Triceps and subscapular skinfold thicknesses percentiles and cut-offs for overweight and obesity in a population-based sample of schoolchildren in Bogota, Colombia

OBJECTIVES: The aims of this study were to establish a Colombian smoothed centile charts and LMS tables for tríceps, subscapular and sum tríceps+subscapular skinfolds; appropriate cut-offs were selected using receiver operating characteristic analysis based in a populationbased sample of schoolchildren in Bogota, Colombia and to compare them with international studies. METHODS: A total of 9 618 children and adolescents attending public schools in Bogota, Colombia (55.7% girls; age range of 9–17.9 years). Height, weight, body mass index (BMI), waist circumference, triceps and subscapular skinfold measurements were obtained using standardized methods. We have calculated tríceps+subscapular skinfold (T+SS) sum. Smoothed percentile curves for triceps and subscapular skinfold thickness were derived by the LMS method. Receiver operating characteristics curve (ROC) analyses were used to evaluate the optimal cut-off point of tríceps, subscapular and sum tríceps+subscapular skinfolds for overweight and obesity based on the International Obesity Task Force (IOTF) definitions. Data were compared with international studies. RESULTS: Subscapular, triceps skinfolds and T+SS were significantly higher in girls than in boys (P <0.001). The median values for triceps, subscapular as well as T+SS skinfold thickness increased in a sex-specific pattern with age. The ROC analysis showed that subscapular, triceps skinfolds and T+SS have a high discrimination power in the identification of overweight and obesity in the sample population in this study. Based on the raw non-adjusted data, we found that Colombian boys and girls had high triceps and subscapular skinfolds values than their counterparts from Spain, UK, German and US. CONCLUSIONS: Our results provide sex- and age-specific normative reference standards for the triceps and subscapular skinfold thickness values in a large, population-based sample of 3 schoolchildren and adolescents from an Latin-American population. By providing LMS tables for Latin-American people based on Colombian reference data, we hope to provide quantitative tools for the study of obesity and its complications.

The nature of malnutrition in children with end-stage liver disease awaiting orthotopic liver transplantation

To evaluate malnutrition in chronic liver disease, and its relationship to nutrient deficiencies and hepatic dysfunction. 27 children with end-stage liver disease were studied. Mean protein-energy intakes were 70% of recommended daily intakes. The patients were underweight and stunted with reduced mean triceps and subscapular skinfold thicknesses and midupper arm circumference. Mean total body potassium was only 63 ± 18% of that expected for age and sex. Deficiency of essential fatty acids (32%), and low concentrations of fat-soluble vitamins (A, 92%; E, 32%), iron (32%), zinc (42%), and selenium (13%) were common. Serum ammonia concentrations were raised in all patients, and increased methionine, tyrosine, and glutamic acid, and reduced glutamine concentrations were noted. There was no correlation between the degree of malnutrition and the degree of liver synthetic function, the degree of cholestasis, or the degree of liver injury. We suggest that potentially correctable factors in addition to liver failure (eg, inadequate absorbed intake) were important determinants of malnutrition in these patients.

Sarcopenia em pacientes idosos com doença renal crônica em hemodiálise

Os pacientes idosos em hemodiálise (HD) são altamente suscetíveis ao desenvolvimento de sarcopenia, devido ao processo natural de envelhecimento e ao catabolismo induzido pelo procedimento de HD. O objetivo deste estudo foi primeiro, avaliar a prevalência de sarcopenia, dinapenia e atrofia muscular em um grupo de pacientes idosos em HD; o segundo, avaliar se os critérios aplicados para o diagnóstico de sarcopenia, propostos por sociedades internacionais, são capazes de distinguir os pacientes com pior condição clínica, estado nutricional e qualidade de vida. Este estudo multicêntrico e transversal incluiu 94 pacientes idosos em HD (> 60 anos) de cinco centros de diálise. Todos os participantes foram submetidos à avaliação antropométrica, de composição corporal, força de preensão manual (FPM), laboratorial e avaliação da condição nutricional através da avaliação subjetiva global de 7 pontos (AGS-7p). Adicionalmente, os participantes responderam um questionário de qualidade de vida. Para o diagnóstico de sarcopenia, foram adotados os critérios propostos por sociedades internacionais, que englobam os parâmetros indicativos de baixa massa muscular e baixa função muscular. Para a massa muscular adotou-se o índice de massa magra (IMM) < percentil 20 para o gênero e faixa etária de uma população de referência, avaliado a partir da massa magra obtida pelo somatório de dobras cutâneas. Para o critério de baixa função muscular, adotou-se a FPM < percentil 10 para o gênero, faixa etária e o braço utilizado de uma população de referência. Os pacientes foram classificados como Sarcopênicos (baixo IMM associado à baixa FPM); Dinapênicos (baixa FPM) e Atrofia muscular (baixo IMM). A sarcopenia estava presente em 13.8% dos pacientes, enquanto a dinapenia foi observada em 37.2% e a atrofia muscular em 35.1%. A sarcopenia foi capaz de distinguir os pacientes que possuíam maior comprometimento do estado nutricional e da composição corporal. O critério de função muscular (isoladamente ou em combinação com a massa muscular) também identificou os pacientes com pior qualidade de vida. Em conclusão, a prevalência de sarcopenia foi observada em 13,8% do grupo. Entretanto, ao usar apenas critérios que indicam redução da força ou massa muscular, esta prevalência aumentou para 30%. A condição de sarcopenia distinguiu pacientes com pior estado nutricional e qualidade de vida.

Dietary glycemic index and glycemic load in relation to changes in body composition measures during adolescence:Northern Ireland Young Hearts Study

Background: Epidemiologic evidence on the influence of dietary glycemic index (GI) and glycemic load (GL) on the development of obesity is limited.

Objective: This prospective study examined the associations between dietary GI and GL and changes in body composition measures during adolescence.

Design: In a representative sample of Northern Irish adolescents aged 12 years at baseline and 15 years at follow-up (n=426), dietary intake was assessed by a diet history interview. Body composition measures included body mass index (BMI; kg m(-2)), BMI z-score, sum of four skinfold thicknesses, percentage body fat, fat mass index (FMI; kg m(-2)) and fat-free mass index (kg m(-2)).

Results: After adjustment for potential confounding factors, baseline GI was associated with increased change in FMI. Mean (95% confidence interval) values of changes in FMI according to tertiles of baseline GI were 0.41 (0.25, 0.57), 0.42 (0.26, 0.58) and 0.67 (0.51, 0.83) kg m(-2), respectively (P for trend=0.03). There was no significant association of baseline GI with changes in other body composition measures (P for trend0.054). Conversely, baseline GL showed no association with changes in any of the measures (P for trend0.41). Furthermore, changes in GI or GL were not associated with changes in any of the measures (P for trend0.16).

Conclusion: Dietary GI at age 12 years was independently associated with increased change in FMI between ages 12 and 15 years in a representative sample from Northern Ireland, whereas dietary GL showed no association with changes in any of the body composition measures examined.

Percentiles de circunferencia de cintura en escolares de Bogotá, Colombia Estudio FUPRECOL

Objetivo: Determinar la distribución por percentiles de la circunferencia de cintura en una población escolar de Bogotá, Colombia, pertenecientes al estudio FUPRECOL. Métodos: Estudio transversal, realizado en 3.005 niños y 2.916 adolescentes de entre 9 y 17,9 años de edad, de Bogotá, Colombia. Se tomaron medidas de peso, talla, circunferencia de cintura, circunferencia de cadera y estado de maduración sexual por auto-reporte. Se calcularon los percentiles (P3, P10, P25, P50, P75, P90 y P97) y curvas centiles según sexo y edad. Se realizó una comparación entre los valores de la circunferencia de cintura observados con estándares internacionales. Resultados: De la población general (n=5.921), el 57,0% eran chicas (promedio de edad 12,7±2,3 años). En la mayoría de los grupos etáreos la circunferencia de cintura de las chicas fue inferior a la de los chicos. El aumento entre el P50-P97 de la circunferencia de cintura , por edad, fue mínimo de 15,7 cm en chicos de 9-9.9 años y de 16,0 cm en las chicas de 11-11.9 años. Al comparar los resultados de este estudio, por grupos de edad y sexo, con trabajos internacionales de niños y adolescentes, el P50 fue inferior al reportado en Perú e Inglaterra a excepción de los trabajos de la India, Venezuela (Mérida), Estados Unidos y España. Conclusiones: Se presentan percentiles de la circunferencia de cintura según edad y sexo que podrán ser usados de referencia en la evaluación del estado nutricional y en la predicción del riesgo cardiovascular desde edades tempranas.

Desempenho de diferentes equações antropométricas na predição de gordura corporal excessiva em crianças e adolescentes

OBJETIVO: O objetivo do presente estudo foi analisar a eficiência de diferentes equações antropométricas para a identificação de excesso de gordura corporal entre crianças e adolescentes. MÉTODOS: A amostra foi composta por 1.498 indivíduos (678 meninos e 820 meninas), com idade entre 7 e 17 anos (M=13,7, DP=2,0), da cidade de Presidente Prudente (SP). A massa corporal e a estatura foram mensuradas para o cálculo do Índice de Massa Corporal. Também foi realizada a mensuração da circunferência de cintura e das dobras cutâneas subescapular, tricipital, abdominal e da panturrilha. O percentual de gordura corporal foi calculado por meio de quatro equações: Slaughter et al., Slaughter II et al., Dezenberg et al., e Deurenberg et al.. Para indicar a eficiência das diferentes equações antropométricas na indicação da obesidade, foi utilizada a análise da curva Receiver Operating Characteristic Curve. RESULTADOS: No grupo masculino, foram observados valores de sensibilidade elevados (82,4% a 100,0%) e valores oscilando de baixo a alto, para a especificidade (20,9% a 94,9%). Para o sexo feminino, os valores de sensibilidade variaram entre moderado e alto (72,2% a 99,4%); e os de especificidade apresentaram, também, grande oscilação entre baixo e alto (21,6% a 98,2%). CONCLSÃO: A equação proposta por Deurenberg et al., apresentou o melhor desempenho no diagnóstico tanto da presença como da ausência de obesidade na amostra investigada.

Handgrip strength predicts pressure ulcers in patients with hip fractures

Objective: Pressure ulcer (PU) is a frequent complication of hip fracture. Studies were carried out to identify the risk factors of PU development after hip fractures. The objective of the study was to determine the role of anthropometric measurements and handgrip strength as predictors of PUs in patients with hip fractures during their hospital stay and 30 d after discharge, which has not yet been established.Methods: Ninety-two consecutive patients with hip fractures who were older than 65 y old and admitted to an orthopedic unit were prospectively evaluated. Within the first 72 h of admission, each patient's characteristics were recorded, anthropometric measurements were taken (circumferences of the arm, waist, thigh, calf, triceps, and biceps and subscapular and suprailiac skinfolds), handgrip strength was measured, and blood samples were collected. PU evaluations were performed during the hospital stay and 30 d after hospital discharge.Results: Three patients were excluded because of PUs before hospitalization. Eighty-nine patients (average age 80.6 +/- 7.5 y) were studied; 70.8% were women, and 49.4% developed PUs during their hospital stay. In a univariate analysis, length of hospital stay (P = 0.001) and handgrip strength (P = 0.02), but not body circumferences and skinfolds, were associated with PUs during a hospital stay. Only handgrip strength (P = 0.007) was associated with PUs 30 d after hospital discharge. In a multivariate analysis, only handgrip strength was found to predict PU development at these points.Conclusion: Handgrip strength was found to predict PU development in patients with hip fractures during their hospital stay and 30 d after discharge. (C) 2012 Elsevier B.V. All rights reserved.

O uso das pregas cutâneas e da circunferência muscular do braço no diagnóstico de desnutrição energético-protéica em pacientes adultos: estudo crítico.

The use of anthropometric measurements of triceps (TSF) and subscapular skinfolds (SSF) and mid-upper arm muscle circumference (MAMC) was examined as far as the diagnosis of energy-protein malnutrition (EPM) is concerned. The study was undertaken in five groups of patients (n = 231): arterial hypertension (AH, n = 63), chronic obstructive pulmonary disease (COPD, n = 17), hemodialyzed chronic renal failure (CRF, n = 19), critically ill patients with an acute event (CA, n = 42) and critically ill patients with chronic diseases (CCD, n = 90). The results were compared to those obtained in a group of healthy individuals (control group, n = 102). The control group and the group of patients were allocated in subgroups according to sex and age (less than 50 and more than 50 years). It was expected that significant differences would be found for the anthropometric values between the control subgroups and the COPD, the CRF and the CCD subgroups of patients. For the skinfold thicknesses (TSF and SSF), significant differences were found between CRF, CCD subgroups and the control subgroups under fifty years of age; however, the differences were not significant when the subgroups over fifty were analyzed. Concerning the MAMC, significant differences were found: 1 degree) between the CRF subgroups (males and females) and the control subgroups under fifty years of age; 2 degrees) between the CCD male subgroups (younger and older subgroups) and the respective control subgroups and 3 degrees) between the COPD and the control subgroups.(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of Cardiorespiratory Fitness on PPARG mRNA Expression Using Monozygotic Twin Case Control

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Prediction of cardiovascular disease risk factors in Mexican-American children from parental risk factors, and social and demographic characteristics in the HHANES

Objectives. Cardiovascular disease (CVD) including CVD secondary to diabetes type II, a significant health problem among Mexican American populations, originates in early childhood. This study seeks to determine risk factors available to the health practitioner that can identify the child at potential risk of developing CVD, thereby enabling early intervention. ^ Design. This is a secondary analysis of cross-sectional data of matched Mexican American parents and children selected from the HHANES, 1982–1984. ^ Methods. Parents at high risk for CVD were identified based on medical history, and clinical and physical findings. Factor analysis was performed on children's skinfold thicknesses, height, weight, and systolic and diastolic blood pressures, in order to produce a limited number of uncorrelated child CVD risk factors. Multiple regression analyses were then performed to determine other CVD markers associated with these Factors, independently for mothers and fathers. ^ Results. Factor analysis of children's measurements revealed three uncorrelated latent variables summarizing the children's CVD risk: Factor1: ‘Fatness’, Factor2: ‘Size and Maturity’, and Factor3: ‘Blood Pressure’, together accounting for the bulk of variation in children's measurements (86–89%). Univariate analyses showed that children from high CVD risk families did not differ from children of low risk families in occurrence of high blood pressure, overweight, biological maturity, acculturation score, or social and economic indicators. However, multiple regression using the factor scores (from factor analysis) as dependent variables, revealed that higher CVD risk in parents, was significantly associated with increased fatness and increased blood pressure in the children. Father's CVD risk status was associated with higher levels of body fat in his children and higher levels of blood pressure in sons. Mother's CVD risk status was associated with higher blood pressure levels in children, and occurrence of obesity in the mother associated with higher fatness levels in her children. ^ Conclusion. Occurrence of cardiovascular disease and its risk factors in parents of Mexican American children, may be used to identify children at potentially higher risk for developing CV disease in the future. Obesity in mothers appears to be an important marker for the development of higher levels of body fatness in children. ^

Associations between macronutrient intake and serum lipid profile depend on body fat in European adolescents: the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study

The present study aimed to investigate the relationships between macronutrient intake and serum lipid profile in adolescents from eight European cities participating in the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) cross-sectional study (2006–7), and to assess the role of body fat-related variables in these associations. Weight, height, waist circumference, skinfold thicknesses, total choles- terol, HDL-cholesterol (HDL-C), LDL-cholesterol, TAG, apoB and apoA1 were measured in 454 adolescents (44 % boys) aged 12·5–17·5 years. Macronutrient intake (g/4180 kJ per d (1000 kcal per d)) was assessed using two non-consecutive 24 h dietary recalls. Associations were evaluated by multi-level analysis and adjusted for sex, age, maternal education, centre, sum of four skinfolds, moderate-to-vigorous.

Secular trend in the development of fatness during childhood and adolescence

This study examined the development of fatness, as indexed by skinfold thickness, in healthy Caucasian children and adolescents residing in the same location in Canada in the 1960s and the 1990s. The data comes from two longitudinal studies, conducted approximately 30 years apart, of children aged 8-16 years. The first study (1964-1973) annually measured 207 males and 140 females. The second investigation (1991-1997) repeatedly measured 113 males and 115 females. Identical measurement tools and protocols were used for height, body mass, and skinfolds. Maturational age was estimated as a measure in years from age of peak height velocity. Males from the second investigation matured significantly (P < 0.05) earlier. Multilevel regression modeling was utilized to determine developmental curves for the individuals within the two populations. When differences in height, body mass, and maturity were controlled, skinfold thicknesses of the males and females in the second study were significantly greater (P < 0.05) than age- and sex-matched peers in the first study. This was not seen in models of the BMI. The results suggest that when maturity and size were controlled, the fatness of children and adolescents increased over 30 years. (C) 2002 Wiley-Liss, Inc.

Cardiorespiratory fitness and cardiometabolic risk factors in schoolchildren from Colombia: The FUPRECOL Study

The objectives of this study are to investigate the association between cardiorespiratory fitness and cardiovascular risk factors in schoolchildren and to evaluate the degree of association between overall and abdominal adiposity and cardiorespiratory fitness. A total of 1,875 children and adolescents attending public schools in Bogota, Colombia (56.2% girls; age range of 9–17.9 years). A cardiovascular risk score (Z-score) was calculated and participants were divided into tertiles according to low and high levels of overall (sum of the skinfold thicknesses) and abdominal adiposity. Schoolchildren with a high level of overall adiposity demonstrated significant differences in seven of the 10 variables analyzed (i.e. systolic and diastolic blood pressure, triglycerides, triglycerides/HDL-c ratio, total cholesterol, glucose and cardiovascular risk score). Schoolchildren with high levels of both overall and abdominal adiposity and low cardiorespiratory fitness had the least favorable cardiovascular risk factors score. These findings may be relevant to health promotion in Colombian youth.

Validity and reliability of the international fItness scale (IFIS) in a population-based sample of schoolchildren in Bogota, Colombia: The FUPRECOL study

The International FItness Scale (IFIS) is a self-reported measure of physical fitness that could easily. This scale has been validated in children, adolescents, and young adults; however, it is unknown whether the IFIS represents a valid and reliable estimate of physical fitness in Latino-American youth population. In the present study we aimed to examine the validity and reliability of the IFIS on a population-based sample of schoolchildren in Bogota, Colombia. Participants were 1,875 Colombian youth (56.2% girls) aged 9 to 17.9 years old. We measured adiposity markers (body fat, waist-to-height ratio, skinfold thicknesses and BMI), blood pressure, lipids profile, fasting glucose, and physical fitness level (self reported and measured). Also, a validated cardiometabolic risk index was used. An age- and sex-matched sample of 229 Schoolchildren originally not included in the study sample fulfilled IFIS twice for reliability purposes. Our data suggest that both measured and self-reported overall fitness were associated inversely with adiposity indicators and a cardiometabolic risk score. Overall, schoolchildren who self-reported “good” and “very good” fitness had better measured fitness than those who reported “very poor” and “poor” fitness (all p<0.001). Test–retest reliability of IFIS items was also good, with an average weighted Kappa of 0.811. Therefore, our findings suggest that self-reported fitness, as assessed by IFIS, is a valid, reliable, and health-related measure, and it can be a good alternative for future use in large studies with Latin-schoolchildren from Colombia.

Body composition and its relationship to metabolic risk factors in Asian children

Obesity is a major public health problem in both developed and developing countries. The body mass index (BMI) is the most common index used to define obesity. The universal application of the same BMI classification across different ethnic groups is being challenged due to the inability of the index to differentiate fat mass (FM) and fat�]free mass (FFM) and the recognized ethnic differences in body composition. A better understanding of the body composition of Asian children from different backgrounds would help to better understand the obesity�]related health risks of people in this region. Moreover, the limitations of the BMI underscore the necessity to use where possible, more accurate measures of body fat assessment in research and clinical settings in addition to BMI, particularly in relation to the monitoring of prevention and treatment efforts. The aim of the first study was to determine the ethnic difference in the relationship between BMI and percent body fat (%BF) in pre�]pubertal Asian children from China, Lebanon, Malaysia, the Philippines, and Thailand. A total of 1039 children aged 8�]10 y were recruited using a non�]random purposive sampling approach aiming to encompass a wide BMI range from the five countries. Percent body fat (%BF) was determined using the deuterium dilution technique to quantify total body water (TBW) and subsequently derive proportions of FM and FFM. The study highlighted the sex and ethnic differences between BMI and %BF in Asian children from different countries. Girls had approximately 4.0% higher %BF compared with boys at a given BMI. Filipino boys tended to have a lower %BF than their Chinese, Lebanese, Malay and Thai counterparts at the same age and BMI level (corrected mean %BF was 25.7�}0.8%, 27.4�}0.4%, 27.1�}0.6%, 27.7�}0.5%, 28.1�}0.5% for Filipino, Chinese, Lebanese, Malay and Thai boys, respectively), although they differed significantly from Thai and Malay boys. Thai girls had approximately 2.0% higher %BF values than Chinese, Lebanese, Filipino and Malay counterparts (however no significant difference was seen among the four ethnic groups) at a given BMI (corrected mean %BF was 31.1�}0.5%, 28.6�}0.4%, 29.2�}0.6%, 29.5�}0.6%, 29.5�}0.5% for Thai, Chinese, Lebanese, Malay and Filipino girls, respectively). However, the ethnic difference in BMI�]%BF relationship varied by BMI. Compared with Caucasians, Asian children had a BMI 3�]6 units lower for a given %BF. More than one third of obese Asian children in the study were not identified using the WHO classification and more than half were not identified using the International Obesity Task Force (IOTF) classification. However, use of the Chinese classification increased the sensitivity by 19.7%, 18.1%, 2.3%, 2.3%, and 11.3% for Chinese, Lebanese, Malay, Filipino and Thai girls, respectively. A further aim of the first study was to determine the ethnic difference in body fat distribution in pre�]pubertal Asian children from China, Lebanon, Malaysia, and Thailand. The skin fold thicknesses, height, weight, waist circumference (WC) and total adiposity (as determined by deuterium dilution technique) of 922 children from the four countries was assessed. Chinese boys and girls had a similar trunk�]to�]extremity skin fold thickness ratio to Thai counterparts and both groups had higher ratios than the Malays and Lebanese at a given total FM. At a given BMI, both Chinese and Thai boys and girls had a higher WC than Malays and Lebanese (corrected mean WC was 68.1�}0.2 cm, 67.8�}0.3 cm, 65.8�}0.4 cm, 64.1�}0.3 cm for Chinese, Thai, Lebanese and Malay boys, respectively; 64.2�}0.2 cm, 65.0�}0.3 cm, 62.9�}0.4 cm, 60.6�}0.3 cm for Chinese, Thai, Lebanese and Malay girls, respectively). Chinese boys and girls had lower trunk fat adjusted subscapular/suprailiac skinfold ratio compared with Lebanese and Malay counterparts. The second study aimed to develop and cross�]validate bioelectrical impedance analysis (BIA) prediction equations of TBW and FFM for Asian pre�]pubertal children from China, Lebanon, Malaysia, the Philippines, and Thailand. Data on height, weight, age, gender, resistance and reactance measured by BIA were collected from 948 Asian children (492 boys and 456 girls) aged 8�]10 y from the five countries. The deuterium dilution technique was used as the criterion method for the estimation of TBW and FFM. The BIA equations were developed from the validation group (630 children randomly selected from the total sample) using stepwise multiple regression analysis and cross�]validated in a separate group (318 children) using the Bland�]Altman approach. Age, gender and ethnicity influenced the relationship between the resistance index (RI = height2/resistance), TBW and FFM. The BIA prediction equation for the estimation of TBW was: TBW (kg) = 0.231�~Height2 (cm)/resistance (ƒ¶) + 0.066�~Height (cm) + 0.188�~Weight (kg) + 0.128�~Age (yr) + 0.500�~Sex (male=1, female=0) . 0.316�~Ethnicity (Thai ethnicity=1, others=0) �] 4.574, and for the estimation of FFM: FFM (kg) = 0.299�~Height2 (cm)/resistance (ƒ¶) + 0.086�~Height (cm) + 0.245�~Weight (kg) + 0.260�~Age (yr) + 0.901�~Sex (male=1, female=0) �] 0.415�~Ethnicity (Thai ethnicity=1, others=0) �] 6.952. The R2 was 88.0% (root mean square error, RSME = 1.3 kg), 88.3% (RSME = 1.7 kg) for TBW and FFM equation, respectively. No significant difference between measured and predicted TBW and between measured and predicted FFM for the whole cross�]validation sample was found (bias = �]0.1�}1.4 kg, pure error = 1.4�}2.0 kg for TBW and bias = �]0.2�}1.9 kg, pure error = 1.8�}2.6 kg for FFM). However, the prediction equation for estimation of TBW/FFM tended to overestimate TBW/FFM at lower levels while underestimate at higher levels of TBW/FFM. Accuracy of the general equation for TBW and FFM compared favorably with both BMI�]specific and ethnic�]specific equations. There were significant differences between predicted TBW and FFM from external BIA equations derived from Caucasian populations and measured values in Asian children. There were three specific aims of the third study. The first was to explore the relationship between obesity and metabolic syndrome and abnormalities in Chinese children. A total of 608 boys and 800 girls aged 6�]12 y were recruited from four cities in China. Three definitions of pediatric metabolic syndrome and abnormalities were used, including the International Diabetes Federation (IDF) and National Cholesterol Education Program (NCEP) definition for adults modified by Cook et al. and de Ferranti et al. The prevalence of metabolic syndrome varied with different definitions, was highest using the de Ferranti definition (5.4%, 24.6% and 42.0%, respectively for normal�]weight, overweight and obese children), followed by the Cook definition (1.5%, 8.1%, and 25.1%, respectively), and the IDF definition (0.5%, 1.8% and 8.3%, respectively). Overweight and obese children had a higher risk of developing the metabolic syndrome compared to normal�]weight children (odds ratio varied with different definitions from 3.958 to 6.866 for overweight children, and 12.640�]26.007 for obese children). Overweight and obesity also increased the risk of developing metabolic abnormalities. Central obesity and high triglycerides (TG) were the most common while hyperglycemia was the least frequent in Chinese children regardless of different definitions. The second purpose was to determine the best obesity index for the prediction of cardiovascular (CV) risk factor clustering across a 2�]y follow�]up among BMI, %BF, WC and waist�]to�]height ratio (WHtR) in Chinese children. Height, weight, WC, %BF as determined by BIA, blood pressure, TG, high�]density lipoprotein cholesterol (HDL�]C), and fasting glucose were collected at baseline and 2 years later in 292 boys and 277 girls aged 8�]10 y. The results showed the percentage of children who remained overweight/obese defined on the basis of BMI, WC, WHtR and %BF was 89.7%, 93.5%, 84.5%, and 80.4%, respectively after 2 years. Obesity indices at baseline significantly correlated with TG, HDL�]C, and blood pressure at both baseline and 2 years later with a similar strength of correlations. BMI at baseline explained the greatest variance of later blood pressure. WC at baseline explained the greatest variance of later HDL�]C and glucose, while WHtR at baseline was the main predictor of later TG. Receiver�]operating characteristic (ROC) analysis explored the ability of the four indices to identify the later presence of CV risk. The overweight/obese children defined on the basis of BMI, WC, WHtR or %BF were more likely to develop CV risk 2 years later with relative risk (RR) scores of 3.670, 3.762, 2.767, and 2.804, respectively. The final purpose of the third study was to develop age�] and gender�]specific percentiles of WC and WHtR and cut�]off points of WC and WHtR for the prediction of CV risk in Chinese children. Smoothed percentile curves of WC and WHtR were produced in 2830 boys and 2699 girls aged 6�]12 y randomly selected from southern and northern China using the LMS method. The optimal age�] and gender�]specific thresholds of WC and WHtR for the prediction of cardiovascular risk factors clustering were derived in a sub�]sample (n=1845) by ROC analysis. Age�] and gender�]specific WC and WHtR percentiles were constructed. The WC thresholds were at the 90th and 84th percentiles for Chinese boys and girls, respectively, with sensitivity and specificity ranging from 67.2% to 83.3%. The WHtR thresholds were at the 91st and 94th percentiles for Chinese boys and girls, respectively, with sensitivity and specificity ranging from 78.6% to 88.9%. The cut�]offs of both WC and WHtR were age�] and gender�]dependent. In conclusion, the current thesis quantifies the ethnic differences in the BMI�]%BF relationship and body fat distribution between Asian children from different origins and confirms the necessity to consider ethnic differences in body composition when developing BMI and other obesity index criteria for obesity in Asian children. Moreover, ethnicity is also important in BIA prediction equations. In addition, WC and WHtR percentiles and thresholds for the prediction of CV risk in Chinese children differ from other populations. Although there was no advantage of WC or WHtR over BMI or %BF in the prediction of CV risk, obese children had a higher risk of developing the metabolic syndrome and abnormalities than normal�]weight children regardless of the obesity index used.