Waist circumference and waist-to-height ratio of Hong Kong Chinese children

Alterations in salivary biomarkers in relation to periodontal health and obesity among Hong Kong adolescents

OBJECTIVES

To explore the association among salivary biomarkers, periodontal inflammation, and adiposity status in adolescents.

METHODS

This study included 180 Hong Kong adolescents aged 12-15 years. Anthropometric measurements including central obesity surrogate, waist-to-height ratio (WHtR), and dental examinations were conducted. The participants were classified into four groups as follows: with normal WHtR and less extensive periodontal inflammation (NW+LP); with high WHtR and less extensive periodontal inflammation (HW+LP); with normal WHtR and more extensive periodontal inflammation (NW+P); and with high WHtR and more extensive periodontal inflammation (HW+P). Saliva were collected to measure salivary physicochemical parameters, total bacterial load, and levels of protein biomarkers including secretory phospholipase A2 group IIA (sPLA2-IIA) and interleukin-6 (IL-6). Data were analysed by Kruskal-Wallis test and Spearman correlation coefficient.

RESULTS

Salivary IL-6 levels and sPLA2-IIA and IL-6 output differed significantly between groups (P = 0.041, 0.027, and 0.043, respectively). The NW+P group had significantly higher salivary IL-6 output than the NW+LP group (P = 0.034) and significantly lower salivary sPLA2-IIA output than the HW+LP group (P = 0.038). Salivary IL-6 levels were negatively correlated with the number of sextants with healthy gingivae and positively correlated with salivary sPLA2-IIA levels in participants with normal WHtR. Salivary sPLA2-IIA levels were negatively correlated with total salivary bacterial load in participants with high WHtR.

CONCLUSIONS

Salivary IL-6 levels were associated with the extent of periodontal inflammation in participants with normal WHtR but not in those with high WHtR. Adolescents with different adiposity status may have different mechanisms of periodontal inflammation.

CLINICAL SIGNIFICANCE

Investigating salivary biomarkers of periodontal health holds potential benefits in identifying individuals at risk and customizing oral health promotion strategies for individuals with varying levels of adiposity, even as early as adolescence.

Population-based references for waist and hip circumferences, waist-to-hip and waist-to-height ratios for children and adolescents, and evaluation of their predictive ability

Childhood obesity is a public health problem globally as well as in Poland. This paper aimed to provide age- and sex-specific waist circumference, hip circumference, waist-to-height ratio and waist-to-hip ratio normative values for Polish children and adolescents aged 3 - 18 years for more precise monitoring of abdominal fat accumulation. The waist circumference, hip circumference, waist-to-height ratio and waist-to-hip ratio references were constructed with the lambda-mu-sigma (LMS) method using data from two nationally representative health surveys: the OLA study and the OLAF study, the largest available paediatric surveys in Poland which provided measured height, weight, waist, hip and blood pressure for 22,370 children and adolescents aged 3 - 18 years. The predictive ability of newly established references for overweight/obesity as defined by the International Obesity Task Force criteria and elevated blood pressure was tested with receiver operating characteristic. Abdominal obesity cut-offs linked to adult cardiometabolic cut-offs were established. Reference values for waist circumference, hip circumference, waist-to-height ratio and waist-to-hip ratio are presented, as well as waist circumference, waist-to-height ratio and waist-to-hip ratio cut-off values linked to adult's cut-offs of cardiometabolic risk. The predictive value for overweight and obesity of population-based waist, hip and waist-to-height ratio references was outstanding-area under the receiver operating characteristic curve > 0.95 in both sexes, whereas with regard to the elevated blood pressure predictive ability was low-area under the receiver operating characteristic curve < 0.65.   Conclusion: This paper presents the first waist, hip, waist-to-height ratio and waist-to-hip ratio references for Polish children and adolescents aged 3-18 years. The 90th and 95th percentile and cut-offs linked to adult thresholds for cardiometabolic risk are proposed as cut-offs for abdominal obesity. What is Known: • Waist circumference, waist-to-height ratio and waist-to-hip ratio are used to assess abdominal obesity in children and adults. • In Poland, there is no abdominal obesity and hip circumference references for children and adolescents from 3 to 18 years of age. What is New: • Population-based references of central obesity indices and hip references for children and youth aged 3-18 years and cardiometabolic risk thresholds for children and adolescents linked to adult's cut-offs were established.

Reference growth curves to identify weight status (underweight, overweight or obesity) in children and adolescents: systematic review

The identification of somatic growth, through reference curves, can be used to create strategies and public policies to reduce public health problems such as malnutrition and obesity and to identify underweight, overweight and obesity. The purpose of this systematic review was to identify studies providing reference growth curves for weight status in children and adolescents. A systematic search was conducted in eight databases and in gray literature (Google scholar). To assess the risk of bias/methodological quality of studies, the National Institutes of Health (NIH) Quality Assessment Tool for Observational Cohort and Cross-sectional Studies (NHLBI) was used. Overall, 86 studies that met the inclusion criteria were included. Through the values   of reference growth curves for the identification of underweight, overweight and obesity, it was possible to verify that there is great variability among percentiles for the identification of underweight, overweight and obesity. The most prevalent percentiles for underweight were P3 and P5; for overweight, the most prevalent was P85 and the most prevalent percentiles for obesity were P95 and P97. The most prevalent anthropometric indicators were Body Mass Index (BMI), Waist Circumference (WC), Body Mass (BM) for age and height for age. Conclusion: Such data can demonstrate that the optimal growth must be reached, through the standard growth curves, but that the reference curves demonstrate a cut of the population growth, raising possible variables that can influence the optimal growth, such as an increase in the practice of physical activities and an awareness of proper nutrition.

Determinants of Waist-to-Height Ratio and Its Relation to Hypertension among School Children in India: A Multicenter Study

OBJECTIVE

To study the factors associated with waist-to-height ratio (WHtR) among school children aged 5-15 y and its association with hypertension.

METHODS

In this cross-sectional study, data on background characteristics, socioeconomic status (SES), anthropometric parameters, and blood pressure were obtained from school children from three states of India. WHtR ≥ 0.5 was defined as obesity and hypertensives were defined based on Fourth Report criteria. Descriptive statistics were applied and multiple linear regression was done to identify factors associated with WHtR. A receiver operating characteristics (ROC) analysis was used to evaluate the predictive ability of WHtR to predict hypertension RESULTS: The mean WHtR among the 12,068 students was 0.40 (± 0.05) and it showed a U-shaped distribution with age with trough at 10 y of age for both genders. Mean WHtR was higher among residents of Manipur, among boys and hypertensives. WHtR was positively associated with weight > 30 kg, male gender, schools with high SES, Manipur and Goa region, and negatively associated with age > 10 y. The area under the ROC curve of WHtR for diagnosis of hypertension was low 0.544 (95% CI 0.532, 0.556).

CONCLUSION

There is a nonlinear relation between age, gender, and WHtR, which varies by geographical region and HT. This would need to be kept in mind while using it to identify obesity in children, though its discriminant value for hypertension is low.

Adiposity measures in screening for metabolic syndrome among Chinese children and adolescents

BACKGROUND

Existing various and complicated metabolic syndrome (MetS) definitions have contributed to the difficulty in assessing MetS in children and adolescents, and therefore it is urgently needed to develop a convenient and effective screening tool for pediatric MetS. This study aimed to identify the optimal adiposity measure to screen for pediatric MetS.

METHODS

The cross-sectional data was collected from 8,150 children and adolescents aged 7-17 y living in southern China. Anthropometric indices, blood lipids, and serum glucose were determined. Results of two commonly used MetS definitions were compared: International Diabetes Federation (IDF) and National Cholesterol Education Program Adult Treatment Panel Ⅲ (NCEP-ATP) modified by Cook. Receiver operating characteristic curve analyses were performed and areas under the curve (AUCs) were calculated to determine the optimal index for MetS screening.

RESULTS

MetS prevalence assessed by NCEP-ATP was significantly higher than that by IDF (6.2% vs. 1.5%, p<0.001). Waist-to-height ratio (WHtR) showed the highest screening power for MetS defined by both IDF and NCEP-ATP (AUC 0.932 and 0.900, respectively), and its optimal cut-off point was 0.48 by both IDF and NCEP-ATP definition (sensitivity 0.944 and 0.847, specificity 0.800 and 0.830, respectively), regardless of age or sex. When taking sex diversity into account, the optimal WHtR cut-off point was 0.49 (IDF) or 0.50 (NCEP-ATP) in boys, and 0.46 (both definitions) in girls.

CONCLUSIONS

Among children and adolescents aged 7-17 y in southern China, a WHtR greater than 0.48 can be a simple but effective screening tool for MetS.

Distribution of waist-to-height ratio and cardiometabolic risk in children and adolescents: a population-based study

This study was performed to evaluate the waist-to-height ratio (WHtR) distribution and assess its relationship with cardiometabolic risk in children and adolescents. A total of 8091 subjects aged 10–18 years were included from a nationally representative survey. Participants were classified into three groups: (1) < 85th, (2) ≥ 85th and < 95th, and (3) ≥ 95th percentile of WHtR. The WHtR distribution varied with sex and age. Whereas WHtR decreased from age 10–15 years in boys and from age 10–12 years in girls, it slightly increased thereafter. Compared to the < 85th percentile group, the WHtR ≥ 85th and < 95th percentile group had an odds ratio (OR) of 1.2 for elevated blood pressure (BP), 1.89 for elevated triglycerides (TGs), 1.47 for reduced high-density lipoprotein cholesterol (HDL-C) and 4.82 for metabolic syndrome (MetS). The ≥ 95th percentile group had an OR of 1.4 for elevated BP, 2.54 for elevated glucose, 2.22 for elevated TGs, 1.74 for reduced HDL-C, and 9.45 for MetS compared to the < 85th percentile group. Our results suggest that sex- and age-specific WHtR percentiles can be used as a simple clinical measurement to estimate cardiometabolic risk.

Relationship between Obesity and Oral Health Behavior in Primary and Junior High School Students: A Cross-sectional Study

It has been reported that people who brush their teeth frequently might be more health-conscious and maintain healthier lifestyle habits. The relationship between obesity and oral health behavior in childhood is unknown, however. The aim of the present study was to fill this gap by investigating obesity and factors associated with oral health behavior in Japanese primary and junior high school students. A total of 475 primary school students (fifth-grade, age 10-11 years) and 408 junior high school students (first-grade, age 12-13 years) were included. All the participants underwent a regular health check-up and completed a self-reported questionnaire. The data thus obtained were subjected to multiple logistic regression analyses to identify the relationship between obesity and factors associated with oral health behavior. In primary school students, a dislike of physical activity was the only factor showing a significant association with obesity (p<0.05). In addition, however, tooth brushing <2 times per day and a lack of regular clinical dental care showed a significant association with obesity in junior high school students (p<0.05). The present results suggest a significant association between regular clinical dental care and tooth brushing and obesity in junior school students.

Developing waist circumference, waist-to-height ratio percentile curves for Pakistani children and adolescents aged 2-18 years using Lambda-Mu-Sigma (LMS) method

Objectives Children from different countries and with different ethnic backgrounds have a distinct pattern of central fat deposition. Therefore, it is essential to develop population-specific percentiles of waist circumference (WC), waist-to-height ratio (WHtR) and waist-to-height ratio exponent (WHtR (exp)) for the evaluation of central obesity. The objective of this study was to develop age-and-gender-specific smoothed WC and WHtR percentile curves for the Pakistani children and adolescents aged 2-18 years. Methods A cross-sectional data-set from a multi-ethnic anthropometric survey was considered. A sample of 10,668 healthy subjects (boys = 51.92%; and girls = 48.08%), aged 2-18 years was studied. Height (cm) and WC (cm) of each subject was measured under standard procedure and WHtR & WHtR (exp) were calculated. Age-and-gender-specific smoothed curves were obtained using the lambda-mu-sigma (LMS) method and compared with percentile curves obtained from different countries. Results Except few early ages, the WC values increased with age in both sexes. Both boys and girls had approximately similar WC during 6-11 years of age and after age of 11, the boys had larger WC than the girls had. For WHtR, the centile curves showed a continuous decrease by 16 years of age and then increased gradually. WHtR of the girls in various ages were having similar or higher than those of the boys. In comparison of WC 50th and 90th percentiles with other countries, it was found that except few ages, the Pakistani children had larger WC than the other reference populations and the results of WHtR were also comparable to the other nations. Conclusions We present new reference data of WC, WHtR and WHtR (exp) using a representative sample of the Pakistani children aged 2-18 years. These reference values can be used provisionally for early detection of central obesity and its associated risks in the Pakistani children.

Evaluation of Hypertension, Proteinuria, and Abnormalities of Body Weight in Italian Adolescents Participating in the World Kidney Days

INTRODUCTION

World Kidney Day (WKD) was promoted by the Italian Kidney Foundation and the Italian Society of Nephrology for raising awareness, detection, prevention, and treatment of kidney diseases. The Italian WKD focused on the "School Project" by screening students attending the fifth year of high school. The main goal of the "School Project" was to assess in healthy adolescents the presence of hypertension (HTN) and proteinuria; as well as to evaluate potential interrelations between overweight, obesity (both measured with different anthropometric methods), blood pressure (BP) levels, and proteinuria. The ancillary goal was to have an estimate of awareness on some nephrology topics.

METHODS

The study population consisted of 17- to 19-year-old students. HTN was defined as systolic BP (SBP) ≥140 mm Hg and/or diastolic BP (DBP) ≥90 mm Hg. Isolated systolic hypertension (ISH) was defined as SBP ≥140 mm Hg and DBP <90 mm Hg; isolated diastolic hypertension as SBP <140 mm Hg and DBP ≥90 mm Hg; systolic and diastolic hypertension as SBP ≥140 mm Hg and DBP ≥90 mm Hg; pre-hypertension as SBP >120 mm Hg but <140 mm Hg or DBP >80 mm Hg but <90 mm Hg; and optimal BP as SBP ≤120 mm Hg and DBP ≤80 mm Hg. Urine tests were performed with a dipstick; the subjects were regarded as proteinuric when the urine dipstick was positive (proteinuria ≥30 mg/dL). Body weight, height, and waist circumference (WC) were measured; body mass index (BMI), waist-to-height ratio (WHtR), and conicity index (Ci) were calculated. According to the BMI, the following classifications were adopted: underweight (<18.5 kg/m2), normal weight (18.5-24.9 kg/m2), overweight (25-29.9 kg/m2), class-I obesity (30-34.9 kg/m2), class-II obesity (35-39.9 kg/m2), class-III obesity (≥40 kg/m2).

RESULTS

Data from 12,125 students (45.6% males) were evaluated. HTN was found in 1,349 participants (11.1%; 61.1% male), and ISH was present in 7.4%. Overweight (24.1%) and class-I (6%), -II (3.6%), and -III (1%) obesity were present in hypertensive participants. Compared to participants with normal BP, hypertensive participants had a higher BMI (p < 0.001), WC (p < 0.001), and WHtR (p < 0.001); whereas the Ci was not different (p = 0.527). Multivariate linear regression analysis showed that both WC and BMI were predictors of abnormal SBP and DBP (p < 0.001) both in males and females. Proteinuria was present in 14.8, 13.8, 14.7, and 14.7% of all normal weight, overweight, obese, and all subjects, respectively. In addition, no association was found between body weight, proteinuria, and BP.

CONCLUSION

This study shows that overweight and obesity were significantly associated to HTN in Italian adolescents. BMI and WC were predictors of SBP and DBP. The occurrence of proteinuria was quite similar to that of HTN, but it was not associated with anthropometric indicators or HTN.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Temporal changes in obesity and sleep habits in Hong Kong Chinese school children: a prospective study

We examined the temporal changes in obesity and sleep habits and their relationship in a prospective cohort of healthy Chinese adolescents. We collected data on anthropometric and questionnaire-measured sleep parameters in 2007-2008. 516 participants returned for examinations in 2013-2015. General obesity was defined as body mass index (BMI) ≥age- and sex-specific 95th percentile or ≥25 kg/m2 for participants aged <18 or ≥18 years, respectively. Central obesity was defined as waist circumference (WC) ≥ age- and sex-specific 90th percentile or using adult cut-offs. After a mean follow-up of 6.2 ± 0.5 years, the mean BMI increased from 18.5 ± 3.1 to 20.9 ± 3.4 kg/m2. The corresponding WC were 63.7 ± 8.9 and 69.8 ± 9.7 cm. General obesity rate increased from 8.3% (95% confidence interval [CI] 6.1-11.1) to 11.3% (8.7-14.4; p = 0.034). Central obesity rate decreased from 16.9% (13.7-20.4) to 13.5% (10.6-16.8; p = 0.034). During follow-up, more participants reported short sleep (<7 hours/day during weekday: 20.5% [17.1-24.2] vs. 15.3% [12.3-18.8]; p = 0.033) and bedtime after midnight (60.5% [56.2-64.8] vs. 16.2% [13.1-19.7]; p < 0.001) than baseline. The relative risk of overweight/obesity in participants with short sleep and late bedtime was 1.30 (0.48-3.47) and 1.46 (0.70-3.05), respectively. Despite rising rates of unhealthy sleep habits and general obesity, their associations were not significant at 6-year of follow-up.

Waist circumference and waist-to-height ratio in Chinese pre-school children: results from the 5th National Survey in 2015

BACKGROUND

Waist circumference (WC) and waist-to-height ratio (WHtR) distributions have been described in Chinese pre-school children only in local areas.

AIM

To report reference data of WC and WHtR in a nationally representative sample of Chinese pre-school children.

SUBJECTS AND METHODS

A total of 53,172 children aged 3-7 years were surveyed as part of the 5th National Survey in 2015. WC and WHtR percentile values were calculated for each age- and sex-specific group. Urban-suburban rural differences of WC and WHtR were examined. Comparisons of WC and WHtR with other Chinese studies and foreign studies were assessed.

RESULTS

Eleven conventional percentile values of WC and WHtR were obtained for urban and suburban rural children. Urban-suburban rural differences of WC ranged from -0.2 cm to 0.6 cm for both boys and girls across all age groups and the differences of WHtR ranged from -0.01 to 0.01. Median WC and WHtR curves were generally in the middle of other Chinese studies. Median WC and WHtR curves in China were generally lower than other countries that were compared.

CONCLUSION

The presented percentile values of WC and WHtR may be useful to monitor growth and development and to assess abdominal fat distribution of younger children.

Potential Anatomic Markers of Obstructive Sleep Apnea in Prepubertal Children

STUDY OBJECTIVES

Adenotonsillar hypertrophy is the major cause of obstructive sleep apnea (OSA) in prepubertal children, but children without enlarged lymphoid tissues may still suffer from OSA. This study aimed to identify other potential anatomic features associated with childhood OSA.

METHODS

This prospective study took place between January 2010 and April 2014. Prepubertal children suspected to have OSA, aged 6 to 11 years, were recruited. They underwent anthropometric measurements, nocturnal polysomnography, tonsil size evaluation, x-ray cephalometry, and sonographic measurement of lateral parapharyngeal wall (LPW) thickness. Linear regression analyses were used to test for the association between anatomic measurements and OSA severity. Logistic regression analyses were used to identify potential anatomic markers for different cutoffs (obstructive apneahypopnea index (OAHI) ≥ 1 and ≥ 5 events/h) for OSA.

RESULTS

Forty-seven children with OSA (20 with moderate to severe disease) and 43 children for the control group were recruited. Sonographic measurement of LPW thickness and position of hyoid bone taken from x-ray cephalometry were risk factors associated with OSA. Linear regression analyses found that these two phenotypes were associated with OAHI. Multivariate models adjusted for age, sex, body mass index, z score, and tonsil size revealed that lower position of hyoid bone was independently associated with higher risk for OSA, whereas both lower position of hyoid bone and greater LPW thickness were associated with higher OAHI and also a higher risk for moderate to severe OSA.

CONCLUSIONS

Position of hyoid bone and LPW thickness are anatomical markers of childhood OSA independent of obesity and tonsil size. Screening tools may include cephalometry and sonographic measurement of LPW to allow better delineation of OSA risk.

Secular change in waist circumference and waist-height ratio and optimal cutoff of waist-height ratio for abdominal obesity among Korean children and adolescents over 10 years

PURPOSE

This study aimed to evaluate the time trends of waist circumference (WC) and waist-height ratio (WHR), and to present WC and WHR distributions with optimal WHR cutoff for abdominal obesity in Korean children and adolescents.

METHODS

We performed a retrospective cross-sectional analysis of data from 13,257 children and adolescents (6,987 boys and 6,270 girls) aged 6-18 years who were included in the third to sixth Korea National Health and Nutrition Examination Survey (KNHANES, 2005-2015). Linear regression analyses were used to identify secular changes in WC and WHR by age, sex, and KNHANES waves. A receiver operating characteristic curve analysis was used to determine the optimal WHR cutoff values for abdominal obesity and cardiometabolic risk factors.

RESULTS

The mean WC and WHR distributions from 2005 to 2015 showed no significant secular changes between the KNHANES 4 waves (P for trend ≥0.05 in all ages and both sexes). The mean WCs in the present study were lower than those in the 2007 Korean National Growth Charts. The mean WHR at ages <13 years was statistically higher in the boys than in the girls, but did not significantly differ between the sexes among those aged 13 to 18 years. The optimal WHR cutoff for abdominal obesity was 0.48 (area under the curve, 0.985; 95% confidence interval, 0.985-0.985) in the 13- to 18-yearold adolescents.

CONCLUSION

WC and WHR showed no secular changes over 10 years. The optimal WHR cutoff for abdominal obesity of 0.48 is useful for diagnosing and managing obesity and thus preventing obesityrelated cardiometabolic complications in 13- to 18-year-old Korean adolescents.

Blood pressure is associated with body adiposity indicators in children aged 4 to 7 years

INTRODUCTION AND OBJECTIVE

Studies in adults have shown an association between increased adiposity and hypertension, but few studies have analyzed this association in childhood. The aim of this study was to investigate the association between blood pressure (BP) and body adiposity indicators in children, controlling for the variables of birth conditions, sociodemographics, lifestyle and diet.

METHODS

In this cross-sectional study of 399 children aged 4 to 7 years, the dependent variable was BP, measured according to the protocol established by the 7th Brazilian Guidelines on Hypertension. The explanatory variables of the study were waist-to-height ratio (WHtR) and body mass index (BMI). Multiple linear regression was used to assess the independent association between adiposity and BP indicators adjusted for the variables of birth conditions, sociodemographics, lifestyle and diet. Statistical significance was set as α=5%.

RESULTS

BMI for age and WHtR correlated positively with systolic (SBP) and diastolic blood pressure (DBP). After multivariate analysis, higher values of BMI (model 1) and WHtR (model 2) were associated with increased SBP and DBP.

CONCLUSION

Increased body adiposity, as assessed by BMI and WHtR, was associated with increased SBP and DBP among the children studied. Thus, we suggest the use of BMI and WHtR in the nutritional assessment of children to detect changes in BP and other cardiometabolic risk factors in this population.

Clinical usefulness of psoas muscle thickness for the diagnosis of sarcopenia in patients with liver cirrhosis

Background/Aims

The most widely used method for diagnosing sarcopenia is the skeletal muscle index (SMI). Several studies have suggested that psoas muscle thickness per height (PMTH) is also effective for detecting sarcopenia and predicting prognosis in patients with cirrhosis. The aim of this study was to evaluate the optimal cutoff values of PMTH for detecting sarcopenia in cirrhotic patients.

Methods

All cirrhotic patients who underwent abdominal computed tomography (CT) scan including L3 and umbilical levels for measuring SMI and transverse psoas muscle thickness, respectively, were included. Two definitions of sarcopenia were used: (1) sex-specific cutoffs of SMI (≤52.4 cm² /m² in men and ≤38.5 cm² /m² in women) for SMI-sarcopenia and (2) cutoff of PMTH (<16.8 mm/m) for PMTH-sarcopenia.

Results

Six hundred fifty-three patients were included. The average age was 53.6 ± 10.2 years, and 499 patients (76.4%) were men. PMTH correlated well with SMI in both men and women (P<0.001). Two hundred forty-one (36.9%) patients met the criteria for SMI-sarcopenia. The best PMTH cutoff values for predicting SMI-sarcopenia were 17.3 mm/m in men and 10.4 mm/m in women, and these were defined as sex-specific cutoffs of PMTH (SsPMTH). The previously published cutoff of PMTH was defined as sex-nonspecific cutoff of PMTH (SnPMTH). Two hundred thirty (35.2%) patients were diagnosed with SsPMTH-sarcopenia, and 280 (44.4%) patients were diagnosed with SnPMTH-sarcopenia. On a multivariate Cox regression analysis, SsPMTH-sarcopenia (hazard ratio [HR], 1.944; 95% confidence interval [CI], 1.144–3.304; P=0.014) was significantly associated with mortality, while SnPMTH-sarcopenia was not (HR, 1.446; 95% CI, 0.861–2.431; P=0.164).

Conclusions

PMTH was well correlated with SMI in cirrhotic patients. SsPMTH-sarcopenia was an independent predictor of mortality in these patients and more accurately predicted mortality compared to SnPMTH-sarcopenia.

Agreement between self-/home-measured and assessor-measured waist circumference at three sites in adolescents/children

The objective of this study was to assess the validity of the self-/home-measured waist circumference (WC) method in children/adolescents at three sites: at the level of the umbilicus, immediately above the iliac crest, and at the midpoint of the lower margin of the last palpable rib and top of the iliac crest. A cross-sectional study of 3360 Hong Kong Chinese children/adolescents was conducted, with 2980 (88.7%) participants included in the final analysis. The WC of children aged 6 to 9 was measured at the three sites by their parent/guardian at home followed by measurement by trained assessors at school within one week. Children/adolescents between the ages of 10 and 17 self-measured their WC at the three sites during school hours, followed by measurements by the trained assessors. Bland-Altman limits of agreement (LOA) analysis was performed to evaluate between-measurement agreement. The difference between assessor- and self-/home-measured WC was defined as ≤ ±2.5 cm for the upper and lower LOA at all three sites as an a priori criterion based on the assessor-measured inter-rater results. The results showed that most measurements (about 96%) at each site was within 95% of the LOA. Of the three measurement sites, the smallest LOA interval width was found at the umbilicus site, with an upper LOA of 5.08 and 7.13 and lower LOA of -2.61 and -3.43 in boys and girls, respectively. In conclusion, the range of LOA was relatively large, exceeding the acceptable limits of the predefined a priori criterion of upper and lower LOA, and thus suggesting disagreement between the two measurement methods. The use of WC as a measure of abdominal obesity in clinical practice/epidemiological studies should be restricted to measurement by trained health professionals/research staff.

Plasma IL-1 Receptor Antagonist Concentration Has an Inverse Association With Birth Weight in Prepubertal Children

Context:

Birth size has an impact on later cardiometabolic risk that is strongly related to low-grade inflammation.

Objective:

To evaluate plasma interleukin-1 receptor antagonist (IL-1ra) concentrations in relation to birth size and cardiometabolic and inflammatory markers in prepubertal children.

Design:

A cohort study. Anthropometric data were recorded. Fasting blood samples were collected for plasma analyses of IL-1ra, alanine transaminase, total cholesterol, high- and low-density lipoprotein cholesterols, triglyceride, glucose, and serum analyses of 25-hydroxyvitamin D [25(OH)D] and high-sensitivity C-reactive protein (hs-CRP) concentrations.

Participants:

Forty-nine large for gestational age (LGA), 56 appropriate for gestational age, and 23 small for gestational age (SGA) children at 5 to 8 years of age were examined.

Main Outcome Measures:

Differences in IL-1ra concentrations among the birth-size groups and associations between IL-1ra and other metabolic markers were assessed.

Results:

Body mass index (BMI) standard deviation score (SDS)-adjusted plasma IL-1ra concentrations were highest in the SGA- and lowest in the LGA-born children (P = 0.015). Age- and sex-adjusted IL-1ra concentrations had strongest associations with BMI SDS (P < 0.001) and hs-CRP (P < 0.001, also when further adjusted for BMI SDS).

Conclusions:

Prepubertal children born SGA had the highest and those born LGA the lowest IL-1ra concentrations in this study cohort. Most associations found between IL-1ra and the studied metabolic parameters were weight related, but the association with hs-CRP remained strong after adjustment for BMI. It seems that at prepuberty, SGA children have a stronger inflammatory state than LGA children and may thus be at a greater risk for later metabolic disturbances.

Association of Wrist Circumference and Waist-to-Height Ratio with Cardiometabolic Risk Factors among Type II Diabetics in a Ghanaian Population

The study determined the association of wrist circumference (WrC) and waist-to-height ratio (WHtR) with cardiometabolic risk factors among diabetics in a Ghanaian population. This cross-sectional study involved 384 diabetic patients at Begoro District Hospital, Ghana. Blood pressure, anthropometrics, and biochemical indices were measured. The overall prevalence of dyslipidaemia, metabolic syndrome (MetS), and hypertension was 42.4%, 76.3%, and 39.8%, respectively. The optimum cut-off range of WrC to identify individuals at increased cardiometabolic risk was 17.5 to -17.8 cm for men and 16.0 to 16.7 cm for women while that of WHtR was 0.52 to 0.61 for men and 0.53 to 0.59 for women. WrC for women was a significant independent predictor for MetS [aOR = 3.0 (1.39-6.72), p = 0.005] and systolic blood pressure [aOR = 2.08 (1.17-3.68), p = 0.012]. WHtR was a significant positive predictor for triglycerides [aOR = 3.23 (0.10-3.82), p = 0.001] for women. Using Framingham risk scores, 61% of the subjects had elevated 10-year risk of developing cardiovascular diseases (CVDs), with no significant difference in gender prevalence. WrC [aOR = 6.13 (0.34-111.4), p = 0.107] and WHtR [aOR = 2.52 (0.42-15.02), p = 0.309] were associated with statistically insignificant increased odds of moderate-to-high risk of developing CVDs in 10 years. The use of gender-specific cut-offs for WrC and WHtR may offer putative markers for early identification of CRFs.

Predictive Value of Serum Gamma-glutamyltranspeptidase for Future Cardiometabolic Dysregulation in Adolescents- a 10-year longitudinal study

Serum gamma-glutamyltransferase (γ-GT) is implicated in the pathogenesis of atherosclerosis and metabolic syndrome (MetS) in adults. The relationships between γ-GT and cardiometabolic dysregulation remains unclear in adolescents. We enrolled 7,072 Taiwanese adolescents and followed them for a median of 6.8 years. The optimal cut-off values (CoVs) of baseline γ-GT to predict future MetS, hypertension (HTN), and type 2 diabetes (T2DM) were determined by receiving operating characteristic (ROC) curve. Using these CoVs, the participants were divided into normal- and high-level groups. Cox proportional hazard analysis was used to calculate hazard ratios (HRs) for the subjects with a high level of γ-GT for the risk of future cardiometabolic dysregulation. Serum γ-GT was significantly higher in the subjects with MetS than in those without MetS at baseline (p < 0.001). The optimal CoVs of γ-GT were 12 U/L for boys and 11 U/L for girls. In multivariate Cox regression analysis, a higher serum γ-GT level increased the risk of future MetS (HRs 1.98 and 2.85 for boys and girls, respectively, both p < 0.001), but not new onset HTN and T2DM. In conclusion, serum γ-GT levels not only demonstrated an excellent correlation with the presence of MetS and also in predicting future MetS in 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.

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

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

Height-adjusted percentiles evaluated central obesity in children and adolescents more effectively than just waist circumference

AIM

We compared the prevalence of obesity based on both waist circumference for height and body mass index (BMI) in Iranian children and adolescents.

METHODS

Data on 13 120 children with a mean age of 12.45 ± 3.36 years (50.8% male) from the fourth Childhood and Adolescence Surveillance and Prevention of Adult Non-communicable Disease study were included. Measured waist circumference values were modelled according to age, gender and height percentiles. The prevalence of obesity was estimated using the 90th percentiles for both unadjusted and height-adjusted waist circumferences and compared with the World Health Organization BMI cut-offs. They were analysed further for short, average and tall children.

RESULTS

Waist circumference values increased steadily with age. For short and average height children, the prevalence of obesity was higher when height-adjusted waist circumference was used. For taller children, the prevalence of obesity using height-adjusted waist circumference and BMI was similar, but lower than the prevalence based on measurements unadjusted for height. Height-adjusted waist circumference and BMI identified different children as having obesity, with overlaps of 69.47% for boys and 68.42% for girls.

CONCLUSION

Just using waist circumference underestimated obesity in some Iranian children and measurements should be adjusted for height.

[Anthropometric indices among schoolchildren from a municipality in Southern Brazil: a descriptive analysis using the LMS method]

OBJECTIVE:

To describe the percentile values for body mass index (BMI), waist circumference (WC) and waist-to-height (WHtR) of children from Colombo, Brazil, and compare them with data of children from other countries.

METHODS:

This was a cross-sectional study with a random sample of 2,035 children aged 6-11 years. Age- and sex-specific smoothed percentiles curves for BMI, WC and WHtR were created using the LMS method. Values of 10^th, 50^th and 90^th percentiles from Brazilian children were compared with data from other countries.

RESULTS:

There was a trend of increasing BMI and WC with age in both sexes. WHtR remained constant with advancing age in boys and girls. Comparison of the growth pattern among countries showed clear differences. Southern Brazil boys and girls had elevated 90^th percentile values for BMI, which was similar to German children and higher than the North American and World Health Organization percentile values. However, children from this study had intermediate values for WC and WHtR in comparison to children from other countries.

CONCLUSIONS:

Elevated BMI values were observed among southern Brazilian children, but WC and WHtR percentile values were lower in southern Brazilian children than in children from other countries. Interventions at different levels should be made to avoid a probable increase of nutritional disorders (especially general obesity) in the next years.

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.

Excellent Intra and Inter-Observer Reproducibility of Wrist Circumference Measurements in Obese Children and Adolescents

In a previous study, we found that wrist circumference, in particular its bone component, was associated with insulin resistance in a population of overweight/obese children. The aim of the present study was to evaluate the intra- and inter-operator variability in wrist circumference measurement in a population of obese children and adolescents. One hundred and two (54 male and 48 female) obese children and adolescents were consecutively enrolled. In all subjects wrist circumferences were measured by two different operators two times to assess intra- and inter-operator variability. Statistical analysis was performed using SAS v.9.4 and JMP v.12. Measurements of wrist circumference showed excellent inter-operator reliability with Intra class Correlation Coefficients (ICC) of 0.96 and ICC of 0.97 for the first and the second measurement, respectively. The intra-operator reliability was, also, very strong with a Concordance Correlation Coefficient (CCC) of 0.98 for both operators. The high reproducibility demonstrated in our results suggests that wrist circumference measurement, being safe, non-invasive and repeatable can be easily used in out-patient settings to identify youths with increased risk of insulin-resistance. This can avoid testing the entire population of overweight/obese children for insulin resistance parameters.

Waist circumference percentiles for Singaporean children and adolescents aged 6-17 years

AIM

Population-specific waist circumference (WC) percentiles are crucial for screening children at higher obesity-related metabolic risk. This study aimed to develop age- and gender-specific WC percentile curves for Singaporean children and adolescents.

METHODS

3029 participants (boys, 1506; girls, 1523) from different population strata of Singapore were recruited. Stature, weight and WC were measured and BMI calculated. Smoothed WC percentile curves and cut-offs for the 3rd, 5th, 10th, 25th, 50th, 75th, 85th, 90th, 95th, 97th were constructed using the Cole's LMS method.

RESULTS

WC and BMI increased with age in both sexes and boys had higher WC than girls at every age. Comparison of 50th and 90th percentiles with other populations showed distinct difference in WC curve patterns and values of Singaporean children.

CONCLUSIONS

We present the first working WC percentile curves and age- and gender-specific cut-offs of Singaporean children and adolescents. These cut-offs and curves can serve as valuable reference for screening and identify children at a higher metabolic risk, for international comparisons and to better understand secular trends in paediatric obesity.

Health Outcomes of Information System Use Lifestyles among Adolescents: Videogame Addiction, Sleep Curtailment and Cardio-Metabolic Deficiencies

BACKGROUND AND OBJECTIVE

Obesity is a rising problem among adolescents in modern societies; it results in long-term cardio-metabolic problems. Possible overlooked drivers of obesity and its consequent cardio-metabolic deficits include videogame addiction and the resulting curtailed sleep; both are growing problems among adolescents. The objective of this study is to examine possible associations among these concepts in adolescents, as a means to point to plausible interventions.

METHODS

Data were collected from 94 adolescents who play videogames and are enrolled in outpatient clinics, using surveys, wearable sleep monitors (FitBit), physical exams, and blood tests at three points in time. These data were subjected to structural equation modeling (SEM) analyses and bootstrapping-based mediation testing procedures.

RESULTS

Videogame addiction among adolescents was negatively associated with sleep duration (β = -0.24). Sleep duration was negatively associated with obesity (β = -0.30), which in turn was associated with elevated blood pressure (β = 0.26), low high-density lipoprotein cholesterol (β = -0.18), high triglycerides (β = 0.61), and high insulin resistance (β = 0.39). The model explained 36.2% of the variation in sleep duration, 32.7% of the variation in obesity, and between 12.8% and 28.1% of the variation in cardio-metabolic indicators. Post-hoc analyses indicated that curtailed sleep is a possible full mediator of the association between videogame addiction, abdominal obesity and the associated cardio-metabolic deficits.

CONCLUSION

The findings point to possible information systems use lifestyle-health links, which behooves researchers and practitioners to pay closer attention to possible adverse health outcomes of technology-related addictions. Interventions that target problematic video-gaming and sleep should be devised as a possible means for improving adolescents' long-term cardio-metabolic health.

Waist-to-Height Ratio as an Index for Cardiometabolic Risk in Adolescents: Results from the 1998-2008 KNHANES

PURPOSE

To describe the relationship between the waist-to-height ratio (WHtR) and cardiometabolic risk factors (CMRFs) and to evaluate the validity of WHtR in identifying adolescents with metabolic syndrome.

MATERIALS AND METHODS

We analyzed data from a pooled population of 4068 adolescents aged 10-19 years from the Korean National Health and Nutrition Examination Surveys conducted between 1998 and 2008. Overweight individuals were defined by body mass index (BMI) ≥85th percentile. Those with at least 2 CMRFs among hypertension, hyperglycemia, hypertriglyceridemia, and decreased high-density lipoprotein cholesterol (HDL-C) were classified as having multiple CMRFs.

RESULTS

WHtR was significantly related to systolic blood pressure, HDL-C, and triglycerides in both non-overweight and overweight adolescents (all p<0.01). Among overweight adolescents, the area under the curve (AUC) for WHtR in identifying multiple CMRFs was significantly greater than that for BMI (p=0.014). Metabolic syndrome was more common in overweight adolescents with a WHtR of ≥0.5 than in those with a WHtR of <0.5 (p<0.001). In non-overweight adolescents, the prevalences of multiple CMRFs (p=0.001) and metabolic syndrome (p<0.001) were higher in those with a WHtR of ≥0.5 than in those with a WHtR of <0.5. Among those without central obesity, the prevalence of multiple CMRFs was higher in those with a WHtR of ≥0.5 than in those with a WHtR of <0.5 (p=0.021).

CONCLUSION

WHtR is a simple and valid index for identifying adolescents with increased cardiometabolic risk and is related to CMRFs even in non-overweight adolescents. In adolescents already screened via BMI and waist circumference (WC), WHtR seems to be of additional help in discriminating those at higher cardiometabolic risk.

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.

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

BACKGROUND

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSION

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

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.

High Discrepancy in Abdominal Obesity Prevalence According to Different Waist Circumference Cut-Offs and Measurement Methods in Children: Need for Age-Risk-Weighted Standardized Cut-Offs?

Background

Waist circumference (WC) is a good proxy measure of central adiposity. Due to the multiplicity of existing WC cut-offs and different measurement methods, the decision to use one rather than another WC chart may lead to different prevalence estimates of abdominal obesity in the same population. Aim of our study was to assess how much the prevalence of abdominal obesity varies in Italian schoolchildren using the different available WC cut-offs.

Methods

We measured WC at just above the uppermost lateral border of the right ilium in 1062 Italian schoolchildren aged 7–14 years, 499 living in Northern Italy and 563 in Southern Italy. Abdominal obesity was defined as WC ≥90^th percentile for gender and age according to nine WC charts.

Results

We found an extremely high variability in the prevalence of abdominal obesity detected in our study-populations according to the different WC charts, ranging in the overall group from 9.1% to 61.4%. In Northern Italy children it varied from 2.4% to 35.7%, and in Southern ones from 15.1% to 84.2%.

Conclusions

On the basis of the chosen WC cut-offs the prevalence of abdominal obesity varies widely, because percentile-charts are strongly influenced by the population status in a particular moment. A further rate of variability may lay on the site of WC measurement and on the statistical method used to calculate WC cut-offs. Risk-weighted WC cut-offs measured in a standardized anatomic site and calculated by the appropriate method are needed to simply identify by WC measurement those children at high risk of cardio-metabolic complications to whom specific and prompt health interventions should be addressed.

Uric Acid Levels Can Predict Metabolic Syndrome and Hypertension in Adolescents: A 10-Year Longitudinal Study

The relationships between uric acid and chronic disease risk factors such as metabolic syndrome, type 2 diabetes mellitus, and hypertension have been studied in adults. However, whether these relationships exist in adolescents is unknown. We randomly selected 8,005 subjects who were between 10 to 15 years old at baseline. Measurements of uric acid were used to predict the future occurrence of metabolic syndrome, hypertension, and type 2 diabetes. In total, 5,748 adolescents were enrolled and followed for a median of 7.2 years. Using cutoff points of uric acid for males and females (7.3 and 6.2 mg/dl, respectively), a high level of uric acid was either the second or third best predictor for hypertension in both genders (hazard ratio: 2.920 for males, 5.222 for females; p<0.05). However, uric acid levels failed to predict type 2 diabetes mellitus, and only predicted metabolic syndrome in males (hazard ratio: 1.658; p<0.05). The same results were found in multivariate adjusted analysis. In conclusion, a high level of uric acid indicated a higher likelihood of developing hypertension in both genders and metabolic syndrome in males after 10 years of follow-up. However, uric acid levels did not affect the occurrence of type 2 diabetes in both genders.

Waist-to-height ratio centiles by age and sex for Japanese children based on the 1978-1981 cross-sectional national survey data

OBJECTIVES

To construct waist-to-height ratio (WC/Ht) reference values and centile curves for Japanese children and to compare these references with those from other countries.

METHODS

The 1978-1981 national survey data were used for reference and the 1992-1994 national survey data were used for validation. The former included 19 233 children, and the latter included 10 446 children, aged 6 to 18 years. Waist circumferences (WC) were measured at the level of maximum waist narrowing in girls, and at the level of the top of the iliac crest in boys. Age- and sex-specific reference curves were fitted with the LMS method. Cut-off points were arbitrarily set at 85th, 90th, 95th and 97th centiles, and compared with WC/Ht 0.50.

RESULTS

The proportion of children in whom WC/Ht exceeded 0.50 was 18.7% of boys and 1.9% of girls, whereas the proportion of children exceeding 90th centile was 42.4% for boys and 17.3% for girls. The reference values decreased with age in girls but varied by age without a clear trend in boys.

CONCLUSIONS

The first reference values for WC/Ht are provided for Japanese youth based on the 1978-1981 national survey data. These curves are age- and sex-dependent, precluding the use of universal cut-off for WC/Ht of 0.50.

TriGlycerides and high-density lipoprotein cholesterol ratio compared with homeostasis model assessment insulin resistance indexes in screening for metabolic syndrome in the chinese obese children: a cross section study

BACKGROUND

Metabolic Syndrome (MS) is prevalant in China, especially according to the pediatric obesity group. Based on the MS-CHN2012 definition for Chinese children and adolescents the need to explore and establish a convienent MS screening become imminent. This study aims to investigate the optimal cut-off values, compare the accuracy for the (TriGlycerides (TG) to High-Density Lipoprotein Cholesterol (HDL-C)) (TG/HDL-C) ratio and Homeostasis Model Assessment Insulin Resistance (HOMA-IR) indexs to identify Metabolic Syndrome in obese pediatric population in China.

METHOD

A total sample of 976 children (female 286 male 690, BMI > = 95 percentile) aged from 6-16 years underwent a medical assessment including a physical examination and investigations of total cholesterol, high-density lipoprotein, low-density lipoprotein, triglycerides, insulin, glucose, and oral glucose tolerance test to identify the components of Metabolic Syndrome. The validity and accuracy between TG/HDL-C ratio and HOMA-IR were compared by Receiver Operating Characteristics analysis (ROC).

RESULT

TG/HDL-C ratio achieved a larger ROC Area under Curve (AUC = 0.843) than HOMA-IR indexes (0.640, 0.625 for HOMA1-IR, HOMA2-IR respectively) to screen for Metabolic Syndrome. The cut-off values for MS were: TG/HDL-C ratio > 1.25 (sensitivity: 80%; specificity: 75%), HOMA1-IR > 4.59 (sensitivity: 58.7%; specificity: 65.5%) and HOMA2-IR > 2.76 (sensitivity: 53.2%; specificity: 69.5%). The results kept robust after stratified by gender, age group and pubertal stage.

DISCUSSION

TG/HDL-C ratio was a better indicator than the HOMA-IR to screen for a positive diagnosis for MS. Furthermore, the TG/HDL-C ratio was superior to the HOMA-IR indexes even after the control of possible confusions from the gender, age group and puberty stage.

CONCLUSION

TG/HDL-C ratio proved a better index than HOMA-IR in screening for MS in obese children and adolescents. TG/HDL-C ratio has a discriminatory power in detecting potential MS in the Chinese obese pediatric population.

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.

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

INTRODUCTION

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Anthropometry and body composition of adolescents in cracow, poland

Background and Objective

The aim of the present study was to determine the level of adiposity and obesity in Polish adolescents and compare the results with earlier studies conducted in this population as well as those carried out in other populations.

Methods

The study group consisted of 456 boys and 514 girls aged 14-18 years living in Cracow chosen from randomly selected secondary schools. Weight, height, waist, and hip circumference (WC, HC) as well as triceps, biceps, subscapular, and suprailiac skinfold thickness (SFT) were measured. Body mass index (BMI), waist-to-hip ratio (WHR), waist-to-height ratio (WHtR), subscapular/triceps skinfold ratio (STR), and percentage body fat were computed. The prevalence of overweight and obesity based on Polish children growth reference were calculated and age-dependent and gender-specific smoothed percentile curves for BMI and ROC curves were generated.

Results

Weight, height, WC, HC (up 16yr), WHtR (up 15yr), and WHR were considerably higher in males than females. Weight, height, and HC increased with age; WHtR remained the same. The prevalence of overweight and obesity were 10.2% (boys 10.3%; girls 10.1%) and 4.2% (boys 5.3%; girls 3.3%). ROC analysis revealed that WHtR was the best tool for detection of obesity (AUC of 0.982±0.007) in males, whereas the sum of four SFTs (AUC: 0.968±0.011) and WHtR (AUC: 0.963±0.012) were the best predictors of obesity in females.

Conclusions

The level of adiposity in Cracow adolescents increased during the last decade. However, it is still lower than in other well-developed societies struggling with obesity epidemics.

Anthropometric indices among schoolchildren from a municipality in Southern Brazil: a descriptive analysis using the LMS method

OBJECTIVE: To describe the percentile values for body mass index (BMI), waist circumference (WC) and waist-to-height (WHtR) of children from Colombo, Brazil, and compare them with data of children from other countries.METHODS: This was a cross-sectional study with a random sample of 2,035 children aged 6-11 years. Age- and sex-specific smoothed percentiles curves for BMI, WC and WHtR were created using the LMS method. Values of 10th, 50th and 90th percentiles from Brazilian children were compared with data from other countries.RESULTS: There was a trend of increasing BMI and WC with age in both sexes. WHtR remained constant with advancing age in boys and girls. Comparison of the growth pattern among countries showed clear differences. Southern Brazil boys and girls had elevated 90th percentile values for BMI, which was similar to German children and higher than the North American and World Health Organization percentile values. However, children from this study had intermediate values for WC and WHtR in comparison to children from other countries.CONCLUSIONS: Elevated BMI values were observed among southern Brazilian children, but WC and WHtR percentile values were lower in southern Brazilian children than in children from other countries. Interventions at different levels should be made to avoid a probable increase of nutritional disorders (especially general obesity) in the next years.

Waist Circumference, Waist-to-Height Ratio and Body Mass Index of Thai Children: Secular Changes and Updated Reference Standards

BACKGROUND

The prevalence of obesity in pediatric age group has been increasing globally. Body mass index (BMI), waist circumference (WC) and waist-to-height ratio (WHtR) are commonly used to define obesity. The cut-off references for these parameters vary between racial and ethnic groups. We aimed to measure the secular changes and update the reference standards for these three parameters for Thai children in this study.

MATERIALS AND METHODS

We completed a cross-sectional survey of 3,885 school children 6.0-12.99 y of age in Ongkharak district of central Thailand during May to June 2013. Weight, height and WC were recorded by trained staff using sensitive and calibrated instruments. BMI and WHtR were calculated by standard formulae. The summary estimates were described by gender and whole year age groups. Age and gender specific smoothened percentile curves were created by using least mean squares method. The data was compared with that from a 2008 cohort from the same area.

RESULTS

Age and gender specific percentile data and curves of WC, WHtR and BMI have been provided for Thai children. BMI and WC increased but WHtR changed relatively little with age in both genders. In comparison to 2008, WC and WHtR have increased consistently across all age groups and both genders. The 75th percentile for WHtR corresponded closely to 0.50 in both genders which has been the suggested cut-off.

CONCLUSION

Since 2008, there have been significant increase in WC and WHtR across all age groups and in both genders in Thai children. These indicate increasing prevalence of central obesity and upcoming cardio-metabolic health problems. This needs to be tackled urgently by creating awareness and promotion of healthy diets and physical activities in school children. WC and WHtR should be routinely measured in paediatric examination for early diagnosis of central obesity.

Waist-to-height ratio percentiles and cutoffs for obesity: a cross-sectional study in brazilian adolescents

This study aimed to describe the distribution of waist-to-height ratio (WHtR) percentiles and cutoffs for obesity in Brazilian adolescents. A cross-sectional study including adolescents aged 10 to 15 years was conducted in the city of São Paulo, Brazil; anthropometric measurements (weight, height, and waist-circumference) were taken, and WHtRs were calculated and then divided into percentiles derived by using Least Median of Squares (LMS) regression. The receiver operating characteristic (ROC) curve was used in determining cutoffs for obesity (BMI ≥ 97th percentile) and Mann-Whitney and Kruskal-Wallis tests were used for comparing variables. The study included 8,019 adolescents from 43 schools, of whom 54.5% were female, and 74.8% attended public schools. Boys had higher mean WHtR than girls (0.45 ± 0.06 vs 0.44 ± 0.05; p=0.002) and higher WHtR at the 95th percentile (0.56 vs 0.54; p<0.05). The WHtR cutoffs according to the WHO criteria ranged from 0.467 to 0.506 and 0.463 to 0.496 among girls and boys respectively, with high sensitivity (82.8-95%) and specificity (84-95.5%). The WHtR was significantly associated with body adiposity measured by BMI. Its age-specific percentiles and cutoffs may be used as additional surrogate markers of central obesity and its co-morbidities.

Prevalence of Metabolic Syndrome in Thai Children: A Cross-sectional Study

BACKGROUND

Metabolic syndrome in children has become the focus of many research projects in recent years. The main goal of this study is to evaluate the prevalence of metabolic syndrome in Thai children and its correlation with overweight and obesity.

MATERIAL AND METHODS

A cross-sectional study of 348 children enrolled in grade 1 to grade 9 was done in Ongkhaluck province in Thailand. Demographic and anthropometric data were gathered. Blood tests were also performed to check for blood glucose, total cholesterol, and triglycerides.

RESULTS

The overall prevalence of metabolic syndrome in our population was 4.0%. Metabolic syndrome was found in 0.7% of non-obese/non-overweight children and 17.6% of obese/overweight children. Participants with metabolic syndrome were found to be significantly older, heavier, and taller and to have higher parameters of adiposity when compared with those without metabolic syndrome. Obesity was significantly correlated with every criterion of diagnosis of metabolic syndrome except Impaired Fasting Glucose (IFG).

CONCLUSION

Findings of this study suggest that the prevalence of metabolic syndrome in Thai children is consistent with other reports from across the world.

Percentiles of waist-hip ratio and the relationship with blood pressure among children and adolescents in Shandong, China

BACKGROUND

Anthropometric indices such as waist circumference (WC), waist-to-height ratio (WHtR) and waist-hip ratio (WHR) have been recognized as useful alternatives to visceral fat measurement in epidemiological studies. WHR has been used extensively in adults. However, there are very few published data for WHR among children and adolescents.

AIM

The present study examined the distribution of WHR and the relationship with blood pressure (BP) among children and adolescents in Shandong, PR China.

SUBJECTS AND METHODS

Data for this study were obtained from a large cross-sectional survey of schoolchildren carried out in 2010. A total of 38,822 students (19,456 boys and 19,366 girls) aged 7-17 years participated in this study. WC, Hip circumference (HC), systolic blood pressure (SBP) and diastolic blood pressure (DBP) of all subjects were measured; WHR was calculated as WC divided by HC. Abdominal obesity was defined by previously published WHR references based on Chinese children and adolescents living in Beijing. All subjects were divided into two groups (group 1 with WHR <85th; group 2 with WHR ≥85th) according to the percentiles of WHR and comparisons of the SBP and DBP between the two groups were made.

RESULTS

The WHR levels in Shandong boys and girls were lower than those from German and Pakistani. The overall prevalence of abdominal obesity was 9.53% (95% CI = 9.12-9.95%) for boys and 9.82% (95% CI = 9.40-10.24%) for girls, no statistical differences between the two genders were observed (p > 0.05). In both boys and girls, the Z-scores of SBP and DBP were all significantly lower in group 1 than in group 2 (p < 0.01), indicating that children and adolescents with high WHR tended to have higher BP values.

CONCLUSION

WHR is useful in identifying children and adolescents at risk of developing high BP. These findings, together with the known tracking of BP from adolescence into adulthood, highlight the importance of preventing overweight and obesity among children and adolescents in order to prevent the development of hypertension in adults.

Dual burden of body weight among Iranian children and adolescents in 2003 and 2010: the CASPIAN-III study

INTRODUCTION

Our aim was to compare changes of body mass index (BMI) and waist circumference (WC) curves of Iranian children by comparing the results of two national surveys of a surveillance program, i.e. CASPIAN-I (2003-2004) and CASPIAN-III (2009-2010). The second objective was to evaluate the prevalence of obesity, overweight and underweight among 10-18-year-old Iranian children and adolescents.

MATERIAL AND METHODS

This study was performed among students who were selected by multistage random cluster sampling from urban and rural areas of 27 provinces of Iran, as part of a national survey of school student high risk behavior entitled CASPIAN-III, conducted in 2009-2010.

RESULTS

We evaluated 5088 school students (50.2% boys). In rural areas, underweight was more common in boys and overweight and obesity in girls. In urban areas underweight and obesity were more common in boys, whereas overweight was more common in girls. The highest prevalence of underweight (23.5%) was seen in students aged 13 years and the lowest (11.4%) in those aged 18 years. Underweight was significantly more common in rural than in urban areas (22.1% vs. 15.8%, respectively, p < 0.0001) and overweight/obesity was more common in urban than in rural areas. Compared with the findings in 2003-2004, the overall prevalence of elevated body mass index (16.6%) including obesity (9.1%) and overweight (7.5%) as well as underweight (17.5%) increased from 2003 to 2010.

CONCLUSIONS

In recent years, the double burden of nutritional disorders has increased among Iranian children and adolescents, especially in rural areas. This change may be related to epidemiologic transition, notably in terms of nutrition transition and rapid changes in lifestyle habits. This finding is an important issue for policy-makers for interventional preventive programs.