Waist circumference and body mass index in Chinese children: cutoff values for predicting cardiovascular risk factors

Comparison of Glycosylated Haemoglobin, Blood Pressure, and Anthropometric Measurements Depending on Gender and Bodyweight State in Adolescents

Background/Objective: The greatest anthropometric and physiological changes occur during adolescence. Assessment of growth patterns is necessary to prevent future health risks. Aims: To describe the values of glycosylated haemoglobin (HbA1c), systolic (SBP) and diastolic (DBP) blood pressure, triceps skinfold, and abdominal circumference according to gender and age (between 12 and 17 years), as well as explore the differences between body weight conditions. Methods: A descriptive cross-sectional study was carried out, including 4130 adolescents between 12 and 17 years old. SBP and DBP, HbA1c, triceps skinfold, and abdominal circumference were evaluated. Results: Significant differences were observed between males and females for HbA1c (p < 0.001), SBP (p < 0.001), triceps curl (p < 0.001), and abdominal circumference (p < 0.001), independently of the age group. Regardless of gender and age groups, significant differences were observed between overweight/obese and normal-weight adolescents in SBP (p < 0.001), DBP (p < 0.001 to 0.009), triceps skinfold (p < 0.001), and abdominal perimeter (p < 0.001). Conclusions: Our findings revealed higher SBP, DBP, triceps skinfold, and abdominal circumference in overweight/obese adolescents compared to normal-weight adolescents in both genders.

Relationship between waist circumference and cardiorespiratory fitness in Chinese children and adolescents: Results from a cross-sectional survey

Background

This article assessed the relationship between waist circumference (WC) and cardiorespiratory fitness (CRF) of children and adolescents aged 7–18 years.

Methods

Using a stratified cluster random sampling method, 92,574 children and adolescents (47,364 males and 45,210 females) were extracted. CRF was measured by performance in the 20 m shuttle run test (20mSRT) and the subsequent estimation of maximal oxygen consumption (V˙O_2max) using the Léger equations. Participants were divided into five groups of WC percentiles and three groups of CRF percentiles by the Lambda Mu Sigma (LMS). The correlation between WC and CRF was examined by one-way ANOVA and curvilinear regression analysis.

Results

WC increased with age, while V˙O_2max showed an age-related decline. Controlling for gender, urban, and rural factors, for children and adolescents aged 10–12, 13–15, and 16–18 years, the V˙O_2max Z-score of the normal WC group was significantly higher than the very low WC group (P < 0.05). Controlling for gender, urban, and rural factors, for participants aged 7–18 years, the V˙O_2max Z-score of the normal WC group was significantly higher than the high WC group and the very high WC group (P < 0.05).

Conclusions

It generally shows a “parabolic” trend between WC-Z and V˙O_2max-Z. The CRF among children and adolescents in the normal WC group is significantly higher than that in the low and the high WC groups.

Body adiposity measures and risk of adolescent hypertension among the postpubescents Northeast India

OBJECTIVES

The present study attempts to associate and predict adolescent hypertension in Northeast India through body adiposity measures.

METHOD

A total of 728 adolescents aged 15 years and above were included in the present study after consent. Blood pressure and related anthropometric data were collected. The prevalence rate was calculated. Significant tests and correlation analyses were conducted between the blood pressure parameters and anthropometric body adiposity measures. The odds ratio (OR) was also calculated to assess the likelihood of risks. The receiver operating characteristic (ROC) curve analysis was performed to find the measured parameters' predictive cut-off values.

RESULTS

The prevalence of adolescent hypertension is 29.12%, and elevated blood pressure is 20.47%. Boys are more hypertensive than girls. Obese adolescents are more prone to hypertension. Overweight, obese, and abdominal volume index (AVI) has 2.31, 5.15, and 3.41 OR to develop hypertension significantly, irrespective of gender. Among the boys, waist circumference (WC), AVI, and waist to height ratio (WHtR) significantly correlate with hypertension at adjusted for age; they are better predictors with area under curve (AUC) value reach 0.7. Among the females, the BMI reaches AUC 0.7, making it a better assessment for hypertension.

CONCLUSION

The study highlights the concerns of adolescent hypertension among Northeast Indian adolescents, which needs attention. More studies in different regions must be conducted to understand the problem's crux to enable health policymakers to promote adolescent health.

Associations of caesarean section with body mass and waist circumference trajectories from age 2 to 13 years: A nationally representative birth cohort study in Australia

BACKGROUND

Measuring obesity at a single time point does not explain the independent association between C-section birth and obesity in a child's life course.

OBJECTIVES

This study aimed to explore the longitudinal link between C-section with obesity trajectories during childhood.

METHODS

We analysed data from a nationally representative birth cohort study named "Longitudinal Study of Australian Children (LSAC)", commenced in 2004. General obesity was measured through the Body Mass Index (BMI) and abdominal obesity by the Waist Circumference (WC) using the biennially collected data from age 2 to 13 years (2006-2016). Group-based trajectory modelling was applied to identify the distinct pattern of BMI & WC trajectories. Multivariable multinomial logistic regression models were used to assess the association between C-section and obesity trajectories after adjusting for perinatal factors.

RESULTS

Of the 3524 study children, 30% were born by C-section. Three distinct BMI trajectory groups emerged: stable normal (60%), moderately rising (33%) and accelerated (7%). The WC trajectories were, stable normal (58%), moderate (34%) and accelerated (8%). Compared with the stable normal group, children born through C-section had a higher risk to follow accelerated trajectories for both BMI (OR:1.72; 95% CI: 1.28-2.32) and WC (OR: 1.51; 95% CI: 1.15-1.98) with P-value <0.01. Adjustment of potential confounders did not alter these associations substantially.

CONCLUSIONS

C-section birth significantly increases the risk of having an accelerated obesity trajectory in children. Limiting the C-section for absolute clinical causes and early institution of preventive approach can reduce the obesity burden among children delivered through C-section.

LMX1B rs10733682 Polymorphism Interacts with Macronutrients, Dietary Patterns on the Risk of Obesity in Han Chinese Girls

Previous studies have found that LMX1B rs10733682 polymorphism is associated with Body Mass Index (BMI) in European and American Indian adults. In this study, the association of rs10733682 polymorphism with obesity-related indicators, and its interaction with macronutrients and dietary patterns (DPs) were explored in Chinese children (n = 798). The rs10733682 polymorphism was genotyped by improved Multiple Ligase Detection Reaction (iMLDR). Four DPs were identified by factor analysis. The AA genotype had a higher incidence of overweight/obesity than GG+GA genotypes (P = 0.010) in girls (n = 398), but no difference in boys. The AA genotype in girls could interact with intake of energy, fat and carbohydrate, causing an increased triglyceride (TG), (P = 0.021, 0.003, 0.002, respectively), and also could interact with energy from protein, causing an elevated BMI (P = 0.023) and waist (P = 0.019). Girls inclining to the HED (high-energy density)-DP were associated with increased TG (P = 0.033), and girls inclining to the VEF (vegetables, eggs, and fishes based)-DP were associated with decreased total cholesterol (TC, P = 0.045) and decreased low density lipoprotein cholesterin (LDL, P = 0.016). The findings indicated that the AA genotype of rs10733682 and the HED-DP are potential risk factors of obesity in Chinese girls.

Interaction of the CMTM7 rs347134 Polymorphism with Dietary Patterns and the Risk of Obesity in Han Chinese Male Children

A genome-wide association study (GWAS) in the Han Chinese population had found that single nucleotide polymorphism (SNP) on the CMTM7 gene rs347134 was significantly associated with Body Mass Index (BMI). In the present study, the association of the rs347134 SNP with obesity and its interaction with dietary patterns (DPs) were explored in Han Chinese children. This cross-sectional study group included 1292 children, in whom obesity-related indicators were evaluated, the rs347134 SNP was genotyped by improved Multiple Ligase Detection Reaction (iMLDR), and the DPs were identified by principal component factor analysis. The GG genotype exhibited higher odds of general overweight/obesity (P = 0.038) and central obesity (P = 0.039) than AA + GA genotypes in boys. Four DPs of boys were identified: healthy balanced (HBDP), nuts and sweets-based (NSDP), animal food-based (AFDP), and wheaten and dairy-based (WDDP). Boys with the GG genotype were significantly more inclined to AFDP (P = 0.028) and had a shorter sleep duration (P = 0.031). Significant interactions were observed; boys with the GG genotype displayed a higher LDL in AFDP (P = 0.031) and higher FBG in NSDP (P = 0.038), respectively. Our findings indicate for the first time that the GG genotype of CMTM7 rs347134 is potentially a novel obesity risk factor for Han Chinese male children and is associated with dietary patterns more or less.

Changes in dietary habits and prevalence of cardiovascular risk factors among school students in Macao, China

OBJECTIVE

Given the increasing burden of childhood obesity, it is important to examine the changes in dietary habits and prevalence of cardiovascular risk factors among Macao students.

METHODS

A cross-sectional study was conducted among primary and secondary school students in Macao, China in 2014-2015 with addition to data collected from 2008 to 2009 for comparison. The dietary behaviours, prevalence of obesity and dyslipidaemia were compared by study period.

SUBJECTS

In 2014-2015, dietary assessment was conducted among 3635 students, physical assessment was conducted among 1427 school students. In 2008-2009, dietary assessment was conducted among 4271 students, physical assessment was conducted among 1700 school students.

RESULTS

When compared with students in 2008, higher percentage of students from present study period consumed dairy products, crispy food and chocolate, while fewer students had fruits, vegetables and fried food at least once every day. Despite lower prevalence of elevated total cholesterol and low-density-lipoprotein cholesterol, the rate of general obesity, low high-density-lipoprotein cholesterol and hyperglycaemia has increased significantly in 2014-2015. Students aged 12-14 consumed less fruits and vegetables and suffered from higher rate of general and abdominal obesity, as well as low high-density-lipoprotein cholesterol and elevated serum triglycerides in 2014-15.

CONCLUSIONS

The students' diet had both favourable and unfavourable changes. The rate of obesity and dyslipidaemia rises, while the situation for students aged 12-14 is more concerning.

Central obesity and hypertension among rural adults of Paschim Medinipur, West Bengal, India

Obesity is generally classified into generalized obesity (BMI ≥30 kg/m2) and abdominal or central obesity (WC ≥90 cm for men and WC ≥80 cm for women) based on World Health Organization recommendation for Asians. Hypertension is one of the most common obesity-related complications, and about 30% of hypertensive individuals can be classified as being obese. The present study aimed to investigate the effect of different age groups (years) on the anthropometric and derived variables. It determined the correlation between anthropometric and derived variables and also estimated the frequency of central obesity and hypertension. Finally, it investigated the relationship between central obesity and blood pressure among rural Bengalee adults of Dirghagram village of Ghatal Block, Paschim Medinipur, West Bengal, India. The present cross-sectional study was undertaken among 310 rural adults (154 males; 156 females) aged over 18 years. Our study was carried out during March, 2017. Height (cm), weight (kg), waist circumference (cm), hip circumference (cm) and blood pressure (systolic and diastolic) were measured using standard procedures. One way ANOVA analysis on most of the anthropometric and derived variables showed a statistically significant increase from younger to older age group in both sexes (p<0.001;p<0.01; p<0.05). In addition to that, more females had central obesity using waist circumference (55.8% vs. 19.5%), waist hip ratio (87.2% vs. 35.7%), waist height ratio (73.7% vs. 44.2%), and conicity index (87.2% vs. 57.8%) criteria, and hypertension (52.5% vs. 27.3%). The prevalence of central obesity was much higher in case of hypertensive individuals. Therefore, the present study showed a high prevalence of central obesity among the rural adults of Dirghagram village. Furthermore, central obesity contributed in increasing hypertension among the villagers.

Associations between Sleep Pattern and Quality and Cardiovascular Risk Factors among Macao School Students

Background: Despite accumulating evidence showing that sleep duration and cardiometabolic health are correlated, the association of sleep regularity and quality with cardiovascular risk factors in children and adolescents remains inconclusive. Therefore, we examined the relationship between sleep regularity/quality and cardiovascular risk factors in children and adolescents in Macao, China. Methods: We conducted a cross-sectional study among primary and secondary school students (age range: 9-18 years) in Macao, China. Body weight, height, waist circumference (WC), and serum lipid levels were measured. Sleep regularity and sleep quality were assessed by using the Pittsburgh Sleep Quality Index. Multivariable logistic regression was conducted to examine the relationship of sleep variables with the increased likelihood of body mass index (BMI)-classified overweight/obesity, WC-classified obesity, and dyslipidemia. Results: A total of 1078 school students were included in the analysis. Differences of >2 hours between weekday and weekend bedtimes were associated with the increased risk of BMI-classified overweight/obesity (odds ratio = 2.58, 95% confidence interval = 1.55-4.31, p < 0.01) after being adjusted for sleep variables and lifestyle factors. No statistically significant association was found between poor sleep quality and any other outcome. Conclusions: Irregular bedtime was associated with elevated body weight regardless of sleep amount and quality. Thus, regular bedtimes are recommended as a simple but practical strategy for preventing obesity.

Serum Chemerin Levels Correlate With Determinants of Metabolic Syndrome in Obese Children and Adolescents

Objectives

This study aimed to investigate serum chemerin concentrations in obese children and adolescents and to investigate the associations of chemerin with body mass index (BMI), lipid levels, and insulin sensitivity.

Methods

Forty-eight obese and 40 nonobese Chinese children and adolescents were included in the study. BMI and levels of chemerin, lipids, glucose, and insulin were measured following an overnight fast. The Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) and BMI standard deviation score (BMI-SDS) were determined for all participants.

Results

Serum chemerin levels were found to be significantly higher in obese children and adolescents than in control group members (94.83 ± 5.99 ng/mL vs 56.43 ± 4.16 ng/mL, P < .001). There were significant correlations between chemerin and age, BMI, BMI-SDS, total triglyceride (TG) levels, insulin levels, and HOMA-IR. After controlling for age, we found that chemerin levels were also significantly correlated with BMI-SDS (r =+ 0.284, P = .008) and HOMA-IR (r =+ 0.241, P = .034). In a stepwise multiple regression analysis, we observed only BMI-SDS to be an important determinant of chemerin level.

Conclusions

In our sample of Chinese children and adolescents, chemerin levels were significantly higher in the obese group than in the control group. Chemerin levels were positively correlated with BMI-SDS and HOMA-IR and negatively correlated with age. We thus believe that further study is necessary to investigate the risk of metabolic abnormalities in young obese children and adolescents.

Association between Changes in Anthropometric Indices and in Fasting Insulin Levels among Healthy Korean Adolescents: The JS High School Study

BACKGROUND

This study investigated the association between changes in anthropometric indices and fasting insulin levels among healthy adolescents and whether the association differed by baseline obesity status.

METHODS

This analysis was based on data collected for the JS High School study; 884 healthy adolescents aged 15 to 16 years followed up for 24 to 30 months were included. Changes in anthropometric indices and fasting insulin levels were computed as the difference between baseline and follow-up values. Multivariate linear regression models were used to determine the association between changes in anthropometric indices and fasting insulin levels. Based on body mass index (BMI)-for-age and waist circumference (WC)-for-age percentiles, participants were classified as normal weight (<85th percentile), overweight (85th percentile to <95th percentile), or obese (≥95th percentile).

RESULTS

Changes in BMI, WC, waist-hip ratio, and waist-height ratio were significantly associated with changes in fasting insulin levels in both sexes (P<0.05). In analyses stratified by baseline obesity status, the association between change in BMI and change in fasting insulin was significantly stronger in overweight (males: standardized β=1.136; females: standardized β=1.262) and obese (males: standardized β=1.817; females: standardized β=2.290) participants than in those with normal weight (males: standardized β=0.957; females: standardized β=0.976) at baseline. Results were similar for changes in WC.

CONCLUSION

Changes in anthropometric indices were positively associated with fasting insulin level increases. Moreover, those who were overweight or obese at baseline had a higher absolute increase in fasting insulin levels per one standard deviation unit increase in anthropometric indices than adolescents with normal weight.

Feasibility of anthropometric indices to identify dyslipidemia among adults in Jilin Province: a cross-sectional study

Background

Dyslipidemia and other cardiovascular disease (CVD) risk factors have a strong association with obesity. Anthropometric indices have been widely used to evaluate obesity in clinical and epidemiological studies. We aim to investigate association between serum lipid levels and different anthropometric indices.

Methods

Our study included 17,554 participants. We mainly investigated area under the receiver operating characteristic (AUROC) curves and optimal operating points (OOPs) between the anthropometric indices and serum lipid levels or categories of abnormal serum lipid indices.

Results

For predicting one/two categories of abnormal serum lipid indices among the anthropometric indices, AUROC value of WC was the highest in men (0.718), and AUROC values of BRI and WHtR were the highest in women (0.700 and 0.700) (all P < 0.001); OOP of WC was 82.450 in men; OOPs of BRI and WHtR were 3.435 and 0.504 in women. For predicting three/more categories of abnormal serum lipid indices among the anthropometric indices, AUROC value of WC was the highest in men (0.806), and AUROC values of BRI and WHtR were the highest in women (0.783 and 0.783) (all P < 0.001); OOP of WC was 84.150 in men; OOPs of BRI and WHtR were 3.926 and 0.529 in women.

Conclusions

WC was a good predictor for one/two or three/more categories of abnormal serum lipid indices in men. However, BRI and WHtR were good predictors for one/two or three/more categories of abnormal serum lipid indices in women. ABSI showed the weakest predictive power.

Electronic supplementary material

The online version of this article (10.1186/s12944-017-0648-6) contains supplementary material, which is available to authorized users.

Pubertal Stage, Body Mass Index, and Cardiometabolic Risk in Children and Adolescents in Bogotá, Colombia: The Cross-Sectional Fuprecol Study

This study explored the association between pubertal stage and anthropometric and cardiometabolic risk factors in youth. A cross-sectional study was conducted in 2877 Colombian children and adolescents (9–17.9 years of age). Weight, height, and waist circumference were measured and body mass index (BMI) was calculated. A biochemical study was performed to determine the cardiometabolic risk index (CMRI). Blood pressure was evaluated and pubertal stage was assessed with the Tanner criteria. Hierarchical multiple regression analyses were performed. The most significant variable (p < 0.05) in the prognosis of cardiometabolic risk was found to be the BMI in both boys and girls. In the case of girls, the pubertal stage was also a CMRI predictive factor. In conclusion, BMI was an important indicator of cardiovascular risk in both sexes. Pubertal stage was associated with cardiovascular risk only in the girls.

Intervención integral de ocho meses disminuye el peso y mejora los niveles de depresión y ansiedad en obesos severos y mórbidos

Introducción. La obesidad mórbida genera una disminución considerable de la expectativa y calidad de vida, según lo cual existen niveles aumentados de depresión y ansiedad.Objetivo. Determinar los efectos de un programa de tratamiento integral en la pérdida de peso y los niveles de ansiedad y depresión de obesos severos y mórbidos.Materiales y métodos. Se estudiaron 4 hombres y 12 mujeres de un promedio de 34 26 años, candidatos a cirugía bariátrica. 6 obesos severos y 10 pacientes con obesidad mórbida participaron en una intervención de tratamiento integral de 8 meses. Se evaluaron en preintervención y post intervención: peso, índice de masa corporal (IMC), contorno de la cintura, capacidad cardiorrespiratoria, ansiedad y depresión.Resultados. El peso y el IMC posterior a la intervención disminuyeron de forma significativa (p<0.001) en un 12.28% y 12.30%, respectivamente, el contorno cintura presentó una disminución de un 11.67% (p< 0.001). Además, la capacidad respiratoria mejoró bastante (p<0.001). Los síntomas ansiosos y depresivos disminuyeron de manera significativa (p<0.001).Conclusión. La intervención integral de 8 meses presenta beneficios significativos en la pérdida de peso de los participantes y en la mejora de los niveles de ansiedad y depresión. Por tal motivo, la intervención realizada puede recomendarse para el tratamiento de esta condición.

Relationship between body fat percentage determined by bioelectrical impedance analysis and metabolic risk factors in Syrian male adolescents (18–19 years)

The association between increasing obesity and metabolic syndrome among adolescent and the adverse consequences in adulthood including type-2 diabetes and coronary heart disease is well documented. The main objectives of this study were to evaluate the major metabolic risk factors and some clinical important parameters in Syrian male adolescents (18–19 years old), and to assess the correlations between BF% determined by BIA-man prediction equation and metabolic risk factors in the same group. The correlations between body fat percentage (BF%) based on BIA-man predictive equations, blood pressure, fasting blood sugar (FBS), cholesterol (Chol), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), triglycerides (TG), Hematocrit (Ht), and hemoglobin (Hb) in 1596 healthy Syrian adolescents aged 18-19 years and the mean values of these parameters were examined. Data showed that, DBP, Chol, TG, LDL and TG/HDL-C were significantly (p<0.05) higher in overweight and obese subjects in compression to normal weight cases. Whereas, SBP, FBS and Ht were significantly (p<0.05) higher in obese subjects in compression to normal weight. However, all measured variable related to metabolic syndrome risk factors increased with increasing the BF% determined by BIA-man. The present study suggests that % BF by BIA-man is a good predictor of metabolic risks factors for Syrian adolescents.

Usefulness of the Waist Circumference-to-Height Ratio in Screening for Obesity and Metabolic Syndrome among Korean Children and Adolescents: Korea National Health and Nutrition Examination Survey, 2010-2014

The aims of this study were to assess the diagnostic value of the weight-to-height ratio (WHtR) for the detection of obesity and metabolic syndrome (MS) in Korean children and adolescents, and to determine the advantages of WHtR as a population-based screening tool in comparison with other obesity indicators, such as body mass index (BMI) and waist circumference (WC). We performed a cross-sectional analysis of data from 3057 children and adolescents (1625 boys, 1332 girls) aged 10-19 years who were included in the fifth Korean National Health and Nutrition Examination Survey (KNHANES, 2010-2012) up to the second year of the sixth KNHANES (2013-2014). Receiver operation characteristic (ROC) curves were generated to determine the optimal cutoff value and accuracy of WHtR for predicting individual obesity indicators or more than two non-WC components of MS. The area under the ROC curve (AUC) is a measure of the diagnostic power of a test. A perfect test will have an AUC of 1.0, and an AUC equal to 0.5 means that the test performs no better than chance. The optimal WHtR cutoff for the evaluation of general obesity and central obesity was 0.50 in boys and 0.47-0.48 in girls, and the AUC was 0.9. Regarding the assessment of each MS risk factor, the optimal WHtR cutoff was 0.43-0.50 in boys and 0.43-0.49 in girls, and these cutoffs were statistically significant only for the detection of high triglyceride and low High-density lipoprotein (HDL) cholesterol levels. When a pairwise comparison of the AUCs was conducted between WHtR and BMI/WC percentiles to quantify the differences in power for MS screening, the WHtR AUC values (boys, 0.691; girls, 0.684) were higher than those of other indices; however, these differences were not statistically significant (boys, p = 0.467; girls, p = 0.51). The WHtR cutoff value was 0.44 (sensitivity, 67.7%; specificity, 64.6%) for boys and 0.43 (sensitivity, 66.4%; specificity, 66.9%) for girls. There was no significant difference between the diagnostic power of WHtR and that of BMI/WC when screening for MS. Although the use of WHtR was not superior, WHtR is still useful as a screening tool for metabolic problems related to obesity because of its convenience.

Identifying Children at Risk of High Myopia Using Population Centile Curves of Refraction

Purpose

To construct reference centile curves of refraction based on population-based data as an age-specific severity scale to evaluate their efficacy as a tool for identifying children at risk of developing high myopia in a longitudinal study.

Methods

Data of 4218 children aged 5–15 years from the Guangzhou Refractive Error Study in Children (RESC) study, and 354 first-born twins from the Guangzhou Twin Eye Study (GTES) with annual visit were included in the analysis. Reference centile curves for refraction were constructed using a quantile regression model based on the cycloplegic refraction data from the RESC. The risk of developing high myopia (spherical equivalent ≤ -6 diopters [D]) was evaluated as a diagnostic test using the twin follow-up data.

Results

The centile curves suggested that the 3^rd, 5^th, and 10^th percentile decreased from -0.25 D, 0.00 D and 0.25 D in 5 year-olds to -6.00 D, -5.65D and -4.63 D in 15 year-olds in the population-based data from RESC. In the GTES cohort, the 5^th centile showed the most effective diagnostic value with a sensitivity of 92.9%, a specificity of 97.9% and a positive predictive value (PPV) of 65.0% in predicting high myopia onset (≤-6.00D) before the age of 15 years. The PPV was highest (87.5%) in 3^rd centile but with only 50.0% sensitivity. The Mathew’s correlation coefficient of 5^th centile in predicting myopia of -6.0D/-5.0D/-4.0D by age of 15 was 0.77/0.51/0.30 respectively.

Conclusions

Reference centile curves provide an age-specific estimation on a severity scale of refractive error in school-aged children. Children located under lower percentiles at young age were more likely to have high myopia at 15 years or probably in adulthood.

Parental Body Mass Index Is Associated With Adolescent Obesity in Taiwan

Adolescent obesity is a crucial public health concern, and understanding its risk factors can facilitate the establishment of prevention policies. In this study we investigated the prevalence of adolescent obesity in Taiwan, determined the influential factors, and compared the prevalence of obesity in our study population with international indices. The cross-sectional study was an analysis of data from the 2010-2011 Nutrition and Health Survey in Taiwan, an anthropometric measurement and questionnaire survey of adolescents aged 11-18 years. Our sample was 1,826 adolescents (910 males and 916 females). Data were analyzed using logistic regression modeling. Based on body mass index standards specific to Taiwan norms, the prevalence of overweight and obesity in Taiwan adolescents was 12.4% and 16.8%, respectively. The prevalence was lower when international indices of overweight and obesity were applied. In logistic regression, obesity was linked to male gender, an obese father, overweight or obese mother, poor dietary attitudes, and perceived low dietary benefits. Monitoring and preventing adolescent obesity should focus on both adolescents and their parents. When planning behavioral change and education for adolescent obesity, health professionals and policy-makers should view the family as a unit. © 2016 Wiley Periodicals, Inc.

BMI, Waist Circumference Reference Values for Chinese School-Aged Children and Adolescents

Background: Childhood obesity has become one of the most serious public health challenges in the 21st century in most developing countries. The percentile curve tool is useful for monitoring and screening obesity at population level, however, in China, no official recommendations on childhood body mass index (BMI) and waist circumference (WC) reference percentiles have been made in practice. Aims: to construct the percentile reference values for BMI and WC, and then to calculate the prevalence of overall and abdominal obesity for Chinese children and adolescents. Methods: A total of 5062 anthropometric records for children and adolescents aged from 7 to 18 years (2679 boys and 2383 girls) were included for analysis. The participants were recruited as part of the national representative “China Health and Nutrition Survey” (CHNS). Age, gender, weight, height, and WC were assessed. Smoothed BMI and WC percentile curves and values for the 3rd, 5th, 10th, 15th, 25th, 50th, 75th, 85th, 90th, 95th and 97th percentiles were constructed by using the Lambda-Mu-Sigma (LMS) method. The prevalence estimates of the overall and abdominal obesity were calculated by using the cut-offs from our CHNS study and the previous “Chinese National Survey on Students’ Constitution and Health” (CNSSCH) study, respectively. The difference between prevalence estimates was tested by a McNemar test, and the agreement between these prevalence estimates was calculated by using the Cohen’s kappa coefficient. Results: The prevalence values of overall obesity based on the cut-offs from CHNS and CNSSCH studies were at an almost perfect agreement level in boys (κ = 0.93). However, among girls, the overall obesity prevalence differed between the studies (p < 0.001) and the agreement was weaker (κ = 0.76). The abdominal obesity prevalence estimates were significant different according to the two systems both in boys and girls, although the agreement reached to 0.88, which represented an almost perfect agreement level. Conclusions: This study provided new BMI and WC percentile curves and reference values for Chinese children and adolescents aged 7–18 years, which can be adopted in future researches. Large longitudinal study is still needed to reveal the childhood growth pattern and validate the inconsistence between different percentile studies.

Gender and urban-rural difference in anthropometric indices predicting dyslipidemia in Chinese primary school children: a cross-sectional study

BACKGROUND

Childhood dyslipidemia is a critical factor of lifelong health. Therefore, screening and controlling dyslipidemia from childhood is a practical healthy strategy. However, few studies have examined the performance of anthropometric predictors of dyslipidemia in Chinese children, let alone the potential gender and urban-rural disparity. Thus, we evaluated anthropometric indices predicting dyslipidemia by genders and living areas in Chinese children.

METHODS

Data were from a health and nutrition survey conducted in seven urban areas and two rural areas in China between 2011 and 2012. The serum lipid levels of the participants were compared between genders and living areas. The body mass index z-score (BMI z-score), waist-hip ratio (WHR), waist-height ratio (WHtR), and mid-upper arm height ratio (MaHtR) were used as predictors. The receiver operating characteristic (ROC) analysis was performed to investigate the ability of anthropometric indices predicting dyslipidemia.

RESULTS

A total of 773 participants (average age = 9.3 ± 1.7 y) were included. The prevalence of dyslipidemia was 10.9%. Anthropometric indices were all significantly related to blood lipid profiles in boys after adjustment for age. The areas under the ROC curves (ACUs) were significantly larger than 0.5 in boys (ranged between 0.66-0.73), and were larger in rural boys (ranged between 0.68 and 0.94). MaHtR and WHR were associated with the highest specificity (93.8%) and highest sensitivity (100%), respectively.

CONCLUSION

Using anthropometric indices, screening for dyslipidemia may be more appropriate in boys than in girls in China, especially in rural boys. The BMI z-score, WHR, WHtR, and MaHtR were all significantly associated with dyslipidemia in boys; using WHR and MaHtR as indicators achieved the highest sensitivity and specificity, respectively.

Association between waist circumference and childhood-masked hypertension: A community-based study

AIM

The aim of this study is to determine the association between waist circumference (WC) and childhood-masked hypertension.

METHODS

A territory-wide, school-based cohort of 1385 Hong Kong students (672 boys and 713 girls) aged 8-17 years was analysed. The ambulatory blood pressure-monitoring assessment was performed using validated oscillometric recorders (A&D TM-2430 (A&D Inc., Tokyo, Japan)) following American Heart Association's recommendations. Subjects were considered normotensive if their casual blood pressure, 24-h daytime and night-time average systolic blood pressure and diastolic blood pressure (DBP) were <95th percentile. If one or more of the ambulatory blood pressure parameters was ≥95th percentile, subjects would be considered suffering from masked hypertension (MH). Subjects who had three successive casual blood pressure measurements above the 95th percentile were excluded.

RESULTS

By body mass index, 148 (10.7%) subjects were obese, 182 (13.1%) overweight and 359 (25.9%) having larger WC (≥85th percentiles). MH was diagnosed in 217 subjects (15.7%). Subjects with larger WC or obesity were significantly associated with higher 24-h daytime and night-time systolic blood pressure (≥95th percentile) (odds ratios from 1.84 to 2.09 and from 2.07 to 3.54 for larger WC and obese respectively, all P < 0.05) as well as 24-h DBP for larger WC (odds ratio = 2, P = 0.015) than normal subjects adjusted by sex, age and height.

CONCLUSION

Waist circumference and body mass index are independent risk factors of childhood and adolescent MH. WC appears a significant associated factor of elevated 24-h DBP in children aged 8-17 years.

Risk factors for erectile dysfunction in patients with cardiovascular disease

Objective

To examine the relationship between risk factors for cardiac disease and erectile dysfunction (ED) in men from Xi’an, China.

Methods

Participants were patients with cardiovascular disease who visited the Cardiovascular Medicine Department of Xi’an Jiaotong University First Affiliated Hospital between September 2011 and March 2012. Two hundred and fifty patients were issued with questionnaires and underwent a physical examination and blood test.Risk factors for ED were identified using univariate and multivariate analyses.

Results

In total, 222 participants returned valid questionnaires (89% response rate), underwent a physical examination and blood test, and were included in the study. The most common cardiovascular diseases were hypertension (n = 142; 64%), coronary heart disease (n = 90; 41%) and angina pectoris (n = 78; 35%). Most patients (n = 144; 65%) had two or more cardiovascular diseases. Age, smoking, body mass index, total cholesterol level, hypertension and the ratio of total cholesterol to high-density lipoprotein cholesterol were significantly associated with ED. Domestic location, level of education, participation in physical activity, diabetes and drinking alcohol were not associated with ED.

Conclusions

Common risk factors for cardiovascular disease are associated with ED in patients with cardiovascular disease. This study furthers understanding of the risk factors for ED in Chinese patients with cardiovascular disease and paves the way for further research into the prevention of ED.

Waist-to-height ratio as a measure of abdominal obesity in southern Chinese and European children and adolescents

BACKGROUND

Waist-to-height ratio (WHtR), with a 0.5 threshold (WHtR0.5), is regarded as a simple age- and gender-independent criterion of abdominal obesity (AO) and a better predictor than the 90th percentile of waist circumference (WCP90).

OBJECTIVE

An analysis of gender and ethnic differences of WHtR and other AO indices between children and adolescents from southern China (HK: Hong-Kong, China) and Europe (LD: Łódź, Poland).

SUBJECTS

Two large cross-sectional surveys of children and adolescents aged 7-19 years, one from LD (13 172) and one from HK (14 566).

METHODS

The percentile and standardized values of WHtR and other parameters (WC, body mass index (BMI)) were assessed using the LMS method. The WHtR values corresponding to WCP90 and to the BMI definition of global obesity (BMIP95) were evaluated with the polynomial regression model. The compliance of the AO prevalence data, obtained with two criteria (WCP90 vs WHtR0.5) was analyzed using Cohen's kappa index (κC).

RESULTS

The WHtR data of Polish subjects were generally higher than those of their HK peers, and the ethic differences increased with age. The WHtR values of HK boys showed a stronger relationship with BMI z-score. WHtR corresponding to WCP90 assumed values <0.5. An application of Cohen's kappa coefficient (κC) to Polish subjects showed either 'substantial' (κC>0.6) or 'almost perfect' (κC>0.8) agreement in the AO prevalence for both criteria (WCP90 and WHtR0.5). For these criteria, either 'fair' (κC <0.4) or 'moderate' (κC<0.6) AO consistency ratings were observed among HK girls. In HK boys, a significant difference in the prevalence of AO was observed, independent of the criterion used.

CONCLUSIONS

Our results provide further evidence of the need for developing ethnic-specific WC charts and for recommending that a WHtR cutoff of 0.5 may not be appropriate to predict cardiometabolic risk in children of different ethnic groups.

Associations of pubertal stage and body mass index with cardiometabolic risk in Hong Kong Chinese children: A cross-sectional study

BACKGROUND

Puberty is associated with a clustering of cardiometabolic risk factors (CMRFs) during adolescence that are manifested in later life. Although anthropometric variables such as body mass index (BMI) can predict cardiometabolic risk in children and adolescents, it is not clear whether there is an interaction between pubertal stage and BMI associated with cardiometabolic risk in this age group. This paper examines the association of pubertal stage and BMI with CMRFs in Hong Kong Chinese children.

METHODS

A cross-sectional school-based study was conducted among 1985 (95.1%) students aged 6 to 18 years. Fasting lipid profile and plasma glucose, blood pressure, body weight, body height and waist circumference were measured. A self-reported pubertal stage questionnaire was used to assess pubertal stage of participants. Two cardiometabolic risk scores, alpha and beta, were constructed to quantify cardiometabolic risk. Cardiometabolic risk score alpha refers to the sum of z-scores of sex-specific, age-adjusted waist circumference, height-adjusted systolic and diastolic blood pressure, fasting plasma glucose, triglyceride and low-density lipoprotein cholesterol, and minus z-score of sex-specific age-adjusted high-density lipoprotein cholesterol. Cardiometabolic risk score beta includes all components of risk score alpha except waist circumference.

RESULTS

The interaction of BMI z-score (ZBMI) and pubertal stage demonstrated a further increase in variance explained in both the cardiometabolic risk scores alpha and beta (0.5% and 0.8% respectively) in boys and (0.7% and 0.5% respectively) in girls.

CONCLUSIONS

Pubertal stage has an interaction effect on the association of cardiometabolic risk by BMI in boys and may have a similar but lesser effect in girls.

Urban-Rural Differences in Cardiovascular Disease Risk Factors: A Cross-Sectional Study of Schoolchildren in Wuhan, China

Background

China’s rapid population growth and urban migration has developed healthcare inequity across the urban-rural divide. Past studies comparing cardiovascular disease (CVD) risk factor prevalence amongst urban-rural Chinese children are sparse and conflicting. We examined the association between urban-rural residence and risk of offspring CVD in Chinese children.

Methods

A cross-sectional study was conducted in Wuhan, China, during May and June 2010. CVD risk factors include; waist circumference (WC), systolic blood pressure (SBP), diastolic blood pressure (DBP), fasting blood glucose (FBG), triglycerides (TG), high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, body mass index (BMI), cardiorespiratory fitness (CRF), metabolic syndrome (MetS), and metabolic risk score (MRS). Analysis of covariance and multivariable logistic regression were used to estimate associations between urban-rural residence and offspring CVD risks.

Findings

A total of 579 Chinese children (338 boys and 241 girls) aged 9.6 (0.7) years participated in this study. Rural boys had significantly lower CRF and higher FBG, TG, and MRS, while urban boys had significantly higher LDL and DBP. Rural girls had significantly higher BMI, FBG, and TG, as well as lower CRF. Rural children were at increased risks for decreased CRF, elevated MRS, and TG, (OR:2.04, 95%CI:1.29–3.25), (OR:2.33, 95%CI:1.50–3.62), and (OR:2.40, 95%CI:1.62–3.57), respectively. Rural girls and mothers were at increased risks for overweight(OR:7.19, 95%CI:1.64–31.6)/obesity (OR:1.683, 95%CI:1.01–2.82). However, rural boys and fathers were less likely to have overweight(OR:0.62, 95%CI:0.34–1.12)/obesity (OR:0.68, 95%CI:0.48–0.97).

Conclusions

Rural residence was significantly associated with increased CVD risks amongst Chinese children. It is important to provide interventions aiming at China’s urban-rural healthcare inequity and community-based approaches that reduce familial CVD risk.

Waist-to-height ratio and cardiometabolic risk factors in adolescence: findings from a prospective birth cohort

OBJECTIVE

To examine the associations between body mass index (BMI) and waist-to-height ratio (WHtR) measured in childhood and adolescence and cardiometabolic risk factors in adolescence.

METHODS

Secondary data analysis of the Avon Longitudinal Study of Parents and Children, a population based cohort. Data from 2858 adolescents aged 15.5 (standard deviation 0.4) years and 2710 of these participants as children aged 7-9 years were used in this analysis. Outcome measures were cardiometabolic risk factors, including triglycerides, low density lipoprotein cholesterol, high density lipoprotein cholesterol, insulin, glucose and blood pressure at 15 years of age.

RESULTS

Both BMI and WHtR measured at ages 7-9 years and at age 15 years were associated with cardiometabolic risk factors in adolescents. A WHtR ≥0.5 at 7-9 years increased the odds by 4.6 [95% confidence interval 2.6 to 8.1] for males and 1.6 [0.7 to 3.9] for females of having three or more cardiometabolic risk factors in adolescence. Cross-sectional analysis indicated that adolescents who had a WHtR ≥0.5, the odds ratio of having three or more cardiometabolic risk factors was 6.8 [4.4 to 10.6] for males and 3.8 [2.3 to 6.3] for females. The WHtR cut-point was highly specific in identifying cardiometabolic risk co-occurrence in male children and adolescents as well as female children (90 to 95%), but had poor sensitivity (17 to 53%). Similar associations were observed when BMI was used to define excess adiposity.

CONCLUSIONS

WHtR is a simple alternative to age and sex adjusted BMI for assessing cardiometabolic risk in adolescents.

A cross-sectional study to examine the association between dietary patterns and risk of overweight and obesity in Hong Kong Chinese adolescents aged 10-12 years

OBJECTIVE

To describe the dietary patterns and examine the associations of these patterns with risk of overweight and obesity in Chinese adolescents.

METHODS

Baseline data collected between November 2003 and October 2004 from 171 boys and 180 girls aged 10-12 years who participated in the Hong Kong Adolescent Bone Health Cohort Study were analyzed. Dietary intake was assessed using a food frequency questionnaire and dietary pattern calculated using factor analysis. Data on demographic characteristics, weight, height, and Tanner stage were collected. Overweight and obesity were defined using The International Obesity Task Force cutoff values. Cardiovascular fitness expressed as peak oxygen consumption was predicted using the postexercise heart rate by the 3-minute step test and was used as an objective measure of physical activity. Association between dietary patterns and risk of overweight and obesity was examined using multivariate logistic regression with adjustment for demographics, puberty, and physical activity.

RESULTS

The mean (SD) age of the study sample was 11.2 (0.6) years and there were 57 (16.2%) participants who were overweight/obese. Three dietary patterns were identified, namely, vegetables-fruits, snacks-beverages, and animal foods, fats, and condiments dominated. There was no significant linear association between each dietary pattern and the risk of overweight and obesity in this sample. Instead, the risk of overweight and obesity in this sample was positively associated with pubertal stage and inversely associated with physical activity.

CONCLUSIONS

Pubertal stage and physical activity, but not dietary patterns, were important factors contributing to the risk of overweight and obesity in this population.

A review on the genetic, environmental, and lifestyle aspects of the early-life origins of cardiovascular disease

This article is a comprehensive review on developmental origins of health and disease regarding various factors related to the origins of cardiovascular diseases from early life. It presents a summary of the impacts of various factors such as epigenetics; gene-environment interaction; ethnic predisposition to cardiovascular diseases and their underlying risk factors; prenatal factors; fetal programming; maternal weight status and weight gain during pregnancy; type of feeding during infancy; growth pattern during childhood; obesity; stunting; socioeconomic status; dietary and physical activity habits; active, secondhand, and thirdhand smoking, as well as environmental factors including air pollution and global climate change on the development and progress of cardiovascular diseases and their risk factors. The importance of early identification of predisposing factors for cardiovascular diseases for primordial and primary prevention of cardiovascular diseases from early life is highlighted.

The relationships of body mass index, waist-to-height ratio, and body fat percentage with blood pressure and its hemodynamic determinants in Korean adolescents: a school-based study

Purpose

Obesity is an important risk factor for hypertension in adolescents. We investigated the relationship of obesity-related indices (body mass index [BMI], waist-to-height ratio [WHR], and body fat percentage [%BF]) with blood pressure and the hemodynamic determinants of blood pressure in Korean adolescents.

Methods

In 2008, 565 adolescents, aged 12-16 years, were examined. The %BF of the participants was measured by bioelectrical impedance analysis. Echocardiography and brachial artery pulse tracing were used to estimate the stroke volume (SV), cardiac output (CO), total vascular resistance (TVR), and total arterial compliance (TAC).

Results

We noted that BMI, WHR, and %BF were positively correlated with systolic blood pressure (SBP) and diastolic blood pressure (DBP). The positive correlation between BMI and blood pressure (SBP and DBP) persisted after adjustment for WHR and %BF. However, after adjustment for BMI, the positive associations between blood pressure (SBP and DBP) and WHR as well as %BF, were not noted. With regard to the hemodynamic factors, BMI, but not WHR and %BF, was an independent positive factor correlated with SV and CO. TVR had an independent negative association with BMI; however, it was not associated with WHR or %BF. Moreover, we noted that BMI, WHR, and %BF did not affect TAC.

Conclusion

In Korean adolescents, BMI had an independent positive correlation with SBP and DBP, possibly because of its effects on SV, CO, and TVR. WHR and %BF are believed to indirectly affect SBP and DBP through changes in BMI.

Central adiposity and the risk of hypertension in Asian Indian girls

BACKGROUND

Elevated blood pressure during childhood is an established predictor of elevated blood pressure in adulthood. This study was undertaken to evaluate the relationship of general and central adiposity measures with hypertension and to find out the best adiposity measure in predicting hypertension.

METHODS

A cross-sectional study was carried out in 197 girls aged 5 to 16 years. Anthropometric measurements included stature, weight, waist circumference (WC) and hip circumference. Body mass index (BMI, kg/m(2)), waist hip ratio (WHR) and conicity index (CI) were calculated subsequently. Systolic blood pressure (SBP) and diastolic bold pressure (DBP) were taken and hypertension was defined as age and stature adjusted SBP and/or DBP ≥95(th) percentile. Linear and logistic regression analysis was made to determine the relationship of adiposity measure with blood pressure and hypertension and to find out the best adiposity measure in predicting hypertension.

RESULTS

Both WC [odds ratio (OR)=2.20, 95% confidence interval, 1.32-3.69] and CI (OR=1.85, 95% confidence interval, 1.14-3.0) were significantly associated with hypertension. However, there was no significant association in BMI and WHR with hypertension.

CONCLUSION

WC is the best adiposity measure in predicting hypertension in girls.

Waist circumference measurement site does not affect relationships with visceral adiposity and cardiometabolic risk factors in children

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

A number of anatomic sites are used for the measurement of waist circumference. A number of studies have documented differences in the absolute values of waist circumference measurements across these common sites in adults. It is unclear whether waist circumference measurement site alters the relationship with abdominal adiposity and cardiometabolic risk factors in children.

WHAT THIS STUDY ADDS

The absolute values of waist circumference at four anatomic locations (minimal, midway, iliac, umbilicus) differed and this affected prevalence of high (≥90th percentile) waist circumference. The relationships between waist circumference values at four anatomic locations and both depot-specific adiposity and cardiometabolic risk factors were similar across race and sex groups.

BACKGROUND

Different waist circumference (WC) measurement sites are used in clinical and epidemiological settings.

OBJECTIVES

To examine differences in WC measurement at four anatomic sites and how each WC measurement relates to visceral adipose tissue (VAT) and cardiometabolic risk factors in children.

METHODS

A total of 371 white and African-American children aged 5 to 18 years had WC measured at four sites: minimal waist, midpoint between the iliac crest and the lowest rib, superior border of the iliac crest and the umbilicus. Abdominal VAT was measured using magnetic resonance imaging and cardiometabolic risk factors were defined using National Heart, Lung and Blood Institute guidelines. Relationships between WC sites and VAT and risk factors were explored in each race-by-sex group.

RESULTS

All WC sites were highly correlated (r = 0.97 to 0.99). Differences in absolute mean WC values existed in all race-by-sex groups, and this affected the prevalence of high WC (≥90th percentile). Values were lowest for minimal waist and highest for umbilicus. Age-controlled partial correlations between WC and logVAT VAT were 0.81-0.89 (all P < 0.001) and between WC and cardiometabolic risk factors were -0.24 to -0.41 and 0.19 to 0.52 (all P < 0.05).

CONCLUSIONS

  While the absolute values of WC at four anatomic locations differed, the relationships between WC values and both VAT and cardiometabolic risk factors were similar within all race-by-sex groups.

Gender specific effect of major dietary patterns on the metabolic syndrome risk in Korean pre-pubertal children

There is a lack of data on metabolic risk factors during pre-puberty, which is important for identifying the subgroups of youth, at whom early interventions should be targeted. In this study, we evaluated the prevalence of metabolic risk factors and its subsequent relations with dietary patterns in Korean pre-pubertal children through a cross-sectional sample (n = 1,008; boys = 513) of pre-pubertal children (aged 8-9 years) from a sub-study of the Korea Metabolic Syndrome Research Initiatives (KMSRI) in Seoul, Korea. Measures of anthropometry and blood pressure as well as fasting blood samples were used in the analysis. A three-day food records were collected. The metabolic syndrome was defined according to the age-adjusted National Cholesterol Education Program Adult Treatment Panel III guidelines. An added metabolic risk score was calculated for each subject by summing the quintile values of the five individual risk factors. Among the 5 risk components of metabolic syndrome, high waist circumference (WC) was the major factor (P < 0.001). A significant increasing trend of the added metabolic syndrome risk score was observed with the increase of WC (P (trend) < 0.001) among both genders. The cutoff point for high WC for pre-pubertal children was 61.3 cm for boys and 59.9 cm for girls. The prevalence of high triglyceride (TG) values was significantly higher in girls than it was in boys (P < 0.01). Girls in the highest quintile of balanced dietary pattern scores had lower TG values (P (trend) = 0.032) than did those in the lowest quintile. Moreover, girls in the highest quintile of western dietary pattern scores showed increasing trend for the added metabolic risk score (P (trend) = 0.026) compared with those in the lowest quintile. Adverse associations exist between western dietary patterns and the accumulation of metabolic risks among girls, not in boys, even during pre-puberty.

Reference values of waist circumference and waist/hip ratio in children and adolescents of Mérida, Venezuela: comparison with international references

OBJECTIVE

To collect regional reference values of waist circumference (WC), and waist/hip ratio (WHR) in children and adolescents from Merida, Venezuela, and to compare them to international references.

SUBJECTS AND METHODS

A total of 919 students aged 9-17 years from public and private educational establishments were assessed. Weight, height, WC, and WHR were measured. Outliers (± 3 SD Z-Score) were excluded from the data collected. Percentile distribution of the tested variables was done by age and sex.

RESULTS

Fifty-one percent of subjects were female, and 52.7% were from public institutions. WC (p=0.001) and WHR (p=0.0001) were statistically higher in boys. With advancing age, WC increased in both sexes, while WHR showed the opposite behavior (p=0.0001 for both). The 90th percentile (pc) for WC ranged from 69.7 and 83.6 cm in girls and from 69.2 and 86.7 cm in boys. The 90th pc values of WHR ranged from 0.79 and 0.91 in girls and from 0.86 and 0.93 in boys. Overall, our WC and WHR values were lower than North American values and similar to those of some Latin American references.

CONCLUSION

Percentile reference charts for WC and WHR specific for age and sex, obtained from a representative sample of children and adolescents from Mérida, Venezuela, are provided. They may be used regionally, both for individual assessment and to implement prevention policies.

Validity of self-estimated adiposity assessment against general and central adiposity in Hong Kong adolescents

BACKGROUND AND AIM

The relationships between self-estimated adiposity using Stunkard's body silhouette scale with general and central adiposity in adolescents are unclear. This study examines the criterion validity of Stunkard's body silhouette scale as a self-estimated rating of adiposity against anthropometric measures of adiposity and percentage body fat in Hong Kong adolescents.

SUBJECTS AND METHODS

The body composition of 903 adolescents (55.7% boys) was assessed by measured waist circumference (WC), waist-to-stature ratio (WSR), body mass index (BMI) and percentage body fat (%BF). Self-estimated adiposity was subjectively assessed using Stunkard's body silhouette scale. The association between self-estimated adiposity and body composition was examined by Spearman correlation coefficients and hierarchical multiple regression analyses.

RESULTS

Self-estimated adiposity correlated significantly and positively with BMI (boys: r = 0.65; girls: r = 0.59), WC (boys: r = 0.62; girls: r = 0.51), WSR (boys: r = 0.55; girls: r = 0.42) and %BF (boys: r = 0.47; girls: r = 0.55).

CONCLUSION

Self-estimated adiposity using the Stunkard's body silhouette scale was positively associated with actual measures of adiposity; however, the association was modest at best. It is unlikely that the Stunkard's body silhouette scale provides a suitably accurate substitute for actual body composition measures in Chinese adolescents.

Abdominal obesity in German adolescents defined by waist-to-height ratio and its association to elevated blood pressure: the KiGGS study

OBJECTIVE

The aim of this study was to compare the fixed 0.5 cut-off and the age- and sex-specific 90th percentile (P90) for waist-to-height ratio (WHtR) in German adolescents with respect to the prevalence of abdominal obesity and to compare the screening ability of WHtR and BMI to identify hypertensive blood pressure (BP) values.

METHODS

Between 2003 and 2006, the German Health Interview and Examination Survey for Children and Adolescents (KiGGS) was carried out including 3,492 boys and 3,321 girls aged 11-17 years. Abdominal obesity was assessed by two WHtR cut-points (P90; 0.5). Hypertensive BP was defined as BP exceeding age-, sex- and height-specific 95th percentiles or the adult threshold for hypertension (140/90 mm Hg).

RESULTS

Agreement between the WHtR cut-offs was very good (Kappa 0.89 for boys; 0.81 for girls), and the prevalence of abdominal obesity was slightly higher using P90 (boys 12.0%; girls 11.3%) compared to 0.5 (boys 10.7%; girls 8.0%). WHtR and BMI-for-age had equivalent ability to discriminate hypertensive BP (ROC-AUC < 0.7; sensitivity of the 0.5 cut-off for detecting hypertensive BP < 30%).

CONCLUSION

The fixed 0.5 WHtR cut-off can be used in German adolescents to characterize abdominal obesity. However, WHtR is not suitable as a screening tool for hypertensive BP in adolescents.

BMI percentiles for the identification of abdominal obesity and metabolic risk in children and adolescents: evidence in support of the CDC 95th percentile

OBJECTIVES

Body mass index (BMI) percentiles have been routinely and historically used to identify elevated adiposity. The aim of this study was to investigate the optimal Centers for Disease Control and Prevention (CDC) BMI percentile that predicts elevated visceral adipose tissue (VAT), fat mass and cardiometabolic risk in a biracial sample of children and adolescents.

PARTICIPANTS AND METHODS

This cross-sectional analysis included 369 white and African-American children (5-18 years). BMI was calculated using height and weight and converted to BMI percentiles based on CDC growth charts. Receiver operating characteristic curve analysis identified the optimal (balance of sensitivity and specificity) BMI percentile to predict the upper quartile of age-adjusted VAT (measured by magnetic resonance imaging), age-adjusted fat mass (measured by dual-energy X-ray absorptiometry) and elevated cardiometabolic risk (≥ 2 of high glucose, triglycerides and blood pressure, and low high-density lipoprotein cholesterol) for each race-by-sex group.

RESULTS

The optimal CDC BMI percentile to predict those in the top quartile of age-adjusted VAT, age-adjusted fat mass and elevated cardiometabolic risk were the 96th, the 96th and the 94th percentiles, respectively, for the sample as a whole. Sensitivity and specificity was satisfactory (>0.70) for VAT and fat mass. Compared to VAT and fat mass, there was a lower overall accuracy of the optimal percentile in identifying those with elevated cardiometabolic risk.

CONCLUSIONS

The present findings support the utility of the 95th CDC BMI percentile as a useful threshold for the prediction of elevated levels of VAT, fat mass and cardiometabolic risk in children and adolescents.

Pedometer-determined physical activity and body composition in Chinese working adults

PURPOSE

Overweight and obesity are prevalent public health problems in many developed and developing regions. Despite extensive documentation on the health benefits of physical activities, little is known about the level of physical activity in the Hong Kong Chinese population. Working adults, in particular, deserve primary attention because they account for the largest proportion of Hong Kong society. The purposes of this study were to investigate pedometer-determined physical activity and examine the associations between physical activity and body composition variables among Chinese working adults in Hong Kong.

DESIGN

This study adopted a descriptive cross-sectional design.

METHODS

A quota sample of 913 working adults from nine major occupational categories was recruited. Demographic characteristics and body composition parameters (weight, height, and waist and hip circumferences) were assessed. Body mass index and waist-to-hip ratio were then calculated. Physical activity was measured in terms of daily walking steps using a pedometer over 1 week. Participants were then categorized as "inactive,""somewhat active," or "regularly active." Descriptive and inferential statistics (analysis of variance, t test, and χ(2) test) were used appropriately.

FINDINGS

Of the 913 participants, 893 returned complete step count records. The completion rate was 97.8%. Participants on average walked 8,661 steps per day, suggesting a "somewhat active" populace. Significant differences were found between the group "regularly active" and "inactive" in most of the body composition parameters. However, a significant weak correlation was found between physical activity and body mass index (r= 0.12, p= .001). Such findings deserve further investigation.

CONCLUSIONS

The Chinese working adults in Hong Kong were found to be somewhat active in physical activity.

CLINICAL RELEVANCE

Findings pose implications for healthcare professionals who are responsible for health promotion in the Asian community setting. Leisure-type physical activity, such as walking, can be incorporated into daily routines.

Self-reported waist circumference: a screening tool for classifying children with overweight/obesity and cardiometabolic risk factor clustering

OBJECTIVES

The objectives of this study were twofold - (i) to assess the agreement between self-reported waist circumference (SRWC) and assessor measured waist circumference (MWC) and (ii) to evaluate the diagnostic ability of SRWC for classifying (i) a clustering of cardiometabolic risk factors (CMRFs) and (ii) overweight/obese status in Hong Kong Chinese children aged 6-18 years.

METHODS

A cross-sectional study with cluster random sampling was conducted. A self-administrated questionnaire, which included demographic data, body weight, body height and waist circumference, was given to children to bring home for completion. Children were asked to return the questionnaire and fast themselves for at least 8 h on the day of the survey. Anthropometric measurements and blood pressure were taken by trained research staff and fasting blood samples were collected for measurements of fasting plasma glucose, total cholesterol, triglyceride, high-density lipoprotein cholesterol and low-density lipoprotein cholesterol.

RESULTS

A total of 515 boys and 711 girls were included in the data analysis. Agreement between SRWC and MWC was assessed by intra-class correlation coefficient and it ranged from 0.77 to 0.87. The ability of sex-specific SRWC values to classify children with a clustering of CMRFs and overweight/obesity exhibited moderately high to high sensitivity and specificity, and the area under the receiver operating characteristics ranged from acceptable to excellent (from 0.76 to 0.84).

CONCLUSIONS

SRWC has good agreement with MWC and could be used as a screening tool to classify children with a clustering of CMRFs and overweight/obesity status in Hong Kong Chinese children.

Prehypertension in children and adolescents: association with body weight and neck circumference

OBJECTIVE

The present study was undertaken to investigate the role of neck circumference (NC) in predicting prehypertension in children and adolescents.

METHODS

We conducted a cross-sectional study including 6,802 children and adolescents (3,631 boys and 3,171 girls) aged 5-18 years. Main anthropometric data and related information were collected.

RESULTS

The prevalence of prehypertension was 14.4%, 16.4% and 17.1% in normal weight, overweight and obese group respectively. Among the participants with normal body mass index (BMI), higher NC was significantly associated with increased odds of prehypertension (OR: 1.439; 95% CI: 1.118 to 1.853) after adjustment for age, gender, BMI and WC. Significant associations between NC and either systolic blood pressure (SBP) (β=0.581 mmHg) or diastolic blood pressure (DBP) (β=0.236 mmHg) were found in the linear regression. No significant ORs were observed either in overweight or in obese categories.

CONCLUSION

We concluded that additional measure of NC might expand the ability of BMI for the identification of prehypertension in normal weight 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.