Predictive Ability of Hypertriglyceridemic Waist,Hypertriglyceridemic Waist-to-Height Ratio,and Waist-to-Hip Ratio for Cardiometabolic Risk Factors Clustering Screening among Chinese Children and Adolescents

Objective Hypertriglyceridemic waist(HW),hypertriglyceridemic waist-to-height ratio(HWHtR),and waist-to-hip ratio(WHR)have been shown to be indicators of cardiometabolic risk factors.However,it is not clear which indicator is more suitable for children and adolescents.We aimed to investigate the relationship between HW,HWHtR,WHR,and cardiovascular risk factors clustering to determine the best screening tools for cardiometabolic risk in children and adolescents.Methods This was a national cross-sectional study.Anthropometric and biochemical variables were assessed in approximately 70,000 participants aged 6–18 years from seven provinces in China.Demographics,physical activity,dietary intake,and family history of chronic diseases were obtained through questionnaires.ANOVA,χ2 and logistic regression analysis was conducted.Results A significant sex difference was observed for HWHtR and WHR,but not for HW phenotype.The risk of cardiometabolic health risk factor clustering with HW phenotype or the HWHtR phenotype was significantly higher than that with the non-HW or non-HWHtR phenotypes among children and adolescents(HW:OR=12.22,95%CI:9.54-15.67;HWHtR:OR=9.70,95%CI:6.93-13.58).Compared with the HW and HWHtR phenotypes,the association between risk of cardiometabolic health risk factors(CHRF)clustering and high WHR was much weaker and not significant(WHR:OR=1.14,95%CI:0.97-1.34).Conclusion Compared with HWHtR and WHR,the HW phenotype is a more convenient indicator with higher applicability to screen children and adolescents for cardiovascular risk factors.

Smooth Trajectory Planning for a Cable Driven Parallel Waist Rehabilitation Robot Based on Rehabilitation Evaluation Factors

Rehabilitation robots can help physiatrists to assist patients in improving their movement ability.Due to the interaction between rehabilitation robots and patients,the robots need to complete rehabilitation training on a safe basis.This paper presents an approach for smooth trajectory planning for a cable-driven parallel waist rehabilitation robot(CDPWRR)based on the rehabilitation evaluation factors.First,motion capture technology is used to collect the motion data of several volunteers in waist twisting.Considering the impact of motion variability,the feature points at the center of the human pelvis are obtained after eliminating unreasonable data through rationality judgments.Then,point-to-point waist training trajectory planning based on quintic polynomial and cycloid functions,and multipoint waist training trajectory planning based on quintic B-spline functions are carried out.The corresponding planned curves and kinematics characteristics using three methods are compared and analyzed.Subsequently,the rehabilitation evaluation factors are introduced to conduct smooth trajectory planning for waist training,and the waist trajectory with better compliance is obtained based on the safety and feasibility of waist motion.Finally,the physical prototype of the CDPWRR is built,and the feasibility and effectiveness of the proposed smooth trajectory planning method are proved by numerical analysis and experiments.

A Cross Sectional Study on the Correlation between Waist Circumference and Fatty Liver on Ultrasonography among Non-Alcoholic Filipino Adults

Objectives: This study aimed to determine the correlation between waist circumference and fatty liver on ultrasonography among non-alcoholic Filipino adults. This will aid in detecting non-alcoholic fatty liver disease in its early course, hence improving our current therapeutic recommendations in preventing and managing the adverse health outcomes of NAFLD. Methods and Materials: A cross-sectional study with a total of 65 recruited participants. The data collected were age, sex, waist-circumference, co-morbidities with maintenance medications, history of alcohol intake with emphasis on the quantity and duration, and history of drug intake. Waist circumference was measured and recorded. The presence of NAFLD was determined through a review of the ultrasonography results of all subjects. The demographic profile and waist circumference of all subjects were described using descriptive statistics. The chi-square test was utilized to test the independence of the NAFLD and WC in the quartile. Pearson correlation was used to determine the linear relationship between the variables. Pearson correlation coefficient was statistically significant at p 0.05. Results: Among the subjects, 26 (42%) presented with fatty liver based on ultrasonography, 15 (58%) and 11 (42%), males and females, respectively. The mean waist circumference of 97.5 ± 12.43 was significantly related to the fatty liver with a p-value of 0.0001. Waist circumference showed a positive correlation with the frequency of fatty liver on ultrasonography with p-values of 0.000755 (r = 0.590083) and 3.04366E—05 (r = 0.659143523), in males and females, correspondingly. The overall correlation between waist circumference and fatty liver on ultrasonography is statistically significant with a p-value of 4.10503E—08 (r = 0.634737127). Conclusion: One measure used to assess central obesity is waist circumference. In addition, it can also be utilized to assess risk for NAFLD since they are strongly correlated as reported in this study. Waist circumference cut-off values for the Filipinos proposed in this study are the following: >88 cm and >95 cm, in males and females, respectively.

Predictive Values of Body Mass Index and Waist Circumference for Risk Factors of Certain Related Diseases in Chinese Adults - Study on Optimal Cut-off Points of Body Mass Index and Waist Circumference in Chinese Adults

Objective For prevention of obesity in Chinese population, it is necessary to definethe optimal range of healthy weight and the appropriate cut-off points of BMI and waistcircumference for Chinese adults. The Working Group on Obesity in China under the supportof International Life Sciences Institute Focal Point in China organized a meta-analysis on therelation between BMI, waist circumference and risk factors of related chronic diseases (e. g.,high diabetes, diabetes mellitus, and lipoprotein disorders). Methods 13 population studiesin all met the criteria for enrollment, with data of 239 972 adults (20-70 year) surveyed inthe 1990s. Data on waist circumference was available for 111411 persons and data on serumlipids and glucose were available for more than 80 000. The study populations located in21provinces, municipalities and autonomous regions in China's Mainland as well as inTaiwan. Each enrolled study provided data according to a common protocol and uniformformat. The Center for data management in Department of Epidemiology, Fu Wai Hospitalwas responsible for statistical analysis. Results and conclusion The prevalence ofhypertension, diabetes, dyslipidemia and clustering of risk factors all increased withincreasing levels of BMI or waist circumference. BMI at 24 with best sensitivity andspecificity for identification of the risk factors, was recommended as the cut-off point foroverweight, BMI at 28 which may identify the risk factors with specificity around 90 % wasrecommended as the cut-off point for obesity. Waist circumference beyond 85 cm for menand beyond 80 cm for women were recommended as the cut-off points for central obesity.Analysis of population attributable risk percent illustrated that reducing BMI to normalrange (<24) could prevent 45%-50% clustering of risk factors. Treatment of obese persons(BMI≥28)with drugs could prevent 15%-17% clustering of risk factors. The waistcircumference controlled under 85 cm for men and under 80 cm for women, could prevent47%-58% clustering of risk factors. According to these, a classification of overweight andobesity for Chinese adults is recommended.

Waist Circumference Distribution of Chinese School-age Children and Adolescents

Background Waist circumference （WC）, a proxy measure of central body fat, is a better predictor than overall body fat for cardiovascular risk factors in both adults and children. WC cutoffs have been established in many countries, but the national WC reference has not been developed in China. Objective To study the distribution of WC in a representative group of Chinese children for establishing Chinese WC cutoff points. Methods Cross-sectional data obtained from 15 mainland provinces and Hong Kong were collected. There were 160 225 children and adolescents aged 7-18 years old in total. The subjects were divided into five regional groups namely costal city, other city, noah rural, south rural, and Hong Kong, for analyzing the distribution of WC. Results A large variation in WC distribution was found among the five groups for both sexes. Coastal city group had the highest P85 WC values consistently from the early school ages to 18-year-old compared with other groups. In contrast, south rural group had P85 values consistently lagged behind not only the city groups but also the north rural group. Hong Kong group had a high P85 WC at early ages, but because of the smaller increments of WC during adolescence, the P85 curve was gradually exceeded by the north rural groups. Catch-up trend was found in the two rural groups since the peak of puberty. These disparities were caused by not only socioeconomic and urban-rural factors but also north-south differences. Because of the regional variation of WC, a ＂gradient＂ prevalence of central obesity was prospected among these groups. Comparisons of WC distributions between the Chinese and the U.S.A or Netherlands demonstrated the necessary of setting up China＇s own WC cutoffs. Sex and age-specific percentiles were obtained and smoothed by using LMS method. Conclusion The data obtained from this study could be used to develop national WC cutoff points for Chinese children and adolescents.

Waist Circumference Reference Values for Screening Cardiovascular Risk Factors in Chinese Children and Adolescents

Objectives To explore the optimal threshold values of waist circumference （WC） for detecting cardiovascular （CV） risk factors among Chinese children and adolescents. Methods Association of WC with CV risk factors was studied among 65 898 children aged 7-18 years whose data were pooled from nine previous studies in China. CV risk factors in this study included hypertension （blood pressure above 95 percentile levels）, dyslipidemia （with one or more of the following three indexes： TG ≥ 1.7 mmol/L, TC ≥ 5.18 mmol/L, and HDL-C ≤ 1.04 mmol/L） and elevated glucose level （fasting plasma glucose ≥5.6 mmol/L）. Receive-operating characteristic analysis （ROC） and logistic regression were employed to derive optimal age- and sex-specific waist circumference references for predicting CV risk factors. Results A slight increasing trend of CV risk factors was observed starting from the 75th percentile of waist circumference in the study population, while a remarkable increasing trend occurred from the 90th percentile. The optimal waist circumference thresholds for predicting high blood pressures were at the 75th percentile for both boys and girls, which was at the 90th percentiles for detecting at least two of the above three CV risk factors. In comparison with children with waist circumference below the 75th percentile, the odds ratio of two CV risk factors doubled among children with waist circumference between the 75th and the 90th percentile, and increased by 6 times among children with waist circumference above the 90th percentile. The trend of high blood pressure increasing with waist circumference remained significant after having been stratified by BMI category. Conclusion The 75th and the 90th percentiles of WC are the optimal cut-off points for predicting an increased and a substantially increased risk of CV factors in Chinese children and adolescents, respectively.

Effectiveness of Different Waist Circumference Cut-off Values in Predicting Metabolic Syndrome Prevalence and Risk Factors in Adults in China

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.

Visceral Fat Area,Waist Circumference and Metabolic Risk Factors in Abdominally Obese Chinese Adults

Objective To examine the association of visceral adiposity as measured by VFA and WC with lipid and glucose metabolic biomarkers in abdominally obese Chinese adults,and to assess whether WC could be an indicator of visceral fat.Methods WC and VFA were measured in 155 overweight and obese adults.A fasting blood sample was collected from participant（n=118） whose VFA ≥100 cm2 for analyses of lipid and glucose profile.The relationship between VFA and WC and biomarkers was investigated.Results WC and VFA were significantly interrelated.The coincidence rate of abdominal obesity determined by Japanese VFA and Chinese WC criteria increased across age quartiles in women from 51.7% to 96.2%.A large WC was associated significantly with low HDL-cholesterol concentration（P0.01） and the association was weakened by additional control of VFA.WC and VFA were positively associated with glucose,hemoglobin A1c and insulin concentrations（P0.05 except for the association of VFA with insulin：P0.01）,and all the associations were not significant by additional control of either WC or VFA.As WC quartiles increased,significant stepwise increments in triglyceride,glucose,hemoglobin A1c and insulin and descent in HDL-cholesterol were observed.However,triglyceride and HDL-cholesterol were not significantly different when compared across VFA quartiles.Conclusion Higher visceral fat was associated with an adverse lipid and glucose profile.WC can be a moderate predictor for visceral fat and provides a feasible measurement to estimate glucose metabolic risks.Further studies are warranted to establish age-specific WC cutoffs.

Fatty liver index vs waist circumference for predicting non-alcoholic fatty liver disease

AIM: To determine the discriminatory performance of fatty liver index (FLI) for non-alcoholic fatty liver disease (NAFLD).METHODS: The data of 5052 subjects aged over 18 years were analyzed. FLI was calculated from body mass index, waist circumference (WC), triglyceride, and gamma glutamyl transferase data. Logistic regression analysis was conducted to determine the association between FLI and NAFLD. The discriminatory performance of FLI in the diagnosis of NAFLD was evaluated by receiver operating characteristic analysis. Area under the curves (AUCs) and related confidence intervals were estimated. Optimal cutoff points of FLI in the diagnosis of NAFLD were determined based on the maximum values of Youden&#x02019;s index.RESULTS: The mean age of men and women in the study population were 44.8 &#x000b1; 16.8 and 43.78 &#x000b1; 15.43, respectively (P = 0.0216). The prevalence of NAFLD was 40.1% in men and 44.2% in women (P &#x0003c; 0.0017). FLI was strongly associated with NAFLD, so that even a one unit increase in FLI increased the chance of developing NAFLD by 5.8% (OR = 1.058, 95%CI: 1.054-1.063, P &#x0003c; 0.0001). Although FLI showed good performance in the diagnosis of NAFLD (AUC = 0.8656 (95%CI: 0.8548-0.8764), there was no significant difference with regards to WC (AUC = 0.8533, 95%CI: 0.8419-0.8646). The performance of FLI was not significantly different between men (AUC = 0.8648, 95%CI: 0.8505-0.8791) and women (AUC = 0.8682, 95%CI: 0.8513-0.8851). The highest performance with regards to age was related to the 18-39 age group (AUC = 0.8930, 95%CI: 0.8766-0.9093). The optimal cutoff points of FLI were 46.9 in men (sensitivity = 0.8242, specificity = 0.7687, Youden&#x02019;s index = 0.5929) and 53.8 in women (sensitivity = 0.8233, specificity = 0.7655, Youden&#x02019;s index = 0.5888).CONCLUSION: Although FLI had acceptable discriminatory power in the diagnosis of NAFLD, WC was a simpler and more accessible index with a similar performance.

Are body mass index and waist circumference significant predictors of diabetes and prediabetes risk: Results from a population based cohort study

AIM To determine the predictive role of body mass index(BMI) and waist circumference(WC) for diabetes and prediabetes risk in future in total sample as well as in men and women separately. METHODS In a population based cohort study, 1765 with mean ± SD age: 42.32 ± 6.18 healthy participants were followed up from 2003 till 2013(n = 960). Anthropometric and biochemical measures of participants were evaluated regularly during the follow up period. BMI and WC measures at baseline and diabetes and prediabetes status of participants at 2013 were determined. Multivariable logistic regression analysis was used for determining the risk of diabetes and prediabetes considering important potential confounding variables. Receiver operatingcharacteristic curve analysis was conducted to determine the best cut of values of BMI and WC for diabetes and prediabetes. RESULTS At 2013, among participants who had complete data, 45 and 307 people were diabetic and prediabetic, respectively. In final fully adjusted model, BMI value was a significant predictor of diabetes(RR = 1.39, 95%CI: 1.06-1.82 and AUC = 0.68, 95%CI: 0.59-0.75; P < 0.001) however not a significant risk factor for prediabetes. Also, WC was a significant predictor for diabetes(RR = 1.2, 95%CI: 1.05-1.38 and AUC = 0.67, 95%CI: 0.6-0.75) but not significant risk factor for prediabetes. Similar results were observed in both genders.CONCLUSION General and abdominal obesity are significant risk factors for diabetes in future.

Correlation between Waist Circumference and Carotid Intima-Media Thickness in Women from Shanghai, China

Objective To evaluate whether waist circumference （WC） 〉85 cm is related to asymptomatic preclinical atherosclerosis in women from Shanghai, China. Methods A total of 2365 females aged 〉20 years recruited from 4 communities underwent physical examination and carotid artery scanning. Their carotid intima-media thickness （C-iMT） was measured. Results The C-IMT was significantly higher in overweight or obese women with their BMI 〉25.0 kg/m2 {P〈O.01） and in those with their WC _〉85 cm than in those with their WC 〈85 cm （P〈O.01）. Spearman and partial correlation analysis showed that the C-IMT was significantly correlated with WC which was independent of menopausal status. The C-IMT significantly increased with the increasing WC and reached to a platform in about 85 cm. An increment tendency was found in the subgroup with its WC 〈 85 cm （P〈O.01） while no significant tendency was found in the subgroup with its WC_〉85 cm （P=0.07）. Multiple stepwise regression analysis showed that the WC was an independent risk factor for C-IMT. In logistic regression model, the odd ratio of WC _〉80 cm, _〉80 cm and 〈85 cm and 〉85 cm for evaluating the risk of C-IMT elevation was 2.632, 2.501, and 1.878, respectively. Conclusion WC is significantly correlated with C-IMT in women from Shanghai, China, and WC_〉85 cm may be used in identifying the risk of subclinical carotid atherosclerosis.

Cut-off of body mass index and waist circumference to predict hypertension in Indian adults

AIM: To determine the cut-off values of body mass index(BMI) and waist circumference to predict hypertension in adults in north India.METHODS: A community based cross-sectional study was conducted in 801 subjects in Kanpur, aged 20 years and above, using multistage stratified random sampling technique. A pre-tested structured question-naire was used to elicit the required information from the study participants and the diagnostic criteria for hypertension were taken according to the Seventh Joint National Committee Report on Hypertension(JNC-7). Receiver operating characteristic(ROC) analysis was used to estimate the cut-off values of BMI and waist circumference to predict hypertension.RESULTS: The ROC analysis revealed that BMI is a good predictor of hypertension for both men(area under the ROC curve 0.714) and women(area under the ROC curve 0.821). The cut-off values of BMI for predicting hypertension were identified as ≥ 24.5 kg/m2 in men and ≥ 24.9 kg/m2 in women. Similarly, the ROC analysis for waist circumference showed that it is a good predictor of hypertension both for men(area under the ROC curve 0.784) and women(area under the ROC curve 0.815). The cut-offs for waist circumference for predicting hypertension were estimated as ≥ 83 cm for men and ≥ 78 cm for women. Adults with high BMI or high waist circumference had a higher prevalence of hypertension, respectively.CONCLUSION: Simple anthropometric measurements such as BMI and waist circumference can be used for screening people at increased risk of hypertension in order to refer them for more careful and early diagnostic evaluation. Policies and programs are required for primary and secondary prevention of hypertension.

Optimal Waist Circumference Cut-off values for Identifying Metabolic Risk Factors in Middle-aged and Elderly Subjects in Shandong Province of 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.

Changes in Waist Circumference and Abdominal Obesity among Chinese Adults over a Ten-year Period

Objective The aim of this study was to describe changes in waist circumference（WC） and prevalence of abdominal obesity over a period of 10 years among Chinese adults in different socio-economic status（SES）. Methods Data derived from the China Nutrition and Health Surveillance during 2002 and 2010-2012. We calculated the mean WC and the prevalence of abdominal obesity by gender, place of residence, SES indicators（education, income, and marital status）, and body mass index（BMI） categoriesand used pooled t-tests to assess the differences between the two time periods. Results 26.0% of men and 25.3% of women had abdominal obesity in 2010-2012. The age-adjusted mean WC increased by 2.7 cm among men and 2.1 cm among women; the age-adjusted prevalence of abdominal obesity increased by 7.7% among men and 5.3% among women. The rising trends were observed in all subgroups except for a negative growth in high-income women. People living in rural areas with low education and income and with a BMI of 18.5 to 23.9 kg/m^2 had a greater absolute and relative increase in WC. People living in rural areas with low income had a greater relative increase in abdominal obesity. Conclusion The mean WC and prevalence of abdominal obesity among Chinese adults have increased during the past 10 years. Gender differences were noted using various SES indicators.

Relationship between Waist Circumference and Elevation of Carotid Intima-media Thickness in Newly-diagnosed Diabetic Patients

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.

Performance of waist circumference relative to BMI in predicting risk of obesity and hypertension among affluent Indian adults

In view of the fact that Asians have higher abdominal fat at lower levels of body mass index (BMI), measures of abdominal adiposity such as waist circumference (WC) and waist to hip ratio (WHR) were investigated as predictors of hypertension. Data on BMI, WC, WHR and blood pressure (BP) were recorded through a cross-sectional study on 419 urban adults (210 men and 209 women;aged 30-60 years) in Pune, India. Abdominal obesity was higher among women than men (35.9% vs. 32.4%). However, age adjusted mean systolic BP (124.3 ± 15.1 mmHg vs. 114.7 ± 17.2 mmHg), diastolic BP (82.9 ± 10.5 mmHg vs. 76.4 ± 10.7 mmHg) and prevalence of hypertension (34.3% vs. 21.5%) was significantly higher (p < 0.01) among men than among women. Although both WC and WHR increased with increase in BMI, correlation coefficient of BMI with WC was significantly (p < 0.01) higher than that with WHR in both sexes, suggesting that WC could be better for assessing adiposity. In men, odds ratio [OR (95% CI) = 2.19 (1.08-4.45)] for hypertension was significant (p < 0.05) only for those in highest tertile of WC while it was significant (p < 0.01) even in the middle tertile in case of women [8.24 (2.67-25.43) for higher and 5.71 (1.82-17.89) for middle tertile]. Optimal cutoff for identifying obesity and hypertension showed significant (p < 0.01) area under curve (AUC) and sensitivity for WC than WHR in both sexes. The risk cutoffs were lower compared to those proposed by the World Health Organization especially for men, but were comparable with reported Asian studies. Thus, it was evident that WC performed better than BMI and WHR for assessing the risk of hypertension and may be used as a simple, convenient and inexpensive screening tool in epidemiological studies.

Waist Circumference of the Elderly over 65 Years Old in China Increased Gradually from 1993 to 2015: A Cohort Study

Objective This study aimed to analyze the temporal trends and characteristics associated with waist circumference(WC)among elderly Chinese people.Methods We used data from 3,096 adults≥65 years who participated in the China Health and Nutrition Survey(CHNS),an ongoing cohort study,between 1993 and 2015.We used longitudinal quantile regression models to explore the temporal trends and characteristics associated with WC.Results WC increased gradually among the elderly Chinese population during the survey.The WC curves shifted to the right with wider distributions and lower peaks in men and women.All WC percentile curves shifted upward with similar growth rates in the 25th,50th,and 75th percentiles.The WC means increased from 78 cm to 86 cm during the 22 years of our study.WC significantly increased with age and body mass index and decreased with physical activity(PA).These associations were stronger in the higher percentiles than in the lower percentiles.Conclusions WC is rising among Chinese adults≥65 years.Factors affecting WC in elderly people may have different effects on different percentiles of the WC distribution,and PA was the most important protective factor in the higher percentiles of the WC distribution.Thus,different interventional strategies are needed.

Earlier Menarche Can Be an Indicator of More Body Fat:Study of Sexual Development and Waist Circumference in Chinese Girls

Objective This paper aims to study the relationship between body fat and sexual development in Chinese girls with different waist circumference.Methods Six thousand one hundred and fifty six girls aged 6-19 were sampled.Their body weight,height,waist circumference,percentage of body fat and secondary sex characteristics were measured.All the subjects were divided into three groups：low class waist circumference,moderate class waist circumference and high class waist circumference.The menarche percentages were analyzed by using the status method.The menarche ages were analyzed by using the retrospective method.Estimates for mean age at entry into a pubertal stage and menarche were calculated by a probit analysis.Results The incidences of moderate class and high class waist circumstance were 20.94% and 25.27%,respectively.The sexual development of the former was earlier than that of the latter.The percentages of the menarche were detected as high classmoderate classlow class.The menarche ages were expressed as high classmoderate classlow class.Conclusion A close association is found between the waist circumference and sexual development,especially the menarche age.Girls with high class waist circumference are more vulnerable to earlier menarche and excess body fat.It is important to control the occurrence of central obesity through monitoring the change of waist circumference in puberty for girls＇ health.

Experimental Characterization of Operation of a Waist-Trunk System with Parallel Manipulators

An extensive research activity has been focused on the upper and lower limbs of humanoid robots. However, due to mechanical design difficulties and complex control of multi-body system, the torso of humanoid robot is somehow a neglected or simplified design part. In this paper, operation performance of a new waist-trunk system as torso for humanoid robots is presented through results of lab experimental tests. The proposed waist-trunk system is composed of two 3 DOFs （degrees of freedom） parallel manipulators, which are connected in a serial chain architecture. A prototype is built by using two prototypes of CaPaMan （Cassino Parallel Manipulator）, which are convenient stiff architectures with easy-operation characteristics. Experimental tests are carried out with the aims to imitate lateral-bending and transverse-rotation movements of human torso. Operation performances like displacements, accelerations, and actuation torque are measured for a performance evaluation and design characterization of the used manipulator solution imitating human torso. Experimental test results are illustrated and discussed to show the practical operation feasibility of the proposed architecture and the operation characteristics of the built prototype.

The effect of waist twisting on walking speed of an amphibious salamander like robot

Amphibious salamanders often swing their waist to coordinate quadruped walking in order to improve their crawling speed. A robot with a swing waist joint, like an amphibious salamander, is used to mimic this locomotion.A control method is designed to allow the robot to maintain the rotational speed of its legs continuous and avoid impact between its legs and the ground. An analytical expression is established between the amplitude of the waist joint and the step length. Further, an optimization amplitude is obtained corresponding to the maximum stride. The simulation results based on automatic dynamic analysis of mechanical systems（ADAMS） and physical experiments verify the rationality and validity of this expression.