Exercise and Arterial Modulation in Children: The EXAMIN YOUTH Study

Effects of a cluster-randomized exercise intervention on cardiovascular health in preschoolers

Primary health prevention in at-risk children is receiving increased attention while less information is available on cardiovascular profile and response to exercise in healthy children. Our study examined the effects of a gross motor skill-based exercise intervention on micro- and macro-vascular health in preschoolers. This is a sub-study of a five-armed clinical trial with six kindergartens and 68 children. Four kindergartens were assigned to the intervention group (INT) and two to control groups (CON). We performed gross motor skill assessment (TGMD-2), static retinal vessel analysis, and measurements of central hemodynamics before and after the intervention. INT received one weekly exercise session for 25 weeks, while CON received no intervention. We calculated linear regressions correcting for age, sex, BMI-percentile, and baseline. We observed favorable effects in TGMD-2 for INT over CON (Cohen's d = 0.52 95% CI [0.15; 0.90]). Trivial between-group differences were observed in retinal vessel diameters (0.08 < d ≤ 0.29) and trivial to moderate differences in all other arterial stiffness parameters (-0.55 < d ≤ 0.31). Motor-skill based interventions are sensible measures to incorporate physical activity in pre-schools and improve gross motor proficiency at a very young age. The potential of motor skill-based interventions as primordial prevention strategy in healthy preschoolers needs to be further investigated.

Bivariate relation of vascular health and blood pressure progression during childhood

BACKGROUND AND AIMS

Hypertension is a major risk factor for the development of cardiovascular disease (CVD) in adulthood. High blood pressure (BP) is associated with subclinical vascular impairments as early as childhood. We aimed to assess the association of retinal microvascular diameters and large artery pulse wave velocity (PWV) with progression of childhood BP.

METHODS

In our prospective Basel cohort study, 1171 children aged 6-8 years were screened for BP, body mass index, retinal vessel diameters and PWV using standardized protocols. After 4 years, all parameters were assessed in 749 children using the same protocols.

RESULTS

Children with narrower central retinal arteriolar diameters (CRAE) and higher PWV at baseline developed higher systolic BP after 4 years (β [95% CI] 0.6 [0.072 to 1.164] mmHg per 10 μm decrease, p = 0.026 and β [95% CI] 0.6 [0.331 to 0.838] mmHg per 0.1 m/s increase, p < 0.001, respectively). Children with increased systolic BP at baseline developed narrower CRAE and higher PWV at follow-up (β [95% CI] -3.3 [-4.43 to -2.09] μm per 10 mmHg increase, p < 0.001 and β [95% CI] 0.13 [0.10 to 0.16] m/s per 10 mmHg increase, p < 0.001, respectively).

CONCLUSIONS

Retinal arteriolar diameter and PWV independently predict progression of childhood BP, while initial BP is linked to development of micro- and macrovascular impairments, describing a bivariate temporal relationship between vascular health and BP. Childhood may present a window of opportunity for initiation of primary prevention strategies for the treatment of high BP to help prevent manifestation of CVD later in life.

Evaluation of aortic biomechanics in patients with aortic disease via imaging: A review

As a bridge between the heart and the arteries, the aorta plays an important role in the cardiovascular system. The morbidity and mortality of aortic disease are extremely high, which is a serious threat to human life. The biomechanical abnormality of the aorta is an important factor of a series of pathological changes in the aortic wall. At present, there are many imaging methods to evaluate the biomechanics of the aorta, which will benefit to the early diagnosis and treatment of aortic disease. In this review, we describe the application of various imaging methods and parameters in aortic disease.

Elevated blood pressure positively associates with alpha-1 microglobulin in prepubescent children: the ExAMIN Youth SA study

OBJECTIVES AND METHODS

Hypertension is a growing health concern in childhood populations and individuals of African descent. As the kidneys play a significant role in blood pressure regulation, we compared alpha-1 microglobulin (A1M) as a marker of proximal tubular function between young healthy black and white children (n = 957; aged: 5-9 years) and explored its association with blood pressure.

RESULTS

The black children had higher levels of A1M (P < 0.001) and higher DBP (P < 0.001) when compared with their white counterparts. In multiple regression analysis, SBP (adj. R2 = 0.173, β = 0.151; P < 0.001) and DBP (adj. R2 = 0.110, β = 0.179; P < 0.001) associated positively with A1M in the black children. In binary logistic regression, each standard deviation increase in A1M increased the odds of having elevated blood pressure by 28% (P = 0.002) in the black group, independent of age, sex, BMI z-score and body height. No significance was reached in the white children.

CONCLUSION

Our findings highlight the importance of a marker of proximal tubular function, especially in children of black ethnicity, in the setting of elevated blood pressure. Early childhood screening for elevated blood pressure remains essential in order to promote primary prevention of hypertension and early onset kidney damage in children.

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).

Socioeconomic Status and Parental Lifestyle Are Associated With Vascular Phenotype in Children

Background/Aims: Socioeconomic barriers and lifestyle conditions affect development of cardiovascular disease in adults, but little is known about the association of parental lifestyle and education with childhood health. We aimed to investigate the association of socioeconomic status (SES), migration background, parental physical activity (PA) and smoking status with micro-and macrovascular health in children. Methods: In 2016/2017, 833 school children (aged 7.2 ± 0.4 years) in Basel (Switzerland) were screened for retinal arteriolar-to-venular ratio (AVR), pulse wave velocity (PWV), SES, migration background and parental PA as well as smoking status. Results: High parental PA levels were associated with a favorable higher AVR (p = 0.020) and lower PWV (p = 0.035), but not independent of parental smoking status. Children with parents who smoked had a higher PWV [4.39 (4.35-4.42) m/s] compared to children with non-smoking parents [4.32 (4.29-4.34) m/s, p = 0.001]. Children of parents with a low household income had a higher PWV [4.36 (4.32-4.41) m/s] compared to children of parents with a high household income [4.30 (4.26-4.34) m/s, p = 0.033]. Low parental educational level was associated with a lower AVR [0.86 (0.85-0.88)] compared to children with highly educated parents [AVR:0.88 (0.87-0.88), p = 0.007; PWV: 4.33 (4.30-4.35) m/s, p = 0.041]. Children with a European background showed a higher AVR [0.88 (0.87-0.88)] compared to non-European children [AVR: (0.86 (0.85-0.87), p = 0.034]. Conclusion: Parental PA is associated with better macro- and microvascular childhood health. However, the positive association is lost when parental smoking is considered in the analysis. Socioeconomic factors seem to associate with subclinical vascular alterations in children. Primary prevention programs should focus on including parental lifestyle interventions and educational programs to reduce the burden of lifestyle-associated barriers in order to improve cardiovascular health during lifespan. Clinical Trial Registration: ClinicalTrials.gov Exercise and Arterial Modulation in Youth, https://clinicaltrials.gov/ct2/show/NCT02853747, NCT02853747.

Body Composition and Physical Fitness Affect Central Hemodynamics in Young Children

Objective: Central hemodynamics are related to cardiovascular (CV) outcomes in adults, but associations with childhood CV risk remain unclear. The study aimed to investigate the association of obesity, physical activity, and fitness with parameters of central pulse wave reflection in young prepubertal children. Methods: In this cross-sectional study, 1,324 primary school children (aged 7.2 ± 0.4 years) were screened for parameters of pulse wave reflection such as augmentation index (AIx), central pulse pressure (CPP), body mass index (BMI), and cardiorespiratory fitness (CRF) by standardized procedures for children. Results: The mean AIx and AIx@75 were 22.2 ± 7.7 and 29.2 ± 9.2%, respectively. With each unit increase in BMI, AIx [-0.226 (-0.328; -0.125)%] and AIx@75 [-0.444(-0.660; -0.229)%] decreased, whereas peak forward pulse wave increased (p < 0.001). Increasing BMI was associated with higher CPP, but did not remain significant after adjustment for CRF and heart rate. One unit increase in CRF was associated with lower AIx@75 [-0.509(-0.844; -0.173)%, p = 0.003] and lower reflection magnitude [RM: -0.559 (-0.890; -0.227), p = 0.001], independent of body weight and height. Girls had significantly higher AIx, AIx@75, peak backward pulse wave, and RM compared with boys. Conclusion: Childhood obesity was associated with higher CPP but lower augmentation of the reflected pulse wave in children. Assessment of central blood pressures appears to be a valuable asset to childhood CV risk screening. The validity of augmentation indices during childhood development and the association with early vascular aging in children need to be verified in long-term follow-up studies. Physical activity and fitness have the potential to improve vascular hemodynamics in susceptible children and, thus, counteract vascular aging. Trial registry: ClinicalTrials.gov: Exercise and Arterial Modulation in Youth. Identifier: NCT02853747; URL: https://clinicaltrials.gov/ct2/show/NCT02853747.

Metabolically Healthy Obesity: Presence of Arterial Stiffness in the Prepubescent Population

Aim: Arteriosclerotic cardiovascular disease, one of the world’s leading causes of death, first manifests itself at an early age. The identification of children who may have increased cardiovascular risk in the future could be an important prevention strategy. Our aim was to assess the clinical, analytical, and dietary variables associated with arterial stiffness (AS), measured by carotid-femoral pulse wave velocity (cfPWV) in a prepubescent population with metabolically healthy obesity (MHO). Subjects and Methods: A cross-sectional study in prepubescent subjects with obesity who had ≤1 metabolic syndrome criteria (abdominal perimeter and blood pressure ≥90th percentile, triglycerides >150 mg/dL, HDL-cholesterol <40 mg/dL, fasting plasma glucose ≥100 mg/dL) was conducted. Adherence to Mediterranean Diet, blood pressure, BMI, waist/height ratio (WHtR), glycemic status, lipid profile, and cfPWV were analyzed. 75 MHO children (boys: 43; girls: 32; p = 0.20) (age = 10.05 ± 1.29 years; BMI = 25.29 ± 3.5 kg/m2) were included. Results: We found a positive correlation between cfPWV and weight (r = 0.51; p < 0.0001), BMI (r = 0.44; p < 0.0001), WHtR (r = 0.26; p = 0.02), fasting insulin levels (r = 0.28; p = 0.02), and insulin resistance (Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) index) (r = 0.25; p = 0.04). Multiple linear regression analysis identified BMI and HOMA-IR as independent parameters associated with cfPWV. Conclusions: Prepubescent children with obesity who were shown to be metabolically healthy presented with arterial stiffness, which is closely related to BMI and the state of insulin resistance.

Cardiovascular Risk Markers and Cognitive Performance in Children

Markers of cardiovascular risk and cognitive performance were assessed in 347 children. In contrast with body mass index and blood pressure, only retinal microcirculation explained a unique proportion of variance in inhibitory control and information processing, when dependencies between markers of cardiovascular risk were accounted for.

The Exercise, Arterial Modulation and Nutrition in Youth South Africa Study (ExAMIN Youth SA)

Background: The impact of a sedentary and unhealthy lifestyle on cardiovascular health is well-documented, however the current obesity and hypertension trends among children is concerning. The ExAMIN Youth SA study aims to investigate the impact of lifestyle behaviors (physical fitness/activity, dietary intake and psychosocial factors) involved in early vascular aging among South African children. Methods: This study is an analytical, multidisciplinary, observational cohort study in a school-based setting. We aim to phenotype a cohort of ~1,000 primary school children (black and white boys and girls between ages 5-9 years) based on current clinical childhood conditions including hypertension and obesity. The primary phenotype is large artery stiffness and retinal microvascular diameters, both biomarkers of early vascular aging. The risk factors and mediators of early vascular aging and also responsible for the clinical conditions include physical inactivity, unhealthy diet, and life stress. Additionally, urinalysis and salivary analyses will be performed to identify biomarkers related to the pathophysiology of early vascular aging. Discussion: In line with the growing prevalence of obesity and hypertension responsible for the development of early vascular aging from childhood to adulthood, this study will address the critical areas in which we observe unfavorable arterial modulation related to dietary behaviors, physical inactivity, and early life stress. Implementation of novel biological markers may further contribute to our understanding of early cardiovascular adaptations in childhood, and aid in the development of primary prevention programs. Trial registration: The study was retrospectively registered on ClinicalTrials.gov on 15 August 2019 (NCT04056377).