2013 and 2014. HbA1c, gender, age, and duration were used in the analysis. RESULTS: Distribution of gender and age groups was similar in the eight participating countries. The mean HbA1c varied from 60 to 73 mmol/mol (7.6%-8.8%) between the countries. The increase in HbA1c between the youngest (0-9 years) to the oldest (15-17 years) age group was close to 8 mmol/mol (0.7%) in all countries (P < .001). Females had a 1 mmol/mol (0.1%) higher mean HbA1c than boys (P < .001) in seven out of eight countries. CONCLUSIONS: In spite of large differences in the mean HbA1c between countries, a remarkable similarity in the increase of HbA1c from childhood to adolescence was found.