Ambulatory Blood Pressure Monitoring in Children and Adolescents: Coming of Age?

Evaluation of endothelial dysfunction in hypertensive children and adolescents

BACKGROUND

Atherosclerotic changes can be attributed to early endothelial damage in individuals with hypertension. We aimed to explore the relationship between endothelial dysfunction and hypertension in newly diagnosed children without end-organ damage, considering carotid intima-media thickness (CIMT), flow-mediated dilatation (FMD), and functional capillaroscopy parameters. We also analyzed the differences between dipper and non-dipper patients.

METHODS

In this cross-sectional study, 20 patients diagnosed with essential hypertension with no target organ damage, and 20 age and sex-matched healthy volunteers were enrolled. The patient group comprised newly diagnosed individuals not receiving antihypertensive treatment. Hypertensive patients were divided into two groups (dipper and non-dipper patients). The measurements of CIMT, brachial FMD, and functional capillaroscopy were performed before starting treatment.

RESULTS

Among the patients, 11 were boys, and 9 were girls, with a median age of 16.0 (2.13) years. Of 20 hypertensive patients, 10 were dipper and 10 were non-dipper. Significant differences were observed between the hypertensive patients and controls in terms of CIMT (p = 0.04), brachial artery FMD (p = 0.02), and functional capillary density (p < 0.001). Hypertensive patients exhibited increased CIMT, reduced brachial artery FMD, and lower capillary density. However, there were no differences between dippers and non-dippers regarding age, sex, height SDS, weight SDS, CIMT SDS, brachial artery FMD, and capillary density.

CONCLUSIONS

Understanding the vascular consequences associated with essential hypertension emphasizes the importance of early detection and management of hypertension. Herein, we have effectively highlighted significant endothelial changes through the analysis of three parameters in newly diagnosed children without apparent target organ damage.

Masked Hypertension in Healthy Children and Adolescents: Who Should Be Screened?

PURPOSE OF REVIEW

The goal is to review masked hypertension (MH) as a relatively new phenomenon when patients have normal office BP but elevated out-of-office BP. Firstly, it was described in children in 2004. It has received increased attention in the past decade.

RECENT FINDINGS

The prevalence of MH in different pediatric populations differs widely between 0 and 60% based on the population studied, definition of MH, or method of out-of-office BP measurement. The highest prevalence of MH has been demonstrated in children with chronic kidney disease (CKD), obesity, diabetes, and after heart transplantation. In healthy children but with risk factors for hypertension such as prematurity, overweight/obesity, diabetes, chronic kidney disease, or positive family history of hypertension, the prevalence of MH is 9%. In healthy children without risk factors for hypertension, the prevalence of MH is very low ranging 0-3%. In healthy children, only patients with the following clinical conditions should be screened for MH: high-normal/elevated office BP, positive family history of hypertension, and those referred for suspected hypertension who have normal office BP in the secondary/tertiary center.

The performance of an integrated model including retinal information in predicting childhood hypertension

BACKGROUND

The objective of this study was to examine the association of an integrated model (composed of retinal arteriolar caliber, height, and sex) with blood pressure (BP) among a group of Chinese children, and assess the predictive value of the integrated model for childhood hypertension.

METHODS

This study included 1460 candidates aged 12.634 ± 0.420 years. Height, weight, waist circumference, and BP were obtained and ophthalmological measurements were taken. The computer-imaging program (IVAN, University of Wisconsin, Madison, WI) was used to measure calibers of retinal vessels. Receiver-operating characteristic curve (ROC) analyses were performed to assess the accuracy of the integrated model as a diagnostic test of elevated BP in children.

RESULTS

The accuracy of the integrated model (assessed by area under the curve) for identifying elevated BP was 0.777 (95% confidence interval: 0.742-0.812). The optimal threshold of the integrated model for defining hypertension was 0.153, and the calculation formula for the specific predictive risk was: Logit (p/1 - p) = -5.666 - 0.261 × retinal arteriolar caliber + 0.945 × sex + 0.438 × height. In identifying elevated BP, the sensitivity and specificity were 0.711 and 0.736, respectively.

CONCLUSIONS

The model containing eye message is a comprehensive and relatively effective index to identify elevated BP in 12-year-old children, which can offer assistance to further understand childhood microcirculation disease.

IMPACT

We firstly incorporated retinal vascular diameter, sex, and height into one integrated model to identify hypertension in 12-year-old children. The current discrimination of hypertension in children is difficult. There have been some studies to simplify the diagnosis of children's hypertension, but they were limited to anthropometric measurements. We proposed a composed model containing microcirculation information to predict childhood hypertension. Based on the knowledge that microcirculation is not only a means to study the manifestations but also early pathogenic correlates of hypertension, the combined model containing microcirculation message as a method may provide new insights into the diagnosis of childhood hypertension.

Clinical and Immunological Profile of Anti-factor H Antibody Associated Atypical Hemolytic Uremic Syndrome: A Nationwide Database

Background: Atypical hemolytic uremic syndrome (aHUS), an important cause of acute kidney injury (AKI), is characterized by dysregulation of the alternative complement pathway. Autoantibodies to factor H (FH), a chief regulator of this pathway, account for a distinct subgroup. While high anti-FH titers predict relapse, they do not correlate well with disease activity and their functional characterization is required.

Methods: Of 781 patients <18-year-old of aHUS in the nationwide database from 2007 to 2018, 436 (55.8%) had anti-FH antibodies. Clinical features and outcome of patients managed in the last 6-year (n = 317) were compared to before (n = 119). In plasma samples of 44 patients, levels of serial circulating FH immune complexes (CIC), free FH, soluble terminal complement complex (sC5b-9), sheep red blood cell (SRBC) lysis and epitope specificity (n = 8) were examined. Functional renal reserve, ambulatory hypertension, left ventricular hypertrophy (LVH), and proteinuria were evaluated in a subset.

Results: Patients presented with markedly elevated anti-FH titers (10,633.2 ± 998.5 AU/ml). Management varied by center, comprising plasma exchange (PEX; 77.5%) and immunosuppression (73.9%). Patients managed in the last 6-year showed better renal survival at mean 28.5 ± 27.3 months (log rank P = 0.022). Mean anti-FH titers stayed 700–1,164 AU/ml during prolonged follow-up, correlating with CIC. Patients with relapse had lower free-FH during remission [Generalized estimating equations (GEE), P = 0.001]; anti-FH levels ≥1,330 AU/ml and free FH ≤440 mg/l predicted relapse (hazards ratio, HR 6.3; P = 0.018). Epitope specificity was similar during onset, remission and relapse. Antibody titer ≥8,000 AU/ml (HR 2.23; P = 0.024), time to PEX ≥14 days (HR 2.09; P = 0.071) and PEX for <14 days (HR 2.60; P = 0.017) predicted adverse renal outcomes. Combined PEX and immunosuppression improved long-term outcomes (HR 0.37; P = 0.026); maintenance therapy reduced risk of relapses (HR 0.11; P < 0.001). At 4.4±2.5 year, median renal reserve was 15.9%; severe ambulatory, masked and pre-hypertension were found in 38, 30, and 18%, respectively. Proteinuria and LVH occurred in 58 and 28% patients, respectively.

Conclusion: Prompt recognition and therapy with PEX and immunosuppression, is associated with satisfactory outcomes. Free-FH predicts early relapses in patients with high anti-FH titers. A significant proportion of impaired functional reserve, ambulatory hypertension, proteinuria and LVH highlight the need for vigilant long-term follow-up.

Prehypertension among 2.19 million adolescents and future risk for end-stage renal disease

OBJECTIVE

Persistent hypertension in adulthood is a leading cause of end-stage renal disease (ESRD). Whether lower blood pressure (BP) values, in the range of prehypertension, are also associated with future occurrence of ESRD is unclear. Even less clear is the potential risk of early prehypertension appearing in adolescence. To address this question, we examined whether BP measurements in the prehypertensive range at age 16-19 years predict adult ESRD.

METHODS

Medical data on 2194 635 16-19-year-old adolescents examined for medical fitness prior to military service from 1977 to 2013 were linked to the Israeli ESRD registry in this nationwide population-based cohort study. Incident cases of ESRD were recorded. Survival models were applied.

RESULTS

During 35 007 506 person-years of follow-up (median follow-up 16.8 years), there were 690 ESRD cases, with an overall incidence rate of 1.97 cases per 100 000 person-years. Examinees with elevated BP readings in the prehypertensive range (BP between the 90th and 95th percentiles or between 120 and 139/80-89 mmHg) had increased incidence of ESRD with a hazard ratio of 1.32 (95% confidence interval, 1.11-1.58) adjusted for year of birth, age at examination, sex, BMI, education, socioeconomic status, and country of origin. Hypertension (BP above the 95th percentile or above 140/90 mmHg) was associated with a hazard ratio of 1.44 (95% confidence interval, 1.17-1.79). A spline model demonstrated a nadir of risk at SBP values as low as 94 mmHg.

CONCLUSION

Asymptomatic, healthy adolescents with prehypertension have a 32% increased risk for subsequent ESRD, compared with adolescents with optimal BP.

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.

Pharmacologic Management of Pediatric Hypertension

Hypertension in children is common, and the prevalence of primary hypertension is increasing with the obesity epidemic and changing dietary choices. Careful measurement of blood pressure is important to correctly diagnose hypertension, as many factors can lead to inaccurate blood pressure measurement. Hypertension is diagnosed based on comparison of age-, sex-, and height-based norms with the average systolic and diastolic blood pressures on three separate occasions. In the absence of hypertensive target organ damage (TOD), stage I hypertension is managed first by diet and exercise, with the addition of drug therapy if this fails. First-line treatment of stage I hypertension with TOD and stage II hypertension includes both lifestyle changes and medications. First-line agents include angiotensin-converting enzyme (ACE) inhibitors, thiazide diuretics, and calcium-channel blockers. Hypertensive emergency with end-organ effects requires immediate modest blood pressure reduction to alleviate symptoms. This is usually accomplished with IV medications. Long-term reduction in blood pressure to normal levels is accomplished gradually. Specific medication choice for outpatient hypertension management is determined by the underlying cause of hypertension and the comparative adverse effect profiles, along with practical considerations such as cost and frequency of administration. Antihypertensive medication is initiated at a starting dose and can be gradually increased to effect. If ineffective at the recommended maximum dose, an additional medication with a complementary mechanism of action can be added.

Management of hypertension in children and adolescents

Hypertension has been recognized as an important health issue in the pediatric population over the past years. This emphasizes the need for an organized and effective plan for diagnosis and management. This review provides information to guide physicians through a structured approach to (1) screen children for hypertension during routine visits; (2) use normative blood pressure tables for diagnosis and classification; (3) perform a clinical evaluation to identify the presence of risk factors, comorbidities and/or target organ damage; and (4) initiate an individualized plan of care that includes follow-up blood pressure measurement, therapeutic lifestyle changes and - if necessary - pharmacological therapies.