Are glucose and insulin levels at all time points during OGTT a reliable marker of diabetes mellitus risk in pediatric obesity?

PURPOSE: Childhood overweight and obesity associated with insulin resistance and metabolic syndrome represent the new global pandemic and the main causative factors for dysglycemia, prediabetes, and Type 2 Diabetes Mellitus (T2DM). Predictors, such as HOMA-IR, HOMA-ß%, and QUICKI lack specific reference values in children. OGTT is a gold standard for glycometabolic assessment. Recently, a glycemic level higher than 155 mg/dl at + 60' after glucose ingestion has been defined as a risk factor for T2DM in obese adolescents. We aim to analyze and correlate fasting insulin-resistance markers with OGTT results in overweight/obese children and adolescents. METHODS: We retrospectively evaluated glucose and insulin values during a 2-h OGTT every 30 min in 236 overweight/obese patients. Glucose values and insulin sum during OGTT were compared to glycometabolic indexes and different cut-off values for insulin sum. RESULTS: A 1-h glucose > 155 mg/dl and insulin sum > 535 microU/ml at all times during OGTT are the best predictors of diabetes risk in obese youths. A1-h glucose > 155 mg/dl is significantly associated with HbA1c > 5.7%, while no association was observed between HbA1c > 5.7% and glucose levels at baseline and 2 h. The ability of the standardized HOMA-IR to predict the prediabetes status is clearly lower than the total insulin sum at OGTT. CONCLUSION: Our study demonstrates that also 1-h post-OGTT glucose, together with HbA1c, is an effective diabetes predictor.

Glucokinase mutations in pediatric patients with impaired fasting glucose.

AIMS: Our aim was to detect the frequency of glucokinase (GCK) gene mutations in a cohort of patients with impaired fasting glucose and to describe the clinical manifestations of identified variants. We also aimed at predicting the effect of the novel missense mutations by computational approach. METHODS: Overall 100 unrelated Italian families with impaired fasting glucose were enrolled and subdivided into two cohorts according to strict and to mild criteria for diagnosis of maturity-onset diabetes of the young (MODY). GCK gene sequencing was performed in all participants. RESULTS: Fifty-three Italian families with 44 different mutations affecting the GCK and co-segregating with the clinical phenotype of GCK/MODY were identified. All mutations were in heterozygous state. In Sample 1, GCK defects were found in 32/36 (88.9%) subjects selected with strict MODY diagnostic criteria, while in Sample 2 GCK defects were found in 21/64 (32.8%) subjects selected with mild MODY diagnostic criteria. CONCLUSIONS: Our study enlarged the wide spectrum of GCK defects by adding 9 novel variants. The application of strict recruitment criteria resulted in 88.9% incidence of GCK/MODY, which confirmed it as the commonest form of MODY in the Italian population. In order to avoid misdiagnosis of GCK/MODY, it could be useful to perform molecular screening even if one or more clinical parameters for the diagnosis of MODY are missing. Computational analysis is useful to understand the effect of GCK defect on protein functionality, especially when the novel identified variant is a missense mutation and/or parents' DNA is not available.

Insulin pump failures in Italian children with Type 1 diabetes: retrospective 1-year cohort study.

AIMS: Insulin pump failure and/or malfunction requiring replacement have not been thoroughly investigated. This study evaluated pump replacement in children and adolescents with Type 1 diabetes using insulin pump therapy. METHODS: Data were collected for all participants younger than 19 years, starting insulin pump therapy before 31 December 2013. For each child, age, disease duration, date of insulin pump therapy initiation, insulin pump model, failure/malfunction/replacement yes/no and reason were considered for the year 2013. RESULTS: Data were returned by 40 of 43 paediatric centres belonging to the Diabetes Study Group of the Italian Society of Paediatric Endocrinology and Diabetology. In total, 1574 of 11 311 (13.9%) children and adolescents with Type 1 diabetes were using an insulin pump: 29.2% Animas VIBE™ , 9.4% Medtronic MiniMed 715/515™ , 34.3% Medtronic MiniMed VEO™ , 24.3% Accu-Check Spirit Combo™ and 2.8% other models. In 2013, 0.165 insulin pump replacements per patient-year (11.8% due to pump failure/malfunction and 4.7% due to accidental damage) were recorded. Animas VIBE™ (22.1%) and Medtronic MiniMed VEO™ (17.7%) were the most replaced. CONCLUSIONS: In a large cohort of Italian children and adolescents with Type 1 diabetes, insulin pump failure/malfunction and consequent replacement are aligned with rates previously reported and higher in more sophisticated pump models.

Type 1 diabetes mellitus and asthma: A follow-up study

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Retinopathy screening in patients with type 1 diabetes diagnosed in young age using a non-mydriatic digital stereoscopic retinal imaging.

BACKGROUND: Diabetic retinopathy seriously impairs patients' quality of life, since it represents the first cause of blindness in industrialized countries. AIM: To estimate prevalence of retinopathy in young Type 1 diabetes patients using a non-mydriatic digital stereoscopic retinal imaging (NMDSRI), and to evaluate the impact of socio-demographic, clinical, and metabolic variables. SUBJECTS AND METHODS: In 247 young patients glycated hemoglobin (HbA1c), gender, age, pubertal stage, presence of diabetic ketoacidosis (DKA), HLA-DQ heterodimers of susceptibility for Type 1 diabetes, and ß-cell autoimmunity at clinical onset were considered. At retinopathy screening, we evaluated age, disease duration, pubertal stage, body mass index (BMI-SDS), insulin requirement, HbA1c levels, other autoimmune diseases, diabetes-related complications, serum concentrations of cholesterol and triglycerides, systolic and diastolic blood pressure. RESULTS: Retinopathy was found in 26/247 patients: 25 showed background retinopathy, and 1 had a sight-threatening retinopathy. A significant relationship between retinopathy and female gender (p=0.01), duration of disease ≥15 yr (p<0.0001), serum triglycerides levels >65 mg/dl (p=0.012) and mean HbA1c ≥7.5% or >9% (p=0.0014) were found at the multivariate logistic analysis. CONCLUSIONS: Metabolic control is the most important modifiable factor and promotion of continuous educational process to reach a good metabolic control is a cornerstone to prevent microangiopathic complications. Symptoms appear when the complication is already established; a screening program with an early diagnosis is mandatory to prevent an irreversible damage.

Type 1 diabetes and measles, mumps and rubella childhood infections within the Italian Insulin-dependent Diabetes Registry.

AIMS: Several studies confirmed the growing rate of Type 1 diabetes mellitus in childhood coinciding with increasing diagnosis of viral infections. A study investigating the incidence of Type 1 diabetes during 1996-1997 showed a higher notification of viral infections in the Pavia District. The aim was to confirm these results. METHODS: This study evaluated the relationship between new cases of Type 1 diabetes and those of measles, mumps and rubella in 1996-2001, analysing data of newly-diagnosed Type 1 diabetes children, aged 0-14 years and enrolled into the RIDI (Italian Insulin-dependent Diabetes Registry) during the same years. Measles, rubella and mumps rates were calculated using as denominator the estimated 'population at risk', represented by the number of 0- to 14 year-old subjects who did not undergo the MMR (measles, mumps and rubella) vaccination. In order to investigate the association between Type 1 diabetes incidence and measles, rubella and mumps respectively, Spearman's rank correlation was used. RESULTS: The analysis of the whole Registries data did not at first show any statistical significance between age-standardized Type 1 diabetes incidence density and estimated rates of measles, mumps and rubella notifications. Excluding data from Sardinia Registry, a significant association was observed between Type 1 diabetes incidence and mumps (P = 0.034) and rubella (P = 0.014), respectively, while there was no statistical significance between the incidence of measles cases and diabetes rates (P = 0.269). CONCLUSIONS: According to our findings, mumps and rubella viral infections are associated with the onset of Type 1 diabetes. The statistical significance observed after exclusion of the Sardinian data suggests that other environmental factors may operate over populations with different genetic susceptibility.

A novel hepatocyte nuclear factor-1ß (MODY 5) gene mutation in a Romanian boy with pancreatic calcifications, renal and hepatic dysfunction.

We report a 12-years-old Romanian boy with a diagnosis of diabetes and renal insufficiency. Mutations in homeodomain-containing transcription factor hepatocyte nuclear factor (HNF-1ß) have been reported in association with maturity-onset diabetes of the young (MODY 5) and early maturity-onset diabetes, progressive non-diabetic renal dysfunction and bilateral renal cysts. We found a new heterozygous mutation in HFN-1ß located in the exon 3 (c.715 G>C; p.239R) associated to pancreatic calcifications. The importance of molecular diagnosis of MODY patients is reinforced and the need for a careful follow-up is stressed in order to monitor the progression of clinical manifestations and its correlation with the gene mutation.

Serum transforming growth factor ß1 during diabetes development in non-obese diabetic mice and humans.

Recent data show that regulatory cells with transforming growth factor (TGF)-ß1-dependent activity are able to restore self-tolerance in overtly diabetic non-obese diabetic (NOD) mice. Thus, TGF-ß1 seems to have a relevant role in protection from autoimmune diabetes. Our aim was to investigate the possible significance of serum TGF-ß1 measurement in the natural history of diabetes in NOD mice, as well as in children positive for at least one islet-related antibody. Serum TGF-ß1 (both total and active) was measured by enzyme-linked immunosorbent assay at monthly intervals in 26 NOD mice during the spontaneous development of diabetes and, on a yearly basis, in nine siblings of patients with type 1 diabetes (T1D) with a follow-up of 4 years. Diabetes appeared between the 12th week of age and the end of the study period (36 weeks) in 17 mice. TGF-ß1 serum level variations occurred in the prediabetic period in both NOD mice and humans and diabetes diagnosis followed a continuing reduction of active TGF-ß1 (aTGF-ß1) serum levels. In mice, aTGF-ß1 serum levels measured at 4 weeks of age correlated positively with severity of insulitis, and negatively with percentage of insulin-positive cells. Our findings suggest that in NOD mice serum TGF-ß1 levels during the natural history of the diabetes reflect the course of islet inflammation. The measurement of aTGF-ß1 in islet-related antibody-positive subjects may provide insights into the natural history of prediabetic phase of T1D.

Genetic investigation in an Italian child with an unusual association of atrial septal defect, attributable to a new familial GATA4 gene mutation, and neonatal diabetes due to pancreatic agenesis.

AIMS: Permanent neonatal diabetes is a rare condition affecting 1 in 300,000-400,000 live births; only in 60% of cases it is possible to identify the genetic defect. The condition of pancreatic agenesis is rarer still. Only two genes are known to determine this phenotype: PDX-1 and PTF1A. Congenital heart defects are among the most common developmental anomalies, affecting 1% of newborns, and the GATA4 gene is less frequently involved in these disorders. An Italian child with pancreatic agenesis and an atrial septal defect was genetically investigated to elucidate whether the association of the two pathologies was casual, or represented a new pancreatic/cardiac syndrome. METHODS: A panel of pancreas development genes, including GCK, Kir6.2, PTF1A, PDX-1, HNF-1A, NgN3, SOX17, SOX7, SOX9, INS, HNF1-B and SUR1 plus the GATA4 gene, were screened for characterization of pancreatic agenesis and cardiac defect. RESULTS: Screening for genes causing permanent neonatal diabetes was negative. A novel mutation in GATA4 (c1512C>T) was detected and functional characterization confirmed a reduced activity of the protein. In the family members, the GATA4 mutation co-segregates with a cardiac phenotype, but not with pancreatic agenesis. CONCLUSIONS: We describe the first report of pancretic agenesis with an associated cardiac defect and a mutation in the GATA4 gene. We could not establish that the GATA4 mutation was causative for pancreatic agenesis and further genetic investigation to detect the genetic cause of the pancreas agenesis was unsuccessful. We conclude that, the two pathologies are attributable to two independent events.

The osteopontin gene +1239A/C single nucleotide polymorphism is associated with type 1 diabetes mellitus in the Italian population.

Secreted phosphoprotein 1, also known as Osteopontin (Opn), is a proinflammatory cytokine involved in the TH1 response and is highly expressed in the islets and pancreatic lymph nodes of non-obese diabetic mice before the onset of diabetes. In humans, typing of the +1239A/C single nucleotide polymorphism (SNP) in the 3UTR of the Opn gene (SPP1) showed that +1239C carriers displayed higher Opn serum levels than +1239A homozygotes and a higher risk of developing autoimmune/lymphoproliferative syndrome, multiple sclerosis, and systemic lupus erythematosus. The aim of this work is to evaluate whether +1239A/C is also associated with type 1 diabetes mellitus (T1DM). We typed +1239A/C in an initial cohort of 184 T1DM patients and 361 controls, and confirmed our data in a second cohort of 513 patients and 857 controls. In both cohorts, +1239C carriers displayed a significantly higher risk of T1DM than +1239A homozygotes (combined cohorts: OR=1.63, 95 percent CI: 1.34-1.97). Clinical analysis did not detect any differences between patients carrying or not +1239C in terms of gender distribution and age at T1DM diagnosis. These data suggest that SPP1 variants marked by +1239C are associated with T1DM development in the Italian population. The predisposing effect may depend on its effect on Opn levels.

Estimation of genetic risk for Type 1 diabetes mellitus in newborns on dried blood spot.

BACKGROUND: The main contribution to genetic susceptibility for Type 1 Diabetes Mellitus (T1DM) is conferred by the Human Leukocyte Antigens (HLA). AIM: We evaluated the feasibility of large scale screening on Dried Blood Spot (DBS) to estimate the genetic risk for T1DM in newborns. SUBJECTS AND METHODS: Peripheral blood DBS samples from 256 newborns, were genotyped for HLA DRB1 and DQB1 alleles identification by a commercially available assay based on a dissociation enhancer lanthanide fluorescence system available in many newborn screening laboratories. Results were compared with those obtained in two wide multicentric studies on cord blood (DIABFIN and PREVEFIN). RESULTS: Genotyping on DBS revealed 6 subjects at high risk for T1DM, 99 at moderate risk for T1DM and the remaining at low risk for T1DM. We found 100% concordance between both techniques for HLA-DQB1 and DRB1 determination, confirming the feasibility of large scale screening on DBS. CONCLUSIONS: DBSs represent a resource for future studies about new genetics markers. This assay for estimate the genetic risk of T1DM on DBS showed an excellent sensitivity, specificity and accuracy compared with conventional techniques. Moreover, this assay resulted less expensive, and it could be easily performed on material already collected for newborn screening programs.

Folic acid, vitamin B12, and homocysteine levels during fasting and after methionine load in patients with Type 1 diabetes mellitus.

AIMS: To assess plasma concentrations of folic acid, vitamin B12, and total plasma homocysteine (tHCY) during fasting and after methionine load in young patients with Type 1 diabetes mellitus (T1DM). METHODS: We enrolled 41 young patients with T1DM without any sign of microvascular complications and 123 healthy controls in a 1:3 case-control study. Fasting and post-methionine load (PML) tHCY, folic acid, and vitamin B12 levels were measured in both groups. Data regarding chronological age, metabolic control (assessed by mean values of glycated hemoglobin in the last 12 months) and disease duration were also recorded. RESULTS: Fasting and PML tHCY levels were significantly lower in patients than in controls: 7.3+/-2.7 micromol/l vs 8.3+/-2.5 micromol/l (p=0.01), and 16.7+/-5.8 micromol/l vs 17.3+/-4.3 micromol/l (p=0.01), respectively. No correlation was found between fasting and PML tHCY levels and chronological age, disease duration, metabolic control, and insulin requirement. Patients had significantly higher vitamin B12 levels compared to controls: 767+/-318 pg/ml vs 628+/-236 pg/ml (p=0.003), while folic acid turned out to be lower in patients than in controls: 5.3+/-1.9 nmol/l vs 7.5+/-2.6 nmol/l (p<0.0001). CONCLUSIONS: Adolescents and young adults with T1DM without microvascular complications showed lower tHCY both during fasting and after methionine load. Lower folate concentrations in these patients might benefit from food fortification.

Serum Th1 (CXCL10) and Th2 (CCL2) chemokine levels in children with newly diagnosed Type 1 diabetes: a longitudinal study.

AIMS: Cell-mediated immunity and pro-inflammatory cytokines are implicated in the pathogenesis of Type 1 diabetes. The aim of this study was to investigate whether circulating chemokines involved in T-helper 1 (CXCL10) and T-helper 2 (CCL2) autoimmunity are increased in children with Type 1 diabetes at onset and follow-up. METHODS: Serum CXCL10 and CCL2 were measured in 96 children with newly diagnosed Type 1 diabetes, 59 age-matched first-degree relatives of diabetic children and 40 age-matched non-diabetic children with no family history of diabetes. In the diabetic children, an additional serum sample was obtained a median of 16 months after diagnosis. RESULTS: Serum CXCL10 levels were significantly higher in Type 1 children than in relatives or control children (P < 0.001); 44.7% of patients had a serum CXCL10 level >or= 2 standard deviation above the mean value of the control group vs. 3.4% of relatives (P < 0.0001). In contrast, serum CCL2 levels were similar in patients, relatives and control subjects. In the Type 1 diabetic patients at follow-up, CXCL10 was significantly reduced vs. baseline (P = 0.01), while CCL2 did not change. CONCLUSIONS: In children with newly diagnosed Type 1 diabetes, raised serum CXCL10 and normal CCL2 concentrations signal a predominant T-helper 1-driven autoimmune process, which shifts toward T-helper 2 immunity over the first 1-2 years from diagnosis.