Adiposity measures and blood pressure in Chinese children and adolescents

Influence of puberty on relationships between body composition and blood pressure: a cross-sectional study

BACKGROUND

Fat mass (FM) and fat-free mass (FFM) are positively associated with blood pressure (BP) in youth. Yet, how puberty, independent of age, affects these relationships remains unclear. Given puberty may be a crucial period for cardiometabolic health, we examined how pubertal development moderates the associations of FM/FFM with BP.

METHODS

Pubertal development, resting BP, and body composition were assessed in a convenience sample of youth (5.5-17 years). General linear models were conducted to assess if pubertal development moderated the relationships between FM/FFM and systolic/diastolic BP standardized for age, sex, and height (SBPz/DBPz).

RESULTS

Among participants (N = 1405; age: M = 13.3 ± 2.9 years; 65.4% female; 53.2% racial/ethnic minority), FM/FFM were positively associated with SBPz and DBPz (ps ≤ 0.02). Pubertal development moderated the associations between FFM and BPz (ps ≤ 0.01), but not FM (ps > 0.43). For early/mid and late pubertal participants, there were positive associations between FFM and BP (DBPz: βs = 0.10-0.18, ps ≤ 0.01; SBPz: βs = 0.33-0.43, ps < 0.001); however, these relationships were attenuated, especially for prepubertal DBPz (DBPz: β = 0.01, p = 0.91; SBPz: β = 0.24, p = 0.001).

CONCLUSIONS

Puberty moderated the relationships between FFM and SBPz/DBPz in analyses that separately modeled the contributions of age and sex. These data suggest that the FFM-DBPz association may potentially be impacted by increasing sex hormone concentrations during puberty.

IMPACT

Fat mass (FM) and blood pressure (BP) were positively associated throughout puberty. Fat-free mass (FFM) and BP were positively associated throughout puberty; however, puberty moderated the FFM-BP relationship, such that there was a positive relationship in early/mid and late puberty, but the relationship was attenuated for prepubertal children. These findings contribute further insight into physiological and cardiometabolic changes occurring during puberty. Changes in hormone concentrations may explain the impact puberty has on the FFM-BP relationship. Understanding predictors of BP are important as childhood BP is associated with future cardiometabolic outcomes.

Mixed effects logistic regression analysis of blood pressure among Ghanaians and associated risk factors

Blood pressure (BP) control is a global health issue with an increase in BP beyond the normal BP leading to different stages of hypertension in humans and hence the need to identify risk factors of BP for efficient and effective control. Multiple BP measurement have proven to provide BP readings close to the true BP status of the individual. In this study, we used multiple BP measurement data on 3809 Ghanaians to determine risk factors associated with BP. The data were obtained from World Health Organization study on Global AGEing and Adult Health. We defined high blood pressure (HBP) as [Formula: see text] 130/80 mmHg or normal as [Formula: see text] 130/80 mmHg. We provide summary statistics and also used the Chi-Square test to assess significance of association between HBP versus risk factors of HBP. The aim of this study is to identify risk factors of BP using the mixed effects logistic regression model. Data were analyzed using R version 4.2.2. The results showed that the risk of high blood pressure (HBP) decreases across the three measurement periods. There is reduced risk (OR = 0.274, 95% CI = 0.2008, 0.405) of HBP among male participants relative to female participants. The risk (OR = 2.771, 95% CI = 1.8658, 4.1145) of HBP increased by 2.771-folds among those who are 60 years and above relative to those below the age of 60 years. Those whose work involves/requires vigorous exercise has 1.631-fold increase in the risk (OR = 1.631, 95% CI = 1.1151, 2.3854) of HBP relative to those whose work does not involve vigorous exercise. There is approximately 5-folds increased in the risk (OR = 4.896, 95% CI = 1.9535, 12.2268) of among those who have ever been diagnosed with diabetes. The results also revealed high risk (OR = 1.649, 95%CI = 1.1108, 2.4486) of HBP among those who have formal education. The risk (OR = 1.009, 95% CI = 1.0044, 1.0137) of HBP increases with increasing weight and a reduced risk (OR = 0.996, 95% CI = 0.9921, 0.9993) of HBP with increasing height. We found that sad experience, either mild, moderate or severe, is associated with a reduced risk of HBP. Those who have vegetable servings at least 2 cups per day have increased risk of HBP and those who have fruits servings at least 2 cups per day is associated with a reduced risk of HBP, however this is not statistically significant. To achieve success in BP control, programs should be designed with the aim of reducing weight, educate those with formal eduction on issues relating to HBP. Those whose work requires vigorous exercise are recommended to have regular check-ups to ensure that pressure build-up in the lungs is cleared. SBP is lower for women at young age but continue to increase after menopause as their BP increase becomes salt-sensitive. Hence there is need to give more attention to menopausal women so as to improve BP. Both young and old individuals are recommended to practice regular exercise since this has shown to reduce risk of being overweight or becoming diabetic and reduces the risk of HBP at yong age and old age. Also, to improve blood pressure control, programs for management of blood pressure or hypertension should focus more short stature individuals since such people are more likely to experience HBP.

Prognostic Potential of the Body Composition Indices in Predicting Positive Changes in Resting Blood Pressure after High-Intensity Interval Training in Adolescents

This study aimed to investigate the prognostic potential of body composition indices in predicting the improvement in resting blood pressure after 10 weeks of high-intensity interval training (HIIT) implemented in physical education lessons. The participants were 141 adolescents aged 16 years. Independent variables were body mass index (BMI), fat mass index (FMI), muscle mass index (SMI), and mass to fat ratio (MFR); dependent variables were systolic and diastolic blood pressure (SBP, DBP) and its indices: pulse pressure (PP), mid-blood pressure (MBP), and mean arterial pressure (MAP). The receiver operating curve (ROC) method was employed. SMI and MFR are body composition indices with prognostic potential to predict positive changes in SBP in males (SMI: AUC = 0.82; p < 0.001, MFR = 0.70; p = 0.039) and MFR in females (AUC = 0.72; p = 0.035). The respective cut-off point values used to classify participants as a beneficiary of HIIT intervention concerning SBP were SMI = 7.84 and MFR = 2.43 in males, and for SMI = 10.12 and MFR = 1.94 in females. Body composition indices based on skeletal muscle (SMI, MFR) were more likely to predict positive changes in SBP after HIIT intervention in adolescents. PP, MBP, and MAP did not reflect the detecting power of SMI and MFR. However, these thresholds' utility is limited to adolescents of 16 years of age.

Epidemiology and determinants of obesity in China

Obesity has become a major public health issue in China. Overweight and obesity have increased rapidly in the past four decades, and the latest national prevalence estimates for 2015-19, based on Chinese criteria, were 6·8% for overweight and 3·6% for obesity in children younger than 6 years, 11·1% for overweight and 7·9% for obesity in children and adolescents aged 6-17 years, and 34·3% for overweight and 16·4% for obesity in adults (≥18 years). Prevalence differed by sex, age group, and geographical location, but was substantial in all subpopulations. Strong evidence from prospective cohort studies has linked overweight and obesity to increased risks of major non-communicable diseases and premature mortality in Chinese populations. The growing burden of overweight and obesity could be driven by economic developments, sociocultural norms, and policies that have shaped individual-level risk factors for obesity through urbanisation, urban planning and built environments, and food systems and environments. Substantial changes in dietary patterns have occurred in China, with increased consumption of animal-source foods, refined grains, and highly processed, high-sugar, and high-fat foods, while physical activity levels in all major domains have decreased with increasing sedentary behaviours. The effects of dietary factors and physical inactivity intersect with other individual-level risk factors such as genetic susceptibility, psychosocial factors, obesogens, and in-utero and early-life exposures. In view of the scarcity of research around the individual and collective roles of these upstream and downstream factors, multidisciplinary and transdisciplinary studies are urgently needed to identify systemic approaches that target both the population-level determinants and individual-level risk factors for obesity in China.

Prevalence of sustained hypertension and obesity among urban and rural adolescents: a school-based, cross-sectional study in North India

OBJECTIVE

Recent data on sustained hypertension and obesity among school-going children and adolescents in India are limited. This study evaluates the prevalence of sustained hypertension and obesity and their risk factors among urban and rural adolescents in northern India.

SETTING

A school-based, cross-sectional survey was conducted in the urban and rural areas of Ludhiana, Punjab, India using standardised measurement tools.

PARTICIPANTS

A total of 1959 participants aged 11-17 years (urban: 849; rural: 1110) were included in this school-based survey.

PRIMARY AND SECONDARY OUTCOME MEASURES

To measure sustained hypertension among school children, two distinct blood pressure (BP) measurements were recorded at an interval of 1 week. High BP was defined and classified into three groups as recommended by international guidelines: (1) normal BP: <90th percentile compared with age, sex and height percentile in each age group; (2) prehypertension: BP=90th-95th percentile; and (3) hypertension: BP >95th percentile. The Indian Academy of Pediatrics classification was used to define underweight, normal, overweight and obesity as per the body mass index (BMI) for specific age groups.

RESULTS

The prevalence of sustained hypertension among rural and urban areas was 5.7% and 8.4%, respectively. The prevalence of obesity in rural and urban school children was 2.7% and 11.0%, respectively. The adjusted multiple regression model found that urban area (relative risk ratio (RRR): 1.7, 95% CI 1.01 to 2.93), hypertension (RRR: 7.4, 95% CI 4.21 to 13.16) and high socioeconomic status (RRR: 38.6, 95% CI 16.54 to 90.22) were significantly associated with an increased risk of obesity. However, self-reported regular physical activity had a protective effect on the risk of obesity among adolescents (RRR: 0.4, 95% CI 0.25 to 0.62). Adolescents who were overweight (RRR: 2.66, 95% CI 1.49 to 4.40) or obese (RRR: 7.21, 95% CI 4.09 to 12.70) and reported added salt intake in their diet (RRR: 4.90, 95% CI 2.83 to 8.48) were at higher risk of hypertension.

CONCLUSION

High prevalence of sustained hypertension and obesity was found among urban school children and adolescents in a northern state in India. Hypertension among adolescents was positively associated with overweight and obesity (high BMI). Prevention and early detection of childhood obesity and high BP should be strengthened to prevent the risk of cardiovascular diseases in adults.

Multifactorial correlates of blood pressure in South Asian children in Canada: a cross-sectional study

OBJECTIVE

We sought to explore various correlates of blood pressure (BP) and hypertension, and to identify the most important aggregate combination of correlates for BP in South Asian children.

DESIGN

Cross-sectional study SETTING: Community-based recruitment in two Canadian cities PARTICIPANTS: South Asian children (n=762) provided a range of physiological, lifestyle and social variables. BP was assessed using an automated device. Body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR) and BP were transformed to z-scores using published standards.

OUTCOME MEASURES

Linear and logistic regression analyses were used to explore associations between the range of variables with BP z-scores and hypertension while stepwise regression was used to identify aggregate factors that provided explanatory capacity for systolic BP (SBP) and diastolic BP (DBP) z-scores.

RESULTS

A range of variables were associated with BP z-score and hypertension in unadjusted analysis. On adjustment for confounders, the association between age (β=-0.054, 95% CI=-0.078 to 0.029), female sex (β=-0.208, 95% CI=-0.350 to -0.067), height (β=0.022, 95% CI=0.011 to 0.033), weight (β=0.047, 95% CI=0.040 to 0.055), BMI z-score (β=0.292, 95% CI=0.249 to 0.336), WC z-score (β=0.273, 95% CI=0.219 to 0.326), WHtR z-score (β=0.289, 95% CI=0.236 to 0.342), heart rate (β=0.016, 95% CI=0.010 to 0.022), child's perception of body image (β=0.183, 95% CI=0.128 to 0.239) and grip strength (β=0.025, 95% CI=0.007 to 0.043) with SBP z-score remained. In stepwise regression, age, sex, BMI z-score, heart rate and weight accounted for 30% of the variance of SBP z-score, while age, BMI z-score, heart rate and daily fast food intake accounted for 23% of the DBP z-score variance.

CONCLUSION

Our findings suggest that variables, such as age, sex, height, adiposity and heart rate, provide stronger explanatory capacity to BP variance and hypertension risk than other variables in South Asian children.

Association of Age-Related Trends in Blood Pressure and Body Composition Indices in Healthy Adults

Purpose: Adiposity is one of the important determinants of blood pressure. The aim of this study is to evaluate the association between blood pressure and body composition indices throughout the whole lifespan of healthy adults.

Patients and Methods: This study was from an ongoing cross-sectional survey of the Chinese health wherein data included basic physiological parameters. Partial Pearson correlation analysis was used to assess the correlation between blood pressure and body composition indices. Multiple linear regression analysis was used to assess the association of body mass index, lean mass percent, and visceral fat rating against blood pressure in each age group.

Results: In the whole population stratified by gender, while body mass index had the highest r-value of correlation with systolic blood pressure in both males (r = 0.296, p < 0.001) and females(r = 0.237, p < 0.001), and fat mass percent had the highest r-value of correlation with diastolic blood pressure in males (r = 0.351, p < 0.001) and females(r = 0.277, p < 0.001), the strength of association with blood pressure were similar across most of the body composition indices. In multiple linear regression analysis, both body mass index and visceral fat rating were positively while lean mass percent was negatively associated with blood pressure in all age groups in both genders, whereas all the association was weaker in the elderly compared to the younger.

Conclusion: Maintain the total body fat in a favorable range and appropriately increase the body muscle mass is a strategy to reduce the occurrence of cardiovascular event by decreasing the risk of hypertension through the whole adult life.

Measurement of Central Aortic Blood Pressure in Youth: Role of Obesity and Sex

BACKGROUND

The relationship between pediatric severe obesity (SO) and central aortic blood pressure (BP) has yet to be established.

METHODS

We conducted a cross-sectional study of 348 youth (48.5% male, age 12.7 ± 0.1 years) with a wide range of body mass index (BMI) values: normal weight (NW; ≥5th and <85th BMI percentiles), overweight/obesity (OW/OB; 85th to <120% of the 95th BMI percentile), and SO (≥120% of the 95th BMI percentile). Measures of central aortic BP were obtained via applanation tonometry with SphygmoCor MM3 software.

RESULTS

After adjustment for covariates, no significant sex differences were observed for radial-aortic systolic blood pressure (SBP) (P = 0.39), carotid-aortic SBP (P = 0.99), radial-aortic diastolic blood pressure (DBP) (P = 0.44), and carotid-aortic DBP (P = 0.53). Compared to youth with NW, youth with SO exhibited higher radial-aortic SBP (SO vs. NW: 102 ± 1 mm Hg vs. 90 ± 1 mm Hg, P<0.001), carotid-aortic SBP (SO vs. NW: 121 ± 1 mm Hg vs. 109 ± 1 mm Hg, P<0.001), and carotid-aortic DBP (SO vs. NW: 60 ± 1 mm Hg vs. 56 ± 1 mm Hg, P = 0.04). Compared to youth with OW/OB, youth with SO had higher radial-aortic SBP (OW/OB: 97 ± 1 mm Hg, P = 0.002) and carotid-aortic SBP (OW/OB: 114 ± 1 mm Hg, P = 0.007). After adjusting for either total-body percent fat mass or visceral adipose tissue, BMI was still a significant predictor of both radial-aortic and carotid-aortic SBP and DBP (P<0.001, all).

CONCLUSIONS

In a cohort of youth with a wide range of adiposity levels, central aortic BP was elevated among individuals with SO and associated with BMI but not body fatness.

Correlates of elevated blood pressure in healthy children: a systematic review

The prevalence of hypertension in children is increasing globally. Addressing this will require a robust understanding of associated risk factors. To this end, we conducted a systematic review to identify correlates of elevated blood pressure (BP) in children. Literature searches were conducted using pre-defined search terms from three academic databases. The abstract and full text of identified studies were screened for eligibility by two independent reviewers. A total of 100 studies were included in this systematic review. An assessment tool was first used to assess study quality; a narrative synthesis was then performed. We found a broad range of physiological, social and behavioural factors associated with elevated BP in children. The most common correlate observed was adiposity, suggesting that childhood obesity may be implicated in the increased prevalence of hypertension observed in children. However, the broad range of other factors identified underscores the multi-factorial aetiology of hypertension. Data from a broad range of studies showed that the correlates of hypertension in children are multi-factorial. Therefore, approaches aimed at preventing hypertension must in turn be multi-factorial to ensure that the burden of hypertension in childhood is addressed.

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.

Pathways from parental educational attainment to adolescent blood pressure

OBJECTIVES

Lower parental education is associated with higher adolescent blood pressure (BP). We examined the contribution of modifiable risk factors from infancy to adolescence that could potentially explain the link between parental education and SBP and DBP in the offspring.

METHODS

In a prospective Chinese birth cohort, 'Children of 1997' of 5604 adolescents (68% follow-up), we analyzed the relation between parental educational attainment and sex-specific, age-specific and height-specific BP z-scores at ∼13 years. Using mediation analysis, we examined the contribution of household income at birth (both absolute income and relative income deprivation), exposures during infancy (breastfeeding and early life second-hand smoking), lifestyles during childhood (diet, physical activity and screen-time), weight or BMI status during fetal, infancy, childhood and puberty, pubertal stage as well as parental BMI.

RESULTS

We found that adolescent BMI, but not birth weight or infant growth or childhood BMI, mediated the inverse association of parental education with adolescent SBP (proportion mediated: 24%), followed by maternal BMI (proportion mediated: 18%). Factors explaining the link between parental education and DBP were less clear. Absolute income, breastfeeding, childhood diet and physical activity, pubertal stage and paternal BMI did not mediate the association between parental education and adolescent BP.

CONCLUSION

Low parental education is a risk factor for high SBP and, to a lesser extent, DBP in adolescents. Important mediators of this relation include adolescent and maternal body weight.

Associations Between Obesity Indicators and Blood Pressure in Chinese Adult Twins

Obesity is associated with blood pressure (BP), but the associations between different obesity indicators and BP have not reached agreement. Besides, both obesity and BP are influenced by genetic and environmental factors. Whether they share the same genetic or environmental etiology has not been fully understood. We therefore analyzed the relationship between different obesity indicators and BP components as well as the genetic and environmental contributions to these relationships in a Chinese adult twin sample. Twins aged 18–79 years (n = 941) were included in this study. Body mass index (BMI) was used as the index of general obesity, whereas waist circumference (WC), waist-to-height ratio (WHtR), and waist-to-hip ratio (WHR) were used as the indicators of central obesity. BP components included systolic blood pressure (SBP) and diastolic blood pressure (DBP). Linear regression models and bivariate structural equation models were used to examine the relation of various obesity indicators with BP components, and genetic or environmental influences on these associations, respectively. A strong association of BP components with BMI—and a somewhat weaker association with WC, WHtR, and WHR—was found in both sexes, independent of familial factors. Of these phenotypic correlations between obesity indicators and BP components, 60–76% were attributed to genetic factors, whereas 24–40% were attributed to unique environmental factors. General obesity was most strongly associated with high BP in Chinese adult twins. There were common genetic backgrounds for obesity and BP, and unique environmental factors also played a role.

[Arterial hypertension among adolescents in Rio de Janeiro: prevalence and association with physical activity and obesity]

The scope of this study was to identify the prevalence of systemic arterial hypertension among adolescent students (aged 17-19 years) in the third and final year of high school in state schools in the municipality of Rio de Janeiro, and to investigate associations between systemic arterial hypertension and obesity and physical activity levels. Data on arterial pressure, body mass index and physical activity were gathered. The analysis included 854 individuals. Descriptive statistical analysis was applied to the sample, along with a Poisson regression model to determine the impact of the variables on the prevalence of systemic arterial hypertension. The prevalence of systemic arterial hypertension was 19.4%. Male sex, overweight and obesity presented significant positive associations with systemic arterial hypertension (p < 0.05), while physical activity was not shown to be significantly associated with systemic arterial hypertension (p > 0.05). The nature of these relationships should be interpreted in the light of reflection and not of passive labeling based on hegemonic concepts.

Association between waist circumference and childhood-masked hypertension: A community-based study

AIM

The aim of this study is to determine the association between waist circumference (WC) and childhood-masked hypertension.

METHODS

A territory-wide, school-based cohort of 1385 Hong Kong students (672 boys and 713 girls) aged 8-17 years was analysed. The ambulatory blood pressure-monitoring assessment was performed using validated oscillometric recorders (A&D TM-2430 (A&D Inc., Tokyo, Japan)) following American Heart Association's recommendations. Subjects were considered normotensive if their casual blood pressure, 24-h daytime and night-time average systolic blood pressure and diastolic blood pressure (DBP) were <95th percentile. If one or more of the ambulatory blood pressure parameters was ≥95th percentile, subjects would be considered suffering from masked hypertension (MH). Subjects who had three successive casual blood pressure measurements above the 95th percentile were excluded.

RESULTS

By body mass index, 148 (10.7%) subjects were obese, 182 (13.1%) overweight and 359 (25.9%) having larger WC (≥85th percentiles). MH was diagnosed in 217 subjects (15.7%). Subjects with larger WC or obesity were significantly associated with higher 24-h daytime and night-time systolic blood pressure (≥95th percentile) (odds ratios from 1.84 to 2.09 and from 2.07 to 3.54 for larger WC and obese respectively, all P < 0.05) as well as 24-h DBP for larger WC (odds ratio = 2, P = 0.015) than normal subjects adjusted by sex, age and height.

CONCLUSION

Waist circumference and body mass index are independent risk factors of childhood and adolescent MH. WC appears a significant associated factor of elevated 24-h DBP in children aged 8-17 years.

Prevalence of overweight and obesity and their associations with blood pressure among children and adolescents in Shandong, China

BACKGROUND

Obesity and high blood pressure (BP) are public health problems all over the world. Some studies have reported a positive association between them in children and adolescents. The purpose of this study was to assess the prevalence of overweight and obesity and their associations with BP among school children and adolescents in Shandong, an important province in eastern China.

METHODS

In 2011, we conducted a cross-sectional population-representative survey in Shandong, China. A total of 4 898 children and adolescents aged 6-17 years were randomly selected from 140 counties/districts using a multistage random cluster sampling. Weight, height and BP were measured by a trained physician or pediatrician, and information about age, gender and place of residence was obtained using questionnaires. Obesity and high BP were defined according to age- and gender-specific Chinese reference data for children.

RESULTS

A total of 4 898 (100%) children and adolescents provided complete information. The prevalence of overweight, obesity and overweight plus obesity were 10.9%, 8.7% and 19.6%, respectively. Boys were more likely to be overweight or obese than girls (P < 0.05 for overweight; P < 0.001 for obesity). The prevalence of overweight plus obesity was highest among children aged 6-11 years (22.3%). BP and the prevalence of high BP increased with increasing body mass index (BMI). With age and sex adjusted, odds ratios (ORs) for high BP were [OR 2.2;95% CI 1.7-2.8) in overweight and [OR 3.6;95% CI 2.6-4.9] in obese children.

CONCLUSION

The representative survey confirms high prevalence of overweight and obesity among children and adolescents in Shandong. Childhood obesity is a strong risk factor for high BP. Intervention programs should be implemented to combat the growing obesity epidemic.

Anthropometric measures and blood pressure in school children

OBJECTIVE

To investigate the association of blood pressure and body mass index, waist circumference, waist-to-height ratio and triceps skinfold, in children and adolescents in Curitiba, state of Paraná, Brazil.

METHODS

Cross-sectional study with a random sample of 1,441 students from public schools, aged from 10 to 16 years (655 boys and 786 girls). The following indicators were assessed: weight, height, waist circumference, triceps skinfold, systolic and diastolic blood pressures, pubertal stage, and socioeconomic status. Pearson correlation tests and multivariate logistic regression were used, considering p<0.05.

RESULTS

We found weak correlations among all the anthropometric parameters and systolic and diastolic levels, with coefficients values ranging from 0.18 to 0.28 (p<0.001). In multivariate analysis, only body mass index [odds ratio (OR)=2.9; 95% confidence interval (95%CI) 1.9-4.5] and triceps skinfold (OR=1.9; 95%CI 1.3-3.1) were found as predictors of high blood pressure, regardless of abdominal adiposity, sexual maturation and socioeconomic status.

CONCLUSION

Total body adiposity seems to be a better predictor of high blood pressure risk than abdominal fat in this population.

Oral contraceptive use in girls and alcohol consumption in boys are associated with increased blood pressure in late adolescence

AIMS

Lifestyle behaviours established during adolescence may adversely affect blood pressure (BP) and contribute to gender differences in cardiovascular risk in adulthood. We aimed to assess the association of health behaviours with BP in adolescents, using data from the Western Australian Pregnancy (Raine) Study.

METHODS

Cross-sectional analysis on 1248 Raine Study adolescents aged 17 years, to examine associations between lifestyle factors and BP.

RESULTS

Boys had 8.97 mmHg higher systolic BP, as compared with girls. The 30% of girls using oral contraceptives (OC) had 3.27 and 1.74 mmHg higher systolic and diastolic BP, respectively, compared with non-users. Alcohol consumption in boys, increasing body mass index (BMI) and the sodium-potassium ratio were associated with systolic BP. We found a continuous relationship between BMI and systolic BP in both genders; however, the gradient of this relationship was significantly steeper in boys, compared with girls not taking OC. In boys, systolic BP was 5.7 mmHg greater in alcohol consumers who were in the upper quartile of BMI and the urinary sodium-potassium ratio compared with teetotallers in the lowest quartile. In girls, systolic BP was 5.5 mmHg higher in those taking OC, in the highest BMI and urinary sodium-potassium ratio quartile as compared to those not taking the OC pill and in the lowest quartile.

CONCLUSION

In addition to gender-related differences in the effects of adiposity on BP, we found lifestyle-related health behaviours such as high salt intake for both sexes, consumption of alcohol in boys, and OC use in girls were important factors associated with BP measurements in late adolescence. This suggests that gender-specific behavioural modification in adolescence may prevent adult hypertension.

Blood pressure and obesity among adolescents: a school-based population study in China

BACKGROUND

There is little information regarding the obesity epidemical situation and risk factors of childhood hypertension (HTN) in China. The present study aimed to determine the prevalence of HTN/prehypertension (PHTN), as well as the associated risk factors, among adolescents in Changsha city, China.

METHODS

A total of 88,974 adolescents from 49 middle schools in Changsha city between 12 and 17 years of age were examined during 2009. Body weight, height, and blood pressure (BP) were measured in all adolescents. HTN and PHTN were defined according to sex- and age-specific Chinese reference data. Overweight and obesity were also defined according to sex- and age-specific Chinese reference data.

RESULTS

It was determined that the prevalence of PHTN and HTN were 7.2 and 3.1%, respectively. Furthermore, 14.6% of male adolescents were overweight and 7.0% were obese, whereas 8.6% of female adolescents were overweight and 2.9% were obese. The risk ratio (RR) of HTN were significantly higher in overweight (RR: 2.8, 95% confidence interval (CI): 2.6-3.2) and obese (RR: 8.7, 95% CI: 8.1-9.5) adolescents adjusted for age, sex, and height.

CONCLUSIONS

Chinese reference data were used to evaluate BP and body mass index (BMI) of children and adolescents. Higher prevalence of HTN was associated with higher BMI percentiles. Being overweight or obese markedly increased the risk of both HTN and PHTN among adolescents between 12 and 17 years of age in Changsha city, China.

Body fat and blood pressure: comparison of blood pressure measurements in Chinese children with different body fat levels

Children in China are experiencing a rapid increase in the prevalence of obesity, which is associated with hypertension. To compare the effect of body fat on blood pressure (BP) with that of the normal physical growth, we compared BP levels in Chinese children with different body fat levels. In the present population-based study, 13 972 children in the highest-skinfold-thickness-quartile group were individually matched to 13 972 children in the lowest-skinfold-thickness-quartile group by height and weight. Similarly, 5103 children in the highest-waist-circumference-quartile group were matched to the same number of children in the lowest-waist-circumference-quartile group. The high- and low-fat groups had similar height and weight but the high-fat group had significantly higher skinfold and waist circumference measurements. The differences in systolic BP (SBP) between the high- and low-skinfold-thickness groups were small: 0·01 (95 % CI − 0·41, 0·44) mmHg in boys and 0·20 (95 % CI − 0·15, 0·54) mmHg in girls. The differences in diastolic BP (DBP) were also small (0·39 and 0·38 mmHg for boys and girls, respectively) but were statistically significant. The differences in both SBP and DBP between the high- and low-waist-circumference groups were small but not statistically significant. For a given body size as measured by height and weight, relative body fat had little impact on BP levels in these children. Fat mass and lean mass may have a similar quantitative impact on BP in healthy-weight children.

Association of adipokines with blood pressure in rural Chinese adolescents

Previous research has demonstrated that adipokines influence blood pressure (BP). Limited data exist in healthy adolescents, who are in a critical period for preventing the development of high BP. This study investigated the association of leptin, adiponectin and the leptin-to-adiponectin ratio (LAR) with BP in rural Chinese adolescents. This report included 1245 adolescents (average body mass index: 19.3 kg m(-2)) aged 13-21 years from an established twin cohort. We examined gender-specific associations between plasma adipokines and BP, with adjustment for measures of adiposity and insulin resistance (IR). We estimated the genetic contribution to adipokines using the twin design and Cholesky decomposition models. There was no correlation between leptin and adiponectin levels. Leptin was positively associated with systolic blood pressure (SBP) in males and diastolic blood pressure in females, but the association disappeared after adjusting for adiposity and IR. LAR was positively associated with SBP (β(s.e.): 1.94(0.45)), P<0.01), adiponectin was negatively associated with SBP (β(s.e.): -2.18(0.63)), P<0.001) only in males, and such associations were independent of adiposity and IR. A test of gender × adiponectin interaction was significant (P=0.01). Heritability estimation showed that both environmental and genetic factors contribute to variance in adipokines. In these relatively lean Chinese adolescents, leptin was positively associated with BP in both genders, but was adiposity/IR dependent. Adiponectin was negatively associated with SBP in males, independent of adiposity/IR.

High blood pressure in obese and nonobese Japanese children: blood pressure measurement is necessary even in nonobese Japanese children

Background

Although the prevalences of obesity and hypertension (HT) are increasing in children, there have been few epidemiological studies of HT in Japanese children. We evaluated the prevalences of HT and high-normal blood pressure (HNBP), and examined the relationship between blood pressure (BP) and body mass index (BMI), in Japanese children.

Methods

The subjects of this study were 2420 children living in the town of Ina, Saitama Prefecture, Japan during the period from 2006 through 2008. Body height, weight, and BP were measured. HT and HNBP were defined according to the HT criteria for Japanese children. Children with HNBP or HT were defined as having high blood pressure (HBP).

Results

The prevalences of HBP were 15.9% and 15.8% in fourth-grade boys and girls, respectively, and 11.1% and 10.8% in seventh-grade boys and girls, respectively. Irrespective of sex or grade level, a higher BMI was associated with a higher prevalence of HBP (P < 0.001). When compared with the <50th percentile BMI category, the crude odds ratios (ORs) were statistically significant for the 75th to 84th percentile category in fourth-grade boys (OR: 4.54, 95% CI: 2.36–8.76), the ≥95th percentile in fourth-grade girls (13.29, 5.93–29.77), the 85th to 94th percentile (3.16, 1.46–6.84) in seventh-grade boys, and the ≥95th percentile (7.96, 3.18–19.93) in seventh-grade girls.

Conclusions

BMI was associated with HBP in Japanese school children. In addition, some children in the lower BMI categories also had HBP.

Countries in transition: underweight to obesity non-stop?

The rise in childhood overweight and obesity in less developed countries and those with transitional economies is widely recorded. In many cases, this increase in overweight is occurring in societies where levels of under-nutrition remain high. Overweight particularly affects children in affluent families and urban families and is usually much less in rural areas. Changes such as the availability of more Western-style foods, the prevalence of snacking, a decline in physical activity, less sleep and the inactivity associated with watching television may all be contributing to the rise of overweight. The complications of overweight/obesity are already being seen in some affected children. Efforts to treat and prevent overweight in children are needed urgently if the appalling levels of overweight currently seen in the well established market economies of Europe and North America are to be avoided by less developed and transitional economies.

Adiposity, serum lipid levels, and allergic sensitization in Chinese men and women

BACKGROUND

Obesity and allergic diseases have increased dramatically in recent decades. Although adiposity has been associated with asthma, associations with allergic sensitization have been inconsistent.

OBJECTIVE

To examine the association of adiposity and lipid profiles with allergic sensitization.

METHODS

This study included 1187 rural Chinese twins (653 men) age 18 to 39 years, with skin prick tests, anthropometric and dual-energy x-ray absorptiometry-assessed adiposity measures, and lipid assessments. Allergic sensitization was defined as positive SPT to >/=1 allergen (9 foods and 5 aeroallergens tested). We applied sex-stratified generalized estimating equations to assess the association of adiposity and serum lipids with allergic sensitization, and structural equation models to estimate the genetic/environmental influences on any observed associations.

RESULTS

Men had lower percent body fat (% BF) (13.9% vs. 28.8%) but higher rates of allergic sensitization (56.2% vs 36.7%) than women. Men in the highest %BF quartile were 2.1 times more likely to be sensitized than the lowest quartile (95% CI, 1.3-3.5; P trend = .003). In men, the risk of allergic sensitization increased with high-density lipoprotein (HDL) <40 mg/dL (odds ratio = 4.0; 95% CI, 1.8-9.2) and higher low-density lipoprotein quartiles (P trend = .007). This appeared to be partially explained by shared genetic factors between serum lipid levels and allergic sensitization. In females, lower HDL was associated with increased risk of allergic sensitization.

CONCLUSION

In this relatively lean Chinese population, higher %BF, lower HDL and higher LDL were associated with greater risk of allergic sensitization, most notable in men. The observed associations among adiposity, serum lipids, and allergic sensitization in men appear to be partially explained by common genetic influences on these traits.