Waist-to-Height: Cutoff Matters in Predicting Metabolic Syndrome in Mexican Children

Correlation of body mass index and waist to height ratio with cardiovascular risk factors in Colombian preschool and school children

Objective

To analyze the agreement between body mass index (BMI) and waist-to-height Ratio (WHtR) to identify preschool and school children with cardiovascular risk factors (CRFs).

Methods

Three-hundred-twenty-one kids were divided into preschool (3-5 years) and school children (6-10 years). BMI was used to classify children as overweight or obese. Abdominal obesity was defined with a WHtR ≥0.50. Fasting blood lipids, glucose and insulin were measured, and the homeostasis model assessment of insulin resistance (HOMA-IR) was calculated. The presence of CRFs and multiple non-waist circumference (non-WC) metabolic syndrome factors (MetS-Factors) [high HOMA-IR, high triglycerides and low high-density lipoprotein cholesterol (HDL-C)] were analyzed.

Results

One-hundred-twelve preschool and 209 school children were evaluated. WHtR ≥0.50 classified abdominal obesity in more than half of the preschool children, exceeding those classified with overweight+obesity by BMI (59.5% vs. 9.8%; p<0.001). There was no agreement between WHtR and BMI to identify preschool kids with CRFs and multiple non-WC MetS-Factors (kappa: 0.0 to 0.23, p>0.05). There were similar proportions of school children classified with abdominal obesity by the WHtR and overweight+obesity by the BMI (18.7% vs. 24.9%; p>0.05). There was substantial agreement between WHtR and BMI to identify school children with high total cholesterol values, low-density lipoprotein cholesterol (LDL-C), triglycerides, non-HDL-C, insulin, HOMA-IR, low HDL-C values, and the presence of multiple non-WC MetS-Factors (kappa: 0.616 to 0.857, p<0.001).

Conclusion

In preschool children WHtR ≥0.5 disagree with BMI results, but in school kids, it has good agreement with the BMI to classify the children´s nutritional status and to identify those with CRFs.

Diagnostic test accuracy of waist-to-height ratio as a screening tool for cardiovascular risk in children and adolescents: a meta-analysis

CONTEXT

Waist-to-height ratio (WHtR) is a controversial evaluation index of cardiovascular risk factors (CVRFs) in children and adolescents.

OBJECTIVE

To assess the accuracy of WHtR as a measure to screen for clusters of at least one CVRF (CVRF₁), two CVRFs (CVRF₂), and three CVRFs (CVRF₃) in different ages, sexes, regions and cut-offs.

METHODS

The PubMed, Web of Science, EBSCOhost, Springer, Taylor & Francis Online, Wiley Online Library, Wanfang, and CNKI databases were searched for eligible publications up to June 2021. The QUADAS-2 checklist was used to assess the methodology of the included studies.

RESULTS

Twenty-two studies that evaluated 85281 children and adolescents aged 5-19 years were included in the meta-analysis. The AUSROC values were 0.56 (95% CI: 0.54-0.57), 0.82 (95% CI: 0.81-0.83), and 0.89 (95% CI: 0.89-0.90) for CVRF₁, CVRF₂, and CVRF₃, respectively. Higher AUSROC values were found for adolescents (12-19 years), that is, 0.91 (95% CI: 0.88-0.93), 0.90 (95% CI: 0.87-0.92) for males, and 0.91 (95% CI: 0.90-0.91) for a cut-off of ≥ 0.51 in the identification of CVRF₃.

CONCLUSION

WHtR can be used as an accurate screening tool for CVRF₃ and CVRF₂ in children and adolescents, and it is recommended to select different cut-offs according to different ages, sexes, and regions.

Diagnosis accuracy of waist-to-height ratio to predict cardiometabolic risk in children with obesity

BACKGROUND

Waist-to-height ratio (WHtR) predicts abdominal fat and cardiometabolic risk. In children with obesity, the most adequate cut-off to predict cardiometabolic risk as well as its ability to predict risk changes over time has not been tested. Our aim was to define an appropriate WHtR cut-off to predict cardiometabolic risk in children with obesity, and to analyze its ability to predict changes in cardiometabolic risk over time.

METHODS

This is an observational prospective study secondary to the OBEMAT2.0 trial. We included data from 218 participants (8-15 years) who attended baseline and final visits (12 months later). The main outcome measure was a cardiometabolic risk score derived from blood pressure, lipoproteins, and HOMA index of insulin resistance.

RESULTS

The optimal cut-off to predict the cardiometabolic risk score was WHtR ≥0.55 with an area under the curve of 0.675 (95% CI: 0.589-0.760) at baseline and 0.682 (95% CI: 0.585-0.779) at the final visit. Multivariate models for repeated measures showed that changes in cardiometabolic risk were significantly associated with changes in WHtR.

CONCLUSION

This study confirms the clinical utility of WHtR to predict changes in cardiometabolic risk over time in children with obesity. The most accurate cut-off to predict cardiometabolic risk in children with obesity was WHtR ≥0.55.

IMPACT

In children, there is no consensus on a unique WHtR cut-off to predict cardiometabolic risk. The present work provides sufficient evidence to support the use of the 0.55 boundary. We have a large sample of children with obesity, with whom we compared the previously proposed boundaries according to cardiometabolic risk, and we found the optimal WHtR cut-off to predict it. We also analyzed if a reduction in the WHtR was associated with an improvement in their cardiometabolic profile.

Accuracy of different cutoffs of the waist-to-height ratio as a screening tool for cardiometabolic risk in children and adolescents: A systematic review and meta-analysis of diagnostic test accuracy studies

The present systematic review with meta-analysis sought to estimate the accuracy of different waist-to-height ratio (WHtR) cutoff ranges as risk indicators for cardiometabolic health in different populations of children and adolescents. Systematic searches were undertaken to identify studies in apparently healthy participants aged 3-18 years that conducted receiver operating characteristic curve analysis and reported area under the receiver operating characteristic curves for WHtR with any cardiometabolic biomarker. Forty-one cross-sectional studies were included in the meta-analysis, including 138,561 young individuals (50% girls). Higher area under summary receiver operating characteristic (AUSROC) values were observed in cutoffs between 0.46 and 0.50 (AUSROC = 0.83, 95%CI: 0.80-0.86) and ≥0.51 (AUSROC = 0.87, 95%CI: 0.84-0.90) (p < 0.001 in comparison with cutoffs 0.41 to 0.45), with similar results in both sexes. The AUSROC value increased in the East and Southeast Asian regions using a WHtR cutoff of ≥0.46 (AUSROC = 0.90, 95%CI: 0.87 to 0.92). A cutoff of ≥0.54 was optimal for the Latin American region (AUSROC = 0.96, 95%CI: 0.94-0.97). Our meta-analysis identified optimal cutoff values of WHtR for use in children and adolescents from different regions. Despite the widely accepted WHtR cutoff of 0.50, the present study indicated that a single cutoff value of WHtR may be inappropriate.

Indicators of Obesity and Cardio-metabolic Risks: Important Consideration in Adults and Children

The prevalence of obesity has dramatically increased all over the world. Body mass index (BMI) has been used as the most common available measure to determining obesity status. While the site of excessive fat mass accumulation is a stronger determinant of cardio-metabolic complication, with respect to systemic and generalized obesity, which is only determined through BMI. So, it is concluded that using traditional anthropometric indices such as BMI for interpreting the obesity status and cardio-metabolic risk has considerable limitations. Thus, the main aims of the present study are to discuss possible drawbacks of anthropometric indices especially BMI, which in epidemiological studies are usually neglected, as well as lend important consideration to using other anthropometric indices such as measurement of obesity and related cardio-metabolic complications with a special emphasis on the use of waist circumference, waist-to-hip ratio and waist-to-height ratio.

Usefulness of the waist-to-height ratio for predicting cardiometabolic risk in children and its suggested boundary values

BACKGROUND & AIMS

Only limited information is available on the usefulness of the waist-to-height ratio (WHtR) as an abdominal obesity marker in children. Our aim was to compare the ability of a WHtR >90th percentile, a WHtR ≥0.50, a WHtR ≥0.55 and a BMI z-score ≥2 SD to predict cardiometabolic risk in children followed-up at different ages.

METHODS

We evaluated data from 660 children at 5, 8 and 11 years of age who participated in the Childhood Obesity Project trial in 5 European countries. We classified children with or without cardiometabolic (CMet) risk (yes vs. no) according to the presence of ≥2 parameters (blood pressure, HOMA-IR, triglyceride levels and high-density lipoprotein (HDL) cholesterol levels) ≥90th percentile.

RESULTS

The odds ratio for CMet risk in children at all followed-up ages was statistically significant for all measures. The OR for the WHtR≥0.55 cut-off was 29.1 (5.6, 151.7) at 5 years of age, 11.8 (4.1, 33.8) at 8 year of age and 3.6 (1.7, 7.7) at 11 years of age, compared to the WHtR<0.55 cut-off. The WHtR≥0.55 cut-off showed a higher OR at younger ages than the BMI z-score ≥2SD, WHtR ≥90th percentile and WHtR≥0.50 cut-offs and a higher positive predictive value (82% at 5 years of age compared to 55%, 36% and 41%, respectively).

CONCLUSION

A WHtR≥0.55 is a suitable cut-off for screening children at high cardiometabolic risk in the general young European population.

Waist-to-Height Ratio Is a Good Predictor of Metabolic Syndrome in Adolescents: A Report From the Thai National Health Examination Survey V, 2014

This study aimed to assess the performance of waist-to-height ratio (WHtR) in the prediction of metabolic syndrome and to determine the appropriate cutoff value in Thai adolescents. Demographic data, blood pressure, fasting blood glucose, and lipid profile were obtained from the Thai National Health Examination Survey V database. The performances of WHtR, waist circumference, body mass index (BMI), and BMI z-score were analyzed by the receiver operating characteristics. Among 2644 adolescents, metabolic syndrome was identified in 4.27%. The areas under the receiver operating characteristic curves of WHtR, waist circumference, BMI, and BMI z-score were comparable (0.924-0.960). Performance of WHtR was more constant across age groups compared with other parameters. Using the cutoff value of WHtR at 0.5 resulted in the sensitivity and specificity of 98.5%/83.4% and 88.9%/86.0% in males and females, respectively. In conclusion, the cutoff value of WHtR at 0.5 provided good sensitivity and specificity for identifying metabolic syndrome in both genders. However, the other clinical risk factors or more definite scores should be considered when further assessment.

Associations Between Single-Child Status and Metabolic Syndrome in Children and Adolescents in China

Objective: To evaluate the associations between single-child status and metabolic syndrome (MS) and to identify the highest risk group of MS among single children. Methods: Differences in participants' characteristics by sex were examined by Student's t-test for continuous variables and Pearson's chi-squared test for categorical variables. Multivariate logistic regression analysis was performed to estimate the odds ratios (OR) and 95% confidence intervals (CI) for MS and its components according to the single-child status. Radar maps were used to compare the composition of different components in MS. Results: In total, 11,784 (5,880 boys) children and adolescents were included in this study, with a mean age of (11.3 ± 3.1) years. MS was observed in 7.1% of participants, with a higher prevalence in boys (8.2%) than girls (5.9%) (P < 0.05). The prevalence of MS, elevated blood pressure and abdominal obesity in single children were higher than that in children with siblings, particularly in boys (P < 0.001). Elevated risk of abdominal obesity was observed in single children [boys (1.56, 95% CI: 1.31, 1.85), girls (1.40, 95% CI: 1.19, 1.63)], however, increased ORs of elevated blood pressure and metabolic syndrome were observed in single-child boys only (1.19, 95% CI: 1.01, 1.40 and 1.76, 95% CI: 1.34, 2.31, respectively). Results showed that a statistically significant association between single child status and MS was mainly observed in urban boys (2.04, 95% CI: 1.33, 3.12) and rural boys (1.50, 95% CI: 1.05, 2.15), but not in girls. Among all the combinations of MS, two combinations were significantly associated with the single-child status, including the combination of elevated blood pressure, abdominal and low HDL-C (1.45, 1.04, 2.04) and the combination of elevated blood pressure, abdominal obesity, low HDL-C and hypertriglyceridemia (2.04, 1.40, 3.06) (P < 0.05). Conclusions: The present study found that single children and adolescents had a higher risk of MS, elevated blood pressure and abdominal obesity. The associations were stronger in urban boys. Further attention should be directed to the prevention and control strategies targeting the high-risk population of MS.

Waist Circumference Is Not Associated with Impaired Fasting Blood Glucose in a Sample of Mexican Children and Teenagers: Results from a State Screening Program

A high waist circumference (WC) is used as a risk factor for impaired fasting blood glucose (IFG) in adults. This association is less studied in children and teenagers. The purpose of this study was to analyze the association between having a high WC and IFG by sex and age in a sample of Mexican children and teenagers. We analyzed the data of 12979 participants aged 5 to 17 years to calculate percentile references for uncorrected WC, corrected for height (WC/HT) and by height squared (WC/HT2) with quantile regression. A subsample of 2309 participants with fasting blood glucose samples (FBG), WC, WC/HT and WC/HT2 values was analyzed with logistic regression. A high WC, WC/HT, and WC/HT2 were considered at the sex- and age-specific 90th percentile from the subsample. The IFG was considered as FBG ≥100 mg/dL. Having a high WC, WC/HT, nor WC/HT2 was not significantly associated with IFG for either sex and age group (all p > 0.05). A high WC, either on its uncorrected or corrected for height values, was not an important assessment for predicting IFG in a sample of Mexican children and teenagers. This study provides percentile reference values specific for sex and age.

Tri-Ponderal Mass Index Reference Values for Screening Metabolic Syndrome in Children and Adolescents: Results From Two National-Representative Cross-Sectional Studies in China and America

INTRODUCTION

To ascertain the possible cut point of tri-ponderal mass index (TMI) in discriminating metabolic syndrome (MetS) and related cardio-metabolic risk factors in Chinese and American children and adolescents.

METHODS

A total of 57,201 Chinese children aged 7-18 recruited in 2012 and and 10,441 American children aged 12-18 from National Health and Nutrition Examination Survey (NHANES 2001-2014) were included to fit TMI percentiles. Participants were randomly assigned to a derivation set (75%) and validation set (25%). The cut points of TMI with the lowest misclassification rate under the premise of the highest area under curves (AUC) were selected for each sex, which were additionally examined in the validation set. All of data analysis was conducted between September and December in 2019.

RESULTS

TMI showed good capacity on discriminating MetS, with AUC of 0.7658 (95% CI: 0.7544-0.7770) to 0.8445 (95% CI: 0.8349-0.8537) in Chinese and 0.8871 (95% CI: 0.8663-0.9056) to 0.9329 (95% CI: 0.9166-0.9469) in American children. The optimal cut points were 14.46 kg/m³ and 13.91 kg/m³ for Chinese boys and girls, and 17.08 kg/m³ and 18.89 kg/m³ for American boys and girls, respectively. The corresponding misclassification rates were 17.1% (95% CI: 16.4-17.8) and 11.2% (95% CI: 9.9-12.6), respectively. Performance of these cut points were also examined in the validation set (sensitivity 67.7%, specificity 82.4% in Chinese; sensitivity 84.4%, specificity 88.7% in American children).

CONCLUSIONS

A sex- and ethnicity- specific single cut point of TMI could be used to distinguish MetS and elevated risk of cardio-metabolic factors in children and adolescents.

Identification of metabolic syndrome using phenotypes consisting of triglyceride levels with anthropometric indices in Korean adults

BACKGROUND

The metabolic syndrome (MetS) has shown strong associations with the hypertriglyceridemic waist (HW) phenotype. The best anthropometric indicator of MetS remains controversial. Furthermore, no studies have investigated alternative indices that could replace waist circumference in the HW phenotype. The objectives of this study were to find the best indicator of MetS among anthropometric indices and to examine the predictive power of phenotypes consisting of triglyceride levels with anthropometric indices.

METHODS

A total of 12,025 subjects participated in this retrospective cross-sectional study. All subjects were recruited between November 2016 and August 2007 from hospitals in 28 urban and rural regions in South Korea. The data analyzed in this study were obtained from the Korean Health and Genome Epidemiology Study database and the Korea Institute of Oriental Medicine.

RESULTS

The proportion of patients with MetS ranged from 9 to 57% according to age and gender groups. Waist circumference (WC) was best indicator of MetS in men of all age groups. However, in women aged 40-49 years, the waist-to-height ratio (WHtR) was the best indicator of MetS. Rib circumference and chest circumference were the strongest indicators in women aged 50-59 years and 70-79 years, respectively. The combination of WC and triglyceride (TG) was the best indicator of MetS in men and women overall. However, interestingly, the best indicator was TG + WHtR in women aged 40-49 years and TG + forehead-to-waist ratio in women aged 70-79 years.

CONCLUSIONS

The best indicator of MetS in terms of individual anthropometric indices and the various phenotypes combining a single anthropometric index with TG may differ subtly according to age group in women, but not in men. Our findings provide insight into a simple and inexpensive method that could be used to identify MetS in initial health screening efforts in epidemiology and public health.

Myokine-adipokine cross-talk: potential mechanisms for the association between plasma irisin and adipokines and cardiometabolic risk factors in Mexican children with obesity and the metabolic syndrome

BACKGROUND

Adipokines and the myokine irisin, involved in mechanisms associated with obesity and metabolic syndrome (MS), are understudied in the pediatric population.

OBJECTIVE

To investigate the relationship between irisin, and leptin, resistin, adiponectin, adipsin, anthropometric and cardiovascular risk factors in Mexican children.

METHODS

A cross-sample of 126 Mexican children aged 6-12 years old were classified as normal weight (n = 46), obese (n = 40), and MS (n = 40) according to CDC's and Cook's age-modified criteria for obesity and MS. Anthropometric parameters and blood pressure were determined and percentiles calculated for age and gender. Irisin, leptin, adiponectin, adipsin, resistin, triglycerides, glucose, high-density lipoprotein cholesterol (HDL-c) levels, and physical activity were determined. Statistical tests for differences between groups, correlation, and multiple regression analyses were performed.

RESULTS

Irisin plasma levels were significantly lower in the obese (6.08 [4.68-6.65]) and MS groups (6.46 [5.74-7.02]) compared with the normal-weight group (8.05 [7.24-8.94]) (p < 0.001). Irisin levels were not influenced by age or gender, but significant dispersion was observed in obese girls (95% CI median [2.29-6.30]). Leptin, resistin, and adipsin levels were significantly increased in the obese and MS groups. Lean-fat ratio was significantly higher in the NW group. Irisin correlated negatively with leptin (- 0.310), resistin (- 0.389), adipsin (- 0.362), BMI% (-0.472), WC% (- 0.453), BMI z-score (- 0.496), fat free mass (- 0.257), fat percentage (- 0.532), fat mass (- 0.515), triglycerides (- 0.291), the number of cardiometabolic risk factors (- 0.443) (p < 0.001); positively with lean-fat ratio (0.489) and HDL-c (0.328) (p < 0.001) and none with physical activity (p < 0.001). Following stepwise multiple linear regression analysis, the lean-fat ratio was the only determinant of irisin levels (B = 1.168, p < 0.001).

CONCLUSIONS

Lean-fat ratio, more than the absolute amount of muscle or fat mass, as well as potential myokine-adipokine cross-talk mechanisms may explain the lower irisin levels in children with obesity and MS, through blunted compensatory responses interfering with tissue-dependent irisin secretion, contributing to a continuous deleterious effect cycle.

Performance of Waist-To-Height Ratio, Waist Circumference, and Body Mass Index in Discriminating Cardio-Metabolic Risk Factors in a Sample of School-Aged Mexican Children

The most common tools used to screen for abdominal obesity are waist circumference (WC) and waist-to-height ratio (WHtR); the latter may represent a more suitable tool for the general non-professional population. The objective of this study was to evaluate the association of WHtR, WC, and body mass index with lipidic and non-lipidic cardio-metabolic risk factors and the prediction capability of each adiposity indicator in a sample of school-aged Mexican children. Overall, 125 children aged 6 to 12 years were analyzed. Anthropometric, biochemical, and dietary parameters were assessed. Receiving operating characteristic (ROC) analysis and univariate and multivariate linear and logistic regression analyses were performed. All the three adiposity indicators showed significant areas under the ROC curve (AURC) greater than 0.68 for high low-density lipoprotein cholesterol (LDL-c), triglycerides, and atherogenic index of plasma, and low high-density lipoprotein cholesterol (HDL-c). A significant increased risk of having LDL-c ≥ 3.4 mmol/L was observed among children with WHtR ≥ 0.5 as compared to those with WHtR < 0.5 (odds ratio, OR: 2.82; 95% confidence interval, CI: 0.75–7.68; p = 0.003). Fasting plasma glucose was not associated with any of the adiposity parameters. WHtR performed similarly to WC and z-BMI in predicting lipidic cardio-metabolic risk factors; however, a WHtR ≥ 0.5 was superior in detecting an increased risk of elevated LDL-c.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Probability and Body Composition of Metabolic Syndrome in Young Adults: Use of the Bayes Theorem as Diagnostic Evidence of the Waist-to-Height Ratio

Metabolic syndrome (MS) directly increases the risk of cardiovascular diseases. Childhood and adulthood have been the most studied in MS, leaving aside the young adult population. This study aimed to compare the epidemiological probabilities between MS and different anthropometric parameters of body composition. Using a cross-sectional study with the sample of 1351 young adults, different body composition parameters were obtained such as Waist Circumference (WC), Body Mass Index (BMI), Body Fat% (BF%), Waist-to-Height Ratio (WHtR), and Waist-Hip Ratio. The Bayes Theorem was applied to estimate the conditional probability that any subject developed MS with an altered anthropometric parameter of body composition. Areas under receiver operating characteristic curves (AUCs) and adjusted odds ratios of the five parameters were analyzed in their optimal cutoffs. The conditional probability of developing MS with an altered anthropometric parameter was 17% in WHtR, WC, and Waist-hip R. Furthermore, body composition parameters were adjusted by age, BMI, and gender. Only WHtR (OR = 9.43, CI = 3.4–26.13, p < 0.0001), and BF% (OR = 3.18, CI = 1.42–7.13, p = 0.005) were significant, and the sensitivity (84%) and the AUCs (86%) was higher in WHtR than other parameters. In young adults, the WHtR was the best predictor of metabolic syndrome.

Appropriate anthropometric indices of obesity and overweight for diagnosis of metabolic syndrome and its relationship with oxidative stress

AIMS

this study aimed to determine the most appropriate anthropometric indices for diagnosis of metabolic syndrome (MetS) and its relationship with oxidative stress markers.

MATERIAL AND METHODS

This cross-sectional study was conducted in 2015 on 108 employees working in Shahroud University of Medical Sciences. Demographics, anthropometric indices (BMI: Body mass index; WC: Waist circumference, WHR: Waist hip ratio, WHtR: Waist-to-height Ratio), Mets: and Then oxidative stress markers (total antioxidant capacity; TAC, Malondialdehyde; MDA, serum superoxide dismutase; SOD, catalase; Cat) were measured. All analyses were performed at a significant level of 0.05, using the SPSS Statistics 21 and Stata 12 software.

RESULT

The mean age of the participants was 41.4±7.8years. the mean values of different anthropometric indices in patients with metabolic syndrome were higher than those in subjects without MetS and this difference was significant. According to ROC curve the best marker for diagnosis of Mets was WHtR (Waist-to-height Ratio) and its cut off point was 0.54.Also, there was a positive correlation between WHtR and MDA serum levels. In addition, there was a negative correlation between WHtR and the levels of TAC, SOD, and CAT but it was not significant.

CONCLUSIONS

It seems that WHtR can be a valuable marker for predicting metabolic disorders and related diseases; moreover, it can be used for evaluation of oxidative stress level. Finally, the formula WC=height×0.54 as a simple tool for prevention of metabolic diseases can be used in university personnel.

ANTHROPOMETRY AND CLUSTERED CARDIOMETABOLIC RISK FACTORS IN YOUNG PEOPLE: A SYSTEMATIC REVIEW

OBJECTIVE

To conduct a systematic review of the literature on the ability of anthropometric indicators to predict clustered cardiometabolic risk factors (CMRF) in children and adolescents.

DATA SOURCE

Studies published from June 1st, 2011 to May 31st, 2016 in the PubMed, SciELO and LILACS databases were analyzed. The research was based on keywords derived from the terms "anthropometric indicators" AND "cardiometabolic risk factors". Observational studies on the ability of anthropometric indicators as predictors of clustered CMRF in children and adolescents in Portuguese, English and Spanish languages were included. Studies with a specific group of obese patients or with other diseases were not included.

DATA SYNTHESIS

Of the 2,755 articles retrieved, 31 were selected for systematic review. Twenty-eight studies analyzed body mass index (BMI) as a predictor of clustered CMRF. Only 3 of the 25 cross-sectional studies found no association between anthropometric indicators and clustered CMRF. The results of six studies that compared the predictive ability of different anthropometric measures for clustered CMRF were divergent, and it was not possible to define a single indicator as the best predictor of clustered CMRF. Only six articles were cohort studies, and the findings suggested that changes in adiposity during childhood predict alterations in the clustered CMRF in adolescence.

CONCLUSIONS

BMI, waist circumference and waist-to-height ratio were predictors of clustered CMRF in childhood and adolescence and exhibited a similar predictive ability for these outcomes. These findings suggest anthropometric indicators as an interesting screening tool of clustered CMRF at early ages.

Waist-to-height ratio, body mass index and waist circumference for screening paediatric cardio-metabolic risk factors: a meta-analysis

Waist-to-height ratio (WHtR) is superior to body mass index and waist circumference for measuring adult cardio-metabolic risk factors. However, there is no meta-analysis to evaluate its discriminatory power in children and adolescents. A meta-analysis was conducted using multiple databases, including Embase and Medline. Studies were included that utilized receiver-operating characteristics curve analysis and published area under the receiver-operating characteristics curves (AUC) for adiposity indicators with hyperglycaemia, elevated blood pressure, dyslipidemia, metabolic syndrome and other cardio-metabolic outcomes. Thirty-four studies met the inclusion criteria. AUC values were extracted and pooled using a random-effects model and were weighted using the inverse variance method. The mean AUC values for each index were greater than 0.6 for most outcomes including hypertension. The values were the highest when screening for metabolic syndrome (AUC > 0.8). WHtR did not have significantly better screening power than other two indexes in most outcomes, except for elevated triglycerides when compared with body mass index and high metabolic risk score when compared with waist circumference. Although not being superior in discriminatory power, WHtR is convenient in terms of measurement and interpretation, which is advantageous in practice and allows for the quick identification of children with cardio-metabolic risk factors at an early age.

Waist-to-height ratio as a screening tool for obesity and cardiometabolic risk

The waist-to-height ratio (WHtR), calculated by dividing the waist circumference (WC) by height, has recently gained attention as an anthropometric index for central adiposity. It is an easy-to-use and less age-dependent index to identify individuals with increased cardiometabolic risk. A WHtR cutoff of 0.5 can be used in different sex and ethnic groups and is generally accepted as a universal cutoff for central obesity in children (aged ≥6 years) and adults. However, the WHtR has not been validated in preschool children, and the routine use of WHtR in children under age 6 is not recommended. Prospective studies and meta-analysis in adults revealed that the WHtR is equivalent to or slightly better than WC and superior to body mass index (BMI) in predicting higher cardiometabolic risk. In children and adolescents, studies have shown that the WHtR is similar to both BMI and WC in identifying those at an increased cardiometabolic risk. Additional use of WHtR with BMI or WC may be helpful because WHtR considers both height and central obesity. WHtR may be preferred because of its simplicity and because it does not require sex- and age-dependent cutoffs; additionally, the simple message 'keep your WC to less than half your height' may be particularly useful. This review article summarizes recent publications on the usefulness of using WHtR especially when compared to BMI and WC as a screening tool for obesity and related cardiometabolic risks, and recommends the use of WHtR in clinical practice for obesity screening in children and adolescents.

Simplifying the screening of abdominal adiposity in Chinese children with waist-to-height ratio

OBJECTIVES

The current age- and sex-specific waist circumference (WC) reference for defining abdominal adiposity in Chinese children is quite complex. This study aimed to evaluate the optimal waist-to-height ratio (WHtR) thresholds based on the estimated WC references.

METHODS

A cross-sectional analysis of data from 121,025 Chinese children aged 7-18 years collected in 2010 was performed. Optimal WHtR thresholds were selected by Youden's index using receiver operating characteristic (ROC) curve analysis, with the estimated references of WC in Chinese children used as the gold standard.

RESULTS

The optimal cut-off values for identifying abdominally overweight and obese children were 0.44 and 0.46, respectively. Across the different sex and age groups, the proposed thresholds revealed high negative predictive values and areas under the ROC curve (≥0.857), and moderate to high sensitivity, specificity, and positive predictive values, ranging from 0.48 to 1.00.

CONCLUSIONS

The proposed WHtR thresholds reduce the number of cut-off values from 48 to 2, and have a high discriminatory ability to identify abdominal adiposity in Chinese children. Am. J. Hum. Biol. 28:945-949, 2016. © 2016Wiley Periodicals, Inc.

Association between Apolipoprotein E Variants and Obesity-Related Traits in Mexican School Children

BACKGROUND/AIM

Genetic variation in apolipoprotein E (ApoE) has a key role in lipid metabolism. However, its contribution to the amount and distribution of body fat is under investigation. The aim of this study was to analyze the association between genetic variation in ApoE and obesity-related traits in Mexican school children.

MATERIAL AND METHODS

Anthropometric, body composition and physical activity measures were conducted using standard methods in 300 children (177 girls/123 boys) who fulfilled the inclusion criteria. DNA was isolated from saliva. ApoE genotypes were analyzed by allelic discrimination. The association between variation in ApoE and anthropometric and body composition measures was investigated using the General Linear Model.

RESULTS

The mean±SD values for age, body mass index (BMI) and waist circumference (WC) were 9.05±0.80 years, 19.01±3.83 and 67.98±10.97 cm, respectively. Approximately 46% of the participants were overweight or obese. A significant association between ApoE isoforms and WC was found after controlling for age, sex and the percentage of physical activity (p=0.025). Significant main effects were found for vigorous physical activity and light physical activity influencing the adiposity-related BMI (p<0.001) and WC (p=0.044), respectively.

CONCLUSIONS

Variation in ApoE and physical activity intensity were associated with adiposity-related phenotypes in Mexican school children.

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.

Waist-to-Height Ratio: a simple, effective and practical screening tool for childhood obesity and metabolic syndrome

OBJECTIVE

This study aimed to evaluate the diagnostic value of Waist-to-Height Ratio in early detection of obesity and metabolic syndrome in Chinese children and adolescents.

METHOD

A cross-sectional study was conducted in six cities in China in 2010 with 16,914 children and adolescents aged 7-17 years. Participants were randomly divided into the training and testing sets. Diagnostic values were estimated using sensitivity, specificity and areas under receiver operating characteristic curves.

RESULTS

The coefficients of variation of Waist-to-Height Ratio among age groups were lower than that of body mass index and waist circumstance. The area under receiver operating characteristic curve of Waist-to-Height Ratio was 0.968 in boys and 0.949 in girls for general obesity evaluation, and 0.983 in boys and 0.984 in girls for central obesity. The optimal cut-offs of Waist-to-Height Ratio were 0.47 in boys and 0.45 in girls in the training set and validated in the testing set. For metabolic syndrome evaluation, the sensitivity and specificity were 0.858 and 0.825 in boys, 0.864 and 0.812 in girls under the suggested cut-offs.

CONCLUSION

Waist-to-Height Ratio was a simple, effective and practical tool for mass screening childhood obesity and metabolic syndrome in China. It will have potential values in public health practice.

Utility of the waist-to-height ratio, waist circumference and body mass index in the screening of metabolic syndrome in adult patients with type 1 diabetes mellitus

BACKGROUND

The incidence of macrovascular complications and morbidities associated to metabolic syndrome are increasing in patients with type 1 diabetes mellitus (T1DM). The combination of T1DM with features of insulin resistance similar to that of type 2 diabetes (T2DM), sometimes called "double diabetes", has been associated with central obesity. Since the most methods to accurately detect body fat and insulin resistance are not readily available, we propose that certain indirect indexes for detecting obesity as waist-to-height ratio, waist circumference and body mass index, may be useful when screening for metabolic syndrome in patients with T1DM.

METHODS

We performed a transversal evaluation (clinical and biochemical) in all the patients of the T1DM Clinic (n = 120). We determined the presence of metabolic syndrome according to the Joint Statement Criteria by the American Heart Association/ National Heart Lung and Blood Institute and the International Diabetes Federation and the utility of certain anthropometric indexes for predicting double diabetes was evaluated.

RESULTS

Thirty seven percent of the patients were considered to have metabolic syndrome using these criteria (n = 30). These patients were significantly older (p = 0.002), have a higher glycated hemoglobin (p = 0.036), cholesterol (p < 0.012) and triglyceride concentration (p < 0.01) as well as body mass index (p = 0.004), waist circumference (p = 0.01) and waist-to-height ratio (p < 0.01) than the group without metabolic syndrome. Also their c-HDL is lower (p < 0.01). A value of 0.52 for waist-to-height ratio correctly classified the largest number of patients (68% of correctly classified) well as the waist circumference (66% of correctly classified) with an adequate specificity and sensibility. Meanwhile the most precise body mass index value only classified correctly to 61% of patients.

CONCLUSION

Our data show that waist circumference and waist-to-height ratio indexes are useful to predict the presence of metabolic syndrome in adult patients with type 1 diabetes mellitus.

Prevalence of abdominal obesity in Spanish children and adolescents. Do we need waist circumference measurements in pediatric practice?

Background

Evidence indicates that central adiposity has increased to a higher degree than general adiposity in children and adolescents in recent decades. However, waist circumference is not a routine measurement in clinical practice.

Objective

This study aimed to determine the prevalence of abdominal obesity based on waist circumferences (WC) and waist to height ratio (WHtR) in Spanish children and adolescents aged 6 to 17 years. Further, the prevalence of abdominal obesity (AO) among normal and overweight individuals was analyzed.

Design

Data were obtained from a study conducted from 1998 to 2000 in a representative national sample of 1521 children and adolescents aged 6 to 17 years (50.0% female) in Spain. WC and WHtR measurements were obtained in addition to BMI. AO was defined as WHtR ≥0.50 (WHtR-AO), sex and age specific WC≥90^th percentile (WC-AO1), and sex and age specific WC cut-off values associated with high trunk fat measured by by dual-energy X-ray absorptiometry (WC-AO2).

Results

IOTF- based overweight and obsity prevalence was 21.5% and 6.6% in children and 17.4% and 5.2% in adolescents, respectively. Abdominal obesity (AO) was defined as WHtR≥0.50 (WHtR-AO), sex- and age-specific WC≥90th percentile (WC-AO1), and sex- and age-specific WC cut-off values associated with high trunk fat measured by dual-energy X-ray absorptiometry (WC-AO2). The respective prevalence of WHtR-AO, WC-AO1, and WC-AO2 was 21.3% (24.6% boys; 17.9% girls), 9.4% (9.1% boys; 9.7% girls), and 26.8% (30.6% boys;22.9% girls) in children and 14.3% (20.0% boys; 8.7% girls), 9.6% (9.8% boys; 9.5% girls), and 21.1% (28.8% boys; 13.7% girls) in adolescents.

Conclusion

The prevalence of AO in Spanish children and adolescents is of concern. The high proportion of AO observed in young patients who are normal weight or overweight indicates a need to include waist circumference measurements in routine clinical practice.

Waist-to-Height Ratio Is a Better Anthropometric Index than Waist Circumference and BMI in Predicting Metabolic Syndrome among Obese Mexican Adolescents

Objective. To identify the degree of association between anthropometric indices and components of metabolic syndrome (MS) and to determine optimal cut-off points of these indices for predicting MS in obese adolescents. Methods. A cross-sectional study with a sample of (n = 110) Mexican obese adolescents grouped by sex and the presence/absence of MS. BMI percentile, waist circumference (WC), and waist-to-height ratio (WHtR) were tested. ROC curves of the anthropometric indices were created to identify whether an index was a significant predictor of MS. Results. BMI percentile, WC, and WHtR were significantly correlated with systolic and diastolic blood pressure. As predictors of MS overall patients, the BMI percentile generated an area under curve (AUC) of 0.651 (P = 0.008), cut-off point above the 99th percentile. WC generated an AUC of 0.704 (P < 0.001), cut-off point of ≥90 cm. WHtR demonstrated an AUC of 0.652 (P = 0.008), cut-off point of 0.60. WHtR ≥0.62 and WHtR ≥0.61 generate AUC of 0.737 (P = 0.006) and AUC of 0.717 (P = 0.014) for predicting hypertension and insulin resistance, respectively, in females. Conclusion. WHtR is a better tool than WC and BMI for identifying cardiometabolic risk. The overall criterion (WHtR ≥ 0.6) could be appropriate for predicting MS in obese Mexican adolescents.

Novel noninvasive anthropometric measure in preterm and full-term infants: normative values for waist circumference:length ratio at birth

BACKGROUND

Waist circumference:length ratio (WLR) and ponderal index (PI) appear to be useful markers of visceral and total adiposity, respectively. However, there are no normative birth data across the full range of gestational ages.

METHODS

In this retrospective cohort study of 500 preterm and 1,426 full-term infants, born in 1998 and 2008 at three military hospitals, the percentile growth curves for WLR and PI were calculated. There were no sex differences, and results were combined to obtain values from 26 to 42 wk gestation.

RESULTS

Between 26 and 42 wk gestation, median birth WLR increased from 0.55 to 0.62, and median PI increased from 21.1 to 25.6. The adjusted mean WLR at birth among infants born <34 wk increased from 0.55 in 1998 to 0.58 in 2008 (P = 0.048), suggesting that early-preterm infants born in 2008 had greater abdominal adiposity than those born in 1998.

CONCLUSION

We report normative birth data for WLR and PI in preterm and full-term infants by gestational age and sex. WLR and PI may be useful as clinical markers of visceral and overall adiposity. In conjunction with other anthropometric measures, WLR and PI may be useful to monitor postnatal nutrition and growth and assess risk for later obesity and cardiometabolic disorders.

Is central obesity associated with poorer health and health-related quality of life in primary school children? Cross-sectional results from the Baden-Württemberg Study

BACKGROUND

Childhood obesity and its consequences are a growing threat to national economies and health services. The aim of this study was to determine associations between waist-to-height ratio (WHtR) as a measure of central obesity, and health-related quality of life (HRQoL) and absenteeism of primary school children in the state of Baden-Württemberg, Germany.

METHODS

Cross-sectional data from 1888 first and second grade children (7.1±0.6 years) participating in the baseline measurements of the Baden-Württemberg Study were analyzed. Parents completed questionnaires including a rating of their children's HRQoL using KINDLR and EQ5D-Y VAS. Days of absence because of illness, and number of visits to a physician during the last year of school/kindergarten were asked, as well as the number of days parents took off work to care for their sick child. Anthropometric measurements were taken by trained staff. The Mann-Whitney-U test was used for statistical analysis of differences between WHtR groups. Logistic regression models were used to identify factors associated with sick days.

RESULTS

A total of 158 (8.4%) children were centrally obese (WHtR ≥0.5). These children had significantly more sick days (9.05 vs. 6.84, p < 0.001) and visits to a physician (3.58 vs. 2.91, p < 0.05), but not days of parental absence than other children. According to regression analysis, sick days were also associated with age, migration status, physical activity pattern, maternal health awareness and family education level. Parent-rated HRQoL was significantly lower in centrally obese children for the EQ5D-Y VAS (88.1 vs. 91.6, p < 0.001), and the KINDLR subscales 'school' (79.9 vs. 82.5, p < 0.05) and 'friends' (75.4 vs. 78.3, p < 0.05), but not for the total score.

CONCLUSIONS

Cross-sectional results show higher rates of absence, more visits to a physician and lower HRQoL in children with central obesity. Each missed day at school implies a hazard to academic achievement and each additional visit to a physician is related to higher health care costs. Thus, the negative impact of central obesity is already measurable in primary school children, which emphasizes the urgent need for early delivery of health promotion and targeted prevention.

Metabolic syndrome and its components among obese (BMI >=95th) Mexican adolescents

The aim of this study was to estimate the prevalence of metabolic syndrome (MS) and its components in obese Mexican adolescents and to compare the clinical, anthropometric, and biochemical characteristics between patients with and without MS by sex. We conducted a cross-sectional study with a sample of 110 obese adolescents (boys and girls) from 8 to 16 years old (BMI ≥95th percentile), who were recruited in the pediatric obesity clinic of a third-level care hospital. A frequency analysis was used to estimate the prevalence of MS and its components, and the assessments were compared between the sexes and between the groups with and without MS using the Kruskal-Wallis test. The prevalence of MS was 62%. IN ORDER OF PREVALENCE, THE FOLLOWING COMPONENTS OF MS WERE OBSERVED IN THE SAMPLE: abdominal obesity (88%), high triglycerides (TG) (85%), low HDL-C (60%), hypertension (35%), and hyperglycemia (5%). In the groups with MS, hypertension (P<0.001), waist circumference (P=0.003), and TG (P=0.012) were significantly higher, and HDL-C (P<0.001) was significantly lower. In conclusion the prevalence of MS and its components is high among obese Mexican-Hispanic children. These findings show the importance of preventing and treating obesity in the early stages of life in order to decrease the incidence rates of cardiovascular disease and type 2 diabetes mellitus.

Indices of abdominal adiposity and cardiorespiratory fitness test performance in middle-school students

BACKGROUND

Previous research suggests that use of BMI as a screening tool to assess health in youth has limitations. Valid alternative measures to assess body composition are needed to accurately identify children who are aerobically fit, which is an indicator of health status. The purpose of this study was to examine the associations between select anthropometric measures and cardiorespiratory fitness test performance in middle-school students.

METHODS

Participants included 134 students (65 boys and 69 girls) recruited from the 6th, 7th, and 8th grades. Anthropometric measures consisted of BMI, waist circumference (WC), waist-to-height ratio (WHtR), and percent body fat estimated from two-site skinfolds (%BF-SKF), as well as the hand-held OMRON BIA device (%BF-BIA). Cardiorespiratory fitness tests included the one-mile run and PACER test. Data were collected on four separate testing days during the students' physical education classes.

RESULTS

There were statistically significant moderate correlations between the %BF estimations, WHtR, and cardiorespiratory fitness test scores in both genders (P < .001). BMI at best only displayed weak correlations with the cardiorespiratory fitness test scores.

CONCLUSIONS

The results suggest that alternative measures such as %BF-SKF, %BF-BIA, and WHtR may be more valid indicators of youth aerobic fitness lending to their preferred use over BMI.

Preterm infants of lower gestational age at birth have greater waist circumference-length ratio and ponderal index at term age than preterm infants of higher gestational ages

OBJECTIVE

To assess anthropometric changes from birth to hospital discharge in infants born preterm and compare with a reference birth cohort of infants born full-term.

STUDY DESIGN

Retrospective chart review was conducted of 501 preterm and 1423 full-term infants. We evaluated birth and hospital discharge weight, length, and waist circumference (WC). WC/length ratio (WLR), ponderal index, and body mass index (BMI) were calculated. Preterm infants were categorized into quartiles (Q1-4) based on birth weight (BW).

RESULTS

At birth mean length, WC, WLR, BMI, and ponderal index were all significantly less for preterm infants in the lowest BW quartile (Q1) than preterm infants in higher BW quartiles or full-term infants. Although their weight, length, and BMI remained significantly less at discharge, preterm infants in Q1 had a disproportionate increase in WLR and ponderal index such that at discharge their WLR and ponderal index were greater than infants in Q2-3 and comparable with infants in Q4 and full-term infants. Discharge WLR and ponderal index in Q1 were significantly higher with decreasing postmenstrual age at birth.

CONCLUSIONS

Preterm infants of a lower birth postmenstrual age have disproportionate increases in WLR and ponderal index that are suggestive of increased visceral and total adiposity.