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

Does the Body Mass Index Category Influence Ambulatory Blood Pressure Parameters in Office Normotensive Obese Children?

The aim of our study was to investigate the influence of the degree of obesity on ambulatory blood pressure parameters in selected group of office normotensive obese children and adolescents. Our study involved 119 obese patients (55 males, 46.2%) aged 7-18 years divided into 3 groups based on their body mass index Z-score, who underwent ambulatory blood pressure monitoring. Our results show that obese patients, even when office normotensive, have alterations in blood pressure values obtained by ambulatory blood pressure monitoring. We found a positive correlation between systolic and diastolic blood pressure and body mass index in our patients (p [Formula: see text] 0.001). Daytime blood pressure load correlated with rising body mass index and was higher in groups II and III compared to group I (p < 0.001). Body mass index category did not influence the dipping pattern in our subjects although most of our subjects (66.4%) showed non-dipping pattern for systolic blood pressure. The difference in blood pressure variability was confirmed only for daytime systolic and diastolic values between groups I and II (p = 0.019 and p = 0.002, respectively). In conclusion, our study showed that in office normotensive obese children and adolescents, systolic and diastolic blood pressure values obtained by ambulatory blood pressure monitoring are higher in subjects with higher body mass index. Patients with increased body mass index also have higher percentage of blood pressure readings above 95^th percentile and increased daytime blood pressure variability. Obese patients show non-dipping pattern, independently of the rising body mass index category.

Effects of ambulatory blood pressure monitoring parameters on left ventricular mass index in hypertensive children

OBJECTIVE

We aimed to evaluate the effects of blood pressure (BP) values obtained by 24-h ambulatory BP monitoring (ABPM) of hypertensive children and adolescents on left ventricular mass index (LVMI).

METHODS

Patients diagnosed with HT with BP measurements confirmed with ABPM and evaluated with echocardiography for LVMI were included. The patients were divided into two groups according to their BMI as obese and nonobese. SDSs of ABPM parameters were compared between the groups.

RESULTS

A total of 158 children with HT were included in the study. Ninety of these patients were obese. In obese and nonobese cases, mean SDS levels were similar in ABPM parameters, whereas LVMI was significantly higher in obese patients ( P = 0.049). There was a significant correlation between LVMI and 24-h SBP SDS, daytime SBP SDS, 24-h SBP load and daytime BP load. In obese cases, there was a statistically significant correlation between LVMI and 24-h SBP SDS, daytime SBP SDS, 24-h SBP load, daytime SBP load as well as nighttime SBP SDS and nighttime SBP load. When the whole group was evaluated, 24-h SBP SDS was the most effective parameter influencing LVMI ( P = 0.001). Similarly, the most effective ABPM parameter on LVMI in obese patients was 24-h SBP SDS ( P = 0.001).

CONCLUSION

A significantly higher rate of LVMI in obese patients suggests that obesity itself is an effective factor on LVMI. In addition, systolic hypertension is more effective on cardiac functions compared with DBP measurements and systolic-DBP dipping ratios.

Variation in paediatric 24-h ambulatory blood pressure monitoring interpretation by Canadian and UK physicians

Twenty-four-hour ambulatory blood pressure monitoring (ABPM) is widely accepted as a more accurate method for measurement of blood pressure (BP) compared to a single office-based measurement of BP. However, it is unclear how physicians interpret ABPM and make management decisions. This study's goal is to investigate variation in ABPM interpretation among paediatric nephrologists (Canada and UK) and paediatric cardiologists (Canada only) via an online survey. The survey content included baseline demographics, questions on the use and indications for ABPM, interpretation of results, and subsequent management decisions in various clinical scenarios. The survey was sent to 196 Canadian physicians, with 69 (35.2%) total responses. Thirty-five UK clinicians also completed the survey. Most respondents were >44 years old, were in practice for at least 11 years, and were university-based. There were substantial differences among clinicians in ABPM interpretation for isolated systolic, diastolic, and night-time hypertension. For example, only 53.1% of physicians would initiate or modify treatment in those with diastolic HTN in CKD. Further, even for the same abnormal ABPM parameter, the decision to start or alter treatment was influenced by the underlying medical condition. There is significant variation in clinical practice among physicians for interpretation and management of hypertension when using ABPM. Differences in guidelines among various jurisdictions, as well as knowledge gaps in the research on which guidelines are based, create ambiguity regarding ABPM interpretation and management decisions. A more protocolized approach and further insight into the reasoning behind the variation in physicians' interpretation may help to standardise practice.

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.

Practical application of ABPM in the pediatric nephrology clinic

The use of 24-h ABPM has become commonplace when diagnosing and managing hypertension in the pediatric population. Multiple clinical guidelines recommend ABPM as the preferred method for identifying white-coat hypertension, masked hypertension, and determining degree of blood pressure (BP) control. Accurate, timely diagnosis and optimal management are particularly important in certain populations, such as children with chronic kidney disease (CKD), diabetes, and other conditions with increased risk for cardiovascular disease. Understanding how best to utilize ABPM to achieve these goals is important for pediatric nephrologists and other hypertension specialists. This review will provide practical information on the equipment, application, interpretation, and documentation of ABPM in the specialty clinic.

The association between obesity, hypertension and left ventricular mass in adolescents

BACKGROUND

Obesity and hypertension (HT) are well known cardiac risk factors. Our goal was to show that even if arterial blood pressure (BP) measurements of obese adolescents are normal during clinical examination, ambulatory blood pressure monitoring (ABPM) can be high, may include cardiac involvement and can also detect left ventricular mass indices (LVMI) value for obese adolescents to diagnose left ventricular hypertrophy (LVH).

METHODS

This study included 130 children (57 obese hypertensive, 36 obese normotensive, 14 normal weight hypertensive and 23 normal weight normotensive). Adolescents whose BP was measured during clinical examination, after 24-h BP was detected using ABPM, were examined with echocardiography for calculation of LVMI to determine cardiac risk factors for LVH.

RESULTS

There was a significant difference between the LVMI of obese-normotensive and obese-hypertensive adolescents, which showed the effect of obesity on LVMI independent of HT. Twenty (35.7%) of 56 obese adolescents with HT detected with ABPM had normal BP measurements during clinical examination. Dipper and nondipper features of obese adolescents were significantly higher in ABPM than those with normal body mass index. When the cutoff LVMI value for LVH was set at ≥38 g/m2.7, 38.9% of obese-normotensive and 50.9% of obese-hypertensive subjects had LVH; however, when the cutoff value was set at ≥51 g/m2.7, the rates were 2.8% and 19.3%, respectively.

CONCLUSIONS

Obesity is a risk factor for LVH independent of HT. To identify masked HT, 24-h ABPM and cardiac examination should be routinely performed in obese adolescents. Using a limit of LVMI ≥38 g/m2.7 in evaluating LVH secondary to HT in obese individuals may lead to an overestimated diagnosis rate of LVH.

Hypertension in chronic kidney disease: role of ambulatory blood pressure monitoring

Children with chronic kidney disease have a markedly increased risk of cardiovascular morbidity and children with end stage renal disease have an estimated 30 times greater risk of cardiovascular mortality than the general pediatric population. In adults, the link between hypertension and cardiovascular disease is well-documented but that association has not been so readily apparent in children with chronic kidney disease. This may be in part because the early changes in blood pressure that occur in these patients do not necessarily manifest with changes in casual blood pressure measurements. Ambulatory blood pressure monitoring, with its ability to gather multiple readings both during the normal activities of the day and the night, is felt to be a more veritable measure of blood pressure. Its use in children has been hampered by limited data on normative values and difficulties in blood pressure classification, while its use in adults is ever expanding. However, with an increasing number of studies in children with chronic kidney disease, ambulatory blood pressure has revealed a greater prevalence of abnormal findings in this population and has been shown to better predict cardiovascular risk than current standards. Two large multi-center studies in Europe and North America have revealed even greater utility of ambulatory blood pressure measures in this population. It is hoped that continued use of ambulatory monitoring in children will help overcome some of its perceived limitations while also validating its use in those at high risk of cardiovascular morbidity.

Effect of plasma NOx values on cardiac function in obese hypertensive and normotensive pediatric patients

BACKGROUND

Hypertension (HT) is a major comorbidity of obesity that is associated with an increased risk of cardiovascular disease and higher mortality. The aim of our study was to evaluate cardiac function in obese hypertensive (OHT) and obese normotensive (ONT) pediatric patients and determine the effects of plasma nitric oxide (NOx) values on cardiac function, while demonstrating the role of plasma NOx in HT in obese pediatric patients.

METHODS

The study population consisted of 62 patients (27 boys, 35 girls), aged 13-18 years and 21 age-matched healthy controls. All subjects enrolled in the study underwent echocardiography (Echo) evaluation and ambulatory blood pressure monitoring for HT. Plasma NOx and biochemical values were studied in both patient groups separately.

RESULTS

Plasma NOx levels were found to be lower in the OHT group than in the ONT and control groups (p < 0.001) and to be negatively correlated with left ventricular mass index values (p < 0.05). Both the OHT and ONT groups had concentric hypertrophy of the heart.

CONCLUSIONS

Plasma NOx plays an essential role in obesity-induced HT. Concentric hypertrophy of the left ventricle was found in both the OHT and ONT groups, indicating structural deformation of the heart.

Obalon intragastric balloon in the treatment of paediatric obesity: a pilot study

BACKGROUND

Lifestyle interventions are often ineffective in the treatment of pediatric obesity. Weight loss devices have been introduced for the temporary nonsurgical treatment of morbid obesity.

OBJECTIVE

The aim of the study is to evaluate the efficacy of Obalon Intragastric Balloon on weight loss and on metabolic and cardiovascular parameters in a pediatric population with severe obesity.

METHODS

We enrolled 10 children with severe obesity. In all patients anthropometric parameters, biochemical tests, ultrasound liver examination and blood pressure monitoring were evaluated at the time of insertion and after removal of device.

RESULTS

The Obalon had a positive effect on decrease of weight, body mass index and percentage of excess body weight within 3 months from placement. Moreover, this safe minimally invasive device improves the cardio-metabolic profiles of obese children.

CONCLUSIONS

The Obalon could be a useful tool in the difficult management of pediatric patients with morbid obesity, inducing in short-term a meaningful weight loss.

Nighttime Systolic Blood-Pressure Load Is Correlated with Target-Organ Damage Independent of Ambulatory Blood-Pressure Level in Patients with Non-Diabetic Chronic Kidney Disease

Background

The impacts of blood pressure (BP) load on target-organ damage in patients with chronic kidney disease (CKD) are largely unclear. We examined whether BP load is correlated with target-organ damage (TOD) in Chinese CKD patients independent of BP level.

Methods

We recruited 1219 CKD patients admitted to our hospital division in this cross-sectional study. The TOD were measured by estimated glomerular filtration rate (eGFR), proteinuria, left ventricular mass index (LVMI) and carotid intima-media thickness (cIMT) in this study. Univariate and multivariate linear analyses were used to evaluate the relationship between systolic blood pressure (SBP) load, diastolic blood pressure (DBP) load and these renal, cardiovascular parameters.

Results

In multivariable-adjusted models, BP load and ambulatory BP levels both independently correlated with LVMI, eGFR and proteinuria in all groups of CKD patients (p<0.05), 24-h SBP correlated with cIMT only in non-diabetic CKD patients without hypertension (p<0.05), while nighttime SBP load was associated with cIMT only in non-diabetic CKD patients (p<0.05). Furthermore, nighttime SBP load additionally increased coefficient of determination (R²) and correlated with LVMI, proteinuria in non-diabetic CKD patients without hypertension (R² = 0.034, P<0.001 and R² = 0.012, P = 0.006 respectively) and LVMI, cIMT, eGFR in non-diabetic CKD patients with hypertension (R²>0.008, P<0.05) in multivariable-adjusted model which already including the 24-h BP. BP load did not refine this correlation based on the 24-h BP level in diabetic CKD patients.

Conclusion

Night-time SBP load was correlated with TOD in patients with non-diabetic chronic kidney disease independent of BP level.

Left ventricular mass and diastolic function in obese children and adolescents

BACKGROUND

Our aims were to assess left ventricular structure and diastolic function in obese subjects stratified according to ambulatory blood pressure status, and to investigate independent predictors of the left ventricular mass (LVM) index.

METHODS

Obese subjects aged 9-19 years referred for ambulatory blood pressure monitoring (ABPM) were evaluated in the cross-sectional study. In addition to biochemical and anthropometric measurements, subjects underwent ABPM, Doppler echocardiography, and treadmill exercise test.

RESULTS

According to ABPM results, 103 subjects with obesity (mean age 14.1 ± 2 years) were split in two groups: 49 hypertensive, and 54 without hypertension. Left ventricular hypertrophy was found in 16.3 % of hypertensive, and 5.6 % of normotensive. Variables included in stepwise regression analysis as potential determinants of LVM index were age, body mass index z score, waist circumference, peak systolic blood pressure on exercise test, 24-h heart rate, and night heart rate. Peak systolic blood pressure (adjusted R(2) = 0.051, β = 0.245, p = 0.013) remained as the independent predictor of LVM index. Diastolic function evaluated by mitral E/A ratio was decreased in both obese groups.

CONCLUSIONS

Early markers of cardiac disease including hypertrophy and diastolic dysfunction of the left ventricle are present in youths with obesity prior to the development of sustained hypertension.

Subclinical atherosclerosis and ambulatory blood pressure in children with metabolic syndrome

BACKGROUND

The metabolic syndrome (MS) has reached epidemic proportions worldwide. This syndrome is associated with cardiovascular risk factors, including functional and structural cardiac and vascular changes. The aim of our study was to evaluate subclinical atherosclerosis and its associated risk factors in children with MS.

METHODS

The study cohort comprised 52 children with MS and 38 age- and sex-matched healthy children. The diagnosis of MS was made according to criteria adopted by the World Health Organization. Blood pressure based on 24-h ambulatory blood pressure monitoring (ABPM), carotid intima-media thickness (cIMT), carotid distensibility coefficient (DC) and flow-mediated endothelium-dependent dilation (EDD) were assessed in all children.

RESULTS

We found a significantly higher cIMT in children with MS than in healthy children, but carotid DC and flow-mediated EDD were lower in the former. Multivariate analysis revealed that a higher cIMT was independently associated with a higher nighttime systolic blood pressure (SBP) and lower high-density lipoprotein-cholesterol (β = 0.386, p = 0.011 and β = 0.248, p = 0.042, respectively). Also, higher nighttime SBP remained an independent predictor of lower DC (β = 0.495, p = 0.009), and higher 24-h SBP was the only independent predictor for a lower EDD (β = 0.532, p = 0.004).

CONCLUSIONS

Atherosclerotic vascular changes were common among our pediatric patients with MS and easily determined by high-resolution ultrasound imaging. In particular, subclinical atherosclerosis was clearly associated with nocturnal or 24-h systolic hypertension as measured by ABPM. We therefore recommend that subclinical vascular changes and AMBP measurements should be used as diagnostic markers to predict atherosclerotic risks in this pediatric patient group.

Treatment of obesity-related hypertension in children and adolescents

The obesity epidemic has become a common concern among pediatricians, with an estimated 32 % of US children and adolescents classified as overweight and 18 % as obese. Along with the increase in obesity, a growing body of evidence demonstrates that chronic diseases, such as Type 2 diabetes, primary hypertension, and hyperlipidemia, once thought to be confined solely to adulthood, are commonly seen among the obese in childhood. Following a brief summary of the diagnosis and evaluation of hypertension in obese children and adolescents, this review will highlight recent research on the treatment of obesity-related hypertension. Pharmacologic and non-pharmacologic treatment will be discussed. Additionally, current and emerging therapies for the primary treatment of obesity in children and adolescents, which have been gaining in popularity, will be reviewed.