Associations between adiposity indicators and elevated blood pressure among Chinese children and adolescents

Waist-to-height-ratio is associated with sustained hypertension in children and adolescents with high office blood pressure

Background

Waist-to-height-ratio (WHtR) has been proposed as another indicator for cardiometabolic risk factors including hypertension. Normally, hypertension can be diagnosed in the office setting by detecting high blood pressure for three occasions. However, patients with high office blood pressure may not exhibit high blood pressure outside the office. Ambulatory blood pressure monitoring (ABPM) is a procedure to measure blood pressure over 24-h. Sustained hypertension is characterized as hypertension detected by both office measurement and ABPM. This study aimed to evaluate the performance of WHtR in the diagnosis of sustained hypertension in patients with high office blood pressure.

Materials and methods

Demographic data, height, body weight, body mass index (BMI), and waist circumference were retrospectively reviewed in children and adolescents who underwent ABPM due to persistently high office blood pressure. Patients were separated into two groups: a sustained hypertension group and a normal ABPM group. BMI was adjusted to z-score using the WHO Anthroplus software. WHtR was calculated by the formula: waist circumference (cm)/height (m). The performances of different parameters were analyzed using the receiver operating characteristic (ROC) curve and multivariate logistic regression.

Results

Sixty patients (63% male) with a mean age of 12.9 ± 3.7 years had persistently high office blood pressure. Twenty-nine (48.3%) had high ambulatory blood pressure parameters so-called "sustained hypertension." The sustained hypertension group had a higher mean BMI z-score (2.32 vs. 1.31, p = 0.01) and a higher mean WHtR (57.7 vs. 49.2 cm/m, p < 0.001) than those of the normal ABPM group. For the diagnosis of sustained hypertension, the ROC analysis revealed that WHtR had a greater area under the ROC curve (AUC) than that of BMI z-score (0.772 vs. 0.723). WHtR remained associated with sustained hypertension (OR 1.2, 95% CI 1.022-1.408, p = 0.026) after adjusting for age, gender, and BMI z-score.

Conclusions

Apart from being a more user-friendly metric, WHtR tended to outperform BMI z-score in predicting sustained hypertension in children and adolescents with persistently high office blood pressure.

Association of waist circumference with blood pressure and familial dietary habits in preschool children: a cross-sectional study in northeastern China

Background

Childhood obesity increases the risk of elevated blood pressure (BP) in children. Body mass index (BMI), waist circumference (WC) and waist-to-height ratio (WHtR) are traditional obesity indices, but the extent to which these indices are associated with elevated BP in childhood remains debatable. Moreover, the familial dietary environment plays an important role in obesity, so it is necessary to determine the most relevant dietary factors for childhood obesity to prevent elevated BP. Our study aimed to identify the obesity indices that are most closely associated with elevated BP and then to determine the independent familial dietary factors for those obesity indices.

Method

A total of 605 children aged 2 to 6 years, as well as their parents, were involved in this study. The weight, height, WC and BP of the children were measured. Information on familial environments was obtained by questionnaires completed by the parents. BMI, WC and WHtR were standardized into z scores, and categorical variables of these three obesity indices were defined as BMI Category, WC Category and WHtR Category. Logistic regression was used to analyse the associations between all obesity indices and elevated BP. Multivariate linear regression and logistic regression were used to determine the independent factors for obesity indices.

Results

The obesity indices that were most closely associated with elevated BP were WC and WC Category. Parental BMI, birth weight, eating wheat as a staple food, appetite, eating speed, snacking while watching TV, parental encouragement to eat a diverse assortment of foods and drinking milk were independently associated with WC in both males and females. The risk of abdominal obesity increased 1.375 times in males and 1.631 times in females if appetite increased one level. If eating speed increased one level, the risk of abdominal obesity increased 1.165 times in males and 0.905 times in females. Females who drank milk more than 6 times per week had a 0.546 times lower risk of abdominal obesity.

Conclusion

WC was an anthropometric parameter more closely associated with elevated BP. In addition to genetics, some familial dietary factors involving eating preference, eating habits and parental feeding practice were independently associated with WC and abdominal obesity in preschool children.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13052-022-01236-3.

Diagnostic accuracy of anthropometric indices for discriminating elevated blood pressure in pediatric population: a systematic review and a meta-analysis

BACKGROUND

Childhood obesity is more likely to increase the chance of many adult health problems. Numerous studies have shown obese children to be more prone to elevated blood pressure (BP) and hypertension. It is important to identify an obesity anthropometric index with good discriminatory power for them in pediatric population.

METHODS

MEDLINE/PubMed, Web of Science, and Cochrane databases were retrieved comprehensively for eligible studies on childhood obesity and hypertension/elevated BP through June 2021. The systematic review and meta-analysis of studies used receiver operating characteristics (ROC) curves for evaluating the discriminatory power of body mass index (BMI), waist circumference (WC), and waist-to-height ratio (WHtR) in distinguishing children with elevated BP and hypertension.

RESULTS

21 cross-sectional studies involving 177,943 children and 3-19 years of age were included in our study. Meta-analysis showed that the pooled area under the reporting receiver-operating characteristic curves (AUC) and 95% confidence intervals (CIs) for BMI, WC, and WHtR to detect hypertension of boys were 0.68 (0.64, 0.72), 0.69 (0.64, 0.74), 0.67 (0.63, 0.71), for elevated BP, the pooled AUCs and 95% CIs were 0.67 (0.61, 0.73), 0.65 (0.58, 0.73), 0.65 (0.61, 0.71). The pooled AUCs and 95% CIs for BMI, WC and WHtR of predicting hypertension were 0.70 (0.66, 0.75), 0.69 (0.64, 0.75), 0.67 (0.63, 0.72) in girls, the pooled AUCs and 95% CIs of predicting elevated BP were 0.63 (0.61, 0.65), 0.62 (0.60, 0.65), 0.62 (0.60, 0.64) respectively. There was no anthropometric index was statistically superior in identifying hypertension and elevated BP, however, the accuracy of BMI predicting hypertension was significantly higher than elevated BP in girls (P < 0.05). The subgroup analysis for the comparison of BMI, WC and WHtR was performed, no significant difference in predicting hypertension and elevated BP in pediatric population.

CONCLUSIONS

This systematic review showed that no anthropometric index was superior in identifying hypertension and elevated BP in pediatric population. While compared with predicting elevated BP, all the indicators showed superiority in predicting hypertension in children, the difference was especially obvious in girls. A better anthropometric index should be explored to predict children's early blood pressure abnormalities.

Risk factors involved in adolescent obesity: an integrative review

The scope of this study was to examine the risk factors for the development of obesity in adolescence. The objective was to identify risk factors for adolescent obesity by means of an Integrative Review of the Literature. The PICO strategy was used to formulate the following central line of inquiry: What are the risk factors for the development of obesity during adolescence? The VHL and EBSCOhost research databases were consulted, resulting in a selection of 25 articles for in-depth study. The phenomenon of obesity was understood as the result of biological, social, psychological, and nutritional factors. The research revealed a lack of consensus on the risks and benefits, which makes evidence-based recommendations difficult. The study identified proposals that can be implemented, such as a change in eating habits, weight control and the practice of physical exercise. Such behavioral changes can be recommended within the context of the family, schools, and health services. The review recommends prevention strategies and the recognition of school as the ideal medium for health promotion through education. From a political and social standpoint, it is necessary to challenge the prevalence of publicity of the food industry that entices adolescents to consume processed foods with high fat and sugar content.

Diagnostic Precision of Anthropometric Variables for the Detection of Hypertension in Children and Adolescents

Introduction: High blood pressure (HBP) is a health problem the prevalence of which has increased in young populations. Overweight and obesity in early ages have been directly related to its development. Due to the impact of HBP, it is necessary to provide tools that facilitate its early diagnosis, with useful anthropometric variables being those that assess obesity. The objective of this paper was to determine the diagnostic accuracy of anthropometric variables to detect HBP. Methods: A cross-sectional study was conducted on 265 students aged 6-16. The diagnosis of HBP was made following the criteria proposed by the Spanish Association of Pediatrics. Through different statistical methods, the association between anthropometric variables of general obesity with HBP was analyzed. Results: Waist circumference (WC) showed the best diagnostic capacity (area under the receiver operating characteristic curve = 0.729), with a sensitivity and specificity of 72.2% and 76%, respectively, for a cut-off point of 73.5 cm. In the adjusted multivariate analysis, an association was found between HBP and anthropometric variables: WC (odds ratio (OR) = 10.7), body mass index (OR = 7.5), waist-to-height ratio (OR = 5.5) and body fat percentage (OR = 5.3) (p < 0.05). Conclusions: The anthropometric variables studied showed a moderate predictive capacity for HBP, highlighting WC, which showed the strongest association with HBP in the infant and child population.

The utility of anthopometric indicators to identify cardiovascular risk factors in Vietnamese children

BMI, waist circumference (WC) and waist-to-height ratio (WHtR) can be used for discriminating children and adolescents at risk of CVD. However, consensus on how to use these anthropometric indicators is lacking for children and adolescents in Asia. Discrete criteria are promoted internationally, but continuous variables could be used. Data from a survey of 10 949 Vietnamese school-aged children (6-18 years) were used to evaluate the performance of anthropometric indicators to identify elevated blood pressure (BP), dyslipidaemia or at least three cardiovascular risk factors (CVRF). Weight, height, WC and BP were measured using standardised protocols; 1009 participants who had blood lipids were analysed. AUC was used to assess the performance, and the Youden index to identify optimal cut-offs. The prevalence of elevated BP, dyslipidaemia and CVRF was 26·5, 49·3 and 12·2 %, respectively. BMI, WC and WHtR had low capacity to identify elevated BP and dyslipidaemia (AUC range 0·61-0·66) but moderate capacity to identify CVRF (0·72-0·74). Optimal BMIZ cut-offs to identify elevated BP, dyslipidaemia and CVRF were 0·40, 1·01 and 1·1 sd; for WC z-score, they were 0·06, 0·49 and 0·62 sd; for WHtR, optimal cut-offs were close to 0·5. A BMIZ cut-off of 1·0 sd and a WHtR cut-off of 0·5 would, therefore, be useful criteria to identify Vietnamese children who are likely to have CVRF. However, further validation of these criteria in other studies of Asian children and adolescents is needed.

Comparison of child adiposity indices in prediction of hypertension in early adulthood

We aimed to compare child body mass index (BMI) in prediction of hypertension in early adulthood with 4 other adiposity indices (waist circumference [WC], waist circumference-to-height ratio [WHtR], waist-to-hip ratio [WHR], and triceps skinfold [TSF]). The cohort from the China Health and Nutrition Survey 1993-2011 consisted of 1444 adults aged 18-36 years who were examined in childhood and early adulthood. Child adiposity indices and adult blood pressure (BP) were transformed into age-, sex-, and survey year-specific Z-scores. Adult hypertension was defined as BP ≥130/80 mm Hg as per the 2017 American College of Cardiology/American Heart Association guidelines. Adult hypertension prevalence was 32.9% during a mean follow-up of 10.1 years. Childhood BMI showed stronger correlation with adult BP than WHR and TSF (PS for difference <.05). Child BMI showed the better prediction of adult hypertension compared with WHtR, WHR, and TSF using area under the receiver operating characteristic curves (PS for difference <.05). Per SD change in the predictor, child BMI (relative risk [95% confidence interval], 1.11 [1.04-1.18]) and WC (1.12 [1.05-1.20]) were significantly associated with adult hypertension using covariate-adjusted Poisson models with robust standard errors. Child BMI performed equally or better compared with 4 other adiposity indices in predicting adult hypertension.

Associations between body mass index, waist circumference, waist-to-height ratio, and high blood pressure among adolescents: a cross-sectional study

The purpose of the present study was to examine the associations between body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR), and high blood pressure (HBP), and to determine which anthropometric parameters can best predict HBP among Lithuanian adolescents aged 12–15 years. Data from the survey of “Prevalence and Risk Factors of HBP in 12–15-Year-Old Lithuanian Children and Adolescents (Study 1, 2010–2012)” were used; a total of 7,457 respondents (3,494 boys and 3,963 girls) were included in this analysis. Adolescents with BP above the 90th percentile were measured on two different occasions. Logistic regression analysis was used to assess the associations and to calculate odds ratios. Receiver operating characteristic (ROC) curve analysis was used to evaluate the predictive ability of the three anthropometric parameters to predict HBP. The adjusted odds ratios (aOR) in the highest quartiles of BMI, WC, and WHtR were statistically significant for both sexes separately (reference group – the first quartile): in boys, prehypertension – 4.91, 4.09, and 1.59; hypertension – 7.96, 6.44, and 2.81; and prehypertension/hypertension – 6.85, 5.65, and 2.37, respectively; and in girls, prehypertension – 3.42, 2.70, and 1.66; hypertension – 5.71, 3.54, and 2.90; and prehypertension/hypertension – 4.62, 3.17, and 2.31, respectively). According to the analyses of the ROC curve, BMI z-score provided the largest area under the curve (AUC) value, followed by WC z-score, while WHtR z-score showed the lowest AUC value in predicting elevated BP in both sexes separately. Among Lithuanian adolescents aged 12–15 years, both anthropometric indices – BMI and WC (but particularly BMI) – showed stronger associations with HBP and were better for the prediction of HBP, compared to WHtR.

High blood pressure screening in children and adolescents from Amargosa, Bahia: usefulness of anthropometric indices of obesity

OBJECTIVE

To determine the predictive power of body mass index (BMI), waist circumference (WC), and waist-to-height ratio (WHtR), and their respective cut-off points for high blood pressure (BP) screening in Brazilian children and adolescents.

METHOD

Cross-sectional study conducted with 1,139 students aged 6 to 17years. Body weight, height, WC, and BP were measured. High BP was classified as systolic or diastolic ≥ 95th percentile. Receiver Operating Characteristic (ROC) curves were constructed, and the area under the curve, sensitivity, and specificity were calculated.

RESULTS

The prevalence of high BP was 27.0%. Anthropometric indices showed a significant association with high BP (accuracy ranging from 0.62 - 0.81), except for WHtR among male adolescents.Sensitivity was low, regardless of the anthropometric index, gender, and age group.

CONCLUSION

BMI, WC, and WHtR were associated with high BP, but the cut-off points tested showed low sensitivity. Determining specific cut-off points for each population can enable the use of anthropometric indices in high BP screening.

Blood Pressure, Heart Rate Variability, and Adiposity in Caribbean Pre-pubertal Children

Childhood obesity prevalence has increased over the last 30 years. The Heart Rate Variability (HRV) studies performed in adults suggest a possible relation between abnormal autonomic regulation and hypertension in the situation of overweight or obesity. Objective: The aims of this study were to explore the early relationships between adiposity and blood pressure and HRV in pre-pubertal children. Methods: Data were collected during the medical examination of the follow-up at 7 years of the TIMOUN mother-child cohort in Guadeloupe. Body Mass Index z-score (zBMI), sum of tricipital and subscapular skinfold thickness, percentage of fat mass, and Waist-to-Height Ratio were measured. A global corpulence score was computed using a Principal Component Analysis (PCA). Systolic Blood Pressure (SBP) and HRV parameters (cardiac holter monitoring) were collected under 2 conditions (calm and tachycardial period). Relations between HRV, SBP, each adiposity indicator and the corpulence score were studied with restricted cubic splines models, and linear regression models. The age at adiposity rebound (AR) was estimated from the individual growth curves. Results: 575 children were included in the SBP study (mean age: 7.7 years, from 85 to 99 months). SBP was linearly correlated with the corpulence score and the zBMI. An increase of 1 in the zBMI was associated with an increase of 2.3 (±0.28) mmHg in SBP. The effect-size of zBMI on SBP was higher in children with early age at AR. Compared to children with normal BMI, children with a zBMI <™2SD had their RMSSD, SDNN, LF and HF indicators in tachycardial conditions significantly reduced by -30, -21, -37, and -48%, respectively. In boys with a zBMI >2SD, we observed a global increase in all HRV parameters (under tachycardial conditions), particularly the LF [β = 0.43 (±0.18)]. Conclusion: In pre-pubertal period a positive correlation between adiposity excess and SBP was observed with significant changes of HRV in boys, arguing for an early abnormal autonomic regulation and for early preventive intervention in the infancy period, particularly in case of overweight or obesity. Thinness was associated with a reduction in almost all the HRV parameters studied, when compared to normal corpulence, suggesting a decrease in autonomic influence.

Associations of anthropometric adiposity indexes with hypertension risk: A systematic review and meta-analysis including PURE-China

BACKGROUND AND OBJECTIVE

The association between hypertension and obesity has been confirmed, while no agreement has been reached about which anthropometric adiposity index is the best. This meta-analysis aimed to perform a systematic review and meta-analysis on the associations of hypertension risk with body mass index (BMI), waist circumstance (WC), waist-to-hip ratio (WHR), and waist-to-height ratio (WHtR), and a prospective urban and rural epidemiology study from China (PURE-China) was added into this meta-analysis as an individual study.

METHODS

Systematic literature searching was conducted to identify relevant articles published up to September 2018 in CNKI, WANFANG Data, Web of Science, SinoMed, PubMed, MEDLINE, EMBASE, Cochrane Library and cross-referencing. Literature reporting the association of hypertension risk with BMI, WC, WHR, and WHtR were defined as eligible. PURE-China data were analyzed and included as 1 eligible study into meta-analyses. Summary odds ratio (OR) and area under receiver operating characteristic curve (AUC) were pooled using meta-analysis methods. Heterogeneity and publication bias were evaluated. Subgroups based on gender, country and study design were conducted as well.

RESULTS

Thirty-eight original articles including PURE-China were included into meta-analyses, involving 309,585 subjects. WHtR had the strongest association with hypertension risk (OR, 1.68; 95% confidence interval, [CI]:1.29-2.19) and prediction ability (AUC, 70.9%; 95% CI: 67.8%-74.2%), which were also confirmed in subgroup analyses based on gender and country. However, BMI was found to have the highest prediction ability in adjusted models of PURE-China and followed WC, both of which were superior to WHtR (73.7% and 73.4% vs 73.2%).

CONCLUSIONS

Our overall meta-analysis further confirmed WHtR as a good indicator at discriminating those individuals at increased risk of hypertension, and in some cases, it is better than BMI, WC, and WHR.

The value of hip circumference/heightx ratio for identifying childhood hypertension

To investigate the value of hip circumference related indexes for identifying childhood hypertension. In 2011, 1,352 Han children aged 7–12 years were recruited in our study. Hypertension was defined as systolic blood pressure or diastolic blood pressure ≥95th percentile for all three screenings. We set the power value of the hip circumference/height^x ratio (x = 0, 0.8, 1 and 1.5) and studied the association with blood pressure. Hip circumference, hip circumference/height^0.8, hip circumference/height and hip circumference/height^1.5 all showed a positive correlation with systolic blood pressure and diastolic blood pressure(P < 0.05). Area under the curve (AUC) was used to evaluate the abilities of hip circumference related indexes. Hip circumference/height^0.8, hip circumference/height and hip circumference/height1.5 were not superior to hip circumference. The present study demonstrates that hip circumference measurement is a helpful tool to detect the presence of hypertension in Han children 7–12 years old.

Associations between general and central obesity and hypertension among children: The Childhood Obesity Study in China Mega-Cities

In this study, we examined the associations of general and central obesity and hypertension among Chinese children. Data was collected from 1626 children aged 7-16 years and their parents in four mega-cities across China. Mixed effect models examined associations of general and central obesity with hypertension, and between body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR), systolic blood pressure (SBP) and diastolic blood pressure (DBP). The prevalence of general obesity, central obesity, and hypertension among the children was 11.1%, 19.7%, and 9.0%, respectively. More boys had general and central obesity than girls (15.2% vs. 6.9%; 27.4% vs. 11.7%, respectively; both P < 0.0001). Sex difference in hypertension rate was not statistically significant (9.3% in boys vs. 8.8% in girls, P = 0.7341). Both SBP and DBP were positively associated with BMI, WC, and WHtR, regardless of sex and region. General obesity (OR = 5.94, 95% confidence interval [CI]: 3.69-9.55) and central obesity (OR = 3.45, 95% CI: 2.27-5.23) were strongly associated with hypertension. The prevalence of general obesity, central obesity, and hypertension was high among Chinese children in the four mega-cities across China. Children's BMI, WC, and WHtR were positively associated with their SBP and DBP. Obese children were 3-6 times more likely to have hypertension.

Blood pressure effects of adiposity in non-overweight children aged 6-17 years

BACKGROUND

Obesity is a well-established risk factor of elevated blood pressure; however, the relationships between normal weight status and the risk of hypertension and pre-hypertension are not clear.

AIM

The aim of this study is to describe the blood pressure effects of adiposity in non-overweight children.

METHODS AND RESULTS

In total, 588 097 non-overweight children aged 6-17 years were included from the National Surveys on Students' Constitution and Health. A non-linear relationship was found between age- and gender-standardised body mass index (BMI) z-score and pre-hypertension and hypertension, respectively. The odds ratios and 95% confidence intervals [ORs (95% CIs)] of pre-hypertension were 0.61 (0.59-0.63), 0.67 (0.65-0.68), 0.83 (0.83-0.84), 1.00 (reference), 1.13 (1.12-1.14), 1.18 (1.16-1.20) and 1.20 (1.18-1.22) for BMI z-scores of -1.2, -1.0, -0.5, 0 (reference), 0.5, 0.7 and 0.8, respectively. The ORs (95% CIs) of hypertension were 0.56 (0.54-0.58), 0.62 (0.61-0.64), 0.81 (0.80-0.82), 1.00 (reference), 1.17 (1.16-1.18), 1.23 (1.22-1.5) and 1.27 (1.24-1.29) for BMI z-scores of -1.2, -1.0, -0.5, 0 (reference), 0.5, 0.7 and 0.8, respectively. The above-mentioned associations were consistent in sub-group analysis by age, gender and height.

CONCLUSIONS

Non-linear relationships of BMI z-scores with pre-hypertension and hypertension were found in non-overweight children. Interventions to control blood pressure are also important in non-overweight children.

Prevalence of high blood pressure subtypes and its associations with BMI in Chinese children: a national cross-sectional survey

Background

Data on prevalence and characteristics of different high blood pressure subtypes are lacking among Chinese children. Regarding the mechanistic differences between isolated systolic high blood pressure and isolated diastolic high blood pressure and their different impact on end organ diseases, it is necessary to examine the prevalence of different high blood pressure subtypes in Chinese children and explore their associations with adiposity.

Methods

Data were derived from the baseline data of a multi-centered cluster randomized controlled trial involving participants from China. High blood pressure was defined according to age-, gender- and height-specific 95th percentile developed by the National High Blood Pressure Education Program Working Group. Body mass index was used to classify underweight, normal weight, overweight and obesity.

Results

The prevalence of HBP was 10.2% and 8.9% for boys and girls, respectively. Isolated systolic high blood pressure is the dominant high blood pressure subtype among Chinese boys aged 6–17 years and girls aged 12–17 years, while isolated diastolic high blood pressure was the most common high blood pressure subtype in girls aged 6–11 years. In boys, the status of overweight doubled the risk of isolated systolic high blood pressure (95% CI, 1.73, 2.31; P < 0.001) compared with the normal weight group, and the risk for obese children was 4.32 (95% CI, 3.81, 4.90; P < 0.001). The corresponding odds ratios in girls were 2.04 (95% CI, 1.68, 2.48, P < 0.001) for overweight, and 4.0 (95% CI, 3.36, 4.76, P < 0.001) for obesity. Similar patterns were also observed in the association between combined systolic and diastolic high blood pressure and adiposity.

Conclusion

The distribution of high blood pressure subtypes in boys differed from those in girls, and boys with adiposity showed a higher risk of high blood pressure than their female counterpart. Difference in strength of association between isolated diastolic high blood pressure and isolated systolic high blood pressure with body mass index was also found. These results may aid current strategies for preventing and controlling pediatric hypertension.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-017-4522-2) contains supplementary material, which is available to authorized users.

Obesity

Excessive fat deposition in obesity has a multifactorial aetiology, but is widely considered the result of disequilibrium between energy intake and expenditure. Despite specific public health policies and individual treatment efforts to combat the obesity epidemic, >2 billion people worldwide are overweight or obese. The central nervous system circuitry, fuel turnover and metabolism as well as adipose tissue homeostasis are important to comprehend excessive weight gain and associated comorbidities. Obesity has a profound impact on quality of life, even in seemingly healthy individuals. Diet, physical activity or exercise and lifestyle changes are the cornerstones of obesity treatment, but medical treatment and bariatric surgery are becoming important. Family history, food environment, cultural preferences, adverse reactions to food, perinatal nutrition, previous or current diseases and physical activity patterns are relevant aspects for the health care professional to consider when treating the individual with obesity. Clinicians and other health care professionals are often ill-equipped to address the important environmental and socioeconomic drivers of the current obesity epidemic. Finally, understanding the epigenetic and genetic factors as well as metabolic pathways that take advantage of 'omics' technologies could play a very relevant part in combating obesity within a precision approach.

Blood pressure profiles of children and adolescents categorized by waist-to-height ratio cutoffs: study in a large sample in Shandong, China

BACKGROUND

Waist-to-height ratio (WHtR) is proposed as a simple and effective screening tool for abdominal obesity and cardiovascular disease risk factors. The present study examined the profiles of blood pressure (BP) among children and adolescents categorized by WHtR cutoffs.

PATIENTS AND METHODS

A total of 28 074 (14 015 boys and 14 059 girls) students aged 7-17 years participated in the study. Height, waist circumference and BP of all patients were measured, and WHtR was calculated. Relatively high blood pressure (RHBP) status was defined as systolic BP and/or diastolic BP of at least the 95th percentile for age and sex. All patients were divided into three groups (low, moderate and high) according to their WHtR. BP level and the prevalence of RHBP among the three groups were compared.

RESULTS

In both boys and girls, significant differences in BP level and the prevalence of RHBP were observed among the three groups (P<0.01). Children and adolescents aged 7-17 years in the 'high WHtR group' (≥0.5) had higher systolic BP and diastolic BP compared with those in the 'low WHtR group' (<0.4) by 6.07-11.49 and 3.28-6.34 mmHg for boys and 5.62-9.76 and 3.14-5.95 mmHg for girls; the 'high WHtR group' had the highest (34.02% for boys and 30.87% for girls) and the 'low WHtR group' had the lowest prevalence of RHBP (15.23% for boys and 12.53% for girls).

CONCLUSION

High WHtR is associated with elevated BP. These findings emphasize the importance of the prevention of abdominal obesity to prevent future problems such as hypertension in children and adolescents.

Evaluation of Hip/HeightP Ratio as an Index for Adiposity and Metabolic Complications in Obese Children: Comparison with Waist-related Indices

Aim: To investigate whether body adiposity index (BAI; hip/height^1.5–18), pediatric BAI (BAIp; hip/height^0.8–38), and other hip/height^P ratios are useful in obese children.

Method: Ninety obese Japanese children, 55 boys and 35 girls, who visited our University Clinic, were enrolled. The age was 9.92 ± 2.6 (mean ± SD) years, and the percentage overweight (POW) was 51.6 ± 18.8%. We set the power value of the hip/height^P 0, 0.5, 0.8, 1, 1.5, and 2 and studied the association with overweight indices, biochemical data, and fat area measured by computed tomography. Waist, waist/height ratio, and waist/hip ratio were also evaluated.

Results: Hip/height and hip/height^0.8 (BAIp) were more closely correlated with POW, body mass index percentile, and percentage body fat than hip/height^1.5 (BAI). The correlation coefficient of hip/height with POW (r = 0.855) was the highest among the studied hip/height^P indices. The approximate line to predict POW was 411 × hip/height−207. The waist/height was also highly correlated with POW (r = 0.879). Hip and hip/height^0.5 were more closely correlated with visceral fat area than hip/height, BAIp, and hip/height^1.5. Hip and hip/height^0.5 were significantly correlated with insulin. Only hip was also significantly associated with dyslipidemia. All hip/height^P indices were not significantly correlated with alanine aminotransferase (ALT). Waist was significantly correlated with serum lipids, ALT, and insulin.

Conclusion: Hip/height and BAIp are better markers for overweight (adiposity) in obese children than BAI. However, hip/height, BAIp, and BAI are not useful to predict metabolic complications. Waist appears to be the best index for obese children overall at this time.

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.

Role of waist measures in addition to body mass index to assess the hypertension risk in children

AIM

This study aimed to evaluate whether waist measures, including waist circumference (WC) and waist-to-height ratio (WHtR), can improve the ability of body mass index (BMI) to assess the hypertension risk when used as continuous variables.

METHODS

In this cross-sectional study, 82 432 Chinese children aged 9-17 years were included. Elevated BP was defined using age-sex-and-height-specific references. Logistic regression model and area under the receiver operating characteristic curve (AUC) were performed after BMI and waist measures were converted into age-and-sex-based z-scores.

RESULTS

WHtR, but not WC, was associated with elevated BP after adjusting for BMI, with the odds ratios ranging between 1.14 (95% confidence interval: 1.04, 1.25) and 1.30 (1.21, 1.39) for one unit increase in WHtR z-score. Combined use of BMI and WHtR z-scores showed a significantly larger AUC than BMI alone (p < 0.05), while joint use of BMI and WC was not better than BMI alone.

CONCLUSION

WHtR, rather than WC, provided further information on hypertension risk beyond that provided by BMI alone when used as a continuous variable. This study suggests WHtR, in addition to BMI, should be included for the assessment of childhood adiposity in routine paediatric practice.