Pediatric ambulatory blood pressure monitoring: diagnosis of hypertension

Evaluation of renal injury in children with a solitary functioning kidney

OBJECTIVE

Children with a solitary functioning kidney have an increased risk of developing renal injury that is hypothesized to be caused by glomerular hyperfiltration. In this study, we aimed to assess the early signs of renal injury and ambulatory blood pressure profiles in children with a solitary functioning kidney.

MATERIALS AND METHODS

Data of children with normal office blood pressure measurement and a solitary functioning kidney were reviewed (serum creatinine and urine albumin and β2 microglobulin excretions), and 23 age-, weight-, and height-matched healthy children were considered as a control group. The size of the kidney was measured by renal ultrasound, and the presence of compensatory hypertrophy was calculated for all the subjects. Also, the subjects were additionally assessed for blood pressure (BP) pattern and the presence of hypertension by 24-hambulatory blood pressure monitoring.

RESULTS

The solitary functioning kidney demonstrated compensatory hypertrophy in 36 out of the patients (86%) at a mean age of 14.0 (SD 3.0) years. Increased urine albumin and β2 microglobulinuria, which are signs of kidney damage, were found in 7 (17%) and 5(12%) patients. Compared with the controls, patients had significantly higher mean blood pressure standard deviation scores (p>0,001), and ambulatory blood pressure monitoring identified masked hypertension in 7 (17%) children and prehypertension in 6 (14%) patients. Therefore, renal injury, defined as the presence of hypertension and/or albuminuria and/or β2 microglobulinuria and/or hypertension, was present in 36% of all children with a solitary functioning kidney.

CONCLUSION

Children with a solitary functioning kidney need prolonged follow-up to detect early signs of renal injury and prevent end-organ damage later in life. Ambulatory blood pressure monitoring is an essential tool in the diagnosis and clinical management of solitary functioning kidney patients.

Comparison of Pediatric and Adult Ambulatory Blood Pressure Monitoring Criteria for the Diagnosis of Hypertension and Detection of Left Ventricular Hypertrophy in Adolescents

OBJECTIVE

To compare pediatric ambulatory blood pressure monitoring (ABPM) criteria with adult ABPM criteria for the diagnosis of hypertension and detection of left ventricular hypertrophy (LVH) in adolescents.

STUDY DESIGN

ABPM and echocardiography reports from adolescents age 13-21 years from 2015 to 2019 were analyzed. The concordance of hypertension based on pediatric criteria (American Heart Association 2014) was compared with adult criteria from American College of Cardiology/American Heart Association 2017 (overall BP ≥125/75 mm Hg, wake BP ≥130/80 mm Hg, sleep BP ≥110/65 mm Hg) using the Cohen kappa statistic. Logistic regression, adjusted for body mass index z score, and receiver operating characteristic curves (ROCs) compared pediatric criteria vs adult criteria in predicting LVH (left ventricular mass index >95th percentile reference values and left ventricular mass index >51 g/m^2.7).

RESULTS

Of 306 adolescents, 140 (45.8%) had hypertension based on pediatric criteria vs 228 (74.5%) based on adult criteria; the agreement was poor (59.3%, n = 137, kappa = 0.41). A higher prevalence of LVH was captured by adult criteria only (n = 91) compared with pediatric criteria only (n = 3). Logistic regression found no significant differences between pediatric and adult criteria in the detection of LVH >95th percentile (OR 1.24, CI 0.66, 2.31, P = .51) or >51 g/m^2.7 (OR 1.06, CI 0.47, 2.40, P = .89). ROCs for pediatric criteria were not significant for detecting LVH >95th percentile (0.50, P = .91) or >51 g/m^2.7 (0.55, P = .45), whereas the ROC for adult criteria was significant for detecting LVH >95th percentile (0.59, P = .045) but not >51 g/m^2.7 (0.63, P = .07). Although all individuals with LVH >51 g/m^2.7 were hypertensive by adult criteria, 8 of these individuals were missed by pediatric criteria.

CONCLUSIONS

Adult criteria captured a higher prevalence of LVH and appeared to predict better LVH than pediatric criteria. A consideration to align ABPM criteria for diagnosing hypertension in adolescents with adult guidelines is warranted.

Ambulatory Blood Pressure Monitoring in Pediatrics

PURPOSE OF REVIEW

This is a review of ambulatory blood pressure monitoring (ABPM) use in pediatrics, summarizing current knowledge and uses of ABPM.

RECENT FINDINGS

Updated guidelines from the American Academy of Pediatrics have emphasized the value of ABPM. ABPM is necessary to diagnose white coat hypertension, masked hypertension, and nocturnal hypertension associated with specific conditions. There is growing evidence that ABPM may be useful in these populations. ABPM has been demonstrated to be more predictive of end-organ damage in pediatric hypertension compared to office blood pressure. ABPM is an important tool in the diagnosis and management of pediatric hypertension. Routine use of ABPM could potentially prevent early cardiovascular morbidity and mortality in a wide variety of populations.

Importance of ambulatory blood pressure monitoring in the diagnosis and prognosis of pediatric hypertension

The prevalence of high blood pressure (BP) at pediatric age has increased progressively, one of the causes of which is obesity. However, the dominant etiology in this age group is renal and/or cardiovascular pathology. Ambulatory blood pressure monitoring (ABPM) is the method of choice for the diagnosis of hypertension, especially in children at high cardiovascular risk. Its use is limited to children from five years of age. Choosing appropriate cuff size is key to obtaining correct blood pressure. The main indication for ABPM is to confirm the diagnosis of hypertension. It also allows the diagnosis of white coat hypertension (which may represent an intermediate stage between the normotensive phase and hypertension), or masked hypertension, associated with progression to sustained hypertension and left ventricular hypertrophy (LVH). Children with isolated nocturnal hypertension should be considered as having masked hypertension. BP load is defined as the percentage of valid measurements above the 95th percentile for age, gender, and height. Values above 25-30% are pathological and those above 50% are predictive of LVH. ABPM correlates with target organ damage, particularly LVH and renal damage. It is useful in the differentiation of secondary hypertension, since these children show higher BP load and less nocturnal dipping, and confirmation of response to therapy. Thus ABPM allows the diagnosis and classification of hypertension, provides cardiovascular prognostic information and identifies patients with intermediate phenotypes of hypertension.

Risk Factors in Adolescent Hypertension

Hypertension is a complex and multifaceted disease, with many contributing factors. While diet and nutrition are important influences, the confounding effects of overweight and obesity, metabolic and genetic factors, racial and ethnic predispositions, socioeconomic status, cultural influences, growth rate, and pubertal stage have even more influence and make diagnosis quite challenging. The prevalence of hypertension in adolescents far exceeds the numbers who have been diagnosed; studies have found that 75% or more go undiagnosed. This literature review summarizes the challenges of blood pressure classification in adolescents, discusses the impact of these confounding influences, and identifies actions that will improve diagnosis and treatment outcomes.

Aliskiren, the first direct renin inhibitor: assessing a role in pediatric hypertension and kidney diseases

This article provides a review of the role of aliskiren, a direct renin inhibitor, in pediatric hypertension and kidney diseases. Among the many mechanisms involved in regulating blood pressure, the renin-angiotensin-aldosterone system (RAAS) plays a major role. Additionally, the RAAS has been identified as a contributing factor to cardiovascular and renal diseases for more than three decades. The potential benefits of inhibiting the RAAS by aliskiren alone or in combination with other RAAS blockers (ACEIs, ARBs) seem to be theoretically promising. However, caution should be exercised in treating children, especially in those with significant chronic kidney disease until there is more evidence regarding the safety and efficacy of this new drug in the pediatric population from ongoing clinical trials.