Waist circumference values in Spanish children--gender related differences

Children's foot parameters and basic anthropometry - do arch height and midfoot width change?

The aims of this study were as follows: (1) to assess how foot posture and morphology assessments change according to body mass index (BMI) status; (2) to determine which body composition parameter (BMI or waist circumference) correlates better with the foot posture index (FPI), arch height index (AHI), and midfoot width (MFW) in children. Foot morphometry (FPI, AHI, and MFW) and body composition (BMI and waist circumference (WC)) were assessed in a cross-sectional study of 575 children (mean age = 7.42 ± 1.67 years; 53.27% female). When comparing BMI groups, an increase of 8.3% in AHI and 13.6% in MFW (both p < 0.0001) was seen. In linear regression analyses, BMI and WC were positively associated with MFW explaining together 64.8% of its variance. Noteworthy, MFW is the most related to body composition parameters.

CONCLUSION

Foot morphology assessed by FPI, AHI, and MFW differs among BMI categories in children. Noteworthy, WC correlates better with foot measures than does the more commonly used BMI, and more importantly the MFW is the foot measure best explained by children's body weight. Since foot morphometry is different among different BMI groups, children would benefit from shoes with different patterns (thinner and wider), as well as a good system to adjust midfoot height.

WHAT IS KNOWN

• Children who are overweight and obese have flatter feet, when assessed using footprints. • Up to 72% of people have incorrectly fitted shoes.

WHAT IS NEW

• Children with underweight have thinner and flatter feet than children with normal weight, while children with overweight and obesity have wider and higher arched feet. • Body weight is related to foot shape, which has relevance for footwear manufacturers.

Waist circumference and waist-to-height ratio in 7-year-old children-WHO Childhood Obesity Surveillance Initiative

Childhood obesity is a serious global health problem. Waist circumference (WC) and waist-to-height ratio (WHtR) reflect body fat distribution in children. The objectives of this study were to assess WC and WHtR in 7-year-old children and to determine body mass index (BMI), WC, and WHtR differences in children from 10 selected countries across Europe (Bulgaria, Czechia, Greece, Ireland, Latvia, Lithuania, North Macedonia, Norway, Spain, and Sweden) participating in the World Health Organization (WHO) Europe Childhood Obesity Surveillance Initiative (COSI). The 50th and 90th percentile of WC (according to COSI and "Identification and prevention of Dietary- and lifestyle-induced health EFfects In Children and infantS" (IDEFICS) cutoff values) and WHtR above 0.5 were used as measures of abdominal obesity in a unique sample of 38,975 children aged 7.00-7.99 years. Southern European countries, including Greece and Spain, showed significantly higher BMI, WC, and WHtRin both genders (p < 0.0001) than Eastern and Northern Europe. The highest values for WC were observed in Greece (60.8 ± 7.36 cm boys; 60.3 ± 7.48 cm girls), North Macedonia (60.4 ± 7.91 cm boys; 59.0 ± 8.01 cm girls), and Spain (59.7 ± 6.96 cm boys; 58.9 ± 6.77 cm girls). WC and WHtRin may add an information about the occurrence of central obesity in children.

Waist Circumference Percentiles and Cut-Off Values for Obesity in a Large Sample of Students from 6 To 10 Years Old Of The São Paulo State, Brazil

Fundamento

A prevalência da obesidade vem aumentando sistematicamente na população, inclusive nas crianças e adolescentes, ao redor do mundo.

Objetivos

Descrever curvas percentílicas de referência para a circunferência abdominal (CA) nas crianças brasileiras e fornecer pontos de corte da CA para identificar crianças com risco de obesidade.

Métodos

Um estudo multicêntrico, prospectivo, tranversal foi realizado em crianças com idades entre 6 e 10 anos, matriculadas no ensino fundamental de escolas públicas e particulares de 13 cidades do estado de São Paulo. A estatura, o peso e a CA foram medidos em duplicata em 22.000 crianças (11.199 meninos). Para estabelecer o melhor ponto de corte da CA para o diagnóstico da obesidade, foram calculadas curvas ROC com crianças classificadas como com peso normal e obesas, de acordo com as curvas do IMC, estratificadas por gênero e idade, e o índice Youden foi utilizado como a eficácia potencial máxima desse biomarcador. Valores de p < 0,05 foram considerados estatisticamente significativos.

Resultados

Os valores da CA aumentaram com a idade, tanto nos meninos quanto nas meninas. A prevalência de obesidade em cada grupo variou de 17% (6 anos de idade) a 21,6 % (9 anos de idade), dentre os meninos, e de 14,1% (7 anos de idade) a 17,3 % (9 anos de idade), dentre as meninas. As análises ROC mostraram o percentil 75 como ponto de corte para o risco de obesidade, e o diagnóstico de obesidade está classificado no percentil 85 ou acima.

Conclusão

Curvas de referência da CA específicas para idade e sexo em crianças brasileiras e pontos de corte para o risco de obesidade podem ser usados em triagem nacional e estudos intervencionais para reduzir a carga da obesidade no Brasil. (Arq Bras Cardiol. 2020; 114(3):530-537)

Waist circumference, waist-to-hip ratio, and waist-to-height ratio reference percentiles for abdominal obesity among Macedonian adolescents

Introduction

Background: the goal of this study was to define waist circumference (WC), waist-to-hip ratio (WHR) and waist-to-height ratio (WHRt) smoothed reference percentiles for assessing abdominal obesity in Macedonian adolescents aged 11 to 18 years in order to investigate possible obesity cut-offs of WHR and WHtR, and to compare WC percentiles with those of other adolescents. Methods: the research was conducted on a sample of 2,490 adolescents of the Republic of Macedonia aged 11 to 18 years: 1,288 males and 1,202 females. Weight, height, body mass index (BMI), WC, hip circumference (HC), WHR and WHtR were measured and percentiles were calculated using Cole's Lambda, Mu and Sigma (LMS) method. The relation between WHR, WHtR and general obesity, as defined by the International Obesity Task Force, was investigated with a receiver operating characteristic (ROC) analysis. Results: the boys had statistically significant higher values in all anthropometric measures except in HC, where statistically significant gender differences were not found. BMI, WC, and HC showed an increasing trend with age. The WHtR variable is a better indicator for assessing general obesity in both boys and girls (AUC, 95 % CI: 0.905-0.928) than WHR, which showed lower AUC values (95 % CI: 0.697-0.734) in predicting IOTF obesity; the WHtR cut-off of 0.5 had a sensitivity of 74 % and a specificity of 92 % for both genders and all age groups. Conclusions: the obtained reference percentile curves can be used temporarily for early detection of abdominal obesity among Macedonian adolescents aged 11 to 18 years; a WHtR of 0.5 may also be used as an obesity threshold in these age groups.

Children with type 1 diabetes have elevated high-sensitivity C-reactive protein compared with a control group

INTRODUCTION

Our objective was to compare high-sensitivity C-reactive protein (hsCRP) levels in children with type 1 diabetes, healthy controls, and children with obesity. Additionally, we aimed to analyze the association between hsCRP levels and glycemic control measured by glycohemoglobin A (HbA1c) and anthropometric and biochemical variables.

RESEARCH DESIGN AND METHODS

We conducted a non-randomized descriptive study of children with type 1 diabetes matched for sex and age with a control group and group with obesity. We recorded anthropometric parameters and studied variables related to diabetes, blood pressure, lipid profile, and HbA1c. hsCRP was measured by ELISA.

RESULTS

We included 49 children with type 1 diabetes, 46 controls, and 40 children with obesity. hsCRP levels were significantly higher in the group with type 1 diabetes compared with controls and nearly significantly lower than in the group comprising children with obesity. We found no correlation between hsCRP and HbA1c and characteristics of type 1 diabetes with the exception of albumin to creatinine ratio. Statistically significant association was found between hsCRP and body mass index (BMI) and waist circumference Z-score.

CONCLUSIONS

The higher hsCRP levels observed in children with type 1 diabetes compared with a control group with a similar BMI suggest a basal inflammatory state that could increase cardiovascular risk. The main factors related to hsCRP are BMI and waist circumference, so obesity prevention should be a priority when performing follow-up in children with type 1 diabetes.

Percentile Curves for Body-Mass Index, Waist Circumference, Waist-To-Height Ratio and Waist-To-Height Ratio(Exp) in Croatian Adolescents

PURPOSE

The main purpose of the present study was to establish percentile curves for body-mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR) and WHtR(exp) in adolescents.

METHODS

In this cross-sectional study, we recruited 1036 secondary-school students aged 15 to 18 years from eight randomly selected schools (55.3% girls). BMI, WC, WHtR and WHtR(exp) were calculated using standardized measuring protocol. The sex- and age-specific smoothed percentile curves with 5th, 10th, 25th, 50th, 75th, 90th, and 95th percentile for each anthropometric measure were constructed using Cole's LMS method.

RESULTS

In boys, both BMI and WC percentile curves increased by age, yet the 95th percentile curve for WHtR and WHtR(exp) decreased by age. In girls, the 95th percentile curve for BMI remained unchanged through the age of 15 to 18 years, yet the 90th and 95th percentile curves for WC and WHtR decreased by age.

CONCLUSION

This is the first study in Croatia to establish combined BMI, WC, WHtR and WHtR(exp) percentile curves and add some new insight on anthropometric measures in 15- to 18-year-old adolescents.

Waist-to-height ratio as a risk marker for metabolic syndrome in childhood. A meta-analysis

BACKGROUND

Individuals with abdominal obesity have a higher cardiovascular risk, regardless of the degree of global overweight.

OBJECTIVE

To estimate the accuracy of the Waist/height ratio (WtHR) as a risk marker for metabolic syndrome (MS) in children or adolescents.

METHODS

Published cohort or cross-sectional studies (Pubmed, Embase-SCOPUS and CINAHL) were searched, with no limits of time. Studies providing Waist/height ratio and clustered criteria of metabolic syndrome were included.

RESULTS

Thirty-one studies (66,912 subjects) were selected. Overall, a high WtHR (≥0.5) was associated with a four-fold increased risk of clustered criteria of MS (odds ratio [OR] 4.15, 95% confidence interval [95% CI]: 2.69 to 6.42) and two-fold increased risk when adjusted by general obesity (adjusted OR 2.26, 95% CI: 1.29 to 3.98). The WtHR, as a quantitative measure, showed a pooled area under the curve of 0.76 (95% CI: 0.71 to 0.80) and, as a dichotomous measure, with a cut-off point close to 0.5, a sensitivity of 60% (95% CI: 50% to 68.8%) and a specificity of 79% (95% CI: 71.6% to 83.9%).

CONCLUSIONS

Measuring WtHR may be considered in regular health checks of children and adolescents, as it can measure cardiovascular risk regardless of the degree of general obesity.

Comparisons of Waist Circumference Measurements at Five Different Anatomical Sites in Chinese Children

This study compared the waist circumference (WC) measurements of Chinese children at different sites to determine the relationship between WC measurements and body fat. WC was measured at five sites in 255 subjects aged 9-19 years: immediately below the lowest rib (WC1), at the narrowest waist (WC2), the midpoint between the lowest rib and the iliac crest (WC3), 1 cm above the umbilicus (WC4), and immediately above the iliac crest (WC5). Body fat mass (FM), body fat percentage (% BF), body fat mass in the trunk (FM in the trunk), and fat percentage in the trunk (% BF in the trunk) were determined by dual-energy X-ray absorptiometry. The WCs were then compared through ANOVA with repeated measurement. The relationship of WC of each site with FM, % BF, FM in the trunk, and % BF in the trunk was examined through partial correlation. The WCs exhibited the following pattern: WC2 < WC1 < WC3 < WC4 < WC5 (p < 0.001) in males and WC2 < WC1 < WC4, WC3 < WC5 (p < 0.001) in females. The measured WCs were strongly correlated with FM, % BF, FM in the trunk, and % BF in the trunk. The WC measurements at five commonly used sites among Chinese children are different from one another. Results indicate that standardizing the anatomic point for the WC measurements is necessary.

Dietary fructose intake in obese children and adolescents: relation to procollagen type III N-terminal peptide (P3NP) and non-alcoholic fatty liver disease

BACKGROUND

Excessive use of fructose has been incriminated as a risk factor for hepatic steatosis. Procollagen type III N-terminal peptide (P3NP) is a marker for steatohepatitis. Thus, we aimed to assess fructose intake in obese children and its relation to nonalcoholic fatty liver disease (NAFLD) and P3NP.

METHODS

Fifty-five obese children were compared to 30 controls. All were subjected to dietary fructose and anthropometric assessment, fasting blood sugar (FBS), fasting insulin (FI) and homeostasis model assessment of insulin resistance (HOMA-IR), lipid profile, uric acid, alanine aminotransferase (ALT), P3NP and abdominal ultrasound.

RESULTS

Patients had higher fructose intake which was associated with increased NAFLD grade. There was an increase in P3NP with increased NAFLD grade. P3NP correlated positively with fructose intake (processed sources and total) and caloric intake.

CONCLUSIONS

High fructose intake is associated with NAFLD and P3NP may serve as a marker of NAFLD in obese children with a proposed cutoff value of 8.5 ng/mL.

[Effects of growth hormone treatment on anthropometrics, metabolic risk, and body composition variables in small for gestational age patients]

INTRODUCTION AND OBJECTIVES

Small for gestational age (SGA) children without catch-up growth can benefit from treatment with growth hormone (rhGH). However, they should be monitored very closely because they are at increased risk of metabolic syndrome.

MATERIAL AND METHOD

A group of 28 SGA children with a mean age of 8.79 years and undergoing treatment with rhGH were selected for evaluation. Over the course of 4 years, an annual evaluation was performed on the anthropometric variables (weight, height, body mass index [BMI], growth rate, blood pressure and waist perimeter), metabolic risk variables (glycaemia, glycosylated haemoglobin, cholesterol ratio, insulinaemia, insulin-like growth factor 1[IGF1], IGF binding protein-3 [IGFBP-3], IGF1/IGFBP3 ratio, and HOMA index), and body composition variables.

RESULTS

Treatment with rhGH was associated with a significant increase in height (-2.76±.11 SD to -1.53±.17 SD, P=.000), weight (-1.50±.09 SD to -1.21±.13 SD; P=.016), and growth rate (-1.43±.35 SD to .41±.41 SD; P=.009), without a corresponding change in the BMI. Insulinaemia (9.33±1.93mU/ml to 16.55±1.72mU/ml; P=.044) and the HOMA index (3.63±.76 to 6.43±.67; P=.042) increased, approaching insulin resistance levels. No changes were observed in the lipid profile. Body composition changes were observed, with a significant increase in lean mass (73.19±1.26 to 78.74±1.31; P=.037), and a reduction of fat mass (26.81±1.26 to 21.26±1.31; P=.021).

CONCLUSION

Treatment with rhGH is effective for improving anthropometric variables in SGA patients who have not experienced a catch-up growth. It also produces changes in body composition, which may lead to a reduction in risk of metabolic syndrome. However, some insulin resistance was observed. It is important to follow up this patient group in order to find out whether these changes persist into adulthood.

Waist Circumference Percentiles in Indigenous Argentinean School Children Living at High Altitudes

BACKGROUND

Central obesity is associated with increased risk of type 2 diabetes.

OBJECTIVES

The study objectives were to develop waist circumference (WC) percentiles, to determine if WC is associated with metabolic risk, and to compare our WC percentiles with those reported in the 2007-2010 National Health and Nutrition Examination Survey (NHANES).

METHODS

A cross-sectional study of 1232 children (606 boys ) 5-14 years was performed from 2011 to 2014 in indigenous Koya children from northwestern Argentina. Anthropometric characteristics, glucose, lipids, and insulin levels were measured. Sex-specific reference percentiles were computed using the Lambda-Mu-Sigma (LMS) method. We obtained 2007-2010 NHANES data for comparison with our results.

RESULTS

Compared with the NHANES 90th percentile, WC values for children in this study were lower by an average of 11.05 cm for girls and 12.66 cm for boys. The prevalence of low high-density lipoprotein cholesterol (HDL-C) was 11.8% in children with WC ≤50th percentile, 10.3% in children with WC >50th-70th percentile, 17.5% in children with WC >70th-90th percentile, and 21.3% in children with WC >90th percentile. The prevalence of high triglycerides (TG) was 19.5% in children with WC ≤50th percentile, 19.9% in children with WC >50th-70th percentile, 28.8% in children with WC >70th-90th percentile, and 39.7% in children with WC >90th percentile. Multiple logistic regression analyses showed that high TG values (>150 mg/dL) were significantly associated with WC [odds ratio (OR)] 1.05; 95% confidence interval (CI) 1.03-1.08; and low HDL-C values (<35 mg/dL) were significantly associated with WC (OR 1.04; 95% CI 1.01-1.06), adjusted for age and gender.

CONCLUSION

We present for the first time WC reference data for indigenous Koya children ages 5-14 years. There was a significant association between WC and dyslipidemia in this community. Compared with the NHANES WC percentiles, our WC values were lower. These differences possibly reflect ethnicity or the lower prevalence of obesity.

Development of waist circumference percentiles for Japanese children and an examination of their screening utility for childhood metabolic syndrome: a population-based cross-sectional study

BACKGROUND

In Japan, waist circumference (WC) percentiles to screen for childhood metabolic syndrome (MetS) are unavailable. The objectives of this study were to develop WC and WC-to-height ratio (WC/Ht) percentile curves by age and sex for Japanese children, and to test their utility in screening for MetS in children with obesity who are otherwise healthy.

METHODS

The WC and WC/Ht percentiles were developed using the LMS method of summarizing growth standards, which monitors changing skewness (L), medians (M), and coefficients of variation (S) in childhood distributions. A representative dataset was used, which consisted of 3,634 boys and 3,536 girls aged 4.5-12.75 years in Shizuoka prefecture, Japan, between 2010 and 2012. Children who were obese (355 boys and 230 girls) aged 6-12 years from Osaka prefecture, Japan, were screened for childhood MetS using the new percentiles and the International Diabetes Federation's (IDF's) definition of MetS.

RESULTS

The number of participants with certain metabolic abnormalities (high systolic and diastolic blood pressure, and a high level of triglycerides) was significantly higher in boys aged 10-12 years, with a WC ≥ 90th percentile, than among those with a WC < 90th percentile. None of the participants with a WC < 90th percentile exhibited two or more metabolic abnormalities, regardless of their age or sex. Among the participants aged 10-12 years, 11.4 % of boys and 4.4 % of girls with a WC ≥ 90th percentile were diagnosed with MetS.

CONCLUSIONS

The new percentiles may have a certain level of potential to screen Japanese children for childhood MetS in accordance with the IDF definition.

Waist Circumferences of Chilean Students: Comparison of the CDC-2012 Standard and Proposed Percentile Curves

The measurement of waist circumference (WC) is considered to be an important means to control overweight and obesity in children and adolescents. The objectives of the study were to (a) compare the WC measurements of Chilean students with the international CDC-2012 standard and other international standards, and (b) propose a specific measurement value for the WC of Chilean students based on age and sex. A total of 3892 students (6 to 18 years old) were assessed. Weight, height, body mass index (BMI), and WC were measured. WC was compared with the CDC-2012 international standard. Percentiles were constructed based on the LMS method. Chilean males had a greater WC during infancy. Subsequently, in late adolescence, males showed values lower than those of the international standards. Chilean females demonstrated values similar to the standards until the age of 12. Subsequently, females showed lower values. The 85th and 95th percentiles were adopted as cutoff points for evaluating overweight and obesity based on age and sex. The WC of Chilean students differs from the CDC-2012 curves. The regional norms proposed are a means to identify children and adolescents with a high risk of suffering from overweight and obesity disorders.

Percentile reference values for anthropometric body composition indices in European children from the IDEFICS study

INTRODUCTION

To characterise the nutritional status in children with obesity or wasting conditions, European anthropometric reference values for body composition measures beyond the body mass index (BMI) are needed. Differentiated assessment of body composition in children has long been hampered by the lack of appropriate references.

OBJECTIVES

The aim of our study is to provide percentiles for body composition indices in normal weight European children, based on the IDEFICS cohort (Identification and prevention of Dietary- and lifestyle-induced health Effects in Children and infantS).

METHODS

Overall 18,745 2.0-10.9-year-old children from eight countries participated in the study. Children classified as overweight/obese or underweight according to IOTF (N=5915) were excluded from the analysis. Anthropometric measurements (BMI (N=12 830); triceps, subscapular, fat mass and fat mass index (N=11,845-11,901); biceps, suprailiac skinfolds, sum of skinfolds calculated from skinfold thicknesses (N=8129-8205), neck circumference (N=12,241); waist circumference and waist-to-height ratio (N=12,381)) were analysed stratified by sex and smoothed 1st, 3rd, 10th, 25th, 50th, 75th, 90th, 97th and 99th percentile curves were calculated using GAMLSS.

RESULTS

Percentile values of the most important anthropometric measures related to the degree of adiposity are depicted for European girls and boys. Age- and sex-specific differences were investigated for all measures. As an example, the 50th and 99th percentile values of waist circumference ranged from 50.7-59.2 cm and from 51.3-58.7 cm in 4.5- to <5.0-year-old girls and boys, respectively, to 60.6-74.5 cm in girls and to 59.9-76.7 cm in boys at the age of 10.5-10.9 years.

CONCLUSION

The presented percentile curves may aid a differentiated assessment of total and abdominal adiposity in European children.

Percentis para o perímetro de cintura de adolescentes do município do Rio de Janeiro

OBJETIVO: Descrever o perímetro da cintura e apresentar estimativas de pontos críticos para classificação de risco e alto risco de excesso de gordura abdominal segundo sexo e faixa etária. MÉTODOS: Foi estudada uma amostra probabilística de adolescentes (n=3 . 175) da rede pública de ensino do Rio de Janeiro. O perímetro da cintura foi aferido no ponto médio entre a borda inferior da costela e a crista ilíaca. Os percentis de perímetro da cintura estudados foram estimados segundo método LMS (Lambda, Mu, Sigma) proposto por Cole em 1990. Os pontos de corte adotados para definição de risco e alto risco de excesso de gordura abdominal foram os propostos por Jolliffe & Janssen em 2007. RESULTADOS: Comparando os valores estimados, meninas apresentaram valores de perímetro da cintura maiores que os de meninos para todos os percentis (exceto para o P90) em todas as idades. Os valores críticos estimados foram menores entre as meninas e aumentaram com a idade em ambos os sexos. Em geral, para ambos os sexos, os valores estimados foram menores do que os propostos pela referência adotada. CONCLUSÃO: Os achados ratificam a importância da aferição dessa medida em adolescentes, sendo apresentados pontos críticos de perímetro da cintura para classificação antropométrica desse grupo populacional segundo essa medida, o que até o momento não havia sido proposto com base em dados de adolescentes brasileiros.

Waist circumference, waist-to-hip ratio and waist-to-height ratio reference percentiles for abdominal obesity among Greek adolescents

BACKGROUND

Indices predictive of adolescent central obesity include waist circumference (WC), waist-to-hip ratio (WHR) and waist-to-height ratio (WHtR). Such reference data are lacking for Greek adolescents. The aim of this study was to develop age- and gender-specific WC, WHR and WHtR smoothed reference percentiles for abdominal obesity among Greek adolescents aged 12-17 years, to investigate possible obesity cut-offs of WHR and WHtR and to compare WC percentiles to other adolescent populations.

METHODS

A representative sample of 1610 high school adolescents (42.2% boys, 57.8% girls; mean age ± sd 14.4 ± 1.72 years) participated in this cross-sectional study in Attica, Greece, in 2013. Weight, height, body mass index (BMI), WC, hip circumference (HC), WHR and WHtR were measured and percentiles were calculated using the LMS method. The relation between WHR, WHtR and general obesity, as defined by the International Obesity Task Force, was investigated with receiver operating characteristic (ROC) analysis. The discriminating power of WHR and WHtR was expressed as area under the curve (AUC). Greek adolescents' WC measurements at the 50th and 90th percentile were compared with their counterparts' smoothed percentiles from Norway, Turkey, Poland, South India, Germany and Kuwait.

RESULTS

Boys had significantly higher mean in all measures than girls, except for BMI where there was no statistical difference in terms of gender. BMI, WC and HC showed an increasing trend with age. WC leveled off in both genders at the age of 17 years. WHR and WHtR showed a continuous decrease with advancing age. WHtR was a better predictor for general obesity in both boys and girls (AUC 95% CI 0.945-0.992) than the WHR (AUC 95% CI 0.758-0.870); the WHtR cut-off of 0.5 had sensitivity 91% and specificity 95% for both genders and all age groups combined. International comparisons showed that Greek adolescents had relatively high levels of abdominal obesity in early-middle adolescence but this did not persist at the age of 17 years.

CONCLUSIONS

These reference percentile curves could be used provisionally for early detection of abdominal obesity in Greek adolescents aged 12-17 years; WHtR of 0.5 could also be used as a threshold for obesity in this age group.

Height, weight, body composition, and waist circumference references for 7- to 17-year-old children from rural Portugal

The purpose of this study was (1) to develop references of height, weight, body mass index (BMI), waist circumference and body fat for rural Portuguese children and adolescents and (2) to compare these results with other international references. The sample comprised 3094 children and adolescents aged 7-17 years from Vouzela, a central region in Portugal. Height, weight, BMI, waist circumference and body fat were measured. Centile curves were constructed using the LMS method. The Vouzela sample showed similar height median values compared to Centers for Disease Control and Prevention (CDC) and World Health Organization (WHO) percentile curves but greater values for weight and BMI. Percent body fat 50th percentile was greater in Vouzela children and adolescents compared to their international peers, except for boys aged 8-12 years. Boys' waist circumference median values were similar to those from the USA, whilst girls were similar until 12 years of age, after which the differences increased with age. The percentile curves constructed provide population specific references for growth and body composition of children and adolescents from rural Portugal. It is expected that they will be a useful tool for clinical and public health settings in rural Portugal.

Anthropometry and physical activity level in the prediction of metabolic syndrome in children

OBJECTIVE

To evaluate the effectiveness of anthropometric measures and physical activity level in the prediction of metabolic syndrome (MetS) in children.

DESIGN

Cross-sectional study with children from public and private schools. Children underwent an anthropometric assessment, blood pressure measurement and biochemical evaluation of serum for determination of TAG, HDL-cholesterol and glucose. Physical activity level was calculated and number of steps per day obtained using a pedometer for seven consecutive days.

SETTING

Viçosa, south-eastern Brazil.

SUBJECTS

Boys and girls (n 187), mean age 9·90 (SD 0·7) years.

RESULTS

Conicity index, sum of four skinfolds, physical activity level and number of steps per day were accurate in predicting MetS in boys. Anthropometric indicators were accurate in predicting MetS for girls, specifically BMI, waist circumference measured at the narrowest point and at the level of the umbilicus, four skinfold thickness measures evaluated separately, the sum of subscapular and triceps skinfold thickness, the sum of four skinfolds and body fat percentage.

CONCLUSIONS

The sum of four skinfolds was the most accurate method in predicting MetS in both genders.

Increased leptin/adiponectin ratio and free leptin index are markers of insulin resistance in obese girls during pubertal development

BACKGROUND

Modifications in body fat in obese patients during puberty determine changes in adipokines that affect insulin sensitivity.

AIMS

We hypothesized that the leptin/adiponectin (L/A) ratio and free leptin index (FLI) are good markers of insulin resistance (IR) and total body fat (TBF) during pubertal development.

METHODS

A prospective study of 32 obese girls (OG) and age-matched control girls (CG) was performed. OG were divided into those that maintained a weight loss (WL) of >1 SD of initial body mass index (BMI) (WL group, n = 25) and those without WL (NWL group, n = 7). Oral glucose tolerance tests (OGTT) were performed to evaluate IR. Correlations of adipokines, L/A, and FLI with BMI, waist circumference, percentage of TBF (%TBF) and IR were performed over pubertal development.

RESULTS

The L/A ratio and FLI were increased in OG at baseline. Both indexes decreased in the WL group as puberty progressed, with no change in CG or NWL. In the WL group, a correlation between L/A and FLI with OGTT and %TBF, and L/A and homeostasis model assessment (HOMA) was found throughout the study.

CONCLUSION

The L/A ratio and FLI are good markers to follow changes in IR and %TBF after WL during puberty. Insulin more accurately reflects the changes in IR than HOMA.

Methodologies to assess paediatric adiposity

INTRODUCTION

Childhood obesity is associated with increased risk of adult obesity, cardiovascular disease, diabetes and cancer. Appropriate techniques for assessment of childhood adiposity are required to identify children at risk. The aim of this review was to examine core clinical measurements and more technical tools to assess paediatric adiposity.

METHODS

The online databases PubMed, CINALH and EMBASE were searched and the abstracts identified were reviewed to determine appropriate studies. Their reference lists were also searched to identify further eligible studies. Publications were included if they described childhood measurement techniques or involved validation.

RESULTS AND DISCUSSION

There are many body composition assessment tools available, none of which are direct. Each technique has limitations and a combination of methods may be used. The main clinical techniques are weight, height, body mass index (BMI) and circumferences which provide sufficient information to enable classification of overweight or obesity when growth centile charts and ratios are employed. Further investigation depends on resources available and examiner skill. Skinfold thicknesses are cost-effective but require technical training and only measure subcutaneous fat. Dual energy X-ray absorptiometry (DEXA), air displacement plethysmography (ADP), magnetic resonance imaging (MRI) and computed tomography (CT) are more costly and intensive, requiring the child to remain still for longer periods. DEXA and ADP are capable of accurately measuring adiposity but are unable to distinguish between fat depots. MRI and CT can distinguish intra-abdominal from subcutaneous adiposity and are considered gold standards, but CT is unsuitable for adiposity measurement in children due to high levels of radiation exposure. Ultrasound is a promising technique capable of measuring intra-abdominal adiposity in children but requires further validation.

CONCLUSION

The core clinical measurements of weight, height, BMI and circumferences are sufficient to enable diagnosis of paediatric overweight and obesity while more technical tools provide further insight.

Novel modeling of reference values of cardiovascular risk factors in children aged 7 to 20 years

BACKGROUND AND OBJECTIVE

Most of the cardiovascular risk factors strongly associated with obesity and overweight vary with age and gender. However, few reference values are available for healthy European children. Our objective was to establish pediatric reference ranges for waist circumference, systolic and diastolic blood pressures, fasting lipid levels (total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglycerides), glucose, and insulin.

METHODS

A representative sample of 1976 healthy French individuals (1004 female participants and 972 male participants) aged 7 to 20 years was used to obtain age- and gender-specific normal ranges for each of the above-listed cardiovascular risk factors, based on the Royston and Wright method.

RESULTS

Mean waist circumference increased with age in both genders and was slightly higher in males than in females. Whereas systolic blood pressure increased gradually with age, with the increase being steeper in males than in females, no gender effect was found for diastolic blood pressure, which was therefore modeled after pooling males and females. Total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglyceride values varied little with age and gender. Glucose and insulin levels revealed pubertal peaks, which were sharper in females than in males, reflecting the normal insulin resistance during puberty.

CONCLUSIONS

These ranges can be used as references for European children to monitor cardiovascular risk factors and to plan interventions and education programs.

Waist circumference percentiles for Portuguese children and adolescents aged 10 to 18 years

The purposes of this study were to develop age- and sex-specific waist circumference reference data for Portuguese children and adolescents aged 10-18 years and to compare them with those from other countries. This was a school-based study performed in Portugal. A total of 22,003 children and adolescents aged 10-18 years were included in the study. Smoothed sex- and age-specific 5th, 10th, 25th, 50th, 75th, 90th, and 95th percentile curves of waist circumference were estimated using Cole's lambda-mu-sigma method. Waist circumference values increased with age in both boys and girls, and boys had higher values than girls at every age and percentile. In both sexes, the Portuguese values in the 90th percentile were closer to the Bolivian values and considerably lower than those of the American children for all age groups.

CONCLUSION

The data presented provide information for abdominal risk assessment and clinical and lifestyle intervention; our results also provide useful baseline data information for the implementation of a surveillance system required to monitor trends and factors associated with abdominal obesity in children and adolescents.

Waist circumference, waist-hip ratio and waist-height ratio percentiles and central obesity among Pakistani children aged five to twelve years

Background

Central obesity has been associated with the risk of cardiovascular and metabolic disease in children and anthropometric indices predictive of central obesity include waist circumference (WC), waist-hip ratio (WHR) and waist-height ratio (WHtR). South Asian children have higher body fat distribution in the trunk region but the literature regarding WC and related indices is scarce in this region. The study was aimed to provide age- and gender-specific WC, WHR and WHtR smoothed percentiles, and to explore prevalence and correlates of central obesity, among Pakistani children aged five to twelve years.

Methods

A population-based cross-sectional study was conducted with a representative multistage random cluster sample of 1860 primary school children aged five to twelve years in Lahore, Pakistan. Smoothed percentile curves were constructed for WC, WHR and WHtR by the LMS method. Central obesity was defined as having both age- and gender-specific WC percentile ≥90^th and WHtR ≥0.5. Chi-square test was used as the test of trend. Multivariate logistic regression was used to quantify the independent predictors of central obesity and adjusted odds ratios (aOR) with 95% CI were obtained. Linear regression was used to explore the independent determinants of WC and WHtR. Statistical significance was considered at P < 0.05.

Results

First ever age- and gender-specific smoothed WC, WHR and WHtR reference curves for Pakistani children aged five to twelve years are presented. WC increased with age among both boys and girls. Fiftieth WC percentile curves for Pakistani children were higher as compared to those for Hong Kong and British children, and were lower as compared to those for Iranian, German and Swiss children. WHR showed a plateau pattern among boys while plateau among girls until nine years of age and decreased afterwards. WHtR was age-independent among both boys and girls, and WHtR cut-off of ≥0.5 for defining central obesity corresponded to 85^th WHtR percentile irrespective of age and gender. Twelve percent children (95% CI 10.1-13.0) had a WC ≥90^th percentile and 16.5% children (95% CI 14.7-18.1) had a WHtR ≥0.5 while 11% children (95% CI 8.9-11.6) had both WC ≥90^th percentile and WHtR ≥0.5. Significant predictors of central obesity included higher grade, urban area with high socioeconomic status (SES), high-income neighborhood and higher parental education. Children studying in higher grade (aOR 5.11, 95% CI 1.76-14.85) and those living in urban area with high SES (aOR 82.34, 95% CI 15.76-430.31) showed a significant independent association. Urban area with high SES and higher parental education showed a significant independent association with higher WC and higher WHtR while higher grade showed a significant independent association with higher WC.

Conclusions

Comprehensive worldwide reference values are needed to define central obesity and the present study is the first one to report anthropometric indices predictive of central obesity for Pakistani school-aged children. Eleven percent children were centrally obese and strong predictors included higher grade, urban area with high SES and higher parental education. These findings support the need for developing a National strategy for childhood obesity and implementing targeted interventions, prioritizing the higher social class and involving communities.

Comparison of the performance of two measures of central adiposity among apparently healthy Nigerians using the receiver operating characteristic analysis

OBJECTIVE

To compare the performance of waist circumference (WC) and waist-to-hip ratio (WHR) in predicting the presence of cardiovascular risk factors (hypertension and generalized obesity) in an apparently healthy population.

MATERIALS AND METHODS

We recruited 898 apparently healthy subjects (318 males and 580 females) of the Igbo ethnic group resident in Enugu (urban), Southeast Nigeria. Data collection was done using the World Health Organization Stepwise approach to Surveillance of risk factors (STEPS) instrument. Subjects had their weight, height, waist and hip circumferences, systolic and diastolic blood pressures measured according to the guidelines in the step 2 of STEPS instrument. Generalized obesity and hypertension were defined using body mass index (BMI) and JNC 7 classifications, respectively. Quantitative and qualitative variables were analyzed using t-test and Chi-square analysis, respectively, while the performance of WC and WHR was compared using the Receiver Operating Characteristic (ROC) analysis. P value was set at <0.05.

RESULTS

The mean age of the subjects was 48.7 (12.9) years. Central obesity was found in 76.9% and 66.5% of subjects using WHR and WC, respectively. WC had a significantly higher area under the curve (AUC) than WHR in all the cardiovascular risk groups, namely, generalized obesity (AUC = 0.88 vs. 0.62), hypertension alone (AUC = 0.60 vs. 0.53), and both generalized obesity and hypertension (AUC = 0.86 vs. 0.57).

CONCLUSION

WC performed better than WHR in predicting the presence of cardiovascular risk factors. Being a simple index, it can easily be measured in routine clinic settings without the need for calculations or use of cumbersome techniques.

Waist circumference values according to height percentiles: a proposal to evaluate abdominal obesity in Mexican children and adolescents between 6 and 16 years of age

BACKGROUND AND AIMS

Waist circumference (WC) is a good anthropometric indicator for diagnosing abdominal obesity across different age groups, including children and adolescents. It is unknown whether height may modify this indicator independent of other variables such as age, gender and ethnicity. We undertook this study to determine whether WC of children and adolescents shows variations in size according to height percentiles and propose these values as reference to assess abdominal obesity in children.

METHODS

We carried out a cross-sectional analytical study in which weight, height and WC were measured in children and adolescents attending elementary schools in Mexico City. Included in the study were 3378 individuals between 6 and 16 years of age. Using quantile regression, estimated values of WC were obtained according to age and gender for the following percentiles of height: 10(th), 25(th), 50(th), 75(th) and 90(th). Likewise, for each of these height percentiles, the following percentiles of WC were calculated: 50(th), 75(th) and 90(th).

RESULTS

Among males, WC values increased 2.0 cm for ten units of height percentiles and 2.5 cm for each year of age. Among females, WC increased 1.0 cm and 2.8 cm, respectively. WC values of individuals of the same age and gender in the lower height percentiles were less than those of individuals in the upper height percentiles.

CONCLUSIONS

WC demonstrates variations directly associated with height percentiles.

Reference curves for BMI, waist circumference and waist-to-height ratio for Azorean adolescents (Portugal)

Objective

There are no percentile curves for BMI, waist circumference (WC) or waist-to-height ratio (WHtR) available for Portuguese children and adolescents. The purpose of the present study was to develop age- and sex-specific BMI, WC and WHtR percentile curves for a representative sample of adolescents living in the Portuguese islands of Azores, one of the poorest regions of Europe, and to compare them with those from other countries.

Design

Cross-sectional school-based study. Weight, height and WC were objectively measured according to standard procedures. Smoothed percentile curves were estimated using Cole's LMS method.

Setting

Azores, Portugal.

Subjects

Proportionate stratified random sample of 1500 adolescents, aged 15–18 years.

Results

Results showed some sex differences in the shape of the BMI curves: in girls, the upper percentile values tend to decrease by the age of 16 and 17 years; whereas in boys, the upper percentiles tend to be flat between 15 and 16 years and then increase until the age of 18 years. In both sexes, the upper percentile values of both WC and WHtR decreased slightly by the age of 16 years and then increased steeply. In both sexes, the Azorean values for the 50th and 90th WC percentiles were higher than those reported for adolescents from the majority of other countries.

Conclusions

The reference curves presented herein provide baseline data for the long-term surveillance of Azorean adolescents, as well as for national and international comparisons.

Effect of recombinant growth hormone on leptin, adiponectin, resistin, interleukin-6, tumor necrosis factor-α and ghrelin levels in growth hormone-deficient children

BACKGROUND

Treatment with GH promotes linear growth and decreases body fat in patients with isolated GH deficiency (GHD). However, few studies have analyzed how GH replacement modifies ghrelin levels and the adipokine profile and the relationship of these modifications with the metabolic changes.

AIMS

To analyze the eventual differences between serum levels of leptin, leptin soluble receptor (sOBR), resistin, adiponectin, interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), total (TG) and acylated ghrelin (AG) and lipid and glycemic profiles in children with GHD, as well as to determine the effect of GH replacement on these parameters during the first year of therapy.

SUBJECTS AND METHODS

Thirty pre-pubertal (Tanner stage I) GHD children and 30 matched controls were enrolled. Children with GHD were studied before and after 6 and 12 months of GH treatment. Weight, height, BMI, fasting glucose, insulin, lipid profile and serum levels of adipokines and ghrelin were studied at every visit. Adi - pokines, insulin and ghrelin levels were determined by using commercial radio- and enzymoimmunoassays.

RESULTS

At baseline children with GHD had significantly higher sOBR (p<0.01) and adiponectin (p<0.01) levels than controls. Treatment with GH resulted in a decline in leptin (p<0.05) and TG (p<0.001) levels, an increase of homeostasis model assessment index and restored IGF-I levels (p<0.001).

CONCLUSIONS

These data indicate that GH replacement has a negative effect on leptin levels and may also produce a slight unfavorable effect on carbohydrate metabolism. In addition, the changes observed in the adipokine profile appear to be independent of body mass index.

Waist circumference and waist for height percentiles in urban South Indian children aged 3-16 years

OBJECTIVES

To develop age and gender specific waist circumference references for urban Indian children aged 3 -16 years.

DESIGN

Cross-sectional study.

SETTING

Urban preschools and schools of Bangalore.

PARTICIPANTS

9060 children (5172 boys and 3888 girls) in the age group of 3-16 years.

METHODS

Weight, height, and waist circumference were measured using standard anthropometric methodology. Percentiles for waist circumference and Waist/height ratio (W/Ht) for each age and gender were constructed and smoothed using the LMS method.

RESULTS

Mean waist circumference increased with age for both girls and boys. The upper end of curve in boys continued to increase, whereas in the girls it tended to plateau at 14 years. The waist circumference of the Indian children from the present study was higher than age and sex matched European children. The proportion of children with W/Ht ratio greater than 0.5 decreased as their age increased.

CONCLUSIONS

These curves represent the first waist and waist height ratio percentiles for Indian children and could be used as reference values for urban Indian children. We suggest that for a start, the 75th percentile of waist circumference from this study be used as an action point for Indian children to identify obesity (as a tautological argument), while retaining the cut-off of 0.5 for the W/Ht ratio; however this underlines the need to derive biologically rational cut-offs that would relate to different levels of risk for adult cardiovascular disease.

Preliminary data on the association between waist circumference and insulin resistance in children without a previous diagnosis

The aim of the present work was to study the association between different anthropometric parameters and insulin resistance (IR) in Spanish schoolchildren without a previous diagnosis. A total of 443 Spanish schoolchildren (9-11 years of age) were studied in this cross-sectional study. The anthropometric measurements collected were weight, height, body circumferences and skinfolds. Body mass index (BMI), waist/hip ratio, percentage body fat and fat-free body mass were determined. Overnight-fasted blood lipids, insulin and glucose levels were analysed, and estimation of IR, taking into account the homeostasis model assessment (HOMA), was calculated. The children with IR had higher serum triglycerides and insulin levels, were heavier and taller, and had a higher BMI, a larger waist circumference, a larger hip circumference, a larger waist/hip ratio and thicker bicipital and tricipital skinfolds than those who did not have IR. Age, sex, BMI and waist circumference explained 32.0% of the variance in the HOMA values; only sex, triglycerides and waist circumference independently influenced this variable. A 1-cm increase in waist circumference was associated with approximately a 3.8% increase in the mean HOMA value. The children with a waist circumference of over the p90 for their age and sex were at greater risk of showing IR as measured by the HOMA: odds ratio = 6.94 (2.01-23.91; P < 0.001). In conclusion, according to these results, waist circumference is the best anthropometric parameter associated with IR in children, and those with a waist circumference of over the p90 for their age and sex would appear to be at particular risk.

Effect of weight loss on high-molecular weight adiponectin in obese children

Our aim was to determine the influence of weight reduction on total (T-) and high-molecular weight (HMW-) adiponectin in obese (OB) prepubertal children. Seventy OB prepubertal white patients were followed for 18 months and studied after reducing their BMI by 1 (n = 51) and 2 standard deviation scores (SDS) (n = 21) under conservative treatment, and 6 months after achieving weight loss (n = 44). Body composition dual-energy X-ray absorptiometry (DXA) and serum levels of T- and HMW-adiponectin, resistin, leptin, leptin soluble receptor (sOB-R), tumoral necrosis factor-α and interleukin-6 were determined. The control group consisted of 61 healthy prepubertal children. At diagnosis T-adiponectin was higher (P < 0.01; confidence interval (+0.04) - (+0.15)) and HMW-adiponectin lower (P < 0.001; confidence interval (-0.45) - (-0.21)) in OB children than in controls. A reduction in body fat increased T- and HMW-adiponectin and sOB-R (all P < 0.001) and decreased leptin (P < 0.001) and interleukin-6 levels (P < 0.05). After 6 months of sustained weight reduction a decrease in tumoral necrosis factor-α (P < 0.01) occurred, whereas weight recovery increased leptin (P < 0.001) and decreased T-adiponectin (P < 0.05). HMW-adiponectin levels negatively correlated with homeostasis model assessment (HOMA) index and BMI in the whole cohort (both P < 0.001), as did T-adiponectin levels and HOMA index in OB patients (P < 0.01), but neither T- nor HMW-adiponectin correlated with body fat content (BFC) in OB children. We conclude that the impairment of T- and HMW-adiponectin levels in childhood obesity is different to that in elder OB patients, showing closer relationship with carbohydrate metabolism parameters than with BFC, but increasing their levels after weight loss and in association with metabolic improvement.

Validity of body mass index and waist circumference to detect excess fat mass in children aged 7-14 years

BACKGROUND/OBJECTIVES

To evaluate the screening performance of body mass index (BMI) and waist circumference (WC) for excess adiposity. In addition, the diagnostic accuracy of cutoffs from different international and national reference systems based on BMI and WC was investigated.

SUBJECTS/METHODS

Data from 2132 Jena children aged 7-14 years conducted in 2005/2006 were analyzed. Receiver operating characteristic (ROC) curves were constructed to assess BMI and WC, as screening measures for excess adiposity (derived from skinfolds). Sensitivity, specificity and positive predictive values (PPVs) were calculated for two BMI-based classification systems (IOTF and German reference) and sample-based WC cutoffs.

RESULTS

The BMI as well as the WC performed well in detecting excess fat mass, indicated by areas under the ROC curve (AUC) close to 1.0, with slightly greater AUCs for BMI than for WC in both sexes. The specificity of all reference systems was high for both sexes (95 to 98%). However, their sensitivities were low (53-67% in boys; 51-67% in girls). PPV were higher for the German reference and the sample-based WC cutoffs than for the IOTF reference, and higher in girls than in boys.

CONCLUSIONS

The setting in which the reference system should be used is important for the selection of the reference system. The results support the use of the BMI-based references for monitoring in epidemiological studies. The sample-based cutoffs for WC should be refined for clinical use on national level.

Waist circumference percentiles for Kuwaiti children and adolescents

OBJECTIVE

Abdominal obesity is a major risk factor for chronic diseases. Yet there are no waist circumference (WC) cut-offs for children in the Arabian Gulf. We developed smoothed WC percentiles for 5-19-year-old Kuwaiti children and adolescents, which could be used in clinical and public health practice. We also examined the percentages of children who had WC ≥ 90th percentile, a value commonly associated with an elevated risk of CVD.

DESIGN

This is a cross-sectional study that was conducted by the Kuwait National Nutrition Surveillance System.

SETTING

Data were collected from representative primary-, intermediate- and secondary-school children as part of the yearly nutrition and health monitoring. Least mean square regression was used to develop smoothed WC curves.

SUBJECTS

A total of 9593 healthy 5.0-18.9-year-old children of both sexes were studied from all areas of Kuwait. Age, gender, residency, education level, weight, height and WC were collected for all participants.

RESULTS

We developed the first smoothed WC curves for Kuwaiti children. Male children had higher WC than female children. WC increased with age in both genders, but larger percentages of male children had WC ≥ 90th percentile. Male children aged >10 years have higher WC percentiles than do female children at the 50th, 75th, 90th and 97th percentiles.

CONCLUSIONS

Male children (especially those aged >10 years) are at higher risk than female children. Few health-care professionals routinely measure WC. WC measurement should be promoted as an important tool in paediatric primary care practice. The use of these age- and gender-specific percentiles can impact public health recommendations for Kuwaiti and other Arab children from the Gulf.

Antropometria como ferramenta de avaliação do estado nutricional coletivo de adolescentes

A antropometria tem sido apontada como o parâmetro mais indicado para avaliar o estado nutricional coletivo. A avaliação nutricional coletiva de adolescentes possui uma dinâmica muito peculiar por se tratar de um momento de intensas mudanças fisiológicas e psicossociais, diretamente associadas à dinâmica nutricional deste grupo. O acompanhamento dessa dinâmica e de suas variáveis intervenientes e interativas é, portanto, um tema de discussão extremamente relevante. Esta revisão tem por objetivo apresentar as aplicações de parâmetros antropométricos à avaliação do estado nutricional de adolescentes. Conclui-se que, enquanto não houver metodologia simples de avaliação da composição corporal, para estudos epidemológicos deve-se manter o uso do índice de massa corporal, associado ou não às variáveis de dobra cutânea e perímetros. Apesar das dificuldades e limitações, as evidências apontam para uma fundamental incorporação das informações sobre a maturação sexual à avaliação do estado nutricional coletivo de adolescentes. Além disso, as investigações devem atentar mais aos parâmetros de definição da população que estará sendo estudada, cuidando, para permitir a comparação entre os estudos.

Utility of waist circumference percentile for risk evaluation in obese children

OBJECTIVE

Increased waist circumference has been shown to contribute to cardiovascular risk in obese adults. This study was designed to examine whether routinely assessing waist circumference in obese children adds predictive value for the development of diabetes and other cardiovascular risk factors.

METHODS

This is a cross-sectional study on a community sample of 188 apparently healthy obese children 7-11 years, 60% black, 39% male. Anthropometry, fasting lipid profile, oral glucose tolerance test, and magnetic resonance imaging of abdominal fat were done. High waist circumference was defined as > or = 90(th) percentile for age and sex. Statistical analyses were done to examine the relationship between waist circumference and the different cardiovascular risk factors.

RESULTS

Those with a high waist circumference had significantly lower high-density lipoprotein, higher triglycerides, fasting insulin, insulin response to glucose, subcutaneous and visceral abdominal fat than those with a normal waist circumference. Children with a high waist circumference were 3.6 times more likely than those with a normal waist status to have a low high-density lipoprotein level, 3.0 times more likely to have high triglycerides, and 3.7 times more likely to have a high fasting insulin level.

CONCLUSIONS

Obese children with waist circumference at or above the 90th percentile are at higher risk for dyslipidemia and insulin resistance than obese children with normal waist circumference. These results indicate that routine waist circumference evaluation in obese children may help clinicians identify which obese children are at greater risk of diabetes and other cardiovascular disease.

Percentile distributions of waist circumference for 7-19-year-old Polish children and adolescents

The aim of the study was to develop waist circumference (WC) percentiles in Polish children and youth and to compare these with the results obtained in other countries. The study comprised a random group of 5663 Polish children aged 7-18 years. Smoothed WC percentile curves were computed using the LMS method. The curves displaying the values of the 50th (WC(50)) and the 90th (WC(90)) percentile were then compared with the results of similar studies carried out in children from the UK, Spain, Germany, Turkey, Cyprus, Canada and the USA. WC increased with age in both boys and girls and in all observed age periods the boys were seen to dominate. For 18-year-old Polish boys and girls the values of WC(90) were 86.5 and 78.2, respectively, and were lower than the current criteria developed by the International Diabetes Federation. Both WC(50) and WC(90) were higher in Polish boys and girls compared with their counterparts in the UK, Turkey and Canada and significantly lower than in children from the USA, Cyprus and Spain. The percentile curves for Polish children and youth, which were developed here for the first time, are base curves that can be applied in analysing trends as well as making comparisons with results of similar studies performed in other countries.

Waist circumference cut-off values for the prediction of cardiovascular risk factors clustering in Chinese school-aged children: a cross-sectional study

BACKGROUND

Waist circumference has been identified as a valuable predictor of cardiovascular risk in children. The development of waist circumference percentiles and cut-offs for various ethnic groups are necessary because of differences in body composition. The purpose of this study was to develop waist circumference percentiles for Chinese children and to explore optimal waist circumference cut-off values for predicting cardiovascular risk factors clustering in this population.

METHODS

Height, weight, and waist circumference were measured in 5529 children (2830 boys and 2699 girls) aged 6-12 years randomly selected from southern and northern China. Blood pressure, fasting triglycerides, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and glucose were obtained in a subsample (n = 1845). Smoothed percentile curves were produced using the LMS method. Receiver-operating characteristic analysis was used to derive the optimal age- and gender-specific waist circumference thresholds for predicting the clustering of cardiovascular risk factors.

RESULTS

Gender-specific waist circumference percentiles were constructed. The waist circumference thresholds were at the 90th and 84th percentiles for Chinese boys and girls respectively, with sensitivity and specificity ranging from 67% to 83%. The odds ratio of a clustering of cardiovascular risk factors among boys and girls with a higher value than cut-off points was 10.349 (95% confidence interval 4.466 to 23.979) and 8.084 (95% confidence interval 3.147 to 20.767) compared with their counterparts.

CONCLUSIONS

Percentile curves for waist circumference of Chinese children are provided. The cut-off point for waist circumference to predict cardiovascular risk factors clustering is at the 90th and 84th percentiles for Chinese boys and girls, respectively.

Serum transaminases concentrations in obese children and adolescents

The aim of the study was to investigate the relationship between liver transaminase levels and metabolic syndrome (MS) features in obese children and adolescents. A total of 132 children and adolescents (73 males and 59 females) aged 8 - 16, participated in the study. All were studied at the department of Paediatrics, University Hospital of Zaragoza (Spain). Inclusion criteria were the existence of obesity as defined by body mass index (BMI) according to Cole cut-off values (when BMI was higher than the age and sex specific equivalent to 30 kg/m2). The definition of metabolic syndrome was according to the International Diabetes Federation criteria. Weight (kg), height (cm), waist circumference (cm), blood pressure and BMI were measured. Laboratory determinations after overnight fasting included: transaminases (ALT, AST, GGT), fasting glucose, insulin, triglycerides and HDL-C. The MS was found in 21.6% of the obese children and adolescents and the prevalence was higher in males (25.9%) than in females (15.9%). Serum transaminases (ALT, AST and GGT) mean concentrations were higher in males than in females, and decreased during pubertal development. The obese children and adolescents with the MS did not show higher transaminases concentrations when compared with those without the MS. Some MS manifestations (mainly waist circumference) showed a correlation with ALT, although all transaminases values were normal according to adult references. Liver transaminases, a surrogate marker of NAFLD, did not show an early and consistent manifestation of abnormalities in the obese children and adolescents studied. In order to define the presence of the disease, it would be necessary to obtain aminotransferase reference standards for children and adolescents, considering pubertal stage and gender.

Components of the Metabolic Syndrome among a Sample of Overweight and Obese Costa Rican Schoolchildren

Background

The term “pediatric metabolic syndrome” includes a cluster of cardiovascular risk factors such as insulin resistance, dyslipidemia (including increased triglycerides and decreased HDL cholesterol), hypertension, and obesity in children. No studies have been performed on this syndrome in a pediatric population in Costa Rica.

Objective

To establish the prevalence of metabolic syndrome and its components in 8- to 10-year old prepuberal overweight and obese schoolchildren.

Methods

This cross-sectional survey was conducted in 214 overweight and obese boys and girls, aged 8 to 10 years, who were selected from six urban schools from San José, Costa Rica. Anthropometric measurements and determinations of blood glucose, insulin, triglycerides, total cholesterol, HDL cholesterol, and high-sensitivity C-reactive protein (hs-CRP) were performed. The home-ostasis model assessment of insulin resistance (HOMA-IR) index and the Castelli index were calculated to assess insulin resistance and cardiovascular risk, respectively. Social and lifestyle variables were obtained through validated questionnaires.

Results

A total of 110 boys and 104 girls participated in this study; 37.9% of them were overweight and 62.1% were obese. Compared with boys, girls were more sedentary and had higher insulin levels (16.05 ± 10.45 μIU/mL vs. 12.72 ± 7.63 μIU/mL, p = .008), body fat (36.5% vs. 30.9%, p < .001), and HOMA-IR indexes (3.5 ± 2.4 vs. 2.8 ± 1.7, p = .014) but lower HDL cholesterol (0.99 ± 0.23 mmol/L vs. 1.08 ± 0.27 mmol/L, p = .009). Obese children had significantly higher mean serum concentrations of insulin, hs-CRP, and triglycerides and higher insulin resistance (estimated by HOMA-IR) than overweight children, but lower mean serum levels of HDL cholesterol. The prevalence of metabolic syndrome in the study population was 5.6%. Other risk factors for developing cardiovascular disease and type 2 diabetes had high prevalence rates among the children: sedentarism (40.6%), family history of type 2 diabetes (73.3%), high LDL cholesterol levels (≥ 2.84 mmol/L) (57.0%), hyperinsulinemia (> 10.5 μIU/mL) (59.8%), insulin resistance (estimated by HOMA-IR ≥ 2.4) (55.1%), and total cholesterol (> 4.39 mmol/L) (60.7%). Children with metabolic syndrome had significantly higher body mass indexes, glucose levels, and triglyceride levels and lower HDL cholesterol levels than children without metabolic syndrome. Insulin had a very strong positive correlation with HOMA-IR values ( r = 0.982), and hs-CRP had a mild positive correlation with body mass index ( r = 0.296) and body fat ( r = 0.320).

Conclusions

This study reported a prevalence of 5.6% of metabolic syndrome among a sample of Costa Rican overweight and obese prepuberal children. Lifestyle interventions focusing on weight reduction and increasing physical activities should be promoted by education and health authorities in order to avoid the early development and onset of type 2 diabetes and atherosclerosis in childhood.

Truncal and abdominal fat as determinants of high triglycerides and low HDL-cholesterol in adolescents

We examined whether abdominal and truncal adiposity, assessed with simple anthropometric indices, determines serum triglycerides and high-density lipoprotein (HDL)-cholesterol levels independently of total adiposity amount in adolescents. A total of 547 Spanish adolescents (284 males and 263 females) aged 13-18.5 years were included in this study. Measures of truncal adiposity included subscapular to triceps ratio, and trunk-to-total skinfolds ratio (TTS%). Waist circumference was used as a surrogate of abdominal adiposity, and BMI was used as a measure of total adiposity. The results of the regression models indicated that levels of triglycerides were positively associated with waist circumference and TTS% after controlling for age and Tanner stage in both sexes. Once BMI was entered in the model, these associations remained significant for waist circumference in females. HDL-cholesterol levels were negatively associated with waist circumference in both sexes, and with subscapular to triceps ratio and TTS% in males, after controlling for age and Tanner stage. Once BMI was entered in the model, these associations remained significant for subscapular to triceps ratio and for TTS% in males. The results of this study suggest that in male adolescents, truncal adiposity is negatively associated with levels of HDL-cholesterol, whereas in females, abdominal adiposity is positively associated with levels of triglycerides independently of total adiposity. These findings highlight the deleterious effect of both truncal and abdominal fat depots on the lipid profile already from the first decades of life.

Nutritional status of an economically-privileged convenience sample of urban children in Guatemala City

BACKGROUND

The worldwide pandemic of overweight and obesity has now reached low-income tropical societies.

OBJECTIVE

To determine whether overweight or obesity is present among children from middle-class Guatemala City homes.

METHODS

A total of 363 children, 173 boys and 190 girls aged 72-131 months, were included for height, weight, and abdominal circumference at its narrowest point (natural waist).

RESULTS

Overall, 58.6% of subjects presented a body mass index within the normal Center for Disease Control and Prevention curve limits, whereas 3.9% fell below this range (low weight), 17.4% were in the risk of overweight range, and 20.1% were classified as overweight. The mean natural waist circumference was 62.6+/-0.9 cm. The waist-circumference-to-height ratio had a median of 0.47, with 36.9% of all children having a waist-circumference-to-height ratio exceeding the proposed 0.5 upper limit.

CONCLUSIONS

Nutrition transition has reached the juvenile population of this Central American republic, at least in its urban, privileged groups.

First reference curves of waist circumference for German children in comparison to international values: the PEP Family Heart Study

BACKGROUND

Waist circumference (WC) is a sensitive marker for abdominal obesity in the pediatric age group. However, WC is influenced by age, sex, ethnicity and body mass index (BMI), causing difficulties in the selection of the most appropriate cut-off value. Considering the lack of reference values in Germany, we developed age- and gender-specific WC smoothed reference curves in German children, and compared them with reference curves obtained from different countries.

METHODS

A representative sample of 3531 German children (1788 boys, 1743 girls) aged 3-11 years participating in the Prevention Education Program (PEP) Family Heart Study was studied. WC was measured according to the recommendations of the World Health Organization, then age- and sex-specific WC reference curves were constructed and smoothed using the LMS method and SPSS 14.0 for statistical analysis.

RESULTS

WC increased with age in both boys and girls. Boys had higher values of WC than girls at every age and percentile level. 4.1% of the boys and 2.8% of the girls had WC values >97th percentile as compared to 6.3% of the boys and 4.9% of the girls with >97th percentile of BMI (severe obesity). 3.1% of the boys and 2% of the girls had both risk factors. Because 85.3% of the boys and 87.3% of the girls with WC<90th percentile had normal weight, this cut-off point might be appropriate for defining high WC.

CONCLUSIONS

These first WC reference curves of German children can be added to the existing international curves for children; comparison of different populations demonstrated that the German values are in the middle range of the curves obtained in different countries. Our findings about significant differences between the reference curves obtained in various regions emphasize the necessity of developing population-specific percentiles, and to use them in clinical and epidemiological studies among children.