Waist circumference and waist-to-height ratio percentiles in a nationally representative sample of 6-13 year old children in Switzerland

Associations between social network addiction, anxiety symptoms, and risk of metabolic syndrome in Peruvian adolescents-a cross-sectional study

Background

The link between physical and mental health and screen time in adolescents has been the subject of scientific scrutiny in recent years. However, there are few studies that have evaluated the association between social network addiction (SNA) and metabolic risk in this population.

Objective

This study determined the association between SNA and anxiety symptoms with the risk of metabolic syndrome (MetS) in adolescents.

Methods

A cross-sectional study was conducted in Peruvian adolescents aged 12 to 18 years, who completed a Social Network Addiction Questionnaire and the Generalized Anxiety Disorder 2-item scale (GAD-2), between September and November 2022. A total of 903 participants were included in the study using a non-probability convenience sample. Sociodemographic and anthropometric data were also collected. Binary logistic regression was used to explore the association between SNA and anxiety symptoms with MetS in a cross-sectional analysis.

Results

Males were more likely to have MetS than females (OR = 1.133, p = 0.028). Participants who were 16 years of age or older and those with excess body weight were 2.166, p = 0.013 and 19.414, p < 0.001 times more likely to have MetS, respectively. Additionally, SNA (OR = 1.517, p = 0.016) and the presence of anxiety symptoms (OR = 2.596, p < 0.001) were associated with MetS.

Conclusion

Our findings suggest associations between SNA, anxiety symptoms, and MetS among youth. However, more studies are needed to better understand this association and to deepen the possible clinical and public health implications.

The role of body height as a co-factor of excess weight in Switzerland

Object

Excess weight (Body Mass Index [BMI] ≥25.0 kg/m²) is a major health issue worldwide, including in Switzerland. For high‐income countries, little attention has been paid to body height in context of excess weight. The aim of this study is to assess the importance of body height as a co‐factor for excess weight in multiple large nationwide data sets.

Data and methods

In this comparative study, we included the largest nationwide and population‐based studies in the fields of public health, nutrition and economics for Switzerland, as well as data of the medical examination during conscription for the Swiss Armed Forces, which contained information on BMI and, if possible, waist‐to‐height‐ratio (WHtR) and waist‐to‐hip‐ratio (WHR).

Results

The multinomial logistic regressions show that the probability of belonging to the excess weight category (BMI ≥25.0 kg/m²) decreased with increasing height in both sexes inall contemporary data sets. This negative association was shown to be constant, only among conscripts measured in the 1870s the association was positive, when increasing height was associated with a higher BMI. The negative association not only emerge in BMI, but also in WHtR and WHR.

Conclusion

Our results emphasize the importance of body height as a co‐factor of excess weight, suggesting a clear negative association between height and BMI, WHtR and WHR. Evidence indicates that both early‐life environmental exposures and alleles associated with height may contribute to these associations. This knowledge could serve as further starting points for prevention programs in the field of public health.

Nuchal Skinfold Thickness in Pediatric Brain Tumor Patients

BACKGROUND

Severe obesity and tumor relapse/progression have impact on long-term prognosis in pediatric brain tumor patients.

METHODS

In a cross-sectional study, we analyzed nuchal skinfold thickness (NST) on magnetic-resonance imaging (MRI) follow-up monitoring as a parameter for assessment of nuchal adipose tissue in 177 brain tumor patients (40 World Health Organization (WHO) grade 1-2 brain tumor; 31 grade 3-4 brain tumor; 106 craniopharyngioma), and 53 healthy controls. Furthermore, body mass index (BMI), waist-to-height ratio, caliper-measured skinfold thickness, and blood pressure were analyzed for association with NST.

RESULTS

Craniopharyngioma patients showed higher NST, BMI, waist-to-height ratio, and caliper-measured skinfold thickness when compared to other brain tumors and healthy controls. WHO grade 1-2 brain tumor patients were observed with higher BMI, waist circumference and triceps caliper-measured skinfold thickness when compared to WHO grade 3-4 brain tumor patients. NST correlated with BMI, waist-to-height ratio, and caliper-measured skinfold thickness. NST, BMI and waist-to-height ratio were associated with increased blood pressure. In craniopharyngioma patients with hypothalamic involvement/lesion or gross-total resection, rate and degree of obesity were increased.

CONCLUSIONS

NST could serve as a novel useful marker for regional nuchal adipose tissue. NST is highly associated with body mass and waist-to-height ratio, and easily measurable in routine MRI monitoring of brain tumor patients.

International Waist Circumference Percentile Cutoffs for Central Obesity in Children and Adolescents Aged 6 to 18 Years

CONTEXT

No universal waist circumference (WC) percentile cutoffs used have been proposed for screening central obesity in children and adolescents.

OBJECTIVE

To develop international WC percentile cutoffs for children and adolescents with normal weight based on data from 8 countries in different global regions and to examine the relation with cardiovascular risk.

DESIGN AND SETTING

We used pooled data on WC in 113,453 children and adolescents (males 50.2%) aged 4 to 20 years from 8 countries in different regions (Bulgaria, China, Iran, Korea, Malaysia, Poland, Seychelles, and Switzerland). We calculated WC percentile cutoffs in samples including or excluding children with obesity, overweight, or underweight. WC percentiles were generated using the general additive model for location, scale, and shape (GAMLSS). We also estimated the predictive power of the WC 90th percentile cutoffs to predict cardiovascular risk using receiver operator characteristics curve analysis based on data from 3 countries that had available data (China, Iran, and Korea). We also examined which WC percentiles linked with WC cutoffs for central obesity in adults (at age of 18 years).

MAIN OUTCOME MEASURE

WC measured based on recommendation by the World Health Organization.

RESULTS

We validated the performance of the age- and sex-specific 90th percentile WC cutoffs calculated in children and adolescents (6-18 years of age) with normal weight (excluding youth with obesity, overweight, or underweight) by linking the percentile with cardiovascular risk (area under the curve [AUC]: 0.69 for boys; 0.63 for girls). In addition, WC percentile among normal weight children linked relatively well with established WC cutoffs for central obesity in adults (eg, AUC in US adolescents: 0.71 for boys; 0.68 for girls).

CONCLUSION

The international WC cutoffs developed in this study could be useful to screen central obesity in children and adolescents aged 6 to 18 years and allow direct comparison of WC distributions between populations and over time.

Significant Decrease in Childhood Obesity and Waist Circumference over 15 Years in Switzerland: A Repeated Cross-Sectional Study

Despite a global increase in childhood obesity over the past decades, several countries, including Switzerland, have recently reported stabilizing trends. Using national data from school-aged children in Switzerland over the past 16 years, our study aim was to assess changes in the prevalence of overweight and obesity, central adiposity and predictors of obesity related to lifestyle and parental factors. Nationally representative samples of children aged 6–12 years were studied in 2002 (n = 2493), 2007 (n = 2218), 2012 (n = 2963), and 2017/18 (n = 2279). Height and weight, waist circumference, and multiple skinfold thicknesses were measured. Potential risk factors for overweight and obesity were determined using a self-administered questionnaire in 2017/18, collecting data on diet, physical activity, and parental factors. Prevalence (95% CI) of overweight (incl. obesity) and obesity in 2017/18 was 15.9% (14.4–17.4) and 5.3% (4.5–6.3), respectively. Binary logistic regression revealed a small but significant decrease in the prevalence of overweight (including obesity) since 2002 (OR (95% CI) = 0.988 (0.978–0.997)), while the change in obesity alone was not significant. The most important risk factors for childhood overweight/obesity in 2017/18 were low parental education, non-Swiss origin of the parents, low physical activity of the child, and male sex. In conclusion, we have shown a small but significant declining trend in the childhood overweight/obesity prevalence over the past 15 years in Switzerland. Based on the risk factor analysis, preventive action in schoolchildren might be most effective in boys, migrant populations, and families with lower education, and should emphasize physical activity.

Associations between anthropometric indices, blood pressure and physical fitness performance in young Swiss men: a cross-sectional study

OBJECTIVES

To assess the benefit of waist circumference (WC) measurements during routine conscription medical examination in two military conscription centres in Switzerland. We compared the prevalence of overweight and obesity assessed by body mass index (BMI) with the prevalence of elevated disease risks assessed by WC and waist-to-height ratio (WHtR). We investigated how these measures were associated with systolic blood pressure, physical fitness performance and socioeconomic determinants.

DESIGN

Cross-sectional survey.

SETTING

Two Swiss conscription centres in 2016.

PARTICIPANTS

1548 Swiss male conscripts, 18-22 years old.

MAIN OUTCOME

Prevalences of elevated WC, WHtR and BMI values according to WHO categories. Secondary outcomes include systolic blood pressure, physical fitness performance and endurance performance.

RESULTS

Using BMI cut-points, 25.0% of all conscripts were overweight or obese. When applying WC cut-points, 9.2% had an increased disease risk, while 14.8% of the conscripts were at risk using WHtR cut-points. In the BMI range of 25.0-27.4 kg/m², 3.6% showed an increased disease risk when using WC and 24.6% when using WHtR cut-points. Of the conscripts with a BMI of 27.5-29.9 kg/m², 72.4% had an increased disease risk using WHtR, and 42.5% when using WC cut-points. Determinants of elevated BMI, WC and WHtR were low occupational status, rural residential area, older age and location in central and Northwest Switzerland. Systolic blood pressure increased with increasing BMI, WC and WHtR. Physical fitness and endurance test performances decreased with increasing BMI, WC and WHtR.

CONCLUSION

In addition to BMI, WC and WHtR add relevant information to the health assessment of young men. However, the prevalence of overweight/increased health risk differed when using BMI, WC or WHtR. Further studies should include measures of body composition to test whether these differences arise from muscular young men within the overweight BMI range, who had a normal WC.

Using LMS tables to determine waist circumference and waist-to-height ratios in Colombian children and adolescents: the FUPRECOL study

BACKGROUND

Waist circumference (WC) and waist-to-height ratio (WHtR) are often used as indices predictive of central obesity. The aims of this study were: 1) to obtain smoothed centile charts and LMS tables for WC and WHtR among Colombian children and adolescents; 2) to evaluate the utility of these parameters as predictors of overweight and obesity.

METHOD

A cross-sectional study was conducted of a sample population of 7954 healthy Colombian schoolchildren [3460 boys and 4494 girls, mean age 12.8 (±2.3) years]. Weight, height, body mass index (BMI), WC and WHtR were measured, and percentiles were calculated using the LMS method (Box-Cox, median and coefficient of variation). Appropriate cut-off points of WC and WHtR for overweight and obesity, according to International Obesity Task Force definitions, were selected using receiver operating characteristic (ROC) analysis. The discriminating power of WC and WHtR is expressed as area under the curve (AUC).

RESULTS

Reference values for WC and WHtR are presented. Mean WC increased and WHtR decreased with age for both genders. A moderate positive correlation was observed between WC and BMI (r = 0.756, P < 0.01) and between WHtR and BMI (r = 0.604, P < 0.01). ROC analysis revealed strong discrimination power in the identification of overweight and obesity for both measures in our sample population. Overall, WHtR was a slightly better predictor of overweight/obesity (AUC 95% CI 0.868-0.916) than WC (AUC 95% CI 0.862-0.904).

CONCLUSION

This paper presents the first sex and age-specific WC and WHtR percentiles for Colombian children and adolescents aged 9.0-17.9 years. The LMS tables obtained, based on Colombian reference data, can be used as quantitative tools for the study of obesity and its comorbidities.

Waist-to-height ratio and its associations with body mass index in a sample of Tuscan children in primary school

BACKGROUND

Visceral obesity in children increases the risk of developing cardiovascular diseases. To evaluate overweight children, in addition to Body Mass Index (BMI), waist-to-height ratio (WHtR) can be used to predict cardiometabolic risk. The goal of this study is to describe WHtR in a sample of Tuscan children.

METHODS

A sample of children living in the province of Pistoia, Tuscany, was measured for the following anthropometric parameters: weight, height, and waist circumference. BMI and WHtR were calculated. For the latter indicator, a threshold of 0.5 was considered as a cardiovascular risk predictor. The subjects were classified into underweight, normal weight, overweight, and obese using Cole's cut-offs.

RESULTS

The number of children enrolled were 1575 (821 males; 754 females), aged 6-11 years. Of them, 64.3% were normal weight, 4.9% underweight, 22.3% overweight, and 8.5% obese. Moreover, 12.8% had a WHtR ≥0.5 (85.7% males; 88.7% females). The average WHtR value was 0.45 ± 0.045, and was significantly different as per gender (F = 0.45 vs. M = 0.46). WHtR was significantly correlated with BMI (r = 0.766).

CONCLUSION

The average WHtR value was in line with previous studies conducted among children of similar age groups. Large-scale perspective studies are needed to validate the Italian WHtR cut-offs for children.

Nuchal Skinfold Thickness: A Novel Parameter for Assessment of Body Composition in Childhood Craniopharyngioma

CONTEXT

Hypothalamic obesity, cardiovascular disease (CVD), and relapse/progression have a major impact on prognosis in childhood-onset craniopharyngioma (CP). We analyzed nuchal skinfold thickness (NST) on magnetic resonance imaging performed for follow-up monitoring as a novel parameter for body composition (BC) and CVD in CP.

OBJECTIVE

The objective of the study was to identify the association of NST with body mass index (BMI), waist to height ratio (WHtR), functional capacity, and blood pressure (BP) in CP and controls.

DESIGN

This was a cross-sectional and longitudinal prospective study in CP patients.

SETTING

The study was conducted at HIT-Endo, KRANIOPHARYNGEOM 2000/2007.

PATIENTS

Participants included 94 CP patients and 75 controls.

INTERVENTIONS

There were no interventions.

MAIN OUTCOME MEASURES

Association of NST with BC and BP in 43 CP and 43 controls was measured.

RESULTS

NST correlated with BMI SD score (SDS; r = 0.78; P < .001; n = 169) and WHtR (r = 0.85; P < .001; n = 86) in the total cohort and CP patients (NST-BMI SDS: r = 0.77, P < .001, n = 94); NST-WHtR: r = 0.835, P < .001, n=43) and controls (NST-BMI SDS: r = 0.792, P < .001, n = 75; NST-WHtR: r = 0.671, P < .001, n = 43). In CP, systolic BP correlated with NST (r = 0.575, P < .001), BMI SDS (r = 0.434, P = .004), and WHtR (r = 0.386, P = .011). Similar results were observed for diastolic BP in CP. In multivariate analyses, NST had a predictive value for hypertension in postpubertal CP and controls (odds ratio 6.98, 95% confidence interval [1.65, 29.5], P = .008). During a longitudinal follow-up, changes in NST correlated with changes in BMI SDS (P < .001) and WHtR (P = .01) but not with changes in BP and functional capacity.

CONCLUSIONS

Because monitoring of magnetic resonance imaging and BC is essential for follow-up in CP, NST could serve as a novel and clinically relevant parameter for longitudinal assessment of BC and CVD risk in CP.

Body mass index and waist-to-height ratio cut-offs as predictors of high blood pressure in adolescents

Background: Obesity is associated with increased risk for high blood pressure (BP). Although a routine BP measurement is indicated for all children visiting pediatric practice, recognition of children particularly at risk may save times. The aim of this study was to assess the cut-off point for body mass index (BMI) and waist-to-height ratio (WHtR) to predict high BP in adolescents. Methods: We conducted a cross-sectional study on 928 children aged 11 to 16 years in Yogyakarta. BP were measured using standard technique described by The Fourth Report on The Diagnosis, Evaluation, and Treatment of High Blood Pressure in Children and Adolescents. BMI was adjusted for age and sex using the WHO 2007 growth reference. WHtR was ratio of waist circumference related to height in centimeters. Receiver operating characteristic (ROC) curves were used to estimate the best cut-offs. Results: The best cut-off point for BMI-for-age Z-score (BMIZ) to predict high BP was 0.51 with sensitivity and specificity of 82% (95% CI = 78-86) and 76% (95% CI = 67-78) for systolic BP and sensitivity and specificity of 82% (95% CI = 78-86) and 72% (95% CI = 68-76) for diastolic BP. The best cut-off point for WHtR was 0.45, with sensitivity of 76% (95% CI = 67-78) and specificity of 74% (95% CI = 71-79) for systolic BP and sensitivity of 76% (95% CI = 72-80) and specificity of 70% (95% CI = 61-75) for diastolic BP.Conclusion: BMIZ of 0.51 and WHtR of 0.45 are the best cut-off point to predict high BP in adolescents.

Pediatric adiposity stabilized in Switzerland between 1999 and 2012

PURPOSE

Several countries have recently reported stabilization and/or a decrease in the prevalence of pediatric obesity. However, systematic, repeated national monitoring studies are scarce, and it is unclear whether this trend would be sustained. The objective was to present the latest overweight and obesity prevalence in Swiss children and to investigate trends in prevalence from 1999 to 2012.

METHODS

Using probability-proportionate-to-size cluster sampling, nationally representative samples of children aged 6-12 years were recruited in 1999 (n = 594), 2002 (n = 2,493), 2004 (n = 328), 2007 (n = 2,218), 2009 (n = 907), and 2012 (n = 2,963). Height and weight were measured to calculate BMI (kg/m²). BMI cutoffs proposed by the Centers for Disease Control and Prevention (CDC) and by the International Obesity Task Force were used to determine the prevalence of overweight (excluding obesity) and obesity. Waist circumference was measured in 2007 and 2012, and multiple skinfold thicknesses assessed in 2002 and 2012.

RESULTS

Using the CDC criteria, prevalences of overweight and obesity in 2012 were 11.9 % (95 % CI 10.7-13.1) and 7.1 % (95 % CI 6.2-8.0), respectively, and did not change between 1999 and 2012 (β = -0.144, p = 0.293 and β = -0.063, p = 0.552, respectively). Boys had significantly higher obesity prevalence than girls in 2007 (5.6 vs. 3.4 %) and 2012 (8.1 vs. 5.9 %). Percentage of children with excess waist circumference and body fat percentage did not differ between 2007 and 2012, and 2002 and 2012, respectively.

CONCLUSION

Our data indicate the prevalence of childhood adiposity in Switzerland stabilized between 1999 and 2012, but ≈1 in 5 children remain overweight or obese and further efforts are needed to control the epidemic.

Application of alternative anthropometric measurements to predict metabolic syndrome

OBJECTIVE

The association between rarely used anthropometric measurements (e.g., mid-upper arm, forearm, and calf circumference) and metabolic syndrome has not been proven. The aim of this study was to assess whether mid-upper arm, forearm, calf, and waist circumferences, as well as waist/height ratio and waist-to-hip ratio, were associated with metabolic syndrome.

METHODS

We enrolled 387 subjects (340 women, 47 men) who were admitted to the obesity outpatient department of Istanbul Medeniyet University Goztepe Training and Research Hospital between September 2010 and December 2010. The following measurements were recorded: waist circumference, hip circumference, waist/height ratio, waist-to-hip ratio, mid-upper arm circumference, forearm circumference, calf circumference, and body composition. Fasting blood samples were collected to measure plasma glucose, lipids, uric acid, insulin, and HbA1c.

RESULTS

The odds ratios for visceral fat (measured via bioelectric impedance), hip circumference, forearm circumference, and waist circumference/hip circumference were 2.19 (95% CI, 1.30-3.71), 1.89 (95% CI, 1.07-3.35), 2.47 (95% CI, 1.24-4.95), and 2.11(95% CI, 1.26-3.53), respectively. The bioelectric impedance-measured body fat percentage correlated with waist circumference only in subjects without metabolic syndrome; the body fat percentage was negatively correlated with waist circumference/hip circumference in the metabolic syndrome group. All measurements except for forearm circumference were equally well correlated with the bioelectric impedance-measured body fat percentages in both groups. Hip circumference was moderately correlated with bioelectric impedance-measured visceral fat in subjects without metabolic syndrome. Muscle mass (measured via bioelectric impedance) was weakly correlated with waist and forearm circumference in subjects with metabolic syndrome and with calf circumference in subjects without metabolic syndrome.

CONCLUSION

Waist circumference was not linked to metabolic syndrome in obese and overweight subjects; however, forearm circumference, an unconventional but simple and appropriate anthropometric index, was associated with metabolic syndrome and bioelectric impedance-measured visceral fat, hip circumference, and waist-to-hip ratio.

Arterial stiffness in obese children: Role of adiposity and physical activity

OBJECTIVE

To explore association of adiposity and physical activity with arterial stiffness and to propose optimal waist circumference cutoffs, corresponding to 90(th) percentile of NHANES (National Health and Nutrition Examination Survey) for Indian children and adolescents.

MATERIALS AND METHODS

Data on weight, height, waist circumference, physical activity and right Carotid artery Intima-Media-Thickness (CIMT), pulse wave velocity (PWV), elasticity modulus (Ep), stiffness index(β), arterial compliance (AC) were assessed in 250 children (72 normal-weight and 178 overweight/obese) aged 6-17 years from Pune city, India. Body composition was measured using Dual energy X-ray absorptiometry.

RESULTS

Total, 37.1% normal-weight and 98.2% overweight/obese children had high adiposity (>95(th) body fat percentile). Positive association of PWV and Ep (r = 0.5) also β(r = 0.25) with BMI (Body Mass Index), waist circumference and body fat (P < 0.05) was observed. Physical activity was inversely associated with PWV (r =-0.2), β(r =-0.13), Ep (r =-0.12) and positively with AC (r = 0.12) (P < 0.05). PWV significantly increased with increasing body fat for each tertile of physical activity (P < 0.05). Regression analysis revealed waist circumference, BMI, body fat and physical activity as independent associates for PWV after adjusting for age (P < 0.05). The cutoff of waist circumference yielding sensitivity and specificity for predicting the risk of high PWV was (-0.43, -0.44) for boys and girls with sensitivity in boys (girls) of 78% (87%) and specificity in boys (girls) 51% (70%). The observed cutoffs are less than the NHANES-III cutoff values of waist circumference for 90(th) percentiles according to age and sex.

CONCLUSION

High adiposity and low physical activity are adversely related to arterial stiffness in Indian children.

Moderate agreement between body mass index and measures of waist circumference in the identification of overweight among 5-year-old children; the 'be active, eat right' study

BACKGROUND

Body mass index (BMI) is a common indirect method to assess weight status among children. There is evidence that BMI data alone can underestimate overweight-related health risk and that waist circumference (WC) should also be measured. In this study we investigated the agreement between BMI and WC and BMI and the waist-height ratio (WHtR) when used to identify overweight among children.

METHODS

This cross-sectional population-based study uses baseline data from 5-year-olds (n = 7703) collected by healthcare professionals for the 'Be active, eat right' study.

RESULTS

According to age-specific and sex-specific cut-off points for BMI (IOTF, 2000) and WC (Fredriks et al., 2005), the prevalence of overweight (obesity included) was 7.0% and 7.1% among boys, and 11.6% and 10.1% among girls, respectively. For the WHtR the 90th percentile was used as the cut-off point. Among boys, observed proportion of agreement between BMI and WC classification was 0.95, Cohen's kappa 0.58 (95% CI; 0.53-0.63), and proportions of positive and negative agreement were 0.61 and 0.97, respectively. Observed proportion of agreement between BMI and WHtR classification was 0.92, Cohen's kappa 0.46 (95% CI; 0.41-0.51), and proportions of positive and negative agreement were 0.51 and 0.95. Children identified as overweight according to WC were relatively tall, and children classified as overweight according to the WHtR only were relatively short (comparable results for girls).

CONCLUSIONS

There is moderate agreement between BMI and measures of WC on the presence of overweight among 5-year-olds. If BMI data and cut-offs continue to be used, then part of the group of children identified as overweight according to WC and the WHtR will be omitted. Follow-up of the children classified as overweight according to BMI only, WC only, and WHtR only, will give indications whether WC should be measured in addition to BMI or whether WC should only be measured in certain subgroups (e.g. relatively tall or short children) to identify and monitor overweight in children. This may improve early identification and prevention of overweight and overweight-related health problems in children.

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.

Waist circumference percentiles among Turkish children under the age of 6 years

Waist circumference, a proxy measure of abdominal obesity, is associated with cardio-metabolic risk factors in childhood and adolescence. Although there are numerous studies about waist circumference percentiles in children, only a few studies cover preschool children. The aim of this study was to develop age- and gender-specific waist circumference smoothed reference curves in Turkish preschool children to determine abdominal obesity prevalence and to compare them with reference curves obtained from different countries. The design of the study was cross-sectional. A total of 2,947 children (1,471 boys and 1,476 girls) aged 0-6 years were included in the study. The subjects were divided according to their gender. Waist circumference was measured by using a standardized procedure. The age- and gender-specific waist circumference reference curves were constructed and smoothed with LMS method. The reference values of waist circumference, including 3rd, 10th 25th, 50th, 75th, 90th, and 97th percentiles, and standard deviations were given for preschool children. Waist circumference values increased with age, and there were differences between genders. The prevalence of abdominal obesity was calculated as 10.1 % for boys and 10.7 % for girls. Having compared our data with two other countries' data, we found that our waist circumference data were significantly lower. This is the first cross-sectional study for age- and gender-specific references of 0- to 6-year-old Turkish children. The gender- and age-specific waist circumference percentiles can be used to determine the risk of central obesity.

Prediction of insulin resistance with anthropometric measures: lessons from a large adolescent population

OBJECTIVE

The aim of this study was to describe the minimum number of anthropometric measures that will optimally predict insulin resistance (IR) and to characterize the utility of these measures among obese and nonobese adolescents.

RESEARCH DESIGN AND METHODS

SIX ANTHROPOMETRIC MEASURES (SELECTED FROM THREE CATEGORIES: central adiposity, weight, and body composition) were measured from 1298 adolescents attending two New York City public high schools. Body composition was determined by bioelectric impedance analysis (BIA). The homeostatic model assessment of IR (HOMA-IR), based on fasting glucose and insulin concentrations, was used to estimate IR. Stepwise linear regression analyses were performed to predict HOMA-IR based on the six selected measures, while controlling for age.

RESULTS

The stepwise regression retained both waist circumference (WC) and percentage of body fat (BF%). Notably, BMI was not retained. WC was a stronger predictor of HOMA-IR than BMI was. A regression model using solely WC performed best among the obese II group, while a model using solely BF% performed best among the lean group. Receiver operator characteristic curves showed the WC and BF% model to be more sensitive in detecting IR than BMI, but with less specificity.

CONCLUSION

WC combined with BF% was the best predictor of HOMA-IR. This finding can be attributed partly to the ability of BF% to model HOMA-IR among leaner participants and to the ability of WC to model HOMA-IR among participants who are more obese. BMI was comparatively weak in predicting IR, suggesting that assessments that are more comprehensive and include body composition analysis could increase detection of IR during adolescence, especially among those who are lean, yet insulin-resistant.

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.