Blood Pressure and Body Weight Have Different Effects on Pulse Wave Velocity and Cardiac Mass in Children

Cardiac Structure and Function in 8- to 12-Year-Old Children Following In-Utero Exposure to Preeclampsia (FINNCARE Study)

BACKGROUND

We evaluated how elevated blood pressure in children exposed to preeclampsia (PE) impacted on their cardiac structure and function, as well as relations with maternal, gestational, and perinatal factors and child body size and composition.

METHODS AND RESULTS

A total of 182 PE (46 early-onset preeclampsia) and 85 unexposed (non-PE) children were examined in the FINNCARE study 8 to 12 years after the index pregnancy with echocardiography; office, central, and 24-hour ambulatory blood pressures; and body anthropometrics and composition. PE children had lower right ventricular basal sphericity index (mean difference, -0.26 95% CI, -0.39 to -0.12) and lower mitral lateral E'-wave peak velocity (-1.4 cm/s [95% CI, -2.1 to -0.6]), as well as higher E to E' ratio (0.40 [95% CI, 0.15-0.65]) and indexed tricuspid annular plane systolic excursion (0.03 [95% CI, 0.01-0.05]) compared with non-PE children. These differences were accentuated in early-onset PE children. Left ventricular mass (LVM) or left atrial volume were not different between PE and non-PE children. Lean body mass, body fat percentage, and 24-hour systolic blood pressure were independent predictors of LVM. Lean body mass and body fat percentage were independent predictors of left atrial volume. No significant associations between LVM or left atrial volume and maternal, gestational, or perinatal parameters were found.

CONCLUSIONS

Preadolescent PE children display a more globular-shaped right ventricle with higher longitudinal systolic displacement as well as mildly altered diastolic indices, with the alterations being pronounced in early-onset preeclampsia. Lean body mass and adiposity are independently related with LVM and left atrial volume, and systolic blood pressure with LVM in both PE and non-PE children. These unfavorable associations indicate remodeling of cardiac structure in young children also reflected in mild functional changes in PE children.

REGISTRATION

URL: https://www.clinicaltrials.gov; unique identifier: NCT04676295.

Non-Pharmacological Treatment for Cardiovascular Risk Prevention in Children and Adolescents with Obesity

In younger generations, excess weight has reached very alarming levels. Excess weight in adults is associated with increased mortality and morbidity from cardiovascular disease. However, it is not easy to distinguish to what extent these effects are the result of obesity itself or how much is due to the various cardiovascular risk factors that often accompany excess weight. Several risk factors, such as hypertension, dyslipidemia, hyperuricemia, glucose intolerance, and type 2 diabetes mellitus, are already present in pediatric age. Therefore, early intervention with the goal of correcting and/or eliminating them is particularly important. In the child and adolescent with obesity, the first approach to achieve weight reduction and correct the risk factors associated with severe excess weight should always be non-pharmacologic and based on changing poor eating habits and unhealthy lifestyles. The purpose of this review is to give an update on non-pharmacological interventions to be implemented for cardiovascular prevention in children and adolescents with obesity, and their effectiveness. In particular, interventions targeting each individual cardiovascular risk factor will be discussed.

Body Mass Index (BMI) Is the Strongest Predictor of Systemic Hypertension and Cardiac Mass in a Cohort of Children

BACKGROUND

Hypertension (HTN) is a well-established cardiovascular (CV) risk factor in adults. The presence of HTN in children appears to predict its persistence into adulthood. Early diagnosis of HTN is crucial to reduce CV morbidity before the onset of organ damage.

AIM

The aim of this study is to investigate cardiac damage in HTN, its risk factors (RFs), and evolution.

METHODS

We conducted a prospective/retrospective study involving children referred to the Childhood Hypertension Outpatient Clinic. This study included clinical and echocardiographic assessments of cardiac morphology and function at three time points: enrollment (T0) and follow-up (T1 and T2).

RESULTS

Ninety-two patients (mean age 11.4 ± 3 years) were enrolled. Cardiac eccentric and concentric hypertrophy were present in 17.9% and 9%, respectively, with remodeling in 10.5%. Overweight/obese subjects exhibited significantly higher systolic blood pressure (SBP), frequency of HTN, and body mass index (BMI) at T0 compared with patients with chronic kidney disease (CKD). SBP and BMI persisted more during follow-up. Normal-weight vs. overweight/obese patients were significantly more likely to have normal geometry. Positive correlations were found between BMI and left ventricular (LV) mass at T0, BMI and SBP at T0 and T1. Gender, BMI, SBP, and diastolic blood pressure (DBP) significantly predicted LV mass index (LVMI), but only BMI added significance to the prediction. During follow-up, the variation of BMI positively correlated with the variation of SBP, but not with LVMI.

CONCLUSIONS

In our cohort, body weight is strongly associated with HTN and cardiac mass. Importantly, the variation in body weight has a more significant impact on the consensual variation of cardiac mass than blood pressure (BP) values. A strict intervention on weight control through diet and a healthy lifestyle from early ages might reduce the burden of CV morbidity in later years.

Wall Properties of Elastic and Muscular Arteries in Children and Adolescents at Increased Cardiovascular Risk

BACKGROUND

Pulse wave velocity (PWV) assessment represents a simple method to estimate arterial distensibility. At present, carotid-femoral PWV (cf-PWV) is considered the gold standard method in the non-invasive evaluation of the elastic properties of the aorta. On the other hand, the mechanical properties of muscular arteries can be evaluated on the axillo-brachial-radia axis by estimating the carotid-radial PWV (cr-PWV). While a number of studies have addressed these issues in adults, limited information is available on the respective features of cf-PWV and cr-PWV and on their modulating factors in children and adolescents at increased cardiovascular risk.

METHODS

The mechanical properties of the predominantly elastic (aorta) and muscular (axillo-brachial-radial axis) arteries were evaluated in a pediatric population characterized by either elevated blood pressure (BP) or excess body weight, and the main factors affecting cf-PWV and cr-PWV values in these individuals were investigated.

RESULTS

443 children and adolescents (median age 11.5 years, 43.3% females) were enrolled; 25% had BP values >90th percentile and 81% were excess weight. The cf-PWV values were significantly lower than the cr-PWV values: median (Q1-Q3) = 4.8 m/s (4.3-5.5) and 5.8 m/s (5.0-6.5), respectively (p < 0.001). The pubertal development (p < 0.03), systolic BP and diastolic BP z-scores (p = 0.002), heart rate (p < 0.001), and waist-to-height ratio (p < 0.005) were significantly associated with cf-PWV values. No significant association was found between BMI z-score and cf-PWV. Predictors of high cf-PWV (>95th percentile) were the heart rate (OR 1.07, 95%CI 1.04-1.10, p < 0.001) and waist-to-height ratio (OR 1.06, 95%CI 1.0-1.13, p = 0.04). The variables significantly related with cr-PWV values were diastolic BP z-score (p = 0.001), heart rate (p < 0.01), and HOMA index (p < 0.02). No significant association was found between the cr-PWV and BMI z-score or waist-to-height ratio.

CONCLUSIONS

Systolic and diastolic BP values and central obesity are associated with aortic stiffness in a population of children and adolescents at increased cardiovascular risk. In contrast, diastolic BP, heart rate, and levels of insulin resistance appear to be related to distensibility of the upper limb vascular district.

Different Associations of Systolic Blood Pressure and Body Mass Index With Cardiac Structure and Function in Young Children

Background:

Both elevated systolic blood pressure (SBP) and excess weight can lead to early cardiovascular organ damage in children. In this study, we investigated whether there is a difference in the associations of SBP and body mass index (BMI) with cardiovascular structure and function in 4-year-old children.

Methods:

In 1474 children (52.3% males) from the Shanghai Birth Cohort, physical examination and echocardiography were performed. Standardized linear regression models were used to evaluate the associations of BMI Z score and SBP Z score with cardiovascular parameters and to compare the strengths of these associations.

Results:

The incidence of SBP elevation significantly increased in overweight children. SBP was positively related to heart rate, left ventricular (LV) ejection fraction and fraction shortening (β=1.824 [95% CI, 1.014–2.634], 0.579 [0.294–0.864], and 0.480 [0.257–0.704], respectively). BMI Z score was positively associated with LV mass index (β=1.225 [0.863–1.587]) and the risk of LV hypertrophy (odds ratio=1.428 [1.157–1.761]) but negatively related to measures of systolic function, including LV ejection fraction, LV fraction short, and global longitudinal strain (β=−0.417 [−0.735 to −0.099], −0.302 [−0.551 to −0.053], and −0.392 [−0.621 to −0.163], respectively). No noteworthy additive or multiplicative interactions between BMI and SBP were detected.

Conclusions:

Elevations in both BMI and SBP were related to cardiac structure and function in children as young as 4 years old. Elevated SBP was associated with increased heart rate and LV ejection at the early stage of BP elevation. BMI showed a closer relationship with left heart diameters and geometry than SBP.

A Systematic Review of the Associations of Adiposity and Cardiorespiratory Fitness With Arterial Structure and Function in Nonclinical Children and Adolescents

PURPOSE

To summarize the evidence on associations of adiposity and cardiorespiratory fitness (CRF) with arterial structure and function in nonclinical children and adolescents.

METHODS

Two researchers conducted a search in 5 electronic databases in April 2022 to find studies in nonclinical youth (age 5-17.9 y) reporting multivariable associations. Studies were eligible if adiposity and/or CRF were used as the predictor and arterial structure and/or function was the outcome. The Quality Assessment Tool for Quantitative Studies was used to assess methodological quality for experimental studies, and a modified version was used for observational studies.

RESULTS

Ninety-nine studies (72.7% cross-sectional) were included. Ninety-four assessed associations between adiposity and arterial outcomes, most using overall body proportion (n = 71), abdominal (n = 52), or whole-body adiposity (n = 40). Most evidence was inconsistent or nonsignificant, but 59 studies suggested higher abdominal adiposity and worse body proportion were associated with adverse arterial outcomes. Twenty-one assessed associations between CRF and arterial outcomes, with findings inconsistent. Most evidence was rated weak in quality.

CONCLUSION

While high adiposity may contribute to poor arterial outcomes, evidence is limited regarding CRF. Future studies should disentangle these associations by studying youth with healthy adiposity but poor CRF, or vice versa, using longitudinal or experimental study designs.

Uric acid and arterial stiffness in children and adolescents: Role of insulin resistance and blood pressure

Several studies describe the association between serum uric acid (SUA) and arterial stiffness in adults. Uric acid contributes through several mechanisms to the increase in blood pressure (BP) and adversely affects the insulin signaling pathway. Moreover, SUA predict the development of hypertension and insulin resistance up to type 2 diabetes. Early arterial stiffening, estimated by carotid-femoral pulse wave velocity (PWV), may already be present in pediatric age. Aim of our study was to investigate the relationship between SUA and PWV in a pediatric population and its interaction with insulin resistance and BP. In 322 children and adolescents (56.2% male, mean age 11.3 [SD 2.8] years), we measured weight, height, waist circumference, BP and PWV. We also assayed SUA and estimated glomerular filtration rate (eGFR) and calculated HOMA-index as a marker of insulin resistance. Simple and multiple regression analyses were performed to assess variables associated with PWV. Mediation models were applied to identify the direct and indirect effects of individual variables on PWV. On univariate analysis, age (p < 0.001), waist circumference-to-height ratio (p = 0.036), systolic and diastolic BP (SBP and DBP) z-score (p < 0.001), heart rate (p = 0.028), SUA (p = 0.002), HOMA-index (p < 0.001), and eGFR (p = 0.014) were significantly associated with PWV. The multiple regression model showed that only age (p = 0.028), SBP z-score (p = 0.006), and heart rate (p = 0.001) were significantly associated with PWV. The results were superimposable when the DBP z-score replaced the SBP z-score in the model. Mediation models showed that the effect of eGFR on PWV was fully mediated by SUA (p = 0.015) and that the effect of SUA on PWV was totally mediated by HOMA-index (p < 0.001). Both SUA (p < 0.01) and HOMA-index (p < 0.01) had a significant association with higher SBP (DBP) z-scores. The double mediation model including both BP and HOMA-index showed that the SUA effect on PWV was totally mediated by both variables (p = 0.005, for HOMA-index, p = 0.004, for SBP z-score and p = 0.007, for combined effect). The results were superimposable when the DBP z-score replaced the SBP z-score in the model. In conclusion, insulin resistance and BP are both important mediators of the association between SUA and vascular stiffness in pediatric age.

Differential Roles of Life-Course Cumulative Burden of Cardiovascular Risk Factors in Arterial Stiffness and Thickness

BACKGROUND

Data are limited regarding differential and common effects of cardiovascular risk factors on subclinical changes in vascular structure and function. We aimed to examine the relationships of life-course cumulative burdens of cardiovascular risk factors with adult arterial pulse wave velocity (PWV) and carotid intima-media thickness (CIMT) in a longitudinal cohort of the Bogalusa Heart Study.

METHODS

The cohort consisted of 900 subjects who had aortic-femoral PWV and CIMT measurements. These participants were examined 5-16 times for body mass index (BMI), blood pressure, atherogenic index of plasma (AIP), and low-density lipoprotein cholesterol (LDLC) from childhood to adulthood. The area under the curve (AUC) was calculated as a measure of long-term burden of the risk factors.

RESULTS

Adjusting for covariates, adult PWV was associated with AUCs of BMI, systolic blood pressure (SBP) and AIP (standardized regression coefficient [β] = 0.191, 0.321, 0.153, respectively; P < 0.001 for all). Adult CIMT was associated with AUCs of BMI, SBP, AIP and LDLC (β = 0.115, 0.202, 0.141, 0.152, respectively; P < 0.001 for all). Moreover, childhood BMI was associated with adult PWV and CIMT (β = 0.088 and 0.075, respectively; false discovery rate q values < 0.05 for both), and childhood LDLC with adult CIMT (β = 0.079; false discovery rate q value < 0.05). These associations did not differ significantly among race and sex groups.

CONCLUSIONS

The life-course cumulative burden of BMI, SBP, and AIP has common effects on arterial wall stiffening and thickening, whereas LDLC is specifically associated with arterial wall thickness, and this effect starts in early life.

Cystamine reduces vascular stiffness in Western diet-fed female mice

Consumption of diets high in fat, sugar, and salt (Western diet, WD) is associated with accelerated arterial stiffening, a major independent risk factor for cardiovascular disease (CVD). Women with obesity are more prone to develop arterial stiffening leading to more frequent and severe CVD compared with men. As tissue transglutaminase (TG2) has been implicated in vascular stiffening, our goal herein was to determine the efficacy of cystamine, a nonspecific TG2 inhibitor, at reducing vascular stiffness in female mice chronically fed a WD. Three experimental groups of female mice were created. One was fed regular chow diet (CD) for 43 wk starting at 4 wk of age. The second was fed a WD for the same 43 wk, whereas a third cohort was fed WD, but also received cystamine (216 mg/kg/day) in the drinking water during the last 8 wk on the diet (WD + C). All vascular stiffness parameters assessed, including aortic pulse wave velocity and the incremental modulus of elasticity of isolated femoral and mesenteric arteries, were significantly increased in WD- versus CD-fed mice, and reduced in WD + C versus WD-fed mice. These changes coincided with respectively augmented and diminished vascular wall collagen and F-actin content, with no associated effect in blood pressure. In cultured human vascular smooth muscle cells, cystamine reduced TG2 activity, F-actin:G-actin ratio, collagen compaction capacity, and cellular stiffness. We conclude that cystamine treatment represents an effective approach to reduce vascular stiffness in female mice in the setting of WD consumption, likely because of its TG2 inhibitory capacity.NEW & NOTEWORTHY This study evaluates the novel role of transglutaminase 2 (TG2) inhibition to directly treat vascular stiffness. Our data demonstrate that cystamine, a nonspecific TG2 inhibitor, improves vascular stiffness induced by a diet rich in fat, fructose, and salt. This research suggests that TG2 inhibition might bear therapeutic potential to reduce the disproportionate burden of cardiovascular disease in females in conditions of chronic overnutrition.

Association of obesity phenotypes with left ventricular mass index and left ventricular hypertrophy in children and adolescents

It has been argued that metabolically healthy obesity (MHO) does not increase the risk of cardiovascular disease. The aim of this study is to evaluate whether, in a population of obese children/adolescents, the metabolically unhealthy obesity (MUO) phenotype is associated with higher left ventricular mass index and/or higher prevalence of left ventricular hypertrophy than the MHO phenotype. We also tested whether the addition of an insulin resistance index (HOMA-index >90th percentile by sex and age) and the presence of hyperuricemia (serum uric acid >90th percentile by sex and age) to the definition of MUO better identified obese children with early cardiac damage. Left ventricular hypertrophy was defined as the presence of left ventricular mass index greater than or equal to the age- and sex-specific 95th percentile. The study population included 459 obese children (males 53.2%, mean age 10.6 [standard deviation, 2.6] years), of whom 268 (58.4%) were MUO. The left ventricular mass index was higher in MUO children than in MHO children (37.8 vs 36.3 g/m^2.7, p=0.015), whereas the percentage of MUO children presenting left ventricular hypertrophy was only slightly higher in MUO children (31.1 vs 40%, p=0.06). Multiple linear regression analyses showed that the variables significantly associated with higher left ventricular mass index were male gender (p<0.01), Body Mass Index z-score (p<0.001) and Waist-to-Height-ratio (p<0.001). Multiple logistic regression analyses showed that the presence of left ventricular hypertrophy was only significantly associated with higher Body Mass Index z-score (p<0.05) and Waist-to-Height-ratio (p<0.05). In spite of the higher left ventricular mass index of MUO as compared to MHO children, the MUO phenotype was not a significant predictor of either higher left ventricular mass index or higher left ventricular hypertrophy prevalence. The MUO phenotype had a low predictive ability on the presence of left ventricular hypertrophy. The area under the receiver operating characteristic curve was 0.57 (sensitivity 0.64, 1-specificity 0.55). The addition of insulin resistance and hyperuricemia to the definition of MUO did not change the results observed with the standard definition of MUO at multivariable analysis. The MUO phenotype appears to be of little usefulness in identifying the early presence of cardiac damage in a large population of obese children and adolescents. Excess weight and abdominal obesity are confirmed as an important determinant of early organ damage in obese children.