The relationship between resting blood pressure, body mass index and lean body mass index in British children

Association between lean body mass and hypertension: A cross-sectional study of 50 159 NHANES participants

Increasing attention has been paid to the association between lean body mass (LBM) and hypertension in recent years, but the previous findings have often been contradictory. Therefore, the authors investigated the association between LBM and hypertension through a cross-sectional study in the United States. To investigate the relationship between LBM and hypertension, the authors conducted weighted multivariable logistic regression models. The authors used the restricted cubic spline regression model to determine if there was a nonlinear correlation. In order to locate the inflection point, the authors built a two-part linear regression model using a recursive method. In the full adjustment model, LBM was positively associated with hypertension, with ORs (95% CI) of 1.19 (1.02, 1.38). In the further linear trend test, the ORs (95% CI) for Q2, Q3, and Q4 were 0.76 (0.60, 0.95), 0.62 (0.47, 0.80), and 0.66 (0.48, 0.91), respectively, compared to Q1, which suggested that the association between LBM and hypertension might be non-linear. The authors performed the restricted cubic spline curve to confirm this non-linear relationship and found the inflection point of 43.21 kg with an opposite relationship in which LBM and hypertension exhibited a negative correction of 0.66 (0.50, 0.86) before the inflection point and a positive correlation of 1.20 (1.03, 1.39) after the inflection point. Our study highlighted a non-linear association between LBM and hypertension in the general US population.

The Correlation of Built Environment on Hypertension, and Weight Status amongst Adolescence in Saudi Arabia

The prevalence of hypertension is becoming more common in children and adolescents than ever before. Thus, the aim of this study was to evaluate the associations between the built environment on physical activity, sedentary behaviour, waist circumference, and health amongst adolescents in Saudi Arabia. A systolic and diastolic blood pressure, resting heart rate and waist circumference of 380 boys and girls aged between 15-19 years old (male = 199 and females = 181) were measured. The International physical activity Questionnaire Short Form was used to assess the physical activity levels and time spent sitting. The statistical analysis conducted were means and standard deviation, 2-way and 3-way of variance (ANOVA), Bonferroni post hoc tests, Chi-squared distribution and Pearson's correlations. Among males, 16.75% were classified as hypertensive, 12.69% as pre-hypertensive, and 70.56% as normal whereas, females, 23.20% were classified as hypertensive, 12.15% as pre-hypertensive and 64.64% as normal. There were significant differences (F_1,379 = 16.50, p < 0.001) between males and females waist circumference. Pearson's correlation also revealed significant positive relationships in sedentary time (r = 0.123, p < 0.016), WC (r = 0.104, p < 0.043), and systolic blood pressure (r = 0.110, p < 0.032). The results revealed that systolic and diastolic blood pressure are significantly related to multiple measures of weight status, and sedentary behaviour. The results also highlight that active youth had lower resting heart rate compared to inactive peers. The present findings provide a foundation of knowledge for future research and highlight the major need for research and policy interventions, to address the concerning health habits of Al-Ahsa youth and broader Kingdom of Saudi Arabia.

Effect of changes in body mass index and waist-to-height ratio on blood pressure in 11- to 13-year-old children: a prospective population study

BACKGROUND

Existing evidence about associations between change in body mass index (BMI) and waist-to-height ratio (WHtR) change and high blood pressure are relatively limited.

AIMS

We aimed to investigate the associations of general overweight (based on BMI) and abdominal obesity (based on WHtR) change with high blood pressure in Chinese children.

SUBJECTS AND METHODS

A school-based cohort study in Ningbo region (China) was conducted among children with baseline evaluations in October 2016 with follow-up two years later. A total of 1432 children aged 11-13 years participated in this study.

RESULTS

Our results showed that a change from normal BMI or WHtR to overweight or abdominal obesity in children was associated with high blood pressure (adjusted odds ratio (AOR), 2.62; p<0.05 or AOR, 2.79; p<0.05, respectively). In addition, an increased risk of high blood pressure was observed in children who maintained overweight or abdominal obesity (AOR, 1.67; p<0.05 or AOR, 1.69; p<0.05, respectively), but not in children who experienced remission to non-excess weight. Interestingly, children who increased BMI or WHtR had greater impact on SBP than on DBP.

CONCLUSION

The 2-year longitudinal study indicated that general overweight or abdominal obesity can predict the risk factor of high blood pressure in children. However, children who remitted to non-excess weight did not exhibit an increased risk of high blood pressure.

Association between body composition and blood pressure in normal-weight Chinese children and adolescents

Background

The aim of this study was to assess the associations of body fat distribution and lean body mass (LBM) with blood pressure (BP) in normal-weight Chinese children and adolescents.

Methods

A total of 898 normal-weight Chinese children and adolescents, aged 10–18 years, were included this cross-sectional study via a cluster sampling method. The bioelectrical impedance analysis (BIA) was used to measure body composition. The participants were measured for blood pressure (BP) using a calibrated electronic sphygmomanometer according to the standard method by the "American Hypertension Education Project Working Group".

Results

Body composition was related to abnormal BP in normal-weight children and adolescents. After the model adjusted for age, smoking, and drinking, regression analysis showed that fat mass percentage (FMP) was negatively associated with abnormal BP, while LBM was positively associated with abnormal BP in boys(P < 0.05). Whereas FMP and visceral fat level (VFL) were positively associated with abnormal BP in girls (P < 0.05).

Conclusions

There are sex differences in the relationships between total body fat, visceral fat and lean body mass with abnormal BP in normal-weight youths. Therefore, it is of great significance to pay attention to the relative influence of the body composition of the boys and girls in the prevention and treatment of hypertension in youths.

Is Office Blood Pressure Measurement Reliable in Obese Adolescents?

BACKGROUND

Although it is not reflected in the OBP measurement in obese children, ambulatory BP changes are known to occur. MH, non-dipper pattern and nocturnal hypertension have been reported to increase in obese children. On the other hand, the factors that indicate a high risk of hypertension are still unclear. The aim of our study is to especially detect masked hypertension by 24-hour BP measurement in obese adolescents and to evaluate the relationship of masked hypertension with metabolic syndrome parameters, anthropometric measurements and hepatosteatosis in these patients.

METHODS

A total of 63 adolescents diagnosed with obesity were evaluated between January 2019 and December 2019. Office blood pressure was measured for all children, and all of them underwent ABPM. Patients with and without hypertension in ABPM were compared in terms of clinical and laboratory findings.

RESULTS

The mean age was 14.0 ± 1.7 years, females composed 49.2% of the study population. Office blood pressure measurement revealed hypertension in 4 (6.3%) patients and prehypertension in 15 (23.8%) patients. Thirteen patients (20.9%) were diagnosed with masked hypertension, white coat hypertension was diagnosed in 3 (4.7%) patients. Abnormal ABPM patterns were found to be significantly more frequent in patients with severely obesity (with obesity: 26.4% vs severe obesity: 55.6%, p = 0.03) and patients with a higher waist circumference and waist circumference/height ratio.

CONCLUSION

The prevalence of masked hypertension in obese adolescents has been found to be quite high. Therefore, we recommend ABPM in adolescents with high waist circumference/height ratio and severe obesity, even if their office blood pressure measurements are normal.

Percentage of free fat mass is associated with elevated blood pressure in healthy Chinese children

Previous studies have reported that a high free fat mass (FFM) was associated with elevated blood pressure in children. However, the observed relationship could be confounded by body weight. Thus, we performed cross-sectional analyses to understand the differences between the percentage of free fat mass (FFM%) and FFM in relation to blood pressure in healthy Chinese children. A total number of 2671 (1264 girls; aged 6-14 years) healthy Chinese children was recruited in 2014 (baseline). We further prospectively examined whether these indices predicted hypertension risk during the 2 years of follow-up (2014-2016) among 2094 participants who were free of hypertension at the baseline. Blood pressure was repeatedly measured in 2014, 2015 and 2016. Hypertension was defined as either high systolic blood pressure and/or high diastolic blood pressure (≥age- and sex-specific 95^th percentile for Chinese children). The baseline FFM was assessed by bio-impedance analysis, and FFM% was calculated as FFM divided by the body weight. A high FFM was associated with a high baseline blood pressure and high hypertension risk after adjustment for potential confounders (all p < 0.001). By contrast, a high FFM% was associated with a low baseline blood pressure and low hypertension risk in the fully adjusted model (all p < 0.001). Each one-percent increment of FFM% was associated with a 9% lower risk of developing hypertension (adjusted hazard ratio = 0.91; 95% confidence interval: 0.89, 0.94). A high FFM% was associated with a low blood pressure and low hypertension risk in healthy Chinese children.

The associations of body composition and anthropometric measures with carotid intima-media thickness in obese and non-obese schoolchildren: A possible predictor for cardiovascular diseases

Background

Increased carotid intima-media thickness is one of the predictors of future cardiovascular diseases. However, it is still unknown which body composition parameter or anthropometric measure is the best predictor for carotid intima-media thickness change among children and young adolescents.

Objective

To investigate the associations of body composition and anthropometric measures with carotid intima-media thickness among a group of obese and normal bodyweight schoolchildren.

Methods

A total of 125 schoolchildren (10–15 years) were recruited from four public schools in Amman, Jordan. Of them, 60 (29 boys and 31 girls) were normal bodyweight students and 65 (35 boys and 30 girls) were obese students. Anthropometric measures, fat mass and fat-free mass were determined. Carotid intima-media thickness of the common artery was measured using high-resolution B-mode ultrasound.

Results

Compared to normal bodyweight students, obese participants exhibited greater carotid intima-media thickness (mm) (0.45 ± 0.10 vs. 0.38 ± 0.08, p = 0.002) and fat-free mass (kg) (48.01 ± 11.39 vs. 32.65 ±7.65, p < 0.001). Pearson’s correlation coefficient and linear regression analysis revealed significant associations ( p≤0.05) between mean carotid intima-media thickness and body mass index, waist circumference, hip circumference, waist-to-hip ratio, fat mass and fat-free mass. Stepwise linear regression analysis revealed that waist circumference was the only measure that was statistically significant ( p ≤ 0.05) with mean carotid intima-media thickness (r2 = 0.129, p = 0.002).

Conclusions

Obesity is related to greater carotid intima-media thickness and other cardiovascular risk factors among schoolchildren. Waist circumference is more sensitive in predicting increased carotid intima-media thickness than other body composition or anthropometric measures. Waist circumference measurement in the analysis of future studies assessing the cardiovascular risk among obese children is warranted.

Development of hypertension in overweight adolescents: a review

The upward trend in adolescent hypertension is widely attributed to the adolescent obesity epidemic. Secular trends in adolescent prehypertension and hypertension have risen in congruence with increasing trends in the prevalence of overweight and obesity. The correlation between body mass index and blood pressure in adolescence is moderate to strong in most studies and strongest in those classified as overweight or obese. The mechanisms relating to the development of hypertension in overweight adolescents are unclear; however, a number of nonmodifiable and modifiable factors have been implicated. Importantly, certain clinical and biochemical markers in overweight adolescents are indicative of high risk for hypertension, including family history of hypertension and hyperinsulinemia. These characteristics may prove useful in stratifying overweight adolescents as high or low risk of comorbid hypertension. The treatment of overweight and obesity related hypertension in this population focuses on two key modalities: lifestyle change and pharmacotherapy. These approaches focus almost exclusively on weight reduction; however, a number of emerging strategies target hypertension more specifically. Among adolescents with overt hypertension there are also several factors that indicate higher risk of concurrent subclinical disease, persistent adult hypertension, and adult cardiovascular disease. This group may benefit substantially from more aggressive pharmacological treatments. Limitations in the literature relate to the paucity of studies reporting specific effects for the adolescent age group of overweight and obese individuals. Nonetheless, intervention for adiposity-related hypertension in adolescence may partially mitigate some of the cardiovascular risk in adulthood.

Lean body mass may explain apparent racial differences in carotid intima-media thickness in obese children

BACKGROUND

Racial differences in carotid intima-media thickness (cIMT) have been suggested to be associated with the disproportionally high prevalence of cardiovascular disease in black adults. The objective of this study was to evaluate the effects of cardiovascular risk factors on the racial differences seen in cIMT in obese children.

METHODS

Obese subjects aged 4 to 21 years were recruited prospectively. Height, weight, blood pressure, fasting insulin, glucose, lipid panel, high-sensitivity C-reactive protein, and body composition by dual-energy x-ray absorptiometry were obtained. B-mode carotid imaging was analyzed by a single blinded physician.

RESULTS

A total of 120 subjects (46 white, 74 black) were enrolled. Black subjects exhibited greater cIMT (0.45 ± 0.03 vs 0.43 ± 0.02 cm, P < .01) and higher lean body mass index (19.3 ± 3.4 vs 17.3 ± 3.2 kg/m², P = .02) than white subjects. Simple linear regression revealed modest associations between mean cIMT and race (R = 0.52, P < .01), systolic blood pressure (R = 0.47, P < .01), and lean body mass (R = 0.51, P < .01). On multivariate regression analysis, lean body mass remained the only measure to maintain a statistically significant relationship with mean cIMT (P < .01).

CONCLUSIONS

Black subjects demonstrated greater cIMT than white subjects. The relationship between race and cIMT disappeared when lean body mass was accounted for. Future studies assessing the association of cardiovascular disease risk factors to cIMT in obese children should include lean body mass in the analysis.

Inverted BMI rather than BMI is a better predictor of DEXA determined body fatness in children

This study compared body mass index (BMI) and inverted BMI (iBMI) as predictors of body fatness in 177 Portuguese children (149 girls and 96 boys) aged 7-16 years. Participants undertook measures of height and body mass from which BMI (kg/m(2)) and iBMI (cm(2)/kg) were determined. Maturation was determined via self-report and fat mass index (FMI, kg/m(2)) via dual-energy X-ray absorptiometry. Significant relationships were evident between BMI and iBMI and FMI (both P=0.0001). BMI was not normally distributed (P=0.0001) but iBMI was (P>0.05). Analysis of covariance identified that BMI and iBMI, controlling for maturation, were both significant predictors of FMI (both P=0.0001) but that iBMI predicted a slightly greater amount of the variance (adjusted R(2)=0.970) compared with BMI (adjusted R(2)=0.968). This study suggests that iBMI is a similar proxy for body fatness compared with BMI in children.

Establishing the optimal body mass index - body esteem relationship in young adolescents

Background

This study sought to compare the utility of either inverted body mass index or body mass index to optimise the relationship with body esteem in young adolescents Design: The study was cross sectional in design and assessed body esteem and weight status in756 young adolescents (394 boys, 362 girls, mean age ± S.D. 11.4 ± 1.6 years).

Methods

Body esteem was determined using the body esteem scale for children. Height and body mass were measured directly. Body mass index was determined as kg/m² and iBMI as cm²/kg.

Results

Results indicated that the association between iBMI and body esteem was curvilinear in nature and iBMI was the better predictor of body esteem (P = .001) predicting 21.3% of the variance in body esteem scores compared to 20.5% using BMI (P = .001). When split by gender, the curvilinear relationship was still evident but significantly different between boys and girls although iBMI remained a better predictor of body esteem compared to BMI in both boys and girls. The peak differed between gender groups with the association between iBMI and body esteem peaking at 642 cm²/kg for boys and 800.64 cm²/kg for girls.

Conclusion

This study suggests that iBMI is a better predictor of body esteem in young adolescents, and that the association between body esteem and iBMI is curvilinear in nature. However, the peak of body esteem scores occured at a lower degree of leanness for boys compared to girls and indicated that the point at which body esteem scores are highest for girls is at a point of extreme leanness whereas the peak for boys was within the values considered as ‘normal’ on the leanness to obesity continuum. iBMI may therefore be a useful measure of leanness for future studies examining the association between overweight/obesity and body esteem in young adolescents.

Associations between body mass index, waist circumference and body shape index with resting blood pressure in Portuguese adolescents

BACKGROUND

Elevated blood pressure (BP) in childhood and adolescence is associated with overweight and obesity. Recently a body shape index (ABSI) has been suggested as superior to body mass index (BMI, kg/m(2)) and waist circumference (WC) as a measure of disease risk.

OBJECTIVE

To examine the association between ABSI, BMI, WC and BP in Portuguese adolescents and to consider the role of ABSI, BMI and WC when examining this issue in adolescents.

METHODS AND PROCEDURES

Height, body mass, WC and resting blood pressure were assessed in 445 Portuguese adolescents (252 girls and 193 boys) aged 10-17 years.

RESULTS

ABSI, BMI and WC were all significantly related to both SBP and DBP (all p = 0.001 or better). ABSI, BMI and WC were all significant predictors of SBP and DBP for the whole sample and when analysed in separate gender groups (p = 0.001 or better in all cases). However, in all cases ABSI was a better predictor of BP than BMI or WC.

CONCLUSIONS

Although BMI and WC significantly predict resting BP in adolescents, the use of ABSI explained a greater amount of the variance in BP in this population. When examining the effect of weight status on BP, researchers should consider use of ABSI alongside BMI.

Comparisons between inverted body mass index and body mass index as proxies for body fatness and risk factors for metabolic risk and cardiorespiratory fitness in Portuguese adolescents

OBJECTIVES

To compare inverted body mass index (iBMI, cm(2) /kg) and body mass index (BMI, kg/m(2) ) as predictors of body fatness, metabolic risk, and cardiovascular fitness in adolescents.

METHODS

A cross-sectional school-based study was conducted on 445 Portuguese adolescents (252 girls and 193 boys) aged 10-17 years. Height and body mass were assessed to determine iBMI and BMI, percent body fatness was determined from skinfold measures (tricep, subscapular) using the Slaughter et al. (1988: Hum Biol 60: 709-723) regression equation and cardiorespiratory fitness (CRF) was assessed using the 20-m shuttle run test. Capillary blood sampling was used to determine: Total cholesterol, triglycerides, high, and low density lipoprotein. These were combined with measures of systolic blood pressure and waist circumference as z-scores. Metabolic risk (MRS) was constructed by summing the z-scores.

RESULTS

iBMI and BMI were both significantly related to percent body fatness, CRF and MRS (all P = 0.005 or better). BMI was not normally distributed (P = 0.0001), whereas iBMI was (P > 0.05). Regression analysis identified that iBMI and BMI, both alongside for age, were significant predictors of percent body fatness, CRF and MRS (all P = 0.005 or better). Compared with BMI, iBMI was a similar predictor of CRF, MRS and body fatness.

CONCLUSIONS

iBMI offers a biologically sound alternative to BMI to assess the effect of weight status on MRS and CRF in adolescents and allows appropriate use of parametrical statistical techniques without changing the conclusions drawn from such data.