Redefining hypertension in children and adolescents: A review of the evidence considered by the European Society of Hypertension and American Academy of Pediatrics guidelines

Defining childhood hypertension: is it too complicated? An evaluation of the potential impact of different approaches in an Australian paediatric population

OBJECTIVES

Current American Academy of Pediatrics (AAP) and European Society of Hypertension (ESH) thresholds defining hypertension in children use blood pressure (BP) normalised to age, sex and height. However, scare data exists regarding the relative importance of these variables age and height to accurately model the 95th quantile of BP. We hypothesised that height alone may fit the population data equally well compared to more complex definitions. We also compare the potential impact of various thresholds for defining hypertension in an Australian population.

METHODS

Longitudinal data from the Raine Study were used, with 2248 participants contributing 7479 valid BP values across the 3/5/10/14/17-year study visits. BP was measured after 5 min rest, ≥3 times at each visit, using a Dinamap device. Quantile regression was used to predict the 95th percentile of BP, with nonlinear modelling of covariates through restricted cubic spline terms.

RESULTS

At a single visit, 6-16% of young children exceeded the ESH threshold and 12-23% the AAP threshold. The transition to fixed thresholds (≥13 years AAP, ≥16 years ESH), increased the number of males (AAP only) and reduced the number of females considered hypertensive. A quantile regression model constructed with Raine Study data using height-only as the explanatory variable better predicted BP than the respective model using age-only (or a combination of the two).

CONCLUSIONS

There may be large differences in the prevalence of hypertension according to AAP and ESH criteria, with a marked sex-discrepancy emerging from the point of fixed threshold application in adolescence. It may not be necessary to normalise BP by both age and height, the latter being a better predictor of childhood BP. Simpler methods may be preferable in clinical practice but require validation against clinical outcomes.

Association Between Elevated Body Mass Index and Cardiac Organ Damage in Children and Adolescents: Evidence and Mechanisms

INTRODUCTION

Although a number of pathophysiological aspects of childhood obesity have been reported, few information are available on obesity-related cardiac organ damage.

AIM

The present study was aimed at assessing the impact of anthropometric, blood pressure (BP) and metabolic variable on cardiac structure and function in youth.

METHODS

In 78 subjects aged 5-16 years attending the outpatient clinic of cardiovascular risk (Valencia, Spain) anthropometric and metabolic variables, clinic and ambulatory BP and echocardiographic parameters were assessed. Subjects were also classified according to the presence of insulin resistance.

RESULTS

Subjects mean age (± SD) amounted to 12.03 ± 2.4 years and males to 53.8%. Ten subjects were normoweight, 11 overweight, 39 obese, and 18 severely obese. No significant difference in office and ambulatory BP was detected among different bodyweight groups. A significant direct correlation was observed between left ventricular mass index (LVMI) and obesity markers [body mass index (BMI): r = 0.38, waist circumference (WC): r = 0.46, P < 0.04 for both]. Left ventricular hypertrophy, relative wall thickness and left atrial diameter were significantly related to BMI and WC. In contrast, office and ambulatory BP were unrelated to other variables, and differences in LVMI among different BP phenotypes were not significant. When partitioning the population by insulin resistance, LVMI, adjusted for confounders, was significantly greater in the insulin-resistant group.

CONCLUSIONS

In children and adolescents characterized by different body weight patterns, weight factors "per se" and the related insulin resistance state appear to represent the main determinants of LVMI and left ventricular hypertrophy, independently on BP values and BP phenotypes.

Hypertension in Children and Young Adults

Primary hypertension (PH) is most common during adolescence with increasing prevalence globally, alongside the epidemic of obesity. Unlike in adults, there are no data on children with uncontrolled hypertension and their future risk of hard cardiovascular and cerebrovascular outcomes. However, hypertension in childhood is linked to hypertensive-mediated organ damage (HMOD) which is often reversible if treated appropriately. Despite differing guidelines regarding the threshold for defining hypertension, there is consensus that early recognition and prompt management with lifestyle modification escalating to antihypertensive medication is required to ameliorate adverse outcomes. Unfortunately, many unknowns remain regarding pathophysiology and optimum treatment of childhood hypertension.

Patterns and predictors of elevated blood pressure and hypertension among primary school children in urban Kenya

OBJECTIVE

We examined the prevalence of elevated blood pressure (BP) and hypertension among 390 primary school children of different socioeconomic status (SES) in two urban settings in Kenya and explored the association between children's BP status and their sociodemographic characteristics, dietary behaviours and overweight/obesity status.

METHODS

Children's BP and anthropometric measurements were taken and parents, with the help of their children, completed questionnaires on the children's dietary behaviours. An average of three BP readings was used to calculate BP percentiles by age, sex and height. BMI-for-age z-scores, waist-circumference-to-height ratio and the sum of skinfold measures were calculated. We utilized prevalence ratio analysis to examine the association between BP and sociodemographic characteristics, dietary behaviours and overweight/obesity.

RESULTS

About 9% of the school children had elevated BP and 33% had stage 1 hypertension. Among overweight children, the proportion of children with elevated BP was 1.85-fold greater and the proportion of children with hypertension was 1.83-fold greater compared with children with healthy body weight. Similar patterns of significant associations were seen among obese children, children with central obesity and children with high total skinfold values. The proportion of children with hypertension was 1.42-fold greater among children with high frequency of consumption of chips/crisps compared with children with lower frequency of consumption.

CONCLUSION

These results increase our understanding BP patterns and determinants among school children in Kenya and can help inform noncommunicable disease prevention efforts.

Prevalence and risk factors associated with different comorbidities in obese children and adolescents

INTRODUCTION

Different obesity-related comorbidities already present in childhood, such as: vitamin D deficiency, impaired carbohydrate metabolism, dyslipidaemia, arterial hypertension and non-alcoholic steatohepatitis. In this study, we aim to analyse the prevalence of comorbidities and to determine the predictive factors that affect these comorbidities.

MATERIAL AND METHODS

Anthropometric, demographic and biochemical variables were collected from obese patients between six and 18 years of age. Subsequently, a statistical analysis was performed to describe the characteristics of the patients and the prevalence of comorbidities, as well as their predictive factors.

RESULTS

A total of 158 obese children (76 boys and 82 girls) with a mean age at diagnosis of 12.48 years and a BMI Z-score of +3.24 SDS were included. The most prevalent comorbidities were vitamin D deficiency (64.2%), insulin resistance (45.1%), dyslipidaemia (32.2%), hyperuricaemia (18.5%) and arterial hypertension (15%). Age, BMI Z-score, percentage of fat mass and male sex have been found to be predictors of these comorbidities.

CONCLUSION

Obese children and adolescents have a high prevalence of comorbidities. Once the diagnosis of obesity has been established, it would be very useful to identify early those patients with a higher risk of comorbidities, knowing their relationship with sex, age, BMI Z-score, percentage of fat mass and pubertal stage.

Comparison of the 2017 American Academy of Pediatrics with the fourth report and the 2016 European Society of Hypertension guidelines for the diagnosis of hypertension and the detection of left ventricular hypertrophy in children and adolescents: a systematic review and meta-analysis

BACKGROUND AND OBJECTIVES

In 2017, the American Academy of Pediatrics (AAP) recommended new blood pressure (BP) thresholds for the diagnosis of hypertension in children and adolescents. We assessed the impact of the AAP guideline, as compared to the Fourth Report and the 2016 European Society of Hypertension guidelines (ESH), on the prevalence of hypertension and the detection of left ventricular hypertrophy (LVH).

METHODS

We systematically searched for studies evaluating the impact of the 2017 AAP guidelines on the prevalence of hypertension and LVH compared with the Fourth Report or the 2016 ESH guidelines. Meta-analysis was performed to compare the overall risk of LVH between the guidelines. We used a random-effects model to synthesize quantitative data.

RESULTS

We included 18 observational studies in the systematic review with an overall moderate to high risk of bias. The AAP guideline identified more children with hypertension than the Fourth Report and the ESH guidelines. In the meta-analysis of three observational studies, the guidelines revealed similar associations with LVH [odds ratio (OR) = 3.89, 95% confidence interval (95% CI) 1.68-8.99 for AAP and OR = 3.19, 95% CI 1.14-8.88 for Fourth Report/ESH guidelines]. Qualitative analysis of two observational studies revealed similar predictive value of the guidelines for LVH in adult life.

CONCLUSION

Despite the higher prevalence of hypertension frequently reported by the adoption of AAP guideline BP thresholds compared with Fourth Report and the ESH guidelines, the new thresholds have not been proved to advance assessment of cardiovascular risk in terms of LVH currently the most accepted subclinical marker in youth.

Difference in hypertension prevalence applying three childhood hypertension management guidelines in a national cohort study

The European Society of Hypertension (ESH) and American Academy of Pediatrics (AAP) recently updated their childhood hypertension management guidelines. We aimed to compare the hypertension prevalence determined using the two aforementioned guidelines and Fourth Report in a national cohort study. This 4.6-year follow-up study included 4276 children who had participated in the China Health and Nutrition Study. At baseline and during a follow-up survey, hypertension was defined using the three guidelines. We calculated the pediatric hypertension prevalence in at least one survey and in both surveys as the number of participants identified as hypertensive in at least one survey or in both surveys divided by 4276, respectively. Using Mc Nemar's test, we determined that the prevalence of pediatric hypertension differed significantly according to AAP vs. ESH guidelines and Fourth Report at the baseline (8.3% vs. 5.0% and 5.0%, respectively; reference, AAP; P_s < 0.001 for AAP vs. ESH guidelines and Fourth Report) and follow-up surveys (14.5% vs. 5.0% and 6.0%, respectively; reference, AAP; both P_s < 0.001), as well as among those detected with hypertension in at least one survey (21.0% vs. 9.4% and 10.4%, respectively; reference, AAP; both P_s < 0.001) and both surveys (1.8% vs. 0.5% and 0.6%, respectively; reference, AAP; both P_s < 0.001). We obtained similar results when using the three guidelines to define childhood elevated blood pressure. Our findings confirm the higher prevalence of pediatric hypertension using AAP guideline than those using ESH guideline and Fourth Report. Consequently, childhood hypertension management guidelines should be selected and used with caution.

Obesity-Related Hypertension in Pediatrics, the Impact of American Academy of Pediatrics Guidelines

The prevalence of primary hypertension in pediatric patients is increasing, especially as a result of the increased prevalence of obesity in children. New diagnostic guidelines for blood pressure were published by the American Academy of Pediatrics (AAP) in 2017 to better define classes of hypertension in children. The aim of our study is to evaluate the impact of new guidelines on diagnosis of hypertension in pediatrics and their capacity to identify the presence of cardiovascular and metabolic risk. Methods: Retrospective clinical and laboratory data from 489 overweight and obese children and adolescents were reviewed. Children were classified according to the 2004 and 2017 AAP guidelines for systolic and diastolic blood pressure. Lipid profile and glucose metabolism data were recorded; triglyceride/HDL ratio (TG/HDL) was calculated as an index of endothelial dysfunction. Hepatic steatosis was detected using the ultrasonographic steatosis score. Results: Children with elevated blood pressure increased from 12.5% with the 2004 AAP to 23.1% with the 2017 AAP criteria (p < 0.001). There was a statistically significant increase in children with high blood pressure in all age groups according to the new cut-off values. Notably, the diagnosis of hypertension according to 2017 AAP criteria had a greater positive association with Hepatic Steatosis (rho 0.2, p < 0.001) and TG/HDL ratio (rho 0.125, p = 0.025). Conclusions: The 2017 AAP tables offer the opportunity to better identify overweight and obese children at risk for organ damage, allowing an earlier and more impactful prevention strategy to be designed.

Body Mass Index and Blood Pressure-to-Height Ratio in Predicting Incidence of Hypertension in Serbian Children

BACKGROUND

A new method using blood pressure-to-height ratio for diagnosing elevated blood pressure/hypertension in children has been introduced recently. We aimed to compare blood pressure-to-height ratio (BPHR) and Body Mass Index (BMI) in predicting incidence of hypertension (HTN).

METHODS

The sample consisted of 1133 boys and 1154 girls aged 7-15. We used the following equations for BPHR: systolic BPHR (SBPHR) = SBP (mm Hg)/height (cm) and diastolic BPHR (DBPHR) = DBP (mm Hg)/height (cm). In order to determine the accuracy of SBPHR, DBPHR and BMI as diagnostic tests for elevated blood pressure (elevated BP), we used the receiveroperating characteristic curve analyses.

RESULTS

The area under the curve (AUC) values for BMI ranged from 0.625 to 0.723 with quite low sensitivity rates from 62% to 72.5% and specificities from 58.2% to 67.3% showing a modest ability to identify children with elevated BP and HTN. On the contrary, BPHR showed a great predictive ability to identify elevated BP and HTN with AUC values of 0.836 to 0.949 for SBP and from 0.777 to 0.904 for DBP. Furthermore, the sensitivity ranged from 78.5% to 95.7%, and the specificity from 73.9% to 87.6%.

CONCLUSION

the current study showed that BPHR is an accurate index for detecting elevated BP and HTN in children aged 7 to 15 years and can be used for early screening.

Hypertension in pediatric patients admitted to inpatient ward at King Abdulaziz Universty Hospital in Saudi Arabia: Prevalence, causes, and outcomes

Background:

The secondary hypertension (HTN) is the predominant form of HTN in pediatrics. Renal diseases and renovascular anomalies are the most commonly reported causes. In this study, we aimed to identify the prevalence, causes, and outcomes of secondary HTN in Saudi Arabia.

Methods:

A retrospective study was conducted among 3,640 pediatric patients aged between 0 and 18 years, admitted to the pediatric nephrology ward at King Abdulaziz University Hospital, Jeddah, Saudi Arabia. The study has been approved by the ethics review committee of King Abdulaziz University.

Results:

Prevalence of secondary HTN due to renal disease was (77.0%). Most of the cases were diagnosed with stage 5 renal disease (78.3%). Small kidney size was frequently diagnosed (n = 29, 11.9%), followed by large kidney size (n = 26, 10.7%). One third of the cases (n = 79, 32.4%) were under control, 49 (20.1%) lost follow-up, and 24 (10.1%) deceased. A total of 61 (33.1%) patients progressed to end-stage renal disease and patientswere managed by different types of treatments.

Conclusion:

The prevalence of secondary HTN due to renal disease is considered to be high in pediatric patients admitted to King Abdulaziz University. Several renal diseases in the renal system are associated with secondary HTN mostly attriubuted to renal malformation. In addition, renal affection, cerebral infarction, bleeding, left ventricular hypertrophy, and valvular lesion are the highest reported complications in our population. Follow-up with ECHO and brain CT is highly recommended in pediatric HTN. Future studies on a larger sample and vigorous follow-up are recommended.

New Diagnostic Criteria for Hypertension in Children and Adolescents: Lights and Shadows

Pediatric hypertension (HTN) represents a challenging disease with a major cardiometabolic risk (CMR) burden from childhood to adulthood. In fact, it has been linked to cardiac and vascular damage even at pediatric age and recognized as an independent risk factor for HTN in adulthood. Therefore, HTN in children has gained remarkable scientific interest during the past decades. However, the availability of different diagnostic classifications complicates HTN definition. The Clinical Practice Guidelines released in 2017 updated the diagnostic criteria, by highlighting some important issues with clinical implications. Lowering the new cut-offs proposed by the CPG, as compared with those proposed by IV Report criteria, will increase the number of young people at risk of hypertension. However, evidence suggests that the CPG cutoff-points in further identifying subjects with an altered CMR profile. Currently, some issues are still debated such as the adoption of a fixed cut-off of BP ≥ 130/80 mmHg for children aged ≥ 13 years, or the adoption of criteria for cardiac damage derived from adults. Given the CMR burden of pediatric HTN, a better and early identification of children at higher HTN risk is strictly recommended in order to improve HTN management to reduce the cardiovascular risk in these youths.

Clinical assessment of primary and secondary hypertension in children and adolescents

The aim of this study was to compare the clinical features of patients with elevated blood pressure and to detect variables associated with the diagnosis of primary hypertension. We identified 383 (69%) hypertensive children (197 [51.5%] with primary hypertension, and 186 [48.5%] with secondary hypertension) out of 553 children referred to our clinic with a history of elevated blood pressure. The primary hypertension group was significantly older and had higher BMI, positive family history of hypertension, and lower prevalence of preterm birth compared with those with secondary hypertension. No difference was found between the two groups in terms of the frequency of target organ damage. Multiple regression analysis showed that a family history of hypertension, obesity, age over 10 years, elevated uric acid, and presence of higher systolic blood pressure values at admission were independent predictors of primary hypertension; therefore, these parameters can be considered important clues for diagnosing primary hypertension.

The challenge of simplifying blood pressure screening in children and adolescents

Simplified methods of blood pressure screening could facilitate the clinical routine of the primary care physicians and may increase adherence to pediatric hypertension guidelines. Blood-pressure-to-height ratios are appealing for the simplicity of data needed to evaluate a child's blood pressure status, including only office blood pressure values and height. In several epidemiological studies around the world blood-pressure-to-height ratios showed good predictive power in identifying children with high blood pressure in terms of area under the curve and sensitivity compared to the gold standard National High Blood Pressure Education Program blood pressure tables, but low positive predictive values meaning a high rate of false-positive cases and possibly increased subsequent work load for primary physicians. Finally, blood-pressure-to height ratios seem to be dependent to age, sex, and weight status. In conclusion, blood-pressure-to-height ratios need to be further improved and validated in different pediatric populations before routine clinical use.