Relationship of ambulatory blood pressure and body mass index to left ventricular mass index in pediatric patients with casual hypertension

Primary and secondary paediatric hypertension

High blood pressure (BP) or hypertension is a well known risk factor for developing heart attack, stroke, atrial fibrillation and renal failure. Although in the past hypertension was supposed to develop at middle age, it is now widely recognized that it begins early during childhood. As such, approximately 5-10% of children and adolescents are hypertensive. Unlike that previously reported, it is now widely accepted that primary hypertension is the most diffuse form of high BP encountered even in paediatric age, while secondary hypertension accounts just for a minority of the cases. There are significant differences between that outlined by the European Society of Hypertension (ESH), the European Society of Cardiology (ESC), and the last statement by the American Academy of Pediatrics (AAP) concerning the BP cut-offs to identify young hypertensive individuals. Not only that, but the AAP have also excluded obese children in the new normative data. This is undoubtedly a matter of concern. Conversely, both the AAP and ESH/ESC agree that medical therapy should be reserved just for nonresponders to measures like weight loss/salt intake reduction/increase in aerobic exercise. Secondary hypertension often occurs in aortic coarctation or chronic renal disease patients. The former can develop hypertension despite early effective repair. This is associated with significant morbidity and is arguably the most important adverse outcome in about 30% of these subjects. Also, syndromic patients, for example those with Williams syndrome, may suffer from a generalized aortopathy, which triggers increased arterial stiffness and hypertension. This review summarizes the state-of-the-art situation regarding primary and secondary paediatric hypertension.

Prevalence of left ventricular hypertrophy in children and young people with primary hypertension: Meta-analysis and meta-regression

BACKGROUND

Left ventricular hypertrophy (LVH) is the main marker of HMOD in children and young people (CYP). We aimed to assess the prevalence of LVH and its determinants in CYP with primary hypertension (PH).

METHODS

A meta-analysis of prevalence was performed. A literature search of articles reporting LVH in CYP with PH was conducted in Medline, Embase, and Cochrane databases. Studies with a primary focus on CYP (up to 21 years) with PH were included. Meta-regression was used to analyze factors explaining observed heterogeneity.

RESULTS

The search yielded a total of 2,200 articles, 153 of those underwent full-text review, and 47 reports were included. The reports evaluated 51 study cohorts including 5,622 individuals, 73% male subjects, and a mean age of 13.6 years. LVH was defined as left ventricle mass index (LVMI) ≥ 95th percentile in 22 (47%), fixed cut-off ≥38.6 g/m2.7 in eight (17%), sex-specific fixed cut-off values in six (13%), and miscellaneously in others. The overall prevalence of LVH was 30.5% (95% CI 27.2-33.9), while heterogeneity was high (I 2 = 84%). Subgroup analysis including 1,393 individuals (76% male subjects, mean age 14.7 years) from pediatric hypertension specialty clinics and LVH defined as LVMI ≥95th percentile only (19 study cohorts from 18 studies), reported prevalence of LVH at 29.9% (95% CI 23.9 to 36.3), and high heterogeneity (I 2 = 84%). Two studies involving patients identified through community screening (n = 1,234) reported lower LVH prevalence (21.5%). In the meta-regression, only body mass index (BMI) z-score was significantly associated with LVH prevalence (estimate 0.23, 95% CI 0.08-0.39, p = 0.004) and accounted for 41% of observed heterogeneity, but not age, male percentage, BMI, or waist circumference z-score. The predominant LVH phenotype was eccentric LVH in patients from specialty clinics (prevalence of 22% in seven studies with 779 participants) and one community screening study reported the predominance of concentric LVH (12%).

CONCLUSION

Left ventricular hypertrophy is evident in at least one-fifth of children and young adults with PH and in nearly a third of those referred to specialty clinics with a predominant eccentric LVH pattern in the latter. Increased BMI is the most significant risk association for LVH in hypertensive youth.

24-Hour ambulatory blood pressure monitoring 7 years after intensive care unit admission

BACKGROUND

Children who develop acute kidney injury (AKI) in the pediatric intensive care unit (PICU) may be at higher risk of long-term chronic kidney disease and hypertension. The objectives of this study were to determine the prevalence of post-discharge hypertension and albuminuria using reference-standard measurements in children admitted to the PICU, and evaluate their association with AKI.

METHODS

Single-center longitudinal cohort study of children admitted to the PICU from 2005 to 2010 with 7-8 years of follow-up (n = 207). Patients were excluded if they had pre-existing chronic kidney disease, were deceased, lived > 3.5-h drive away, were unwilling/unable to provide consent/assent, or had a clotting disorder. AKI was defined by the Kidney Disease: Improving Global Outcomes creatinine definition. Office blood pressure was evaluated using age, sex, and height-based percentiles. Hypertension was defined using 24-h ambulatory blood pressure monitoring (ABPM). Albuminuria was defined as first morning urine albumin:creatinine ratio ≥ 30 mg/g. Prevalence of blood pressure outcomes was calculated. The association between AKI and outcomes was evaluated using multivariable regression.

RESULTS

Sixty of 207 (29%) children developed AKI during PICU admission. Overall, 6% had albuminuria and 21% had elevated office blood pressure or worse. One-hundred-and-seventy-seven (86%) patients had successful ABPM data. Of these, 10 (6%) had white coat, 18 (10%) had masked, and 5 (3%) had ambulatory hypertension. There was no statistically significant difference in outcomes across AKI stages.

CONCLUSIONS

Blood pressure abnormalities are common in children 7 years after PICU admission. Future studies with longer follow-up are needed to further evaluate the association between AKI and hypertension. A higher-resolution version of the graphical abstract is available as Supplementary information.

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.

Effects of blood pressure percentile, body mass index, and race on left ventricular mass in children

OBJECTIVE

To evaluate the association of systolic blood pressure percentile, race, and body mass index with left ventricular hypertrophy on electrocardiogram and echocardiogram to define populations at risk.

STUDY DESIGN

This is a retrospective cross-sectional study design utilising a data analytics tool (Tableau) combining electrocardiogram and echocardiogram databases from 2003 to 2020. Customized queries identified patients aged 2-18 years who had an outpatient electrocardiogram and echocardiogram on the same date with available systolic blood pressure and body measurements. Cases with CHD, cardiomyopathy, or arrhythmia diagnoses were excluded. Echocardiograms with left ventricle mass (indexed to height^2.7) were included. The main outcome was left ventricular hypertrophy on echocardiogram defined as Left ventricle mass index greater than the 95th percentile for age.

RESULTS

In a cohort of 13,539 patients, 6.7% of studies had left ventricular hypertrophy on echocardiogram. Systolic blood pressure percentile >90% has a sensitivity of 35% and specificity of 82% for left ventricular hypertrophy on echocardiogram. Left ventricular hypertrophy on electrocardiogram was a poor predictor of left ventricular hypertrophy on echocardiogram (9% sensitivity and 92% specificity). African American race (OR 1.31, 95% CI = 1.10, 1.56, p = 0.002), systolic blood pressure percentile >95% (OR = 1.60, 95% CI = 1.34, 1.93, p < 0.001), and higher body mass index (OR = 7.22, 95% CI = 6.23, 8.36, p < 0.001) were independently associated with left ventricular hypertrophy on echocardiogram.

CONCLUSIONS

African American race, obesity, and hypertension on outpatient blood pressure measurements are independent risk factors for left ventricular hypertrophy in children. Electrocardiogram has little utility in the screening for left ventricular hypertrophy.

Left Ventricular Measurements and Strain in Pediatric Patients Evaluated for Systemic Hypertension and the Effect of Adequate Anti-hypertensive Treatment

Pediatric hypertension (HTN) is an epidemic that is associated with HTN in adulthood and adverse cardiovascular outcomes. We hypothesized that children with HTN would have left ventricular (LV) hypertrophy and abnormal LV global longitudinal strain (GLS) on echocardiogram and that these values would differ by weight, race, and HTN treatment. Data were collected from first visits to the HTN Program from 12/2011 to 9/2018, excluding patients with cardiac disease or heart transplantation. LV measurements including LV mass index (LVMI), LV GLS, and diastolic indices were compared between groups. Multivariable logistic regression was used to identify risk factors for an abnormal LVMI. There were 212 patients with an interquartile age range of 13-18 years. On univariate analysis, LVMI was higher in hypertensive, obese, and African American patients. LV strain was less negative in obese and African American patients. Adequately treated patients with HTN had a higher LVMI and a higher E/e' ratio compared to patients with no HTN. On multivariate analysis, only obesity was associated with an LVMI ≥ 95th percentile (OR 2.9, 95% CI 1.4, 5.8). LVMI is higher in hypertensive, obese, and African American patients; however, in the multivariate analysis, obesity was the only independent risk factor for an abnormal LVMI. LVMI was still higher in those adequately treated for HTN compared to patients without HTN, possibly due to concomitant obesity. Future studies should focus on subclinical changes in LV performance seen in obese and hypertensive patients and the impact on long-term health.

Electrically induced cycling and nutritional counseling for counteracting obesity after spinal cord injury: A pilot study

Objective: The purpose of this pilot study was to determine the preliminary efficacy of interval functional electrical stimulation (FES) cycling combined with nutritional counseling in obese adults with SCI.Setting: Community-based individuals with chronic SCI.Participants: Ten participants with chronic SCI.Interventions: Participants were divided into 2 groups (1) FES cycling and nutritional counseling (FES & Nutri) and (2) nutritional counseling only (Nutri Only). The FES & Nutri group performed high intensity interval FES cycling for 30 min 3 times per week for 8 weeks and received nutritional counseling for 30 min once per week for 8 weeks. The Nutri Only group received the nutritional counseling only.Outcome Measures: Body composition (fat mass, lean mass, body fat percentage), blood glucose levels.Results: Participants in the FES & Nutri group had a statistically significant greater decrease in body fat percentage (M = -1.14) compared to those in the Nutri Only group (M = +0.28) and gained more lean mass in their legs (M = +0.66 kg) compared to the Nutri Only group (M = -1.05 kg).Discussion/Conclusion: The statistically significant decrease in body fat percentage for the FES & Nutri group provides evidence that further study is merited. Future studies should include larger numbers of participants and the possible introduction of a preliminary strengthening program before initiating interval FES cycling. In addition, an increase in exercise volume and a greater role for nutritional counseling should be considered in order to optimize the treatment for obesity.

Impact of Pediatric Obesity on Diurnal Blood Pressure Assessment and Cardiovascular Risk Markers

Background: The prevalence of hypertension is increasing particularly among obese children and adolescents. Obese children and adolescents with hypertension are likely to remain hypertensive as they reach adulthood and hypertension is linked to an increased risk for cardiovascular disease. Twenty-four-hour ambulatory blood pressure monitoring (ABPM) has become one of the most important tools in diagnosing hypertension in children and adolescents and circadian patterns of blood pressure may be important disease-risk predictors. Methods: A retrospective chart review was conducted in patients aged 6-21 years who underwent 24-h ABPM at Kentucky Children's Hospital (KCH) from August 2012 through June 2017. Exclusion criteria included conditions that could affect blood pressure including chronic kidney disease and other renal abnormalities, congenital heart disease, cancer, and thyroid disease. Subjects were categorized by body mass index into normal (below 85th percentile), overweight (85th-95th percentile), stage I obesity (95th-119th percentile), stage II obesity (120th-139th) and stage III obesity (>140th). Non-dipping was defined as a nocturnal BP reduction of <10%. Results: Two hundred and sixty-three patients (156 male patients) were included in the analysis, of whom 70 were normal weight, 33 overweight, 55 stage I obesity, 53 stage II, and 52 stage III obesity. Although there was no significant difference between normal weight and obese groups for prevalence of hypertension, there was a greater prevalence of SBP non-dipping in obese patients as BMI increased (p = 0.008). Furthermore, non-dippers had a significantly elevated LVMI as well as abnormal lab values for uric acid, blood lipid panel, creatinine, and TSH (p < 0.05). Conclusions: These findings demonstrate that obese children and adolescents constitute a large proportion of hypertensive children and adolescents and the severity of pediatric obesity is associated with nocturnal BP non-dipping. Additionally, obesity in children is linked to several cardiovascular risk factors including left ventricular hypertrophy, dyslipidemia, and elevated uric acid levels. Further studies utilizing ABPM measures on risk stratification in this very high-risk population are warranted.

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

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

Ambulatory systolic blood pressure and obesity are independently associated with left ventricular hypertrophic remodeling in children

BACKGROUND

Children with obesity have hypertrophic cardiac remodeling. Hypertension is common in pediatric obesity, and may independently contribute to hypertrophy. We hypothesized that both the degree of obesity and ambulatory blood pressure (ABP) would independently associate with measures of hypertrophic cardiac remodeling in children.

METHODS

Children, aged 8-17 years, prospectively underwent cardiovascular magnetic resonance (CMR) and ABP monitoring. Left ventricular (LV) mass indexed to height2.7 (LVMI), myocardial thickness and end-diastolic volume were quantified from a 3D LV model reconstructed from cine balanced steady state free precession images. Categories of remodeling were determined based on cutoff values for LVMI and mass/volume. Principal component analysis was used to define a "hypertrophy score" to study the continuous relationship between concentric hypertrophy and ABP.

RESULTS

Seventy-two children were recruited, and 68 of those (37 healthy weight and 31 obese/overweight) completed both CMR and ABP monitoring. Obese/overweight children had increased LVMI (27 ± 4 vs 22 ± 3 g/m2.7, p < 0.001), myocardial thickness (5.6 ± 0.9 vs 4.9 ± 0.7 mm, p < 0.001), mass/volume (0.69 ± 0.1 vs 0.61 ± 0.06, p < 0.001), and hypertrophy score (1.1 ± 2.2 vs -0.96 ± 1.1, p < 0.001). Thirty-five percent of obese/overweight children had concentric hypertrophy. Ambulatory hypertension was observed in 26% of the obese/overweight children and none of the controls while masked hypertension was observed in 32% of the obese/overweight children and 16% of the controls. Univariate linear regression showed that BMI z-score, systolic BP (24 h, day and night), and systolic load correlated with LVMI, thickness, mass/volume and hypertrophy score, while 24 h and nighttime diastolic BP and load also correlated with thickness and mass/volume. Multivariate analysis showed body mass index z-score and systolic blood pressure were both independently associated with left ventricular mass index (β=0.54 [p < 0.001] and 0.22 [p = 0.03]), thickness (β=0.34 [p < 0.001] and 0.26 [p = 0.001]) and hypertrophy score (β=0.47 and 0.36, both p < 0.001).

CONCLUSIONS

In children, both the degree of obesity and ambulatory blood pressures are independently associated with measures of cardiac hypertrophic remodeling, however the correlations were generally stronger for the degree of obesity. This suggests that interventions targeted at weight loss or obesity-associated co-morbidities including hypertension may be effective in reversing or preventing cardiac remodeling in obese children.

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.