Prevalence of type 2 diabetes mellitus and impaired glucose tolerance in obese Argentinean children and adolescents

The aim of this study was to evaluate the prevalence of type 2 diabetes mellitus (DM2) and impaired glucose tolerance (IGT) in obese children and adolescents and to examine insulin resistance and insulin secretion. We studied 427 asymptomatic obese patients. DM2 and IGT were diagnosed by an oral glucose tolerance test. Insulin resistance and P-cell function were assessed by using homeostasis model assessment (HOMA), insulin/glucose index (I/GI), fasting insulin and insulin sensitivity index (ISI-composite). Thirty patients showed IGT (7%) and seven had DM2 (1.6%). The mean age was 10.7 +/- 3.5 years, the diabetic group being significantly older than the normal group (p < 0.01). The mean body mass index was 30 +/- 5.3 kg/m2 without significant differences between groups. beta-Cell function declined significantly in the patients with IGT and DM2, and insulin resistance increased significantly. Given the rather high prevalence of glucose metabolism impairment, children with obesity should undergo glucose tolerance testing for appropriate therapeutic intervention.     

Evaluation of glucose intolerance in adolescents relative to adults with type 2 diabetes mellitus

AIM: There is an increasing trend in the prevalence of type 2 diabetes mellitus (DM2) in childhood and adolescence, while positive family history of DM2 and obesity are the most important risk factors. To study the influence of family history and obesity on glucose intolerance in our country was the aim of this study. STUDY DESIGN AND METHODS: A total of 105 children and adolescents aged 10-18 years (mean 13.3 +/- 2.5 years) were included in the study. All children and adolescents were divided into three groups according to positive family history of DM2 and obesity, and an oral glucose tolerance test (OGTT) was performed for all. Prediabetes was defined as impaired glucose tolerance (IGT) and/or impaired fasting glucose (IFG). Insulin secretion and insulin resistance were estimated using the insulinogenic index; and the homeostatic model assessment for insulin resistance (HOMA-IR) and Matsuda index, respectively. RESULTS: The prevalence of prediabetes was 15.2% in the whole group, while it was 25.5% in obese children who also had a positive family history of DM2. The frequency of hyperinsulinism was 57.1% in all groups. Prediabetic children had significant insulin resistance (HOMA-IR 11.5 +/- 7.1 and 4.1 +/- 6.4, respectively, p = 0.034). CONCLUSIONS: Obesity and glucose intolerance are also a problem in developing countries. The risk of prediabetes in children is highest in obese children who also have a positive family history of DM2. There is a need for a lifelong preventive program starting in childhood to avoid DM2 and decrease cardiovascular risk factors     

Alterations of glucoregulation in childhood obesity--association with insulin resistance and hyperinsulinemia

AIM: To study the prevalence of alterations of glucoregulation in childhood obesity. PARTICIPANTS: 250 obese children. Oral glucose tolerance test was performed, serum glucose and insulin were determined, and HOMA-IR was calculated. RESULTS: Impaired fasting glucose (IFG) was found in 1.2% according to World Health Organisation criteria and 4.4% according to the criteria of the International Diabetes Federation. Impaired glucose tolerance (IGT) was found in 13.6%, type 2 diabetes mellitus (DM2) in 2.4%. Frequency of fasting glucose (FG) above 7.0 mmol/l was 1.2%. Basal hyperinsulinemia was increased in 70%, reactive hyperinsulinemia in 88%, frequency of elevated HOMA-IR was 78%. 120' insulin was increased in all cases with abnormal FG, IGT and DM2, HOMA-IR was elevated in 79% of patients with IGT and all patients with abnormal FG and DM2. Significant positive correlations were demonstrated between body mass index and insulin levels. CONCLUSION: Our data show that hyperinsulinemia can successfully compensate for insulin resistance in the majority of the obese children. Since IFG is less frequent than IGT there is a need for performing OGTT to demonstrate abnormality of glucoregulation in obese children.     

Serum levels of soluble tumor necrosis factor-alpha receptor 2 are linked to insulin resistance and glucose intolerance in children

BACKGROUND: Obesity and insulin resistance are increasingly common problems in children. Tumor necrosis factor-alpha (TNF-alpha) has important effects on lipid and glucose metabolism. This effect may be mediated through soluble TNF-alpha receptor 2 (sTNFR2). OBJECTIVE: To investigate the relationship between insulin resistance and the TNF-alpha system in childhood obesity. CHILDREN AND METHODS: Twenty-one obese and six non-obese children were studied. Body mass index (BMI) z-scores, percent body fat (PBF) and waist to hip ratio (WHR) were determined. Fasting serum levels of total cholesterol, HDL-cholesterol, LDL-cholesterol, TNF-alpha and sTNFR2 were measured. A standard 2-hour oral glucose tolerance test (dose of glucose: 1.75 g/kg, max. 75 g) was done. Insulin resistance (IR) was estimated by fasting plasma insulin, plasma insulin at 120 min, homeostasis model assessment (HOMA) and insulin area under the curve (AUC) from OGTT. Insulin sensitivity was estimated by oral glucose insulin sensitivity (OGIS120). RESULTS: Among the obese participants, one child (5.2%) was found to have diabetes mellitus and four others (21.1%) impaired glucose tolerance (IGT). Obese children had significantly elevated sTNFR2 levels. Furthermore, the group of obese children with IGT and the patient with newly diagnosed diabetes mellitus together (n = 5) had significantly higher levels of serum sTNFR2 (2,865+/-320 pg/ml) than the rest of the obese (2,460+/-352 pg/ml; p = 0.016) or lean (1,969+/-362 pg/ml; p = 0.014) children. Serum sTNFR2 levels correlated positively with insulin AUC, HOMA IR, fasting plasma insulin, plasma insulin at 120 min, total cholesterol and LDL/ HDL ratio, and negatively with OGIS120. Multiple regression analysis revealed that age, WHR, sTNFR2 and LDL predicted 81% of the variability in glucose at 120 min. CONCLUSION: sTNFR2 is a candidate marker of insulin resistance and glucose intolerance.     

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.     

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.     

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。     

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.     

Glucose metabolism disorder in obese children assessed by continuous glucose monitoring system

Background  Continuous glucose monitoring system (CGMS) can measure glucose levels at 5-minute intervals over a few days, and may be used to detect hypoglycemia, guide insulin therapy, and control glucose levels. This study was undertaken to assess the glucose metabolism disorder by CGMS in obese children. Methods  Eighty-four obese children were studied. Interstitial fluid (ISF) glucose levels were measured by CGMS for 24 hours covering the time for oral glucose tolerance test (OGTT). Impaired glucose tolerance (IGT), impaired fasting glucose (IFG), type 2 diabetic mellitus (T2DM) and hypoglycemia were assessed by CGMS. Results  Five children failed to complete CGMS test. The glucose levels in ISF measured by CGMS were highly correlated with those in capillary samples (r=0.775, P<0.001). However, the correlation between ISF and capillary glucose levels was lower during the first hour than that in the later time period (r=0.722 vs r=0.830), and the ISF glucose levels in 69.62% of children were higher than baseline levels in the initial 1–3 hours. In 79 obese children who finished the CGMS, 2 children had IFG, 2 had IGT, 3 had IFG + IGT, and 2 had T2DM. Nocturnal hypoglycemia was noted during the overnight fasting in 11 children (13.92%). Conclusions  Our data suggest that glucose metabolism disorder including hyperglycemia and hypoglycemia is very common in obese children. Further studies are required to improve the precision of the CGMS in children.     

Relationship between different fasting-based insulin sensitivity indices in obese children and adolescents

OBJECTIVES: To evaluate insulin sensitivity from data obtained from baseline values and from an oral glucose tolerance test (OGTT) in normal and obese children and adolescents. STUDY DESIGN: We recruited 89 children 4-10 years old and 82 adolescents 11-18 years old divided into moderately obese (Mod OB), severely obese (Severe OB), and non-obese (Non-OB) controls. We evaluated the relationship between four simple measures of insulin sensitivity: homeostatic model assessment (HOMA-IR), quantitative insulin sensitivity check index (QUICKI), fasting glucose to insulin ratio (FGIR), and fasting insulin resistance index (FIRI), with an insulin sensitivity measure derived from the standard 2-hour OGTT, the composite whole body insulin sensitivity index (ISI Comp). RESULTS: The strongest correlation was between QUICKI and ISI Comp and between FGIR and ISI Comp, (correlations [r] 0.81-0.85 in the Mod OB and 0.63-0.67 in the Severe OB). The relationship between HOMA-IR and ISI Comp and between FIRI and ISI Comp did not appear to be as strong (correlations [r] -0.36 and -0.53 in Mod OB and Severe OB, respectively). Moderately obese and severely obese children had fasting and 2-hour insulin levels 2-3 fold higher than the control group. CONCLUSIONS: QUICKI and FGIR, are strongly correlated with OGTT measures of insulin sensitivity in children and adolescents with different degrees of obesity. These simple fasting-based indices may help the pediatrician identify patients at risk of developing insulin resistance.     

The progression from obesity to type 2 diabetes in Alström syndrome

Bettini V, Maffei P, Pagano C, Romano S, Milan G, Favaretto F, Marshall JD, Paisey R, Scolari F, Greggio NA, Tosetto I, Naggert JK, Sicolo N, Vettor R. The progression from obesity to type 2 diabetes in Alström syndrome. Background: Alström syndrome (ALMS) is a rare autosomal recessive monogenic disease associated with obesity, hyperinsulinemia, and alterations of glucose metabolism that often lead to the development of type 2 diabetes at a young age. Objective: To study the relationship between weight and metabolism in a group of ALMS patients and matched controls. Research design and methods: Fifteen ALMS patients (eight males, seven females; aged 3–51) were compared in a cross‐sectional study with an age‐ and weight‐matched control population. Anthropometric parameters, fat mass, glucose and insulin secretion in basal and dynamic oral glucose tolerance test (OGTT) conditions were measured. Furthermore, anthropometric and body composition data were obtained from an international group of 27 ALMS patients (13 males, 14 females, age range: 4–29 yr). Results: In ALMS we observed an inverse correlation between age and standard deviation scores for height, weight, and body mass index. The OGTT glycemic curves of ALMS subjects were similar to those of age‐matched controls, whereas insulin response was clearly greater. In ALMS individuals the insulin response showed a reduction with age. We documented pathologic values of the derived indices homeostasis model assessment of insulin resistance (HOMA‐IR), insulin sensitivity index, HOMA%β‐cell and insulinogenic index in ALMS, but unlike the insulin‐resistance indices, the β‐cell function indices showed a significant reduction with age. Conclusions: In ALMS the progression from the early onset obesity toward the impaired fasting glucose or impaired glucose tolerance and overt diabetes is mostly because of a progressive failure of β‐cell insulin secretion without any further worsening of insulin resistance with age, even in the presence of weight reduction.     

The prevalence of impaired fasting glucose and type 2 diabetes in a population‐based sample of overweight/obese children in the Middle East

Moadab MH, Kelishadi R, Hashemipour M, Amini M, Poursafa P. The prevalence of impaired fasting glucose and type 2 diabetes in a population‐based sample of overweight/obese children in the Middle East. Background: Type 2 diabetes mellitus (T2DM) and impaired fasting glucose (IFG) are increasing in young population who are facing an escalating trend of overweight. The aim of this study was to determine the prevalence of IFG and T2DM for the first time in a population‐based sample of Iranian obese children. Methods: This cross‐sectional, population‐based study was conducted in Isfahan, the second large city of Iran. Overall, 672 overweight and obese school students, selected from 7554 students, aged 6–19 yr, were screened for IFG and T2DM. Fasting plasma glucose (FPG) and lipid profile were measured in all participants. Oral glucose tolerance test and insulin level were measured in those children with IFG. Insulin resistance was defined as homeostasis model assessment for insulin resistance (HOMA‐IR) > 3.10. Results: Among the7554 students (48.7% boys and 51.3% girls) studied, 9.34% (n = 706) were overweight and 5.3% (n = 403) were obese. A number of 672 overweight and obese students including 302 (44.9%) boys and 370 (55.1%) girls, with a mean age of 12.8 ± 3.10 yr underwent biochemical work up. Overall, the prevalence of IFG was 4.61% (n = 31), the corresponding figure was 2% (n = 4) in the 6–10 yr age group, and 5% (n = 27) in those aged 10.1–19 yr. The prevalence of T2DM was 0.1% (n = 1; age, 18.00 yr). Impaired glucose tolerance and insulin resistance were detected in three and six participants with IFG, who consisted 0.4 and 0.8% of total obese and overweight students, respectively. Conclusions: Although the prevalence of T2DM is low in Iranian obese children, IFG is not uncommon. Preventive measures and screening of FPG should be considered for these children.     

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.     

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 is a reliable cutaneous marker of insulin resistance in obese Japanese children

BACKGROUND: Acanthosis nigricans (AN) is a skin condition characterized by darkening and thickening of skin with formation of irregular folds, usually limited to a few specific areas of the body. Recently, AN has been reported to be linked to hyperinsulinemia and obesity. The aim of the present study was to determine whether or not the presence of AN in obese Japanese children is a reliable cutaneous marker. METHODS: The authors analyzed the clinical characteristics of 439 obese Japanese children (260 boys, 179 girls; mean age 10.1 years; mean percentage overweight 51.9%), who had visited Tsuruoka City Shonai Hospital in 1990-2000. Eighty-two of the 439 children were examined using an oral glucose tolerance test (OGTT). Of these children, the authors retrospectively studied 16 subjects: eight with AN and eight without AN (age range: 10.8-13.9 years; percentage overweight range: 54.3-97.0%). They were age and percentage obesity-matched males with normal glucose tolerance during OGTT. Females with normal glucose tolerance during OGTT were excluded from the 16 subjects because the number was too small and children with impaired glucose tolerance or type 2 diabetes during OGTT were also excluded because of glucose toxicity. Eighty-two children including the 16 subjects were analyzed at their first visit for the presence or absence of AN on the posterior of the neck, and for characteristics including age, birthweight, body height, bodyweight, percentage overweight, blood pressure, liver function markers serum lipid concentrations, fasting plasma glucose concentrations and insulin concentrations shown by the results of OGTT. RESULTS: (1) Children with AN showed significantly more glucose intolerance including impaired glucose tolerance and type 2 diabetes compared with those children without AN, and fasting plasma insulin concentrations were most significantly correlated with the presence of AN. (2) Insulin resistance based on fasting plasma insulin concentrations was seen in significantly more children with AN than in children without AN, even in age and percentage obesity-matched subjects with normal glucose tolerance during OGTT. CONCLUSIONS: Acanthosis nigricans could be a reliable cutaneous marker of insulin resistance in obese Japanese children.     

The absence of insulin resistance in metabolic syndrome definition leads to underdiagnosing of metabolic risk in obese patients

This study explores in a group of obese children and adolescents aged 10 to 16 years, the prevalence of metabolic syndrome (MS) according to the criteria of International Diabetes Federation (IDF). In addition, the prevalence of insulin resistance (IR) was investigated to find correlations between MS and IR. IDF definition was compared to a modified WHO definition. A total of 159 obese patients (74 male and 85 female; median age 12.7 years) were included in the study. Anthropometric measurements, blood pressure, and serum fasting lipids were evaluated. An oral glucose tolerance test (OGTT) was performed, and serum glucose and insulin levels were measured at 0, 30, 60, 90, and 120 min. Homeostasis model assessment of insulin resistance (HOMA-IR), quantitative insulin sensitivity check index (QUICKI), fasting glucose/insulin ratio (FGIR), Matsuda index, and total insulin levels during OGTT were calculated. For the IR diagnosis, we used cutoff values described in previous publications (HOMA-IR of >3.16, QUICKI of <0.357, FGIR of <7, and/or the sum of insulin levels during OGTT of >300 mIU/mL). MS prevalence, defined according to IDF criteria, was 34.6 %. Using the IDF definition, there was no statistically significant difference for the surrogate IR indices between patients with or without MS (QUICKI, 94.5 vs. 83.7 %), FGIR (81.1 vs. 78.8 %), HOMA-IR (70.9 vs. 63.5 %), and total insulin levels during OGTT (61.8 vs. 51.9 %). The Matsuda index values, the prevalence of fasting hyperinsulinemia, and impaired glucose tolerance were also similar in these two groups. In conclusion, IR was prominent in obese patients with and without MS. IDF definition of MS fails to discover individuals with IR, unless it is specifically investigated.     

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。     

Elevated fasting triglycerides predict impaired glucose tolerance in adolescents at risk for type 2 diabetes

OBJECTIVE: The aim of this study was to evaluate whether fasting laboratory values can predict impaired glucose tolerance (IGT) in adolescents who are at risk for developing type 2 diabetes mellitus (T2DM). HYPOTHESIS: Elevated fasting triglycerides, a marker for worsening insulin resistance, predict risk for IGT. DESIGN: Following a fast of at least 9 h, laboratory measures, body mass index (BMI), and demographic information were obtained. The subjects then underwent a 75-g oral glucose challenge with a 2-h postchallenge glucose determination. SUBJECTS: Eighty-four adolescents aged 12-20 yr with at least two risk factors for developing T2DM (obesity, family history of T2DM, or acanthosis nigricans) and with either a fasting insulin level > or =25 microU/mL or a homeostasis model assessment of insulin resistance (HOMA-IR) > or =3.5 were recruited for the study. RESULTS: Ten subjects (12%) had IGT [2-h glucose > or =140 mg/dL (7.77 mmol/L)], and 10 subjects (12%) had impaired fasting glucose [IFG; fasting glucose > or =100 mg/dL (5.55 mmol/L)]. However, only three (30%) subjects with IGT had IFG, though all subjects with IGT had a fasting triglyceride level > or =150 mg/dL (1.70 mmol/L). Of those subjects with elevated triglycerides, 29% had IGT. As a screening test to predict risk for IGT, elevated triglycerides >150 mg/dL had a sensitivity of 100% and a specificity of 68%. The positive predictive value was 29%, and the negative predictive value was 100%. CONCLUSIONS: Screening with fasting glucose alone would have missed 70% of subjects with IGT in this population of insulin-resistant adolescents. However, a fasting triglyceride level > or =150 mg/dL was strongly associated with IGT and may help to identify at-risk adolescents who should undergo formal glucose tolerance testing.     

Glucose Tolerance in Overweight and Obese North Indian Adolescents

The present analytic study was planned to study the impact of overweight and obesity on glucose tolerance in adolescents. Thirty overweight (BMI analogue ≥ 25–29.9 kg/m²) and 30 obese (BMI analogue ≥ 30 kg/m²) adolescents were included as cases and 30 healthy age and sex matched adolescents comprised the control group. All the study participants were subjected to oral glucose tolerance test (OGTT) as a measure of glucose tolerance.Means of fasting blood glucose levels in normal, overweight and obese groups were 84.5 mg/dl, 86.7 mg/dl and 94.8 mg/dl respectively. Means of two hourly blood glucose levels in normal, overweight and obese groups were 105.8 mg/dl, 117 mg/dl and 127.1 mg/dl respectively. Oral Glucose tolerance test (OGTT) was normal in all the participants from control group but was impaired in four overweight adolescents. In obese group, OGTT was impaired in eight subjects and one obese child had fasting and 2 hourly blood glucose levels in diabetic range.     

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.