Studies of blood pressures in children, ages 5-14 years, in a total biracial community: the Bogalusa Heart Study

Going from Primary to Primordial Prevention: Is the Juice Worth the Squeeze?

PURPOSE OF REVIEW

While primary prevention strategies target individuals who are at high risk of cardiovascular disease, there is rising interest towards primordial prevention that focuses on preventing the development of risk factors upstream of disease detection. Therefore, we review the advantages of primordial prevention interventions on minimizing future cardiovascular events.

RECENT FINDINGS

Primordial prevention of atherosclerotic cardiovascular disease involves behavioral, genetic, and environmental strategies, starting from fetal/infant health and continuing throughout childhood and young adulthood. Early interventions focusing on modifiable risk factors such as physical inactivity, non-ideal body weight, smoking, and environmental pollutants are important towards preventing the initial occurrence of risk factors such as hypertension, dyslipidemia, and diabetes to ultimately reduce cardiovascular disease. Implementing primordial prevention strategies early on in life can minimize cardiovascular events and lead to healthy aging in the population. Future studies can further evaluate the effectiveness of various primordial prevention strategies.

The association between the urinary chromium and blood pressure: a population-based study

BACKGROUND AND AIM

The impact of trace elements and heavy metals on human health has attracted widespread attention. However, the correlation between urinary chromium concentrations and blood pressure remains unclear and inadequately reported, and the aim of this study was to investigate the relationship between urinary chromium concentrations and blood pressure in adults in the United States (US).

METHODS

We utilized data from the National Health and Nutrition Examination Survey (NHANES) 2017-2018 for this study. Multivariate logistic regression and multivariate linear regression were used to explore the association of urinary chromium concentrations with hypertension and blood pressure. Additionally, we also performed subgroup analysis and restricted cubic splines (RCS).

RESULTS

A total of 2958 participants were enrolled in this study. The overall mean systolic blood pressure and diastolic blood pressure were 123.98 ± 0.60, 72.66 ± 0.57 mmHg, respectively. The prevalence of hypertension was found in 41.31% of the whole participants. In the fully adjusted model, we did not observe a correlation between urinary chromium concentrations and the risk of hypertension and systolic blood pressure. However, we found a negative association between urinary chromium concentrations and diastolic blood pressure. In subgroup analysis, we observed a positive association between urinary chromium and the risk of hypertension among participants older than 60 years of age and those who were Non-Hispanic Black. The interaction term highlighted the influence of age and race on this positive association. We also found a negative association of urinary chromium with diastolic blood pressure in male, participants who were current smokers, overweight, and other races, as well as those without alcohol use and anti-hypertensive drug use. However, the interaction term only revealed the influence of alcohol consumption on the negative association.

CONCLUSION

Our study suggested that urinary chromium concentrations may show a negative association with diastolic blood pressure and this association was significantly dependent on alcohol consumption. Besides, a positive association between urinary chromium and the risk of hypertension was also found among participants older than 60 years of age and those who were Non-Hispanic Black.

Fat-free mass may play a dominant role in the association between systolic blood pressure and body composition in children and adolescents

Systolic blood pressure (SBP) is significantly associated with body composition in children and adolescents. However, which one of the components of body composition is the dominant contributor to SBP in children and adolescents remains unclear. We, therefore, aimed to determine the dominant contributor to SBP among components of body composition in a large cohort of American children and adolescents derived from the National Health and Nutrition Examination Survey with cross-sectional analysis. In total, 13 618 children and adolescents (median age 13 years; 6107 girls) with available data on whole-body dual-emission X-ray absorptiometry measurements were included. Multiple linear regression showed that SBP was associated with higher total fat-free mass in boys (β = 0·49, P < 0·001) and girls (β = 0·47, P < 0·001) and with higher total fat mass only in boys (β = 0·12, P < 0·001) after adjustment for covariates. When taking fat distribution into consideration, SBP was associated with higher trunk fat mass (boys: β = 0·28, P < 0·001; girls: β = 0·15, P < 0·001) but negatively associated with leg fat mass (Boys: β = -0·14, P < 0·001; Girls: β = -0·11, P < 0·001), in both boys and girls. Dominance analysis showed that total fat-free mass was the dominant contributor to SBP (boys: 49 %; girls: 55·3 %), followed by trunk fat mass (boys: 32·1 %; girls: 26·9 %); leg fat mass contributed the least to SBP in boys (18·9 %) and girls (17·8 %). Our findings indicated that total fat-free mass was not only associated with SBP but also the most dominant contributor to SBP variation in American children and adolescents.

Salty Subjects: Unpacking Racial Differences in Salt-Sensitive Hypertension

PURPOSE OF REVIEW

To review underlying mechanisms and environmental factors that may influence racial disparities in the development of salt-sensitive blood pressure.

RECENT FINDINGS

Our group and others have observed racial differences in diet and hydration, which may influence salt sensitivity. Dietary salt elicits negative alterations to the gut microbiota and immune system, which may increase hypertension risk, but little is known regarding potential racial differences in these physiological responses. Antioxidant supplementation and exercise offset vascular dysfunction following dietary salt, including in Black adults. Furthermore, recent work proposes the role of racial differences in exposure to social determinants of health, and differences in health behaviors that may influence risk of salt sensitivity. Physiological and environmental factors contribute to the mechanisms that manifest in racial differences in salt-sensitive blood pressure. Using this information, additional work is needed to develop strategies that can attenuate racial disparities in salt-sensitive blood pressure.

Non-alcoholic fatty liver disease mediates the effect of obesity on arterial hypertension

BACKGROUND

It has been consistently shown that obesity contributes directly to arterial hypertension and cardiovascular disease (CVD), independently of other risk factors. Likewise, non-alcoholic fatty liver disease (NAFLD) is acknowledged as a contributor and a risk enhancer for CVD.

OBJECTIVES

We tested the hypothesis of a causal role of NAFLD in the effect of obesity on arterial hypertension.

METHODS

Using causal mediation analysis, we quantified the magnitude of the body mass index (BMI) effect on arterial hypertension and CV-traits mediated by NAFLD. First, we analysed data from 1348 young adults in the Bogalusa Heart Study (BHS), a cohort aimed at assessing the natural history of CVD. Then, we used data from 3359 participants of the National Health and Nutrition Examination Survey (2017-2018 cycle, NHANES) to replicate the findings.

RESULTS

We found that roughly 92% of the effects of BMI on arterial hypertension in the BHS and 51% in the NHANES population are mediated by NAFLD. In addition, indirect effects of BMI on systolic (SBP) and diastolic (DBP) blood pressure, and heart rate (HR) through NAFLD explained up to 91%, 93%, and 100% of the total effect, respectively, in the BHS. In the NHANES survey, indirect effects of BMI through NAFLD on CV traits explain a significant proportion of the total effects (SBP = 60.4%, HR = 100%, and pulse pressure = 88%).

CONCLUSION

NAFLD mediates a substantial proportion of the effect of obesity on the presence of hypertension and CV-parameters independently of relevant covariates. This conclusion has implications for clinical management.

Primordial prevention: Reducing consumption of sugar-sweetened beverages in racial/ethnic populations

Beyond pharmacotherapy in adulthood, primordial prevention in United States (U.S.) children and adolescents is needed to avoid the upcoming tsunami of cardiometabolic and cardiovascular disease (CVD). Healthcare disparities were unmasked by the disparate morbidity and mortality of COVID-19 in racial/ethnic populations, especially in persons with obesity, diabetes, and CVD. One potential successful strategic improvement of childhood cardiovascular health is to reduce sugar consumption in early life as CVD is the number one cause of death in patients with Type 2 diabetes (T2D). Furthermore, cardiologists treat more patients with T2D than endocrinologists. This commentary challenges cardiovascular specialists and other clinicians to address the increasing burden of cardiometabolic and CVD in adults, especially in racial/ethnic populations, by supporting primordial prevention in childhood.

Racial and ethnic disparities in cardiometabolic disease and COVID-19 outcomes in White, Black/African American, and Latinx populations: Physiological underpinnings

Coronavirus disease 2019 (COVID-19) is a highly contagious respiratory illness caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) that began spreading globally in late 2019. While most cases of COVID-19 present with mild to moderate symptoms, COVID-19 was the third leading cause of mortality in the United States in 2020 and 2021. Though COVID-19 affects individuals of all races and ethnicities, non-Hispanic Black and Hispanic/Latinx populations are facing an inequitable burden of COVID-19 characterized by an increased risk for hospitalization and mortality. Importantly, non-Hispanic Black and Hispanic/Latinx adults have also faced a greater risk of non-COVID-19-related mortality (e.g., from cardiovascular disease/CVD) during the pandemic. Contributors to the racial disparities in morbidity and mortality during the pandemic are multi-factorial as we discuss in our companion article on social determinants of health. However, profound racial variation in the prevalence of CVD and metabolic diseases may serve as a key driver of worse COVID-19-related and non-COVID-19-related health outcomes among racial and ethnic minority groups. Within this review, we provide data emphasizing the inequitable burden of CVD and metabolic diseases among non-Hispanic Black and Hispanic/Latinx populations. We also discuss the pathophysiology of these conditions, with a focus on how aberrant physiological alterations in the context of CVD and metabolic diseases manifest to increase susceptibility to severe COVID-19.

Circulating Levels of the Heparan Sulfate Proteoglycan Syndecan-4 Positively Associate with Blood Pressure in Healthy Premenopausal Women

Syndecans (SDCs) are transmembrane proteins that are present on most cell types where they play a role in multiple physiological processes, including cell-matrix adhesion and inflammation. Growing evidence suggests that elevated levels of both shed SDC1 and SDC4 are associated with hypertension and cardiovascular diseases, but their relationships with cardiovascular risk factors in healthy individuals are unknown. The primary objective of this study was to investigate whether serum levels of SDC4 and SDC1 were associated with body composition, hemodynamic parameters, pro-inflammatory cytokine concentrations, and urinary noradrenaline and dopamine levels in healthy women (17 African American and 20 European American) between the ages of 20 and 40 years old. Univariate analyses revealed only a significant (p < 0.05) inverse correlation between serum SDC1 and body fat percentage. On the other hand, serum SDC4 was positively correlated with systolic blood pressure, diastolic blood pressure, and urinary levels of noradrenaline and dopamine. Serum SDC4 was also a significant predictor of systolic blood pressure in a multivariate regression model that included fat-free mass and urinary dopamine levels as significant independent variables. The result did not change even adjusting for race. Our findings indicate that SDC4 has an important role in the physiological regulation of blood pressure.

The Influence of Maturity Status on Resting Energy Expenditure, Body Composition and Blood Pressure in Physically Active Children

Peak height velocity (PHV) is the period where the maximum rate of growth occurs. The moment the sports player reaches PHV can be estimated by monitoring the growth of body structures. The aim of this study was to assess changes in resting energy expenditure (REE), body composition and blood pressure in young, male soccer players between the pre-PHV, circa-PHV and post-PHV periods. This transverse study was conducted among 184 children aged 9 to 17 and included measurements of the resting energy expenditure (REE) using indirect calorimetry, body composition (bioimpedance) and blood pressure (sphygmomanometer). In addition, births in each quartile were analyzed. Children in the pre-PHV group had significantly lower REE values compared to the other two groups (p < 0.0001). The differences in the value of the REE between the children in the circum and post groups were not statistically significant. Additionally, the fat-free mass was significantly lower in the pre-PHV period compared to the other two periods (p < 0.0001), and the same relationship concerned the z-score body mass index (BMI) and systolic blood pressure. Early-born players were overrepresented (p < 0.05).

Muscle mass is the main somatic growth indicator associated with increasing blood pressure with age in children and adolescents

Studies have shown that lean mass must be an important determinant of blood pressure value in children and adolescents. The absence of adjustment for the collinearity between lean and fat mass (FM), restricted age span, and lack of separate analysis by sex leave a gap in the literature. This study determined direct and indirect effects of the somatic growth indicators linked to the association between age and systolic blood pressure (SBP) in boys and girls. This is a cross-sectional study comprising 1,510 participants (6-18 years). Path analysis was used to test a model in which the association between age and SBP would have a direct and independent component, but also indirect mediating paths through muscle mass (MM), FM, and height. There was no significant association between age and SBP (unstandardized β ± SE) for both girls (0.072 ± 0.236, P = .761) and boys (0.238 ± 0.264, P = .368). Height was not a mediator for the association between age and SBP in both girls (-0.291 ± 0.156, P = .062) and boys (-0.015 ± 0.187, P = .935). Mediating effect of MM was significant for both girls (0.909 ± 0.137, P < .001) and boys (1.341 ± 0.161, P < .001), whereas mediating path through FM was significant only for boys (0.069 ± 0.023, P = .003). In conclusion, muscle mass was the strongest somatic growth indicator associated with the blood pressure value in children and adolescents. Further increase in body fat mass may affect systolic blood pressure more in boys than in girls.

Oscillometric blood pressure profile of adolescent secondary school students in Abakaliki metropolis

Context

Adolescence is characterized by a tremendous pace in growth, biological, and psychosocial changes. This may translate to rapid increases in anthropometric parameters and indulgence in youth risk behaviors, and these are the risk factors for arterial hypertension (HTN).

Aim

This study aimed to determine the oscillometric blood pressure (BP) profile of apparently healthy secondary school adolescents in Abakaliki metropolis and its relationship with sex and anthropometric variables.

Subjects and Methods

This multistage process selected 2401 students among those aged 10-19 years spanning from August 2015 to January 2016. BP was measured using the oscillometric method. Information on modifiable risk factors for HTN was obtained. Anthropometric parameters were measured. Data were analyzed with Student's t-test, analysis of variance, and correlation analysis.

Results

The mean age (years) of the study population was 15.12 ± 2.29. The mean systolic BP (SBP) and diastolic BP (DBP) were 106.72 ± 11.37 mmHg and 63.60 ± 7.34 mmHg, respectively. Females had significantly higher mean DBP but with no significant gender difference in mean SBP. The means of anthropometric parameters were 49.19 ± 10.28 kg, 1.54 ± 0.10 m, and 20.46 ± 2.86 kg/m2 for weight, height, and body mass index, respectively, and all showed significant gender differences, with females having higher values except for height. A relatively low rate of indulgence in alcohol use compared to another study in the same region as well as a significant association of alcohol use among those found to have HTN was noted. The prevalence of HTN was 4.6%, which was significantly higher in females.

Conclusions

Routine BP monitoring is recommended for adolescents, especially those with prevailing risk factors including a family history of HTN, obesity, and substance and alcohol misuse. Early detection will help in mitigating the effect of these cardiovascular risk factors.

Diagnosis, Evaluation, and Management of High Blood Pressure in Children and Adolescents

Systemic hypertension is a major cause of morbidity and mortality in adulthood. High blood pressure (HBP) and repeated measures of HBP, hypertension (HTN), begin in youth. Knowledge of how best to diagnose, manage, and treat systemic HTN in children and adolescents is important for primary and subspecialty care providers.

OBJECTIVES

To provide a technical summary of the methodology used to generate the 2017 "Clinical Practice Guideline for Screening and Management of High Blood Pressure in Children and Adolescents," an update to the 2004 "Fourth Report on the Diagnosis, Evaluation, and Treatment of High Blood Pressure in Children and Adolescents."

DATA SOURCES

Medline, Cochrane Central Register of Controlled Trials, and Excerpta Medica Database references published between January 2003 and July 2015 followed by an additional search between August 2015 and July 2016.

STUDY SELECTION

English-language observational studies and randomized trials.

METHODS

Key action statements (KASs) and additional recommendations regarding the diagnosis, management, and treatment of HBP in youth were the product of a detailed systematic review of the literature. A content outline establishing the breadth and depth was followed by the generation of 4 patient, intervention, comparison, outcome, time questions. Key questions addressed: (1) diagnosis of systemic HTN, (2) recommended work-up of systemic HTN, (3) optimal blood pressure (BP) goals, and (4) impact of high BP on indirect markers of cardiovascular disease in youth. Once selected, references were subjected to a 2-person review of the abstract and title followed by a separate 2-person full-text review. Full citation information, population data, findings, benefits and harms of the findings, as well as other key reference information were archived. Selected primary references were then used for KAS generation. Level of evidence (LOE) scoring was assigned for each reference and then in aggregate. Appropriate language was used to generate each KAS based on the LOE and the balance of benefit versus harm of the findings. Topics that could not be researched via the stated approach were (1) definition of HTN in youth, and (2) definition of left ventricular hypertrophy. KASs related to these stated topics were generated via expert opinion.

RESULTS

Nearly 15 000 references were identified during an initial literature search. After a deduplication process, 14 382 references were available for title and abstract review, and 1379 underwent full text review. One hundred twenty-four experimental and observational studies published between 2003 and 2016 were selected as primary references for KAS generation, followed by an additional 269 primary references selected between August 2015 and July 2016. The LOE for the majority of references was C. In total, 30 KASs and 27 additional recommendations were generated; 12 were related to the diagnosis of HTN, 13 were related to management and additional diagnostic testing, 3 to treatment goals, and 2 to treatment options. Finally, special additions to the clinical practice guideline included creation of new BP tables based on BP values obtained solely from children with normal weight, creation of a simplified table to enhance screening and recognition of abnormal BP, and a revision of the criteria for diagnosing left ventricular hypertrophy.

CONCLUSIONS

An extensive and detailed systematic approach was used to generate evidence-based guidelines for the diagnosis, management, and treatment of youth with systemic HTN.

Cumulative Incidence of Hypertension by 55 Years of Age in Blacks and Whites: The CARDIA Study

BACKGROUND

Blacks have higher blood pressure levels compared with whites beginning in childhood. Few data are available on racial differences in the incidence of hypertension from young adulthood through middle age.

METHODS AND RESULTS

We calculated the cumulative incidence of hypertension from age 18 to 55 years among participants in the CARDIA (Coronary Artery Risk Development in Young Adults) study. Incident hypertension was defined by the first visit with mean systolic blood pressure ≥130 mm Hg, mean diastolic blood pressure ≥80 mm Hg, or self-reported use of antihypertensive medication. Among 3890 participants without hypertension at baseline (aged 18-30 years), cumulative incidence of hypertension by age 55 years was 75.5%, 75.7%, 54.5%, and 40.0% in black men, black women, white men, and white women, respectively. Among participants with systolic blood pressure/diastolic blood pressure <110 and 70, 110 to 119/70 to 74, and 120 to 129/75 to 79 mm Hg at baseline, blacks were more likely than whites to develop hypertension: multivariable-adjusted hazard ratios 1.97 (95% confidence interval, 1.65, 2.35), 1.80 (95% confidence interval, 1.52, 2.14), and 1.59 (95% confidence interval, 1.31, 1.93), respectively. Parental history of hypertension and higher body mass index, serum uric acid, and systolic blood pressure/diastolic blood pressure categories were associated with a higher risk for hypertension among blacks and whites. A higher Dietary Approaches to Stop Hypertension diet adherence score was associated with a lower risk for hypertension in blacks and whites.

CONCLUSIONS

Regardless of blood pressure level in young adulthood, blacks have a substantially higher risk for hypertension compared with whites through 55 years of age.

Prevalence of Primary Hypertension and Risk Factors in Grade XII Learners in KwaZulu-Natal, South Africa

Hypertension in childhood leads to hypertension in adult life, the strongest risk factor being obesity. This study determined the prevalence of primary hypertension and its risk factors in Grade XII learners in KwaZulu-Natal, South Africa, from March 2016 to June 2017. Weight, height, body mass index (BMI), random finger prick cholesterol and glucose, and spot urine for an albumin : creatinine ratio were measured. An average of three separate blood pressure readings taken was at least 5 minutes apart. Five hundred and sixty-four learners had weight, height, and BMI; 536 had random blood glucose; and 545 had cholesterol and random spot urine albumin : creatinine ratios measured. Prehypertension was detected in 168 (29.7%) and hypertension in 77 (13.7%) of learners. Ninety (15.9%) were overweight and 75 (13,3%) were obese. Hypercholesterolaemia was present in 58 (10.8%) and a high spot random urine albumin : creatinine ratio in 5 (1.0%). None had a high blood glucose level. Both prehypertension and hypertension in all learners showed a significant increase with increasing BMI. Six (1.0%) learners had metabolic syndrome. Female learners in other racial groups (defined as Indian, mixed race, and White learners), overweight, and obese learners showed significantly higher rates of hypercholesterolaemia. We showed overweight and obesity as risk factors for prehypertension and hypertension. This presages the need for an appropriate diet and adequate exercise in a child's school career.

Early sexual experience and hypertension in US adults: results from the National Health and Nutrition Examination Survey 2001-2016

OBJECTIVES

We examined whether the early initiation of sexual activity is associated with hypertension in US adults, and whether the timing of first menstruation is meaningful in regard of this association. We also assessed the effect modification by ethnicity.

METHODS

Using data from 2001 to 2016 National Health and Nutrition Examination Survey, we included 39 788 women. The association of age at the first sexual intercourse (FSI) and hypertension (SBP ≥ 130 mmHg or DBP ≥ 80 mmHg) was examined using multivariate logistic regression. Effect modification by ethnicity was assessed through a cross-product interaction term between age at FSI and ethnicity.

RESULTS

Among women with FSI after their first menstruation, the odds of hypertension decrease by 20% [95% confidence interval (CI) -27 to -13%] in those who experienced FSI after 19 years of age, relative to those with FSI before 19 years of age. Ethnicity significantly modified the inverse association between age at FSI and hypertension (P value for interaction: 0.0003). Among non-Hispanic white, having FSI aged at least 19 years reduced the odds of hypertension by 34% (95% CI -41 to -27%). Turning to Latina women, the FSI before 19 years of age and before first menstruation resulted to a marked increase in the odds of hypertension [odds ratio = 1.38 (95% CI 1.15-1.65)]. In non-Hispanic black, the age at FSI was not linked to hypertension.

CONCLUSION

The FSI before 19 years of age is associated with hypertension during adulthood in US non-Hispanic white and Hispanic women, but not in non-Hispanic black.

Race and Sex Differences of Long-Term Blood Pressure Profiles From Childhood and Adult Hypertension: The Bogalusa Heart Study

This study aims to characterize longitudinal blood pressure (BP) trajectories from childhood in black-white and sex groups and examine the association between childhood level-independent trajectories of BP and adult hypertension. The longitudinal cohort consisted of 2732 adults who had body mass index and BP measured 4 to 15 times from childhood (4-19 years) to adulthood (20-51 years). Model-estimated levels and linear slopes of BP and body mass index at childhood age points were calculated at 1-year intervals using the growth curve parameters and their first derivatives, respectively. Linear and nonlinear curve parameters differed significantly between race-sex groups; BP levels showed race and sex differences 15 years of age onward. Hypertensives had higher long-term BP levels than normotensives in race-sex groups. Although linear and nonlinear slope parameters of BP were race and sex specific, they differed consistently, significantly between hypertension and normotension groups. BP trajectories during young adulthood (20-35 years) were significantly greater in hypertensives than in normotensives; however, the trajectories during middle-aged adulthood (36-51 years) were significantly smaller in hypertensives than in normotensives. Level-independent linear slopes of systolic BP showed significantly negative associations (odds ratio=0.50≈0.76; P<0.001) during prepuberty period (4-11 years) but significantly positive associations (odd ratio=1.44≈2.80, P<0.001) during the puberty period (13-19 years) with adult hypertension, adjusting for covariates. These associations were consistent across race-sex groups. These observations indicate that adult hypertension originates in childhood, with different longitudinal BP trajectory profiles during young and middle-aged adulthood in black-white and sex groups. Puberty is a crucial period for the development of hypertension in later life.

Race and Obesity in Adolescent Hypertension

BACKGROUND AND OBJECTIVES

The overall prevalence of essential hypertension in adolescents may be growing. Differences in blood pressure (BP) are well established in adults, but are less clear in adolescents. We hypothesize that the prevalence of hypertension differs by race/ethnicity among adolescents at school-based screenings.

METHODS

We performed school-based BP screening in over 20 000 adolescents from 2000 to 2015. Race/ethnicity was self-reported. Height and weight were measured to determine BMI, and BP status was confirmed on 3 occasions to diagnose sustained hypertension according to Fourth Working Group Report criteria.

RESULTS

We successfully screened 21 062 adolescents aged 10 to 19 years (mean, 13.8 years). The final prevalence of sustained hypertension in all subjects was 2.7%. Obesity rates were highest among African American (3.1%) and Hispanic (2.7%) adolescents. The highest rate of hypertension was seen in Hispanic (3.1%), followed by African American (2.7%), white (2.6%), and Asian (1.7%) adolescents (P = .019). However, obese white adolescents had the highest prevalence of sustained hypertension (7.4%) compared with obese African American adolescents (4.5%, P < .001). At lower BMI percentiles (<60th percentile), Hispanic adolescents actually had the lowest predicted prevalence of hypertension among the 4 groups.

CONCLUSIONS

The prevalence of hypertension varies among different race/ethnicities. Although obesity remains the strongest predictor of early hypertension, the strength of this relationship is intensified in Hispanic and white adolescents, whereas it is lessened in African American adolescents.

HIPERTENSÃO EM ESTUDANTES DA REDE PÚBLICA DE VITÓRIA/ES: INFLUÊNCIA DO SOBREPESO E OBESIDADE

RESUMO Introdução: Pesquisas demonstram que a obesidade pode ter início na infância. Além disso, o excesso de peso presente em 50% na infância é fator preditor da obesidade na vida adulta. As consequências são preocupantes pela associação com diversas comorbidades, entre elas, a hipertensão arterial. Estudos mostram que crianças obesas apresentam risco superior de hipertensão arterial em relação às não obesas. Objetivo: Identificar a prevalência de hipertensão arterial e sua relação com o sobrepeso e obesidade em crianças e adolescentes estudantes da rede pública do município de Vitória, ES, Brasil. Foram estudados 477 alunos, com idade entre 7 e 17 anos, sendo 42,56% e 57,44% dos gêneros masculino e feminino, respectivamente, selecionados por meio de amostragem estratificada por conglomerados . Métodos: Na análise do perfil antropométrico foram utilizados: percentual de gordura por meio de medida de dobras cutâneas e índice de massa corporal (IMC). Além disso, foi realizada aferição da pressão arterial para classificação da hipertensão arterial. Resultados: Os resultados mostram nos estudantes de Vitória, ES, com sobrepeso, valores pressóricos elevados (limítrofes e hipertensos 1 e 2), representando nos gêneros masculino e feminino 21,1% (PAS: 112 ± 10,4 mmHg e PAD: 65,6 ± 8,91 mmHg) e 19,2% (PAS: 108 ± 12,1 mmHg e PAD: 65,6 ± 8,90 mmHg), respectivamente. No entanto, nos estudantes obesos, a prevalência foi maior, abrangendo 26,3% (PAS: 113 ± 11,3 mmHg e PAD: 67,8 ± 10,1 mmHg) no gêneros masculino e 25% (PAS: 108 ± 14,4 mmHg e PAD: 68,3 ± 10,2 mmHg) no feminino. Conclusão: Os achados relatados neste estudo mostram altos índices de crianças e adolescentes acometidos tanto por excesso de peso quanto pela hipertensão arterial. Estes resultados sugerem a implementação de medidas preventivas e de tratamento dos fatores de risco cardiovascular em crianças e adolescentes do município de Vitória, ES.

Brain function predictors and outcome of weight loss and weight loss maintenance

Obesity rates are associated with public health consequences and rising health care costs. Weight loss interventions, while effective, do not work for everyone, and weight regain is a significant problem. Eating behavior is influenced by a convergence of processes in the brain, including homeostatic factors and motivational processing that are important contributors to overeating. Initial neuroimaging studies have identified brain regions that respond differently to visual food cues in obese and healthy weight individuals that are positively correlated with reports of hunger in obese participants. While these findings provide mechanisms of overeating, many important questions remain. It is not known whether brain activation patterns change after weight loss, or if they change differentially based on amount of weight lost. Also, little is understood regarding biological processes that contribute to long-term weight maintenance. This study will use neuroimaging in participants while viewing food and non-food images. Functional Magnetic Resonance Imaging will take place before and after completion of a twelve-week weight loss intervention. Obese participants will be followed though a 6-month maintenance period. The study will address three aims: 1. Characterize brain activation underlying food motivation and impulsive behaviors in obese individuals. 2. Identify brain activation changes and predictors of weight loss. 3. Identify brain activation predictors of weight loss maintenance. Findings from this study will have implications for understanding mechanisms of obesity, weight loss, and weight maintenance. Results will be significant to public health and could lead to a better understanding of how differences in brain activation relate to obesity.

Differences between the fourth and fifth Korotkoff phases among children and adolescents

BACKGROUND

The relative importance of the fourth (K4) and fifth (K5) Korotkoff phases as the indicator of diastolic blood pressure (DBP) levels among children remains uncertain.

METHODS

In a sample of 11,525 youth aged 5-17, we examined interexaminer differences in these 2 phases and the relation of theses 2 phases to adult blood pressure levels and hypertension. The longitudinal analyses were conducted among 2,156 children who were re-examined after age 25 years.

RESULTS

Mean (±SD) levels of DBP were 62 (±9) mm Hg (K4) and 49 (±13) mm Hg (K5). K4 showed less interobserver variability than did K5, and 7% of the children had at least 1 (of 6) K5 value of 0mm Hg. Longitudinal analyses indicated that K4 was more strongly associated with adult blood pressure levels and hypertension. In correlational analyses of subjects who were not using antihypertensive medications in adulthood (n = 1,848), K4 was more strongly associated with the adult DBP level than was K5 (r = 0.22 vs. 0.17; P < 0.01). Analyses of adult hypertension (based on high blood pressure levels or use of antihypertensive medications) indicated that the screening performance of childhood levels of K4 was similar to that of systolic blood pressure and was higher than that of K5, with areas under the receiver operator characteristic curves of 0.63 (systolic blood pressure), 0.63 (K4), and 0.57 (K5).

CONCLUSIONS

As compared with K5 levels among children, K4 shows less interobserver variability and is more strongly associated with adult hypertension.

Blood pressure tables for Chinese adolescents: justification for incorporation of important influencing factors of height, age and sex in the tables

Background

Elevated blood pressure (BP) in childhood was a predictor of hypertension in adulthood and contributes to the current epidemic of cardiovascular disease. It is necessary to identify abnormal BP in children and adolescents with accurate BP tables based on several crucial factors. The purpose of this study was to identify the important influencing factors of BP of Chinese adolescents.

Methods

BP, height, and body weight were assessed in 32221 normal-weight Chinese adolescents aged 12–17 years. An equal number of 6815 subjects from boys and girls were individually matched by height and age to assess the independent effect of sex on BP; and an equal number of 1422 subjects from each of the age groups (12, 13, 14, 15, 16 and 17 years) were individually matched by sex and height to estimate the independent effect of age on BP. Height of each sex and age was divided into eight height groups - ~5^th, ~10^th, ~25^th, ~50^th, ~75^th, ~90^th, ~95^th, and 95^th ~ percentiles- and the Spearman’s correlation between height percentiles and BP was used to examine the independent effect of height on BP.

Results

Boys had higher systolic BP (SBP) and diastolic BP (DBP) than girls after controlling for age and height. BP increased with age after controlling for sex and height. In each age group, both SBP and DBP increased alongside increasing height in boys and girls.

Conclusions

Sex, age and height are all independent determinants for BP levels in Chinese adolescents. It is essential to incorporate these three factors for the establishment of the BP reference tables.

Association between adiposity and blood pressure levels between the ages of 6 and 16 years. Analysis in a student population from Madrid, Spain

INTRODUCTION AND OBJECTIVES

The increase in the incidence of hypertension in children can be attributed to the rising prevalence of obesity. The objective is to analyze the impact of overweight and the degree or distribution of adiposity on blood pressure levels in a population of Spanish schoolchildren.

METHODS

A cross-sectional study was carried out in 1511 schoolchildren between 6 years and 16 years of age. We measured weight, height, waist circumference, subcutaneous skinfolds, and blood pressure. Nutritional categories were established on the basis of body mass index, waist-to-height ratio, and percent body fat. According to the National High Blood Pressure Education Program Working Group, subjects whose blood pressure was above the 90th percentile of the standard normal distribution were considered to have high blood pressure.

RESULTS

In all, 3.17% of the boys and 3.05% of the girls had high blood pressure. According to odds ratio analysis, the risk of high blood pressure increased in individuals with a body mass index indicative of obesity (7.87-fold in boys, 12.32-fold in girls), with a percent body fat>97th percentile (6.98-fold in boys, 18.51-fold in girls), or with a waist-to-height ratio ≥0.5 (10.56-fold in boys, 7.82-fold in girls).

CONCLUSIONS

Overweight and obesity increase the risk of high blood pressure in children between 6 years and 16 years of age, although the risk level varies depending on the amount and distribution of adipose tissue. Anthropometric indicators of relative adiposity and fat distribution are especially useful in the identification of children and adolescents with high blood pressure.

Secular trends in BMI and blood pressure among children and adolescents: the Bogalusa Heart Study

OBJECTIVE

The prevalence of obesity among children and adolescents increased by almost threefold from the 1970s to 2000. We examined whether these secular changes in BMI were accompanied by increases in blood pressure levels.

METHODS

A total of 24,092 examinations were conducted among 11,478 children and adolescents (aged 5-17 years) from 1974 to 1993 in the Bogalusa Heart Study (Louisiana).

RESULTS

The prevalence of obesity increased from 6% to 17% during this period. In contrast, only small changes were observed in levels of systolic blood pressure (SBP) and diastolic blood pressure (DBP), and neither mean nor high (based on the 90th percentile from the Fourth Report on the Diagnosis, Evaluation, and Treatment of High Blood Pressure in Children and Adolescents) levels increased over the 20-year period. Within each race-gender group, mean levels of SBP did not change, whereas mean levels of DBP decreased by 2 mm Hg (P < .001 for trend). Levels of BMI were positively associated with levels of SBP and DBP within each of the 7 examinations, and controlling for BMI (along with other covariates) indicated that only ~60% as many children as expected had high levels of blood pressure in 1993.

CONCLUSIONS

Our finding that levels of DBP and SBP among children in this large sample did not increase despite the increases that were seen in obesity indicates that changes in blood pressure levels in a population do not necessarily parallel changes in obesity. Additional study of the potential characteristics that have ameliorated the expected increase in high blood pressure could lead to further reductions in risk.

Cohort Profile: the international childhood cardiovascular cohort (i3C) consortium

This is a consortium of large children's cohorts that contain measurements of major cardiovascular disease (CVD) risk factors in childhood and had the ability to follow those cohorts into adulthood. The purpose of this consortium is to enable the pooling of data to increase power, most importantly for the follow-up of CVD events in adulthood. Within the consortium, we hope to be able to obtain data on the independent effects of childhood and early adult levels of CVD risk factors on subsequent CVD occurrence.

Global DNA methylation and risk of subclinical atherosclerosis in young adults: the Pathobiological Determinants of Atherosclerosis in Youth (PDAY) study

OBJECTIVE

The association between hepatic global DNA methylation measured using pyrosequencing technology and the risk of subclinical atherosclerosis was examined in the Pathobiological Determinants of Atherosclerosis in Youth (PDAY) study. PDAY is a bi-racial investigation of the natural history of atherosclerosis and its risk factors involving 3013 individuals aged 15-34 years who underwent autopsy after dying of unrelated causes in 1987-1994.

METHODS

Raised atherosclerotic lesions were defined as the sum of the percentages of intimal surface area detected in the right coronary artery and left half of the abdominal and thoracic aorta harboring fibrous plaques, complicated lesions, and calcified lesions during a postmortem pathological examination. To conduct the case-control study, 300 cases selected with the highest raised lesion scores were paired with 300 controls without raised lesions after matching for age, race, and gender.

RESULTS

Global DNA methylation was not associated with disease risk in the study population considered as a whole using conditional logistic regression models to analyze matched pairs. Since the estimation of the risk of atherosclerosis associated with inter-individual variation in DNA methylation was similar if unconditional logistic regression was used, subgroup analyses were carried out after adjusting for matching variables. A modest association with methylation levels below the median value was found in white but not in African-American study participants (odds ratio = 1.59, 95% confidence interval = 1.02-2.49, p = 0.04).

CONCLUSIONS

Hepatic global DNA methylation does not appear to be a definitive determinant of atherosclerosis burden in a postmortem sample of young adults.

Ethnic differences in hypertension incidence among middle-aged and older adults: the multi-ethnic study of atherosclerosis

The prevalence of hypertension is higher among blacks than whites. However, inconsistent findings have been reported on the incidence of hypertension among middle-aged and older blacks and whites, and limited data are available on the incidence of hypertension among Hispanics and Asians in the United States. Therefore, this study investigated the age-specific incidence of hypertension by ethnicity for 3146 participants from the Multi-Ethnic Study of Atherosclerosis. Participants, age 45 to 84 years at baseline, were followed for a median of 4.8 years for incident hypertension, defined as systolic blood pressure ≥140 mm Hg, diastolic blood pressure ≥90 mm Hg, or the initiation of antihypertensive medications. The crude incidence rate of hypertension, per 1000 person-years, was 56.8 for whites, 84.9 for blacks, 65.7 for Hispanics, and 52.2 for Chinese. After adjustment for age, sex, and study site, the incidence rate ratio (IRR) for hypertension was increased for blacks age 45 to 54 (IRR: 2.05 [95%CI: 1.47 to 2.85]), 55 to 64 (IRR: 1.63 [95% CI: 1.20 to 2.23]), and 65 to 74 years (IRR: 1.67 [95% CI: 1.21 to 2.30]) compared with whites but not for those 75 to 84 years of age (IRR: 0.97 [95% CI: 0.56 to 1.66]). Additional adjustment for health characteristics attenuated these associations. Hispanic participants also had a higher incidence of hypertension compared with whites; however, hypertension incidence did not differ for Chinese and white participants. In summary, hypertension incidence was higher for blacks compared with whites between 45 and 74 years of age but not after age 75 years. Public health prevention programs tailored to middle-aged and older adults are needed to eliminate ethnic disparities in incident hypertension.

Anthropometric Indices Associated with Variation in Cardiovascular Parameters among Primary School Pupils in Ile-Ife

Purpose. This study investigated the anthropometric indices associated with variations in cardiovascular parameters among primary school pupils in Ile-Ife. Method. One thousand and twenty-six pupils (age range 6-14 years, mean age 10.12 years) from ten schools were recruited with parents' informed consent. Anthropometric (Height (Ht), Weight (Wt), Abdominal Circumference (AC)) and cardiovascular (Systolic Blood Pressure (SBP), Diastolic Blood Pressure (DBP), Heart Rate (HR)) parameters were measured using standard instruments and procedures. Blood pressure (BP) was measured after ten minutes of quiet sitting. Body Mass Index (BMI), Rate Pressure Product (RPP) and Pulse Pressure (PP) were estimated. Results. Age, Ht, Wt, BMI, and AC correlated significantly (P < .01) with BP and PP. AC and BMI were predictors of BP, HR, RPP, and PP. Conclusion. Significant correlations exist between age, Ht, Wt, BMI, AC, and BP with weight being a more viable predictor of SBP and age a more viable predictor of DBP.

Determinants of blood pressure distribution in school children

BACKGROUND

Hypertension (potential risk for cardiovascular diseases) is a major health problem in developed and developing countries affecting approximately one billion individuals worldwide. Many of the risk factors associated with development of hypertension are preventable. Early identification of children at risk for hypertension is important to prevent serious complications. The present study aimed at determining the percentile of systolic blood and diastolic blood pressure and to investigate distribution of blood pressure and its association with anthropometric variables.

METHODS

A cross-sectional study among 701 school children (in the age group of 12-16 years), selected by stratified random sampling was conducted in Aligarh. Personal data were collected through a pre-tested questionnaire. Blood pressure, weight and height were measured through standardized techniques and quetelet index was used to determine BMI. The distributions of blood pressure by anthropometric characteristics were examined. Mean, standard deviation, chi square and correlation coefficient were used for statistical analysis using SPSS 12 software. High blood pressure was defined as systolic and/or diastolic blood pressure over the 95th percentile.

RESULTS

Out of 363 boys, 34 (9.36%) and out of 338 girls, 32 (9.46%) had hypertension with overall prevalence of 66 (9.4%) children. Mean systolic blood and diastolic blood pressure were higher as the range of weight, height and BMI increased and blood pressure of children showed positive correlation with anthropometrics characteristics.

CONCLUSIONS

It is therefore recommended that the children must be screened regularly for blood pressure to detect the prevalence so that remedial measure may be initiated as early as possible.

Influence of blood pressure on retinal vascular caliber in young children

OBJECTIVE

Prior studies have reported that blood pressure (BP) has a significant influence on retinal vascular caliber both in adults and children aged 6 years and older. This study aimed to examine the association between BP and retinal vascular caliber in Singapore Chinese preschoolers 4 to 5 years of age.

DESIGN

Population-based, cross-sectional study.

PARTICIPANTS

A total of 385 eligible and healthy Singapore Chinese children 4 to 5 years of age who were recruited in The Strabismus, Amblyopia and Refractive Error Study in Singaporean Chinese Preschoolers from May 2006 through October 2008 underwent BP measurements and retinal photography.

METHODS

According to standard protocols, BP was measured with an automatic Omron sphygmomanometer (Omron HEM 705 LP, Omron Healthcare, Inc., Bannockburn, IL) and a retinal photograph was obtained with a Canon 45° digital retinal camera (Model CR6-NM45, Canon, Inc., Tokyo, Japan) after pupil dilation. Anthropometric and optical biometric measurements such as height, weight, and axial length were obtained also. Information regarding sociodemographic status and child birth information was supplied by parents in either English or Chinese questionnaires.

MAIN OUTCOME MEASURES

The computer imaging program was used to measure the caliber of all retinal arterioles and venules located in zone B. The central retinal arteriolar equivalent and central retinal venular equivalent were estimated by using a revised Knudtson-Parr-Hubbard formula.

RESULTS

The mean retinal arteriolar and venular calibers were 156.19 μm and 220.01 μm in boys and 161.97 μm and 224.22 μm in girls. Higher systolic BP was associated with narrower retinal arterioles. After adjusting for age, gender, father's education, body mass index, birth weight, axial length, and caliber of the fellow retinal vessel, each 10-mmHg increase in systolic BP was associated with 2.00 μm (95% confidence interval, 0.39-3.61; P = 0.02) of retinal arteriolar narrowing and 2.51 μm (95% confidence interval, 0.35-4.68; P = 0.02) of retinal venular widening. However, neither diastolic BP nor mean arterial BP was associated with retinal arteriolar or venular caliber.

CONCLUSIONS

In very young children 4 to 5 years of age, higher systolic BP was associated with narrower retinal arterioles and wider retinal venules. This suggests that elevated BP may affect the retinal microvasculature from early childhood.

A survey of blood pressure in Lebanese children and adolescence

BACKGROUND

Blood pressure varies between populations due to ethnic and environmental factors. Therefore, normal blood pressure values should be determined for different populations.

AIMS

The aim of this survey was to produce blood pressure nomograms for Lebanese children in order to establish distribution curves of blood pressure by age and sex.

SUBJECTS AND METHODS

We conducted a survey of blood pressure in 5710 Lebanese schoolchildren aged 5 to 15 years (2918 boys and 2792 girls), and studied the distribution of systolic and diastolic blood pressure in these children and adolescents. Blood pressure was measured with a mercury sphygmomanometer using a standardized technique.

RESULTS

Both systolic and diastolic blood pressure had a positive correlation with weight, height, age, and body mass index (r= 0.648, 0.643, 0.582, and 0.44, respectively) (P < .001). There was no significant difference in the systolic and diastolic blood pressure in boys compared to girls of corresponding ages. However, the average annual increase in systolic blood pressure was 2.86 mm Hg in boys and 2.63 mm Hg in girls, whereas the annual increase in diastolic blood pressure was 1.72 mm Hg in boys and 1.48 mm Hg in girls. The prevalence of high and high-normal blood pressure at the upper limit of normal (between the 90(th) and 95(th) percentile, at risk of future hypertension if not managed adequately), was 10.5% in boys and 6.9% in girls, with similar distributions among the two sexes.

CONCLUSIONS

We present the first age-specific reference values for blood pressure of Lebanese children aged 5 to 15 years based on a good representative sample. The use of these reference values should help pediatricians identify children with normal, high-normal and high blood pressure.

Urinary angiotensinogen is correlated with blood pressure in men (Bogalusa Heart Study)

BACKGROUND

The Bogalusa Heart Study is a long-term study on cardiovascular disease and has followed a biracial (black/white) population from childhood. Risk factor data pertaining to many patients have been collected over 35 years, and the time course of hypertension has been documented by repeated examinations and measurements. Considerable sex and racial differences have been found to be related to cardiovascular disease. Urinary angiotensinogen (UAGT) is a novel biomarker for the intrarenal activity of the renin-angiotensin system in hypertension and kidney disease. We aimed to determine the relationship of UAGT with traditional cardiovascular disease risk factors in asymptomatic young adults in this biracial population.

METHOD

We recruited 251 individuals and collected a single random spot urine sample from each one. Because UAGT is significantly increased in diabetic patients and the use of antihypertensive drugs affects UAGT levels, we excluded patients who had diabetes, who were receiving antihypertensive treatment, or both. Consequently, 190 participants were included for this analysis.

RESULTS

UAGT levels did not differ with race or sex, but were significantly correlated with SBP (r = +0.23, P = 0.0015) and DBP (r = +0.24, P = 0.0012). Moreover, high correlations were shown in men, especially in black men (SBP, r = +0.85, P = 0.0005 and DBP, r = +0.72, P = 0.0079). Thus, UAGT is correlated with blood pressure in men, even when they do not show overt proteinuria or albuminuria.

CONCLUSION

The biomarker, UAGT, may facilitate the identification of individuals that are at increased risk for the development of hypertension and early asymptomatic renal disease.

Meta-analysis of blood pressure tracking from childhood to adulthood and implications for the design of intervention trials

AIM

Blood pressure (BP) is related with cardiovascular disease. BP tracking in childhood and its implication for intervention trials are unknown.

METHODS

A systematic review and meta-analysis were conducted to estimate BP tracking.

RESULTS

In 29 independent studies on 27,820 subjects, follow-up length and baseline age were associated with systolic BP tracking (both p < 0.05), while gender, BP measurement method and study place were not (p = 0.215, p = 0.185 and p = 0.391). The overall adjusted systolic BP correlation coefficient was 0.44 between 10 and 11 years and decreased to 0.37 between 10 and 20 years. Comparison of BP changes before and after intervention need a 26% increased sample size for a 10-year follow-up of 10 year olds, while trials comparing BP values at study end only require smaller sample sizes.

CONCLUSION

Blood pressure tracking from childhood to adulthood affects trials assessing long-term effects on BP and was low-to-moderate. Therefore, regular BP controls are also needed in children with normal BP measurements possibly identifying hypertensive children earlier. A slight short-term intervention effect on BP may not have any long-term effects because of low BP tracking and its decrease by age.

End-stage renal disease in young black males in a black-white population: longitudinal analysis of the Bogalusa Heart Study

Background

Risk factors in childhood create a life-long burden important in the development of cardiovascular (CV) disease in adulthood. Many risk factors for CV disease (e.g., hypertension) also increase the risk of renal disease. However, the importance of childhood risk factors on the development of chronic kidney disease and end-stage renal disease (ESRD) is not well characterized.

Methods

The current observations include data from Bogalusa Heart Study participants who were examined multiple times as children between 1973 and 1988.

Results

Through 2006, fifteen study participants subsequently developed ESRD in adulthood; seven with no known overt cause. Although the Bogalusa Heart Study population is 63% white and 37% black and 51% male and 49% female, all seven ESRD cases with no known overt cause were black males (p < 0.001). Mean age-adjusted systolic and diastolic blood pressure in childhood was higher among the ESRD cases (114.5 mmHg and 70.1 mmHg, respectively) compared to black (103.0 mmHg and 62.3 mmHg, respectively) and white (mean = 103.3 mmHg and 62.3 mmHg, respectively) boys who didn't develop ESRD. The mean age-adjusted body mass index in childhood was 23.5 kg/m² among ESRD cases and 18.6 kg/m² and 18.9 kg/m² among black and white boys who didn't develop ESRD, respectively. Plasma glucose in childhood was not significantly associated with ESRD.

Conclusion

These data suggest black males have an increased risk of ESRD in young adulthood. Elevated body mass index and blood pressure in childhood may increase the risk for developing ESRD as young adults.

Synchronization of adolescent blood pressure and pubertal somatic growth

BACKGROUND

Blood pressure (BP) and growth increase at an accelerated rate during puberty. The temporal relationship of the two events has not been well characterized.

OBJECTIVE

The purpose of this current investigation was to examine the rate of BP change in relation to pubertal growth with the intent to shed light on new mechanisms by which BP is regulated.

METHODS

We examined data from a cohort of 182 normotensive children who had measurements made semiannually for up to 12 yr. From the recorded heights, we identified the subject-specific pubertal growth spurt (PGS) using a growth curve model. With the estimated PGS as an anchoring point, we obtained the rates at which BP and weight changed as continuous functions of time for the duration of pubertal growth. Examining BP on a scale relative to PGS placed BP development in the context of pubertal growth.

RESULTS

Average ages at PGS were 11.5 for girls and 13.3 for boys. Fitted spline models estimated that at the time of PGS, the mean systolic BP was 100 mm Hg for girls and 107 mm Hg for boys; the mean diastolic BP at the PGS was 59 mm Hg for girls and 61 mm Hg for boys. The most intriguing observation was that rate of change in systolic BP and weight peaked at precisely the estimated PGS.

CONCLUSION

The time synchronization of rates of change in BP, weight, and height suggests common regulating mechanisms for somatic growth and BP or growth changes that secondarily affect BP.

Blood pressure differences by ethnic group among United States children and adolescents

Large differences in blood pressure (BP) by ethnic group are apparent among adults. There is uncertainty as to whether similar differences by ethnic group exist among children and, if so, the age of onset. BP measurements were obtained from 58 698 children at 78 556 visits using Pediatric Task Force data, a collection of 11 studies with BP data from children and adolescents age 1 to 17 years. Generalized estimating equation methods were used to identify sex-specific differences in body mass index (BMI)-adjusted rates of BP elevation and prehypertension by ethnic group. Significant BMI-adjusted differences in rates of BP elevation were found between Hispanic boys versus white boys (odds ratio: 1.21; 95% CI: 1.07 to 1.37; P=0.002). No overall significant differences were found between black boys versus white boys (odds ratio: 1.03; 95% CI: 0.95 to 1.12; P=0.49); however, there was significant effect modification (P=0.01) with significant differences found for normal-weight boys (BMI: <85th percentile; OR black versus white: 1.14; 95% CI: 1.03 to 1.27; P=0.01) but not for overweight boys (BMI: > or =85th percentile; OR black versus white: 0.90; 95% CI: 0.78 to 1.05; P=0.20). No overall ethnic group differences in BMI-adjusted rates of hypertension were found for girls. Ethnic differences in prevalence rates of pediatric BP elevation that are not explained by obesity are present, primarily in boys. Whether these differences are attributable to genetic or environmental factors is unknown.

Blood pressure and body mass index in an ethnically diverse sample of adolescents in Paramaribo, Suriname

BACKGROUND

High blood pressure (BP) is now an important public health problem in non-industrialised countries. The limited evidence suggests ethnic inequalities in BP in adults in some non-industrialised countries. However, it is unclear whether these ethnic inequalities in BP patterns in adults reflect on adolescents. Hence, we assessed ethnic differences in BP, and the association of BP with body mass index (BMI) among adolescents aged 12-17 years in Paramaribo, Suriname.

METHODS

Cross-sectional study with anthropometric and blood pressure measurements. A random sample of 855 adolescents (167 Hindustanis, 169 Creoles, 128 Javanese, 91 Maroons and 300 mixed-ethnicities) were studied. Ethnicity was based on self-reported ethnic origin.

RESULTS

Among boys, Maroons had a lower age- and height-adjusted systolic BP than Creoles, and a lower diastolic BP than other ethnic groups. However, after further adjustment for BMI, only diastolic BP in Maroons was significantly lower than in Javanese (67.1 versus 70.9 mmHg). Creole boys had a lower diastolic BP than Hindustani (67.3 versus 70.2 mmHg) and Javanese boys after adjustment for age, height and BMI. Among girls, there were no significant differences in systolic BP between the ethnic groups. Maroon girls, however, had a lower diastolic BP (65.6 mmHg) than Hindustani (69.1 mmHg), Javanese (71.2 mmHg) and Mixed-ethnic (68.3 mmHg) girls, but only after differences in BMI had been adjusted for. Javanese had a higher diastolic BP than Creoles (71.2 versus 66.8 mmHg) and Mixed-ethnicity girls. BMI was positively associated with BP in all the ethnic groups, except for diastolic BP in Maroon girls.

CONCLUSION

The study findings indicate higher mean BP levels among Javanese and Hindustani adolescents compared with their African descent peers. These findings contrast the relatively low BP reported in Javanese and Hindustani adult populations in Suriname and underscore the need for public health measures early in life to prevent high BP and its sequelae in later life.

Effects of dairy intake on weight maintenance

BACKGROUND

To compare the effects of low versus recommended levels of dairy intake on weight maintenance and body composition subsequent to weight loss.

DESIGN AND METHODS

Two site (University of Kansas-KU; University of Tennessee-UT), 9 month, randomized trial. Weight loss was baseline to 3 months, weight maintenance was 4 to 9 months. Participants were maintained randomly assigned to low dairy (< 1 dairy serving/d) or recommended dairy (> 3 servings/d) diets for the maintenance phase. Three hundred thirty eight men and women, age: 40.3 +/- 7.0 years and BMI: 34.5 +/- 3.1, were randomized; Change in weight and body composition (total fat, trunk fat) from 4 to 9 months were the primary outcomes. Blood chemistry, blood pressure, resting metabolism, and respiratory quotient were secondary outcomes. Energy intake, calcium intake, dairy intake, and physical activity were measured as process evaluation.

RESULTS

During weight maintenance, there were no overall significant differences for weight or body composition between the low and recommended dairy groups. A significant site interaction occurred with the low dairy group at KU maintaining weight and body composition and the low dairy group at UT increasing weight and body fat. The recommended dairy group exhibited reductions in plasma 1,25-(OH)2-D while no change was observed in the low dairy group. No other differences were found for blood chemistry, blood pressure or physical activity between low and recommended dairy groups. The recommended dairy group showed significantly greater energy intake and lower respiratory quotient compared to the low dairy group.

CONCLUSION

Weight maintenance was similar for low and recommended dairy groups. The recommended dairy group exhibited evidence of greater fat oxidation and was able to consume greater energy without greater weight gain compared to the low dairy group. Recommended levels of dairy products may be used during weight maintenance without contributing to weight gain compared to diets low in dairy products.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00686426.

Blood pressure variability and classification of prehypertension and hypertension in adolescence

OBJECTIVE

There is little information in pediatrics on the persistence of the prehypertension and hypertension classifications or on the progression of prehypertension to hypertension. This study aimed to examine those issues.

METHODS

An analysis of data from the National Childhood Blood Pressure database was conducted to examine the longitudinal blood pressure outcomes for adolescents classified after a single measurement of blood pressure. Adolescent subjects (N = 8535) for whom serial single blood pressure measurements were obtained at intervals of 2 years were identified. Subjects were stratified according to blood pressure status at the initial measurement, as having normotension, prehypertension, or hypertension.

RESULTS

Among subjects designated as having prehypertension (n = 1470), 14% of boys and 12% of girls had hypertension 2 years later. Among subjects designated as having hypertension, 31% of boys and 26% of girls continued to exhibit hypertension, and 47% of boys and 26% of girls had blood pressure values in the prehypertensive range. Regression models showed no significant effect of race on blood pressure changes but significant effects of initial BMI and changes in BMI.

CONCLUSIONS

These data indicated that the rate of progression of prehypertension to hypertension was approximately 7% per year. Prehypertension can be predictive of future hypertension and may benefit from preventive interventions, especially lifestyle changes.

Determination of blood pressure percentiles in normal-weight children: some methodological issues

Blood pressure in children has consistently been related to adult blood pressure, with implications for long-term prevention of cardiovascular disease. The epidemic of obesity in children has resulted in corresponding increases in childhood blood pressure. In this paper, the authors develop norms for childhood blood pressure among normal-weight children (body mass index <85th percentile based on Centers for Disease Control and Prevention guidelines) as a function of age, sex, and height, using data from 49,967 children included in the database of the National High Blood Pressure Education Program Working Group on High Blood Pressure in Children and Adolescents (the Pediatric Task Force). The authors considered three types of models for pediatric blood pressure data, including polynomial regression, restricted cubic splines, and quantile regression, with the latter providing the best fit. The sex-specific norms presented here are a nonlinear function of both age and height and are generally slightly lower than previously developed norms based on Pediatric Task Force data including both normal-weight and overweight children.

Systolic blood pressure in childhood predicts hypertension and metabolic syndrome later in life

OBJECTIVE

The goal was to link hypertension and the metabolic syndrome in adulthood directly to blood pressures measured decades earlier for the same individuals as children and to establish criterion values for blood pressure that predict hypertension and the metabolic syndrome later in life.

METHODS

We analyzed serial data for 240 men and 253 women in the Fels Longitudinal Study. We derived age- and gender-specific childhood blood pressures that predict hypertension and the metabolic syndrome in adulthood, and we validated these criterion values in a larger sample.

RESULTS

Blood pressure diverged between adults with and without the metabolic syndrome beginning at age 5 for boys and age 8 for girls. The odds ratios for developing hypertension at > or = 30 years of age ranged from 1.1 for 14- to 18-year-old boys to 3.8 for 5- to 7-year-old boys and from 2.7 for 8- to 13-year-old girls to 4.5 for 5- to 7-year-old girls, if their blood pressure exceeded criterion values at a single examination in childhood. The corresponding odds ratios for the metabolic syndrome, with or without hypertension, ranged from 1.2 for 14- to 18-year-old boys to 2.6 for 8- to 13-year-old boys and from 1.5 for 14- to 18-year-old girls to 3.1 for 5- to 7-year-old girls. The relative risk of adult hypertension ranged from 1.5 to 3.8 for boys and from 1.5 to 4.7 for girls, and that of the metabolic syndrome ranged from 1.1 to 1.8 for boys and from 1.2 to 5.6 for girls. These relative risks varied directly with the number of examinations at which systolic blood pressure exceeded criterion values.

CONCLUSION

Children with systolic blood pressures above the criterion values established in this longitudinal study are at increased risk of hypertension and the metabolic syndrome later in life.

High blood pressure in school children: prevalence and risk factors

Background

The purpose of this study was to determine the prevalence of high blood pressure (HBP) and associated risk factors in school children 8 to 13 years of age.

Methods

Elementary school children (n = 1,066) were examined. Associations between HBP, body mass index (BMI), gender, ethnicity, and acanthosis nigricans (AN) were investigated using a school based cross-sectional study. Blood pressure was measured and the 95^th percentile was used to determine HBP. Comparisons between children with and without HBP were utilized. The crude and multiple logistic regression adjusted odds ratios were used as measures of association.

Results

Females, Hispanics, overweight children, and children with AN had an increased likelihood of HBP. Overweight children (BMI ≥ 85^th percentile) and those with AN were at least twice as likely to present with HBP after controlling for confounding factors.

Conclusion

Twenty one percent of school children had HBP, especially the prevalence was higher among the overweight and Hispanic group. The association identified here can be used as independent markers for increased likelihood of HBP in children.

Hypertension in children and adolescents

Hypertension is one of the most common health problems in the United States and a powerful independent risk factor for cardiovascular and renal disease. Until recently, the incidence of persistent hypertension in children has been low, with a range of 1% to 3%. Recent data indicate that over the last decade, however, average blood pressure levels have risen substantially among American children. Obesity and other lifestyle factors, such as physical inactivity and increased intake of high-calorie, high-salt foods, are thought to be responsible for this trend. Hypertension in children is currently recognized as an important health issue. There is increasing evidence that hypertension has its antecedents during childhood, because adult blood pressure often correlates with childhood blood pressure. Hypertension in children also is viewed as a significant risk factor for the development of cardiovascular disease in adulthood.