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 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 relative risk of waist circumference (WC) and/or BMI on cardiovascular risk factors. Methods A cross-sectional data of 41 087 adults (19 567 male and 21 520 female) from the 2002 China National Nutrition and Health Survey were examined. According to the obesity definition of WGOC (BMI, 24 kg/m2 and 28 kg/m2; WC, male 85 cm and 95 cm for male, 80 cm and 90 cm for female), the study population were divided into 9 groups. The prevalence and odds ratio (Ors) of cardiovascular disease (CVD) risk factors (hypertension, high fasting plasma glucose and dyslipidemia) were compared among these 9 groups. Stepwise linear regression analyses were used to compare the likelihood of BMI and/or WC on CVD risk factors. Results Both the indexes levels and the odds ratios of CVD risk factors were significantly increased (decreased for HDL-C levels) along with the increase of WC and/or BMI, even when the effect of age, sex, income, education, sedentary activity and dietary factors were adjusted. The variances (R2) in CVD risk factors explained by WC only and BMI only were quite similar, but a little bit larger when WC and BMI were combined. The standard β was higher of BMI when predicting systolic BP and was higher of WC when predicting TG, TC and HDL. Conclusions BMI and WC had independent effects on CVD risk factors and combination of BMI and WC would be more predictive. Findings from the present study provided substantive evidence for the WGOC recommendation of a combined use of BMI and WC classifications.

研究韩国人良性前列腺增生患者的肥胖症对下尿道综合症的影响