Tracking of blood pressure in Australian children

Preterm Birth, Kidney Function and Cardiovascular Disease in Children and Adolescents

Over recent decades, there has been a global increase in preterm birth rate, which constitutes about 11% of total births worldwide. The present review aims to summarize the current knowledge on the long-term consequences of prematurity on renal and cardiovascular development and function. Recent literature supports that prematurity, intrauterine growth restriction or low birth weight (LBW) may have an adverse impact on the development of multiple organ systems, predisposing to chronic diseases in childhood and adulthood, such as arterial hypertension and chronic kidney disease. According to human autopsy and epidemiological studies, children born preterm have a lower nephron number, decreased kidney size and, in some cases, affected renal function. The origin of hypertension in children and adults born preterm seems to be multifactorial as a result of alterations in renal, cardiac and vascular development and function. The majority of the studies report increased systolic and diastolic blood pressure (BP) in individuals born preterm compared to full term. The early prevention and detection of chronic non-communicable diseases, which start from childhood and track until adulthood in children with a history of prematurity or LBW, are important.

The mediating pathways between parental separation in childhood and offspring hypertension at midlife

Social life course determinants of adult hypertension are relatively unknown. This paper examines how parental separation before age 10 relates to hypertension at age 46. Adjusting for parental confounders and considering the role of adult mediators, we aim to quantify unexplored mediating pathways in childhood using prospectively collected data. Data from the 1970 British Birth Cohort Study are utilised. Hypertension is measured by health care professionals at age 46. Potential mediating pathways in childhood include body mass index (BMI), systolic and diastolic blood pressure, illness, disability, family socioeconomic status (SES) and cognitive and developmental indicators at age 10. Additionally, we explore to what extent childhood mediators operate through adult mediators, including health behaviours, family SES, BMI and mental wellbeing. We also test for effect modification of the relationship between parental separation and hypertension by gender. Nested logistic regression models test the significance of potential mediating variables. Formal mediation analysis utilising Karlson Holm and Breen (KHB) method quantify the direct and indirect effect of parental separation on offspring hypertension at midlife. There was an association between parental separation and hypertension in mid-life in women but not men. For women, family SES and cognitive and behavioural development indicators at age 10 partly mediate the relationship between parental separation and hypertension at age 46. When adult mediators including, health behaviours, family SES, BMI and mental wellbeing are included, the associations between the childhood predictors and adult hypertension are attenuated, suggesting that these childhood mediators in turn may work through adult mediators to affect the risk of hypertension in midlife. We found family SES in childhood, cognitive and behaviour development indicators at age 10, including disruptive behaviour, coordination and locus of control in childhood, to be important mediators of the relationship between parental separation and midlife hypertension suggesting that intervening in childhood may modify adult hypertension risk.

The Get-Up! study: adiposity and blood pressure in Australian toddlers

BACKGROUND

Because the elevated blood pressure (BP) in childhood is strongly associated with overweight and is a risk factor for later cardiovascular disease, a need to comprehend the early development of BP and its association with overweight is needed. We assessed differences of BP by weight status in Australian toddlers.

METHODS

From the Get-Up! Study in Australia, this sample included 265 toddlers (136 boys), aged 19.6 ± 4.2 months. BP was measured with a digital vital signs monitor. Participants were categorized as nonoverweight and overweight according to the World Health Organization definition for body mass index (BMI). Physical activity was captured with activPAL accelerometers, during childcare hours. To test differences in BP between nonoverweight and overweight children, we performed an analysis of covariance adjusting for sex, age, physical activity, and socioeconomic status.

RESULTS

Children with overweight showed higher z systolic BP values (P = .042 for BMI and P = .023 for waist circumference) when compared to nonoverweight children. However, no differences were found for z diastolic BP levels, between overweight and nonoverweight children. After adjustments for potential confounders (socioeconomic status, physical activity, sex, and age), there were no significant differences in BP variables between BMI and waist circumference groups.

CONCLUSIONS

No associations between adiposity and BP levels were found in this sample. The unadjusted results, however, showed that children with higher levels of adiposity (BMI and waist circumference) exhibited higher levels of BP. Additional research is needed to determine which environmental and genetic factors might contribute to pediatric hypertension, particularly among toddlers.

Longitudinal blood pressure patterns and cardiovascular disease risk

Observational and interventional studies have unequivocally demonstrated that "present", i.e. single-occasion, blood pressure is one of the key determinants of cardiovascular disease risk. Over the past two decades, however, numerous publications have suggested that longitudinal blood pressure data and assessment of long-term blood pressure exposure provide incremental prognostic value over present blood pressure. These studies have used several different indices to quantify the overall exposure to blood pressure, such as time-averaged blood pressure, cumulative blood pressure, blood pressure trajectory patterns, and age of hypertension onset. This review summarises existing research on the association between these indices and hard cardiovascular outcomes, outlines the strengths and weaknesses of these indices, and provides an overview of how longitudinal blood pressure changes can be measured and used to improve cardiovascular disease risk prediction.KEY MESSAGESNumerous recent publications have examined the relation between cardiovascular disease and long-term blood pressure (BP) exposure, quantified using indices such as time-averaged BP, cumulative BP, BP trajectory patterns, and age of hypertension onset.This review summarises existing research on the association between these indices and hard cardiovascular outcomes, outlines the strengths and weaknesses of these indices, and provides an overview of how longitudinal BP changes can be measured and used to improve cardiovascular disease risk prediction.Although longitudinal BP indices seem to predict cardiovascular outcomes better than present BP, there are considerable differences in the clinical feasibility of these indices along with a limited number of prospective data.

Comparison of echocardiographic changes in children with primary hypertension and hypertension due to mild to moderate chronic kidney disease

BACKGROUND

Chronic systemic hypertension has a well-known association with increased cardiovascular morbidity and mortality. One of the most important target organs affected in systemic hypertension is the heart. In addition, chronic kidney disease (CKD) further increases the mortality from cardiovascular disease. The aim of this study was to evaluate the differences in the cardiovascular changes in pediatric patients with primary hypertension (pHTN) vs. those with secondary hypertension from chronic kidney disease (CKD-HTN).

METHODS

This was a retrospective chart review of patients with CKD-HTN and pHTN. The medical records were reviewed for anthropometric data, biochemical assessment of renal function, and for cardiovascular changes on echocardiogram.

RESULTS

Twenty-three patients with pHTN and 29 patients with CKD-HTN were included in the study. There were no differences in age, gender, weight, height, body mass index, and blood pressure between the 2 groups. There was a high prevalence of left ventricular diastolic dysfunction among both the groups (CKD-HTN 25 vs. pHTN 26%). Reduced mitral valve inflow Doppler E/A ratio, a marker of left ventricular diastolic dysfunction in echocardiogram, was more pronounced in CKD-HTN patents, in comparison to those with pHTN (p = 0.042). Also, diastolic function worsened with declining glomerular filtration rate in patients with CKD-HTN. Similarly, patients with CKD-HTN had a larger aortic root dimension when compared to patients with pHTN (p = 0.049).

CONCLUSIONS

The prevalence of left ventricular diastolic dysfunction is similar in patients with pHTN and CKD-HTN. Patients with CKD-HTN appear to have more severe diastolic dysfunction and larger aortic root dimensions.

Relationships between depression and anxiety symptoms scores and blood pressure in young adults

BACKGROUND

Depression and anxiety are risk factors for cardiovascular disease, but their relationship to blood pressure (BP) is less clear. Age-related comorbidity and lifestyle factors may confound these relationships. This study aimed to assess the relationships among BP, depression and anxiety symptom scores and self-reported history of depression in young adults.

METHOD

Data on 1014 participants aged 20 years from the Western Australian Cohort (Raine) Study were analyzed for cross-sectional associations between clinic BP and Depression, Anxiety, Stress Scale questionnaire scores or a reported history of depression, accounting for relevant confounders.

RESULTS

Multivariable adjusted analyses showed an inverse relationship between SBP with depression (coefficient = -0.10; P = 0.012) and anxiety (after excluding two outliers with SBP > 156 mmHg, coefficient = -0.13; P = 0.018) scores, independent of sex, BMI, female hormonal contraceptive use, alcohol consumption, birth weight and maternal hypertension in pregnancy. SBP was 1.6 mmHg lower for 2 SD (16 units) increase in depression score. There was an inverse association between self-reported history of depression (15.8% of participants) and SBP (coefficient = -1.91; P = 0.023), with an interaction with increasing BMI (interaction coefficient = -0.43; P = 0.002) enhancing this difference.

CONCLUSION

Our findings show that SBP in young adults is inversely associated with depression and anxiety scores, independent of a range of lifestyle confounders. Despite a positive association between BMI and BP, adiposity enhanced the inverse association between self-reported history of depression and SBP. These findings contrast with the predisposition of depressed participants to cardiovascular disease in later life when decades of unhealthy lifestyle changes may dominate.

Association Between Serum Levels of Uric Acid and Blood Pressure Tracking in Childhood

BACKGROUND

Recent studies suggest that high levels of serum uric acid of very early life are a result of the in-utero environment and may lead to elevated blood pressure (BP) in adulthood. However, serum uric acid levels can change throughout life. We investigated the effect of serum uric acid levels in childhood on the BP tracking and analysed BP according to changes in serum uric acid levels in early life.

METHODS

A total of 449 children from the Ewha Birth and Growth Cohort study underwent at least 2 follow-up examinations. Data were collected across 3 check-up cycles. Serum uric acid levels, BP, and anthropometric characteristics were assessed at 3, 5, and 7 years of age.

RESULTS

Children with a serum uric acid level higher than the median values had significantly increased systolic BP (SBP) and diastolic BP at 3 years of age. Baseline serum uric acid levels measured at 3 years of age, significantly affected subsequent BP in the sex and body mass index adjusted longitudinal data analysis (P < 0.05). Considering the changing pattern of serum uric acid over time, subjects with high uric acid levels at both 3 and 5 years of age had the highest SBP at 7 years of age.

CONCLUSIONS

These findings suggest the importance of maintaining an adequate level of serum uric acids from the early life. Appropriate monitoring and intervention of uric acid levels in a high-risk group can reduce the risk of a future increased BP.

Childhood to Early-Midlife Systolic Blood Pressure Trajectories: Early-Life Predictors, Effect Modifiers, and Adult Cardiovascular Outcomes

Previous studies examining blood pressure change over time have modeled an average population trajectory. Recent research among older adults suggests there may be subgroups with different blood pressure trajectories. Identifying subgroups at risk of developing adult hypertension early in life can inform effective risk reduction efforts. We sought to identify different systolic blood pressure trajectories from childhood, their correlated risk factors, and early-midlife cardiovascular outcomes. Blood pressure data at ages 7, 11, 18, 26, 32, and 38 years from a longitudinal, representative birth cohort study (n=975) were used to identify 4 distinct trajectory groups via group-based trajectory modeling: normal (21.8%), high-normal (43.3%), prehypertensive (31.6%), and hypertensive (4.2%). The categories refer to blood pressure beginning at the age of 7 years and most recently measured at the age of 38 years. Family history of high blood pressure (odds ratio [OR], 43.23; 95% confidence interval [CI], 5.27-354.65), male sex (OR, 109.48; 95% CI, 26.82-446.96), being first born (OR, 2.5; 95% CI, 1.00-8.69) and low birth weight (OR, 2.79; 95% CI, 2.49-3.09) were associated with hypertensive group membership (compared with the normal group). Higher body mass index and cigarette smoking resulted in increasing blood pressure across trajectories, particularly for the higher blood pressure groups. Prehypertensive and hypertensive trajectory groups had worse cardiovascular outcomes by early midlife. Harmful blood pressure trajectories are identifiable in childhood, associated with both antecedent and modifiable risk factors over time, and predict adult cardiovascular disease risk. Early detection and subsequent targeted prevention and intervention may reduce the lifecourse burden associated with higher blood pressure.

Epidemiology of elevated blood pressure in youth and its utility for predicting adulthood outcomes: A review

Elevated blood pressure has been demonstrated to track from youth to adulthood and some have demonstrated an association between early-life blood pressure and subsequent atherosclerosis and cardiovascular disease. In addition, reports regarding the strength of tracking are inconsistent and the modifiable risk factors that affect the trajectory of blood pressure from youth to adulthood remain unclear. This paper comprehensively evaluated the existing classifications of youth hypertension and the current trends of youth hypertension. Further, evidence for the consequences of hypertension in youth has been comprehensively evaluated. Importantly, a review of the studies examining tracking from youth to adulthood has been performed and a number of studies investigating the factors affecting tracking has also been investigated. The overall consideration of this body of literature highlights the vital importance of identifying hypertension in youth to prevent complications in adulthood. Adiposity is regarded to be a factor affecting the progression of hypertension from youth to adulthood yet there is little evidence available for other modifiable factors. It is apparent that further research is necessary within this field in order to create effective preventative strategies to target youth hypertension.

A 24-year follow-up study of blood pressure tracking from childhood to adulthood in Korea: the Kangwha Study

PURPOSE

A number of longitudinal studies have tracked blood pressure over time in children and adults. Although there are a few blood pressure tracking studies for Asian populations, they are all relatively short-term studies with around only 10 years of follow-up. Accordingly, we assessed the stability of blood pressure tracking from childhood to adulthood over a 24-year follow-up period among participants in the Kangwha Study.

MATERIALS AND METHODS

The Kangwha Study was a community- based prospective cohort study that started in 1986 in Kangwha County, South Korea. The study dataset included 14 blood pressure measurements over a 24-year period from 266 (123 male and 143 female) participants who completed the 2010 examination. All participants were 7 years old when the study began and were followed for the next 24 years.

RESULTS

The tracking coefficient (95% confidence interval) for systolic blood pressure was 0.81 (0.52-1.11) in men and 0.72 (0.51-0.92) in women; diastolic blood pressure was 0.53 (0.26-0.80) in men and 0.33 (0.15-0.52) in women. After adjusting for body mass index, the tracking coefficient for systolic blood pressure was 0.68 (0.39-0.97) in men and 0.67 (0.44-0.89) in women; diastolic blood pressure was 0.51 (0.24-0.78) in men and 0.33 (0.15-0.51) in women. All tracking coefficients were statistically significant (p<0.001).

CONCLUSION

In this 24-year longitudinal study, we confirmed the stability of blood pressure tracking from childhood to adulthood for participants in the Kangwha Study.

Severe obesity in children and adolescents: identification, associated health risks, and treatment approaches: a scientific statement from the American Heart Association

Severe obesity afflicts between 4% and 6% of all youth in the United States, and the prevalence is increasing. Despite the serious immediate and long-term cardiovascular, metabolic, and other health consequences of severe pediatric obesity, current treatments are limited in effectiveness and lack widespread availability. Lifestyle modification/behavior-based treatment interventions in youth with severe obesity have demonstrated modest improvement in body mass index status, but participants have generally remained severely obese and often regained weight after the conclusion of the treatment programs. The role of medical management is minimal, because only 1 medication is currently approved for the treatment of obesity in adolescents. Bariatric surgery has generally been effective in reducing body mass index and improving cardiovascular and metabolic risk factors; however, reports of long-term outcomes are few, many youth with severe obesity do not qualify for surgery, and access is limited by lack of insurance coverage. To begin to address these challenges, the purposes of this scientific statement are to (1) provide justification for and recommend a standardized definition of severe obesity in children and adolescents; (2) raise awareness of this serious and growing problem by summarizing the current literature in this area in terms of the epidemiology and trends, associated health risks (immediate and long-term), and challenges and shortcomings of currently available treatment options; and (3) highlight areas in need of future research. Innovative behavior-based treatment, minimally invasive procedures, and medications currently under development all need to be evaluated for their efficacy and safety in this group of patients with high medical and psychosocial risks.

Managing cardiovascular risk in overweight children and adolescents

The scientific, medical, and lay communities are currently confronted with a serious medical and public health problem related to the marked non-remitting worldwide epidemic of obesity. This ever-increasing prevalence of obesity is accompanied by a host of inherently associated co-morbidities. As a result, obesity is fast becoming the major cause of premature death in the developed world. As pediatric and adult cardiologists, we have seen a dramatic increase in office referrals of overweight and obese children and adolescents, who already have obesity-related degenerative disease processes such as hypertension, dyslipidemia, the metabolic syndrome, and type 2 diabetes mellitus, as well as manifestations of early preclinical atherosclerotic cardiovascular disease, not previously observed in this age group. This article presents a review of the literature and recent scientific statements and recommendations issued by the American Heart Association (AHA) and the American Academy of Pediatrics (AAP) regarding the metabolic abnormalities associated with obesity, including newer identification and treatment strategies for obesity, dyslipidemia, and early subclinical coronary artery disease seen in high-risk children and adolescents.

Relationship between height and blood pressure in Japanese schoolchildren

BACKGROUND

Blood pressure examinations for health education use have been conducted at several schools in Japan. It has been reported that blood pressure is closely associated with bodyweight and height in US children. The aim of the present paper was to evaluate the association between height and blood pressure in Japanese schoolchildren.

METHODS

In Iwata city in Japan, blood pressure screening was conducted by the school administration. A total of 98.9% (10,152/10,270 children) of all fifth (10-year-olds) and ninth graders (14-year-olds) residing in the Old Iwata area from 2002 to 2007 were analyzed.

RESULTS

In 10-year-old and 14-year-old boys, regression analysis indicated that a positive correlation between weight and blood pressure was the strongest among the three body size indices (height, weight, and body mass index), but the association between height and blood pressure was also significant. For girls from both the 10 and 14 year age groups, the correlation of weight and blood pressure was stronger than those for the other body size indices, but there were also significant associations between height and blood pressure, except for height and diastolic blood pressure in the 14-year-olds.

CONCLUSIONS

There is a significant positive relationship between height and blood pressure. Further study is necessary to provide a blood pressure reference based on height in the Japanese program to prevent children from developing lifestyle-related risk factors.

A 15-year longitudinal study on ambulatory blood pressure tracking from childhood to early adulthood

This study evaluates the tracking stability of office blood pressure (BP), ambulatory BP (ABP), BP variability (BPV) and nocturnal BP drops (dipping) from childhood to early adulthood, and their dependence on ethnicity, gender and family history (FH) of essential hypertension (EH). Generalized estimating equations (GEEs) were used to estimate tracking coefficients for 295 European Americans and 252 African Americans, with a maximum of 12 measurements over a 15-year period. Office BP and ABP had moderate-to-relatively high tracking coefficients (r= 0.30-0.59; P<or=0.001). Twenty-four hour readings tracked better than office readings for diastolic BP (DBP; 0.57 vs. 0.46, P=1.72 x 10(-6)) and pulse pressure (PP) (0.59 vs. 0.51, P=2.70 x 10(-4)), and equally well for systolic BP (SBP; 0.55 vs. 0.54, P=0.805). Daytime readings tracked better than their night-time counterparts for SBP (0.50 vs. 0.37, P=7.62 x 10(-13)), DBP (0.49 vs. 0.30, P=7.98 x 10(-32)) and PP (0.55 vs. 0.50, P=0.0061). All BPV (r=0.08-0.28; P<or=0.001) and dipping measures (r=0.07-0.12; odds ratio, 1.60-1.73; P<or=0.001) had low tracking coefficients. Males had significantly higher tracking stability for office SBP, DBP and ambulatory PP than females (P<0.01). Subjects with a positive FH of EH had significantly higher tracking stability for daytime and night-time DBP and dipping indexed by continuous variables than those with a negative FH (P<0.001). No significant ethnic differences were observed. The high tracking stability of 24-h ABP highlights the importance of using ambulatory BP monitoring in both research and clinical settings.

Tracking of blood pressure from childhood to adulthood: a systematic review and meta-regression analysis

BACKGROUND

A large number of studies have examined the tracking of blood pressure (BP) from childhood to adulthood, but the reported findings are inconsistent and few systematic analyses have been conducted.

METHODS AND RESULTS

We conducted a systematic search of PubMed for studies that examined the tracking of BP from childhood to adulthood published between January 1970 and July 2006. From 301 retrieved papers, 50 cohort studies met our inclusion criteria and provided 617 data points (Pearson/Spearman correlation coefficients) for systolic BP (SBP) and 547 data points for diastolic BP (DBP) for our meta-analysis. Information on sample characteristics and BP measurement protocols was extracted. Fisher z transformation and random-effects meta-regression analysis were conducted. The reported BP tracking correlation coefficients varied from -0.12 to 0.80 for SBP and from -0.16 to 0.70 for DBP, with an average of 0.38 for SBP and 0.28 for DBP. BP tracking varied significantly by baseline age and length of follow-up. The strength of BP tracking increased with baseline age by 0.012 for SBP (P<0.001) and 0.009 for DBP (P<0.001) and decreased with follow-up length by 0.008 for SBP (P<0.001) and 0.005 for DBP (P<0.001). BP tracking did not vary markedly across the number of BP measurements or race/population groups.

CONCLUSIONS

Data from diverse populations show that the evidence for BP tracking from childhood into adulthood is strong. Childhood BP is associated with BP in later life, and early intervention is important.

Pediatric hypertension: recent trends and accomplishments, future challenges

Publication of the Fourth Report on high blood pressure (BP) in children and adolescents by the National High BP Education Program (NHBPEP) in 2004 has been followed by a remarkable increase in interest in pediatric hypertension. New data have emerged on the epidemiology of hypertension in the young, the influence of the childhood obesity epidemic on BP, how ambulatory BP monitoring (ABPM) can be used in evaluating elevated BP and the extent of hypertensive target-organ damage in the pediatric age group. Exciting new information on drug treatment of pediatric hypertension has been produced by industry-sponsored clinical trials of antihypertensive medications spurred by the FDA Modernization Act (FDAMA) and successor legislation. Despite these trends, recognition of elevated BP in children and adolescents by primary care providers remains problematic. This article will highlight these and other aspects of pediatric hypertension, hopefully providing a snapshot of where we are in early 2008, and pointing out areas where further work is needed in order to reduce the future burden of adult cardiovascular disease.

Childhood obesity, hypertension, the metabolic syndrome and adult cardiovascular disease

1. The worldwide epidemic of obesity in adults has been mirrored in children in developed and developing countries. 2. Central obesity appears to be driving a cluster of abnormalities often referred to as the metabolic syndrome. 3. The definition of the metabolic syndrome in children is not suited to arbitrary cut-offs and a definition using the significant clustering of risk factors that is already evident in childhood and adolescent populations may be preferable. 4. An Australian population study showed that 25% of 8-year-olds and 29% of 14-year-olds could be described by the high risk cluster with features similar to adult metabolic syndrome. 5. The high risk cluster was significantly linked to high and low birthweight, shorter duration of breast-feeding, larger postnatal weight gains after 12 months of age and raised C-reactive protein, gamma glutamyl transferase and alanine transaminase levels. At-risk young adults have also been shown to have macroscopic atherosclerosis in post-mortem studies. 6. Identification of at-risk children has obvious benefits for the individual and as well, for prevention of a future cohort with raised cardiovascular morbidity and mortality; however, complexities and controversies exist in doing so. Familial, genetic and lifestyle risk factors aggregate and labelling children with predisease may be problematic. Committed political and societal changes are necessary to reduce childhood obesity and subsequent adult cardiovascular disease.

Inter-relationships between body mass index, C-reactive protein and blood pressure in a Hispanic pediatric population

BACKGROUND

The link between inflammation, obesity, and cardiovascular disease (CVD) has been described in adult populations but few data are available with respect to children. The aim of this study was to describe the inter-relationships between adiposity, C-reactive protein (CRP) plasma concentrations, and blood pressure levels in a Hispanic pediatric population.

METHODS

We included 325 schoolchildren (mean age, 10.0 years) selected from the school population of Bucaramanga, Colombia. Blood pressure, lipid profile, glucose, and CRP plasma concentration were measured using standard procedures. Body mass index (BMI) was used for evaluating the children's nutritional condition. Correlation coefficients were calculated for all the variables using Spearman's test.

RESULTS

As expected, a positive correlation was found between BMI and systolic blood pressure (SBP) in both genders, and between CRP and SBP levels in boys. After a multivariate regression analysis, the association between adiposity and blood pressure remained significant, whereas the CRP concentrations were no longer associated with SBP.

CONCLUSIONS

The results obtained in our study of Hispanic school-age children show that adiposity is correlated with CRP concentrations and SBP values as has been earlier described in Caucasian populations. However, we failed to find a significant relationship between low-grade inflammation and SBP levels. Further studies are needed in order to explore alternative pathophysiological mechanisms linking obesity and high blood pressure in children and to define the impact of these associations on the cardiovascular risk of our pediatric population.

Impacts of Measurement Protocols on Blood Pressure Tracking From Childhood Into Adulthood

The best approach for blood pressure (BP) measurement in children remains controversial, specifically regarding the choice of Korotkoff phase 4 versus Korotkoff phase 5 for diastolic BP (DBP) and the use of automated devices. To examine the impacts of different BP measurement protocols on BP tracking from childhood into adulthood, we conducted a meta-analysis of 50 related studies published between 1970 and 2006 identified based on a systematic search of PubMed. These studies provided 617 data points (tracking correlation coefficient, our outcome variable) for systolic BP and 547 data points for DBP for our meta-analysis. The explanatory variables included the use of Korotkoff phase 4/Korotkoff phase 5, BP device, and number of BP measurements per visit. Analyses were adjusted for potential confounders, including sex, baseline age, follow-up length, publication year, and study country. Tracking correlation coefficients for DBP measured using Korotkoff phase 4 was higher than that of Korotkoff phase 5 by 0.035 but not significant. DBP tracking assessed by automated device was higher than that of Korotkoff phase 5 by 0.152 ( P =0.024) and higher than the mercury manometer by 0.223 ( P =0.005). BP tracking was slightly higher with multiple BP measurements per visit, but measurements of ≥3 times did not improve the tracking further compared with 2 measurements. Although policy-making bodies currently recommend the use of Korotkoff phase 5 to assess DBP in children, our metaregression analysis did not support the recommendation. In general, Korotkoff phase 4 seems to be different from Korotkoff phase 5, and automated device is a promising approach for BP assessment in childhood.

Overweight and blood pressure: results from the examination of a selected group of adolescents in northern Italy

OBJECTIVE

The aim of the present study was to investigate blood pressure (BP) levels and their relationship with different indices of body fat in a group of adolescents, in order to evaluate the prevalence of hypertension and plan preventive and corrective strategies.

DESIGN

Cross-sectional study in primary care.

SETTING

All high schools in the Aosta Valley region, northern Italy.

SUBJECTS

Five hundred and thirty-two adolescents of both sexes, aged 15.4 (standard deviation 0.7) years. The following parameters were measured: body weight, body height, body mass index (BMI), four skinfold thicknesses, body fat mass, waist and hip circumferences and BP.

RESULTS

BMI data indicated a high prevalence of overweight subjects in both sexes, but higher in males, while the prevalence rate of obese adolescents was lower. Of the total, 11.8 % of subjects suffered from systolic hypertension, while 6.9 % suffered from diastolic hypertension. In linear correlation analysis, BMI and all adiposity indices, except waist:hip ratio, were found to be significantly associated (P ranging between 0.05 and 0.001) with both systolic BP and diastolic BP in both sexes, with r ranging between 0.152 and 0.359. Multiple regression analysis with the stepwise method showed BMI and body fat mass to have the strongest association (P < 0.001) with BP, with r ranging between 0.275 and 0.359.

CONCLUSION

Unless reversed, these conditions are worrying and predict the possible development of cardiovascular disease in adulthood. There is a pressing need to develop a comprehensive medical and nutrition plan, together with preventive and corrective strategies, in school programmes.

Health and nutrition education program in primary schools of Crete: changes in blood pressure over 10 years

OBJECTIVE

To examine the long-term effects of the 'Cretan Health and Nutrition Education Program' on blood pressure.

SUBJECTS

A representative population of 176 pupils (85 from the intervention schools and 91 from the control schools).

DESIGN

Blood pressure, dietary, anthropometrical and physical activity data were obtained at baseline (academic year 1992-1993) and at follow-up examination (academic year 2001-2002).

RESULTS

The findings of the current study revealed that the increase over the 10-year period in systolic (SBP) and diastolic blood pressure (DBP) was higher in the control group (CG) than in the intervention group (IG) (P=0.003 and P<0.001 respectively). Regarding dietary indices, the IG were found to have a significantly higher intake of potassium (P=0.018) and magnesium (P=0.011) compared to the CG. Furthermore, the decrease in body mass index (BMI) z-score observed in the IG was found to differentiate significantly from the increase observed in the CG (P=0.042). On the contrary, the increase in leisure time, moderate to vigorous physical activities (MVPA) observed in the IG, was found to differentiate significantly from the decrease observed in the CG (P=0.032). Intervention's effect on SBP was mediated by changes in MVPA (beta=-0.20, P=0.030) and BMI (beta=0.19, P=0.048). Similarly, intervention's effect on DBP was mediated by changes in MVPA (beta=-0.18, P=0.048), BMI (beta=0.26, P=0.007) and magnesium intake (beta=-0.20, P=0.048).

CONCLUSION

The findings of the current study are encouraging, indicating favorable changes in blood pressure, micronutrients intake, BMI and physical activity over the 10 years of follow-up and 4 years after program's cessation, thus providing some support for the effectiveness of school-based health education programs in successfully tackling certain chronic disease risk factors early in life.

Nutrition education in postmenopausal women: Changes in dietary and cardiovascular indices

OBJECTIVE

The aim of the current study was to examine whether a diet rich in dairy products followed by a nutrition education program for the prevention of osteoporosis could have any adverse effect on certain cardiovascular disease (CVD) risk factors over a 5-month intervention period.

METHODS

A total sample of 82 women (55-65 years old) was randomized to a dietary intervention group (IG: n=42), attending biweekly nutrition education program and provided with low-fat, fortified dairy products and to a control group (CG: n=40). Changes in dietary, biochemical and clinical indices related to CVD were determined at the end of the 5-month intervention period.

RESULTS

The IG was found to have a higher decrease in the percentage of energy intake derived from total fat and a higher increase in the intake of calcium, phosphorus, magnesium and potassium compared to the CG (p<0.05). Furthermore, the IG subjects were found to have a lower increase in BMI (0.7+/-0.1 versus 1.4+/-0.2 Kg/m(2), p=0.011) and systolic blood pressure (SBP) (2.5+/-2.9 versus 7.8+/-2.2 mmHg, p=0.040) and a higher decrease in serum total cholesterol (-5.2+/-3.3 versus 6.9+/-5.1 mg/dl, p=0.042) and LDL-cholesterol levels (-20.0+/-2.6 versus -12.4+/-4.2 mg/dl, p=0.034) compared to the CG.

CONCLUSIONS

The findings of the current study indicate that a dietary intervention aiming to minimize the risk for osteoporosis did not have any adverse effects on CVD risk factors. On the contrary, it has induced favourable changes in BMI, serum lipids and SBP.

Follow-up on metabolic markers in children treated for obstructive sleep apnea

RATIONALE

In adults, obstructive sleep apnea (OSA) is associated with metabolic dysfunction that improves with treatment of OSA. No equivalent studies exist in children.

OBJECTIVE

To examine the relationship between metabolic markers and OSA with time and treatment in children.

METHODS

Metabolic markers measured on a fasting morning blood sample at diagnostic polysomnography and follow-up 1.3 +/- 0.6 yr later.

MEASUREMENTS AND MAIN RESULTS

Forty-five children (34 males), aged 6.9 +/- 3.5 yr, and including 12 obese subjects, were in the final analysis. There were no differences in metabolic markers between children with and without OSA at initial study; however, obese children had significantly higher insulin (106.1 +/- 72.1 vs. 66.7 +/- 37.6 pmol/L; p = 0.028), insulin/glucose ratio (23.7 +/- 14.3 vs. 14.7 +/- 8.0; p = 0.02), and significantly lower high-density lipoprotein cholesterol (1.3 +/- 0.2 vs. 1.6 +/- 0.4 nmol/L; p = 0.005) than nonobese children. Twenty children underwent surgical removal of adenotonsillar tissue, whereas 12 children with OSA elected not to have treatment. OSA persisted after treatment in five children, and resolved in 27. Thirteen children did not have OSA on initial or follow-up studies. At follow-up, there was a small but significant improvement in total cholesterol in those children whose OSA was resolved (4.8 +/- 0.8 to 4.7 +/- 0.6 nmol/L; p = 0.005) and a trend for obese children with persisting OSA to have elevated insulin levels compared with obese children without OSA (p = 0.07).

CONCLUSION

Obesity appears to be the major influence on metabolic dysfunction in children with OSA, but these preliminary data also suggest that resolution or persistence of OSA may affect changes in metabolic function over time.

Treatment of primary and secondary hypertension in children

The incidence of pediatric hypertension (HTN) is increasing, mainly due to an increase in primary (essential) HTN, or PH. There are only a limited number of studies assessing the characteristics and treatment efficacy of PH versus secondary HTN (SH). We conducted a retrospective analysis of 158 pediatric patients (mean age: 10.8 years; sex ratio: 51.1% female, 48.9% male) with HTN of whom 34.4% had PH and 65.6% had SH. The vast majority were either African-American or Caucasian. Among all patients, therapy induced a significant decrease in systolic blood pressure (SBP) and diastolic BP (DBP) (both p<0.0001). SBP (p<0.0001) and DBP (p=0.002) declined significantly in PH patients. PH and SH patients with a body mass index (BMI) >95th percentile (%) had a significantly higher post-therapy SBP (both p<0.05) than those with a BMI <95th%. SBP declined similarly in PH patients treated with calcium-channel blockers (CCB) and angiotensin-converting enzyme inhibitors (ACEI). DBP declined only in PH patients treated with ACEI. SBP and DBP (both p<0.0001) declined significantly in SH patients. Post-therapy BP was similar in SH patients treated with either CCB or ACEI. Post-therapy SBP and DBP were significantly lower in SH patients than in PH patients; moreover, therapy induced a greater decline in SBP and DBP in the SH patients. Compared to PH patients, SH patients were twofold more likely to achieve a SBP less than the 95th% after therapy. We conclude that (1) significant lowering of BP with either CCB or ACEI is achievable in most children with HTN, and (2) SH patients respond better to therapy than those with PH.

Diet and blood pressure in children

PURPOSE OF REVIEW

The prevalence of hypertension among children in the US is increasing in concert with rising obesity rates. Leading health organizations agree that elevated blood pressure should be managed in children; however, data on the relation between diet and lifestyle and blood pressure in this age group are sparse and controversial. The purpose of this review is to summarize the current evidence regarding nutrients, foods, and dietary patterns and their role in blood pressure elevation and in the treatment of pediatric hypertension.

RECENT FINDINGS

There is clear evidence that avoidance of excess weight gain in early life is important for the prevention of future hypertension and that weight reduction is an important therapeutic intervention for the prevention and treatment of hypertension in overweight children. Similarly, reduction in dietary sodium may be beneficial for children who are salt sensitive, but this trait cannot be easily measured. Children who were breast-fed or consume a diet rich in fruits, vegetables, and dairy foods tend to have lower blood pressure in adolescence. How these foods lower blood pressure is unclear.

SUMMARY

Data supporting the efficacy of dietary interventions for preventing or treating high blood pressure are limited. Future studies should emphasize adequate sample size, adjustment for confounding factors, use of standardized blood pressure techniques, and random assignment of children in intervention trials. Additionally, because adherence to dietary interventions may be particularly problematic among children, innovative nutrition intervention approaches are needed that address the unique needs and circumstances of this age group.

Hypertension research in the 21st century

This paper presents a signpost for hypertension research, emphasizing areas most likely to yield major clinical and public health benefits. Specific questions are posed in the context of fetal and maternal precursors of cardiovascular disease, vascular biology, resistant hypertension, antihypertensive drugs, primary aldosteronism, lifestyle and genetic interactions and translational research. Worldwide increasing rates of obesity and diabetes demonstrate the need for a global approach to cardiovascular risk and the need for more effective use of existing knowledge. Equal emphasis is given to the critical importance of the fundamental research required to defeat hypertensive cardiovascular disease in the long run.

Obesity and blood pressure--results from the examination of 2365 schoolchildren in Germany

OBJECTIVES

To investigate the relationship between different indices of body fat and blood pressure in children and adolescents.

DESIGN

Cross-sectional cohort study along with regular public health service examinations in school classes two, five and nine.

PARTICIPANTS

A total of 2365 healthy schoolchildren aged 8-16 y.

MEASUREMENTS

Body mass index (BMI), skinfolds, waist-hip ratio, body fat determined by bioelectric impedance analysis and blood pressure.

RESULTS

In comparison with recently published normative data, a significant increase of obesity was found. There is a higher prevalence of obesity in children with lower education. A positive association between body fat and hypertension was observed in children aged above 10 y. The BMI had the strongest association with blood pressure among the indices of body fat considered here.

CONCLUSION

Obesity is an increasing problem even among schoolchildren. This observation should be treated seriously as the relationship of body fat to cardiovascular risk is detectable already at a young age. Attention should be paid to the dependence of obesity on the level of education. The analysis suggests that BMI should be the preferred index to assess body fat. International Journal of Obesity (2003) 27, 1459-1464. doi:10.1038/sj.ijo.0802462

Renin-angiotensin-aldosterone system loci and multilocus interactions in young-onset essential hypertension

OBJECTIVE

Renin-angiotensin-aldosterone system component genes have been associated to essential hypertension. Thus, we studied the association of singe locus or multilocus interactions with young-onset essential hypertension.

SETTING AND DESIGN

This is a case-control study based on a population sample of adolescent at an inner city.

PARTICIPANTS

We studied 54 adolescents with hypertension and 121 age-matched normotensives, recruited from a high-school student population of 934 interviewed individuals.

METHODS

Resting blood pressure was measured on three different days and normalized (Z-score) by sex and age. Genotypes of ACE (I/D) angiotensinogen (T174M and M235T), ATIR (A1166C), and CYP11B2 (C-344T) were determined by PCR/RFLP or ASO.

RESULTS

Although genotype frequencies were not different in both groups, we found a significant dominant effect of ACE D and angiotensinogen 235T alleles on normalized systolic arterial blood pressure in males. This effect was confirmed by sib-pair linkage analysis taking normalized blood pressure as a quantitative trait. We independently analyzed multilocus interactions in normotensive and hypertensive adolescents searching for multiple locus deviation from Hardy-Weinberg or linkage equilibrium. We found that from 63 multilocus combinations, 4 deviated significantly from equilibrium in hypertensive adolescents but none in the normotensives. Deviations from equilibrium may indicate that the combination of alleles at different loci affects susceptibility or resistance to the disease.

CONCLUSION

In addition to the angiotensin-converting enzyme (ACE) and angiotensinogen (AGT) gene variants, gene-gene interactions may be important causative factors in a complex disease such as young-onset essential hypertension.