Relation of acanthosis nigricans to hyperinsulinemia and insulin sensitivity in overweight African American and white children

OBJECTIVES: Acanthosis nigricans (AN) has been proposed as a reliable marker of hyperinsulinemia, but its utility for predicting hyperinsulinism has not been systematically evaluated in overweight children. We examined the relationship of AN to hyperinsulinemia and body adiposity. STUDY DESIGN: One hundred thirty-nine children underwent physical examination for AN, body composition studies, an oral glucose tolerance test, and a hyperglycemic clamp. RESULTS: Thirty-five children (25%) had AN. AN was more prevalent in African Americans (50.1%) than in white subjects (8.2%, P < .001). Independent of race, children with AN had greater body weight and body fat mass (P < .001); greater basal and glucose-stimulated insulin levels during oral glucose tolerance test (P < .001); greater first-phase, second-phase, and steady-state insulin levels (P < .001); and lower insulin sensitivity (P < .001) during the hyperglycemic clamp. After adjusting for body fat mass and age, none of these differences remained significant. When categorized by fasting insulin, 35% with fasting insulin levels > 20 microU/mL and 50% with fasting insulin levels > 15 microU/mL did not have AN. Eighty-eight percent of children with fasting insulin levels > or = 15 microU/mL had a body mass index SD score > or = 3.0. CONCLUSIONS: AN is not a reliable marker for hyperinsulinemia in overweight children. Children with a race-, sex-, and age-specific body mass index SD scores > or = 3.0 should be screened for hyperinsulinemia, whether or not they have AN.     

肥胖儿童伴良性黑棘皮病与胰岛素抵抗19例分析

目的　探讨肥胖儿童伴良性黑棘皮病与胰岛素抵抗及 2型糖尿病的关系。方法2 0 0 3年 6月～ 2 0 0 3年 9月 ,在我院内分泌门诊及病房就诊的体重指数 (BMI)≥ 2 5的肥胖儿童共 76例 ,对其中伴黑棘皮病皮肤改变的 19例 ( 2 5 % )均行皮肤病理活检以明确诊断 ,同时对这些患儿行空腹血糖、空腹血胰岛素水平、空腹血糖 /胰岛素比值 (FGIR)及人体测量学参数 [腰围 /臀围比值(WHR) ,全身体脂含量 (FM)、体脂百分数 (BF % )、体重指数 (BMI) ]等的检测 ,并行葡萄糖耐量试验(OGTT试验 ) ,以探讨肥胖儿童伴良性黑棘皮病与胰岛素抵抗及 2型糖尿病的关系。结果　 19例良性黑棘皮病患儿人体测量学参数包括腰围 /臀围比值 ,全身体脂含量 (FM)、体脂百分数 (BF % )、体重指数 (BMI)及空腹血胰岛素水平明显高于正常对照组 (P <0 0 1) ,空腹血糖 /胰岛素比值 (FGIR) ( 4 2 7± 0 5 3)小于 7,存在明显的胰岛素抵抗 ,其中 1例诊断为 2型糖尿病 ,10例有糖耐量异常。结论　儿童良性黑棘皮病与肥胖、高胰岛素血症 ,胰岛素抵抗及 2型糖尿病密切相关 ,是临床胰岛素抵抗的皮肤标志     

Glucose tolerance status in 510 children and adolescents attending an obesity clinic in Central Italy

Brufani C, Ciampalini P, Grossi A, Fiori R, Fintini D, Tozzi A, Cappa M, Barbetti F. Glucose tolerance status in 510 children and adolescents attending an obesity clinic in Central Italy. Childhood obesity is epidemic in developed countries and is accompanied by an increase in the prevalence of type 2 diabetes (T2DM). Aims: Establish prevalence of glucose metabolism alterations in a large sample of overweight/obese children and adolescents from Central Italy. Methods: The study group included 510 overweight/obese subjects (3–18 yr). Oral glucose tolerance test (OGTT) was performed with glucose and insulin determination. Homeostatic model assessment of insulin resistance (HOMA‐IR) and insulin sensitivity index (ISI) were derived from fasting and OGTT measurements. Beta‐cell function was estimated by insulinogenic index. Fat mass was measured by dual‐energy x‐ray absorptiometry. Results: Glucose metabolism alterations were detected in 12.4% of patients. Impaired glucose tolerance (IGT) was the most frequent alteration (11.2%), with a higher prevalence in adolescents than in children (14.8 vs. 4.1%, p < 0.001); silent T2DM was identified in two adolescents (0.4%). HOMA‐IR and glucose‐stimulated insulin levels were higher in patients with IGT than individuals with normal glucose tolerance (HOMA‐IR = 4.4 ± 2.5 vs. 3.4 ± 2.3, p = 0.001). Fat mass percentage and insulinogenic index were not different between the two groups. In multivariate analysis, age, fasting glucose, and insulin resistance influenced independently plasma glucose at 120 min of OGTT. Individuals with combined impaired fasting glucose/IGT (IFG/IGT) and T2DM were older and had reduced plasma insulin values at OGTT when compared to patients with simple IGT. Conclusions: Glucose metabolism alterations are frequently found among children and adolescents with overweight/obesity from Central Italy. Age, fasting glucose, and insulin resistance are main predictors of IGT. We suggest the use of OGTT as a screening tool in obese European adolescents.     

Oral glucose tolerance test in children and adolescents: positives and pitfalls

Objectives:   To describe the glycaemic status (assessed by an oral glucose tolerance test (OGTT)) and associated comorbidities in a cohort of Australian children and adolescents at risk of insulin resistance and impaired glucose homeostasis (IGH).
Methods:   Twenty-one children and adolescents (three male, 18 female) (18 Caucasian, one Indigenous, two Asian) (20 obese, one lipodystrophy) referred to the Paediatric Endocrinology and Diabetes Clinic underwent a 2-h OGTT with plasma glucose and insulin measured at baseline, + 60 and + 120 min. If abnormal, the OGTT was repeated.
Results:   The mean (SD) age was 14.2 (1.6) years, BMI 38.8 (7.0) kg/m² and BMI-SDS 3.6 (0.6). Fourteen patients had fasting insulin levels >21 mU/L. Type 2 diabetes mellitus was diagnosed in one patient, impaired glucose tolerance (IGT) in four patients and impaired fasting glycaemia (IFG) in one patient. Despite no weight loss, only one patient had a persistently abnormal OGTT on repeat testing. Three patients with IGH were medicated with risperidone at the time of the initial OGTT. One patient who had persistent IGT had continued risperidone. The other two patients had initial OGTT results of IGT and diabetes mellitus type 2. They both ceased risperidone between tests and repeat OGTT showed normal glycaemic status.
Conclusions:   Use of fasting glucose alone may miss cases of IGH. Diagnosis of IGT should not be made on one test alone. Interpretation of glucose and insulin responses in young people is limited by lack of normative data. Larger studies are needed to generate Australian screening recommendations. Further assessment of the potential adverse effects of atypical antipsychotic medication on glucose homeostasis in this at-risk group is important.     

Repetitiveness of the oral glucose tolerance test in children and adolescents

BACKGROUNDData regarding the most suitable diagnostic method for the diagnosis of glucose impairment in asymptomatic children and adolescents are inconclusive. Furthermore, limited data are available on the reproducibility of the oral glucose tolerance test (OGTT) in children and adolescents who are obese (OB).AIMTo investigate the usefulness of the OGTT as a screening method for glucose dysregulation in children and adolescents.METHODSEighty-one children and adolescents, 41 females, either overweight (OW), OB or normal weight (NW) but with a strong positive family history of type 2 diabetes mellitus (T2DM), were enrolled in the present observational study from the Outpatient Clinic of Paediatric Endocrinology of the University Hospital of Patras in Greece. One or two 3-h OGTTs were performed and glucose, insulin and C-peptide concentrations were measured at several time points (t = 0 min, t = 15 min, t = 30 min, t = 60 min, t = 90 min, t = 120 min, t = 180 min).RESULTSGood repetitiveness was observed in the OGTT response with regard to T2DM, while low repetitiveness was noted in the OGTT response with regard to impaired glucose tolerance (IGT) and no repetitiveness with regard to impaired fasting glucose (IFG). In addition, no concordance was observed between IFG and IGT. During the 1^st and 2^nd OGTTs, no significant difference was found in the glucose concentrations between NW, OW and OB patients, whereas insulin and C-peptide concentrations were higher in OW and OB compared to NW patients at several time points during the OGTTs. Also, OW and OB patients showed a worsening insulin and C-peptide response during the 2^nd OGTT as compared to the 1^st OGTT.CONCLUSIONIn mild or moderate disorders of glucose metabolism, such as IFG and IGT, a diagnosis may not be reached using only one OGTT, and a second test or additional investigations may be needed. When glucose metabolism is profoundly impaired, as in T2DM, one OGTT is probably more reliable and adequate for establishing the diagnosis. Excessive weight and/or a positive family history of T2DM possibly affect the insulin and C-peptide response in the OGTT from a young age.     

不同指标在评价肥胖儿童胰岛素抵抗中的价值

目的探讨单纯性肥胖儿童胰岛素抵抗临床评估的指标。方法对单纯性肥胖和正常对照儿童进行葡萄糖耐量试验和胰岛素释放试验,在试验前及试验后30、60、120、180 min分别测血糖和胰岛素,并计算稳态模型胰岛素抵抗指数(HOMA-IR)、敏感指数(HOMA-IAI)、胰岛素分泌功能(HOMA-IS)、血糖曲线下面积与胰岛素曲线下面积比及空腹血糖和空腹胰岛紊的比值(FBG/FINS)等胰岛素抵抗评价指标。结果肥胖组FINS明显高于对照组,FBG、HOMA-IS与对照组无显著差异。HOMA-IR和HOMA-IAI之间具有显著相关性,r为-1,与FINS的r分别为0.913和-0.913,与FBG/FINS的r分别为-0.889和0.889,与曲线下面积比的r分别为-0.523和-0.523,P均<0.01。结论FINS、HOMA-IR、HOMA-IAI、血糖与胰岛素曲线下面积比、FBG/FINS均适用于肥胖儿童胰岛素抵抗的评估,尤以FINS、HOMA-IR、HOMA-IAI更可取。     

单纯性肥胖儿童黑色棘皮症与胰岛素抵抗性及细胞因子的关系

目的 探讨单纯性肥胖儿童的黑色棘皮症(AN)和体质量指数、胰岛素抵抗性、瘦素、血浆酶原纤维蛋白溶解原活化抑制剂(PAI-1)的关系。方法 单纯性肥胖儿童38例,其中AN阳性17例,测量身高、体质量、腹围、臀围,同时测血胰岛素、瘦素、空腹血糖、PAI-1。结果 AN阳性者肥胖度、腹围、空腹胰岛素、自动动态平衡标准评价胰岛素抵抗指数(HOMA-R)关系有显著差异,AN与体脂肪率间无关。AN阳性肥胖儿中均升高,PAI-1 40μg／L以上,瘦素30 μg／L以上者均为AN阳性。结论　单纯性肥胖儿童,特别是伴AN阳性肥胖儿,要特别注意随访观察2型糖尿病和冠状动脉疾病的发生和发展。     

糖耐量减低肥胖儿童胰岛素原和真胰岛素水平测定意义

目的　探讨血清胰岛素原 (PI)及真胰岛素 (TI)测定对肥胖并糖耐量异常患儿的临床意义。方法　选择肥胖并糖耐量减低 (IGT)患儿 2 1例 ,肥胖糖耐量正常 (NGT) 5 2例 ,正常对照组 4 0例。测定各组空腹血清PI、TI、血糖 (G)、胰岛素 (I)和C 肽 (C P) ,并计算PI/I、PI/C P、PI/TI及胰岛素抵抗指数。结果　 1.肥胖并IGT和并NGT两组患儿比较 ,G、PI、C P及胰岛素抵抗指数均明显增加 (P均 <0 .0 1)。 2 .IGT组糖尿病阳性家族史明显高于NGT组 (P =0 .0 2 4 )。结论　高PI、高C P和胰岛素抵抗是肥胖并IGT患儿的突出表现 ,可能是儿童2型糖尿病的预示指标。有糖尿病阳性家族史肥胖儿童更应警惕IGT发生     

Acanthosis nigricans as a clinical marker to detect insulin resistance in Caucasian children from West Virginia

The accuracy of acanthosis nigrcans (AN) as a dermatological clinical marker to predict insulin resistance (IR) has not been well established in children. A cohort of obese Caucasian children was prospectively recruited. Demographic data, body mass index values, and laboratory data were compared for the presence or absence of AN. A total of 76 children participated. In all, 46 (60.5%) children had AN, and 34 (44.7%) children were positive for IR (>3.16); 25 (32.9%) children were positive for both AN and IR. Sensitivity, specificity, positive and negative predictive values, and accuracy level for AN to detect IR in the obese children who participated in this study were 73.5%, 50%, 54.3%, 70%, and 49%, respectively. The correlation between insulin and fasting glucose levels in AN-negative or AN-positive patients was low (R (2) = 13% to 17%). Acanthosis nigricans was only a surrogate marker for IR. It is concluded that IR should be examined in every obese West Virginian child irrespective of his or her AN status.     

One‐hour plasma glucose concentration during the OGTT: what does it tell about β‐cell function relative to insulin sensitivity in overweight/obese children?

Tfayli H, Jung Lee S, Bacha F, Arslanian S. One‐hour plasma glucose concentration during the OGTT: what does it tell about β‐cell function relative to insulin sensitivity in overweight/obese children? Background: In adults 1‐h plasma glucose concentration cut‐point of 155 mg/dL (8.6 mmol/L) during the oral glucose tolerance test (OGTT) is a strong predictor of future diabetes risk. Objective: We tested the hypothesis that a 1‐h glucose concentration ≥155 mg/dL is associated with lower β‐cell function in overweight/obese youth. Research design and methods: One hundred and thirteen diabetes free overweight/obese youth aged 10–20 yr, underwent evaluation of β‐cell function during a 2 h hyperglycemic clamp ～225 mg/dL (12.5 mmol/L), and insulin sensitivity during a 3 h hyperinsulinemic–euglycemic clamp, and a standard 2 h OGTT. Body composition and abdominal adiposity were determined by DEXA and CT scan. The disposition index (DI) was calculated as the product of first‐phase insulin secretion and insulin sensitivity. Subjects were divided into two categories of 1‐h plasma glucose concentration: <155 mg/dL (n = 69) and ≥155 mg/dL (n = 44). Results: Youth with 1‐h glucose ≥155 mg/dL had lower DI than those with 1‐h glucose <155 mg/dL (295.1 ± 27.4 vs. 498.6 ± 37.7 mg/kg/min, p < 0.001), independent of the glucose tolerance status. In multiple regression models, DI was the strongest contributor to 1‐h glucose concentration explaining ～21% of its variance. Conclusions: Overweight/obese youth with 1‐h glucose ≥155 mg/dL during the oral glucose tolerance test have a significantly lower β‐cell function relative to insulin sensitivity even within the normal glucose tolerance range. Such youth may be at higher risk of future diabetes.     

Prevalence of glucose intolerance in school age children. Population based cross-sectional study

AIM: The aim of the study was to determine the prevalence of glucose intolerance among school children in south-eastern Poland. METHODS: Schools were randomly selected in the area and the entire school population was studied. We examined 1083 children (510 boys and 573 girls) in the mean age 14.49 years (age range: 7.9-19 years). Their weight and height were measured and body mass index (BMI) was calculated. Patients were classified as overweight or obese based on International Obesity Task Force (IOTF) criteria. We tested fasting glucose level in randomly selected children with normal weight (N=83) in all overweight and obese subjects (N=229). In children with fasting blood glucose level higher than 5.5 mmol/L (100 mg/dL) oral glucose tolerance test (OGTT) was performed. RESULTS: About 17.8% of children were overweight and 4.6% obese. Fasting hyperglycemia was found in 16.7% obese children. The calculated prevalence of fasting hyperglycemia for entire population was 6.7/1000. Impaired glucose tolerance (IGT) was found only in obese children. The prevalence of glucose intolerance in obese children was 7.1%, in contrast the calculated prevalence of glucose intolerance for the entire population was 3.0/1000 (95% confidence interval: 0-8.4/1000). CONCLUSION: Despite relatively high number of obese children, the prevalence of IGT among schoolchildren of south-eastern Poland remains low.     

Genetic factors and clinical significance of acanthosis nigricans in obese Japanese children and adolescents

AIM: To clarify the clinical significance of acanthosis nigricans (AN) and the association of gene polymorphisms in the ss2- and ss3-adrenergic receptors (B2ADR and B3ADR) in Japanese obese children and adolescents. METHODS: Seventy obese subjects (56 boys, 14 girls) from 5 to 19 y of age were examined as to clinical features. Genetic analyses were performed in 83 obese subjects (61 boys, 22 girls), 2 to 17 y of age. Typing of gene polymorphisms in B2ADR and B3ADR was achieved by polymerase chain reaction (PCR) of genomic DNA and restriction fragment-length polymorphism analysis (PCR-RFLP). RESULTS: The group with AN (n = 30) had higher values for percent overweight, BMI, waist circumference, fasting insulin, HOMA-R, leptin and PAI-1 than the AN-negative group (n = 40), but there were no significant differences in age, sex or percent body fat between the two groups. The prevalences of B2ADR Gly16 and B3ADR Arg64 were significantly higher in AN-positive (n = 26) than in AN-negative (n = 57) subjects. In addition, the AN frequency was significantly higher in the group with both Gly16 and Arg64 than in the group with neither of these alleles (55.6% vs 12.5%, p < 0.05). CONCLUSION: We demonstrate that AN is a useful clinical marker for the severity of obesity associated with a high BMI, and that B2ADR Gly16 and B3ADR Arg64 are associated synergistically with AN in obese children and adolescents.     

Differences in insulin resistance markers between children born small for gestational age or born preterm appropriate for gestational age

Aim: To evaluate the impact of prenatal or postnatal compromised environment on glucose homoeostasis in children born preterm and appropriate for gestational age or small for gestational age (SGA) at term. Method: Seventy-seven children (median 9.9 years, range 8.5–10) born at Karolinska Hospital were allocated to three groups: 21 subjects born before 30 weeks of gestational age (preterm), 26 SGA at term and 30 at term with appropriate birth weight (control). Anthropometric measurements were taken, and fasting blood samples for haemoglobin A1c, glucose, insulin, IGFBP-1, IGF-1 and lipid profile were taken. Glucose, insulin and IGFBP-1 samples were taken at 0, 30 and 120 min during an oral glucose tolerance test (OGTT). Results: Subjects born preterm or SGA were shorter and thinner compared with Controls. After adjustment for body mass index (BMI), the SGA group had higher basal insulin levels (p = 0.029), higher homoeostasis model assessment—insulin resistance (p = 0.012) and lower whole-body insulin sensitivity index (p = 0.007) than Controls. IGFBP-1 decrease during OGTT was attenuated in the Preterm group compared with the Control (p = 0.045) and SGA groups (p = 0.007). Conclusion: The higher fasting insulin level in the SGA children, adjusted for BMI, could indicate peripheral insulin resistance. Preterm born children had reduced suppression of IGFBP-1 during OGTT, suggesting hepatic insulin resistance.     

Significance of acanthosis nigricans in childhood obesity

Aim: Acanthosis nigricans (AN) is among the most common dermatologic manifestations of obesity and hyperinsulinism. In this study, we aimed to find the clinical and laboratory differences in obese children with AN and without AN (non‐AN). Methods: In total, 160 obese children were included in the study. The duration of obesity, body mass index (BMI), BMI z‐scores, birth weight, parental BMI, lipid profile, fasting and post‐meal (PM) glucose and insulin levels were compared in 67 obese with AN and 93 obese without AN. Results: Age was similar in both groups. AN group had higher male to female ratio (42/25 in AN, 43/50 in non‐AN; P = 0.03), higher BMI (30.3 ± 6.1 in AN, 26.4 ± 3.6 in non‐AN; P < 0.001) and weight for height (162.6 ± 28.8 in AN, 144.6 ± 15.8 in non‐AN; P < 0.001) than non‐AN group. There were no significant differences between the groups in birth weight, parental BMI and blood pressure. AN group had higher fasting (19.9 ± 16.2 mU/L in AN, 10.4 ± 7.6 mU/L in non‐AN; P < 0.001) and PM insulin (88.6 ± 87.3 mU/L in AN, 51.1 ± 42.0 mU/L in non‐AN; P = 0.01) and homeostasis model assessment for insulin resistance (HOMA‐IR) (4.0 ± 2.5 in AN, 2.2 ± 1.8 in non‐AN; P < 0.001) than non‐AN group. However, fasting and PM glucose, triglyceride, low‐density lipoprotein‐, high‐density lipoprotein‐ and total cholesterol levels were similar in both groups. BMI was correlated with HOMA‐IR in both groups (r = 0.40 for AN, r = 0.28 for non‐AN). PM glucose and PM insulin were correlated in both groups (r = 0.56 for AN, r = 0.39 for non‐AN). However, fasting glucose and fasting insulin were correlated in only non‐AN (r = 0.25), but not in AN group. Conclusions: Obese children with AN show higher insulin levels and HOMA‐IR. AN is an important predictor of the insulin resistance in childhood obesity. Insulin secretory dynamics seem to be disrupted in fasting state initially, which is reflected as the loss of fasting insulin–glucose correlation in AN group.     

Relation between Delayed Superfluous Insulin Secretion during An Oral Glucose Tolerance Test and Metabolic Disorders in Obese Japanese Children

The aim of this study was to clarify the relation between postprandial hyperinsulinemia and metabolic disorders in obese children. Twenty-eight obese Japanese children (8.8–16.2 yr) were divided into four groups: without impaired liver function and dyslipidemia (Group A), with impaired liver function (Group B), with dyslipidemia (Group C), and with impaired liver function and dyslipidemia (Group D). The levels of PG, serum immunoreactive insulin (IRI) and serum C-peptide (CPR) were measured during an oral glucose tolerance test (OGTT). The subjects had delayed superfluous insulin and CPR secretion during the OGTT compared with healthy references. In regard to the insulin secretion pattern, Group A’s response peaked at 60 min and then decreased gradually until 120 min, Group B’s response peaked at 60 min, remained at the peak until 120 min and then decreased gradually until 180 min, Group C’s response peaked at 120 min and then decreased gradually until 180 min, and Group D’s response peaked at 120 min and remained at the peak until 180 min. These results suggest that delayed superfluous insulin secretion during an OGTT is related to metabolic disorders in obese Japanese children and that these patients will experience a vicious cycle of postprandial hyperinsulinemia and metabolic disorders. It is important to prevent healthy children from becoming obese and to improve management of childhood obesity.     

Characterisation of morbidity in a UK, hospital based, obesity clinic

Aim

To identify clinical features which predict those most at risk of co‐morbidities within an obesity clinic.

Methods

Children attending an obesity clinic had fasting glucose, insulin, and lipids measured prior to a standard oral glucose tolerance test (OGTT). History and examination established birth weight, family history of type 2 diabetes/obesity, pubertal status, and presence of acanthosis nigricans. Central and total fat mass was estimated by bio‐impedance.

Results

Of the 126 children evaluated, 10.3% (n = 13) had impaired glucose tolerance (IGT); the majority (n = 11) of these would not have been identified on fasting glucose alone. Those with IGT were more likely to have a parental history of type 2 diabetes (relative risk 3.5). IGT was not associated with acanthosis nigricans. Twenty five per cent (n = 19) of those evaluated (n = 75) had evidence of the “metabolic syndrome” (MS). HDL cholesterol and triglyceride levels were related to insulin sensitivity (HOMA‐R); HDL cholesterol was also related to birth weight SDS. We observed a trend for those with MS to have a lower birth weight SDS. The severity of obesity did not influence the likelihood of IGT or MS.

Conclusions

Significant numbers of obese children have associated co‐morbidities. Analysis of fasting blood glucose samples alone is not satisfactory to adequately evaluate glucose homoeostasis. The overall level of obesity does not predict co‐morbidities. Special attention should be given to those with parental diabetes and a history of low birth weight who are more likely to have IGT and abnormal lipid profiles respectively.     

52例肥胖和超重儿童糖耐量及胰岛素释放试验分析

目的 了解肥胖和超重儿童糖代谢及胰岛细胞功能状况。方法 对52例单纯性肥胖与超重儿童进行口服糖耐量试验,并测定其血糖及胰岛素水平。计算胰岛素抵抗指数(IR),胰岛素敏感指数(IS),服糖后30min胰岛素增加值与血糖增加值的比值。并查甘油三酯、肝脏B超。体重指数(BMI)与IR之间、不同BMI组之间、糖耐量减低组与对照组之间进行比较。结果 发现糖尿病1例(1．9％),IGT者5例(9．6％)。IR≥2．8为胰岛素抵抗,占76．9％。BMI与IR之间无相关关系。不同BMI组之间IR、IS、服糖后30min胰岛素增加值与血糖增加值的比值差异均无统计学意义。糖耐量减低组与对照组之间IR、IS差异无统计学意义,服糖后30min胰岛素增加值与血糖增加值的比值之间差异有统计学意义。甘油三酯升高19例(37％),脂肪肝16例(53％)。结论 肥胖与超重儿童普遍存在胰岛素抵抗和敏感性下降,其与BMI程度无关。肥胖伴糖耐量减低儿童除胰岛素抵抗外存在明显的B细胞功能减退。许多肥胖和超重儿童同时存在脂代谢紊乱。     

Clinical and biochemical manifestations of syndrome X in obese children

The aim of this study was to investigate whether the clinical and metabolic characteristics of syndrome X had their onset in childhood in otherwise healthy but obese children of Greek origin. A group of 25 obese children and 18 age- and sex matched control subjects, aged 6–14 years, underwent an oral glucose tolerance test (OGTT), assessed for determination of plasma glucose and insulin levels. Insulin sensitivity and insulin resistance were estimated by mathematical models using calculations obtained during the OGTT. Body mass index (BMI) and blood pressure were measured, as well as serum lipoprotein and aminotransferase concentrations, after an overnight fast. The obese children had significantly higher blood pressure (systolic and diastolic) (P<0.001), triglycerides, lipoprotein(a) and alanine aminotransferase levels (P<0.05) and significantly lower HDL-cholesterol and apolipoprotein A-1 values (P<0.001). Plasma glucose levels during the OGTT were similar in both obese children and control subjects, while plasma insulin levels were significantly higher in obese children (P<0.01). In mathematical models, mean values of insulin sensitivity predictors: metabolic clearance rate and insulin sensitivity index were significantly lower in obese children (P<0.001). Predictors of beta-cell function: insulin resistance index and insulin release index were significantly higher in obese children (P<0.001). Conclusion:childhood adiposity was associated with all traditional components of syndrome X. The early recognition of these factors as predisposing elements of the appearance of metabolic syndrome requires the development of strategies to manage excess weight gain during childhood, with the ultimate goal being the prevention of type 2 diabetes and cardiovascular disease in adulthood.Abbreviations ApoA-1 apolipoprotein A-1 - ApoB apolipoprotein B - ALT alanine aminotransferase - AST aspartate aminotransferase - BMI body mass index - HDL-C HDL-cholesterol - HOMA-IR insulin resistance index - HOMA-Secr insulin release index - ISI insulin sensitivity index - LDL-C LDL-cholesterol - Lp(a) lipoprotein (a) - MCR metabolic clearance rate of glucose - OGTT oral glucose tolerance test - TC total cholesterol - TG triglycerides     

The abnormalities of carbohydrate metabolism in Turner syndrome: analysis of risk factors associated with impaired glucose tolerance

An oral glucose tolerance test (OGTT) was performed in 103 patients with Turner syndrome (TS) who had normal fasting and postprandial glucose levels. The plasma glucose, insulin, C-peptide and proinsulin levels were measured every 30 min during the test. Using a homeostatic model assessment (HOMA) and a quantitative insulin sensitivity check index (QUICKI), the insulin resistance in TS patients was investigated. Diabetes mellitus and impaired glucose tolerance (IGT) were newly diagnosed in two and 18 patients respectively. There was a significant increase in mean plasma glucose, insulin, C-peptide and proinsulin reponse during an OGTT in the IGT group in contrast to the normal glucose tolerance (NGT) group ( P <0.05). There was a significant decrease in the quantitative insulin sensitivity check index (QUICKI) in the IGT group in contrast to the NGT group ( P <0.05). The fasting insulin and triglyceride levels strongly predicted the 2 h glucose level during the OGTT ( P <0.05). Conclusion:The oral glucose tolerance test is superior to the fasting and postprandial plasma glucose test for the early detection of abnormalities of carbohydrate metabolism in patients with Turner syndrome.     

Impaired glucose tolerance and risk factors for progression to type 2 diabetes in youth

Abstract:  Impaired glucose tolerance and impaired fasting glucose represent two potentially reversible prediabetes conditions. Previous reports from various regions across the globe indicate that both conditions may be relatively common in obese children and adolescents. The major factor driving the development of compromised glucose metabolism in obese youth is severe insulin resistance. This severe insulin resistance has been strongly associated with specific patterns of lipid partitioning. Severe obesity along with continued weight gain, specifically in obese youth belonging to ethnic minorities, have been shown to be associated with deterioration of glucose tolerance over short periods of time. As obesity-related insulin resistance in the pediatric age-group is associated with the development of altered glucose metabolism and other elements of the metabolic syndrome, severely obese youth are a high-risk group for the development of type 2 diabetes and may benefit most from preventive interventions such as environmental changes that promote increased physical activity.