The genetic and regulatory architecture of ERBB3-type 1 diabetes susceptibility locus

in Molecular and Cellular Endocrinology (2016), 419

The study aimed to explore the role of ERBB3 in type 1 diabetes (T1D). We examined whether genetic variation of ERBB3 (rs2292239) affects residual β-cell function in T1D cases. Furthermore, we examined ... [more ▼]

The study aimed to explore the role of ERBB3 in type 1 diabetes (T1D). We examined whether genetic variation of ERBB3 (rs2292239) affects residual β-cell function in T1D cases. Furthermore, we examined the expression of ERBB3 in human islets, the effect of ERBB3 knockdown on apoptosis in insulin-producing INS-1E cells and the genetic and regulatory architecture of the ERBB3 locus to provide insights to how rs2292239 may confer disease susceptibility. rs2292239 strongly correlated with residual β-cell function and metabolic control in children with T1D. ERBB3 locus associated lncRNA (NONHSAG011351) was found to be expressed in human islets. ERBB3 was expressed and down-regulated by pro-inflammatory cytokines in human islets and INS-1E cells; knockdown of ERBB3 in INS-1E cells decreased basal and cytokine-induced apoptosis. Our data suggests an important functional role of ERBB3 and its potential regulators in the β-cells and may constitute novel targets to prevent β-cell destruction in T1D. © 2015 Elsevier Ireland Ltd. [less ▲]

Lessons from the Hvidoere International Study Group on childhood diabetes: Be dogmatic about outcome and flexible in approach

in Pediatric Diabetes (2013), 14(7), 473-480

[No abstract available]

Trends in childhood type 1 diabetes incidence in Europe during 1989-2008: evidence of non-uniformity over time in rates of increase

in Diabetologia (2012), 55(8), 2142-2147

Aims/hypothesis The aim of the study was to describe 20- year incidence trends for childhood type 1 diabetes in 23 EURODIAB centres and compare rates of increase in the first (1989–1998) and second ... [more ▼]

Aims/hypothesis The aim of the study was to describe 20- year incidence trends for childhood type 1 diabetes in 23 EURODIAB centres and compare rates of increase in the first (1989–1998) and second (1999–2008) halves of the period. Methods All registers operate in geographically defined regions and are based on a clinical diagnosis. Completeness of registration is assessed by capture–recapture methodology. Twenty-three centres in 19 countries registered 49,969 new cases of type 1 diabetes in individuals diagnosed before their 15th birthday during the period studied. Results Ascertainment exceeded 90% in most registers. During the 20-year period, all but one register showed statistically significant changes in incidence, with rates universally increasing. When estimated separately for the first and second halves of the period, the median rates of increase were similar: 3.4% per annum and 3.3% per annum, respectively. However, rates of increase differed significantly between the first half and the second half for nine of the 21 registers with adequate coverage of both periods; five registers showed significantly higher rates of increase in the first half, and four significantly higher rates in the second half. Conclusions/interpretation The incidence rate of childhood type 1 diabetes continues to rise across Europe by an average of approximately 3–4% per annum, but the increase is not necessarily uniform, showing periods of less rapid and more rapid increase in incidence in some registers. This pattern of change suggests that important risk exposures differ over time in different European countries. Further time trend analysis and comparison of the patterns in defined regions is warranted. [less ▲]

Disease progression and search for monogenic diabetes among children with new onset type 1 diabetes negative for ICA, GAD- and IA-2 Antibodies

in BMC Endocrine Disorders (2010), 10

Background: To investigate disease progression the first 12 months after diagnosis in children with type 1 diabetes negative (AAB negative) for pancreatic autoantibodies [islet cell autoantibodies(ICA ... [more ▼]

Background: To investigate disease progression the first 12 months after diagnosis in children with type 1 diabetes negative (AAB negative) for pancreatic autoantibodies [islet cell autoantibodies(ICA), glutamic acid decarboxylase antibodies (GADA) and insulinoma-associated antigen-2 antibodies (IA-2A)]. Furthermore the study aimed at determining whether mutations in KCNJ11, ABCC8, HNF1A, HNF4A or INS are common in AAB negative diabetes.Materials and methods: In 261 newly diagnosed children with type 1 diabetes, we measured residual β-cell function, ICA, GADA, and IA-2A at 1, 6 and 12 months after diagnosis. The genes KCNJ11, ABCC8, HNF1A, HNF4A and INS were sequenced in subjects AAB negative at diagnosis. We expressed recombinant K-ATP channels in Xenopus oocytes to analyse the functional effects of an ABCC8 mutation.Results: Twenty-four patients (9.1%) tested AAB negative after one month. Patients, who were AAB-negative throughout the 12-month period, had higher residual β-cell function (P = 0.002), lower blood glucose (P = 0.004), received less insulin (P = 0.05) and had lower HbA1c(P = 0.02) 12 months after diagnosis. One patient had a heterozygous mutation leading to the substitution of arginine at residue 1530 of SUR1 (ABCC8) by cysteine. Functional analyses of recombinant K-ATP channels showed that R1530C markedly reduced the sensitivity of the K-ATP channel to inhibition by MgATP. Morover, the channel was highly sensitive to sulphonylureas. However, there was no effect of sulfonylurea treatment after four weeks on 1.0-1.2 mg/kg/24 h glibenclamide.Conclusion: GAD, IA-2A, and ICA negative children with new onset type 1 diabetes have slower disease progression as assessed by residual beta-cell function and improved glycemic control 12 months after diagnosis. One out of 24 had a mutation in ABCC8, suggesting that screening of ABCC8 should be considered in patients with AAB negative type 1 diabetes. © 2010 Pörksen et al; licensee BioMed Central Ltd. [less ▲]

Associations between physical activity, sedentary behavior, and glycemic control in a large cohort of adolescents with type 1 diabetes: The Hvidoere Study Group on Childhood Diabetes

in Pediatric Diabetes (2009), 10(4), 234-239

Background: The Hvidoere Study Group on Childhood Diabetes has demonstrated persistent differences in metabolic outcomes between pediatric diabetes centers. These differences cannot be accounted for by ... [more ▼]

Background: The Hvidoere Study Group on Childhood Diabetes has demonstrated persistent differences in metabolic outcomes between pediatric diabetes centers. These differences cannot be accounted for by differences in demographic, medical, or treatment variables. Therefore, we sought to explore whether differences in physical activity or sedentary behavior could explain the variation in metabolic outcomes between centers. Methods: An observational cross-sectional international study in 21 centers, with demographic and clinical data obtained by questionnaire from participants. Hemoglobin A1c (HbA1c) levels were assayed in one central laboratory. All individuals with diabetes aged 11-18 yr (49.4% female), with duration of diabetes of at least 1 yr, were invited to participate. Individuals completed a self-reported measure of quality of life (Diabetes Quality of Life - Short Form [DQOL-SF]), with well-being and leisure time activity assessed using measures developed by Health Behaviour in School Children WHO Project. Results: Older participants (p < 0.001) and females (p < 0.001) reported less physical activity. Physical activity was associated with positive health perception (p < 0.001) but not with glycemic control, body mass index, frequency of hypoglycemia, or diabetic ketoacidosis. The more time spent on the computer (r = 0.06; p < 0.05) and less time spent doing school homework (r = -0.09; p < 0.001) were associated with higher HbA1c. Between centers, there were significant differences in reported physical activity (p < 0.001) and sedentary behavior (p < 0.001), but these differences did not account for center differences in metabolic control. Conclusions: Physical activityis strongly associated with psychological well-being but has weak associations with metabolic control. Leisure time activity is associated with individual differences in HbA1c but not with intercenter differences. © 2009 John Wiley & Sons A/S. [less ▲]

Are family factors universally related to metabolic outcomes in adolescents with type 1 diabetes?

in Diabetic Medicine: A Journal of the British Diabetic Association (2008), 25(4), 463-468

Aims: To assess the importance of family factors in determining metabolic outcomes in adolescents with Type 1 diabetes in 19 countries. Methods: Adolescents with Type 1 diabetes aged 11-18 years, from 21 ... [more ▼]

Aims: To assess the importance of family factors in determining metabolic outcomes in adolescents with Type 1 diabetes in 19 countries. Methods: Adolescents with Type 1 diabetes aged 11-18 years, from 21 paediatric diabetes care centres, in 19 countries, and their parents were invited to participate. Questionnaires were administered recording demographic data, details of insulin regimens, severe hypoglycaemic events and number of episodes of diabetic ketoacidosis. Adolescents completed the parental involvement scale from the Diabetes Quality of Life for Youth - Short Form (DQOLY-SF) and the Diabetes Family Responsibility Questionnaire (DFRQ). Parents completed the DFRQ and a Parental Burden of Diabetes score. Glycated haemoglobin (HbA1c) was analysed centrally on capillary blood. Results: A total of 2062 adolescents completed a questionnaire, with 2036 providing a blood sample; 1994 parents also completed a questionnaire. Family demographic factors that were associated with metabolic outcomes included: parents living together (t = 4.1; P < 0.001), paternal employment status (F = 7.2; d.f. = 3; P < 0.001), parents perceived to be over-involved in diabetes care (r = 0.11; P < 0.001) and adolescent-parent disagreement on responsibility for diabetes care practices (F = 8.46; d.f. = 2; P < 0.001). Although these factors differed between centres, they did not account for centre differences in metabolic outcomes, but were stronger predictors of metabolic control than age, gender or insulin treatment regimen. Conclusions: Family factors, particularly dynamic and communication factors such as parental over-involvement and adolescent-parent concordance on responsibility for diabetes care appear be important determinants of metabolic outcomes in adolescents with diabetes. However, family dynamic factors do not account for the substantial differences in metabolic outcomes between centres. © 2008 The Authors. [less ▲]