Objective This study aimed to identify high?risk groups for metabolic syndrome(MS)among Chinese children and adolescents by calculating the cutoff values of adiposity measures and insulin resistance(IR). Methods From December 2010 to January 2011,data from 933 Chinese subjects(492 boys and 436 girls,aged 11?16 years)from Liaoyang City,China,were included. Questionnaires were administered,and da?ta such as anthropometric parameters(height,waist circumference,and hip circumference),blood pressure,fasting blood glucose level,blood lip?id level,serum uric acid level,and fasting insulin level were collected. Receiver?operating characteristic(ROC)curve analysis was used to deter?mine the optimal cutoff waist?to?height ratio(WHtR),waist?to?hip ratio(WHR),homeostasis model assessment?insulin resistance(HOMA?IR) index,triglyceride level,glucose index(TyG index),and serum uric acid(SUA)level for identification of children and adolescents with MS. Results The AUC of WHtR,WHR,TyG index,HOMA?IR index,and SUA level were larger than 0.5,with P values of<0.01. The optimal cutoff WHtR and WHR derived from the ROC analysis were respectively 0.48(87.0%,84.1%)and 0.84(83.3%,70.3%)for boys and 0.46(95.1%, 81.8%)and 0.80(90.5%,71.8%)for girls. Conclusion This study demonstrated that WHtR and WHR are useful predictive markers of MS , while HOMA?IR,TyG index,and SUA level are not. The usefulness of these criteria needs to be verified by further evaluation.

Objective To evaluate the performance of HbA1C in diagnosis of pre-diabetes in Chinese adolescents.Methods A total of 933 students(aged 13-16 year,46.5% female)without known history of diabetes were selected from junior and senior middle schools in Liaoyang city.HbA1C and fasting plasma glucose(FPG)levels were determined in all participants.Pre-diabetes was diagnosed as according to 2010 American Diabetes Association (ADA)criteria[HbA1C 5.7%-6.4%,FPG(5.6-6.9)mmol/L].The individuals with HbA1C ≥5.7% underwent oral glucose tolerance test(OGTT)and were classified into impaired glucose tolerance(IGT)and impaired fasting glucose(IFG)according to 1999 World Health Organization(WHO)criteria.The performance of HbA1C in diagnosing pre-diabetes by the new criteria was evaluated by the traditional OGTT results based on receiver operating characteristic(ROC)curves.Results Among all participants,213(22.8%)individuals were diagnosed as prediabetic subjects.72.3% of individuals with pre-diabetes were identified by HbA1C alone,23.0% by FPG alone,and only 4.7% by both tests simultaneously.The ROC curve for HbA1C to identify impaired fasting glucose diagnosed by new criteria had an area under the curve(AUC)of 0.50 without statistical significance(P = 0.97).Of the 164 participants with HbA1C 5.7% -6.4%,68 individuals received OGTT,among which 18 subjects were diagnosed as IGT(n= 14)or IFG(n = 4).The ROC curve for HbA1C to identify pre-diabetes diagnosed by OGTT had an AUC of 0.53,without statistical significance(P = 0.69).Conclusion In Chinese adolescents,HbA1C is not suitable for diagnosis or screening of pre-diabetes.

Objective To evaluate the differences and consistency of different diagnostic criteria for metabolic syndrome ( MetS ) in adolescents. Methods This cross-sectional study enrolled 920 healthy middle school students (aged11-16years,53.2% males). All participants underwentant hropometric and biochemical examinations,andwere diagnosed as MetS separately using criterion of the Pediatric Academy of Chinese Medical Association ( abbreviated as Chinese criterion) , 2007 International Diabetes Federation criterion ( IDF criterion) , and Cook criterion based on the National Cholesterol Education Program-Adult Treatment Panel in 2003 ( Cook criterion) . Statistic analysis was used to compare the prevalence of MetS diagnosed and the individual MetS components detected by the different diagnostic criteria, and to evaluate the differences and consistency between the three criteria. Results The prevalence of MetS diagnosed with the Cook criterion (16. 2%) was significantly higher than that by the Chinese criterion(11. 0%) and the IDF criterion. The most frequently detected components were low high-density with the Chinese criterion and IDF criterion, hypertension with the Cook criterion. The least frequently detected component was hyperglycemia with each criterion. The consistency was found stronger between the Chinese and IDF criteria ( Kappa=0. 798-0. 829, P<0.01), but weak between the Cook and the other two criteria (Kappa=0. 465-0. 789,P<0. 01). The adolescents solely diagnosed as MetS patients by the Cook criterion but not the other two criteria had more central obesity, higher plasma glucose and lipid levels and HOMA insulin resistance index (all P<0. 05). Conclusion The prevalence of MetS and components diagnosed with the three criteria was evidently different. The Cook criterion may diagnose more adolescents with higher cardiovascular risks and insulin resistance.