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.     

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

The body mass index of Chinese population is lower than that of the Westerncountries, however, the trends of mean body mass index and prevalence of overweight inadults have increased significantly in recent 15 years[1]. Overweight and obesity areclosely r…     

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.     

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/m2 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.     

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

ObjectiveTo evaluate whether waist circumference (WC) ≥85 cm is related to asymptomatic preclinical atherosclerosis in women from Shanghai, China.MethodsA 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.ResultsThe C-IMT was significantly higher in overweight or obese women with their BMI ≥25.0 kg/m² (P<0.01) and in those with their WC ≥85 cm than in those with their WC <85 cm (P<0.01). 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<0.01) 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 1.632, 1.501, and 1.878, respectively.ConclusionWC 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.     

Nutrition in Chinese-Korean Children and Adolescents

ObjectiveTo study the nutrition habits among Chinese-Korean children and adolescents in Yanbian Autonomous Prefecture, Jilin, China. MethodsData were obtained from the Chinese National Survey on Students’ Constitution and Health in 1995, 2000, 2005, and 2010 for Chinese-Korean children and adolescents aged 7-18 years.The number of the subjects included was 4789, 4704, 5875, and 5315, respectively. ResultsThe rate of the occurrence of stunting showed a declining trend from 1995 to 2010 (for boys:urban, 6.3%; rural, 12.7% in 1995 and 3.5% for both in 2010. For girls: urban, 7.8%; rural, 13.4% in 1995 and 4.2% and 5.5%, respectively, in 2010). Although the ratio of wasting did not show significant differences between the urban and rural children and adolescents in 1995, 2000, 2005, and 2010 respectively, the ratio of occurrence of overweight or obesity increased (for boys: urban, 7.3% and 1.3%in 1995, 17.6% and 12.9% in 2010; rural, 7.0% and 1.3% in 1995, 14.6% and 12.8% in 2010, respectively. For girls: urban, 8.1% and 1.0% in 1995, 17.3% and 8.6% in 2010; rural 5.7% and 0.7% in 1995, 16.4%and 7.4% in 2010, respectively). ConclusionThe ratio of malnutrition in children and adolescents in Chinese-Korean areas declined from 1995 to 2010, and the distinction in malnutrition between the urban and rural areas was negligible in 2010. Further, the ratio of overweight and obesity increased over this period.     

Secular Changes on the Distribution of Body Mass Index among Chinese Children and Adolescents, 1985-2010

ObjectiveTo analyze the change in Body Mass Index (BMI) distribution among Chinese children and adolescents for the development of more effective intervention for childhood obesity.MethodsData on the national students' constitution and health survey between 1985 and 2010 was used for this study. Subjects were students aged 7-18 randomly selected from 30 provinces in China. BMI for-age curves were developed by LMS method, and the trend of BMI distribution was determined by comparing the upper BMI percentiles and analyzing the skew shift of distribution between 1985 and 2010.ResultsAn overall positive swift trend of BMI between 1985 and 2010 was observed among the Chinese school-age children and adolescents. The average median of the BMI increased from 16.8 and 17.0 kg/m² to 18.2 and 17.9 kg/m² in 25 years, with increments 0.56 and 0.36 kg/m² per decade for males and females, respectively. The more obvious increments were found at the high BMI. The total increments of BMI in this period were 4.03 and 2.20 kg/m² at the 85th, 6.14 and 3.57 kg/m² at the 95th, and 6.99 and 4.27 kg/m² at the 97th percentiles, for males and females, respectively.ConclusionObvious increments were observed at high BMI of the Chinese children and adolescents. More effective interventions should be taken for control and prevention of obesity and its health consequence for these subgroups. It is necessary to establish a risk-complex system consisting of the identification of BMI scope, the screen of the disease risk factors and the assessment of excessive adiposity.     

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(P0.05). 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(P0.05). Both spearman and partial correlation analysis showed that C-IMT was positively correlated with waist circumference(P0.01). 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 P0.05), 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, P0.05). 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.     

Report on Childhood Obesity in China （4） Prevalence and Trends of Overweight and Obesity in Chinese Urban School-age Children and Adolescents, 1985-2000

Objective To describe the nationwide prevalence of childhood overweight/obesity, and their group variations and trends over the past 20 years in the Chinese urban population. Methods Data sets of boys and girls at the age of 7-18 years collected from the series of Chinese national surveillance on students' constitution and health (CNSSCH) between 1985 and 2000 were divided into five socioeconomic and demographic groups, while BMI classification reference proposed by Working Group on Obesity in China (WGOC) was used as screening reference to calculate the prevalence and trends of overweight/obesity in these groups. Results In 2000, the prevalence of obesity and overweight in boys aged 7-18 years was 11.3% and 6.5% in Beijing, 13.2% and 4.9% in Shanghai, 9.9% and 4.5% in coastal big cities, and 5.8% and 2.0% in coastal medium/small-sized cities, respectively, while the prevalence of of obesity and overweight in girls of the same age group was 8.2% and 3.7% in Beijing, 7.3% and 2.6% in Shanghai, 5.9% and 2.8% in coastal big cities, and 4.8% and 1.7% in coastal medium/small-sized cities, respectively. The prevalence of obesity was low in most of the inland cities at an early stage of epidemic overweight. The epidemic manifested a gradient distribution in groups, which was closely related to socioeconomic status (SES) of the study population. However, a dramatic and steady increasing trend was witnessed among all sex-age subgroups in the five urban groups, and such a trend was stronger in boys than in girls, and much stronger in children than in adolescents. Conclusion Although China is at an early stage of epidemic obesity by and large, the prevalence of obesity in her urban population, particularly in coastal big cities has reached the average level of developed countries. The increasing trend has been rapid since early 1990s, and the increments in obesity and overweight are exceptionally high. The prospect of epidemic obesity in China is in no way optimistic. Therefore, preventive program should be focused on the improvement of the balance between caloric intake and energy expenditure, and interventions aimed at changing children's life styles.     

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

For prevention of obesity in Chinese population, it is necessary to define the optimal range of healthy weight and the appropriate cut-off points of BMI and waist circumference for Chinese adults. The Working Group on Obesity in China under the support of International Life Sciences Institute Focal point in China organized a meta-analysis on the relation between BMI, waist circumference and risk factors of related chronic diseases (e. g.,high diabetes, diabetes mellitus, and lipoprotein disorders). Methods 13 population studies in all met the criteria for enrollment, with data of 239 972 adults (20-70 year) surveyed in the 1990s. Data on waist circumference was available for 111411 persons and data on serum lipids and glucose were available for more than 80 000. The study populations located in 21provinces, municipalities and autonomous regions in mainland China as well as in Taiwan. Each enrolled study provided data according to a common protocol and uniform format. The Center for data management in Department of Epidemiology, Fu Wai Hospital was responsible for statistical analysis. Results and conclusion The prevalence of hypertension, diabetes, dyslipidemia and clustering of risk factors all increased with increasing levels of BMI or waist circumference. BMI at 24 with best sensitivity and specificity for identification of the risk factors, was recommended as the cut-off point for overweight, BMI at 28 which may identify the risk factors with specificity around 90 % was recommended as the cut-off point for obesity. Waist circumference beyond 85 cm for men and 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 normal range (＜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 waist circumference controlled under 85 cm for men and under 80 cm for women, could prevent 47%-58% clustering of risk factors. According to these, a classification of overweight and obesity for Chinese adults is recommended.     

体重指数和腰围用于肥胖的营养评定

本文介绍了体重指数和腰围在肥胖营养评定中的价值和局限性,并强调将二者结合用于评定肥胖的重要性.     

儿童青少年单纯性肥胖相关危险因素的调查研究

目的了解目前引起宁夏银川地区儿童青少年单纯性肥胖的相关危险因素。方法采用问卷调查的方法,对300例儿童青少年进行包括家庭情况、生活方式、饮食习惯及膳食营养的调查,并对所得资料进行Logis-tic回归分析。结果Logistic回归分析显示父亲体重指数越大、母亲文化水平越高,儿童青少年发生肥胖的危险越大;同时饭量较同龄学生大、进食速度快、较少参加课外活动、每日热能、脂肪摄入量高等因素是儿童青少年肥胖的相关危险因素,差异有统计学意义(P<0.05)。结论改变不良生活方式、饮食习惯、控制热能及脂肪摄入,是预防和控制肥胖发生发展的关键。     

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

ObjectiveThis study aimed to analyze the temporal trends and characteristics associated with waist circumference (WC) among elderly Chinese people.MethodsWe 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.ResultsWC 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.ConclusionsWC 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.     

拉萨藏族儿童青少年皮下脂肪的分布特点

目的通过皮褶厚度及其指数了解拉萨藏族儿童青少年体脂肪分布现状。方法在知情同意的情况下,从拉萨中小学随机抽取1293例（男622例,女671例）藏族儿童青少年为研究对象,按照《人体测量方法》相关规定测量各项指标,所有调查数据输入SPSS统计软件包,进行统计学处理。结果拉萨藏族女性儿童青少年躯干部和四肢部皮下脂肪均匀分布,随着年龄增长,皮下脂肪逐渐增厚;男性进入青春期后,躯干部皮下脂肪逐渐增厚,四肢部皮下脂肪逐渐变薄。用3种皮褶厚度指数表示脂肪分布时,不论男性女性,8～12岁时呈外周型分布,约在13岁开始,各皮褶厚度指数开始在向心型分布的方向上增加,呈全身型分布;约在16岁开始,男性向心型分布趋势明显大于女性。结论通过皮褶厚度可以相对简便地推测出儿童青少年的脂肪分布特点及发展趋势。     

中青年体质指数、腰围及腰臀比与脑卒中发生的相关性研究

目的探讨中青年人肥胖的不同指标,如体质指数(BMI)、腰围(WC)及腰臀比(WHR)与脑卒中发生的关系。方法采用以医院为基础的病例对照研究。病例组由280例脑卒中(缺血性脑卒中和出血性脑卒中)患者组成,对照组为患其他与脑卒中无关的疾病同期入住和病例组相同医院的280例患者。采用标准调查表对研究对象进行调查,收集研究对象的人口学特征、生活方式、个体疾病史、脑卒中家族遗传史以及实验室检查等资料,同时对身高、体质量、WC、臀围进行测量,并计算BMI及WHR。采用多元Logistic回归分析对研究对象的BMI、WC及WHR与脑卒中的比值比(OR)及其95%可信区间(CI)进行估计。结果 280例脑卒中患者中出血性76例,缺血性204例。与正常BMI者相比较,调整年龄、性别后的分析结果显示,超重或肥胖的病例发生缺血性脑卒中的危险性明显高于对照组〔超重者:OR=2.03,95%CI(1.26,2.91),P<0.05;肥胖者:OR=1.88,95%CI(1.32,2.39),P<0.05〕。与BMI最低四分位数相比,BMI最高四分位数的病例发生缺血性脑卒中的危险性增加了18%〔OR=1.18,95%CI(1.06,3.54),P<0.01〕。WC最高四分位数的病例发生出血性和缺血性脑卒中的危险性分别是WC最低四分位数的1.80和1.96倍〔OR=1.80,95%CI(1.03,3.16)和OR=1.96,95%CI(1.37,3.78),P<0.01〕。与WHR最低四分位数比较,WHR最高四分位数的病例发生出血性及缺血性脑卒中的危险性分别增加了98%和126%〔OR=1.98,95%CI(1.41,3.59),P<0.01和OR=2.26,95%CI(1.34,2.79),P<0.01〕。结论 BMI增高是发生脑卒中的一个重要危险因素,WC增加可使发生缺血性脑卒中的危险性显著升高,而WHR与发生出血性及缺血性脑卒中的危险性呈正相关。维持正常体质量可能是脑卒中发病的保护因素。     

宁夏地区儿童青少年体重指数与血压关系的研究

目的研究宁夏地区儿童青少年体重指数与血压的关系。方法收集2005年宁夏地区13039名7~18岁回汉中小学生的体质检查资料,以全国学龄儿童第95百分位数值判定高血压,统计分析儿童青少年体重指数与血压的关系。结果控制了年龄、性别、民族后,体重指数与收缩压、舒张压显著相关,偏相关系数分别为0.122和0.125(P<0.001);宁夏地区儿童青少年高血压患病率为4.83%,其中超重肥胖学生与体重正常学生高血压患病率分别为12.71%和4.16%,两者相比OR值为3.353。结论儿童青少年血压随体重指数的增加而升高,超重及肥胖者患高血压的危险是体重正常者的3倍,预防高血压应从儿童抓起。     

学龄儿童肥厚型心肌病彩色多普勒超声心动图特征和规律性研究

目的 探寻学龄儿童肥厚性心肌病（HCM）彩色多普勒超声心动图（CDE）特征和规律性。方法 连续37例学龄儿童HCM患者,同期30例性别年龄体重相近的正常学龄儿童志愿者作为对照组,应用CDE对比观察,寻找HCM患儿CDE特征和规律性。结果 二维超声心动图在胸骨旁左心室长轴切面显示HCM组97.3%患儿室间隔均明显增厚并凸向左心室流出道,67.6%左心室流出道不同程度狭窄,所有患儿左心室内径均有不同程度缩小,32.4%合并左心室后壁增厚。M型超声心动图测量HCM组与对照组数据室间隔厚度为11.8±0.8mm和5.4±0.6mm、左心室内径为34.4±1.4mm和39.8±1.9mm和左心室容积指数为33.3±2.3ml/m²和53.3±2.9ml/m²、左心室射血分数为82.5%±1.7%和65.5%±1.7%,差异有统计学意义（P=0.000）。67.6%显示二尖瓣前叶运动曲线CD段向前运动即SAM征阳性。连续波多普勒估测HCM组跨左心室流出道压力阶差,32.4% < 30mmHg、54.1% 30~49mmHg、13.5% 50~75mmHg。HCM组彩色多普勒流显像于收缩期67.6%显示过左心室流出道五彩镶嵌射流束血流信号,45.9%显示过二尖瓣五彩镶嵌返流束血流信号。结论 学龄儿童HCM的CDE特征和规律性明显,CDE对学龄儿童HCM具有特异性诊断价值,但需要与主动脉瓣狭窄鉴别诊断。     

铁缺乏状态学龄儿童视听整合持续操作测试的初步研究

目的探讨铁缺乏状态学龄儿童是否存在反应控制能力缺陷和注意力缺陷。方法选择2005年5月-2006年6月在我院儿童保健门诊就诊的6．12岁铁缺乏状态儿童和健康儿童各42例，分别设为铁缺乏组和对照组；应用视听整合持续操作测试软件，进行反应控制能力和注意力测试。对铁缺乏状态学龄儿童补充铁剂治疗8wk后再进行反应控制能力和注意力测试。结果铁缺乏状态学龄儿童各项反应控制能力商数和注意力商数均低于对照组，差异有显著性意义p〈0．05。铁缺乏组经过8wk铁剂治疗后血清铁蛋白及各项反应控制能力商数和注意力商数均高于治疗前，差异有显著性意义p〈0．05。结论铁缺乏状态学龄儿童反应控制能力和注意力均下降，经铁剂治疗后有效。