Leptin binding activity (LBA) in plasma of nondiabetic and diabetic adolescents and obese children: relation to auxologic and hormonal data

Leptin circulates in serum bound to high molecular weight proteins. Hypothesizing that leptin binding proteins may regulate the functional efficiency of leptin, we characterized auxologic and hormonal factors that influence leptin binding in three disparate groups: normal adolescents, obese children, and teenagers with type I diabetes mellitus (IDDM). Specific leptin binding activity (sLBA) was assessed by column chromatography after incubation of serum with 125I-leptin in the presence and absence of excess unlabeled leptin. Mean sLBA was 17.0 +/- 7% (SD) in the healthy adolescents (n=41), 6.6 +/-4.3% in the obese children (n=26), and 14.9 +/-7.3% in the diabetic teenagers (n=17). At any value of sLBA, obese children had higher serum leptin levels than non-obese adolescents or diabetic teenagers, consistent with "leptin resistance" in the obese group. sLBA was higher in males than in females only in those with diabetes (18.6 +/- 7.3 vs 10.9 +/- 5.1%, p<0.05). sLBA correlated inversely with serum insulin-like growth factor-I values in the normal group (r= -0.45, p<0.01) and with insulin in the obese children (r= -0.53, p<0.01). There was no correlation between sLBA or serum leptin values and HbA1c, in the diabetic group. The serum leptin concentration was the principal determinant explaining the total variability of sLBA in all three cohorts. However, body mass index (BMI = weight/ height2) accounted for more of the total variability of percent specific binding in the healthy adolescents than in the other groups. We conclude that sLBA reflects circulating leptin levels, body composition, and hormonal milieu. Thus, in addition to leptin, qualitative and quantitative characteristics of leptin binding may play a physiological role in the regulation of appetite and in the "leptin resistance" of obesity.     

肾病综合征患儿血清铁与转铁蛋白的变化

目的：肾病综合征(NS)患儿尿中丢失白蛋白的同时也伴有转铁蛋白的丢失,测定血清铁及转铁蛋白等铁代谢相关指标以及尿转铁蛋白,了解其变化及其相互关系。方法：NS患儿37例,测定其治疗前和恢复期铁代谢相关指标(血清铁、铁蛋白、转铁蛋白、转铁蛋白饱和度、总铁结合力以及外周血红细胞参数)及尿转铁蛋白,并与正常对照组比较。结果：①在NS治疗前血清铁为18.8±3.8μmol/L,分别与恢复期的21.0±3.5μmol/L,及对照组的22.2±3.8μmol/L比较,差异有显著性(P<0.01);转铁蛋白为1.9±0.3g/L,分别与恢复期的2.9±0.6g/L和对照组的3.1±0.5g/L比较,差异有显著性(P<0.01);总铁结合力为56.4±9.2μmol/L,分别与恢复期的51.9±7.7μmol/L和对照组的50.7±6.8μmol/L比较,差异亦有显著性(均P<0.01);转铁蛋白饱和度为(55.7±9.2)%,与NS恢复期及对照组的(47.4±13.3)%,(46.4±8.2)%比较,差异有显著性(P<0.01)。②血清白蛋白与转铁蛋白呈正相关(r=0.609,P<0.01)。③血清转铁蛋白浓度与尿转铁蛋白呈负相关(r=-0.550,P<0.01)。结论：NS患儿血清铁及转铁蛋白明显降低,可能与转铁蛋白从尿中丢失有关。     

Inflammation, insulin, and endothelial function in overweight children and adolescents: the role of exercise

OBJECTIVES: To assess subclinical inflammation, fasting insulin, and endothelial function before and after exercise in overweight children and adolescents. STUDY DESIGN: Twenty-five children (body mass index [BMI] >85th percentile) were assessed for brachial artery flow-mediated dilation (FMD), nitroglycerin-induced dilation, C-reactive protein (CRP), lipids, glucose, insulin, oral glucose tolerance, body composition, aerobic fitness (peak oxygen uptake [VO 2 peak]), and blood pressure. Twenty of these persons were equally and randomly assigned to either 8 weeks of stationary cycling or to a non-exercising control group. RESULTS: A baseline correlation was found between CRP and fasting insulin (r = 0.62; P < .001), which remained significant after adjusting for baseline variables (r = 0.53; P < .05). After 8 weeks, significant improvements were observed in the exercise group compared with the control group for VO 2 peak (exercise group = 21.8 +/- 2.1 to 23.2 +/- 1.5 mL/kg/minute vs control group = 23.4 +/- 1.6 to 20.9 +/- 2.2 mL/kg/minute; P < .05), high-density lipoprotein (HDL) cholesterol (exercise group = 1.02 +/- 0.03 to 1.10 +/- 0.04 mmol/L vs control group = 1.08 +/- 0.07 to 0.99 +/- 0.09 mmol/L; P < .05), and FMD area under the curve (AUC) (exercise group = 746 +/- 66 to 919 +/- 94 %*sec vs control group = 731 +/- 102 to 515 +/- 73 %*sec; P < .05). CONCLUSIONS: In overweight children and adolescents, CRP is independently associated with fasting insulin. Eight weeks of aerobic exercise improves fitness, HDL cholesterol, and endothelial function in this group.     

Serum leptin levels in premature pubarche and prepubertal girls with and without obesity

Leptin can be regarded as a marker of the nutritional status of the body. This study was performed to determine the correlation of leptin levels with insulin (I) and androgens in girls with premature pubarche (PP) and prepubertal controls (C) with (OB) or without (nOB) obesity. We studied 25 girls with PP and 14 C; girls were dived into two subgroups according to body mass index (BMI): OB (18 PP and 8 C) and nOB (7 PP and 6 C). Obesity was defined as BMI >95th percentile for chronological age. Serum levels of leptin, I, glucose (G), DHEAS, testosterone, androstenedione (A), cortisol, SHBG, IGFBP-1 and lipid profile were measured. The fasting G to I ratio (FGIR) was calculated and FGIR <7 was considered as suggestive of I resistance (IR). Data were analyzed comparing PP vs C and OB vs nOB. Serum DHEAS (0.60 +/- 0.45 vs 0.18 +/- 0.22 microg/ml) and A (895.5 +/- 420.4 vs 457.0 +/- 352.1 pg/ml) levels were significantly higher in PP than C. Other hormonal and metabolic parameters were similar. Serum leptin (30.8 +/- 18.3 vs 8.1 +/- 5.9 ng/ml), A (841.8 +/- 471.1 vs 522.5 +/- 317.2 pg/ml), DHEAS (0.53 +/- 0.44 vs 0.31 +/- 0.39 microg/ml), G (88.4 +/- 8.8 vs 80.2 +/- 8.1 mg/dl), I (13.5 +/- 7.7 vs 5.1 +/- 3.7 microU/ml) and total cholesterol (TC) (180.5 +/- 30.9 vs 161.8 +/- 29.5 mg/dl) levels were greater in the OB than in the nOB group. IR was observed in 10 girls with OB and in one with nOB. Leptin was correlated with BMI (r = 0.83), SHBG (r = -0.44), IGFBP-1 (r = -0.47), I (r = 0.37), A (r = 0.48) and TC (r = 0.36), but in multiple regression analysis only with BMI (r2 = 0.72, p < 0.001). Girls with PP and prepubertal OB girls showed elevated leptin levels independent of I and androgen levels. Girls with OB had a greater degree of hyperandrogenism and IR. As obesity, IR and hyperandrogenism are common findings in polycystic ovary syndrome (PCOS), which is more prevalent in young women with a history of PP, a role of leptin in PCOS can be suggested. In addition, girls with PP could be considered a population at risk for plurimetabolic syndrome.     

Correlates of adiponectin and the leptin/adiponectin ratio in obese and non-obese children

Adiponectin is an adipocyte secreted protein that has been reported to increase fatty acid oxidation and improve insulin sensitivity. Our aim was to study the relationship between adiponectin and leptin, body fat, insulin and lipoproteins in obese compared to non-obese children matched for age and gender. Adiponectin serum concentrations were significantly lower in the obese compared to the non-obese children (9.1+/-3.7 vs 17.1+/-12.3 microg/ml, p <0.05), in contrast to serum leptin concentrations which were greater in the obese compared to the non-obese subjects (31.8+/-11.1 vs 8.2+/-5.7 ng/ml, p <0.001). When considered as a single group to assess adiponectin concentrations over a spectrum of body size, adiponectin values correlated inversely with body weight (r = -0.33, p <0.05) and BMI (r = -0.35, p <0.05). Adiponectin values correlated directly with HDL-C (r = 0.47, p <0.005), but not with total cholesterol, IGF-I, or leptin binding activity. Since leptin and adiponectin change inversely in relation to BMI, the leptin/adiponectin (L/A) ratio was determined as a potential index relating adiposity to the development of complications of obesity. The L/A ratio was eight-fold greater in the obese compared to the non-obese children, and correlated more strongly with BMI (r = 0.779, p <0.0001) and with HDL-C (r = -0.53, p <0.001), than did adiponectin alone. The L/A ratio also correlated significantly with triceps skinfold thickness (TSF) (r = 0.77, p <0.001) and percent body fat (r = 0.79, p <0.0001) in non-obese children. These data suggest that adiponectin concentrations are already differentially regulated in childhood obesity. The index of increased leptin concentration corrected by reduced adiponectin values (L/A ratio) merits investigation as a marker for morbidities associated with childhood obesity.     

盐酸二甲双胍改善代谢综合征青少年脂联素水平和胰岛素敏感性的研究

目的观察盐酸二甲双胍治疗青少年代谢综合征(MS)前后血清脂联素水平和胰岛素敏感性的变化。方法对348例(男208例,女140例)7~16岁[(11.47±2.12)岁]中、重度肥胖青少年进行体检和生化检测、口服葡萄糖耐量试验,检出其中符合MS诊断标准的36例,设为MS组,无生化检测异常的单纯性肥胖61例,设为单纯肥胖组。另设24例非肥胖青少年为对照组。对三组进行总体胰岛素敏感指数、稳态模型胰岛素抵抗指数(HOMA-IR)和血清脂联素等的比较。对MS组患儿中20例给予连续口服盐酸二甲双胍治疗3个月,观察治疗前后的HOMA-IR和血清脂联素、生化指标的变化。结果(1)HOMA-IR水平由低到高依次为对照组、单纯性肥胖组、MS组;胰岛素敏感指数和血清脂联素水平排序正好相反;HOMA-IR、胰岛素敏感指数和血清脂联素在3组间比较,差异均有统计学意义(均P<0.01)。(2)连续应用盐酸二甲双胍治疗满3个月的20例MS患儿:HOMA-IR下降[治疗前5.7(1.9~12.4),治疗后2.9(0.9~7.4),t=5.05,P<0.01],血清脂联素上升[治疗前(3.0±0.9)mg/L,治疗后(6.1±1.9)mg/L,t=6.19,P<0.01],血压、2 h血糖、甘油三酯、胆固醇、肝酶均有不同程度下降,治疗前后比较,差异有统计学意义(均P<0.01)。结论MS青少年脂联素水平和胰岛素敏感性比单纯性肥胖更低;应用盐酸二甲双胍治疗后MS青少年的脂联素水平上升,胰岛素敏感性改善,临床多项指标好转。     

Insulin resistance and ferritin as major determinants of abnormal serum aminotransferase in severely obese children.

OBJECTIVES: Liver involvement is a common complication of obesity related in part to insulin resistance. The role of ferritin has not been investigated in children. The aim was to determine the prevalence of liver enzyme abnormalities in severely obese children and to look for relationships between fat mass distribution, insulin resistance, and plasma ferritin. METHODS: 197 children with severe obesity (defined as a body mass index Z-score (BMI-Z) > 3.0) were studied prospectively from 2001 to 2004. Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) values were measured, as well as anthropometric characteristics: blood pressure; body composition by dual energy X-ray absorptiometry, and plasma fasting glucose, insulin, leptin, lipid, and ferritin concentrations. RESULTS: Serum ALT and AST values were abnormal in 23 (11.7%) and 13 (6.6%) children, respectively. By univariate analysis, serum ALT and AST values were positively correlated with android fat mass distribution (P < 0.0001 and P = 0.005, respectively) after adjustment for age, sex, ethnicity, and Tanner stage. Using the same model, a positive correlation and a positive trend linked plasma ferritin to serum AST (P = 0.02) and serum ALT (P = 0.06), respectively. Serum ALTwas positively correlated to insulin resistance (P = 0.03). Using a multivariate model, with the android/gynoid fat mass ratio as an additional independent variable, ferritin remained correlated with serum AST and ALT (P = 0.001 and P = 0.008, respectively). CONCLUSIONS: Abnormal serum aminotransferase values are uncommon in severely obese children in France. Android fat mass distribution, insulin resistance, and higher ferritin concentrations are significantly associated with liver abnormalities in our cohort.     

非酒精性脂肪性肝病儿童血清TIMP-1和TIMP-2检测及临床意义

目的：了解非酒精性脂肪性肝病患儿基质金属蛋白酶组织抑制物（TIMP）-1和TIMP-2的水平及价值。方法根据诊断标准将105例肥胖儿童分为单纯性肥胖（n=44）、单纯性非酒精性脂肪肝（SNAFL,n=25）和非酒精性脂肪肝炎（NASH,n=36）3组,采用酶联免疫吸附方法(ELISA)测定血清TIMP-1、TIMP-2,全自动酶法测定丙氨酸氨基转移酶(ALT)和γ-谷氨酸转肽酶(γ-GT)。结果随着单纯性肥胖向SNAFL和NASH发展,TIMP-1和γ-GT水平逐步升高,差异有统计学意义(P0.05)。结论 血清TIMP-1和TIMP-2指标均可不同程度地反映肝脏的纤维化程度,其中以TIMP-1更为可靠、有效。［中国当代儿科杂志,2010,12（6）：455-458］     

Enteral erythropoietin increases plasma erythropoietin level in preterm infants: a randomized controlled trial

OBJECTIVE: To evaluate the effects of enteral administration of recombinant human erythropoietin (rhEPO) on serum level of erythropoietin and erythropoiesis in preterm infants. STUDY DESIGN: Randomized controlled trial. SETTING: Level III NICU. SUBJECTS: 16 preterm infants less than 34 wk with birth weight less than 1800 g. INTERVENTION: Enteral rhEPO 400 U/kg, three times/week, plus FeSO4,3-6 mg/Kg/day ( Study group, n = 7) or FeSO4 only (Control group, n = 9). OUTCOME MEASURES: Hemoglobin, serum erythropoietin (EPO), reticulocyte count, and serum ferritin levels, measured at baseline, after 10 days and at discharge. RESULTS: Mean birth weight and gestational age for the Study and the Control groups were 1328.5 +/- 267.4 vs. 1392.8 +/- 196.7 g and 30.7 +/- 2.5 vs. 30.2 +/- 0.9 weeks, respectively. At discharge, there was no difference in hemoglobin or hematocrit but the reticulocyte counts were significantly higher in the Study group (1.4 +/- 0.7 vs. 0.7 +/- 0.4, P = 0.03). Serum erythropoietin level was significantly higher in the Study group (18 +/- 11 vs. 8.6 +/- 3.9 mU/mL, P = 0.006). Conversely, serum ferritin level was lower in the study group but did not achieve statistical significance. CONCLUSIONS: Enteral administration of rhEPO in preterm infants resulted in increase in serum erythropoietin and reticulocyte counts at the time of discharge without significantly affecting hemoglobin or hematocrit.     

Assessment of insulin sensitivity from measurements in fasting state and during an oral glucose tolerance test in obese children

BACKGROUND: Few previous studies have examined the validity of the fasting glucose-to-insulin ratio (FGIR), homeostasis model assessment of insulin resistance (HOMA-IR) and quantitative insulin-sensitivity check index (QUICKI) in pediatric populations. OBJECTIVE: To compare simple indices of insulin resistance calculated from fasting glucose and insulin levels with insulin sensitivity indices (area under the response curve [AUCinsulin], insulin sensitivity index [ISI-compositeL) determined by oral glucose tolerance testing (OGTT) in obese children. METHODS: One hundred and forty-eight obese children and adolescents (86 girls and 62 boys, mean age: 10.86 +/- 3.08 years, mean body mass index (BMI): 27.7 +/- 4.2) participated in the study. OGTT was performed in all participants. After glucose and insulin measurements from OGTT, the children were divided into two groups according to the presence or absence of insulin resistance. Insulin sensitivity indices obtained from the OGTT were compared between the groups. The total plasma glucose response and insulin secretion were evaluated from the AUC estimated by the trapezoid rule. Cut-off points, and sensitivity and specificity calculations were based on insulin resistance with receiver operating characteristic curve (ROC) analysis. RESULTS: The prevalence of insulin resistance, glucose intolerance and dyslipidemia was 37.1%, 24.3% and 54% in obese children, respectively. The groups consisted of 93 children without insulin resistance (54 girls and 39 boys; mean age: 10.5 +/- 3.3 years; mean BMI: 27.0 +/- 4.2) and 55 children with insulin resistance (32 girls and 23 boys; mean age: 11.4 +/- 2.5 years; mean BMI: 27.9 +/- 3.9). There were significant differences in mean FGIR (10.0 +/- 7.2 vs 5.6 +/- 2.8, p < 0.001), HOMA-IR (3.2 +/- 2.3 vs 4.9 +/- 2.3, p < 0.001) and QUICKI (0.33 +/- 0.03 vs 0.30 +/- 0.02, p < 0.001) between the groups. The cut-off points for diagnosis of insulin resistance were < 5.6 for FGIR (sensitivity 61.8, specificity 76.3), > 2.7 for HOMA-IR (sensitivity 80, specificity 59.1), and < 0.328 for QUICKI (sensitivity 80, specificity 60.2). CONCLUSIONS: Indices derived from fasting samples for diagnosis of insulin sensitivity are reliable criteria in obese children and adolescents. HOMA-IR and QUICKI appeared to have similar sensitivity and specificity and to have higher sensitivity than FGIR.     

肥胖儿童非酒精性脂肪肝病与心血管疾病的相关性

目的：探讨肥胖儿童非酒精性脂肪肝病（NAFLD）与心血管疾病(CVD)的关系。方法：231例肥胖儿童以及24例非肥胖儿童(对照组)进行临床、生化指标及颈动脉内膜-中层厚度（IMT）各项检查,根据诊断标准将231例肥胖儿童分为肥胖无肝脏损伤组（OCWLD）75例和NAFLD组156例。比较各组儿童临床、生化各项指标及IMT。结：果NAFLD组患儿IMT为0.066±0.021 cm,显著高于OCWLD组和对照组（分别为0.060±0.011 cm,0.037±0.007 cm,均P＜0.05）,OCWLD组亦显著高于对照组,P<0.05。NAFLD组患儿高血压、高脂血症患病率分别为39.7%和40.4%,明显高于OCWLD组（分别为22.7%,29.3%）和正常对照组（分别为4.2%,12.6%）（P<0.05）。经逐步线性回归分析显示IMT与BMI、NAFLD、ALT呈正相关（调整R2=0.316,P<0.01）。结论：肥胖儿童NAFLD的出现不仅是CVD发生的早期标志,而且是CVD发生的早期状态。NAFLD的早期诊断和治疗是预防心血管疾病发生发展的关键。［中国当代儿科杂志,2010,12（7）：547-550］     

Iron status at 9 months of infants with low iron stores at birth

OBJECTIVE: To determine the 9-month follow-up iron status of infants born with abnormally low serum ferritin concentrations.Study design: Ten infants of >34 weeks' gestation with cord serum ferritin concentrations <5th percentile at birth (<70 microg/L) and 12 control infants with cord serum ferritin concentrations >80 microg/L had follow-up serum ferritin concentrations measured at 9 +/- 1 month of age. The mean follow-up ferritins, incidences of iron deficiency and iron-deficiency anemia, and growth rates from 0 to 12 months were compared between the two groups. RESULTS: At follow-up, the low birth ferritin group had a lower mean ferritin than the control group (30 +/- 17 vs 57 +/- 33 microg/L; P =.03), but no infant in either group had iron deficiency (serum ferritin <10 microg/L) or iron-deficiency anemia. Both groups grew equally well, but more rapid growth rates were associated with lower follow-up ferritin concentrations only in the low birth ferritin group (r = -0.52; P =.05). Both groups were predominantly breast-fed without iron supplementation before 6 months. CONCLUSIONS: Infants born with serum ferritin concentrations <5th percentile continue to have significantly lower ferritin concentrations at 9 months of age compared with infants born with normal iron status, potentially conferring a greater risk of later onset iron deficiency in the second postnatal year.     

Fatty liver in obese children: prevalence and correlation with anthropometric measurements and hyperlipidemia

The aim of this study was to evaluate the correlation of ultrasonography-proven fatty liver with liver functions, serum lipid levels and anthropometric measurements in children with exogenous obesity. Three hundred and twenty-two patients (183 girls, 56.8%) with a mean age of 11.4+/-3.2 years (4-18 years) who presented with the complaint of obesity were enrolled. In 38 (11.8%) patients, increased liver echogenicity resembling fatty liver was found (Group 1). The body mass index percentages of group 1 patients were significantly higher than of those without fatty liver (Group 2) (157.7+/-18.0 vs 151.3+/-17.8, p=0.038). Alanine and aspartate aminotransferase levels of group 1 patients were significantly higher than of group 2 (p=0.002 vs p=0.028, respectively). Triglyceride levels were significantly higher in group 1 patients (120.8+/-88.8 vs 100.5+/-58.5 mg/dl, p=0.044). In conclusion, ultrasonography is an easy and noninvasive method for the diagnosis of fatty liver in children with obesity. Body mass index and serum lipids were higher in group 1 patients. The diagnosis and early treatment of obesity in childhood is important for the prevention and better treatment of related complications. Thus, ultrasonography should be a part of the early evaluation of obese children.     

降钙素原和C-反应蛋白对儿童全身和局部细菌感染的诊断价值

目的 探讨降钙素原（PCT）和C-反应蛋白（CRP）对诊断全身和局部细菌感染的价值。方法 检索2011年1月至2012年6月在深圳市儿童医院住院病史系统中感染性疾病患儿的资料,分为全身细菌感染组（血培养阳性的严重脓毒症和败血症）,局部细菌感染组（急性化脓性扁桃体炎、泌尿系感染及化脓性骨关节炎）,病毒感染组（传染性单核细胞增多症和手足口病）。比较各组PCT、CRP水平和阳性率的差异。绘制受试者工作曲线（ROC）,计算曲线下面积（AUC）,评估PCT和CRP对全身和局部细菌感染的诊断价值。结果 148例患儿进入分析,全身细菌感染组19例,局部细菌感染组55例,病毒感染组74例。①CRP水平(mg·L-1)、PCT水平(μg·L-1)和PCT阳性率局部细菌感染组低于全身细菌感染组（CRP：21.35 vs 76.0,P＝0.001;PCT:0.10 vs 28.09, 32.7% vs 100%,P均<0.001）;CRP水平和阳性率局部细菌感染组高于病毒感染组（21.35 vs 4.0, 73.1% vs 27.0%, P均<0.001), PCT水平和阳性率局部细菌感染组与病毒感染组差异无统计学意义。3组WBC计数差异无统计学意义;WBC阳性率全身细菌感染组高于病毒感染组（84.5% vs 54.0%,P=0.017）,局部细菌感染组与全身细菌感染组、病毒感染组差异无统计学意义。②PCT水平和阳性率局部细菌感染合并全身炎症反应综合征（SIRS）患儿显著高于不合并SIRS者（0.40 vs 0.08,P＝0.002;60.0% vs 17.1%, P＝0.001）,CRP水平和阳性率无显著差异。③PCT和CRP诊断全身细菌感染的ROC AUC分别为0.99和0.84;诊断局部细菌感染的ROC AUC分别为0.54和0.78。结论 PCT是识别全身细菌感染和监测局部细菌感染进展而合并SIRS的敏感指标。鉴别局部细菌感染时,CRP较PCT敏感。     

瘦素/脂联素值与肥胖儿童体质量指数及糖脂代谢的关系

目的 探讨瘦素/脂联素(L/A)值与单纯性肥胖儿童体质量指数(BMI)、糖脂代谢及肥胖症发病的关系.方法 单纯性肥胖60例和57例健康儿童,采用放射免疫分析(RIA)法测定其血清瘦素水平;ELISA法测定其血清脂联素、空腹胰岛素(FINS)水平;免疫比浊法测定其血脂各成分.分析并比较血清瘦素、脂联素及L/A值与肥胖儿童BMI、糖脂代谢的相关性.结果 1.肥胖儿童血清瘦素、FINS和三酰甘油(TG)水平与健康对照组相比明显增加;脂联素水平降低,差异均有显著性(Pa＜0.05,0.01).2.单纯性肥胖儿童瘦素与BMI、FINS、TG水平均呈显著正相关(r=0.408,0.301,0.301 Pa＜0.05,＜0.01);脂联素水平与BMI、FINS、TG均呈显著负相关(r=-0.360,-0.413,-0.258 Pa＜0.01,＜0.05).3.L/A值与BMI、FINS、TG呈显著正相关(r=0.780,0.764,0.601 Pa＜0.001).结论 血清瘦素和脂联素与肥胖儿童的发病有关,可作为儿童肥胖的监控指标;L/A值较单独瘦素、脂联素更能反映肥胖症儿童的代谢状况,可为肥胖症儿童糖脂代谢提供更为有效的监测指标.     

Iron deficiency in children with attention-deficit/hyperactivity disorder

BACKGROUND: Iron deficiency causes abnormal dopaminergic neurotransmission and may contribute to the physiopathology of attention-deficit/hyperactivity disorder (ADHD). OBJECTIVE: To evaluate iron deficiency in children with ADHD vs iron deficiency in an age- and sex-matched control group. DESIGN: Controlled group comparison study. SETTING: Child and Adolescent Psychopathology Department in European Pediatric Hospital, Paris, France. PATIENTS: Fifty-three children with ADHD aged 4 to 14 years (mean +/- SD, 9.2 +/- 2.2 years) and 27 controls (mean +/- SD, 9.5 +/- 2.8 years). MAIN OUTCOME MEASURES: Serum ferritin levels evaluating iron stores and Conners' Parent Rating Scale scores measuring severity of ADHD symptoms have been obtained. RESULTS: The mean serum ferritin levels were lower in the children with ADHD (mean +/- SD, 23 +/- 13 ng/mL) than in the controls (mean +/- SD, 44 +/- 22 ng/mL; P < .001). Serum ferritin levels were abnormal (<30 ng/mL) in 84% of children with ADHD and 18% of controls (P < .001). In addition, low serum ferritin levels were correlated with more severe general ADHD symptoms measured with Conners' Parent Rating Scale (Pearson correlation coefficient, r = -0.34; P < .02) and greater cognitive deficits (r = -0.38; P < .01). CONCLUSIONS: These results suggest that low iron stores contribute to ADHD and that ADHD children may benefit from iron supplementation.     

Leptin levels decline steadily during prolonged fasting in lean children

OBJECTIVE: To evaluate the effects of fasting on serum leptin levels in lean children. STUDY DESIGN: Seventeen children, age 7.7 +/- 4.3 years with mean body mass index (BMI) of 16.7 +/- 2.7 kg/m(2), underwent standard diagnostic fasts for suspected hypoglycemia. Blood was sampled at 6-hour intervals for glucose, insulin, C-peptide, leptin, free and total insulin-like growth factor-1, insulin-like growth factor-binding protein-1, growth hormone, cortisol, ketones, and free fatty acids. RESULTS: Subjects fasted 15 to 40 hours, and initial leptin levels were related to BMI and age. Leptin declined by 0.5 ng/mL per each fasting hour (P = .008), using a longitudinal mixed effects model. Leptin dropped significantly from an initial mean +/- SEM during the first 6 hours of 15.9 +/- 5.5 ng/mL to 3.5 +/- 0.9 ng/mL at the end of fasting. Mixed longitudinal effects models demonstrated that leptin was significantly related to insulin over time (P < .0001) as well as C-peptide (P < .0001). Significant relations were also seen with total insulin-like growth factor-1 over time, beta-hydroxybutyrate and insulin, and insulin-like growth factor-binding protein-1 and insulin. CONCLUSIONS: After 6 hours, leptin levels steadily decline during prolonged fasting in lean children. The decline probably is related to the suppression of insulin secretion. Although baseline leptin levels were related to BMI and age, in the final fasting sample, leptin levels showed minimal variation in this pediatric cohort encompassing a wide age range.     

Ghrelin and leptin modulate immunity and liver function in overweight children

Background:  The rising prevalence of obesity represents a growing worldwide public health problem. Interactions of adipocytokines and low-grade systemic inflammation presently are considered important in the development of obesity, as well as associated chronic disease including bronchial asthma, obesity-related liver disease and type 2 diabetes mellitus. The purpose of the present study was to investigate metabolic, hormonal, immunologic and inflammatory factors in overweight children and to further clarify possible immunomodulatory effects of obesity-related hormones and cytokines.
Methods:  Forty-nine prepubertal overweight children and 49 age-matched controls of normal weight without underlying disease were enrolled. Levels of plasma ghrelin and serum leptin, cytokines (interleukin [IL]-4, IL-10, IL-12, 1L-13), C-reactive protein, immunoglobulin, and insulin were measured, and liver function tests were done to better understand their status in the setting of obesity.
Results:  Overweight subjects had significantly higher measures of adiposity (body mass indexI, % body fat) and had significantly higher serum levels of IgG, IgA and IgE than non-obese children ( P  = 0.038, 0.0043, 0.0034, respectively); the opposite was true for IgM ( P  = 0.025). The incidence of presumed non-alcoholic fatty liver disease was 28.6% in overweight children. In overweight children, serum leptin levels were associated with liver function index (aspartate aminotransferase/alanine aminotransferase ratio) and serum insulin levels. Some elevated immunoglobulin levels significantly correlated with plasma ghrelin levels and liver function index.
Conclusions:  It is possible that appetite-regulating hormones modulate both humoral immunity and liver function. Further studies with a larger number of subjects are needed to clarify the precise mechanisms of this association.     

Evidence for association between insulin resistance and premature carotid atherosclerosis in childhood obesity

The present study was undertaken to determine the presence and predictors of the subclinical atherosclerosis in obese children. Fifty obese children [mean age: 11.7 +/- 2.5 y, mean body mass index (BMI): 28.2 +/- 4.0 kg/m] and 50 age- and sex-matched healthy nonobese controls (mean age: 11.4 +/- 3.73 y, mean BMI: 17.6 +/- 3.0 kg/m) were enrolled in the present study. Oral glucose tolerance test was performed to all obese subjects. Common carotid artery intima-media thickness (IMT) was measured by high-resolution B-mode ultrasonography. Carotid artery IMT was significantly increased (0.0476 +/- 0.007 versus 0.033 +/- 0.011 cm; p < 0.001) in the obese group. There were significant relations between carotid artery IMT and insulin sensitivity indexes derived from fasting samples (fasting glucose to insulin ratio (FGIR; p = 0.004, r = -0.404), quantitative insulin-sensitivity check index (QUICK-I; p = 0.002, r = -0.401) and homeostasis model assessment of insulin resistance (HOMA-IR; p = 0.034, r = 0.300) in the obese group. In a multivariate regression model, QUICK-I emerged as independent correlates for mean IMT in obese children with the total variance explained being 20.7% (beta = -0.58, p < 0.001). We concluded that insulin resistance is an independent risk factor for increased carotid artery IMT in obese children.     

Decreased serum adiponectin: an early event in pediatric nonalcoholic fatty liver disease

OBJECTIVE: To evaluate the relative concentrations of cytokines in pediatric nonalcoholic fatty liver disease (NAFLD). STUDY DESIGN: Thirty children were evaluated at a fasting morning visit to a pediatric research unit. RESULTS: Compared with normal-weight children (n = 12) and children who were overweight (n = 11), children who had presumed NAFLD (elevated Alanine aminotransferase [ALT] with negative work-up) (n = 7) had significantly lower mean serum adiponectin levels (P = .004). Adiponectin negatively correlated with body mass index (r = -0.60, P = .001), insulin (r = -0.74, P < .001), glucose (r = -0.52, P = .004), and ALT (r = -0.53, P = .003). There was no difference between normal-weight, obese, and presumed NAFLD subjects in mean serum tumor necrosis factor alpha and interleukin-6 and -8 concentrations nor in tumor necrosis factor alpha and interleukin-8 and -10 levels in an ex vivo lipopolysaccharide-stimulated system. CONCLUSIONS: Serum adiponectin is reduced in children with elevated ALT, similar to adults. However, children with presumed NAFLD do not have elevated pro-inflammatory cytokine levels. This suggests that depressed adiponectin plays a more proximal role than elevated levels of circulating pro-inflammatory cytokines in the development of NAFLD in children.