Ambulatory blood pressure monitoring in children and adolescents: recommendations for standard assessment: a scientific statement from the American Heart Association Atherosclerosis, Hypertension, and Obesity in Youth Committee of the council on cardiovascular disease in the young and the council for high blood pressure research

Comparison of cystic fibrosis-related diabetes with type 1 diabetes based on a German/Austrian Pediatric Diabetes Registry

OBJECTIVE

The prevalence of cystic fibrosis-related diabetes (CFRD) has increased with improved life expectancy of patients. Clinical and care characteristics were compared with type 1 diabetes mellitus (T1DM) in a multicenter analysis of pediatric data.

RESEARCH DESIGN AND METHODS

Auxological and treatment data from 47,227 patients aged younger than 21 years with CFRD or T1DM in the German/Austrian Diabetes Prospective Documentation Initiative registry were analyzed by multivariable mixed regression modeling.

RESULTS

Diabetes onset (mean [interquartile range]) occurred later in individuals with CFRD (14.5 [11.8-16.3] years) than in individuals with T1DM (8.5 [4.9-11.8] years), with female preponderance in CFRD (59.1% vs. 47.5%; P < 0.01). CFRD patients had lower BMI standard deviation scores (-0.85 [-1.59 to -0.12] vs. +0.52 [-0.10 to +1.16]; P < 0.01) and lower HbA(1c) (6.87% vs. 7.97%; P < 0.01). Self-monitoring of blood glucose was more frequent in patients with T1DM (4.5 vs. 3.5; P < 0.01); 72% of CFRD patients received insulin. In insulin-treated patients, insulin dosage adjusted for age, sex, and diabetes duration differed significantly (T1DM: 0.79 IE per kilogram of body weight; CFRD: 0.83 IE per kilogram of body weight). Use of short-acting and long-acting insulin analogs was significantly more frequent in T1DM (47% vs. 39% and 37% vs. 28%; both P < 0.05). Metabolic control in CFRD patients without insulin was better compared with CFRD on insulin (HbA(1c): 6.00 vs. 7.12; P < 0.01), but duration of disease was significantly shorter (0.8 years [0.1-2.4] compared with 2.4 years [0.6-4.6]). There was no significant difference for BMI standard deviations scores between CFRD patients with or without insulin treatment.

CONCLUSIONS

Pediatric patients with CFRD show clear auxological and metabolic differences from those with T1DM, with different treatment choices.

Association between obesity and the severity of ambulatory hypertension in children and adolescents

The goal of our study was to analyze the association between obesity and the severity of ambulatory hypertension in obese children. A total of 109 patients with primary obesity ages 7 to 18 years (mean ± SD age 14.1 ± 3.1) were enrolled. Patients were divided into three groups according to body mass index (BMI) Z-scores: group 1 (n = 27): BMI >1.65 and < 3.28 standard deviation scores (SDS); group 2 (n = 55): BMI >3.29 and <4.91 SDS; group 3 (n = 27): BMI >4.92 SDS. Definition and staging of ambulatory hypertension was based on blood pressure (BP) levels and BP load, obtained from ambulatory BP monitoring (ABPM). Only 24% had ambulatory normotension, 25% had ambulatory prehypertension, 3% had hypertension, and 48% had severe ambulatory hypertension. The severity of hypertension increased significantly with the degree of obesity (P = .0027). Daytime systolic, diastolic, and mean arterial BPs increased significantly with increased BMI, whereas the nighttime pressure remained elevated regardless of the degree of obesity. Isolated nighttime hypertension was observed in 25% of patients and 38% were classified as nondippers. Almost 50% of children with obesity and hypertension detected on ABPM suffer from severe ambulatory hypertension. BMI is associated with the severity of ambulatory hypertension and the increase of daytime BP.

Hypertension in children and adolescents: epidemiology and pathogenesis

High blood pressure is one among the leading contributors to burden of disease globally. Approximately 54 % of stroke and 47 % of ischemic heart disease events worldwide were attributable to high blood pressure in the year 2001. There is deficiency of data on the long-term outcome of hypertension in children. In spite of this, there is sufficient evidence to suspect that the health risks of hypertension in pediatric patients are substantial. Hypertension in childhood is known to result in hypertension in young adulthood. The epidemiology of hypertension in children is well represented from various studies conducted across continents. Factors like methodological issues in measurement, socio demographic differences, adiposity levels and ethnicity appear to influence the distribution of blood pressure as well as prevalence of hypertension in children. The etio-pathogenesis of essential (primary) hypertension is multi-factorial in origin. Obesity, insulin resistance, activation of sympathetic nervous system, alterations in sodium homeostasis, renin-angiotensin system changes, changes in vascular smooth muscle structure and reactivity, high serum uric acid levels, genetic factors and fetal programming have been reported to contribute to this disorder. The causes of secondary hypertension vary with age. Renal disorders and coarctation of the aorta are the most common causes of hypertension in children up to age 6 y. In older children, renal parenchymal disease remains the most frequent cause of increased blood pressure. Other causes of hypertension in children are relatively rare and include systemic arteritis and certain tumours, endocrine dysfunction, and neurologic disorders.

Ambulatory blood pressure monitoring in Chinese children with obstructive sleep apnea/hypopnea syndrome

OBJECTIVE

Obstructive sleep apnea/hypopnea syndrome (OSAHS) is a common sleep problem. The aim of this study is to investigate the association between OSAHS and blood pressure (BP) in snoring children.

METHODS

Snoring children were recruited from January 2009 to December 2010. Clinical history was taken accompanied by a physical examination and polysomnography were performed. A child with an apnea/hypopnea index (AHI) greater than 5 hr(-1) or obstructive apnea index (OAI) greater than 1 hr(-1) was diagnosed as having OSAHS. Ambulatory BP monitoring was performed for each child. BP load, BP index and nocturnal BP dipping were calculated for each child.

RESULTS

One hundred forty-five children with snoring were recruited and 107 of them were diagnosed with OSAHS. There were no differences between those with or without OSA in age or gender distribution. The OSAHS children had higher mean nighttime systolic and diastolic BP, increased BP load, and decreased nocturnal BP dipping compared to the non-OSAHS children (SBP: P = 0.03, DBP: P < 0.001, BP load: P = 0.001, SBP dipping: P = 0.03, DBP dipping: P = 0.04). Multiple regression analysis showed that mean nighttime systolic BP was related to age, obesity, and oxygen desaturation index (ODI) (P = 0.04, 0.03, and 0.02 respectively), while mean nighttime diastolic BP was related to obesity and ODI (P = 0.03 and 0.04, respectively).

CONCLUSIONS

OSAHS children had a higher nocturnal BP than non-OSAHS children and dysregulation of BP control reflected by decreased nocturnal BP dipping. Frequency of oxygen desaturation, apneas, and obesity were related to BP.

A case of hypospadias, anterior and posterior urethral valves

This report outlines the case of a 3-year-old boy whose initial presentation was that of asymptomatic hypertension (lowest recording 148/90), found at preoperative check prior to stage 2-correction surgery for distal hypospadias. Upon diagnosis of true hypertension, an ultrasound of the child's renal tract showed evidence of marked hydronephrosis and calyceal dilatation. On the background of deteriorating renal function (Urea 25.5 and Creatinine 188), a Micturating Cystourethrogram was performed, demonstrating posterior urethral dilatation. With difficulties controlling blood pressure, the child was transferred to Urology care, where resection of a posterior urethral valve (PUV) was undertaken. Despite this, renal function deteriorated further and re-cystoscopy identified an anterior urethral valve (AUV), which was also resected. Renal function, although improved, remains poor and blood pressure is controlled with two anti-hypertensives. To the publisher's knowledge, the association between hypospadias, PUVs and AUVs is as yet undocumented.

Ambulatory blood pressure and subclinical cardiovascular disease in patients with juvenile-onset systemic lupus erythematosus

BACKGROUND

The aim of this study was to evaluate the presence of subclinical cardiovascular disease (CVD) and its relation to risk factors, particularly hypertension in juvenile-onset systemic lupus erythematosus (SLE).

METHODS

A total of 24 patients with normal renal function were examined for subclinical CVD by using non-invasive methods, including the measurement of carotid intima-media thickness (IMT), carotid distensibility, aortic pulse wave velocity (PWV) and left ventricular mass (LVM). Blood pressure (BP) pattern and the presence of hypertension were assessed by 24-h ambulatory blood pressure monitoring (ABPM).

RESULTS

The patients had higher aortic PWV than the controls (p = 0.011). Increased carotid IMT was present in 48 % of the patients and reduced carotid distensibility in 17 %. Left ventricular hypertrophy (LVH) was present in 22 % of the patients. Eight patients were hypertensive; hypertensive patients had a significantly lower distensibility coefficient (DC)-SDS, higher aortic PWV and higher LVM index than the normotensive patients (p = 0.008, p = 0.023 and p = 0.001, respectively). Higher carotid IMT-standard deviation score (SDS) significantly correlated with higher nighttime diastolic BP-SDS (R (2)  = 0.204, p = 0.046); lower DC-SDS correlated with higher nighttime systolic BP-SDS (R (2)  = 0.290, p = 0.014). Increased aortic PWV was significantly associated with higher daytime systolic BP-SDS and elevated erythrocyte sedimentation rate (R (2)  = 0.607, p = 0.003 and p = 0.010, respectively). PWV was the only independent predictor of LVM index (R (2)  = 0.396, p = 0.004).

CONCLUSION

These results provide additional evidence for the presence of subclinical CVD and its relation to hypertension in juvenile-onset SLE. They also indicate a significant relation between LVH and increased arterial stiffness. It is also important to note that our findings reveal significant relationships between ambulatory BP and cardiovascular changes and underline the importance of ABPM to predict CVD.

Associations of World Trade Center exposures with pulmonary and cardiometabolic outcomes among children seeking care for health concerns

OBJECTIVE

Prior research on the physical health of children exposed to the World Trade Center (WTC) attacks has largely relied on parental report via questionnaire. We examined the impact of clinically-reported exposures on the physical health of children who lived and/or attended school in downtown Manhattan on September 11, 2001.

STUDY DESIGN

We performed a cross-sectional study of 148 patients who presented to the WTC Environmental Health Center/Survivors Health Program, and were ≤ 18 years old on September 11, 2001.

RESULTS

38.5% were caught in the dust cloud from the collapsing buildings on September 11; over 80% spent ≥ 1 day in their home between September 11 and 18, 2001; and 25.7% reported home dust exposure. New-onset nasal/sinus congestion was reported in 52.7%, while nearly one-third reported new gastroesophageal reflux (GERD) symptoms. Prehypertension or hypertension was identified in 45.5%. Multivariable regression with exposure variables, body mass index category, and age as covariates identified strongest associations of dust cloud with spirometry (17.1% decrease in maximum midexpiratory flow). Younger children experienced increased peripheral eosinophils (+0.098% per year, p=0.023), while older children experienced more new-onset GERD (OR 1.17, p=0.004), headaches (OR 1.10, p=0.011), and prehypertension (OR 1.09, p=0.024). Home dust exposure was associated with reduced high-density lipoprotein (-10.3mg/dL, p=0.027) and elevated triglycerides (+36.3mg/dL, p=0.033).

CONCLUSIONS

While these findings cannot be assumed to generalize to all children exposed to the WTC attacks, they strongly suggest the need for more extensive study of respiratory, metabolic, and cardiovascular consequences.

The rationale and design of Insight into Nephrotic Syndrome: Investigating Genes, Health and Therapeutics (INSIGHT): a prospective cohort study of childhood nephrotic syndrome

BACKGROUND

Nephrotic syndrome is one of the most commonly diagnosed kidney diseases in childhood and its progressive forms can lead to chronic kidney disease (CKD) and/or end-stage renal disease (ESRD). There have been few longitudinal studies among a multi-ethnic cohort to determine potential risk factors influencing disease susceptibility, treatment response, and progression of nephrotic syndrome. Temporal relationships cannot be studied through cross-sectional study design. Understanding the interaction between various factors is critical to developing new strategies for treating children with kidney disease. We present the rationale and the study design of a longitudinal cohort study of children with nephrotic syndrome, the Insight into Nephrotic Syndrome: Investigating Genes, Health and Therapeutics (INSIGHT) study. The specific aims are to determine: 1) socio-demographic, environmental, and genetic factors that influence disease susceptibility; 2) rates of steroid treatment resistance and steroid treatment dependence, and identify factors that may modify treatment response; 3) clinical and genetic factors that influence disease susceptibility and progression to CKD and ESRD; and 4) the interaction between the course of illness and socio-demographic, environmental, and clinical risk factors.

METHODS/DESIGN

INSIGHT is a disease-based observational longitudinal cohort study of children with nephrotic syndrome. At baseline, participants complete questionnaires and provide biological specimen samples (blood, urine, and toenail clippings). Follow-up questionnaires and repeat biological specimen collections are performed annually for up to five years.

DISCUSSION

The proposed cohort will provide the structure to test various risk factors predicting or influencing disease susceptibility, treatment response, and progression to CKD among children with nephrotic syndrome.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier NCT01605266.

Ambulatory and home blood pressure monitoring in children and adolescents: diagnosis of hypertension and assessment of target-organ damage

The prevalence of elevated blood pressure in children and adolescents is more common than previously believed and often represents the early onset of essential hypertension, particularly in adolescents. The definition of hypertension in children is based on distribution criteria and normalcy tables that provide blood pressure percentiles for each measurement method (office, ambulatory and home) according to the individual's age, gender and body size. Owing to the white coat and masked hypertension phenomena, ambulatory blood pressure monitoring is indispensable for the diagnosis of hypertension in children. Home blood pressure monitoring in children has been less well studied, and at present, treatment decisions should not be based solely on such measurements. Hypertension-induced preclinical target-organ damage (mainly echocardiographic left ventricular hypertrophy) is not uncommon in children and should be evaluated in all hypertensive children. Other indices of target-organ damage, such as carotid intima-media thickness, pulse wave velocity and microalbuminuria, remain under investigation in pediatric hypertension.

Non-dipping phenomenon in children with monosymptomatic nocturnal enuresis

PURPOSE

Monosymptomatic nocturnal enuresis is a common disorder seen in childhood, and many factors play a role in its etiopathology to varying degrees. The aim of our study was to investigate the possible association between nocturnal enuresis and 24-h blood pressure profiles of enuretic children.

METHODS

A total of 45 children ranging in age from 6 to 15 years with monosymptomatic nocturnal enuresis and 22 age-matched healthy controls were enrolled in our study. The blood pressure measurement was made at 30-min intervals during a 24-h period via an ambulatory blood pressure measurement device. Both groups underwent medical tests that included a complete blood count, blood biochemistry profile, urinalysis and blood renin-aldosterone levels, and all study subjects received an abdominal ultrasound.

RESULTS

Statistically significant high nocturnal blood pressure levels were observed in our patients with monosymptomatic nocturnal enuresis compared with the control group (p < 0.05). The mean values of the day-to-night difference (dipping) in the systolic and diastolic blood pressure of the patients were significantly lower than those of control group (p < 0.05).

CONCLUSION

Nocturnal enuresis should not only be accepted as a urinary system disorder. Possible systemic causative factors have to be examined, especially in patients that are resistant to first-line therapy. Based on the results of our study, we deduce that one of the factors that plays a role in the pathogenesis of enuresis nocturna is a non-dipping blood pressure profile (the "non-dipping" phenomenon).

Urinary angiotensinogen as a marker of intrarenal angiotensin II activity in adolescents with primary hypertension

BACKGROUND

Experimental and epidemiological studies have demonstrated that urinary angiotensinogen (AGT) is a novel biomarker for the intrarenal activity of the renin-angiotensin system in hypertension (HT). Several large-scale epidemiological studies have shown that an elevated serum uric acid (SUA) level is associated with HT. The aim of our study was to assess urinary AGT excretion and its correlation with SUA level, the lipid profile, and the body mass index (BMI) Z-score in hypertensive adolescents.

METHODS

Participants were divided into two groups: (1) the group with confirmed HT consisting of 55 subjects with primary HT and (2) the reference (R) group consisting of 33 subjects with white-coat HT. A commercial enzyme-linked immunosorbent assay (ELISA) kit was used to determine urinary AGT concentration.

RESULTS

The urinary AGT/creatinine (cr.) ratio in subjects in the HT group was significantly higher than that in the reference group (p < 0.01) and showed a strong positive correlation with SUA (r = 0.47, p < 0.01). The relationship between the AGT/cr. ratio and SUA levels after controlling for age, gender and BMI Z-score continued to show a significant association.

CONCLUSIONS

The most obvious finding to emerge from this study is that in adolescents with primary HT, the increased urinary excretion of AGT correlated with hyperuricemia, although large, multicenter studies are needed to confirm this observation.

High risk blood pressure and obesity increase the risk for left ventricular hypertrophy in African-American adolescents

OBJECTIVE

To examine the relative effects of high blood pressure (HBP) and obesity on left ventricular mass (LVM) among African-American adolescents; and if metabolic or inflammatory factors contribute to LVM.

STUDY DESIGN

Using a 2 × 2 design, African-American adolescents were stratified by body mass index percentile (body mass index <95th percentile = non-obese; ≥ 95th percentile = obese) and average blood pressure (BP) (normal BP <120/80 mm Hg; HBP ≥ 120/80). Glucose, insulin, insulin resistance, lipids, and inflammatory cytokines were measured. From echocardiography measures of LVM, calculated LVM index (LVMI) ≥ 95th percentile defined left ventricular hypertrophy (LVH).

RESULTS

Data included 301 adolescents (48% female), mean age 16.2 years, 51% obese, and 29% HBP. LVMI was highest among adolescents with both obesity and HBP. The multiplicative interaction of obesity and HBP on LVH was not significant (OR = 2.35, P = .20) but the independent additive associations of obesity and HBP with log-odds of LVH were significant; obesity OR = 3.26, P < .001; HBP OR = 2.92, P < .001. Metabolic and inflammatory risk factors were associated with obesity, but had no independent association with LVMI. Compared with those with average systolic BP (SBP) <75th percentile, adolescents with SBP from the 75th percentile to 90th percentile had higher LVMI (33.2 vs 38.7 g/m(2.7), P < .001) and greater LVH (18% vs 43%, P < .001), independent of obesity.

CONCLUSIONS

Prevalence of LVH is highest among African-American adolescents with average BP ≥ 120/80 mm Hg and obesity. There also is an independent association of LVMI with BP, beginning at the 75th SBP percentile.

Masked hypertension is prevalent in children with sickle cell disease: a Midwest Pediatric Nephrology Consortium study

BACKGROUND

The prevalence of hypertension and abnormal blood pressure (BP) patterns on 24-h ambulatory BP monitoring (ABPM) remains unknown in children with sickle cell disease (SCD).

METHODS

Thirty-eight asymptomatic children with sickle cell disease (SCD) (12 HbSS receiving routine care, 13 HbSC, and 13 HbSS receiving chronic transfusion therapy) underwent 24-h ABPM. Average clinic BP, demographic and biochemical characteristics were collected.

RESULTS

Median age was 13 years (range 11-16), body mass index (BMI) 19.1 kg/m(2) (range 18.2-21.1), and 50% were male. Seventeen subjects (43.6%) had ambulatory hypertension, while 4 (10.3%) were hypertensive based on their clinic BP. Mean systolic blood pressure (SBP) and diastolic blood pressure (DBP) dip were 8.3 ± 5.9% and 14.7 ± 7.6% respectively. Twenty-three subjects (59%) had impaired SBP dipping, 7 (18%) had impaired DBP dipping, and 5 (13%) had reversed dipping. Clinic and ABP classification were modestly correlated (rho = 0.38, P = 0.02).

CONCLUSION

Abnormalities in ABP measurements and patterns in children with SCD are prevalent and require more attention from heath care providers. ABPM is a valuable tool in identifying masked hypertension and abnormalities in circadian BP.

Vitamin D action: lessons learned from hereditary 1,25-dihydroxyvitamin-D-resistant rickets patients

PURPOSE OF REVIEW

Hereditary 1,25-dihydroxyvitamin-D [1,25(OH)(2)D(3)]-resistant rickets (HVDRR) is a rare genetic disease caused by generalized resistance to 1,25(OH)(2)D(3). Less than 100 cases are reported in the literature. These patients provide an experiment by nature enabling us to understand the role of vitamin D, especially in light of the ongoing debate concerning normal vitamin D levels and the supplement dosage that should be recommended. This article summarizes the role of vitamin D in calcium absorption, rennin-angiotensin system (RAS), and cardiac state in HVDRR patients.

RECENT FINDINGS

The precise spectrum of vitamin D activities can now be better evaluated by critical analysis of mouse models with targeted deletion of the gene encoding the vitamin D receptor (VDR). Of special interest is the unraveling of the role of VDR in calcium absorption and cardiac status in VDR-knockout mice. The facts that VDR-knockout mice up-regulate intestinal calcium absorption and skeletal mineralization independently of the VDR during pregnancy and lactation point to the existence of VDR-independent mechanisms that are involved in calcium absorption. The observation that mice with genetic disruption of the 1α-hydroxylase gene or of the VDR gene have an overstimulated RAS and consequently develop high blood pressure and cardiac hypertrophy raised concern about potential risks to the cardiovascular system in HVDRR patients.

SUMMARY

The current review summarizes the new understanding of the effects of vitamin D on calcium absorption, the RAS, and heart hypertrophy derived from studying HVDRR patients from infancy to their mid-30s.

The kidney in pediatric liver transplantation: an updated perspective

CKD continues to detract from the success of improved survival in pediatric liver transplantation, and its presence is likely under recognized. Here we review the literature regarding the prevalence, etiology, and management of renal dysfunction in pediatric liver transplant recipients. Long-term studies suggest the prevalence of CKD to be 25-38% by 5-10 yr post-transplant. While important, sole use of serum creatinine overestimates renal function in this population. Screening for and treatment of persistent proteinuria and hypertension as well as minimization of nephrotoxic insults are the mainstays to delay or prevent CKD progression. Office-based blood pressure measures are less sensitive than ABPM, which is specifically recommended by the American Heart Association for its ability to diagnose masked hypertension in pediatric liver transplant recipients. Long-term risk of CKD is predominantly secondary to CNI toxicity. CNI minimization protocols have shown promise in slowing progression of CKD while maintaining graft function, but large-scale randomized control trials with long-term follow-up are needed.

Uric Acid Reduction Rectifies Prehypertension in Obese Adolescents

Epidemiologic studies, animal models, and preliminary clinical trials in children implicate uric acid in the development of essential hypertension. Controversy remains as to whether the observations indicate a general mechanism or a surrogate phenomenon. We sought to determine whether uric acid is a causative mediator of increased blood pressure (BP) and impaired vascular compliance. We report a randomized, double-blinded, placebo-controlled trial comparing 2 mechanisms of urate reduction with placebo in prehypertensive, obese, adolescents, aged 11 to 17 years. Subjects were randomized to the xanthine oxidase inhibitor, allopurinol, uricosuric, probenecid, or placebo. Subjects treated with urate-lowering therapy experienced a highly significant reduction in BP. In clinic systolic BP fell 10.2 mm Hg and diastolic BP fell 9.0 mm Hg in treated patients compared with a rise of 1.7 mm Hg and 1.6 mm Hg systolic and diastolic BP, respectively in patients on placebo. Urate-lowering therapy also resulted in significant reduction in systemic vascular resistance. These data indicate that, at least in adolescents with prehypertension, uric acid causes increased BP that can be mitigated by urate lowering therapy.

White coat hypertension in children: not rare and not benign?

The clinical significance of white coat hypertension (WCH) remains uncertain. We aimed to evaluate the target organ damage (TOD) in children with essential hypertension (HTN) and WCH. We retrospectively analyzed the body mass index (BMI) and ambulatory blood pressure monitoring (ABPM) in 183 untreated children aged 5 to 19 years who were referred for assessment of hypertension and had secondary hypertension ruled out. Left ventricular mass index (LVMi) and carotid intima media thickness (CIMT) were analyzed in a subset of 106 children. WCH was found in 54/183 children (29.5%) who had normal mean arterial pressure (MAP), MAP load, and MAP day/night ratio. However, the mean+/-SD LVMi (g/m(2.7)) was identical in HTN and WCH patients (38.2+/-10.9 vs. 37.0+/-11.3, P=.59); it exceeded the 95th percentile in 40% HTN and 36% WCH patients (NS). The mean CIMT was significantly higher compared with normal, but not different between HTN and WCH; it exceeded the 95th percentile in 26% HTN and 29% WCH patients. WCH was found in up to 30% of children referred for HTN. Patients with WCH have TOD comparable to that found in HTN patients despite similar BMI, significantly lower average BP and BP load and a well-preserved BP dipping pattern.

Effect of placebo on ambulatory blood pressure monitoring in children

BACKGROUND

Ambulatory blood pressure monitoring (ABPM) has been proposed as a useful tool for more accurately diagnosing hypertension (HTN) and evaluating blood pressure (BP) response in pediatric anti-hypertensive trials. ABPM captures multiple BP measurements during routine daily activities and is thus an excellent method for identifying white-coat HTN. Additionally, ABPM measurements in adults do not demonstrate the placebo effect commonly seen with casual BP measurements, although this has yet to be evaluated in children. Therefore,, the aim of this study was to assess the effect of placebo on ABPM measurements in children.

METHODS

A total of 141 children aged 5-16 years with elevated BP were randomized into a multi-center, single-blind, cross-over trial. Subjects received a placebo pill prior to wearing a 24-h ABPM device at one of two visits separated by 1-2 weeks. Study procedures were otherwise identical at both visits.

RESULTS

Mean systolic and diastolic BP for all measured time periods were similar between visits, as was the number of children diagnosed with HTN at each visit.

CONCLUSION

Having confirmed HTN at baseline did not affect the impact of placebo on mean BP. If confirmed, this lack of placebo effect on ABPM measurements may allow for the design of direct comparison pediatric anti-hypertensive trials without a placebo arm.

Ambulatory blood pressure monitoring and cardiac hypertrophy in children with metabolic syndrome

BACKGROUND

The metabolic syndrome (MS), a cluster of potent risk factors for cardiovascular disease, is composed of insulin resistance, obesity, hypertension and hyperlipidemia. The aim of our study was to investigated the relationships between MS and left ventricular mass index (LVMI) in childhood MS. This study included 50 children and adolescents with MS aged between 7-18 years.

METHODS

Thirty age- and sex-matched healthy children served as a control group. The diagnosis of MS was made according to the criteria adapted from the World Health Organization. They underwent clinical examination with causal blood pressure (BP) measurements, 24-hour ambulatory blood pressure monitoring (ABPM) and echocardiogram. Patients underwent echocardiography to detect left ventricular hypertrophy (LVH). LVMI was calculated as left ventricular mass/height(2.7).

RESULTS

The mean age of MS group was 12.0 ± 3.1 years. The mean value of LVMI was 46.5 ± 11.5 g/m(2.7) in the MS group and it was significantly higher than those in the healthy children. The prevalence of severe LVH was 12 % using adult criteria (LVM > 51 g/m(2.7)) and 44 % using pediatric criteria (LVM > 95th percentile). The mean daytime systolic BP load (β = 0.315, p = 0.003) and HOMA-IR (β = 0.368, p = 0.006) were found as the independent predictors of LVMI.

CONCLUSIONS

In conclusion, LVH occurs commonly in pediatric MS and is associated with systolic hypertension and insulin resistance. LVMI should be measured routinely for the predicting of cardiovascular risks in these patients.

Twenty-four-hour ambulatory blood pressure monitoring detects a high prevalence of hypertension late after coarctation repair in patients with hypoplastic arches

OBJECTIVES

To determine by 24-hour blood pressure monitoring the risk of hypertension late after coarctation repair in patients with arch hypoplasia.

METHODS

Sixty-two of 116 consecutive patients (age, ≥10 years) who had coarctation repair and were quoted subjectively by the surgeon or the cardiologist to have arch hypoplasia at the time of the repair underwent a transthoracic echocardiogram and 24-hour blood pressure monitoring. Median age at repair was 11 days (range, 6-48 days). Mean preoperative z score of the proximal transverse arch was -2.43 ± 0.46. Eight patients had a repair via sternotomy (6 end-to-side anastomoses, 2 patch repairs) and 54 had a conventional repair via thoracotomy.

RESULTS

After a follow-up of 18 ± 5 years, 27% of the patients (17/62) had resting hypertension and 60% (37/62) had abnormal ambulatory blood pressure. Sensitivity of high resting blood pressure in detecting an abnormal 24-hour ambulatory blood pressure was 41%. Twenty patients had arch obstruction at last follow-up. Eighteen of them (90%) had abnormal ambulatory blood pressure. None of the patients operated on with end-to-side repair via sternotomy had reobstruction compared with 33% (18/54) of those repaired via thoracotomy.

CONCLUSIONS

Patients with a hypoplastic arch operated via thoracotomy have an alarming prevalence of hypertension. Regular follow-up with 24-hour ambulatory blood pressure monitoring is warranted, especially in patients who have had a smaller aortic arch at the time of the initial operation.

Hypertension and obesity: epidemiology, mechanisms and clinical approach

Obesity-related hypertension in pediatric patients is becoming more prevalent around the world as a consequence of the childhood obesity epidemic. Hypertension and the metabolic abnormalities associated with obesity will significantly increase the health risks for these children as they grow into adulthood. The pathophysiology of obesity-related hypertension is complex, and multiple potential mechanisms likely contribute to the development of higher blood pressure in obese children. These include hyperinsulinemia, activation of the renin-angiotensin-aldosterone system, stimulation of the sympathetic nervous system, abnormalities in adipokines such as leptin, direct effects of perinephric fat on the renal parenchyma, and cytokines acting at the vascular endothelial level. As in any child with elevated blood pressure, diagnostic evaluation should focus on confirmation of hypertension, determine if an underlying cause can be identified and whether hypertensive target organ damage is present. Therapy should begin with lifestyle modifications, but will often need to include one or more antihypertensive medications.

Ambulatory blood pressure in prehypertensive children and adolescents

BACKGROUND

Prehypertension is defined as blood pressure (BP) ≥ 90 th percentile, or ≥ 120/80 mmHg, but <95th percentile for age, sex, and height. Since the definition is made by conventional BP measurements and office BP can be quite variable, we studied whether prehypertension could be differentiated by ambulatory BP monitoring from normotension or hypertension (HTN) in children and adolescents.

METHODS

One hundred and fifty-eight children (84 boys and 74 girls, aged 6-17 years, median 12) were studied. According to the office BP values, they were divided into normotension (80), prehypertension (20), and HTN (58).

RESULTS

Systolic BP index and systolic daytime ambulatory BP (ABP) were significantly higher in prehypertensive patients than in normotensives and lower than hypertensives. When daytime ABP was used to diagnose HTN, four normotensive (5.0%), four prehypertensive (20.0%), and 27 hypertensive (46.6%) patients had HTN. Thus, in patients with prehypertension, the prevalence of masked HTN is significantly higher than in those with normotension. On the other hand, the prevalence of daytime ambulatory HTN is significantly lower, i.e., white-coat effect is more frequent, compared with hypertensive patients.

CONCLUSION

Prehypertension lies between normotension and HTN in ABP values as well and is a good candidate for identifying masked HTN. Our data emphasize the importance of identifying prehypertension in children and adolescents.

Benefit of BP Measurement in Pediatric ED Patients

Introduction. Obtaining blood pressures in pediatric emergency department patients is the standard of care; however, there is little evidence to support its utility. This prospective study assesses the benefit of BP acquisition in patients ≤5 years. Methods. Data were collected by the ED triage nurses on 649 patients in two community hospital EDs. Relationships between abnormal blood pressures and the patients' age, acuity, and calm versus not-calm emotional state were analyzed. Results. There were significant differences in the rate of elevated BPs in the calm and not-calm groups of patients. Overall, one- and two-year-old patients were more likely to have elevated BPs than those in other age groups. Very few patients in the sample had hypotension (1%). There was no relationship between Emergency Severity Index (ESI) acuity level and an abnormal BP. Nineteen percent of calm patients had elevated BPs, with 3.6% of patients in the stage two class of hypertension. Conclusions. There is limited benefit in obtaining BPs in children age of five or less regardless of whether the child is calm or not in ESI acuity levels 3 and 4.

Prehypertension in adolescents: risk and progression

In 2004, the National High Blood Pressure Education Program Working Group on High Blood Pressure in Children and Adolescents recommended a new designation of prehypertension for children with mildly elevated blood pressure (BP). This description was intended to help identify children most at risk for the development of persistent hypertension for whom targeted prevention programs would be most beneficial and was based largely on expert opinions and epidemiologic normal values. This review summarizes the knowledge that has been gained regarding the epidemiology and risk associated with prehypertension in adolescents since its inception and highlights future challenges in understanding and preventing the development of hypertensive disease in this population.

Ambulatory blood pressure patterns in children with chronic kidney disease

Ambulatory blood pressure (BP) monitoring (ABPM) is the best method of detecting abnormal BP in patients with chronic kidney disease (CKD), whose hypertension may be missed with casual BP measurements. We report ABPM findings in 332 children 1 year after entry in the Chronic Kidney Disease in Children cohort study. All of the subjects underwent casual and ambulatory BP measurement. BP was categorized based on casual and ABPM results into normal (42%), white-coat (4%), masked (35%), and ambulatory (14%) hypertension. Only half of the subjects had a normal ABPM. BP load was elevated (>25%) in 52% (n = 172), whereas mean BP was elevated in 32% (n = 105). In multivariate analysis, those using an angiotensin-converting enzyme inhibitor were 89% more likely to have a normal ABPM than those who did not report using an angiotensin-converting enzyme inhibitor (odds ratio, 1.89 [95% CI, 1.17-3.04]). For every 20% faster decline in annualized glomerular filtration rate change, the odds of an abnormal ABPM increased 26% (odds ratio, 1.26 [95% CI, 0.97-1.64]). A 2.25-fold increase in urine protein:creatinine ratio annualized change was associated with a 39% higher odds of an abnormal ABPM (odds ratio, 1.39 [95% CI, 1.06-1.82]). Abnormalities on ABPM are common in children with chronic kidney disease and are strongly associated with known risk factors for end-stage renal disease. Individuals on angiotensin-converting enzyme inhibitors were less likely to have abnormal ABPM, suggesting a possible therapeutic intervention. ABPM should be used to monitor risk and guide therapy in children with chronic kidney disease.

Blood pressure variability, prehypertension, and hypertension in adolescents

Medical conditions diagnosed during adolescence may have long term impacts on the health of an individual. As a result, identifying cardiovascular risk factors earlier in life such as prehypertension (pre-HTN) and hypertension (HTN) can have significant benefits across an individual’s lifespan. Diagnosing elevated blood pressure (BP) during adolescence can be difficult, partially due to the natural variability that occurs during this period of life. Levels of BP that define adolescent prehypertension/hypertension are provided as well as an abridged review of BP variability across research groups. Strategies for BP management of adolescents are considered, with the primary focus on nonpharmacologic interventions.

Correlation of blood pressure readings from 6-hour intervals with the daytime period of 24-hour ambulatory blood pressure monitoring in pediatric patients

Shorter-interval (6-hour) ambulatory blood pressure monitoring (ABPM) has been shown to correlate well with 24-hour ABPM in adults, but this has not been studied in children. The authors selected 131 patients aged 9 to 18 who underwent 24-ABPM from 2000-2008. Six-hour intervals beginning at different start times were compared with the daytime and 24-hour period, with subset analysis for normotensive and hypertensive patients. Concordance correlation coefficients (CCCs) were used to assess for agreement. Among normotensive patients, the mean difference between daytime and 6-hour intervals ranged from -0.1 mm Hg to 0.0 mm Hg for diastolic blood pressure (DBP) and -1.1 mm Hg to 0.6 mm Hg for systolic blood pressure (SBP) with CCCs of 0.88 to 0.93 for DBP and 0.93 to 0.96 for SBP. For hypertensive patients, mean difference ranged from -0.6 to 1.3 mm Hg for DBP and -0.8 to 1.1 mm Hg for SBP with CCCs of 0.89 to 0.98 for DBP and 0.86 to 0.95 for SBP. Shorter-interval monitoring correlates significantly with full daytime monitoring in children, allowing for assessment of blood pressure with improved convenience.

Pediatric ambulatory blood pressure monitoring: indications and interpretations

The prevalence of hypertension in children and adolescents is increasing, especially in obese and ethnic children. The adverse long-term effects of hypertension beginning in youth are known; therefore, it is important to identify young patients who need intervention. Unfortunately, measuring blood pressure (BP) is difficult due to the variety of techniques available and innate biologic variation in BP levels. Ambulatory BP monitoring may overcome some of the challenges clinicians face when attempting to categorize a young patient's BP levels. In this article, the authors review the use of ambulatory BP monitoring in pediatrics, discuss interpretation of ambulatory BP monitoring, and discuss gaps in knowledge in usage of this technique in the management of pediatric hypertension.

Hypertensive nephropathy in children - do we diagnose early enough?

BACKGROUND/AIMS

The aim was to evaluate the level of neutrophil gelatinase-associated lipocalin (NGAL), interleukin 18 (IL-18) and retinol binding protein (RBP) in children with primary hypertension and no features of hypertensive nephropathy.

METHODS

The study group consisted of 19 children (15 males) aged 14.8 ± 2.18 years with primary hypertension. Estimated glomerular filtration rate (eGFR) and albumin/creatinine ratio (ACR) were within the normal range. Mean blood pressure (BP) was 141/79 mmHg (mean systolic BP percentile was 98, mean diastolic BP percentile was 80). Ambulatory BP measurement (ABPM), blood and urine biochemical measurements and features of end organ damage were assessed. The control group consisted of 20 healthy children.

RESULTS

Hypertensive children showed significantly increased serum and urine NGAL concentration vs controls. Urine RBP was significantly higher in the study group vs controls. A positive correlation was found between urine NGAL and the index of mean systolic BP measured in ABPM, between urine IL-18 and the index of office diastolic BP, between serum NGAL and ACR, and between urine NGAL concentration and serum HDL.

CONCLUSION

In children with primary hypertension, increased serum and urine NGAL may reflect kidney injury earlier than typical markers of hypertensive nephropathy.

Liddle syndrome in a Serbian family and literature review of underlying mutations

Severe and reproducible low-renin hypertension responsive to salt restriction and amiloride-thiazide therapy in a 13-year-old otherwise asymptomatic boy suggested Liddle syndrome. This assumption was strengthened by a positive family history of hypertension poorly responsive to conventional treatment or sudden deaths under 40 years of age in four generations. DNA analysis of the beta and gamma subunits of the epithelial sodium channel revealed a heterozygous mutation c.C1852T (p.Pro618Ser) in the SCNN1B gene in the patient and in both his hypertensive mother and uncle. A PubMed search revealed 21 different disease-causing mutations reported to date, all but two clustering in the cytoplasmic C-terminal regions of either beta (16 mutations) or gamma (5) subunit, leading to a three- to eightfold increase in the amiloride-sensitive sodium current. Inter- and intrafamilial variability in both hypertension and hypokalemia were disclosed, which may not be obligatory among the subjects carrying a Liddle mutation.

CONCLUSION

Liddle syndrome should be considered as a cause of hypertension in children or adolescents particularly with suppressed renin activity. Early diagnosis and appropriately tailored treatment avoid complications of long-term unrecognized or inappropriately managed hypertension.

Control of hypertension in treated children and its association with target organ damage

BACKGROUND

The aim of our study was to investigate the control of hypertension (HT) in treated children using ambulatory blood pressure (BP) monitoring (ABPM).

METHODS

We retrospectively reviewed all ABPM studies in our center. Controlled HT was defined as systolic and diastolic BP index (patients' BP divided by the 95th percentile) at daytime and nighttime <1.0 or alternatively as BP load (percentage of BP readings above the 95th percentile) <25% in children on antihypertensive therapy.

RESULTS

A total of 195 ABPM studies were included. The mean age was 13.6 ± 4.0 years. One hundred and thirty two children had renoparenchymal HT, 10 renovascular (RVH), 10 endocrine, 4 cardiovascular, 29 primary (PH) and 5 children other forms of HT. 53% of all children had controlled HT. There was no difference in the prevalence of controlled HT between primary and secondary HT (52% and 53%) using the BP index criterion. Children with renoparenchymal HT had significantly better control of HT than children with RVH (58% vs. 20% P = 0.02). The use of angiotensin-converting enzyme inhibitors (ACEI) monotherapy was significantly more effective in controlling HT than the use of calcium-channel blockers (CCB, P = 0.02). The prevalence of left ventricular hypertrophy in children with uncontrolled HT (assessed in 58 patients) was significantly higher than in children with controlled HT (46% vs. 13%, P < 0.01).

CONCLUSIONS

This is the first pediatric study, to our knowledge, on BP control in hypertensive children using ABPM. It indicates that control of HT is inadequate in ~50% of treated children. Inadequate control of HT is associated with target organ damage in this population.

Reliability of resting blood pressure measurement and classification using an oscillometric device in children with chronic kidney disease

OBJECTIVE

To compare the reliability of blood pressure (BP) readings obtained with an oscillometric device with those obtained by auscultation and assess for differences in BP status classification based on the 2 techniques.

STUDY DESIGN

Resting BP was measured by auscultation and with an oscillometric device at the same encounter in 235 subjects enrolled in the Chronic Kidney Disease in Children study. Resting auscultatory BP values were averaged and compared with averaged oscillometric readings. BP agreement by the 2 methods was assessed using Bland-Altman plots, and BP status classification agreement was assessed by calculation of kappa statistics.

RESULTS

Oscillometric BP readings were higher than auscultatory readings, with a median paired difference of 9 mm Hg for systolic BP (SBP) and 6 mm Hg for diastolic BP (DBP). Correlation for mean SBP was 0.624 and for mean DBP was 0.491. The bias for oscillometric BP measurement was 8.7 mm Hg for SBP (P < .01) and 5.7 mm Hg for DBP (P < .01). BP status classification agreement was 61% for SBP and 63% for DBP, with Kappa values of .31 for SBP and .20 for DBP.

CONCLUSIONS

Compared with auscultation, the oscillometric device significantly overestimated both SBP and DBP, leading to frequent misclassification of BP status.

Abnormal circadian blood pressure regulation in liver transplanted children

HT is a frequent cardiovascular risk factor in liver transplant recipients. However, there are only few studies in the literature regarding the risk of HT in liver transplanted children. The aim of this study was to assess the 24 h BP profiles of liver transplanted patients and to compare the results with healthy children. ABPM was performed on 20 liver transplanted patients and 27 healthy children aged 7.1 ± 4.8 and 8.5 ± 2.9 yr, respectively. HT was defined as SDS > 1.64 (i.e., >95th percentile) adjusted for gender and height. The mean duration of post-transplant follow-up was 32 ± 19 months. Six (30%) patients were found to be hypertensive. The physiological nocturnal BP fall was attenuated significantly in the study group for diastolic BP (11.5 ± 6.1 mmHg vs. 17.7 ± 7.1 mmHg, p = 0.006). Specifically, the number of patients with high nighttime systolic and diastolic BP SDS (p = 0.02 and p = 0.004, respectively) as well as elevated nighttime systolic (p = 0.03) and diastolic (p = 0.003) BPLs was found to be significantly higher than those in the controls. Alteration of the "normal" circadian rhythm is very frequent in liver transplant recipients. Thus, it is recommended to perform ABPM on all liver transplanted children not to underdiagnose HT.

Oxidative stress in hypertensive children before and after 1 year of antihypertensive therapy

BACKGROUND

The relation between primary hypertension (PH), target organ damage (TOD) and oxidative stress (SOX) is not known.

METHODS

We assessed SOX in 86 children with PH before and after 12 months of standard non-pharmacological and pharmacological therapy based on renin-angiotensin system blockade.

RESULTS

Patients with left ventricular hypertrophy (LVH) and with carotid intima-media thickness (cIMT) >2SDS had higher thiobarbituric acid reactive substances (TBARS) concentrations in comparison to patients without LVH or with normal cIMT. Patients with metabolic syndrome (MS) had lower activity of gluthatione peroxidase, higher asymmetric dimethyloarginine (ADMA) and oxidized LDL cholesterol (oxyLDL) in comparison to patients without MS. TBARS correlated with left ventricular concentric hypertrophy, cIMT, albuminuria and SBP/24 h. ADMA and oxyLDL correlated with CRP and TG/HDL ratio. After 1 year of antihypertensive treatment blood pressure, TOD and prevalence of MS decreased. TBARS decreased and glutathione concentrations increased. The decrease of TBARS concentration correlated with the decrease of body mass index (BMI). Decrease of oxyLDL and ADMA correlated with increased insulin sensitivity, however markers of SOX did not correlate with BP decrease.

CONCLUSION

SOX in children with PH correlates with TOD, metabolic abnormalities, changes in fat amount and improvement of insulin sensitivity, but not with BP decrease.

Hypertension in children and adolescents

Pediatric hypertension (HTN) has become the focus of interest recently due to its increasing prevalence. This is mainly related to the increase in childhood obesity, although the current evidence suggests that other lifestyle factors, apart from obesity, contribute to high blood pressure (BP) in childhood. Traditionally, office BP measurements by the physician have been the cornerstone for the assessment of HTN in children. However, since the white coat and masked HTN phenomena are not rare in childhood, out-of-office BP measurements have significantly improved the accurate diagnosis of HTN and decision making. Ambulatory BP monitoring is regarded as indispensable for the evaluation of pediatric HTN, providing details not only for the staging for HTN, but also for the study of other ambulatory BP patterns. It should be pointed out that HTN in children and adolescents is associated with target-organ damage which is significant in terms of cardiovascular risk. The current knowledge, outlined in the present review, is expected to help in early and accurate diagnosis as well as in the management of HTN in children and adolescents.

Ambulatory blood pressure monitoring in children: imperfect yet essential

There has been increasing emphasis on hypertension and early cardiovascular disease in the pediatric age group over the past decade as a result of various factors, including the obesity epidemic and publication of new clinical guidelines. A key component of identifying children and adolescents with definite or potential hypertension is proper blood pressure (BP) measurement. While ambulatory blood pressure monitoring (ABPM) offers the potential for improved detection of youths at increased cardiovascular risk, it has not been widely adopted. This commentary highlights the crucial role of ABPM in the context of current trends, while at the same time identifying the current barriers to more widespread application of this technique. Chief among these is the lack of a robust, universally applicable database of pediatric ABPM normative values. Even in the absence of ideal normative data, ABPM can and should be widely applied, and a potential algorithm for such an approach is presented.

Ambulatory blood pressure status in children: comparing alternate limit sources

The American Heart Association has included alternate ambulatory blood pressure (ABP) limits for children published by Wühl in 2002. These updated limits employ the same pediatric cohort data as the previous ABP limits published by Soergel in 1997 but differ in analysis technique. The implications of changing ABP limit source on the diagnosis of hypertension has yet to be examined in a large pediatric cohort. We reviewed 741 ABP monitorings performed in children referred to our hypertension clinic between 1991-2007. Hypertension was defined as 24-h mean blood pressure ≥ 95 th percentile or 24-h blood pressure load ≥ 25%, by Soergel and Wühl limits separately. Six hundred seventy-three (91%) children were classified the same by both limit sources. Wühl limits were more likely than Soergel to classify a child as hypertensive (443 vs. 409, respectively). There was an increased classification of prehypertension and decreased white-coat hypertension by the Wühl method, whereas ambulatory and severe hypertension counts remained relatively the same by both limits sources. The use of either limit source will not significantly affect most clinical outcomes but should remain consistent over long-term research projects. Collection of new normative data from a larger, multiethnic population is needed for better measurement of ABP in children.

The role of obesity, salt and exercise on blood pressure in children and adolescents

The increasing trends of blood pressure (BP) in children and adolescents pose great concern for the burden of hypertension-related cardiovascular disease. Although primary hypertension in childhood is commonly associated with obesity, it seems that other factors, such as dietary sodium and exercise, also influence BP levels in children and adolescents. Several studies support that sympathetic nervous system imbalance, impairment of the physiological mechanism of pressure natriuresis, hyperinsulinemia and early vascular changes are involved in the mechanisms causing elevated BP in obese children and adolescents. Under the current evidence on the association of salt intake and BP, dietary sodium restriction appears to be a rational step in the prevention of hypertension in genetically predisposed children and adolescents. Finally, interventional studies show that regular aerobic exercise can significantly reduce BP and restore vascular changes in obese with hypertensive pediatric patients. This article aims to summarize previous studies on the role of obesity, salt intake and exercise on BP in children and adolescents.

Implications of nocturnal hypertension in children and adolescents with type 1 diabetes

OBJECTIVE

Diabetes is associated with atherogenic risk factors. Hypertension has a major influence on cardiovascular disease in diabetic patients. Ambulatory blood pressure monitoring (ABPM) is useful for identifying nocturnal hypertension. Carotid intima-media thickness (cIMT) is a good measure for identifying subclinical atherosclerosis. This study aimed to evaluate whether nocturnal hypertension affects atherosclerosis in children and adolescents with type 1 diabetes and to investigate the relationship between atherogenic risk factors and cIMT.

RESEARCH DESIGN AND METHODS

ABPM and cIMT were measured in 82 diabetic children and adolescents. We reviewed the hemoglobin A(1c) levels, 24-h urine microalbumin excretion, lipid profiles, and duration of diabetes. Nocturnal hypertension was defined as hypertension observed only at night.

RESULTS

Forty-three (52%) subjects were hypertensive, and 30 subjects were classified as having nocturnal hypertension. cIMT was higher in the nocturnal hypertensive group than in the normotensive group (0.44 ± 0.03 vs. 0.42 ± 0.04 mm, P = 0.026). Among children and adolescents with nonhypertensive blood pressure levels in clinic blood pressure monitoring, cIMT and daytime blood pressure were higher in the nocturnal hypertensive group. All ABPM parameters were significantly related to cIMT in multiple linear regression analysis.

CONCLUSIONS

This study showed significantly increased cIMT and daytime blood pressure in diabetic children and adolescents with nocturnal hypertension. ABPM may be a useful method for detecting the macrovascular complications of type 1 diabetes. Longitudinal studies are needed to find the causes of nocturnal hypertension and to evaluate the effect of nocturnal hypertension on atherosclerosis in type 1 diabetes.

Home blood pressure in children and adolescents: a comparison with office and ambulatory blood pressure measurements

AIM

To compare BP measurements of children and adolescents using different methods office BP (OBP), ambulatory BP monitoring (ABPM) and home BP measurement (HBPM) and to study their correlations.

METHOD

Individuals were evaluated between 5 and 15 years of age who had been referred because of a previous high BP. OBP was measured with the OMRON-705CP. Three measurements were carried out at 5-min intervals. HBPM were taken using the same device, two measurements at 5-min intervals in the morning and in the evening during 7 days. ABPM was performed using the SpaceLabs 90207 monitors.

RESULTS

A total of 109 children and adolescents were evaluated (9.82 ± 2.63 years), 52.3% boys, 56.9% non-white. The office systolic BP (SBP) was lower than in daytime ABPM (p < 0.001) but similar HBPM (p = 0.294), and the office diastolic BP (DBP) was lower than daytime ABPM (p < 0.001) and in HBPM (p = 0.035). The SBP and DBP at HBPM was lower than daytime ABPM (p < 0.001). Daytime ambulatory BP was more closely associated with home readings (SBP r = 0.731 and DBP r = 0.616) than with office's readings (SBP r = 0.653 and DBP r = 0.394).

CONCLUSION

The BP of children and adolescents varies depending on the place and manner of measurement. ABPM presents better correlation with HBPM than with the office measurements.

The renin-angiotensin system, blood pressure, and heart structure in patients with hereditary vitamin D-resistance rickets (HVDRR)

Vitamin D deficiency has been linked to hypertension and an increased prevalence of cardiovascular risk factors and disease. Studies in vitamin D receptor knockout (VDR KO) mice revealed an overstimulated renin-angiotensin system (RAS) and consequent high blood pressure and cardiac hypertrophy. VDR KO mice correspond phenotypically and metabolically to humans with hereditary 1,25-dihydroxyvitamin D-resistant rickets (HVDRR). There are no data on the cardiovascular system in human HVDRR. To better understand the effects of vitamin D on the human cardiovascular system, the RAS, blood pressure levels, and cardiac structures were examined in HVDRR patients. Seventeen patients (9 males, 8 females, aged 6 to 36 years) with hereditary HVDRR were enrolled. The control group included age- and gender-matched healthy subjects. Serum calcium, phosphorous, creatinine, 25-hydroxyvitamin D [25(OH)D],1,25-dihydroxyvitamin D(3) [1,25(OH)(2) D(3) ], parathyroid hormone (PTH), plasma rennin activity (PRA), aldosterone, angiotensin II (AT-II), and angiotensin-converting enzyme (ACE) levels were determined. Ambulatory 24-hour blood pressure measurements and echocardiographic examinations were performed. Serum calcium, phosphorus, and alkaline phosphatase values were normal. Serum 1,25(OH)(2) D(3) and PTH but not PRA and ACE levels were elevated in the HVDRR patients. AT-II levels were higher than normal in the HVDRR patients but not significantly different from those of the controls. Aldosterone levels were normal in all HVDRR patients. No HVDRR patient had hypertension or echocardiographic pathology. These findings reveal that 6- to 36-year-old humans with HVDRR have normal renin and ACE activity, mild but nonsignificant elevation of AT-II, normal aldosterone levels, and no hypertension or gross heart abnormalities.

Hypertension and CKD

Hypertension is found in more than 50% of pediatric patients with CKD. However, its prevalence varies according to the cause of CKD. It is relatively infrequent in children with structural disorders. Acquired renal disorders are associated with an increased prevalence of hypertension, similar to that of adults. Recent studies using ambulatory blood pressure monitoring indicate that children with CKD also have a high prevalence of masked hypertension. Similar to adults, long-standing and uncontrolled hypertension in children is associated with the progression of CKD and development of end-organ damage including early cardiomyopathy and premature atherosclerosis. Aggressive treatment of hypertension should be an essential part of pediatric CKD care, not just to prevent the development of symptomatic cardiovascular disease but also to delay progression of CKD. Recent findings from the European Effect of Strict Blood Pressure Control and ACE Inhibition on Progression of Chronic Renal Failure in Pediatric Patients (ESCAPE) trial have shown that the aggressive treatment of blood pressure, to below the 50th percentile, has even greater benefit in children with CKD, unlike results seen in adult studies.