Aerobic exercise capacity in normal adolescents and those with type 1 diabetes mellitus

OBJECTIVE: To compare the aerobic exercise capacity between normal adolescents and those with type 1 diabetes mellitus (T1DM). METHODS: An experimental group with 72 individuals diagnosed with T1DM aged 9--20, time from diagnosis 4.9 +/- 3.6 yr, without clinical cardiopulmonary disease or anemia and a control group (C) with 46 healthy individuals aged 10--18, matched by age, weight, height, body mass index, and lean and fat mass (kg), underwent an incremental aerobic exercising test on a motorized treadmill, where gas exchange variables - peak pulmonary ventilation (VE), peak oxygen consumption (VO(2)), and carbon dioxide production (CO(2)) - as well as their heart rate (HR) and time to exhaustion were recorded. RESULTS: Body mass composition had no significant difference between experimental and control groups, and male and female subjects had similar exercising performances. The mean of hemoglobin A1c in the control group was 5.2+/- 0.9% and in the diabetic group 8.1+/- 2.2%; p=0.000. The patients with T1DM showed lower levels of aerobic capacity than the control group. Their respective values for each variable were as follows: (i) maximal VO(2) (T1DM: 41.57+/-7.68 vs. C: 51.12+/- 9.94 mL/kg/min; p< 0.001) and (ii) maximal VE (T1DM: 76.39+/-19.93 vs. C: 96.90 +/- 25.72 mL/kg/min; p< 0.001). Patients with T1DM also had an earlier time to exhaustion (T1DM: 8.75+/-1.60 vs. 10.82+/-1.44 min). CONCLUSIONS: Adolescent patients with T1DM showed a reduced aerobic exercising capacity when compared to healthy peers matched to anthropometric conditions. This potential condition should be taken into consideration by the time of evaluation of the aerobic performance of these patients with glycemic control level.     

1型糖尿病患儿血清干扰素γ诱导蛋白10水平的变化及其意义

目的观察趋化因子干扰素γ诱导蛋白10（IP-10）在儿童1型糖尿病（T1DM）发病中的变化。方法用ELISA法检测50例T1DM患儿和30例健康儿童的血清IP-10水平,根据自身抗体存在与否、自身抗体阳性种类数及不同病程对IP-10进行分组比较。结果T1DM患儿血清IP-10水平[（367±131）ng／L]显著高于对照组[（133±43）ng／L],差异有统计学意义（t=9．49,P〈0．01）。其中自身抗体阳性组IP-10[（385±147）ng／L]和自身抗体阴性组IP-10[（311±101）ng／L]均高于对照组（t=8．99,P〈0．01;t=8．67,P〈0．01）,但该两组间差异无统计学意义。1种、2种和3种自身抗体阳性患儿血清IP-10水平差异无统计学意义（F=1．46,P〉0．05）。初发组和病程〉12年组的T1DM患儿血清IP-10均高于对照组（t=10．34,P〈0．01;t=4．36,P〈0．01）,而病程〉12年组血清IP-10水平低于初发组（t=4．30,P〈0．01）。结论T1DM患儿血清IP-10水平高于对照组,血清IP-10水平不受自身抗体阳性存在与否、自身抗体阳性种类多少的影响,随病程延长,血清IP-10水平逐渐下降。     

Inflammatory cytokine, growth factor and counterregulatory responses to exercise in children with type 1 diabetes and healthy controls

In children with type 1 diabetes (T1DM), altered adaptive responses to exercise (secretion of growth factors, inflammatory cytokines, and glucoregulatory mediators) may have potential implications in growth and development, early onset of disease complications, and incidence of hypoglycemia. We therefore measured a broad spectrum of exercise responses in 12 children with T1DM (seven males and five females) and 12 controls (six males / six females) aged 11-15 yr, during a 30-min exercise challenge @ 80% VO(2)max. Euglycemia was strictly controlled during exercise, and in diabetic patients a basal rate of i.v. insulin was allowed to maintain baseline insulin concentrations. Throughout the experiment, interleukin-6 (IL-6) concentrations (pg/mL) were markedly higher in T1DM vs. controls (preexercise: 5.0+/-1.3 vs. 1.9+/-0.6, p<0.02; end-exercise 5.3+/-1.2 vs. 2.7+/-1.0, p<0.05; 30-min postexercise: 8.2+/-2.2 vs. 3.9+/-0.8, p<0.05). A similar pattern was also observed with norepinephrine. Growth hormone (GH) concentration was similar in both groups at baseline and end-exercise, but in T1DM the exercise-induced GH remained significantly elevated 30 min after exercise (9.2+/-2.2 vs. 3.1+/-0.9 ng/L, p<0.01). The exercise-induced increase in glucagon elicited by exercise in controls was similar to that previously observed in healthy adults (10+/-3 pg/mL); however, it was significantly blunted in T1DM children (2+/-2 pg/mL, p<0.05). In conclusion, T1DM children displayed significant alterations in multiple aspects of their adaptive response to intense exercise.     

Low levels of vitamin D in North Indian children with newly diagnosed type 1 diabetes

Borkar VV, Devidayal, Verma S, Bhalla AK. Low levels of vitamin D in North Indian children with newly diagnosed type 1 diabetes. Background: To find out whether vitamin D levels are lower in children with newly diagnosed type 1 diabetes (T1D) as compared to non‐diabetic subjects. Methods: Plasma levels of vitamin D (25‐OHD) were measured by high performance liquid chromatography (HPLC) in 50 children aged between 6 and 12 yr within a week of diagnosis of T1D, and in 50 healthy children. Results: The mean levels of vitamin D were significantly lower in patients as compared to their controls [20.02 ± 10.63 ng/mL (50.05 ± 26.57 mmol/L) vs. 26.16 ± 12.28 ng/mL (65.4 ± 30.7 mmol/L), p‐value 0.009]. Twenty‐nine (58%) children in the study group were vitamin D deficient (25‐OHD level < 20 ng/mL or < 50 mmol/L) as compared to only 16 (32%) in the control group. Overall, 43 (86%) diabetic and 38 (76%) healthy children were either vitamin D deficient or insufficient. Conclusion: These results suggest that vitamin D levels are low at the onset of T1D, and they strongly support the need for further clinical studies to prospectively evaluate the effect of vitamin D supplementation on T1D rates in this patient population.     

Postprandial hyperlipidemia after a fat loading test in minority adolescents with type 2 diabetes mellitus and obesity

The continuing increase in the incidence of type 2 diabetes mellitus (DM2) and obesity in children and adolescents is attributable to excessive caloric intake. Abnormal lipid metabolism in the postprandial state leads to long exposure of the vasculature to hyperlipidemia. Most children and adolescents with DM2 are obese, and many have fasting hypertriglyceridemia. Clustering of hyperlipidemia, DM2 and obesity increases the risk for cardiovascular disease. We therefore studied lipids, insulin, C-peptide, and glucose in response to an oral fat load simulating the fat content of a high-fat, fast-food meal in 12 type 2 diabetic obese, 15 non-diabetic obese, and 12 non-diabetic non-obese (control) adolescents (aged 10-19 yr; 87% African-Americans). All three groups were age-, sex-, and sexual maturation-matched. Mean body mass indices were similar in the diabetes and obese groups (32.7 +/- 1.1 vs 35.8 +/- 1.6 kg/m2). All patients with DM2 had fasting C-peptide > 0.2 nmol/l (0.7 ng/ml) and negative diabetes-associated autoantibodies. Serum total cholesterol, triglyceride, high- and low-density lipoprotein cholesterol, insulin, C-peptide, and plasma glucose levels were measured at 0, 2, 4, and 6 h after the fat load. The area under the curve (AUC) was calculated by trapezoidal estimation. Triglyceride AUC was significantly greater in the diabetes group than in the other two groups (15.7 +/- 2.9 vs 9.2 +/- 0.7 and 7.5 +/- 0.7 mmol x h/l [1389 +/- 258 vs 819 +/- 60 and 663 +/- 62 mg x h/dl]; p < 0.02 and <0.004, respectively), as were insulin, C-peptide, and glucose AUCs. Incremental triglyceride response (delta triglyceride = peak - fasting) in the diabetes group was significantly higher than that in the control group (2.1 +/- 0.7 vs 0.8 +/- 0.1 mmol/l 189.7 +/- 58.4 vs 71.2 +/- 11.1 mg/dl]; p < 0.04). Insulin resistance was estimated using the homeostasis model assessment (HOMA), which was greater in the diabetes group than in the obese and control groups (14.4 +/- 2.8 vs 5.2 +/- 0.8 and 3.2 +/- 0.4; p < 0.001 and < 0.0001, respectively). The diabetes group was divided into subgroups of high and normal fasting triglycerides on the basis of triglyceride levels above and below the 95th percentile. The delta triglyceride in the subgroup with high fasting triglycerides was substantially greater than in the subgroup with normal fasting triglycerides (3.4 +/- 1.1 vs 0.8 +/- 0.2 mmol/l [305.2 +/- 96.8 vs 74.2 +/- 18.0 mg/dl]; p < 0.001). Total cholesterol and triglyceride AUCs were much greater in the high vs normal fasting triglycerides subgroup (33.0 +/- 2.9 vs 24.2 +/- 1.9 and 23.6 +/- 3.5 vs 7.8 +/- 0.6 mmol x h/l [1274 +/- 113 vs 934 +/- 72 and 2085 +/- 309 vs 692 +/- 49 mg x h/dl]; p < 0.02 and <0.0001, respectively), as were insulin and C-peptide AUCs. HOMA was greater in the high vs normal fasting triglycerides subgroup (20.8 +/- 4.0 vs 8.0 +/- 1.6; p < 0.0001). In addition to elevated plasma glucose levels, there were no significant differences in either insulin or lipid parameters among the diabetes subgroup with normal fasting triglycerides, the obese group, and controls. Our data suggest that postprandial hyperlipidemia in response to a fat loading test is present in adolescents with DM2 who already have fasting hypertriglyceridemia. The degree of insulin resistance as an underlying abnormality--not DM per se--determines the degree of postprandial lipemia.     

初发1型糖尿病患儿外周血单个核细胞FOXP3和CTLA-4表达的研究

目的：研究初发1型糖尿病患儿外周血叉状头转录因子( FOXP3)和细胞毒性T细胞相关抗原-4(CTLA-4)表达水平,探讨它们在1型糖尿病发病中的作用。方法选取50例初发1型糖尿病患儿和30例健康儿童,采用real-time PCR法研究FOXP3和CTLA-4 mRNA表达;ELISA方法检测血清中可溶性FOXP3( sFOXP3)和CTLA-4( sCTLA-4)蛋白水平;分别应用免疫印记法、高效液相离子层析法和电化学发光法测量糖尿病抗体、HbA1C及C肽。结果1型糖尿病患儿FOXP3 mRNA及蛋白表达低于对照组[0.95±0.48 vs.2.11±0.79,(6.27±1.49) ng/ml vs.(9.02±2.37) ng/ml,均P<0.01],而CTLA-4 mRNA及蛋白表达高于对照组[2.43±0.83 vs.1.94±0.84,(77.88±22.34) ng/ml vs.(65.97±12.11) ng/ml,P<0.01];1型糖尿病患儿FOXP3和CTLA-4基因与蛋白表达均呈正相关(r＝0.758、0.396,均P<0.05);FOXP3与CTLA-4蛋白表达具有相关性(r＝－0.624,P<0.05)。结论初发1型糖尿病患儿外周血FOXP3和CTLA-4的基因及蛋白表达异常,FOXP3调控CTLA-4在调节性T 细胞的表达,提示免疫机制参与1型糖尿病的发生。     

Autoantibodies in children with type 2 diabetes mellitus

To evaluate the frequency of autoantibodies to glutamic acid decarboxylase (GAD), protein tyrosine phosphatase-like protein (IA-2), and insulin (IAA) in children with type 2 diabetes mellitus (DM), we studied 37 children and adolescents whose type 2 DM was defined by fasting and 90-min standard liquid meal-stimulated serum C-peptide levels of >0.2 and >0.5 nmol/l (0.7 and 1.5 ng/ml), respectively. Mean fasting-stimulated serum C-peptide levels were 1.1 +/- 0.10 nmol/l (3.38 +/- 0.29 ng/ml) and 1.9 +/- 0.17 nmol/l (5.79 +/- 0.50 ng/ml), respectively. Eleven out of 37 patients (29.7%) were positive for at least one autoantibody: 8.1% (n = 3) had positive GAD, 8.1% (n = 3) had positive IA-2, and 27% (n = 10) had positive IAA. Nine of the 10 IAA-positive patients were on insulin treatment at the time of testing. Three of the 10 IAA-positive patients were also positive for GAD or IA-2. Since insulin treatment can stimulate IAA, we considered this to be less informative in classifying autoimmunity in DM. Therefore, GAD and IA-2 were considered primary autoimmune markers. Four out of 37 patients (10.8%) were positive for GAD (n = 3) or IA-2 (n = 3) or both (n = 2). Thus, low (10.8%) frequency of autoimmunity in children and adolescents is consistent with their clinical classification of type 2 DM based on the presence of residual C-peptide.     

Cytoplasmic islet cell antibodies remain valuable in defining risk of progression to type 1 diabetes in subjects with other islet autoantibodies

The discovery of islet cell antibodies (ICAs) was the prelude to the understanding that type 1 diabetes mellitus (T1DM) is a chronic autoimmune disease. The issue regarding whether or not the measurement of ICAs should be completely replaced by biochemical markers detecting islet autoantibodies (AAs) for the prediction of T1DM has been the subject of endless international debates. In light of this controversy, we assessed the current role of ICAs as a predictive marker for T1DM progression. We examined a cohort of 1484 first-degree relatives (FDRs) of T1DM probands from the Children's Hospital of Pittsburgh Registry. These relatives were consecutively enrolled between 1979 through 1984 and followed up to 22 yr. Serum obtained at the time of enrollment was assayed for ICAs, glutamic acid decarboxylase (GAD)65, insulin A (IA)-2 AA, and insulin AAs (IAAs). In FDRs who had ICAs in addition to GAD65 and IA-2 AAs, the cumulative risk of developing insulin-requiring diabetes was 80% at 6.7 yr of follow-up, whereas this risk in those with GAD65 and IA-2 AAs without ICAs was only 14% at 10 yr of follow-up (log rank: P < 0.00001). Cox regression analysis showed that diabetes risk was significantly associated with the presence of ICAs in both subjects with low titer and high titer GAD65 and IA-2 AAs. The addition of IAAs in GAD65 and IA-2 AA-positive relatives did not increase the cumulative risk for conversion to insulin-treated diabetes. We provide evidence that a subgroup of ICAs predicts a more rapid progression to insulin-requiring diabetes in GAD65 and IA-2 AA-positive relatives and should remain part of the assessment of T1DM risk for intervention trials. In addition, these findings provide impetus for efforts to identify a novel islet autoantigen(s) reactive with this ICA subset.     

Beta-cell response to intravenous glucagon in African-American and Hispanic children with type 2 diabetes mellitus

The incidence of type 2 diabetes mellitus (DM) in children and adolescents has substantially increased over the past decade. The present study was conducted to evaluate the beta-cell response to intravenous glucagon (a non-glucose secretagogue) in children with type 2 DM. Twenty pediatric patients with type 2 DM were compared to 15 control subjects matched for body mass index and sexual maturation. The patients' ages ranged between 10 and 19 years. The duration of DM ranged from 1 to 5 years. Nine patients were on insulin treatment and 11 were on diet alone (3 patients) or metformin (8 patients). The criteria for type 2 DM were absent islet cell (IA-2) and glutamic acid decarboxylase (GAD65) antibodies and a fasting serum C-peptide level of > or = 0.23 nmol/l. Plasma glucose and serum C-peptide levels were determined in the fasting state and six minutes after an intravenous injection of 1 mg of glucagon. The fasting and stimulated plasma glucose levels and the fasting serum C-peptide levels (1.02 +/- 0.43 vs 0.79 +/- 0.26 nmol/l, p < 0.05) were higher in the patients with DM compared to weight-matched control subjects. While the absolute C-peptide responses to glucagon were not different between the two groups, the stimulated C-peptide to glucose ratios were significantly lower in the patients with DM compared to controls (0.039 +/- 0.026 vs 0.062 +/- 0.033, p < 0.05). Patients with DM treated with diet or oral therapy had significantly greater basal and stimulated C-peptide concentrations, incremental C-peptide, and C-peptide to glucose ratios than patients on insulin treatment. Both the fasting and the stimulated C-peptide levels were inversely correlated with the duration of DM (r = -0.53, p < 0.05). HbA1c at one year follow-up was inversely correlated with glucagon-stimulated C-peptide levels at the time of the study (r = -0.658, p < 0.01) and positively correlated with the duration of diabetes (r = 0.671, p = 0.002). The apparently normal serum C-peptide levels measured after glucagon challenge in these children with type 2 DM reflect their higher glucose levels. The lower stimulated C-peptide to glucose ratios in these children with type 2 DM compared to normal controls demonstrate their diminished beta-cell response to intravenous glucagon, a non-glucose secretagogue. Among the patients with DM, a higher glucagon-stimulated serum C-peptide response was associated with diet/metformin treatment, a shorter duration of DM and predicted improved glycemic control up to one year later. Thus, the fasting and glucagon-stimulated serum C-peptide levels provide an estimate of the potential insulin secretory capacity of the beta-cell and may predict glycemic control in pediatric type 2 DM.     

Characterization of 33 488 children and adolescents with type 1 diabetes based on the gender‐specific increase of cardiovascular risk factors

Schwab KO, Doerfer J, Marg W, Schober E, Holl RW. Characterization of 33 488 children and adolescents with type 1 diabetes based on the gender‐specific increase of cardiovascular risk factors. Objectives: Characterization of children with type 1 diabetes (T1DM) regarding number and gender distribution of cardiovascular risk factors (cvRF) and of total cholesterol/high‐density lipoprotein cholesterol ratio (TC/HDL‐C ratio) for risk assessment. Methods: 33488 patients ≤18 years were included in this cross‐sectional analysis and placed into 5 categories by their number of cvRF. Dyslipidemia (TC >200 mg/dL, >5.17 mmol/L; and/or HDL‐C <35 mg/dL, <0.91 mmol/L; and/or LDL‐C >130 mg/dL, >3.36 mmol/L), elevated systolic and/or diastolic blood pressure (BP) ≥90th percentile, obesity >97th percentile, active smoking, and HbA1c ≥7.5% were considered as cvRF. Results: 65% had no or 1 cvRF. HbA1c ≥7.5% was the most frequently occurring cvRF followed by BP ≥90th percentile, dyslipidemia, smoking, and BMI >97th percentile. Age at diabetic onset ranged from 7.7 to 9.2 years and diabetes duration from 4.1 to 6.6 years. CvRF showed differences in disfavour of females except smoking and HDL‐C <35 mg/dL (0.91 mmol/L). Rate of females was 45% with 0 cvRF and 60% with 4 to 5 cvRF. TC/HDL‐C ratio showed no clear association to the number of cvRF. Conclusions: 35% of a pediatric T1DM population develops 2 or more cvRF thus increasing their cv risk in adulthood. With increasing numbers of cvRF, the percentage of girls is rising from 45% to 60% which might contribute to an assimilation of survival rates in female and male adults. TC/HDL ratio does not predict the extent of cardiovascular risk in pediatric T1DM.     

Type 2 diabetes in a 5‐year‐old and single center experience of type 2 diabetes in youth under 10

The worrisome rise in pediatric type 2 diabetes (T2DM) is most prevalent among minority ethnic/racial populations. Typically, T2DM occurs during puberty in high risk obese adolescents with evidence of insulin resistance. Screening for T2DM in obese youth can be a daunting task for pediatricians and differentiating between pediatric T1DM and T2DM in obese youth can be challenging for pediatric endocrinologists. There is very limited data regarding the prevalence of T2DM among youth < 10 years of age. Here we present the case of a 5‐year‐old Hispanic male diagnosed with T2DM after referral by his pediatrician for abnormal weight gain, acanthosis nigricans and an elevated HbgA1c. He subsequently became symptomatic for diabetes with confirmed hyperglycemia and HbgA1c of 9.7% (83 mmol/mol) at the time of formal diagnosis. Type 1 diabetes autoantibodies (GAD65, Islet, and ZincT8) and monogenic diabetes genetic tests were negative. Due to elevated liver enzymes and baseline HbgA1c, he received basal insulin as his initial therapy. In this paper, we will discuss this case and present an IRB approved retrospective review of the characteristics of the 20 T2DM patients <10 years of age identified to date in our pediatric diabetes center. This review highlights that while uncommon, the diagnosis of T2DM merits consideration even in prepubertal children. This is especially true when working with a high risk population, such as our Hispanic South Texas youth.     

Prediction and prevention of type 1 diabetes: update on success of prediction and struggles at prevention

Type 1 diabetes mellitus (T1DM) is the archetypal example of a T cell‐mediated autoimmune disease characterized by selective destruction of pancreatic β cells. The pathogenic equation for T1DM presents a complex interrelation of genetic and environmental factors, most of which have yet to be identified. On the basis of observed familial aggregation of T1DM, it is certain that there is a decided heritable genetic susceptibility for developing T1DM. The well‐known association of T1DM with certain human histocompatibility leukocyte antigen (HLA) alleles of the major histocompatibility complex (MHC) was a major step toward understanding the role of inheritance in T1DM. Type 1 diabetes is a polygenic disease with a small number of genes having large effects (e.g., HLA) and a large number of genes having small effects. Risk of T1DM progression is conferred by specific HLA DR/DQ alleles [e.g., DRB1*03‐DQB1*0201 (DR3/DQ2) or DRB1*04‐DQB1*0302 (DR4/DQ8)]. In addition, the HLA allele DQB1*0602 is associated with dominant protection from T1DM in multiple populations. A concordance rate lower than 100% between monozygotic twins indicates a potential involvement of environmental factors on disease development. The detection of at least two islet autoantibodies in the blood is virtually pre‐diagnostic for T1DM. The majority of children who carry these biomarkers, regardless of whether they have an a priori family history of the disease, will develop insulin‐requiring diabetes. Facilitating pre‐diagnosis is the timing of seroconversion which is most pronounced in the first 2 yr of life. Unfortunately the significant progress in improving prediction of T1DM has not yet been paralleled by safe and efficacious intervention strategies aimed at preventing the disease. Herein we summarize the chequered history of prediction and prevention of T1DM, describing successes and failures alike, and thereafter examine future trends in the exciting, partially explored field of T1DM prevention.     

Evaluation of the pancreas reserve in siblings of type I diabetic children

INTRODUCTION: The purpose of this study was to determine the pancreas reserve in siblings of diabetic patients by screening islet cell antibodies (ICA), insulin auto antibodies (IAA), reduced C-peptide levels, first-phase insulin release and the derangement of cellular immunity (reduction of natural killer cells, abnormality of the T cell subpopulations). METHODS AND RESULTS: Twelve siblings (aged 9.3 +/- 2.8 years) of diabetic children were evaluated and results were compared with the control group (12.1 +/- 3.5 years). For siblings of the diabetic children, fasting, post-prandial and glucagon response C-peptide mean values were 2.2 +/- 1.2, 7.2 +/- 7.1 and 5.3 +/- 3.6 ng/mL, respectively, while in the control group they were 1.5 +/- 0.8, 3.6 +/- 2.0 and 5.1 +/- 2.9 ng/mL, respectively. There were no differences between the two groups. In 33%, postprandial C-peptide, and in 11% of the siblings, glucagon response C-peptide values were exaggerated. In siblings the first phase insulin release (FPIR) during an intravenous glucose tolerance test was 128.5 +/- 96.6 (above the 50th percentile) and stimulated insulin release (SIR) was 103.8 +/- 92.5 (above 25th percentile). Sibling values were significantly lower than the control group (FPIR 152.4 +/- 42.5, P = 0.01; SIR 134.9 +/- 38.2, P = 0.01). Values for FPIR (in two children) and SIR (three cases) were below the 5th percentile. In one, FPIR and SIR levels were both below the 1st percentile. Islet cell antibodies and IAA were also present in this subject. Treatment with nicotinamide was started in the cases with FPIR and SIR below the 5th percentile. We did not observe overt diabetic symptoms during the follow-up period of more than 3 years. CONCLUSION: We recommend that borderline insulin secretion be tested annually in siblings who show insufficient FPIR.     

Postprandial chylomicron clearance rate in late teenagers with diabetes mellitus type 1

A delayed chylomicron (CM) clearance rate, a known risk factor for atherosclerosis, has been described in adults with diabetes type 1 (DM1). We determined the CM clearance rate in late teenagers with DM1, and the relationship between CM clearance rate and elevated plasma lipid concentrations in DM1 teenagers in poor metabolic control (as characterized by HbA(1c) percentage). Plasma lipids and CM clearance were determined in nine patients with DM1 (mean age +/- SD: 17.5 +/- 0.6 y) and four healthy controls (mean age +/- SD: 20.1 +/- 0.8 y), by measuring breath (13)CO(2), plasma triglyceride, retinyl palmitate, and (13)C-labeled oleic acid concentrations, after oral administration of a fat-rich meal together with vitamin A and (13)C-oleic acid. In patients with DM1, fasting triglyceride and cholesterol concentrations were positively correlated with HbA(1c) percentage (p < 0.05). Neither in DM1 patients, nor in controls, was an elevated triglyceride concentration (above 1.7 mmol/L) found. Yet, in 22% of DM1 patients, cholesterol concentration was above 5.2 mmol/L, but not in any of the controls. CM clearance rate in DM1 patients was similar to that in controls and did not significantly correlate with HbA(1c) percentage. Fasting lipid concentrations in DM1 patients were not significantly correlated with CM clearance rate. Present data indicate that elevated lipid concentrations in late teenagers with DM1 are not attributable to a delay in CM clearance rate. A delayed CM clearance rate at late teenager age is not a risk factor contributing to the increased risk for atherosclerosis in DM1.     

Electrogastrography in children and adolescents with type 1 diabetes: weak correlation with metabolic control parameters

AIM: To evaluate gastric myoelectrical activity with respect to duration and metabolic control of type 1 diabetes mellitus (T1DM). METHODS: 172 children and adolescents with T1DM (mean 14.4+/-3.7 y), divided into subgroups depending on diabetes duration (< 5 and > 5 y), and 35 healthy controls (mean 13.93+/-3.59 y) were examined. All subjects underwent electrogastrography (EGG) performed after overnight fasting. In subjects with T1DM, haemoglobin A1c (HbA1c) and blood glucose levels during EGG records were measured. RESULTS: 15.69% of T1DM patients and 91.42% of the controls fulfilled normal EGG criteria (p < 0.001). T1DM subjects had a lower percentage of fasting normogastria (34.56+/-27.35% vs 69.84+/-18.16%, p = 0.0001) and higher bradygastria (51.97+/-30.24% vs 19.11+/-15.01%, p = 0.0001) compared to controls. In diabetic patients, an increase in postprandial normogastria (60.37+/-23.96% vs 76.68+/-12.38, p < 0.05) and a decrease in bradygastria percentage (25.67+/-21.01% vs 9.58+/-7.13%, p < 0.05) was observed. In children with disease < 5 y, diabetes duration correlated with power ratio (r = - 0.27, p = 0.01), postprandial normogastria (r = - 0.24, p = 0.03) and tachygastria (r = 0.25, p = 0.02). Weak correlations between EGG parameters and glucose (preprandial dominant frequency r = - 0.19, p < 0.05; postprandial normogastria r = 0.23, p < 0.01) and HbA1c levels (preprandial bradygastria r = 0.19, postprandial dominant power r = 0.23; p < 0.05) were observed. CONCLUSION: Gastric myoelectrical rhythm derangement is present in a large proportion of young diabetic patients. Bradygastria is the most prominent EGG abnormality. Weak correlation was found between EGG parameters and diabetes metabolic control.     

Serum interleukin-18 levels are raised in diabetic ketoacidosis in Chinese children with type 1 diabetes mellitus

OBJECTIVE: To investigate the role of serum interleukin (IL-18) in children with type 1 diabetes mellitus (T1DM) and diabetic ketoacidosis (DKA). DESIGN: Case-control study. SUBJECTS: Sixty-one children with T1DM including 28 with DKA and 33 without DKA and 30 age - and sex-matched healthy controls were recruited. METHODS: Serum IL-18, IL-12, and IFN-gamma levels were measured in all subjects by enzyme linked immunosorbent assay. RESULTS: Serum IL-18 levels were significantly higher in patients with DKA than those in patients without DKA (759.2 +/- 353.8 pg/mL vs. 634.9 +/- 399.7 pg/mL, P = 0.001) and healthy controls (310.0 +/- 265.3 pg/mL). The serum IL-12 and IFN-gamma levels were not different between patients and controls (277.5 +/- 207 pg/mL vs. 351.4 +/- 223.4 pg/mL, P = 0.45 and 7.02 +/- 7.53 pg/mL vs. 5.59 +/- 5.34 pg/mL, P = 0.21, respectively). CONCLUSION: Serum IL-18 levels are increased in children with type 1 diabetes mellitus and could be a predictor of diabetic ketoacidosis.     

HLA-DRB1*08 allele may help to distinguish between type 1 diabetes mellitus and type 2 diabetes mellitus in Mexican children

BACKGROUND: It may be difficult to distinguish type 1 diabetes mellitus (T1DM) from type 2 diabetes mellitus (T2DM) in the pediatric population. Autoantibodies may help to differentiate both types of diabetes, but sometimes these are positive in patients with T2DM and negative in patients with T1DM. The human leukocyte antigen (HLA)-DR genotype has been associated with T1DM and with T2DM only in adults and in determined cases. AIM: To determine the differences in HLA class II allele frequencies in Mexican children with T1DM and T2DM. METHODS: We included 72 children with T1DM, 28 children with T2DM, and 99 healthy controls. All were Mexican, and diabetes was diagnosed according to the clinical and laboratory criteria established by the Expert Committee on the Diagnosis and Classification of Diabetes Mellitus. The HLA-DRB1 typing was performed using polymerase chain reaction-sequence-specific oligonucleotide probe and polymerase chain reaction sequence-specific primers. RESULTS: We found an increased frequency of HLA-DRB1*08 and a decreased frequency of HLA-DRB1*04 in the group with T2DM vs. T1DM [p = 0.0001, odds ratio (OR) = 10.58, 95% confidence interval (CI) = 3-40.8 and p = 0.0006, OR = 0.24, 95% CI = 0.11-0.53, respectively]. No significant differences were found between HLA-DRB1 alleles in T2DM vs. controls. In the group with T1DM, there was a significantly increased frequency of the HLA-DR4 and HLA-DR3 alleles relative to controls (p = 0.0000001, OR = 3.59, 95% CI = 2.2-5.8 and p = 0.00009, OR = 4.66, 95% CI = 2.1-10.3, respectively). CONCLUSION: There are significant differences in the HLA profile in Mexican children with T1DM and T2DM. HLA typing could play a role in the differentiation between both types of diabetes in this population.     

A two year observational study of nicotinamide and intensive insulin therapy in patients with recent onset type 1 diabetes mellitus

BACKGROUND AND AIMS: A number of trials have evaluated residual beta-cell function in patients with recent onset type 1 diabetes mellitus (DM1) treated with nicotinamide in addition to intensive insulin therapy (IIT). In most studies, only a slight decline of C-peptide secretion was observed 12 months after diagnosis; however, no data is available on C-peptide secretion and metabolic control in patients continuing nicotinamide and IIT for up to 2 years after diagnosis. PATIENTS AND METHODS: We retrospectively analysed data from 25 patients (mean age 14.7 years +/- 5 SD) with DM1 in whom nicotinamide at a dose of 25 mg/kg b. wt. was added from diagnosis (< 4 weeks) to IIT (three injections of regular insulin at meals + one NPH at bed time) and continued for up to 2 years after diagnosis. Data were also analysed from patients (n = 27) in whom IIT was introduced at diagnosis and who were similarly followed for 2 years. Baseline C-peptide as well as insulin dose and HbA1c levels were evaluated at 12 and 24 months after diagnosis. RESULTS: In the course of the follow-up, patients on nicotinamide + IIT or IIT alone did not significantly differ in terms of C-peptide secretion (values at 24 months in the two groups were 0.19 +/- 0.24 nM vs 0.19 +/- 0.13 nM, respectively). Insulin requirement (0.6 +/- 0.3 U/kg/day vs 0.7 +/- 0.2 U/kg/day at 24 months, respectively) did not differ between the two groups. However, HbA1c was significantly lower 2 years after diagnosis in patients treated with nicotinamide + IIT (6.09 +/- 0.9% vs 6.98 +/- 0.9%, respectively, p < 0.01). No adverse effects were observed in patients receiving nicotinamide for 2 years. CONCLUSION: Implementation of IIT with the addition of nicotinamide at diagnosis continued for 2 years improves metabolic control as assessed by HbA1c. In both nicotinamide and control patients, no decline in C-peptide was detected 2 years after diagnosis, indicating that IIT preserves C-peptide secretion. We conclude that nicotinamide + IIT at diagnosis of DM1 prolonged for up to 2 years can be recommended, but longer follow-up is required to determine whether nicotinamide should be continued beyond this period.     

Impaired beta-cell and alpha-cell function in African-American children with type 2 diabetes mellitus--"Flatbush diabetes"

The incidence of type 2 diabetes mellitus (T2DM) in children and adolescents has substantially increased over the past decade. This is attributed to obesity, insulin resistance and deficient beta-cell function. In children a pubertal increase in insulin resistance and an inability to mount an adequate beta-cell insulin response results in hyperglycemia. Adults with T2DM have a diminished first phase response to intravenous glucose and a delayed early insulin response to oral glucose. Long-term studies show progressive loss of beta-cell function in T2DM in adults; however, such long-term studies are not available in children. To characterize beta- and alpha-cell function in African-American adolescents with established T2DM, we used mixed meal, intravenous glucagon and oral glucose tolerance testing and compared them to obese non-diabetic controls. T2DM was defined as fasting C-peptide >0.232 nmol/l and absent autoimmune markers. BETA-CELL FUNCTION: Meal testing in 24 children and adolescents with T2DM, mean age 14 years, BMI 30 kg/m2, Tanner stage II-V, HbA1c 8.9%, were compared with BMI- and age-matched controls. Forty percent presented with DKA. Half were treated with insulin and half with diet/oral anti-diabetic agents. Although absolute C-peptide response in both groups was similar, the incremental rise in C-peptide relative to plasma glucose in the patients with T2DM compared to controls was 40% and 35% lower 30 and 60 min after the meal, p <0.007 and p <0.026. Glucagon testing in 20 pediatric patients with T2DM compared with 15 matched controls showed significantly lower 6 min stimulated C-peptide relative to the ambient plasma glucose in patients with T2DM compared to controls (0.039 +/- 0.026 vs 0.062 +/- 0.033, p <0.05). The clinical utility is that 78% of patients with a 6 min C-peptide <1.4 nmol required insulin, while 81% of those >1.4 nmol required oral anti-diabetic agents, p <0.0001. Furthermore, the duration of T2DM up to 5 years after diagnosis was associated with lower fasting and glucagon-stimulated C-peptide levels, implying worsening beta-cell function over time, even in children and adolescents. ALPHA-CELL FUNCTION: During meal testing, children and adolescents with T2DM had less suppression of plasma glucagon than non-diabetic controls; this was more severe with longer duration of T2DM and poorer glycemic control. BETA-CELL RECOVERY: In African-American and Hispanic adults, intensive treatment of blood glucose may achieve beta-cell recovery with 35-40% of newly diagnosed patients going into remission after 6 months treatment. They remain off anti-diabetic pharmacological agents in remission for a median of over 3 years with normal HbA1c levels. We hypothesize this to be due to removal of a critical component of glucose or lipotoxicity at the level of the beta-cell and/or peripheral tissue. Four of 20 African-American children presenting with mean glucose 650 mg/dl maintained normal HbA1c levels on small doses of metformin after initial treatment with multiple insulin injections with or without metformin. This suggests a marked recovery of beta-cell function, similar to that in adults. SUMMARY: T2DM in children, as in adults, is characterized by insulin deficiency relative to insulin resistance. Plasma C-peptide levels may be clinically useful in guiding therapeutic choices, since patients with lower levels required insulin treatment; beta-cell function is also diminished with longer duration of T2DM. The possibility exists that in children, as in adults, intensive glycemic regulation may allow for beta-cell recovery and preservation. Thus, optimum beta- and alpha-cell function are central to the prevention of DM and maintenance of good glycemic control in African-American and Hispanic children and adolescents with T2DM.     

Insulin detemir is characterized by a more reproducible pharmacokinetic profile than insulin glargine in children and adolescents with type 1 diabetes: results from a randomized, double-blind, controlled trial

Insulin detemir (detemir) has previously been shown to be associated with lower within-subject variability compared with other basal insulin preparations in adults with type 1 diabetes mellitus (T1DM). This randomized, double-blind, crossover trial compared the within-subject variability of detemir and insulin glargine (glargine) in pharmacokinetic properties in children and adolescents with T1DM. The trial enrolled 32 children and adolescents (19 girls and 13 boys; mean +/- SD: age 13 +/- 2.5 yr and T1DM duration 6.3 +/- 3.0 yr) with a hemoglobin A1c (HbA1c) of 7.9 +/- 1.0%. Participants were randomized to a specific treatment sequence in which a dose of 0.4 U/kg of detemir and glargine was injected subcutaneously 24 h apart at each of two dosing visits. Insulin concentrations were measured at frequent intervals for a period of 16-h post-dosing. Detemir showed statistically significantly less within-subject variability compared with glargine with a 3.1-fold and 2.9-fold lower coefficient of variation (CV, %) for the area under the concentration-time curve [AUC((0-16) (h))] and the maximum concentration (C(max)), respectively. Separate analyses demonstrated a 2.5-fold and 2.9-fold lower CV (%) with detemir in children (8-12 yr) and a 4-fold and 3.8-fold lower CV (%) with detemir in adolescents (13-17 yr). No safety concerns were raised during the trial. In conclusion, within-subject variability in pharmacokinetic properties was significantly lower for detemir than for glargine in children and adolescents with T1DM. This indicates a less variable absorption with detemir, which is expected to be associated with a more predictable therapeutic effect also in this population.