Objective Central obesity is considered to be a central component of metabolic syndrome. Waist circumference (WC) has been widely used as a simple indicator of central obesity. This study is aimed to evaluate the sensitivity of WC cut-off values for predicting metabolic risk factors in middle-aged Chinese.
Methods The study involved 923 subjects aged 40-65 years. The metabolic risk factors were defined according to the Chinese Joint Committee for Developing Chinese Guidelines on Prevention and Treatment of Dyslipidemia in Adults. WC cut-off 85-90 cm and≥90 cm were used as cut-off values of central pre-obesity and central obesity in males, respectively, while WC 80-85 cm and≥85 cm were used as cut-off values of central pre-obesity and central obesity in females.
Results First, WC values corresponding to body mass index (BMI) 24 kg/m2 and visceral fat area (VFA) 80 cm2 were 88.55 cm and 88.51 cm in males, and 81.46 cm and 82.51 cm in females respectively. Second, receiver operating characteristic curves showed that the optimal WC cut-off of value was 88.75 cm in males, higher than that in females (81.75 cm). Third, the subjects with higher WC values were more likely to have accumulating metabolic risk factors. The prevalence of metabolic risk factors increased linearly and significantly in relation to WC levels.
Conclusion WC cut-off values of central pre-/central obesity are optimal to predict multiple metabolic risk factors.

Objective Obesity is becoming a worldwide health problem. The genome wide association (GWA) study particularly for body mass index (BMI) has not been successfully conducted in the Chinese. In order to identify novel genes for BMI variation in the Chinese, an initial GWA study and a follow up replication study were performed.
Methods Affymetrix 500K SNPs were genotyped for initial GWA of 597 Northern Chinese. After quality control, 281 533 SNPs were included in the association analysis. Three SNPs were genotyped in a Southern Chinese replication sample containing 2 955 Chinese Han subjects. Association analyses were performed by Plink software.
Results Eight SNPs were significantly associated with BMI variation after false discovery rate (FDR) correction (P=5.45×10-7-7.26×10-6, FDR q=0.033-0.048). Two adjacent SNPs (rs4432245 &rs711906) in the eukaryotic translation initiation factor 2 alpha kinase 4 (EIF2AK4) gene were significantly associated with BMI (P=6.38×10-6&4.39×10-6, FDR q=0.048). In the follow-up replication study, we confirmed the associations between BMI and rs4432245, rs711906 in the EIF2AKE gene (P=0.03&0.01, respectively).
Conclusion Our study suggests novel mechanisms for BMI, where EIF2AK4 has exerted a profound effect on the synthesis and storage of triglycerides and may impact on overall energy homeostasis associated with obesity. The minor allele frequencies for the two SNPs in the EIF2AK4 gene have marked ethnic differences between Caucasians and the Chinese. The association of the EIF2AK4 gene with BMI is suggested to be‘ethnic specific’ in the Chinese.

Objective Calibrated Automated Thrombogram(CAT) is a test to monitor the generation of thrombin. It can be described by four parameters:lag time, peak thrombin, endogenous thrombin potential (ETP) and time to peak (ttPeak). This study aims to determine the normal ranges of CAT parameters in Chinese, and evaluate whether thrombin generation is correlated with the concentration of heparin/low molecular weight heparin.
Methods Plasma from 120 healthy subjects were collected to determine the normal rangea of CAT parameters in Chinese. Normal plasma pool (NPP, n=25) spiked with different concentrations of heparin or enoxaparin were used to detecte CAT parameters. The overall and age specific normal ranges of CAT parameters were calculated using descriptive statistics method with mean±2SD. The correlation between CAT parameters and age or concentrations of heparin, enoxaparin were analyzed with linear regression model.
Results The normal ranges for lag time, peak thrombin, ETP, ttPeak in the subjects were 3.648±2.465 min, 367.39±151.93 nmol/L, 2277±1030 nmol/L·min and 6.372±4.280 min respectively. Age was linearly correlated with lag time (r=-0.6583, P<0.0001), peak thrombin (r=0.4863, P<0.0001), ETP (r=0.3608, P<0.0014) and ttPeak (r=-0.6313, P<0.0001). The values of ETP/peak ratio were linearly correlated with concentrations of heparin.
Conclusion The normal ranges of four CAT parameters for Chinese were determined. CAT parameters are associated with age. ETP/peak ratio could be used to monitor the process of anticoagulation therapy.

Objective Waist circumference, as a brief indicator of visceral obesity, is associated with multi-metabolic disorders and cardiovascular diseases. The present study was aimed to find out the relationship between waist circumference and carotid intima media thickness (C-IMT), as well as the best waist circumference cutoff for identifying C-IMT elevation in Chinese male patients with newly-diagnosed diabetes.
Methods Five hundred and seventy-eight patients from Department of Endocrinology and Metabolism in Shanghai Sixth People’s Hospital affiliated to Shanghai Jiao Tong University were enrolled. Both physical examination (for measurement of waist circumference) and carotid ultrasonography (for measurement of C-IMT) were performed.
Results After grouping according to the quartiles of C-IMT, the waist circumference increased across all its quartiles. The waist circumference in 3rd and 4th quartiles (90.7±9.8 cm and 90.8±9.6 cm) was significant higher than in 1st and 2nd quartiles (P<0.05). When subjects were divided into 4 groups according to waist circumference, the C-IMT of subjects with waist circumference 90-95 cm was significant higher than that of subjects with waist circumference 85-90 cm and less than 85 cm respectively (P<0.05). Both spearman and partial correlation analysis showed that C-IMT was positively correlated with waist circumference (P<0.01). C-IMT was found significantly elevated with the increase of waist circumference. Multiple stepwise regression analysis showed that waist circumference was one of the independent risk factors of C-IMT. After an average of 2.23±0.85 years follow up, there was a significant elevation of C-IMT in the group with baseline waist circumference over 90 cm P<0.05), while no significant difference was detected in the group with baseline waist circumference less than 90 cm (P=0.27). Logistic regression showed that baseline waist circumference over 90 cm was associated with a relative risk to C-IMT elevation of 1.132 (95%CI 1.043-1.431, P<0.05).
Conclusion Among newly-diagnosed diabetic male patients, waist circumference over 90 cm not only reflects sub-clinical atherosclerosis in early stage, but also predicts the progression of atherosclerosis.

Objective To study the effectiveness of waist circumference cut-off values in predicting the prevalence of metabolic syndrome (MetS) and risk factors in adults in China.
Methods A cross-sectional survey was condcuted in 14 provinces (autonomous region, municipality) in China. A total of 47 325 adults aged ≥20 years were selected by multistage stratified sampling, and questionnaire survey and physical and clinical examination were conducted among them. MetS was defined according to the International Diabetes Federation (IDF) criteria and modified IDF criteria.
Results The age-standardized prevalence of MetS was 24.2%(22.1%in men and 25.8%in women) and 19.5% (22.1% in men and 18.0% in women) according to the IDF criteria and modified IDF criteria respectively. The age-standardized prevalence of pre-MetS was 8.1%(8.6%in men and 7.8%in women) according to the modified IDF criteria. The prevalence of MetS was higher in urban residents than rural residents and in northern China residents than in southern China residents. The prevalence of central obesity was about 30% in both men and women according to the ethnicity-specific cut-off values of waist circumference for central obesity (90 cm for men and 85 cm for women). Multivariate regression analysis revealed no significant difference in risk factors between the two MetS definitions.
Conclusion Using both the modified IDF criteria and ethnicity-specific cut-off values of waist circumference can provide more useful information about the prevalence of MetS in China.

Objective To study the optimal waist circumference (WC) cut-off values for identifying metabolic risk factors in middle-aged and elderly subjects in Shandong Province of China.
Methods A total of 2 873 men and 5 559 women were included in this cross-sectional study. Metabolic syndrome (MetS) was diagnosed according to the definition of Chinese Diabetes Society in 2004. The relation between WC and MetS was analyzed by multivariate logistic regression analysis. The optimal WC cut-off values were identified using the area under the ROC curve and the different diagnostic criteria for central obesity were compared.
Results The WC was the risk factor for MetS independent of BMI, blood glucose, blood lipid, and blood pressure. The optimal WC cut-off value was 83.8 cm and 91.1 cm for identifying MetS in women and men, respectively. Compared with 80 cm and 85 cm for women and men, 85 cm and 90 cm had a higher Youden index for identifying all metabolic risk factors and MetS in women and men.
Conclusion The appropriate WC cut-off value is 85 cm and 90 cm for identifying central obesity and MetS in women and men in Shandong Province of China.

Objective To compare the blood antioxidant levels and dietary antioxidant intakes between pilots and non-flight staff of the Army Force in The Islamic Republic of Iran.
Methods Thirty-seven helicopter pilots and 40 non-flight staff were included in this study. Their general characteristics were recorded and their weight, height, and waist circumference were measured. Their daily intake of energy and nutrients including antioxidants was assessed using a semi-quantitative food frequency questionnaire. Serum levels of total antioxidant capacity (TAC), malondialdehyde (MDA), and glutathione reductase (GR), glutathione peroxidase (GPx), superoxide dismutase (SOD), and catalase (CAT) in red blood cells were also measured.
Results The median erythrocytes SOD, serum MDA level and the mean serum level of TAC and erythrocytes GPx were significantly higher in pilots than in non-flight staff. The median vitamin C intake was significantly lower in pilots than in non-flight staff. The serum MDA levels were similar in non-flight staff and pilots when their vitamin C intake was≤168 mg and significantly lower in non-flight staff than in pilots when their vitamin C intake was>168 mg.
Conclusion The serum MDA level is lower in non-flight staff than in pilots when their vitamin C intake level is high, indicating that pilots need more vitamin C than non-flight staff.