Performance of obesity indices for screening elevated blood pressure in pediatric population: Systematic review and meta-analysis

Obesity and hypertension in children and adolescents

As childhood obesity rates increase worldwide, the prevalence of obesity-related hypertension is also on the rise. Obesity has been identified as a significant risk factor for hypertension in this age group. National Health Surveys and meta-analyses show increasing trends in obesity and pediatric hypertension in obese children. The diagnosis of hypertension in children involves percentiles relative to age, sex, and height, unlike in adults, where absolute values are considered. Elevated blood pressure (BP) in childhood is consistently associated with cardiovascular disease in adulthood, emphasizing the need for early detection and intervention. The pathogenesis of hypertension in obesity involves multiple factors, including increased sympathetic nervous system activity, activation of the renin-angiotensin-aldosterone system (RAAS), and renal compression due to fat accumulation. Obesity disrupts normal RAAS suppression and contributes to impaired pressure natriuresis and sodium retention, which are critical factors in the development of hypertension. Risk factors for hypertension in obesity include degree, duration, and distribution of obesity, patient age, hormonal changes during puberty, high-sodium diet, sedentary lifestyle, and socioeconomic status. Treatment involves lifestyle changes, with weight loss being crucial to lowering BP. Medications such as angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers may be considered first, and surgical approaches may be an option for severe obesity, requiring tailored antihypertensive medications that consider individual pathophysiology to avoid exacerbating insulin resistance and dyslipidemia.

Lean body mass positively associate with blood pressure in Chinese adults: the roles of ages and body fat distribution

BACKGROUND

The relationship between lean body mass (LBM) and blood pressure (BP) is controversial and limited. This study investigated the associations between LBM indexes and BP in adults of different ages and with varying body fat distribution.

METHODS

The data for the present analysis was obtained from a cross-sectional survey of 1,465 adults (50.7% males) aged 18-70 years conducted in Beijing, China. Regional LBM and fat distribution, including fat mass (FM) and android to gynoid fat ratio (AOI), were assessed using a dual-energy X-ray bone densitometer. Generalized Liner Model (GLM) was employed. Confounders, including age, sex, height, weight, smoking, and alcohol use, were evaluated through questionnaires and physical examinations.

RESULTS

Males had higher rates of hypertension (11.19% vs. 4.92%) and prehypertension (21.57% vs. 14.59%) than females. The mean systolic blood pressure (SBP) and diastolic blood pressure (DBP) were 122.04 mmHg and 76.68 mmHg. There were no significant associations between LBM and DBP (p > 0.05). However, arms LBM (β = 1.86, 95% CI: 0.77, 2.94) and trunk LBM (β = 0.37, 95% CI: 0.01, 0.73) were significantly associated with SBP. The association of LBM on DBP was stronger with increasing ages, and stronger in females than in males (p < 0.001). The association between adults' arms LBM and SBP was stronger in the high level FM group (β = 2.74 vs. β = 1.30) and high level AOI group (β = 1.80 vs. β = 2.08).

CONCLUSION

The influence of LBM on SBP increases with age, particularly after the age twenty years in females. For adults with high FM or high AOI, LBM in the arms, showed a stronger positive predictive association with SBP. This suggests that, in addition to controlling fat content, future efforts to improve cardiovascular health in adults should include the management of LBM (especially in the upper body).

Establishing international optimal cut-offs of waist-to-height ratio for predicting cardiometabolic risk in children and adolescents aged 6-18 years

BACKGROUND

Waist-to-height ratio (WHtR) has been proposed as a simple and effective screening tool for assessing central obesity and cardiometabolic risk in both adult and pediatric populations. However, evidence suggests that the use of a uniform WHtR cut-off of 0.50 may not be universally optimal for pediatric populations globally. We aimed to determine the optimal cut-offs of WHtR in children and adolescents with increased cardiometabolic risk across different countries worldwide.

METHODS

We used ten population-based cross-sectional data on 24,605 children and adolescents aged 6-18 years from Brazil, China, Greece, Iran, Italy, Korea, South Africa, Spain, the UK, and the USA for establishing optimal WHtR cut-offs. We performed an external independent test (9,619 children and adolescents aged 6-18 years who came from other six countries) to validate the optimal WHtR cut-offs based on the predicting performance for at least two or three cardiometabolic risk factors.

RESULTS

Based on receiver operator characteristic curve analyses of various WHtR cut-offs to discriminate those with ≥ 2 cardiometabolic risk factors, the relatively optimal percentile cut-offs of WHtR in the normal weight subsample population in each country did not always coincide with a single fixed percentile, but varied from the 75th to 95th percentiles across the ten countries. However, these relatively optimal percentile values tended to cluster irrespective of sex, metabolic syndrome (MetS) criteria used, and WC measurement position. In general, using ≥ 2 cardiometabolic risk factors as the predictive outcome, the relatively optimal WHtR cut-off was around 0.50 in European and the US youths but was lower, around 0.46, in Asian, African, and South American youths. Secondary analyses that directly tested WHtR values ranging from 0.42 to 0.56 at 0.01 increments largely confirmed the results of the main analyses. In addition, the proposed cut-offs of 0.50 and 0.46 for two specific pediatric populations, respectively, showed a good performance in predicting ≥ 2 or ≥ 3 cardiometabolic risk factors in external independent test populations from six countries (Brazil, China, Germany, Italy, Korea, and the USA).

CONCLUSIONS

The proposed international WHtR cut-offs are easy and useful to identify central obesity and cardiometabolic risk in children and adolescents globally, thus allowing international comparison across populations.

Incidence of Arterial Hypertension is Associated with Adiposity in Children and Adolescents

BACKGROUND

The increase of hypertension in children and adolescents has attracted the attention of the scientific community largely due to its association with the obesity epidemic.

OBJECTIVES

To describe the incidence of hypertension and its relationship with the cardiometabolic and genetic profile in children and adolescents from a city in southern Brazil in a three-year period.

METHODS

This longitudinal study followed 469 children and adolescents, aged 7-17 years old (43.1% boys), assessed at two-time points. We evaluated systolic and diastolic blood pressures (SBP and DBP), waist circumference (WC), body mass index (BMI), body fat percentage (%BF), lipid profile, glucose, cardiorespiratory fitness (CRF), and rs9939609 Polymorphism ( FTO ). Cumulative incidence of hypertension was calculated, and multinomial logistic regression was conducted. The statistical significance was established as p < 0.05.

RESULTS

After three years, the incidence of hypertension was 11.5%. Overweight or obese individuals were more likely to become borderline hypertensive (overweight OR: 3.22, 95% CI: 1.08-9.55; obesity OR: 4.05, 95% CI: 1.68-9.75), and obese individuals were more likely to become hypertensive (obesity OR: 4.84, 95% CI: 1.57-14.95). High-risk WC and %BF values were associated with hypertension development (OR: 3.41, 95% CI: 1.26-9.19; OR: 2.49, 95% CI: 1.08-5.75, respectively).

CONCLUSIONS

We found a higher incidence of hypertension in children and adolescents as compared with previous studies. Individuals with higher values of BMI, WC and %BF at baseline were more likely to develop hypertension, suggesting the importance of adiposity in the development of hypertension even in such a young population.

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.

Subcutaneous Adipose Tissue Measured by B-Mode Ultrasound to Assess and Monitor Obesity and Cardio-Metabolic Risk in Children and Adolescents

Simple Summary

The prevention and treatment of childhood and adolescent overweight and obesity raises the need for accurate body fat assessment. Precise methods are at high technical expense, require exposure to ionizing radiation and are limited to institutional investigations, while common body indicators fail to identify excess body fat. Subcutaneous adipose tissue measured by ultrasound is an alternative approach, which was evaluated in relation to commonly applied body indicators to assess cardio–metabolic risk and its applicability in the field. Subcutaneous adipose tissue measured by ultrasound indicated a clear advantage over commonly applied body indicators and implies that severe body fat assessment errors are to be expected when BMI is used as a measure for body fatness in children. Children or adolescents with identical BMIs may have large differences (>200%) in their amount of subcutaneous adipose tissue. Ultrasound provides an easily applicable, reliable and safe method for accurate assessment of obesity and monitoring treatment responses in children and adolescents at cardio–metabolic risk.

Abstract

Monitoring of children at heightened risk of cardio–metabolic diseases raises the need for accurate assessment of obesity. A standardized approach for measuring subcutaneous adipose tissue (SAT) by bright-mode ultrasound was evaluated in relation to body indices and anthropometry in a cross-sectional sample of 76 South African children (7–10 years) and 86 adolescents (13–17 years) to assess cardio–metabolic risk. SAT was higher in girls as compared to boys (children: 50.0 ± 21.7 mm > 34.42 ± 15.8 mm, adolescents: 140.9 ± 59.4 mm > 79.5 ± 75.6 mm, p < 0.001) and up to four times higher in adolescents than in children. In children, measures of relative body weight showed only a poor correlation to SAT (BMI: r = 0.607, p < 0.001), while in adolescents, BMI correlated high with SAT (r = 0.906, p < 0.001) based on high rates of overweight and obesity (41.8%). Children with identical BMIs may have large differences (>2–3-fold) in their amount of SAT. The moderate association to systolic (r = 0.534, r = 0.550, p < 0.001) and diastolic blood pressure (r = 0.402, r = 0.262, p < 0.001) further substantiates that SAT measured by ultrasound provides an accurate, safe and easy applicable approach for monitoring in children and adolescents at cardio–metabolic risk.

Are Body Composition Parameters Better than Conventional Anthropometric Measures in Predicting Pediatric Hypertension?

Body composition (BC) parameters are associated with cardiometabolic diseases in children; however, the importance of BC parameters for predicting pediatric hypertension is inconclusive. This cross-sectional study aimed to compare the difference in predictive values of BC parameters and conventional anthropometric measures for pediatric hypertension in school-aged children. A total of 340 children (177 girls and 163 boys) with a mean age of 8.8 ± 1.7 years and mean body mass index (BMI) z-score of 0.50 ± 1.24 were enrolled (102 hypertensive children and 238 normotensive children). Significantly higher values of anthropometric measures (BMI, BMI z-score, BMI percentile, waist-to-height ratio) and BC parameters (body-fat percentage, muscle weight, fat mass, fat-free mass) were observed among the hypertensive subgroup compared to their normotensive counterparts. A prediction model combining fat mass ≥ 3.65 kg and fat-free mass ≥ 34.65 kg (area under the receiver operating characteristic curve = 0.688; sensitivity = 66.7%; specificity = 89.9%) performed better than BMI alone (area under the receiver operating characteristic curve = 0.649; sensitivity = 55.9%; specificity = 73.9%) in predicting hypertension. In conclusion, BC parameters are better than anthropometric measures in predicting pediatric hypertension. BC measuring is a reasonable approach for risk stratification in pediatric hypertension.

Elevated blood pressure and its relationship with bodyweight and anthropometric measurements among 8-11-year-old Indonesian school children

Objective: Increased prevalence of elevated blood pressure in children and adolescents was associated with increased body weight and measures. Also, prevalence of elevated blood pressure varies between countries. This study is to investigate the prevalence of elevated blood pressure in Indonesian children and its relationship with bodyweight and anthropometric measures. Methods: This cross-sectional study involved 1010 elementary students aged 8 - 12 years (479 girls, 531 boys). The anthropometric measures and blood pressure were assessed. Elevated blood pressure (EBP) was determined if at the 90^th percentile or above for gender, age, and height. Independent t-test, Chi-square, Pearson correlation, and multivariate logistic regression were applied. Significance was determined at p<0.05. Results: Overall prevalence of EBP was 28.8% (35.9% in girls, 22.4% in boys). BMI, waist circumference (WC), waist to height ratio (WHtR), and abdominal skinfold had significant correlation with EBP. Elevated BP was higher in overweight and obesity than in normoweight (60.5% vs 39.5%, p=0.00). In girls, the OR of EBP for overweight and obesity were 2.33 (95% CI 1.40-3.87, p=0.03) and 3.44 (95% CI 1.98-5.99, p=0.00) whereas in boys were 4.26 (95% CI 2.20-8.28, p=0.00) and 8.82 (95% CI 5.10-15.38, p=0.00). Conclusions: Prevalence of EBP in Indonesian school children aged 8 - 11 years was higher and more prevalent in overweight/ obesity and in girls. Anthropometric measures were correlated with EBP.

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.

Dietary patterns and cardiometabolic risk factors among adolescents: systematic review and meta-analysis

This study systematised and synthesised the results of observational studies that were aimed at supporting the association between dietary patterns and cardiometabolic risk (CMR) factors among adolescents. Relevant scientific articles were searched in PUBMED, EMBASE, SCIENCE DIRECT, LILACS, WEB OF SCIENCE and SCOPUS. Observational studies that included the measurement of any CMR factor in healthy adolescents and dietary patterns were included. The search strategy retained nineteen articles for qualitative analysis. Among retained articles, the effects of dietary pattern on the means of BMI (n 18), waist circumference (WC) (n 9), systolic blood pressure (n 7), diastolic blood pressure (n 6), blood glucose (n 5) and lipid profile (n 5) were examined. Systematised evidence showed that an unhealthy dietary pattern appears to be associated with poor mean values of CMR factors among adolescents. However, evidence of a protective effect of healthier dietary patterns in this group remains unclear. Considering the number of studies with available information, a meta-analysis of anthropometric measures showed that dietary patterns characterised by the highest intake of unhealthy foods resulted in a higher mean BMI (0·57 kg/m²; 95 % CI 0·51, 0·63) and WC (0·57 cm; 95 % CI 0·47, 0·67) compared with low intake of unhealthy foods. Controversially, patterns characterised by a low intake of healthy foods were associated with a lower mean BMI (−0·41 kg/m²; 95 % CI −0·46,−0·36) and WC (−0·43 cm; 95 % CI −0·52,−0·33). An unhealthy dietary pattern may influence markers of CMR among adolescents, but considering the small number and limitations of the studies included, further studies are warranted to strengthen the evidence of this relation.

Influence of waist circumference on blood pressure status in non-obese adolescents

Objectives To check whether excess in abdominal adiposity and metabolic factors were associated with blood pressure abnormalities in non-obese adolescents. Methods We randomly selected 1100 adolescent students, aged 12-18 years, from schools and classrooms in the city of Constantine, Algeria. Among them 179 were overweight and 51 were obese (IOTF criteria). Waist circumference (WC) was considered high if >74 cm in boys and 75 cm in girls (mean of WC of all population studied). Hypertension (HBP) and prehypertension (preHBP) were defined by the NHBPEP's 2004 criteria. Results The prevalence of HBP/preHBP were 13.0%/12.4% with no difference between boys and girls. The percentages of HBP/preHBP patients were 15.6%/15.6% in overweight adolescents, 5.9%/31.4% in obese adolescents and 12.9%/10.6% in adolescents with normal body weight (p < 0.0001). In obese adolescents, the prevalence of HBP was higher among boys than girls (36% vs. 27%, p = 0.002). In normal and overweight adolescents, the prevalence of HBP and preHBP was similar in boys and girls (11.9% vs. 11.0% and 14.7% vs. 12.1%); the association of WC (high vs. not high) with HBP was found in boys (16.1% vs. 8.8%, p = 0.009) but not in girls (12.1% vs. 10.2%), and with preHBP in girls (15.5% vs. 8.0%, p = 0.029) but not in boys (16.2% vs. 13.6%). Waist circumference [OR: 1.04 (1.03-1.06); p < 0.0001] and HOMA index [OR: 1.65 (1.13-2.39); p = 0.009] were associated with an increased risk of HBP. Conclusion In non-obese adolescents, a high WC, defined by values over the mean WC observed in our population, is associated with a higher risk of HBP in boys.