Complete remission in children and adolescents with type 1 diabetes mellitus-prevalence and factors.

Little is known about complete remission in Type 1 diabetes mellitus (T1D) with the discontinuance of insulin treatment for a period of time. In this retrospective study we analysed the frequency and factors of onset and duration of 1. remission and 2. complete remission in children and adolescents with T1D from the Children Diabetes Centre in Bratislava, Slovakia. A total of 529 individuals with T1D, aged < 19 years (8.5 ± 4.3 years) at diabetes onset were included in the study. Remission was defined by HbA1c < 7.0% (53 mmol/mol) and an insulin daily dose < 0.5 IU/kg (and 0 IU/kg for complete remission). Remission occurred in 210 (39.7%) participants, and 15 of them had complete remission (2.8% from all participants). We have identified a new independent factor of complete remission onset (higher C-peptide). Complete remitters had a longer duration of remission compared with other remitters and also differed in lower HbA1c levels. No association was seen with autoantibodies or genetic risk score for T1D. Thus, not only partial but also complete remission is influenced by factors pointing toward an early diagnosis of T1D, which is important for better patient outcome.

The Bright Side of Skin Autofluorescence Determination in Children and Adolescents with Newly Diagnosed Type 1 Diabetes Mellitus: A Potential Predictor of Remission?

Skin autofluorescence (SAF) is a noninvasive method reflecting tissue accumulation of advanced glycation end products (AGEs). We investigated whether, in newly diagnosed children and adolescents with type 1 diabetes (T1D), this surrogate marker of long-term glycemia is associated with markers of the early manifestation phase, residual secretion capacity of the ß-cells, and the occurrence of remission. SAF was measured in 114 children and adolescents (age: 8.0 ± 4.5 years, 44% girls) at the time of T1D diagnosis, and related to HbA1c, C-peptide, diabetic ketoacidosis, and remission. 56 patients were followed up for 1 year. Seventy-four sex- and age-matched healthy individuals served as controls. SAF was higher in the T1D group compared with controls (1.0 ± 0.2 vs. 0.9 ± 0.2, p < 0.001). At the time of diagnosis, SAF correlated with HbA1c (r = 0.285, p = 0.002), was similar in patients with and without ketoacidosis, and was lower in the remitters compared with non-remitters (0.95 ± 0.18 vs. 1.04 ± 0.26, p = 0.027). Unlike HbA1c, SAF was an independent predictor of remission (∆R2 = 0.051, p = 0.004). Former studies consider SAF in diabetic patients as a tool to identify individuals at an increased risk of chronic complications. Here we show that determination of SAF at the time of T1D diagnosis might potentially predict remission, at least in children.

Comparison of diabetes phenotype in children and their mothers with permanent neonatal diabetes mellitus carrying the same KCNJ11 variants.

Objective. Mutations of the KCNJ11 gene are the most common cause of the permanent neonatal diabetes mellitus (PNDM). Majority of people with KNCJ11-PNDM have a de-novo mutation. We aimed to compare diabetes phenotype in two children and their mothers with PNDM carrying the same sulfonylurea-sensitive KCNJ11 variants.Methods. We have compared glibenclamide (sulfonylurea) dose, C-peptide, and HbA1c serum levels in two children and their mothers with PNDM up to 5.5-year follow-up. All of them were carrying a heterozygous activating KCNJ11 pathogenic variant (p.R201H in Family 1 or p.H46Y in Family 2). The mothers were initially treated with insulin and successfully switched to sulfonylurea at the age of 24 and 11 years, respectively. Both children were treated with sulfonylurea since the diagnosis of PNDM.Results. Glibenclamide dose was similar in both children (0.02-0.03 mg/kg/day), but lower compared to their mothers (0.1-0.4 mg/kg/day) (p<0.002). Fasting serum C-peptide levels were also lower in children (70-210 pmol/l) than in their mothers (263-720 pmol/l) (p<0.002), but no significant differences were observed in postprandial C-peptide levels. HbA1c was lower only in the son of SVK4 (Family 2) compared to his mother, as she had poor adherence to the sulfonylurea therapy during the first years after the sulfonylurea switch.Conclusions. Evaluation of the treatment in people with sulfonylurea-sensitive KNCJ11-PNDM should respect the age of patients together with the type of mutation and duration of diabetes at therapy start and may differ within one family.

Polymorphisms in the genes encoding TGF-beta1, TNF-alpha, and IL-6 show association with type 1 diabetes mellitus in the Slovak population.

Numerous cytokines have been shown to participate in the pathogenesis of type 1 diabetes (T1D). As gene polymorphisms can influence cytokine production or function, they may potentially contribute to genetic predisposition to the disease. The aim of this study was therefore to investigate the role of 22 single nucleotide polymorphisms (SNPs) in 13 cytokine and cytokine receptor genes in genetic susceptibility to T1D. Polymerase chain reaction with sequence-specific primers was used to genotype cytokine SNPs and HLA-DRB1 alleles in 151 diabetics and 140 healthy individuals of Slovak origin. Univariate analysis showed that transforming growth factor (TGF)-beta1 codon 10 TT homozygotes were significantly more susceptible to developing T1D than C allele carriers (P (c) = 0.0066, OR = 2.46). Furthermore, tumor necrosis factor (TNF)-alpha -308 A allele carriers were also significantly overrepresented among the diabetics (P (c) = 0.0031, OR = 2.62); however, the association of the -308 A allele with T1D might be due to its strong linkage disequilibrium with the susceptibility allele HLA-DRB1*0301. An association was also found with interleukin (IL)-6 -174 G/C and nt565 G/A SNPs; however, its significance was lost when statistical correction was applied. These data suggest that the TGF-beta1 codon 10 SNP is among numerous genetic variations with small individual effects on T1D development. Moreover, a possible role of TNF-alpha and IL-6 SNPs cannot be ruled out, although their association with T1D was due to strong LD with the HLA class II susceptibility allele or did not withstand statistical correction, respectively.

Severe insulin resistance and intrauterine growth deficiency associated with haploinsufficiency for INSR and CHN2: new insights into synergistic pathways involved in growth and metabolism.

OBJECTIVE: Digenic causes of human disease are rarely reported. Insulin via its receptor, which is encoded by INSR, plays a key role in both metabolic and growth signaling pathways. Heterozygous INSR mutations are the most common cause of monogenic insulin resistance. However, growth retardation is only reported with homozygous or compound heterozygous mutations. We describe a novel translocation [t(7,19)(p15.2;p13.2)] cosegregating with insulin resistance and pre- and postnatal growth deficiency. Chromosome translocations present a unique opportunity to identify modifying loci; therefore, our objective was to determine the mutational mechanism resulting in this complex phenotype. RESEARCH DESIGN AND METHODS: Breakpoint mapping was performed by fluorescence in situ hybridization (FISH) on patient chromosomes. Sequencing and gene expression studies of disrupted and adjacent genes were performed on patient-derived tissues. RESULTS Affected individuals had increased insulin, C-peptide, insulin-to-C-peptide ratio, and adiponectin levels consistent with an insulin receptoropathy. FISH mapping established that the translocation breakpoints disrupt INSR on chromosome 19p15.2 and CHN2 on chromosome 7p13.2. Sequencing demonstrated INSR haploinsufficiency accounting for elevated insulin levels and dysglycemia. CHN2 encoding beta-2 chimerin was shown to be expressed in insulin-sensitive tissues, and its disruption was shown to result in decreased gene expression in patient-derived adipose tissue. CONCLUSIONS: We present a likely digenic cause of insulin resistance and growth deficiency resulting from the combined heterozygous disruption of INSR and CHN2, implicating CHN2 for the first time as a key element of proximal insulin signaling in vivo.

Glycation and lipid peroxidation in children and adolescents with type 1 diabetes mellitus with and without diabetic complications.

Glycation and oxidative stress lead to formation of compounds that have several biological effects and contribute to the development of the complications of diabetes mellitus. All steps of glycoxidation generate oxygen free radicals, some of them in common with lipid peroxidation pathways. Some oxidation or lipid peroxidation products may bind to proteins and amplify glycoxidation-generated lesions. The aim of this study was to measure glycation and lipid peroxidation parameters and examine the relationship between them in patients with type 1 diabetes mellitus (DM1) with (+DC) and without (-DC) diabetic complications. Fifty patients with DM1 aged from 7-19 years and with duration of DM1 (DD) at least 5 years were included. Twenty-four patients were -DC and 26 were +DC. Twelve healthy children formed a control group. There were significantly higher values of fructosamine (FAM), HbA(1c), serum advanced glycation endproducts (s-AGEs) and lipid peroxides (LPO) in the +DC group compared with -DC, and significantly higher values of HbA(1c), FAM and LPO in both diabetic groups than in controls. The s-AGEs level in the -DC group was similar to that in controls. In the total diabetic group, regardless of DC, there was a significant negative correlation between LPO and HDL-C (r = -0.379; p <0.05), and a positive correlation between LPO and triacylglycerol (TAG) (r = 0.852; p <<0.05), FAM (r = 0.414; p <0.05) and s-AGEs (r = 0.454; p <0.05). In the +DC group LPO correlated negatively with HDL-C (r = -0.392, p <0.05) and positively with TAG (r = 0.848; p <<0.05), FAM (r = 0.457; p = 0.02), and s-AGEs (r = 0.516, p = 0.02), whereas in the -DC group LPO correlated only with HDL-C (r = -0.441; p = 0.03) and TAG (r = 0.769; p <<0.05). We demonstrated a linkage between enhanced formation of AGEs and lipid peroxidation products and the presence of diabetic complications. Thus, the overproduction of glycation and lipid peroxidation products may take part in DC development as early as in childhood and adolescence.

HbA1c and serum levels of advanced glycation and oxidation protein products in poorly and well controlled children and adolescents with type 1 diabetes mellitus.

Diabetes mellitus is associated with hyperglycemia and with accelerated non-enzymatic glycation, increased oxidative stress and free radical production. The aim of the present study was to evaluate the levels of proteins glycation and oxidation parameters, compare them between poorly and well controlled children with type 1 diabetes mellitus, and determine the impact of glycemic control on these parameters. Blood and serum were obtained from 81 patients with type 1 diabetes mellitus (DM1) (20 patients had long-term good glycemic control [GGC], 61 patients had long-term poor glycemic control [PGC]). Thirty-one healthy children were used as controls. Fructosamine (FAM) was determined by a spectrophotometric method, HbA1c was measured by LPLC, serum advanced glycation end-products (s-AGEs) were determined fluorimetrically, and advanced oxidation protein products (AOPP) were measured spectrophotometrically. We observed significantly higher FAM, HbA1c, s-AGEs and AOPP levels in the patients with DM1 compared with controls, and significantly higher FAM, HbA1c and sAGEs levels in the PGC group compared with the GGC group. AOPP was higher in the PGC group than in the GGC group, but not significantly. In the PGC group we observed significant correlations between HbA1c and HDL-C (r = -0.306, p = 0.01), HbA1c and s-AGEs (r = 0.486, p < 0.001), and HbA1c and AOPP (r = 0.447, p < 0.01). s-AGEs significantly correlated with triacylglycerols (TAG) (r = 0.537, p < 0.001) and AOPP with HDL-C (r = -0.336, p < 0.05), TAG (r = 0.739, p < 0.001) and s-AGEs (r = 0.577, p < 0.001). In conclusion, our results showed both glycative and oxidative stress are increased in the PGC diabetic group compared with controls, they are linked with glycemic control, and probably contribute to the development of diabetic complications. We suggest that the measurement of not only HbA1c but also s-AGEs and AOPP may be useful to predict the risk of development of diabetic complications.

Identification of a novel beta-cell glucokinase (GCK) promoter mutation (-71G>C) that modulates GCK gene expression through loss of allele-specific Sp1 binding causing mild fasting hyperglycemia in humans.

OBJECTIVE: Inactivating mutations in glucokinase (GCK) cause mild fasting hyperglycemia. Identification of a GCK mutation has implications for treatment and prognosis; therefore, it is important to identify these individuals. A significant number of patients have a phenotype suggesting a defect in glucokinase but no abnormality of GCK. We hypothesized that the GCK beta-cell promoter region, which currently is not routinely screened, could contain pathogenic mutations; therefore, we sequenced this region in 60 such probands. RESEARCH DESIGN AND METHODS: The beta-cell GCK promoter was sequenced in patient DNA. The effect of the identified novel mutation on GCK promoter activity was assessed using a luciferase reporter gene expression system. Electrophoretic mobility shift assays (EMSAs) were used to determine the impact of the mutation on Sp1 binding. RESULTS: A novel -71G>C mutation was identified in a nonconserved region of the human promoter sequence in six apparently unrelated probands. Family testing established cosegregation with fasting hyperglycemia (> or = 5.5 mmol/l) in 39 affected individuals. Haplotype analysis in the U.K. family and four of the Slovakian families demonstrated that the mutation had arisen independently. The mutation maps to a potential transcriptional activator binding site for Sp1. Reporter assays demonstrated that the mutation reduces promoter activity by up to fourfold. EMSAs demonstrated a dramatic reduction in Sp1 binding to the promoter sequence corresponding to the mutant allele. CONCLUSIONS: A novel beta-cell GCK promoter mutation was identified that significantly reduces gene expression in vitro through loss of regulation by Sp1. To ensure correct diagnosis of potential GCK-MODY (maturity-onset diabetes of the young) cases, analysis of the beta-cell GCK promoter should be included.

Improved glycemic control through continuous glucose sensor-augmented insulin pump therapy: prospective results from a community and academic practice patient registry.

BACKGROUND: Conducted by highly experienced investigators with abundant time and resources, phase III studies of continuous glucose sensing (CGS) may lack generalizability to everyday clinical practice. METHOD: Community or academic practices in six Central and Eastern European or Mediterranean countries prospectively established an anonymized registry of consecutive patients with type 1 insulin-dependent diabetes mellitus starting CGS-augmented insulin pump therapy with the Paradigm X22 (Medtronic MiniMed, Northridge, CA) under everyday conditions, without prior CGS with another device. We compared glycosylated hemoglobin (GHb) values before and after 3 months of CGS and assessed relationships between insulin therapy variables and glycemia-related variables at weeks 1, 4, and 12 of CGS. RESULTS: Of 102 enrolled patients, 85 (83%) with complete weeks 1, 4, and 12 sensor data and baseline/3-month GHb data were evaluable. Evaluable patients were approximately 54% male and approximately 75% adult (mean age, 33.2 +/- 16.9 years) with longstanding diabetes and high personal/family education levels. Mean GHb declined significantly after 3 months of CGS (7.55 +/- 1.33% at baseline to 6.81 +/- 1.08% after 12 weeks, 0.74% absolute decrease, P < 0.001). The absolute GHb reduction correlated significantly (P < 0.0005) with baseline GHb: larger absolute reductions tended to occur when baseline levels were higher. An increased basal insulin dose as a percentage of the total daily insulin dose and a decreased daily bolus count from week 1 to week 12 of CGS predicted GHb improvement from baseline to week 12. CONCLUSIONS: CGS-augmented insulin pump therapy appears to improve glycemic control in type 1 diabetes in varied everyday practice settings.

CTLA-4 gene polymorphisms predispose to autoimmune endocrinopathies but not to celiac disease.

OBJECTIVES: The aim of the study was to determine the association of two CTLA-4 gene polymorphisms (CT60, +49 A/G) with Hashimoto thyroiditis (HT), type 1 diabetes mellitus (T1DM) and celiac disease (CD) as well as with the occurrence of multi-organ involvement by autoimmunity in children. METHODS: Genotyping was done by RFLP analysis in Slovak children with HT (n=63) and CD (n=120) and both Slovak and Slovene children with T1DM (n=320) and healthy controls (n=231). RESULTS: We found a significant association of the G allele of the CT60 polymorphism with HT (p<0,0005) in the Slovak population and T1DM in both Slovak (p<0.01) and Slovene populations (p<0.005). The G allele of the +49A/G polymorphism was significantly, though less strongly, associated with T1DM (p<0.05) and HT (p<0.05). Distribution of genotypes of CTLA-4 gene polymorphisms in CD patients did not differ significantly from controls. None of the polymorphisms was associated with multi-organ involvement by autoimmunity. CONCLUSION: The G allele of both examined CTLA-4 gene polymorphisms predisposes to HT and T1DM, but not to CD. No association with multi-organ involvement was found. The GG genotype of the CT60 polymorphism may identify CD patients at an increased risk for concomitant T1DM and HT. Further studies to assess the predictive value of CTLA-4 polymorphisms for the co-occurrence of HT and T1DM in CD patients are needed.

Prevalence of permanent neonatal diabetes in Slovakia and successful replacement of insulin with sulfonylurea therapy in KCNJ11 and ABCC8 mutation carriers.

CONTEXT: Mutations in the KCNJ11 and ABCC8 genes encoding the pancreatic beta-cell K(ATP) channel have recently been shown to be the most common cause of permanent neonatal diabetes mellitus (PNDM). Information regarding the frequency of PNDM has been based mainly on nonpopulation or short-term collections only. Thus, the aim of this study was to identify the incidence of PNDM in Slovakia and to switch patients to sulfonylurea (SU) where applicable. DESIGN: We searched for PNDM patients in the Slovak Children Diabetes Registry. In insulin-treated patients who matched the clinical criteria for PNDM, the KCNJ11 or ABCC8 genes were sequenced, and mutation carriers were invited for replacement of insulin with SU. RESULTS: Eight patients with diabetes onset before the sixth month of life without remission were identified since 1981, which corresponds to the PNDM incidence in Slovakia of one case in 215,417 live births. In four patients, three different KCNJ11 mutations were found (R201H, H46Y, and L164P). Three patients with the KCNJ11 mutations (R201H and H46Y) were switched from insulin to SU, decreasing their glycosylated hemoglobin from 9.3-11.0% on insulin to 5.7-6.6% on SU treatment. One patient has a novel V86A mutation in the ABCC8 gene and was also substituted with SU. CONCLUSIONS: PNDM frequency in Slovakia is much higher (one in 215,417 live births) than previously suggested from international estimates (about one in 800,000). We identified one ABCC8 and four KCNJ11 mutation carriers, of whom four were successfully transferred to SU, dramatically improving their diabetes control and quality of life.