Central blood pressure and pulse wave amplification across the spectrum of peripheral blood pressure in overweight and obese youth

Prevalence of hypertension and its associations with body composition across Chinese and American children and adolescents

BACKGROUND

The age of onset of hypertension (HTN) is decreasing, and obesity is a significant risk factor. The prevalence and racial disparities in pediatric HTN and the association between body composition and blood pressure are insufficiently studied. This study aimed to evaluate the prevalence of HTN in Chinese and American children and adolescents and to assess the relationship between various body composition indices and HTN.

METHODS

Seven thousand, five hundred and seventy-three Chinese and 6239 American children and adolescents aged 8-18 years from the 2013-2015 China Child and Adolescent Cardiovascular Health study and the 2011-2018 National Health and Nutrition Examination Surveys were analyzed. Blood pressure and body composition (fat and muscle) were measured by trained staff. The crude prevalence and age-standardized prevalence rate (ASPR) of primary HTN and its subtypes [isolated systolic hypertension (ISH) and isolated diastolic hypertension (IDH)] were calculated based on 2017 American Academy of Pediatrics guidelines. Multivariable-adjusted linear regression coefficients and odds ratios (ORs) were calculated to assess the associations of body composition indicators with HTN, ISH and IDH.

RESULTS

The ASPR of HTN was 18.5% in China (CN) and 4.6% in the United States (US), whereas the obesity prevalence was 7.4% and 18.6%, and the population attributable risk of HTN caused by overweight and obesity was higher in the US than in CN. Increased fat mass, muscle mass and body fat percentage mass were associated with a higher risk of HTN in both countries. The percent of muscle body mass had a protective effect on HTN and ISH in both countries [HTN (CN: OR = 0.83, 95% CI = 0.78-0.88; US: OR = 0.72, 95% CI = 0.64-0.81); ISH (CN: OR = 0.87, 95% CI = 0.80-0.94; US: OR = 0.71, 95% CI = 0.62-0.81)], and the protective effect was more common among children and adolescents with high levels of physical activity.

CONCLUSIONS

The burden of HTN in Chinese children and adolescents was substantial and much greater than that in the US, and the contribution of obesity to HTN was higher in the US than in CN. Augmenting the proportion of muscle mass in body composition has a protective effect against HTN in both populations. Optimizing body composition positively influences blood pressure in children and adolescents, particularly those with high-level physical activity. Video abstract (MP4 149982 KB).

The significance of central blood pressure for cardiovascular target organ damage in children and adolescents after kidney transplantation

BACKGROUND

Cardiovascular (CV) complications are important causes of morbidity and mortality in children after kidney transplantation (KTx). In adults, central blood pressure (cBP) is an accepted predictor of CV sequelae. We aimed to assess the prognostic value of cBP over peripheral blood pressure (pBP) for existing CV damage.

METHODS

We measured cBP and pBP in 48 pediatric KTx recipients (mean age: 13.5 ± 4.2 years). Assessment of left ventricular mass index (LVMI) and aortic pulse wave velocity (PWV) allowed detection of CV target organ damage. LVMI and PWV were used as endpoints in multivariable linear regression models, in which cBP and pBP were compared for their predictive value.

RESULTS

Using cBP z-scores, we identified a larger number of patients with uncontrolled or untreated hypertension compared to pBP (36% vs. 7%). Central systolic blood pressure (cSBP) was a significant independent predictor of LVMI, while peripheral systolic blood pressure (pSBP) was not. Comparing central (cDBP) and peripheral (pDBP) diastolic blood pressure for their predictive value on PWV revealed a greater estimate for cDBP (0.035 vs. 0.026 for pDBP) along with a slightly better model fit for cDBP.

CONCLUSIONS

Our data in a small group of patients provide first evidence that cBP measurements in pediatric KTx recipients might be helpful in identifying patients at risk for the development of CV sequelae. Investigating a larger patient number, ideally repeatedly, is needed to create further evidence supporting our findings. In light of available devices measuring cBP noninvasively, the implementation of such clinical studies post-KTx care should be feasible. A higher resolution version of the Graphical abstract is available as Supplementary information.

Isolated systolic hypertension in the young: a heterogeneous condition

Isolated systolic hypertension in the youth, is still a challenging problem. The prevalence of this hypertensive subtype may vary according to the different population study and is peculiar of male subjects among the youngest age classes. Several are the mechanisms reported as possible underlying causes of isolated systolic blood pressure elevation and again these differ according to the different study cohort and may vary from overweight and obesity status, linked to sympathetic overactivity, to increased and earlier arterial stiffness, hyperkinetic state, or exaggerated pulse pressure amplification form central to peripheral sites, due to enhanced arterial elasticity. Evidence is lacking regarding whether this condition is benign or associated to unfavorable cardiovascular events. The few long-term studies that followed isolated systolic hypertensives in the long-term, again reported conflicting results. Waiting for future studies, some clinical and hemodynamic characteristics of young isolated systolic hypertensives may help clinicians to better characterized patient's risk profile and decide whether to perform a strict follow-up with non-pharmacological measurements or to start drug treatment.

Relationship between heart rate and central aortic blood pressure: implications for assessment and treatment of isolated systolic hypertension in the young

Isolated systolic hypertension in the young (ISHY) remains a challenging problem, partly due to the differences in central aortic pressure observed in studies investigating ISHY. The fundamental relationship between heart rate and central aortic pressure, and more precisely, the relationship between heart rate and amplification of central aortic pressure in the periphery, underpins the assessment and, as a consequence, the treatment of ISHY. Physiology warrants that an increase in heart rate would lead to increased amplification of the pressure pulse between the aorta and the brachial artery. Heart rate generally decreases with age, in particular over the first two decades of life. Thus, a higher heart rate in the young would result in higher pulse pressure amplification, and therefore an elevated brachial systolic pressure would not necessarily translate to elevated aortic systolic pressure. However, elevated heart rate is not a consistent feature in ISHY, and studies have shown that ISHY can present with either high or low central aortic systolic pressure. In this brief review, we summarize the physiological aspects underlying the relationship between heart rate and central aortic blood pressure and its amplification in the brachial artery, how this relationship changes with age, and examine the implications of these effects on the assessment and treatment of ISHY.

Demographics of childhood hypertension in the UK: a report from the Southeast England

We aimed to describe hypertensive phenotype and demographic characteristics in children and adolescents referred to our paediatric hypertension service. We compared age, ethnicity and BMI in primary hypertension (PH) compared to those with secondary hypertension (SH) and white coat hypertension (WCH). Demographic and anthropometric data were collected for children and adolescents up to age 18 referred to our service for evaluation of suspected hypertension over a 6 year period. Office blood pressure (BP) and out of office BP were performed. Patients were categorised as normotensive (normal office and out of office BP), WCH (abnormal office BP, normal out of office BP), PH (both office and out of office BP abnormal, no underlying cause identified) and SH (both office and out of office BP abnormal, with a secondary cause identified). 548 children and adolescents with mean ± SD age of 10.1 ± 5.8 years and 58.2% girls. Fifty seven percent (n = 314) were hypertensive; of these, 47 (15%), 84 (27%) and 183 (58%) had WCH, PH and SH, respectively. SH presented throughout childhood, whereas PH and WCH peaked in adolescence. Non-White ethnicity was more prevalent within those diagnosed with PH than both the background population and those diagnosed with SH. Higher BMI z-scores were observed in those with PH compared to SH. Hypertensive children <6 years are most likely to have SH and have negligible rates of WCH and PH. PH accounted for 27% of hypertension diagnoses in children and adolescents, with the highest prevalence in adolescence, those of non-White Ethnicity and with excess weight.

Hypertension in obese children is associated with vitamin D deficiency and serotonin dysregulation

Background

Obesity and hypertension represent serious health issues affecting the pediatric population with increasing prevalence. Hypovitaminosis D has been suggested to be associated with arterial hypertension. Serotonin by modulating nitric oxide synthase affect blood pressure regulation. The biological mechanism by which vitamin D specifically regulates serotonin synthesis was recently described. The aim of this paper is to determine the associations between vitamin D, serotonin, and blood pressure in obese children.

Methods

One hundred and seventy-one children were enrolled in the prospective cross-sectional study. Two groups of children divided according to body mass index status to obese (BMI ≥95th percentile; n = 120) and non-obese (n = 51) were set. All children underwent office and ambulatory blood pressure monitoring and biochemical analysis of vitamin D and serotonin. Data on fasting glucose, insulin, HOMA, uric acid, and complete lipid profile were obtained in obese children.

Results

Hypertension was found only in the group of obese children. Compared to the control group, obese children had lower vitamin D and serotonin, especially in winter. The vitamin D seasonality and BMI-SDS were shown as the most significant predictors of systolic blood pressure changes, while diastolic blood pressure was predicted mostly by insulin and serotonin. The presence of hypertension and high-normal blood pressure in obese children was most significantly affected by vitamin D deficiency and increased BMI-SDS.

Conclusions

Dysregulation of vitamin D and serotonin can pose a risk of the onset and development of hypertension in obese children; therefore, their optimization together with reducing body weight may improve the long-term cardiovascular health of these children.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-022-03337-8.

Association of blood pressure, obesity and physical activity with arterial stiffness in children: a systematic review and meta-analysis

Central pulse wave velocity (cPWV) is a biomarker for cardiovascular (CV) risk and a predictor for CV events in adulthood. Alterations of arterial stiffness have also been associated with CV risk in childhood. The study aimed to systematically review and meta-analyze the association of blood pressure (BP), body mass index (BMI), and cardiorespiratory fitness (CRF) with cPWV in children. Literature search was through the databases PubMed, Web of Science, Embase and the Cochrane Register of Controlled Trials. Twenty-two articles were included in the systematic review and eight articles in the meta-analysis. Higher systolic and diastolic BP were associated with higher cPWV (pooled estimated effect size (ES) 0.02 (95% CI: 0.012-0.027; P < 0.001), and ES 0.02 (95% CI: 0.011-0.029; P < 0.001); respectively). Higher BMI correlated with higher cPWV (ES 0.025 (95% CI: 0.013-0.038; P < 0.001)). CRF was inversely associated with cPWV (ES -0.033 (95% CI: -0.055 to -0.011; P = 0.002)). In children, higher BP and BMI are already related to increased cPWV, and enhanced CRF may be a preventive strategy to counteract development of CV disease later in life. IMPACT: This meta-analysis suggests that elevated blood pressure and body mass index in childhood correlate with increased central pulse wave velocity. Children with higher cardiorespiratory fitness appear to have favorably lower arterial stiffening. Elevated blood pressure and altered arterial stiffness originate early in life and childhood risk stratification as well as timely initiation of exercise treatment may help counteract development of manifest cardiovascular disease later in life.

Cardiovascular mortality risk in young adults with isolated systolic hypertension: findings from population-based MONICA/KORA cohort study

The clinical significance of isolated systolic hypertension in young adults (ISHY) remains a topic of debate due to evidence ISHY could be a spurious condition resulting from exageratted pulse pressure amplification in "young tall men with elastic arteries". Hence, we aimed to investigate whether ISHY is associated with an increased risk of cardivascular (CVD) mortality in a sample of 5597 young adults (49.8% men, 50.2% women) between 25 and 45 years old from the prospective population-based MONICA/KORA cohort. ISHY was prevalent in 5.2% of the population, affecting mostly men (73.1%), and associated with increased smoking, obesity, and hypercholesterolemia in comparison to participants with normal blood pressure (BP). Within a follow-up period of 25.3 years (SD ± 5.2; 141,768 person-years), 133(2.4%) CVD mortality cases were observed. Participants with ISHY had a hazard ratio (HR) of 1.89(1.01-3.53, p < 0.05) times higher risk of CVD mortality than participants with normal BP, even following adjustment for CVD risk factors. However, adjustment for antihypertensive medication (HR 0.46; 0.26-0.81, p < 0.001) and increasing height (HR 0.96; 0.93-0.99, p < 0.05) revealed independently protective effects against CVD mortality, suggesting that although ISHY is associated with an increased risk of CVD mortality, the protective effects of increasing height or antihypertensive medication should be considered in treatment rationale.

Racial differences of early vascular aging in children and adolescents

The prevalence of non-communicable disease (NCDs) is rising globally, with a large burden recorded in sub-Saharan countries and populations of black race/ethnicity. Accelerated vascular deterioration, otherwise known as early vascular aging (EVA), is the underlying factor for highly prevalent NCDs such as hypertension. The etiology of EVA is multifactorial with a central component being arterial stiffness with subsequent development of hypertension and cardiovascular complications. Although arterial stiffness develops with increasing age, many children and adolescents are subjected to the premature development of arterial stiffness, due to genetic or epigenetic predispositions, lifestyle and behavioral risk factors, and early life programming. Race/ethnic differences in pediatric populations have also been reported with higher aortic stiffness in black (African American) compared with age-matched white (European American) counterparts independent of blood pressure, body mass index, or socioeconomic status. With known evidence of race/ethnic differences in EVA, the pathophysiological mechanisms underlying graded differences in the programming of EVA are still sparse and rarely explored. This educational review aims to address the early life determinants of EVA in children and adolescents with a particular focus on racial or ethnic differences.

Relationship between office isolated systolic or diastolic hypertension and white-coat hypertension across the age spectrum: a home blood pressure study

OBJECTIVE

The current study investigated the prevalence of white-coat hypertension (WCH) and white-coat uncontrolled hypertension (WUCH) throughout the age spectrum among individuals with office isolated systolic hypertension (ISH), isolated diastolic hypertension (IDH) and systolic-diastolic hypertension (SDH) who were untreated or treated with antihypertensive medications, respectively.

METHODS

We cross-sectionally evaluated 8809 untreated (42% males, 52.1 ± 16.2 years) and 9136 treated (39% males, 59.7 ± 14.5 years) individuals from two independent Brazilian populations who underwent home blood pressure monitoring. Participants were also categorized as younger (<40 years), intermediate (≥40 and <60 years) and older (≥60 years) age.

RESULTS

Unadjusted and adjusted analyses showed that the frequency of WCH and WUCH was significantly greater (P < 0.05) in ISH and IDH than SDH at all age groups. Logistic regression analysis adjusted for sex, BMI and studied population showed that, compared with SDH, ISH had in average 4.1, 3.1 and 1.6-fold greater risk of WCH and 3.3, 3.6 and 2.0-fold greater risk of WUCH at younger, intermediate and older ages, whereas IDH had in average 2.3, 2.6 and 2.0-fold greater risk of WCH and 3.8, 3.2 and 3.8-fold greater risk of WUCH at younger, intermediate and older ages, respectively.

CONCLUSION

ISH and IDH were associated with higher prevalence of WCH and WUCH than SDH across all age spectrum. In addition, treated and untreated ISH individuals with age less than 60 years and treated IDH individuals of all ages had the highest risk of having WCH phenotypes.

Cardiovascular risk assessment in children and adolescents with congenital solitary kidneys

Patients with solitary kidneys (SKs) are at risk of hypertension (HT) and associated end-organ damage. The authors aimed to evaluate whether children with congenital SKs (CSKs) have higher office, ambulatory, or central blood pressure (BP), increased arterial stiffness or left ventricular mass index, or any risk for arrhythmia. With this purpose, patients with CSK and healthy controls being followed up between January 2018 and June 2019 were enrolled in the study. Demographic, biochemical, and office blood pressure (BP) data were recorded. Then, ambulatory blood pressure monitoring (ABPM) and measurements of central BP (cBP), pulse wave velocity (PWV), and augmentation index (AIx@75) were obtained. Ventricular repolarization parameters were acquired by 12-lead electrocardiography. Left ventricular mass index (LVMI) and abdominal aortic stiffness parameters including strain, pressure strain elastic modulus (Ep), and normalized Ep (Ep*) were calculated with echocardiographic measurements. Finally, 36 children with CSK and 36 healthy controls were included. Serum creatinine, uric acid, total cholesterol levels, ABPM parameters, cBP levels, and PWV values were significantly higher, and eGFR levels were significantly lower in the CSK group. VR parameters, abdominal aortic stiffness indices, and LVMI were similar between the groups. CSK increased the risk of HT in ABPM (HT_ABPM ) by 6 times. PWV was significantly correlated with Ep and Ep* in cases with CSK. Determination of cBP and PWV along with 24-hour ABPM would be a useful tool in children with CSK.

Ambulatory hemodynamic patterns, obesity, and pulse wave velocity in children and adolescents

BACKGROUND

In recent years, pulse wave velocity (PWV) has emerged as a surrogate marker of cardiovascular disease in children with cardiovascular risk factors. The aims of the present study were to identify determinants of PWV in children according to their weight status and to investigate the role of peripheral blood pressure and central hemodynamic parameters in the association between PWV and obesity.

METHODS

We included in the study healthy children and adolescents randomly selected from a school-based blood pressure screening study. All participants underwent ambulatory blood pressure monitoring and 24-h pulse wave analysis.

RESULTS

Overweight and obese children had higher 24-h PWV, 24-h peripheral and central systolic blood pressure (SBP), and cardiac output than normal weight ones. Children with both overweight and hypertension presented the highest 24-h PWV values (p < 0.001). Peripheral and central SBP, body mass index (BMI), and hemodynamic parameters, including stroke volume, cardiac output, total peripheral resistance, and cardiac index, were all associated with 24-h PWV. However, in stepwise regression analysis, 24-h peripheral and central SBP and cardiac index, but not BMI, were independent predictors of 24-h PWV. There were statistically significant differences in 24-h blood pressure and hemodynamic parameters among those on the lower and highest 24-h PWV quartile, but there were no significant differences in BMI among 24-h PWV quartile groups.

CONCLUSIONS

Arterial stiffness is higher in overweight and obese children in the co-presence of hypertension. Peripheral and central SBP are the main determinants of 24-h PWV independent of weight status. Graphical abstract.

Blood Pressure and Body Weight Have Different Effects on Pulse Wave Velocity and Cardiac Mass in Children

Background: High blood pressure (BP) and excess weight can lead to early cardiovascular organ damage already in children. Carotid-femoral pulse wave velocity (cf-PWV) is the non-invasive gold standard method for assessing aortic stiffness, while carotid-radial PWV (cr-PWV) provides information on the distensibility of the upper limb arteries. The aim of this study was to evaluate the relationship of BP and BMI z-scores with arterial stiffness and left ventricular mass index (LVMI) in a pediatric population. Methods: In 343 children (57.7% males; age ± SD 11.7 ± 2.9 years), systolic (SBP) and diastolic (DBP) BP, BMI, cf-PWV, cr-PWV and LVMI were measured. A multiple linear regression model was used to assess the impact of BMI and SBP (or DBP) z-scores on cf-PWV, cr-PWV and LVMI. Results: About 21% of children were normal weight, 34% were overweight and 45% obese. Adjusted for possible confounders, SBP and DBP z-scores were significantly associated with cf-PWV (p < 0.001), while only DBP z-scores were related to cr-PWV (p < 0.01). BMI was neither associated with cf-PWV nor with cr-PWV values but was a strong predictor of LVMI (<0.001), whereas cardiac mass and BP z-scores were not related. Conclusions: Our study suggests that, in children, elevated BP values and excess weight may have different effects on the heart and the vessels in causing early cardiovascular alterations.

Cardiometabolic Health and Carotid-Femoral Pulse Wave Velocity in Children: A Systematic Review and Meta-Regression

OBJECTIVE

To identify, in children the normal rate of carotid-femoral pulse wave velocity (cfPWV) progression, and whether presence of cardiometabolic risk factors is associated with cfPWV.

STUDY DESIGN

Electronic databases (PubMed, Google Scholar) were searched from inception to May 2018, for all studies which reported cfPWV in children (<19 years of age). Random effects meta-regression quantified the association between time (years) and cfPWV, and a systematic review was performed to determine whether cardiometabolic risk factors are associated with cfPWV.

RESULTS

Data from 28 articles were eligible for inclusion, including 9 reference value (n = 13 100), 5 cardiovascular risk (n = 5257), 10 metabolic risk (n = 2999), and 8 obesity-focused (n = 8760) studies. Meta-regression findings (9 studies) showed that the increase in cfPWV per year (age) was 0.12 m/second (95% CI, 0.07-0.16 m/second) per year, and when stratified by sex the CIs overlapped. Systematic review findings showed that cardiometabolic risk factors were positively associated with cfPWV, including positive associations with blood pressure, impaired glucose metabolism, and metabolic syndrome. However, obesity was not consistently associated with cfPWV.

CONCLUSIONS

Arterial stiffness in children progresses with age and is associated with cardiometabolic risk factors. Although further longitudinal studies are warranted, the presented reference data will be valuable to epidemiologists tracking children, and to scientists and clinicians prescribing therapies to mitigate risk in a population that is increasingly more vulnerable to cardiovascular disease.

Comparison of the SphygmoCor XCEL device with applanation tonometry for pulse wave velocity and central blood pressure assessment in youth

BACKGROUND

Vascular phenotype by assessing carotid-femoral pulse wave velocity (cf-PWV) and central SBP (cSP) in the young could be used as an intermediate cardiovascular outcome measure. Tonometry is considered the gold-standard technique, but its use is challenging in clinical practice, especially when used in children. The purpose of this study was to validate cf-PWV and cSP assessment with novel oscillometric device (SphygmoCor XCEL) in children and adolescents.

METHODS

cf-PWV and cSP were measured in 72 children and adolescents aged 6-20 years. Measurements were performed by applanation tonometry and by the SphygmoCor XCEL device at the same visit under standardized conditions. Regression analysis and Bland-Altman plots were used for comparison of the tonometer-based with oscillometric-based method.

RESULTS

Mean cf-PWV measured by applanation tonometry was 4.85 ± 0.81 m/s and measured by SpygmoCor XCEL was 4.75 ± 0.81 m/s. The mean difference between the two devices was 0.09 ± 0.47 m/s (P = NS). cSP measured by SpygmoCor XCEL was strongly correlated with cSP measured by applanation tonometry (R = 0.87, P < 0.001). Mean cSP measured by applanation tonometry was 103.23 ± 9.43 mmHg and measured by SpygmoCor XCEL was 103.54 ± 8.87 mmHg. The mean cSP difference between the two devices was -0.30 ± 3.34 mmHg (P = NS), and fulfilled the AAMI criterion 1. The estimated intersubject variability was 2.17 mmHg.

CONCLUSION

The new oscillometric SphygmoCor XCEL device provides equivalent results for cf-PWV and cSP values to those obtained by tonometry in children and adolescents. Thus, the SphygmoCor XCEL device could be appropriate for assessing cf-PWV and cSP in the pediatric population.

Pressure and Flow Relations in the Systemic Arterial Tree Throughout Development From Newborn to Adult

Objective: Distributed models of the arterial tree allow studying the effect of physiological and pathophysiological changes in the vasculature on hemodynamics. For the adult, several models exist; however, a model encompassing the full age range from newborn to adult was until now lacking. Our goal is to describe a complete distributed hemodynamic model for normal development from newborn to adult. Methods: The arterial system was modeled by 121 segments characterized by length, radius, wall thickness, wall stiffness, and wall viscosity. The final segments ended in three-element Windkessels. All parameters were adapted based on body height and weight as a function of age as described in the literature. Results: Pressures and flows are calculated as a function of age at sites along the arterial tree. Central to peripheral transfer functions are given. Our results indicate that peripheral pressure in younger children resembles central pressure. Furthermore, total arterial compliance, inertance and impedance are calculated. Findings indicate that the arterial tree can be simulated by using a three-element Windkessel system. Pulse wave velocity in the aorta was found to increase during development. Conclusions: The arterial system, modeled from newborn to adult bears clinical significance, both for the interpretation of peripheral measured pressure in younger and older children, and for using a Windkessel model to determine flow from pressure measurements.

Isolated systolic hypertension in the young: a position paper endorsed by the European Society of Hypertension

: Whether isolated systolic hypertension in the young (ISHY) implies a worse outcome and needs antihypertensive treatment is still a matter for dispute. ISHY is thought to have different mechanisms than systolic hypertension in the elderly. However, findings from previous studies have provided inconsistent results. From the analysis of the literature, two main lines of research and conceptualization have emerged. Simultaneous assessment of peripheral and central blood pressure led to the identification of a condition called pseudo or spurious hypertension, which was considered an innocent condition. However, an increase in pulse wave velocity has been found by some authors in about 20% of the individuals with ISHY. In addition, obesity and metabolic disturbances have often been documented to be associated with ISHY both in children and young adults. The first aspect to consider whenever evaluating a person with ISHY is the possible presence of white-coat hypertension, which has been frequently found in this condition. In addition, assessment of central blood pressure is useful for identifying ISHY patients whose central blood pressure is normal. ISHY is infrequently mentioned in the guidelines on diagnosis and treatment of hypertension. According to the 2013 European Guidelines on the management of hypertension, people with ISHY should be followed carefully, modifying risk factors by lifestyle changes and avoiding antihypertensive drugs. Only future clinical trials will elucidate if a benefit can be achieved with pharmacological treatment in some subgroups of ISHY patients with associated risk factors and/or high central blood pressure.

Clinical characteristics and risk of hypertension needing treatment in young patients with systolic hypertension identified with ambulatory monitoring

OBJECTIVE

The clinical significance of isolated systolic hypertension (ISH) in youth is controversial. One main confounding factor is the strong white-coat effect often observed in ISH patients. The aim of this study was to investigate the risk of hypertension needing pharmacological treatment in ISH identified with ambulatory 24-h blood pressure (24-h BP).

METHODS

We examined 1206, 18-45-year-old participants from the Hypertension and Ambulatory Recording VEnetia STudy. Based on 24-h BP, 269 participants were normotensive, 209 had ISH, 277 had isolated diastolic hypertension, and 451 had systolic-diastolic hypertension. The predictive role of ISH for incident hypertension was evaluated in Cox survival analyses, adjusting for risk factors and confounders.

RESULTS

ISH participants were more frequently young men active in sports, with lower heart rate and cholesterol. During a 6.9-year follow-up, 61.1% of participants developed hypertension. ISH participants had a nonsignificant increase in risk of hypertension compared with normotensive (reference group). In contrast, participants with diastolic hypertension (1.44; 1.13-1.85) or systolic-diastolic hypertension (2.04; 1.59-2.64) had a significant increase in risk. When the ISH participants were divided according to whether 24-h mean BP was normal (<97 mmHg) or high, ISH patients with normal mean BP had no increase in risk (1.01; 0.73-1.40), whereas those with high mean BP had a significant increase in risk (1.70; 1.16-2.49).

CONCLUSION

These data obtained with ambulatory BP monitoring show that in ISH people younger than 45 years, only mean BP is a predictor of future hypertension needing treatment, whereas the ISH status per se does not necessarily imply an increase in risk.

Predictors and Consequences of Pediatric Hypertension: Have Advanced Echocardiography and Vascular Testing Arrived?

PURPOSE OF REVIEW

Pediatric hypertension is relatively common and associated with future adult hypertension. Elevated blood pressure in youth predicts future adult cardiovascular disease and blood pressure control can prevent progression of pediatric kidney disease. However, pediatric blood pressure is highly variable within a given child and among children in a population.

RECENT FINDINGS

Therefore, modalities to index aggregate and cumulative blood pressure status are of potential benefit in identifying youth in danger of progression from a risk factor of subclinical phenotypic alteration to clinically apparent event. In this review, we advocate for the health risk stratification roles of echocardiographically assessed cardiac remodeling, arterial stiffness assessment, and assessment by ultrasound of arterial thickening in children and adolescents with hypertension.

Obesity and season as determinants of high blood pressure in a school-based screening study

This school-based screening study assessed the prevalence of high blood pressure (BP) levels according to the European Society of Hypertension (ESH) 2016 guidelines. Moreover, risk factors for BP elevation, and the effect of geographic and seasonal factors on BP screening were investigated. BP and anthropometric measurements were obtained from 2832 children and adolescents, aged 6-18 years, during the period 2013-2016. Three BP measurements were performed using a mercury sphygmomanometer, and the mean of the last two was used for the analysis. Obesity was defined according to the International Obesity Task Force (IOTF) criteria. The prevalence of high-normal BP/hypertension and overweight/obesity was 3.7%/0.9%, and 22.9%/8.5%, respectively. The majority of the participants presenting high BP (≥90th percentile) were overweight or obese. Increased prevalence of high BP was observed during spring (5.5%) and winter (5%) compared with 2.5% in autumn (P<0.05). SBP z scores were higher in males, during spring and summer, and in urban areas. In conclusion, a low rate of high-normal and hypertensive BP levels was found despite the high prevalence of overweight and obesity. Overweight and obesity were associated with higher BP levels, but there was also a seasonal difference in the prevalence of high BP levels.

Central systolic blood pressure and central pulse pressure predict left ventricular hypertrophy in hypertensive children

BACKGROUND

Central systolic and pulse pressures are stronger predictors of cardiovascular risk and hypertensive organ damage than brachial blood pressure. It is suggested that isolated systolic hypertension typically seen in adolescents is associated with normal central blood pressure and does not lead to organ damage and this phenomenon is called spurious hypertension.

METHODS

We assessed the prevalence of spurious hypertension and analyzed utility of pulse wave analysis as determinant of hypertensive organ damage in 294 children (62 girls; 15.0 ± 2.4 years) diagnosed as primary hypertension. White coat hypertension, ambulatory prehypertension, ambulatory hypertension, and severe ambulatory hypertension were diagnosed in 127, 29, 41, and 97 patients, respectively.

RESULTS

Normal central blood pressure was found in 100% in patients with white coat hypertension, 93% in pre-hypertensives, 51.2% in those with ambulatory hypertension, and 27.8% with severe ambulatory hypertension (p = 0.0001). Children with severe ambulatory hypertension had higher central systolic and pulse pressure, pulse wave velocity, and greater prevalence of left ventricular hypertrophy than white coat and prehypertensive children (p < 0.05). Left ventricular mass index and carotid intima-media thickness correlated with central systolic and pulse pressure (p < 0.05 for all). Receiver operating curve area was similar for augmentation pressure (0.5836), 24-h ambulatory systolic blood pressure (0.5841), central systolic blood pressure (0.6090), and central pulse pressure (0.5611) as predictors of left ventricular hypertrophy.

CONCLUSIONS

These findings suggest that pulse wave analysis is complementary to ambulatory blood pressure monitoring in assessment of risk of organ damage in hypertensive adolescents.

Mechanisms of pulse pressure amplification dipping pattern during sleep time: the SAFAR study

The difference in pulse pressure (PP) between peripheral arteries and the aorta, called pulse pressure amplification (PPamp), is a well-described physiological phenomenon independently associated with cardiovascular events. Recent studies suggest that it exhibits circadian variability. Our aim was to detect the factors associated with the circadian variability of PPamp. In 497 consecutive subjects (aged 54 years, 56.7% male, 79.7% hypertensives), we assessed the circadian pattern of peripheral and central arterial hemodynamics by 24-hour evaluation of brachial and aortic blood pressure (BP), augmentation index (AI), and pulse wave velocity (PWV) using a validated oscillometric device (Mobil-O-Graph). All parameters exhibited a circadian variation. Sleep dipping (decrease) pattern was observed for PPamp, brachial and aortic systolic BP, mean BP, and PWV, whereas a rising pattern (higher sleep than wake values) was observed for brachial PP, aortic PP, and AI. The factors independently associated with the less sleep dipping in PPamp were older age, lower height, the use of antihypertensive medication, and sleep decrease in arterial stiffness (PWV), whereas female gender, the presence of hypertension, sleep increase of pressure wave reflections (AI), sleep decrease in heart rate, and mean BP were associated with a greater sleep-dipping in PPamp. These data provide further pathophysiological understanding of the mechanisms leading to PPamp dipping. Several implications regarding the clinical use of the aortic and brachial BP, especially during sleep time, are raised that should be addressed in future research.

2016 European Society of Hypertension guidelines for the management of high blood pressure in children and adolescents

Increasing prevalence of hypertension (HTN) in children and adolescents has become a significant public health issue driving a considerable amount of research. Aspects discussed in this document include advances in the definition of HTN in 16 year or older, clinical significance of isolated systolic HTN in youth, the importance of out of office and central blood pressure measurement, new risk factors for HTN, methods to assess vascular phenotypes, clustering of cardiovascular risk factors and treatment strategies among others. The recommendations of the present document synthesize a considerable amount of scientific data and clinical experience and represent the best clinical wisdom upon which physicians, nurses and families should base their decisions. In addition, as they call attention to the burden of HTN in children and adolescents, and its contribution to the current epidemic of cardiovascular disease, these guidelines should encourage public policy makers to develop a global effort to improve identification and treatment of high blood pressure among children and adolescents.

Office Pulse Pressure Is a Predictor of Favorable Outcome in Young- to Middle-Aged Subjects With Stage 1 Hypertension

The role of pulse pressure in young individuals remains controversial. The aim of the present study was to investigate the clinical significance of elevated pulse pressure in young- to middle-aged subjects screened for stage 1 hypertension. We examined 1241 subjects (mean age, 33.1±8.4 years) from the HARVEST (Hypertension Ambulatory Recording Venetia Study), during a median follow-up of 12.1 years. To evaluate the predictive value of pulse pressure and mean blood pressure for future hypertension needing treatment and for cardiovascular events, participants were grouped into pressure tertiles. Significant determinants of pulse pressure were male sex (P=0.029), younger age (P<0.001), physical activity (P=0.003), heart rate (P<0.001), systolic white coat effect (P<0.001), and stroke volume (n=829; P<0.001). During follow-up, 65.1% of participants developed hypertension requiring pharmacological treatment and 5.1% experienced a cardiovascular event. Participants in the highest pulse pressure tertile had a reduced risk of incident hypertension compared with those of the bottom tertile (hazard ratio, 0.75; 95% confidence interval, 0.62-0.91; P=0.003). In contrast, participants in the top mean blood pressure tertile had an increase in risk (1.91; 1.57-2.33; P<0.001). In addition, participants in the highest pulse pressure tertile had a reduced risk of cardiovascular events (0.35; 0.17-0.73; P=0.005) and those in the top mean blood pressure tertile had an increase in risk (3.06; 1.32-7.09; P=0.009). Our data show that in subjects <45 years, only mean blood pressure is a predictor of adverse outcome whereas high pulse pressure even carries a reduced risk.

Isolated Systolic Hypertension in Young Individuals: Pathophysiological Mechanisms, Prognostic Significance, and Clinical Implications

Isolated systolic hypertension (ISH) is the most common form of hypertension in older persons and its predictive value for adverse outcome is well known. However, ISH can be frequently found also in young individuals, especially among males, but its prognostic significance in this setting is still controversial. Increased large artery stiffness is the main determinant of ISH in elderly patients whereas the mechanisms that lead to ISH in the young are still debated. According to some authors ISH in youth is a totally benign condition that can be called "spurious hypertension" a phenomenon due to enhanced pulse pressure amplification of the pulse wave from central to peripheral sites. According to others the main determinant of ISH in young individuals is increased sympathetic activity and the consequent hyperkinetic state characterized by elevated heart rate and stroke volume. This phenomenon is often amplified by a powerful alarm reaction to the medical visit. However, recent research has shown that ISH in the young is a heterogeneous condition and that in some individuals also increased arterial stiffness can play a role. Although ISH seems to be a benign condition chiefly in young men, only few longitudinal data assessing the association with adverse outcomes are available. Future studies with long term follow-up are needed to better understand the clinical significance of this condition.