Clinical and research aspects of ambulatory blood pressure monitoring in children

Introducing a Remote Patient Monitoring Usability Impact Model to Overcome Challenges

Telehealth and remote patient monitoring (RPM), in particular, have been through a massive surge of adoption since 2020. This initiative has proven potential for the patient and the healthcare provider in areas such as reductions in the cost of care. While home-use medical devices or wearables have been shown to be beneficial, a literature review illustrates challenges with the data generated, driven by limited device usability. This could lead to inaccurate data when an exam is completed without clinical supervision, with the consequence that incorrect data lead to improper treatment. Upon further analysis of the existing literature, the RPM Usability Impact model is introduced. The goal is to guide researchers and device manufacturers to increase the usability of wearable and home-use medical devices in the future. The importance of this model is highlighted when the user-centered design process is integrated, which is needed to develop these types of devices to provide the proper user experience.

Introducing the Pi-CON Methodology to Overcome Usability Deficits during Remote Patient Monitoring

The adoption of telehealth has soared, and with that the acceptance of Remote Patient Monitoring (RPM) and virtual care. A review of the literature illustrates, however, that poor device usability can impact the generated data when using Patient-Generated Health Data (PGHD) devices, such as wearables or home use medical devices, when used outside a health facility. The Pi-CON methodology is introduced to overcome these challenges and guide the definition of user-friendly and intuitive devices in the future. Pi-CON stands for passive, continuous, and non-contact, and describes the ability to acquire health data, such as vital signs, continuously and passively with limited user interaction and without attaching any sensors to the patient. The paper highlights the advantages of Pi-CON by leveraging various sensors and techniques, such as radar, remote photoplethysmography, and infrared. It illustrates potential concerns and discusses future applications Pi-CON could be used for, including gait and fall monitoring by installing an omnipresent sensor based on the Pi-CON methodology. This would allow automatic data collection once a person is recognized, and could be extended with an integrated gateway so multiple cameras could be installed to enable data feeds to a cloud-based interface, allowing clinicians and family members to monitor patient health status remotely at any time.

Office Blood Pressure Monitoring in Children with Obesity and Obstructive Sleep Apnea

OBJECTIVE

To investigate the relative contributions of obesity and obstructive sleep apnea (OSA) to unfavorable blood pressure in children.

STUDY DESIGN

Children aged 3-18 years with OSA-related symptoms were recruited. All children underwent office blood pressure (BP) monitoring and full-night polysomnography. Obesity was defined as a body mass index ≥95th percentile. OSA severity was divided into primary snoring (apnea-hypopnea index [AHI] <1), mild OSA (5> AHI ≥1), and moderate to severe OSA (AHI ≥5). Age- and sex-adjusted logistic regression analysis was performed to determine the associations among OSA, obesity, and elevated BP.

RESULTS

This cross-sectional study enrolled 1689 children (66% boys), with a mean age of 7.9 years. Compared with children with primary snoring, children with moderate to severe OSA had significantly higher systolic BP (108.1 mmHg vs 105.6 mmHg), diastolic BP (75.0 mmHg vs 70.4 mmHg), systolic BP percentile (75.0 vs 70.4), and diastolic BP percentile (74.0 vs 69.2). The rate of unfavorable BP (ie, elevated BP or hypertension level BP) also was significantly higher in children with more severe OSA. Children with obesity had higher BP and BP percentile. Logistic regression analysis revealed that children with obesity and moderate to severe OSA have a 3-fold greater risk of unfavorable BP compared with children without obesity and primary snoring.

CONCLUSIONS

We identified a 3-fold greater risk of unfavorable BP in children with obesity and moderate to severe OSA.

Pediatric Ambulatory Blood Pressure Classification: The Case for a Change

In 1997, Soergel et al¹ published the first set of normative values for ambulatory blood pressure monitoring (ABPM) in children. Since then, the clinical utility of ABPM has increased dramatically, and now, ABPM is accepted as the standard method to confirm the diagnosis of hypertension in children. Despite significant progress in the field of pediatric ABPM, many important questions remain unanswered. One of the most controversial issues is how to define ambulatory hypertension in children. The purpose of this review is to discuss the limitations of the current pediatric ABPM classification scheme and to provide the justification and rationale for a new classification.

Home Blood Pressure Monitoring as an Alternative to Confirm Diagnoses of Hypertension in Adolescents with Elevated Office Blood Pressure from a Brazilian State Capital

Background

Regional differences of using home blood pressure monitoring (HBPM) as an alternative to ambulatory blood pressure monitoring (ABPM) in hypertensive adolescents are unknown.

Objectives

Define if HBPM is an option to confirm diagnoses of hypertension in adolescents from a Brazilian capital with elevated office blood pressure (BP).

Methods

Adolescents (12-18years) from public and private schools with BP > 90th percentile were studied to compare and evaluate the agreement among office BP measurements, HBPM and ambulatory BP monitoring. Office BP measurements, HBPM and ABPM were performed according to guidelines recommendations. Semi-automatic devices were used for BP measurements. Values of p < 0.05 were considered significant.

Results

We included 133 predominantly males (63.2%) adolescents with a mean age of 15±1.6 years. HBPM systolic blood pressure and diastolic blood pressure mean values were similar to the daytime ABPM values (120.3 ± 12.6 mmHg x 121.5 ± 9.8 mmHg - p = 0.111 and 69.4 ± 7.7 mmHg x 70.2 ± 6.6 mmHg - p = 0.139) and lower than the office measurement values (127.3 ± 13.8 mmHg over 74.4 ± 9.5 mmHg - p < 0,001). The Bland-Altman plots showed good agreement between HBPM and ABPM.

Conclusions

HBPM is an option to confirm diagnoses of hypertension in adolescents from a Brazilian state capital with elevated office BP and can be used as an alternative to ABPM.

Screening for Hypertension in Children and Adolescents: Methodology and Current Practice Recommendations

Hypertension (HTN) requires urgent, uniform, and consistent attention across all frontiers of pediatric health care not only because of established links between the onset of HTN during one's youth and its sustenance throughout adulthood but also because of the sequelae associated with the disease's trajectory, such as cardiovascular disease, end organ damage, and decreased quality of life. Although national guidelines for the diagnosis and management of pediatric HTN have been available for nearly 40 years, knowledge and recognition of the problem by clinicians remain poor due to a host of influencing factors. The purpose of this article is to explicate key issues contributing to the inaccurate measurement of blood pressure and misclassification of HTN among children and to present strategies to address these issues.

Blood pressure (BP) assessment-from BP level to BP variability

The assessment of blood pressure (BP) can be challenging in children, especially in very young individuals, due to their variable body size and lack of cooperation. In the absence of data relating BP with cardiovascular outcomes in children, there is a need to convert absolute BP values (in mmHg) into age-, gender- and height appropriate BP percentiles or Z-scores in order to compare a patient's BP with the BP of healthy children of the same age, but also of children of different ages. Traditionally, the interpretation of BP has been based mainly on the assessment of the BP level obtained by office, home or 24-h BP monitoring. Recent studies suggest that it is not only BP level (i.e. average BP) but also BP variability that is clinically important for the development of target organ damage, including the progression of chronic kidney disease. In this review we describe current methods to evaluate of BP level, outline available methods for BP variability assessment and discuss the clinical consequences of BP variability, including its potential role in the management of hypertension.

The Association of Pediatric Obesity With Nocturnal Non-Dipping on 24-Hour Ambulatory Blood Pressure Monitoring

BACKGROUND

Obesity has been linked with abnormal nocturnal dipping of blood pressure (BP) in adults, which in turn is associated with poor cardiovascular outcomes. There are few data regarding abnormal dipping status in the obese pediatric population. The goal of this study was to further describe the relationship between obesity and non-dipping status on ambulatory blood pressure monitor (ABPM) in children.

METHODS

We conducted a cross-sectional study using a database of patients aged 5-21 years who had undergone 24-hour ABPM at Seattle Children's Hospital from January 2008 through May 2014. Subjects were grouped by body mass index (BMI) into lean (BMI 15th-85th percentile) and obese (BMI >95th percentile) groups.

RESULTS

Compared to lean subjects (n = 161), obese subjects (n = 247) had a prevalence ratio (PR) for non-dipping of 2.15, adjusted for race (95% confidence interval (CI) = 1.25-3.42). Increasing severity of obesity was not further associated with nocturnal non-dipping. Nocturnal non-dipping was not associated with left ventricular hypertrophy (PR = 1.01, 95% CI = 0.71-1.44).

CONCLUSIONS

These results suggest that in children, just as in adults, obesity is related to a relatively decreased dipping in nocturnal BP.

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.

Early Weight Gain, Linear Growth, and Mid-Childhood Blood Pressure: A Prospective Study in Project Viva

In recent years, the prevalence of hypertension and prehypertension increased markedly among children and adolescents, highlighting the importance of identifying determinants of elevated blood pressure early in life. Low birth weight and rapid early childhood weight gain are associated with higher future blood pressure. However, few studies have examined the timing of postnatal weight gain in relation to later blood pressure, and little is known regarding the contribution of linear growth. We studied 957 participants in Project Viva, an ongoing US prebirth cohort. We examined the relations of gains in body mass index z-score and length/height z-score during 4 early life age intervals (birth to 6 months, 6 months to 1 year, 1 to 2 years, and 2 to 3 years) with blood pressure during mid-childhood (6-10 years) and evaluated whether these relations differed by birth size. After accounting for confounders, each additional z-score gain in body mass index during birth to 6 months and 2 to 3 years was associated with 0.81 (0.15, 1.46) and 1.61 (0.33, 2.89) mm Hg higher systolic blood pressure, respectively. Length/height gain was unrelated to mid-childhood blood pressure, and there was no evidence of effect modification by birth size for body mass index or length/height z-score gain. Our findings suggest that more rapid gain in body mass index during the first 6 postnatal months and in the preschool years may lead to higher systolic blood pressure in mid-childhood, regardless of size at birth. Strategies to reduce accrual of excess adiposity during early life may reduce mid-childhood blood pressure, which may also impact adult blood pressure and cardiovascular health.

Nocturnal Hypertension and Attenuated Nocturnal Blood Pressure Dipping is Common in Pediatric Lupus

Hypertension is an important manifestation of systemic lupus erythematosus (SLE) but reports of prevalence vary between 20-70% in published reports of adult and pediatric patients. For both children and adults with SLE, the clinical diagnosis and management of hypertension has traditionally been based on guidelines developed for the general population. In clinical trials, the criteria used for defining participants with hypertension are mostly undefined. As a first step towards formally assessing the blood pressure (BP) patterns of children diagnosed with SLE, 24-hr ambulatory BP monitoring data was analyzed on clinic patients who presented with prehypertension or stage I hypertension. In this pediatric SLE cohort (n=10), 20% met daytime criteria for a diagnosis of hypertension. Patterns of BP elevation varied widely with white coat, masked, isolated systolic, and diastolic nocturnal hypertension all identified. Nocturnal hypertension was detected in 60% and attenuated nocturnal BP dipping in 90% of both hypertensive and normotensive SLE patients. In SLE patients, the median nighttime systolic and diastolic loads were 25% and 15.5% compared with median daily loads of 12.5% and 11.5%. Daytime and nighttime systolic and diastolic BP load and nocturnal dipping was compared to a control population consisting of 85 non-SLE patients under 21 years old with prehypertension or stage 1 hypertension presenting to hypertension clinic. Median systolic BP dipped 5.3 mmHg in SLE patients compared to 11.9 mmHg in non-lupus ( p-value = 0.001). Median diastolic BP dipped 12.9 mmHg versus 18.5 mmHg in non-lupus ( p-value = 0.003). Patterns of BP dysregulation in pediatric SLE merit further exploration. Children with or without SLE displaying prehypertensive or stage 1 casual BP measurements had similar rates of hypertension by ambulatory BP monitoring. However, regardless of BP diagnosis, and independent of kidney involvement, there was an increased proportion with attenuated nocturnal dipping and nocturnal hypertension in SLE patients.

Obstructive sleep apnea and periodic limb movement disorder in a population of children with hypertension and/or nocturnal nondipping blood pressures

There is a reported association between hypertension (HTN) and sleep disorders. The American Academy of Pediatrics recommends screening children with HTN for sleep disorders because sleep disorders increase the risk for cardiovascular disease. We quantified the frequency and severity of sleep disorders within our institution's hypertensive pediatric population and evaluated the effectiveness of performing nocturnal polysomnography (NPSG). In the hypertensive pediatric population referred for NPSG at our institution, 64% were diagnosed with obstructive sleep apnea (OSA) and/or periodic limb movement disorder. Thirty-three percent of those children with HTN had moderate to severe OSA, whereas only 20% of all children evaluated by NPSG had moderate to severe OSA. Those children with HTN were also two times more likely to be diagnosed with periodic limb movement disorder. Screening for sleep disorders and obtaining NPSG in children with HTN increase the identification of comorbid sleep disorders and reduce the risk for cardiovascular disease.

Is Daytime Systolic Load an Important Risk Factor for Target Organ Damage in Pediatric Hypertension?

The aim of this study was to compare ambulatory blood pressure (BP) monitoring (ABPM) data and determine which hypertension type is a risk factor in target organ damage. A total of 82 children (47 boys) with suspected hypertension based on office BP measurements and considered hypertensive by ABPM were studied. Target organ damage included the following: 35.3% hypertensive retinopathy, 25.6% microalbuminuria, 15.8% increased left ventricular mass index, 29.2% increased carotid intima-media thickness (cIMT), 24.3% high augmentation index (AIx), and 19.5% high pulse wave velocity (PWV). The association between BP load, PWV, and cIMT was statistically significant. There were significant correlations between daytime systolic BP load, PWV, AIx, and cIMT. A statistically significant difference was also detected between nighttime systolic BP load, PWV, and cIMT values and nighttime diastolic BP load levels and values of AIx and cIMT. There was also a statistically significant difference between the high level of nighttime diastolic BP load and cIMT. The authors found that target organ damage was seen more often in children with primary hypertension who had systolic loads.

European Society of Hypertension position paper on ambulatory blood pressure monitoring

Ambulatory blood pressure monitoring (ABPM) is being used increasingly in both clinical practice and hypertension research. Although there are many guidelines that emphasize the indications for ABPM, there is no comprehensive guideline dealing with all aspects of the technique. It was agreed at a consensus meeting on ABPM in Milan in 2011 that the 34 attendees should prepare a comprehensive position paper on the scientific evidence for ABPM.This position paper considers the historical background, the advantages and limitations of ABPM, the threshold levels for practice, and the cost-effectiveness of the technique. It examines the need for selecting an appropriate device, the accuracy of devices, the additional information and indices that ABPM devices may provide, and the software requirements.At a practical level, the paper details the requirements for using ABPM in clinical practice, editing considerations, the number of measurements required, and the circumstances, such as obesity and arrhythmias, when particular care needs to be taken when using ABPM.The clinical indications for ABPM, among which white-coat phenomena, masked hypertension, and nocturnal hypertension appear to be prominent, are outlined in detail along with special considerations that apply in certain clinical circumstances, such as childhood, the elderly and pregnancy, and in cardiovascular illness, examples being stroke and chronic renal disease, and the place of home measurement of blood pressure in relation to ABPM is appraised.The role of ABPM in research circumstances, such as pharmacological trials and in the prediction of outcome in epidemiological studies is examined and finally the implementation of ABPM in practice is considered in relation to the issue of reimbursement in different countries, the provision of the technique by primary care practices, hospital clinics and pharmacies, and the growing role of registries of ABPM in many countries.

The impact of malaria in pregnancy on changes in blood pressure in children during their first year of life

We established a maternal birth cohort in Ibadan, Nigeria, where malaria is hyperendemic, to assess how intrauterine exposure to malaria affected infant blood pressure (BP) development. In a local maternity hospital, healthy pregnant women had regular blood films for malaria parasites from booking to delivery. Growth and BP were measured on 318 babies, all followed from birth to 3 and 12 months. Main outcomes were standardized measures of anthropometry and change in BP to 1 year. Babies exposed to maternal malaria were globally smaller at birth, and boys remained smaller at 3 months and 1 year. Change in systolic BP (SBP) during the year was greater in boys than in girls (20.9 versus 15.7 mm Hg; P=0.002) but greater in girls exposed to maternal malaria (18.7 versus 12.7 mm Hg; 95% confidence interval, 1-11 mm Hg; P=0.02). Eleven percent of boys (greater than twice than expected) had a SBP ≥95th percentile (hypertensive, US criteria), of whom 68% had maternal malaria exposure. On regression analysis (β coefficients, mm Hg), sex (boys>girls; β=4.4; 95% confidence interval, 1.1-7.7; P=0.01), maternal malaria exposure (3.64; 0.3-6.9; P=0.03), and weight change (2.4; 0.98-3.8/1 standard deviation score; P=0.001) all independently increased SBP change to 1 year, whereas increase in length decreased SBP (-1.98; -3.6 to -0.40). In conclusion, malaria-exposed boys had excess hypertension, whereas malaria-exposed girls a greater increase in SBP. Intrauterine exposure to malaria had sex-dependent effects on BP, independent of infant growth. Because infant-child-adult BP tracking is powerful, a malarial effect may contribute to the African burden of hypertension.

Pediatric ambulatory blood pressure monitoring: diagnosis of hypertension

Pediatric hypertension (HTN) is a growing concern and should be diagnosed and treated aggressively to reduce the global disease burden. Ambulatory blood pressure monitoring (ABPM) is a useful clinical tool providing a more accurate description of the patient's blood pressure (BP) than office BP measurements, and can be considered the "gold standard" in the evaluation of the pediatric patient with a concern for HTN. The American Heart Association have suggested criteria for diagnosing ambulatory HTN, and research continues into further clarification of how to best utilize the large volume of data obtained from an ABPM report. ABPM has some limitations; however, the advantages far outweigh these. Routine use of ABPM is recommended among clinicians to better evaluate and assess the severity of a child's HTN, and for proper management in order to prevent target organ damage and the resulting sequelae, thereby reducing the burden of cardiovascular risk in hypertensive children and adolescents.

Should mean arterial pressure be included in the definition of ambulatory hypertension in children?

BACKGROUND

The diagnosis of hypertension (HTN)/normotension (NT) on ambulatory blood pressure monitoring (ABPM) is usually based on systolic (SBP) or diastolic blood pressure (DBP). The goal of this study was to analyze whether inclusion of mean arterial pressure (MAP) improves the detection of HTN on ABPM.

METHODS

We retrospectively studied ABPM records in 229 children (116 boys, median age = 15.3 years) who were referred for evaluation of HTN. A diagnosis of HTN was made if: (A) MAP or SBP or DBP was ≥ 1.65 SDS (95th percentile); (B) SBP or DBP was ≥ 1.65 SDS (95th percentile), during 24-h or daytime or night-time in both definitions.

RESULTS

Using definition A, 46/229 patients had HTN compared to definition B by which only 37/229 patients had HTN (p = 0.001). The level of agreement between the two definitions was very good (kappa = 0.86 ± 0.04), however nine patients (19.5 %) were missed by not using MAP in the definition of HTN. These nine patients had only mild HTN with a median Z score of 1.69.

CONCLUSIONS

The inclusion of MAP in the definition of ambulatory HTN significantly increased the number of hypertensive patients. MAP may be very helpful in detecting mild HTN in patients with normal/borderline SBP and DBP.

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.

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.

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.

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.

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.

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.

Importance of ambulatory blood pressure monitoring in adolescent hypertension

There has been a steady increase in the prevalence of adolescent hypertension in recent years. In order to prevent target organ damages, it is important to determine the group of hypertensive adolescents. If repeatedly elevated blood pressure values are observed, with special emphasis on white coat hypertension, which is particularly frequent at this age, ambulatory blood pressure monitoring is highly recommended before pharmacological treatment is started. In addition, performing ambulatory blood pressure monitoring is recommended with target organ damage, resistance to therapy, and suspicion of secondary hypertension. The results of the widely available, simple-to-use device are easy to reproduce.

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.

Role of twenty-four-hour ambulatory blood pressure monitoring in children on dialysis

BACKGROUND AND OBJECTIVES

Pre- or postdialysis BP recordings are imprecise, can be biased, and have poor test-retest reliability in children on dialysis. We aimed to examine the possible differences between pre- and postdialysis BP levels and 24-hour ambulatory BP monitoring (ABPM) in diagnosis of hypertension (HTN).

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Twenty-four children on dialysis had 24-hour ABPM in the interdialytic period, and values were compared with average pre- and postdialysis systolic BP (SBP) and diastolic BP (DBP) recordings that week. Each patient had an echocardiogram to determine presence of left ventricular hypertrophy (LVH).

RESULTS

By ABPM, 8% of patients had white coat HTN and 12% had masked HTN. There was no significant difference in diagnosis of systolic HTN based on ABPM daytime SBP mean or load and postdialysis SBP. However, only 15% of patients had diastolic HTN based on postdialysis measures, whereas 46% of patients had significantly elevated daytime DBP loads and 71% had high nighttime DBP loads on ABPM. Forty-eight percent of patients were SBP nondippers. Children with LVH had higher daytime and nighttime SBP loads, significantly higher daytime and nighttime DBP loads, and lesser degree of nocturnal dipping of SBP compared with those who did not.

CONCLUSION

ABPM is more informative than pre- and postdialysis BPs and improves the predictability of BP as a risk factor for target organ damage. Diagnosis and treatment monitoring of HTN among pediatric dialysis patients is enhanced with addition of ABPM.

Questionnaire survey on pediatric hypertension in Japan and Korea

BACKGROUND

Hypertension (HTN) is no longer viewed as an adult disease. The purpose of the present study was to understand how hypertensive children are evaluated and managed, by surveying pediatricians in Japan and South Korea.

METHODS

A questionnaire was mailed to 109 Japanese (JA) and 159 Korean (KO) pediatric cardiologists, pediatric nephrologists, and other pediatricians.

RESULTS

A total of 127 replies were received (response rate 47%). Most of respondents did not check blood pressure (BP) routinely in outpatient clinics (JA 77%, KO 88%). A mercury sphygmomanometer was the most commonly used method for BP measurements (JA 72%, KO 62%). BP treatment goals were usually set at the 95th percentile for age, gender, and height (JA 47%, KO 54%). More KO used a lower goal in children with primary HTN than JA. KO respondents preferred angiotensin-converting enzyme inhibitors (ACEI) as initial agents regardless of underlying diseases whereas JA respondents chose various medications, that is, calcium channel blockers, diuretics, and ACEI. For BP monitoring, self-monitoring was found to be most frequent in both countries (JA 80%, KO 57%). Ambulatory BP monitoring was not frequently utilized in both countries (JA 33% KO 34%).

CONCLUSION

The current assessment, management and differing trends in pediatric HTN in Japan and Korea have been identified in the present study. Pediatricians should be aware of the growing implications of HTN in children.

Left ventricular geometry in children and adolescents with primary hypertension

BACKGROUND

Children with hypertension (HTN) are at increased risk for left ventricular hypertrophy (LVH). Increased left ventricular (LV) mass (LVM) by the process of remodeling in response to volume or pressure loading may be eccentric (increased LV diameter) or concentric (increased wall thickness). Our objective was to classify LV geometry among children with primary HTN and examine differences in ambulatory blood pressure (ABP).

METHODS

Subjects aged 7-18 years with suspected HTN were enrolled in this cross-sectional study. ABP and LVM index (LVMI) were measured within the same 24-h period. LV geometry was classified as normal, concentric remodeling, concentric LVH, or eccentric LVH.

RESULTS

Children with LVH had significantly higher ambulatory systolic BP (SBP) and diastolic blood pressure (BP) (DBP) levels and body mass index (BMI) Z-score. Sixty-eight children had HTN based upon ABP monitoring (ABPM). Thirty-eight percent of the hypertensive subjects had LVH, with equal distribution in the concentric and eccentric groups. There were significant differences in the 24-h DBP parameters when the eccentric LVH group was compared to the normal geometry and concentric LVH groups. Relative wall thickness (RWT) was inversely associated with night time DBP parameters. These relationships persisted after controlling for BMI Z-score.

CONCLUSIONS

Although the risk for LVH is associated with increased SBP and BMI Z-score, those with eccentric LVH had significantly higher DBP.

Left ventricular geometry in children and adolescents with primary hypertension

BACKGROUND

Children with hypertension (HTN) are at increased risk for left ventricular hypertrophy (LVH). Increased left ventricular (LV) mass (LVM) by the process of remodeling in response to volume or pressure loading may be eccentric (increased LV diameter) or concentric (increased wall thickness). Our objective was to classify LV geometry among children with primary HTN and examine differences in ambulatory blood pressure (ABP).

METHODS

Subjects aged 7-18 years with suspected HTN were enrolled in this cross-sectional study. ABP and LVM index (LVMI) were measured within the same 24-h period. LV geometry was classified as normal, concentric remodeling, concentric LVH, or eccentric LVH.

RESULTS

Children with LVH had significantly higher ambulatory systolic BP (SBP) and diastolic blood pressure (BP) (DBP) levels and body mass index (BMI) Z-score. Sixty-eight children had HTN based upon ABP monitoring (ABPM). Thirty-eight percent of the hypertensive subjects had LVH, with equal distribution in the concentric and eccentric groups. There were significant differences in the 24-h DBP parameters when the eccentric LVH group was compared to the normal geometry and concentric LVH groups. Relative wall thickness (RWT) was inversely associated with night time DBP parameters. These relationships persisted after controlling for BMI Z-score.

CONCLUSIONS

Although the risk for LVH is associated with increased SBP and BMI Z-score, those with eccentric LVH had significantly higher DBP.

[Importance of ambulatory blood pressure monitoring in adolescent hypertension]

The prevalence of adolescent hypertension is increasing. The national epidemiological study found 2.5% prevalence, while it is 4.5% according to the newest international survey. Repeated casual blood pressure measurements, but not ambulatory blood pressure monitoring is needed for the diagnosis of adolescent hypertension on the basis of the presently available European guideline. At the last decade growing evidence came into light for ambulatory blood pressure monitoring in adolescence. These data show better correlation with end-organ damages than casual measurements. In patients with hypertension diagnosed based on repeated casual blood pressure measurements, 24-hour monitoring showed normal blood pressure in 21-47%, so this is the rate of white coat hypertension. Masked hypertension can also be diagnosed with the help of this method, which has a prevalence of 7-11%. We can also get useful data for secondary forms of hypertension. Until the appearance of the new European guidelines, more frequent use of ambulatory blood pressure monitoring is affordable. The confirmation of the diagnosis based on elevated casual blood pressure data is important. Ambulatory blood pressure monitoring is suggested in cases suspicious for white coat or masked hypertension, in cases of target organ damages or therapy resistant hypertension. Before administration of pharmaceutical therapy in adolescence hypertension - according to author's opinion - ambulatory blood pressure monitoring is absolutely necessary.

Arterial HTN in children with T1DM--frequent and not easy to diagnose

INTRODUCTION

To evaluate the diagnostic efficacy of the office blood pressure (OBP) and ambulatory blood pressure monitoring (ABPM) in the assessment of hypertension (HTN) in children with diabetes mellitus type 1 (T1DM).

METHODS

We analyzed OBP and ABPM measurements in 84 diabetic children (43 boys) obtained at a median age of 14.9 yr and 6.3 +/- 3.5 yr after diagnosis of T1DM. OBP and ABPM results were converted into standard deviation scores (SDS). In addition, we analyzed blood pressure loads and nighttime dipping. The comparison between OBP and ABPM was performed using kappa coefficient and receiver operator curve (ROC).

RESULTS

HTN was diagnosed in 43/84 (51%) patients using OBP (>95th percentile), and in 24/84 (29%) patients using ABPM ( > or = 95th percentile during 24 h, day or night). Both methods were in agreement in 33 ABPM normotensive and 16 ABPM hypertensive patients (most had nighttime HTN); 32% patients had white-coat HTN and 9.5% patients had masked HTN. The kappa coefficient was 0.175 (95% CI from -0.034 to 0.384) suggesting poor agreement between OBP and ABPM. Diastolic OBP was a better predictor of ABPM HTN (ROC area under the curve (AUC) = 0.71 +/- 0.06) than systolic OBP (AUC = 0.58 +/- 0.07). The percentage of non-dippers ranged from 7 to 23% in ABPM normotensive patients, and 21-42% in ABPM hypertensive patients who also had significantly higher BP loads (p < 0.0001).

CONCLUSION

Children with T1DM often suffer from nocturnal, white coat- and masked HTN, which can not be assessed and predicted by the OBP.

Comparison of ambulatory blood pressure reference standards in children evaluated for hypertension

OBJECTIVE

The purpose of this study was to systematically compare methods for standardization of blood pressure levels obtained by ambulatory blood pressure monitoring (ABPM) in a group of 111 children studied at our institution.

METHODS

Blood pressure indices, blood pressure loads and standard deviation scores were calculated using the original ABPM and the modified reference standards. Bland-Altman plots and kappa statistics for the level of agreement were generated.

RESULTS

Overall, the agreement between the two methods was excellent; however, approximately 5% of children were classified differently by one as compared with the other method.

CONCLUSION

Depending on which version of the German Working Group's reference standards is used for interpretation of ABPM data, the classification of the individual as having hypertension or normal blood pressure may vary.

Ambulatory blood pressure measurements are related to albumin excretion and are predictive for risk of microalbuminuria in young people with type 1 diabetes

AIMS/HYPOTHESIS

The relationship between BP and microalbuminuria in young people with type 1 diabetes is not completely clear. As microalbuminuria is preceded by a gradual rise in albumin excretion within the normal range, we hypothesised that ambulatory BP (ABP) may be closely related to albumin excretion and progression to microalbuminuria.

METHODS

ABP monitoring (ABPM) was performed in 509 young people with type 1 diabetes (age median [range]: 15.7 [10.7-22.6] years) followed with annual assessments of three early morning urinary albumin:creatinine ratios (ACRs) and HbA(1c). Systolic BP (SBP) and diastolic BP (DBP) and the nocturnal fall in BP were analysed in relation to ACR.

RESULTS

All ABPM variables were significantly related to baseline log(10) ACR (p < 0.001). After the ABPM evaluation, 287 patients were followed for a median of 2.2 (1.0-5.5) years. ABP at baseline was independently related to mean ACR during follow-up. Nineteen initially normoalbuminuric patients developed microalbuminuria after 2.0 (0.2-4.0) years and their baseline daytime DBP was higher than in normoalbuminuric patients (p < 0.001). After adjusting for baseline ACR and HbA(1c), there was an 11% increased risk of microalbuminuria for each 1 mmHg increase in daytime DBP. Forty-eight per cent of patients were non-dippers for SBP and 60% for DBP; however, ACR was not different between dippers and non-dippers and there were no differences in the nocturnal fall in BP between normoalbuminuric and future microalbuminuric patients.

CONCLUSIONS/INTERPRETATION

In this cohort of young people with type 1 diabetes, ABP was significantly related to ACR, and daytime DBP was independently associated with progression to microalbuminuria. Increasing albumin excretion, even in the normal range, may be associated with parallel rises in BP.

Association between blood pressure and carotid intima-media thickness

OBJECTIVE

To investigate the association between blood pressure and carotid intima-media thickness (IMT) in healthy adolescents.

STUDY DESIGN

Study participants included 285 first-year high school students (mean age, 15.2 years) at a rural high school in Korea. Systolic and diastolic blood pressure (SBP and DBP) were measured with an oscillometric automated sphygmomanometer. The carotid arteries were evaluated with high-resolution B-mode ultrasound scanning. IMT value was determined with the average of the maximal IMT at each common carotid artery. Increased IMT was defined as sex-specific top quartile. The odds ratio (OR) for increased IMT per 1 SD increase of SBP and DBP was estimated after adjusting for age, sex, body mass index, waist circumference, fasting glucose level, and total/high-density lipoprotein cholesterol ratio.

RESULTS

Adjusted OR for increased IMT was 1.70 (P = .003) per 12.4 mm Hg SBP and 1.25 (P = .125) per 7.0 mm Hg DBP. When the analyses were performed by sex, increased IMT was associated with both SBP (OR, 2.67; P = .003) and DBP (OR, 1.68; P = .019) in girls, but it was not associated with either SBP (OR, 1.46; P = .093) or DBP (OR, 0.99; P = .972) in boys.

CONCLUSION

These results suggest that higher blood pressure level may be associated with increased carotid IMT in apparently healthy adolescents.

Blood pressure load, proteinuria and renal function in pre-hypertensive children

It is as yet unclear whether blood pressure load (BPL) can affect renal function in pre-hypertensive children. We have studied 250 children, with a mean age of 9.12 +/- 3.28 years, with the aim of assessing if pre-hypertension in children can indeed affect renal function. The study cohort consisted of 146 children with pre-hypertension (group P) and a control group of 104 children with normal blood pressure (group C). All children were tested for orthostatic proteinuria, an exclusion criterion, glomerular filtration rate (GFR), and proteinuria, and ambulatory blood pressure monitoring was performed. Based on the BPL, group P was further subdivided into group P1 (BPL <or= 40%, low BPL) and group P2 (BPL > 40%, high BPL). We found that GFR was reduced in pre-hypertensive children (90.74 +/- 48.69 vs. 110.32 +/- 20.30 ml/min per 1.73 m(2), p < 0.0001) and that proteinuria was increased (145.36 +/- 110.91 vs. 66.84 +/- 42.94 mg/m(2) per 24 h; p < 0.0001). However, mean values were still within normal limits. A comparison of the group with high BPL and that with low BPL revealed that the former had relatively reduced GFR (79.15 +/- 42.04 vs. 96.78 +/- 51.20 ml/min per 1.73 m(2); p < 0.006) and increased proteinuria (198.29 +/- 142.17 vs. 118.31 +/- 80.07 mg/m(2) per 24 h; p < 0.036). In comparison to the reference values of the normal population, the GFR was reduced and proteinuria was increased in the group with high BPL. Based on our results, pre-hypertension in children with high BPL seems to be associated with reduced GFR and increased proteinuria. A reasonable doubt remains that the patients with higher proteinuria and larger reduction of GFR may harbor an as yet unknown subclinical renal condition responsible for the onset of pre-hypertension. Therefore, children with even mildly elevated BP are at risk of developing renal damage and should change their lifestyle to prevent further increases in BP.

Validation of the AM5600 ambulatory blood pressure monitor in children and adolescents

OBJECTIVE

We measured ambulatory blood pressure using the AM5600 in children and adolescents participating in a research study to assess the relationship of blood pressure to risk factors for cardiovascular disease. Although the use of this monitor has been previously reported in adults, it has not been validated in pediatric patients.

PARTICIPANTS AND METHODS

In this study, we assess the accuracy of the monitor as compared with the mercury sphygmomanometer in children of 7-18 years of age.

RESULTS

We found that the mean of the difference between the monitor and the mercury device was 0.29+/-3.5 and 0.045+/-3.7 mmHg for systolic and diastolic blood pressure, respectively, which fulfills the Advancement of Medical Instrumentation standard for use of a device. The cumulative percentage of readings between the two devices which differed by 5, 10 and 15 mmHg or more assigned a grade of A grade to the device according to the British Hypertension Society.

CONCLUSION

The AM5600 ambulatory blood pressure device is valid for measurement of blood pressure in children and adolescents.

Cost-effectiveness of ambulatory blood pressure monitoring in the initial evaluation of hypertension in children

OBJECTIVE

The goal was to determine the cost-effectiveness of ambulatory blood pressure monitoring in the initial evaluation of stage 1 hypertension.

METHODS

Retrospective chart review of data for children referred to Texas Children's Hospital hypertension clinic between January 2005 and August 2006 was performed. We compared the costs of standard evaluations versus the initial use of ambulatory blood pressure monitoring for children with clinic blood pressure measurements suggesting stage 1 hypertension. Charges for clinic visits, laboratory tests, and imaging were obtained from the Texas Children's Hospital billing department.

RESULTS

A total of 267 children were referred. One hundred thirty-nine children did not receive ambulatory blood pressure monitoring; 54 met clinical indications for ambulatory blood pressure monitoring but did not receive it because it was not a covered expense (44 children) or the family refused the study (10 children). One hundred twenty-six children received clinically indicated ambulatory blood pressure monitoring, paid for either through insurance or by the family. Fifty-eight children (46%) had confirmed white-coat hypertension, 62 (49%) stage 1 hypertension, and 6 (5%) stage 2 hypertension. With the observed prevalence of white-coat hypertension, initial ambulatory blood pressure monitoring use yielded net savings after evaluation of 3 patients, with projected savings of $2.4 million per 1000 patients.

CONCLUSIONS

Ambulatory blood pressure monitoring in the initial evaluation of suspected childhood hypertension is highly cost-effective. Awareness of cost saving potential may increase the availability of ambulatory blood pressure monitoring for evaluation of new-onset hypertension.

Serum uric acid and ambulatory blood pressure in children with primary hypertension

Hyperuricemia is associated with primary hypertension (HTN) in adults and children. Furthermore, uric acid levels during childhood are associated with blood pressure (BP) levels in adulthood. We measured 24-h ambulatory BP and serum uric acid (SUA) in 104 children referred for possible hypertension. Mean age was 13.7 +/- 2.6 y (range, 7-18 y) with 67 males and 37 females; 74 were African-American, 29 Caucasian and one Asian. SUA was associated with age (r = 0.38, p = 0.0001) and BMI Z-score (r = 0.23, p = 0.021). SUA was significantly associated with mean ambulatory systolic (S) and diastolic (D) BP. Mean ambulatory BP was normalized to gender- and height-specific reference standards using BP index. SUA was significantly associated with 24-h DBP index and nocturnal DBP index after adjusting for age, gender, race, BMI Z-score and urinary sodium excretion. SUA was also significantly associated with 24-h DBP load and nocturnal DBP load. Uric acid was significantly associated with increased likelihood for diastolic HTN (OR = 2.1, CI = 1.2, 3.7; p = 0.0063) after adjusting for other co-variables. Among children at risk for HTN, the likelihood for diastolic HTN (as defined by ambulatory blood pressure monitoring) increases significantly as SUA increases. SUA may be associated with increased severity of HTN during youth.