Augmenting BMI and Waist-Height Ratio for Establishing More Efficient Obesity Percentiles among School-going Children

Research Questions:

1. Are all the existing methods for estimating the obesity and overweight in school going children in India equally efficient? 2. How to derive more efficient obesity percentiles to determine obesity and overweight status in school-going children aged 7-12 years old?

Objectives:

1. To investigate and analyze the prevalence rate of obesity and overweight children in India, using the established standards. 2. To compare the efficiency among the tools with the expected levels in the Indian population. 3. To establish and demonstrate the higher efficiency of the proposed percentile chart.

Study Design:

A cross-sectional study using a completely randomized design.

Settings:

Government, private-aided, unaided, and central schools in the Thrissur district of Kerala.

Participants:

A total of 1500 boys and 1500 girls aged 7-12 years old.

Results:

BMI percentiles, waist circumference percentiles, and waist to height ratio are the ruling methodologies in establishing the obese and overweight relations in school-going children. Each one suffers from the disadvantage of not considering either one or more of the obesity contributing factors in human growth dynamics, the major being waist circumference and weight. A new methodology for mitigating this defect through considering BMI and waist circumference simultaneously for establishing still efficient percentiles to arrive at obesity and overweight status is detailed here. Age-wise centiles for obesity and overweight status separately for boys and girls aged 7-12 years old were established. Comparative efficiency of this methodology over BMI had shown that this could mitigate the inability of BMI to consider waist circumference. Also, this had the advantage of considering body weight in obesity analysis, which is the major handicap in waist to height ratio. An analysis using a population of 1500 boys and 1500 girls has yielded 3.6% obese and 6.2% overweight samples, which is well within the accepted range for Indian school-going children.

Conclusion:

The percentiles for school-going children based on age and sex were derived by comparing all other accepted standards used for measurement of obesity and overweight status. Hence, augmenting BMI and waist to height ratio is considered to be the most reliable method for establishing obesity percentiles among school-going children.     

A comparison of distribution curves of body mass index from Brazil and the United States for assessing overweight and obesity in Brazilian adolescents.

OBJECTIVE: To assess the validity of recommendations for use of the 85th and 95th percentiles of body mass index (BMI) of the population in the United States of America as a screening tool to assess overweight/obesity in adolescents. METHODS: We investigated the relation between BMI and percent body fat in 1,540 adolescents (717 males and 823 females) aged 10 to 17.9 years old from a private high school in Niterói, a city in the state of Rio de Janeiro, Brazil. We used bioelectric impedance, with the appropriate equations for adolescents, to estimate percent body fat, which served as the gold standard (30% for girls and 25% for boys) to calculate the sensitivity and specificity of the 85th and 95th percentiles of the United States and Brazilian distribution curves of BMI. RESULTS: Sensitivity and specificity were high (above 80%) for the Niterói boys, except for the 85th percentile of the Brazilian curve (specificity = 61.8%) and for the 95th percentile of the United States curve (sensitivity = 55.4%). For the Niterói girls, the 85th- and 95th-percentile BMI cutoff points, from both the United States and Brazilian curves, showed low sensitivity, and that sensitivity decreased with age. Specificity was high for the girls, and much higher than it was for the boys. CONCLUSIONS: These data suggest that using BMI to screen for overweight/obesity in adolescents can generate a high percentage of false-positives for Niterói boys and an even higher percentage of false-negatives for Niterói girls. A more universal approach to using anthropometric measures to screen for overweight/obesity should be developed, preferably linked to stages of maturation.     

Waist-hip ratio and waist circumference associated with body mass index in a study with schoolchildren

The objectives of this study were to determine the percentile levels of the anthropometric indices body mass index (BMI), waist-hip ratio (WHR), and waist circumference (WC) and to verify possible correlations among theses indices in schoolchildren registered at the State Institute of Education, Florianópolis, Santa Catarina State, Brazil. A total of 419 children ages 7 to 9 years were investigated: 215 (51.3%) boys and 204 (48.7%) girls. BMI, WHR, and WC were higher for boys than for girls. However, the differences were only statistically significant for WHR and WC. Prevalence rates were 17.9% for overweight and 6.7% for obesity. The anthropometric indices with the highest correlation were BMI and WC (r = 0.87 and p < 0.01). For overweight, BMI and WC also presented the strongest correlation (r = 0.74). For obesity, WHR and WC showed the best correlation (r = 0.54).     

Prevalence of overweight and obesity in urban and semi-urban Jordanian children aged 3-6 years

Objectives   To show the prevalence of overweight and obesity among the Jordanian urban and semi-urban children; to compare their body mass index (BMI) with the international standards of BMI.
Methods   We measured 1695 healthy children (842 boys and 853 girls) between 3 and 6 years for height, weight and mid upper arm circumference. BMI was calculated and transformed into percentiles. Children were divided into boys and girls.
Results   The mean and SD values of BMI observed in our study were 16.69 ± 4.9 kg/m² for boys and 16.82 ± 4.77 kg/m² for girls aged 3–6 years. The prevalence of obesity and overweight among boys was 20.8% and 3.8% respectively and among girls was 19.1% and 7.2% respectively. In total, 48.0% of boys and 38.1% of girls were of healthy weight.
Conclusions   The mean BMI observed in our study's children aged 3–6 years was higher than the expected 50th percentile of the (World Health Organization/Centers for Disease Control and Prevention) reference values for a similar age range but, it was equivalent to the 75th percentile values. Obesity was more frequent than overweight among boys and girls aged 3–6 years.     

Obesity, overweight and thinness in schoolchildren of the city of Florianópolis, Southern Brazil

OBJECTIVE: To assess the prevalence of obesity, overweight (including obesity) and thinness in children of the city of Florianopolis (southern Brazil). DESIGN: Cross-sectional study. SUBJECTS: Representative sample of 7-10-y-old schoolchildren of the first four grades of elementary schools (1432 girls, 1504 boys). METHODS: Measurements of weight, height and triceps skinfold thickness (TSF) were taken following standard techniques. The body mass index (BMI) was computed as weight/height2. Nutritional status was defined using two references: (1) the Must et al reference for BMI and TSF to define thinness, overweight and obesity (5th, 85th and 95th percentiles, respectively); (2) the International Obesity Task Force (IOTF) BMI cutoffs to define overweight and obesity. RESULTS: Using BMI, according to the Must et al, and IOTF references, the prevalence of obesity was 10.6 and 5.5%, respectively; overweight (including obesity) affected 26.2 and 22.1% of children, respectively. According to the Must et al reference, the prevalence of thinness was 3.2%. Using TSF rather than BMI, according to the Must et al references, fewer children were classified as obese (8.0%) or overweight (20.2%) and more children were classified as thin (4.9%). CONCLUSION: This study supports the previously reported high frequencies of childhood overweight and obesity in developing countries. The data allow comparisons with other studies carried out in Brazil and other parts of the world.     

Weight status in childhood as a predictor of becoming overweight or hypertensive in early adulthood

OBJECTIVE: To assess the extent to which weight status in childhood or adolescence predicts becoming overweight or hypertensive by young adulthood. RESEARCH METHODS AND PROCEDURES: We conducted a prospective study of 314 children, who were 8 to 15 years old at baseline, and were followed up 8 to 12 years later. Weight, height, and blood pressure were measured by trained research staff. Incident overweight was defined as BMI>or=25 kg/m2 among participants who had not been overweight as children. RESULTS: More male subjects (48.3%) than female subjects (23.5%) became overweight or obese between their first childhood visit and the young adult follow-up (p<0.001). Being in the upper one half of the normal weight range (i.e., BMI between the 50th and 84th percentiles for age and gender in childhood) was a good predictor of becoming overweight as a young adult. Compared with children with a BMI<50th percentile, girls and boys between the 50th and 74th percentiles of BMI were approximately 5 times more likely [boys, odds ratio (OR)=5.3, p=0.002; girls, OR=4.8, p=0.07] and those with a BMI between the 75th and 84th percentiles were up to 20 times more likely (boys, OR=4.3, p=0.02; girls, OR=20.2, p=0.001) to become overweight. The incidence of high blood pressure was greater among the male subjects (12.3% vs. 1.9%). Compared with boys who had childhood BMI below the 75th percentile, boys between the 75th and 85th percentiles of BMI as children were four times more likely (OR=3.6) and those at above the 85th percentile were five times more likely (OR=5.1) to become hypertensive. DISCUSSION: High normal weight status in childhood predicted becoming overweight or obese as an adult. Also, among the boys, elevated BMI in childhood predicted risk of hypertension in young adulthood.     

北京与全国7～18岁儿童青少年腰围适宜界值对心血管危险因素筛查效度的对比分析

目的 比较北京与全国7～18岁儿童青少年腰围(WC)适宜界值对心血管危险因素的筛查效度和预测价值.方法 采用LMS曲线拟合法拟合北京市21 787名3～18岁儿童青少年WC百分位曲线,以性别、年龄别第75百分位数(P75)及第90百分位数(P90)作为北京市7～18岁儿童青少年WC适宜界值.在4927名7～18岁儿童青少年组成的验证人群中,比较北京和全国7～18岁儿童青少年WC适宜界值对高血压、脂代谢紊乱、糖耐量受损及非酒精性脂肪肝(NAFLD)等心血管危险因素诊断的特异度和灵敏度,通过回归分析比较该2个界值对心血管危险因素的预测价值.结果 北京市3～18岁儿童青少年WC适宜界值分别为:男童:P75为51.8～78.2 cm,P90为54.0～86.0 cm;女童:P75为50.8～72.1 cm,P90为53.3～77.3 cm.北京与全国界值筛查心血管危险因素的灵敏度分别为:高血压:男童分别为0.74和0.82,女童分别为0.68和0.73;低高密度脂蛋白胆固醇:男童分别为0.69和0.80,女童分别为0.64和0.71;NAFLD:男童分别为0.98和1.00,女童均为0.93.北京与全国界值筛查心血管危险因素的特异度分别为:高血压:男童分别为0.62和0.53,女童分别为0.68和0.63;低高密度脂蛋白胆固醇:男童分别为0.59和0.50,女童分别为0.66和0.61;NAFLD:男童分别为0.60和0.50,女童分别为0.56和0.51.北京和全国7～18岁儿童青少年WC的P90适宜界值预测心血管危险因素的OR(95%CI)值分别为:高血压分别为6.3(5.2～7.7)和6.0(4.9～7.4);空腹血糖受损均为1.3(1.1～1.5);脂代谢紊乱均为2.9(2.5～3.4);NAFLD分别为49.1(12.0～201.6)和69.8(9.7～504.2).结论 北京市7～18岁儿童青少年WC适宜界值可提高对心血管危险因素筛查的特异度;除对NAFLD预测价值低于全国界值外,北京界值对其他心血管危险因素的预测价值与全国界值没有明显差别.

Abstract：

Objective To compare the optimal references of waist circumference (WC) between Beijing and China in detecting cardiovascular risk factors in school-age children.Methods Percentile curves for WC were drawn by sex using LMS method based on 21 787 children and adolescents aged 7-18 from Beijing Child and Adolescent Metabolic Syndrome Study. The 75th and the 90th percentiles by age and by gender of WC percentile curves were chosen as the optimal WC reference for 3-18 years old children and adolescents in Beijing. The sensitivities(Se) and specificities(Sp) were compared between Beijing and China WC references based on the evaluation of cardiovascular risk factors including hypertension, dyslipidmia, impaired fasting glucose and non-alcoholic fatty liver disease (NAFLD) in the test population being composed of 4927 school children aged 7-18 years. The predictive values for those cardiovascular risk factors were compared between the two optimal thresholds through comparison of the odds ratio(OR) in regression analysis.Results The optimal reference for Beijing children and adolescents aged 3-18 years ranged from 51.8 to 78.2 cm for the 75th percentile in boys and 50.8 to 72.1 cm in girls, and the 90th percentile increased from 54.0 to 86.0 cm in boys and 53.3 to 77.3 cm in girls. The Ses of Beijing and China WC references in detecting hypertension were 0.74 and 0.82 in boys and 0.68 and 0.73 in girls; the Ses were 0.69 and 0.80 in detecting low-high density lipoprotein in boys and 0.64 and 0.71 in girls; and they were 0.98 and 1.00 in boys and both were 0.93 in girls for NAFLD. The Sps of Beijing and China WC references in screening hypertension were 0.62 and 0.53 in boys and 0.68 and 0.63 in girls, respectively. In predicting low-high density lipoprotein, the Sps were 0.59 and 0.50 in boys and 0.66 and 0.61 in girls, the Sps were 0.60 and 0.50 in boys and 0.56 and 0.51 in girls for predicting NAFLD. After adjustment for age and gender,ORs and their 95% credibility intervals(CI) of the 90th WC percentiles of Beijing and China school children were 6.3 (5.2-7.7) and 6.0 (4.9-7.4) in predicting hypertension. Both predictive ORs and their 95%CIs were 1.3 (1.1-1.5) in predicting impaired fasting glucose and the both were 2.9 (2.5-3.4) for dyslipdmia. In predicting NAFLD the ORs and their 95%CIs were 49.1(12.0-201.6) and 69.8 (9.7-504.2) for Beijing and China WC optimal references, separately.Conclusion Compared with Chinese WC reference, WC reference of Beijing had high Sps in screening cardiovascular risk factors in 7-18 years old children. The predictive values were not significant different between Beijing and China WC references for almost all cardiovascular risk factors except NAFLD. The WC reference in Beijing was more practical and handy for reference in Beijing and other north developed metropolises.     

上海市2000-2014年中小学生体质量指数变化趋势

了解2000-2014年上海市学龄儿童青少年体质量指数(BMI)的变化趋势,为儿童青少年超重、肥胖判别标准研制及预防干预提供参考.方法 选取2000,2005,2010,2014年4次全国学生体质与健康调研中7~18岁儿童青少年作为研究对象.应用最小均方(Least Mean Square,LMS)法探讨不同性别、年龄组儿童青少年BMI的变化趋势.结果 14年间学生BMI P85低年龄组差异比较小,随年龄增加差异逐渐增大,青春期后有减小的趋势,男生平均增加2.1百分点,女生平均增加1.3百分点.学生BMI增长主要集中在中等和高百分位数,尤其是P90后,差值逐渐增大.7~11,12~15岁男生在P5o后差值均逐渐增大,P95分别达2.0,3.2百分点,其中12岁男生从23.4 kg/m2增加到26.8 kg/m2,14岁女生从24.0 kg/m2增加到25.9 kg/m2.与WGOC标准相比,2014年男生BMI P85,P95均较高,而女生BMI P85 10岁之前高于WGOC标准,从11岁开始与WGOC标准基本相一致.2014年上海市7~18岁儿童青少年超重、肥胖检出率分别为15.4%,9.1%,较2000年总体均呈上升趋势,分别上升6.4,5.2百分点.结论 BMI分布高百分位的个体比低百分位个体的变化更大.在肥胖防治工作中,加强对群体BMI曲线的监测分析,对适时调整宏观调控战略意义重大.     

The high prevalence of overweight and obesity in Mexican children

OBJECTIVE: To establish the prevalence of overweight and obesity in Mexican children 10 to 17 years of age according to the percentiles from both the Centers of Disease Control and Prevention (CDC) and the International Obesity Task Force (IOTF). RESEARCH METHODS AND PROCEDURES: Heights and weights were measured in children from nationally representative, randomly chosen households in the Mexican National Health Survey 2000. The study population consisted of 7862 boys and 8947 girls, 10 to 17 years of age. Measurements used were the percentage of children in the corresponding BMI categories for overweight and obesity specified by the CDC and the IOTF BMI percentiles. RESULTS: The children were short, with mean Z scores for height by age varying from - 0.62 +/- 1.26 to -1.12 +/- 1.06 in boys and from -0.45 +/- 1.25 to -1.19 +/- 1.12 in girls. CDC-based overweight prevalences varied by age from 10.8% to 16.1% in boys and 14.3% to 19.1% in girls, with obesity prevalences from 9.2% to 14.7% in boys and 6.8% to 10.6% in girls; these prevalences did not relate to stunting. IOTF-based excess weight prevalences were similar, with higher overweight rates (boys, 15.4% to 18.8%; girls, 18.4% to 22.3%) but lower obesity rates (boys, 6.1% to 9%; girls, 5.9% to 8.2%). DISCUSSION: Mexican children have one-half the overweight/obesity prevalences of U.S. Mexican-American children; however, there are higher rates in Northern Mexico, which is closer to the U.S. These escalating rates of excess weight demand new prevention, as well as management, policies.     

Die Verbreitung von Übergewicht und Adipositas bei Kindern und Jugendlichen in Deutschland

Overweight and obesity are an increasing problem: worldwide, for Germany and for children and adolescents. Until now there have been no representative and age-specific assessments of the prevalence of obesity among children and adolescents in Germany. Thus, the standardised height and weight measurements gathered in the German Health Interview and Examination Survey for Children and Adolescents (KiGGS) have, for the first time, provided national, representative data about overweight and obesity in young people. The terms 'overweight' and 'obese' are defined based on percentiles of the body mass index (BMI) of the Kromeyer-Hauschild reference system. Of children and adolescents between the ages of 3 and 17, 15% exceed the 90th BMI percentile of the reference data and are thus overweight, 6.3% exceed the 97th BMI percentile and thus suffer from obesity by this definition. The proportion of overweight rises from 9% of 3-6-year-olds to 15% of 7-10-year-olds and 17% of 14-17-year-olds. The prevalence of obesity is 2.9%, 6.4% and 8.5% for the same age groups respectively. No clear differences between boys and girls or between East and West Germany are detected. Children are at a higher risk of being overweight or obese if they have a lower socioeconomic status, have a migration background, or have mothers who are also overweight.     

海口市7~14岁儿童腰围界值点及其肥胖相关性分析

目的分析海口市7~14岁儿童在超重和肥胖层面的腰围界值点,为儿童超重和肥胖防治策略制定提供科学依据。方法利用2016—2019年“海南省学生健康档案管理系统”,采用PPS抽样方法抽取海口220所中小学校,对学校整群抽样7~14岁儿童调取身高、体重和腰围数据进行整理分析。结果共计分析283054名7~14岁儿童,各年龄组儿童的平均腰围值和百分位点腰围值均低于全国平均腰围,腰围均随着年龄增长而持续增加。各年龄组儿童腰围男生均大于女生(P<0.0001),城市均高于农村(P<0.0001)。在超重层面,男童和女童界值点集中P 75~P 80(56.50~71.75 cm)、P 80~P 85(54.50~68.50 cm)。在肥胖层面,男童7~11岁和12~14岁的界值点分别是P 85(58.5~72.50 cm)、P 90(75.50~79.50 cm),女生7岁和8~14岁的界值点范围在分别是P 85(56.50 cm)和P 90(59.85~71.50 cm)。结论该地区在超重层面,男童和女童的界值点分别为56.50~71.75 cm和54.50~68.50 cm;肥胖层面,男童和女童的界值点分别是58.50~79.50 cm和56.50~71.50 cm。除了男生7岁和女生9岁超重界值点及女生青春期前8~10岁肥胖界值点外,其他各年龄组超重和肥胖界值点与全国的一致。     

Obesity and socioeconomic status in children of Tijuana

BACKGROUND: Although obesity has been associated with socioeconomic status among Hispanics living in the United States, little is known about whether a similar association exists among Hispanics living in Mexico, particularly among those living along the U.S.-Mexico border. OBJECTIVE: To determine the prevalence of obesity and its association with socioeconomic status in Mexican schoolchildren attending public and private schools in Tijuana, Baja California. METHODS: Anthropometric measurements and socioeconomic status were assessed in a cross-sectional study of 1172 school children, aged 6 to 13 years from 55 schools in Tijuana in 2001-2002. Underweight (body mass index [BMI] for age 5th percentile or lower), risk of overweight (BMI at 85th percentile or higher), and overweight (BMI greater than 95th percentile) were assessed using charts published by the Centers for Disease Control and Prevention. RESULTS: Abnormalities in weight were found in 46.3% of 587 boys and 43.7% of 585 girls in the study. Undernutrition was found in 3.7% of the boys and 3.8% of the girls. The general prevalence of overweight was 23.2% for boys and 21.7% for girls. Children living in low-income neighborhoods had the thickest biceps skinfolds (p<0.01), while children living in moderate-income neighborhoods and attending public schools had the thickest triceps skinfolds (p<0.001). Although boys living in high socioeconomic status neighborhoods were at decreased risk for being overweight, boys and girls attending private schools had a 75% increased risk (odds ratio, 1.75; confidence interval, 1.22-2.52) of being overweight than children attending public schools. CONCLUSIONS: Adiposity varies by type of school and neighborhood socioeconomic status. The biphasic curve in risk for being overweight associated with neighborhood socioeconomic status suggests that Mexican children living along the U.S. border may be experiencing a nutrition transition with respect to an increased risk of obesity and related chronic disease.     

Racial differences in the tracking of childhood BMI to adulthood

OBJECTIVE: The possibility that there are racial differences in the patterns of BMI (kilograms per meter squared) change throughout life has not been examined. For example, the high prevalence of obesity among black women could result from a higher prevalence of obesity among black girls or because normal-weight black girls experience larger BMI increases in adolescence or adulthood than do their white counterparts. Therefore, we examined the tracking of childhood BMI into adulthood in a biracial (36% black) sample. RESEARCH METHODS AND PROCEDURES: Five- to 14-year-old children (2392) were followed for (mean) 17 years. Childhood overweight was defined as BMI > or = 95th percentile, and adult obesity was defined as BMI > or = 30 kg/m(2). RESULTS: The tracking of childhood BMI differed between whites and blacks. Among overweight children, 65% of white girls vs. 84% of black girls became obese adults, and predictive values among boys were 71% (whites) vs. 82% (blacks). These racial differences reflected contrasting patterns in the rate of BMI change. Although the initial BMI of black children was not higher than that of white children, BMI increases with age were larger among black girls and overweight black boys than among their white counterparts. In contrast, relatively thin (BMI < 50th percentile) white boys were more likely to become overweight adults than were their black counterparts. DISCUSSION: These findings emphasize the black/white differences in BMI changes with age. Because of the adult health consequences of childhood-onset obesity, early prevention should be given additional emphasis.     

Factors associated with obesity among adolescents]

INTRODUCTION: Obesity during adolescence is considered a strong predictor of adult obesity. The present study assessed the overweight/obesity prevalence and associated factors in middle class adolescents of a school in the city of Niteroi, Rio de Janeiro, Brazil, and evaluated the correlation between body mass index with anthropometric measures of fatness. METHOD: The analysis covered 391 students aged from 15 to 17 years. Adolescents had their weight, height, skinfold thickness and upper arm circumference measured at school. A food frequency questionnaire (list of 79 items) and a questionnaire including food habits, parents anthropometric characteristics, physical activity and other factors associated with obesity were filled out by the adolescents at school. RESULTS: The proportion of overweight individuals among boys (Body Mass Index (BMI) greater than the 90th percentile of the Brazilian population) was 23.9%, whereas the prevalence among girls was 7.2%. The fact of being on a slimming diet was a relevant factor for the prediction of BMI and was 7 times more frequent among girls than among boys. Among boys, being on a diet, absence of breakfast, and family body appearance were positively associated with BMI. Among girls these variables were also significantly associated, whereas age at menarche was negatively associated with BMI. Hours of watching TV/video/video-game was associated with BMI only among boys. The correlation coefficient between BMI and measures of fatness varied from 0.7 to 0.9 for boys, and from 0.8 to 0.90 for girls. CONCLUSIONS: BMI appears to be a good indicator of obesity among adolescents and showed that girls demonstrated an exaggerated preoccupation with body image and stereotyped slim body patterns.     

Accuracy of different body mass index reference values to predict body fat in adolescents

This study evaluates the accuracy of cutoff points in the body mass index (BMI) for identifying adolescents with overweight, compared to the percentage of body fat, estimated by electric bioimpediance, in a probabilistic sample of 610 adolescents from 12 to 19 years of age (222 boys and 388 girls) enrolled in public schools in Niterói, Rio de Janeiro, Brazil. ROC was used to evaluate the sensitivity and specificity of BMI cutoffs from one Brazilian, two North American, and one international reference. The cutoff points in the study sample were lower than the other references, with 76% to 95% sensitivity and 75% to 95% specificity. The Brazilian cutoff points were also more sensitive (53% to 100%) as compared to the other references (40% to 86%). The international parameter showed better sensitivity for older adolescents, and the Northern American references for younger adolescents. BMI was a good proxy for adiposity, but cutoff points from other population references should be used with caution, since they can lead to classification errors in adolescents with overweight.     

Childhood Asthma and Extreme Values of Body Mass Index: The Harlem Children’s Zone Asthma Initiative

To examine the association between body mass index (BMI) percentile and asthma in children 2-11 years of age, we performed a cross-sectional analysis of 853 Black and Hispanic children from a community-based sample of 2- to 11-year olds with measured heights and weights screened for asthma by the Harlem Children's Zone Asthma Initiative. Current asthma was defined as parent/guardian-reported diagnosis of asthma and asthma-related symptoms or emergency care in the previous 12 months. Among girls, asthma prevalence increased approximately linearly with increasing body mass index (BMI) percentile, from a low of 12.0% among underweight girls (BMI 95th percentile). After adjusting for age, race/ethnicity, and household smoking, among girls, having asthma was associated with being at risk for overweight (odds ratio [OR], 2.6; 95% confidence interval [CI], 1.4-5.0) and being overweight (OR, 2.1; 95% CI, 1.2-3.8) compared to normal weight; among boys, having asthma was associated both with overweight (OR, 2.4; 95% CI, 1.4-4.3) and with underweight (OR, 2.9; 95% CI, 1.1-7.7). Large, prospective studies that include very young children are needed to further explore the observed association between underweight and asthma among boys. Early interventions that concomitantly address asthma and weight gain are needed among pre-school and school-aged children.     

徐州市0~7岁儿童身高、体重与体质指数研究

目的:对比世界通用的一些标准,建立徐州市0~7岁儿童年龄别身高(HFA)、年龄别体重(WFA)及年龄别体质指数(BM I)百分位标准及体质指数超重和肥胖界值点。方法:①采用分层整群随机抽样法,收集徐州市0~7岁儿童11 747例的性别、出生年月及2002~2004年身高和体重测量资料。②应用LMS方法建立徐州市0~7岁儿童HFA、WFA和BM I百分位曲线。结果:①运用LMS软件,分别获得0~7岁男女童HFA、WFA和BM I百分位曲线各9条,为P3、P5、P10、P25、P50、P75、P90、P95和P97。②徐州市男女童的身高随年龄不断增加,男童到6岁以后逐渐减缓,女童5岁后逐渐减缓。徐州市男女童的身高在7岁之前均大于WHO标准。③徐州市男女童的体重随年龄不断增加,到6岁以后均逐渐减缓。徐州市男女童体重7岁之前均高于WHO标准。④根据国际肥胖工作小组制定的7岁男女儿童肥胖和超重界值点,徐州市男女童7岁时通过该界值点的BM I百分位分别为:男童第72.6和第92.6,女童第82.1和第96.5。7岁男女童的超重流行率分别为27.4%和17.9%,肥胖流行率分别为7.4%和3.5%,在性别上存在差异。结论:应用LMS软件,获得了徐州市0~7岁儿童身高、体重和BM I百分位参考值。     

Mexican anthropometric percentiles for ages 10-18

OBJECTIVE: To elaborate Mexican growth charts based on international methodology. DESIGN: Data were obtained from the Mexican National Health Survey. The survey was stratified and probabilistic representative of all the country. SETTING: Nationwide open population living in urban and rural areas. SUBJECTS: Boys (8545) and girls (9983) from 10 to 18 years participating in the survey. METHODS: Age, weight and height were recorded. Empirical percentiles were calculated and smoothed. Smoothed curves were approximated using least-mean square estimation. RESULTS: Tables and figures for percentile values of weight, height and body mass index (BMI) for age, as well as percentile values of weight and BMI for height for both genders are presented. Regarding 50th BMI for age percentiles, Mexicans had higher levels than the Americans in the Centers for Disease Control and Prevention growth charts; Mexicans were lower but had similar weights than the Americans. Owing to the high BMI, the percentile corresponding to an overweight level (25 kg/m(2)) at 18 years was 74.5 in boys and 72.5 in girls, whereas obesity level (30 kg/m(2)) at 18 years was 97.3 and 97.4 in boys and girls, respectively. CONCLUSIONS: The present growth charts are snapshots of a Mexican population. Because of the high median BMI compared to US and World Health Organization standards, we must be cautious in establishing an upper normal cutoff for clinical normality, not merely selecting the 85th and 95th percentiles as equivalents of overweight and obesity, respectively. Therefore, we proposed percentiles 74.5 in boys and 72.5 in girls as the action points of overweight as they are the percentiles corresponding to BMI 25 kg/m(2) at 18 years. SPONSORSHIP: The survey was supported by the Mexican Minister of Health. Statistical analyses were sponsored by Dr Del-Rio-Navarro.     

Obesity in a cohort of black Jamaican children as estimated by BMI and other indices of adiposity

OBJECTIVE: To examine the relationships of body mass index (BMI) to obesity indices derived from anthropometry and to determine tracking of overweight between late childhood and early adolescence, in a cohort of children with mixed nutritional history. We also compared identification of overweight children using The International Obesity Task Force (IOTF) BMI cut-off points with skinfolds. DESIGN: Prospective study. SETTING: Kingston, Jamaica. SUBJECTS: A total of 306 children examined at 7-8 y and at 11-12 y. MEASUREMENTS: Triceps (TSF) and subscapular skinfolds (SSF), height and weight were measured. The sum of the skinfolds (sum SF), BMI, percentage body fat (%fat) and fat mass (FM) were calculated. Pubertal stage was assessed at 11-12 y. RESULTS: Overweight increased from 3.5 to 9.5% over the follow-up period. BMI was better correlated with the other indices of adiposity in girls and in the older age group. BMI tracking over follow up was high. In regression analysis BMI explained 52 and 61% of the variance in FM in boys and girls at 7-8 y. This increased to 69% in both sexes at 11-12 y. Using the IOTF cut-off points BMI had low sensitivity to identify children >85th percentile of the NHANES references for SSF. The sensitivity for those assessed by TSF and sum SF was higher, but between 14 and 30% of the children were misclassified. The specificity of BMI was high. CONCLUSIONS: Adiposity increased over follow-up. Although the cohort remained relatively lean BMI rank among the fattest children was maintained. Girls were fatter than boys, reflecting adult obesity patterns. Children identified as overweight by the IOTF BMI cut-off points are likely to have high body fatness. However the BMI cut-off points may not identify many children with high body fatness.     

北京市海淀区1985-2010年中小学生肥胖变化趋势分析

目的 了解北京市海淀区1985 -2010年中小学生超重、肥胖及体质量指数(BMI)变化趋势,为儿童青少年肥胖干预政策的制定提供科学依据.方法 使用1985 -2010年中国学生体质与健康调研北京市海淀区资料,根据身高和体重计算BMI,应用中国肥胖工作组(WGOC)“中国学龄儿童青少年超重、肥胖筛查BMI分类标准”判定超重和肥胖,比较7 ～18岁学生各年度超重与肥胖检出率,分析各百分位数BMI( P25,P50,P75,P90,P95)变化趋势.结果 1985 -2010年7～18岁男生肥胖率分别为1.0％,4.0％,6.5％,15.2％,女生分别为0.5％,2.1％,2.8％,5.2％.各年龄组男、女生超重、肥胖率以及各百分位数BMI值均随年度不断上升(P值均＜0.01).1985 -2010年各百分位数BMI增长表现为男生增速高于女生,较高百分位BMI值增速高于较低百分位BMI值,各年龄组高百分位BMI值全面大幅上升.2000-2010年以来10～15岁男、女生BMI增速明显.结论 北京市海淀区1985 -2010年学生超重、肥胖检出率以及BMI水平持续增长,10～15岁学生是下一步肥胖防控的重点对象.