Haemodynamics of Hypertension in Children

Arterial stiffness indices, pulse wave velocity and central systolic blood pressure, are able to discriminate between obese and non-obese children

The objectives of this study were to verify, first, if arterial stiffness indices can discriminate between obese and healthy children. Second, to evaluate arterial stiffness index predictors and hemodynamic parameters in obese children. Arterial stiffness indices evaluated were pulse wave velocity (PWV), central systolic blood pressure (SBPc), and central pulse pressure (PPc). A cross-sectional, descriptive, comparative study design was used. The sample consisted of 78 normal-weight children (8.1 ± 1.96 years) and 58 obese children (9.0 ± 1.87 years). PWV, PPc, and SBPc were significantly higher in the group of obese children than in the control group. The ROC curve analysis showed that maximum PWV and SBPc sensitivity and specificity in differentiating obese from non-obese children occurred at 4.09 m/s and 86.17 mmHg, respectively. PPc did not exhibit a discriminatory capacity between the two groups. Peripheral systolic blood pressure (SBPp), peripheral pulse pressure (PPp), and PPc (R² = 0.98) were predictors of increased PWV. Augmentation pressure, PPp, and reflection coefficient (R² = 0.873) were predictors of PPc. Age, augmentation index, total vascular resistance, cardiac index, and mean fat percentage (R² = 0.801) were predictors of SBPc.

CONCLUSION

This study shows for the first time that PWV > 4.09 m/s and SBPc > 86.17 mmHg are cut-off points associated with a higher risk of obesity. These results indicate that the simple, rapid, and noninvasive measurement of arterial stiffness adds prognostic information regarding cardiovascular risk, in addition to increased body mass index.

WHAT IS KNOWN

• Overweight and obesity are strongly associated with comorbidities que contribute to the development of cardiovascular diseases.

WHAT IS NEW

• This is the first study to show that PWV and SBPc can discriminate obese from non-obese children. These results show that, in addition to an increased BMI, a simple, rapid, and noninvasive measurement of arterial stiffness adds prognostic information on cardiovascular risk.

Hypertension in Children and Young Adults

Primary hypertension (PH) is most common during adolescence with increasing prevalence globally, alongside the epidemic of obesity. Unlike in adults, there are no data on children with uncontrolled hypertension and their future risk of hard cardiovascular and cerebrovascular outcomes. However, hypertension in childhood is linked to hypertensive-mediated organ damage (HMOD) which is often reversible if treated appropriately. Despite differing guidelines regarding the threshold for defining hypertension, there is consensus that early recognition and prompt management with lifestyle modification escalating to antihypertensive medication is required to ameliorate adverse outcomes. Unfortunately, many unknowns remain regarding pathophysiology and optimum treatment of childhood hypertension.

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.

Comparisons of tri-ponderal mass index and body mass index in discriminating hypertension at three separate visits in adolescents: A retrospective cohort study

OBJECTIVE

To estimate whether the new obesity indicator tri-ponderal mass index (TMI) has a better capacity to predict adolescent hypertension (HTN) and HTN subtypes at three separate blood pressure (BP) visits than the conventionally used body mass index (BMI).

METHODS

A total of 36,950 adolescents who had initial normal BP from 2012 to 2019 were included in Suzhou, China. HTN was defined as having three separate visits of elevated BP in 2020. The area under the receiver-operating characteristic curve (AUC), false-positive rate, false-negative rate, total misclassification rates, net reclassification improvement (NRI), and integrated discrimination improvement were calculated to compare the discriminative ability of HTN between BMI and TMI.

RESULTS

TMI had better predictive abilities than BMI among all of the participants when predicting HTN (difference in AUC = 0.019, 95% CI = 0.007-0.031; NRI = 0.067, 95% CI = 0.008-0.127) and isolated systolic hypertension (difference in AUC = 0.021, 95% CI = 0.005-0.036; NRI = 0.106, 95% CI = 0.029-0.183). The difference in prediction abilities between BMI and TMI was more obvious in the subgroup of age ≥16. Also, TMI outperformed BMI in predicting adolescent HTN in girls but not in boys.

CONCLUSION

Compared with BMI, TMI may have a better predictive capacity for HTN, particularly in girls and older adolescents. TMI has the potential to be used as an effective predictor for HTN in clinic practice. Further studies are needed to verify the utility of TMI.

Objective Home-Monitoring of Physical Activity, Cardiovascular Parameters, and Sleep in Pediatric Obesity

<b><i>Introduction:</i></b> Clinical research and treatment of childhood obesity is challenging, and objective biomarkers obtained in a home-setting are needed. The aim of this study was to determine the potential of novel digital endpoints gathered by a home-monitoring platform in pediatric obesity. <b><i>Methods:</i></b> In this prospective observational study, 28 children with obesity aged 6–16 years were included and monitored for 28 days. Patients wore a smartwatch, which measured physical activity (PA), heart rate (HR), and sleep. Furthermore, daily blood pressure (BP) measurements were performed. Data from 128 healthy children were utilized for comparison. Differences between patients and controls were assessed via linear mixed effect models. <b><i>Results:</i></b> Data from 28 patients (average age 11.6 years, 46% male, average body mass index 30.9) and 128 controls (average age 11.1 years, 46% male, average body mass index 18.0) were analyzed. Patients were recruited between November 2018 and February 2020. For patients, the median compliance for the measurements ranged from 55% to 100% and the highest median compliance was observed for the smartwatch-related measurements (81–100%). Patients had a lower daily PA level (4,597 steps vs. 6,081 steps, 95% confidence interval [CI] 862–2,108) and peak PA level (1,115 steps vs. 1,392 steps, 95% CI 136–417), a higher nighttime HR (81 bpm vs. 71 bpm, 95% CI 6.3–12.3) and daytime HR (98 bpm vs. 88 bpm, 95% CI 7.6–12.6), a higher systolic BP (115 mm Hg vs. 104 mm Hg, 95% CI 8.1–14.5) and diastolic BP (76 mm Hg vs. 65 mm Hg, 95% CI 8.7–12.7), and a shorter sleep duration (difference 0.5 h, 95% CI 0.2–0.7) compared to controls. <b><i>Conclusion:</i></b> Remote monitoring via wearables in pediatric obesity has the potential to objectively measure the disease burden in the home-setting. The novel endpoints demonstrate significant differences in PA level, HR, BP, and sleep duration between patients and controls. Future studies are needed to determine the capacity of the novel digital endpoints to detect effect of interventions.

A demographic approach to assess elevated blood pressure and obesity in prepubescent children: the ExAMIN Youth South Africa study

BACKGROUND

Obesity and hypertension prevalence among children are a concern, with limited evidence available on sex and ethnic differences in childhood blood pressure. We aimed to determine the number of children with hypertension and obesity to identify unique adiposity and blood pressure characteristics by sex and ethnicity, and to estimate the odds of having elevated blood pressure with increasing adiposity.

METHODS

We included 1062 healthy children (5-9 years of age) in an observational school-based study in South Africa. Pediatric validated automated devices were used to measure brachial blood pressure and performed pulse wave analysis to assess central hemodynamics. Standard anthropometry was carried out to determine body composition and demographic questionnaires were completed.

RESULTS

Almost 20% of children were overweight/obese and 14.1% had elevated blood pressure or hypertension (22.8%). Ethnic differences included greater adiposity in white compared with black children (all P < 0.0001), but higher DBP and total vascular resistance in black compared with white children (both P < 0.05). DBP and total vascular resistance were also higher in girls than boys (both P < 0.01). A 51-60% increased risk of developing elevated blood pressure was observed for 1SD (standard deviation) increase of sex-specific BMI [1.60 (1.4-1.8); P < 0.0001] and waist/height ratio [1.51 (1.3-1.7); P < 0.0001].

CONCLUSION

Unique sex and ethnic differences in body composition and blood pressure exist in prepubescent children, with overweight/obesity increasing the risk of elevated blood pressure. Our findings support primary prevention strategies to combat the growing burden of hypertension and obesity-related diseases in youth.

TRIAL REGISTRATION

The study is registered on ClinicalTrials.gov (NCT04056377).