Arterial stiffness and endothelial function in obese children and adolescents and its relationship with cardiovascular risk factors

Vascular and autonomic function as early predictive biomarkers of the progression to gestational hypertension

Background

The changes in endothelial function, arterial stiffness, and heart rate variability (HRV) produced in the first trimester of pregnancy in women who develop gestational hypertension (GH) are still being investigated. Objective: to evaluate the HVR, endothelial function, and arterial stiffness changes during the first trimester of pregnancy and their relationship with the development of GH.

Methods

A group of women normotensive during the first trimester (n = 43), who later did (GH; n = 11) or did not (no-GH; n = 32) develop GH in that pregnancy, were enrolled. In the first trimester, endothelial function and arterial stiffness were evaluated through photoplethysmography. HRV, parasympathetic (PNS), and sympathetic (SNS) indexes were measured in a 5-minute continuous electrocardiogram record at rest sitting. The Griess reaction measured urinary nitrite excretion (NOx).

Results

Systolic blood pressure (SBP) values were higher in GH (no-GH: 105.8 ± 2.0 vs. GH: 112.7 ± 3.0 mmHg; p < 0.05). Endothelial function was decreased, and arterial stiffness was increased in GH. Only in GH the arterial stiffness was correlated with SBP (Pearson's r: 0.5594; 95%CI: 0.06106-0.8681; p < 0.05). In HRV, GH decreased low-frequency power and the ratio SD2/SD1. The inhibition of PNS was lower in GH. The NOx was reduced in GH (no-GH: 3.4 ± 0.4 vs. GH: 0.3 ± 0.1 μM/L; p < 0.001). NOx was correlated negatively with the SNS index only in GH.

Conclusions

Developed GH is preceded early in pregnancy by endothelial dysfunction and increased arterial stiffness. In this context, there are SNS-PNS interrelation modifications with less inhibition of PNS.

Association of blood pressure, obesity and physical activity with arterial stiffness in children: a systematic review and meta-analysis

Central pulse wave velocity (cPWV) is a biomarker for cardiovascular (CV) risk and a predictor for CV events in adulthood. Alterations of arterial stiffness have also been associated with CV risk in childhood. The study aimed to systematically review and meta-analyze the association of blood pressure (BP), body mass index (BMI), and cardiorespiratory fitness (CRF) with cPWV in children. Literature search was through the databases PubMed, Web of Science, Embase and the Cochrane Register of Controlled Trials. Twenty-two articles were included in the systematic review and eight articles in the meta-analysis. Higher systolic and diastolic BP were associated with higher cPWV (pooled estimated effect size (ES) 0.02 (95% CI: 0.012-0.027; P < 0.001), and ES 0.02 (95% CI: 0.011-0.029; P < 0.001); respectively). Higher BMI correlated with higher cPWV (ES 0.025 (95% CI: 0.013-0.038; P < 0.001)). CRF was inversely associated with cPWV (ES -0.033 (95% CI: -0.055 to -0.011; P = 0.002)). In children, higher BP and BMI are already related to increased cPWV, and enhanced CRF may be a preventive strategy to counteract development of CV disease later in life. IMPACT: This meta-analysis suggests that elevated blood pressure and body mass index in childhood correlate with increased central pulse wave velocity. Children with higher cardiorespiratory fitness appear to have favorably lower arterial stiffening. Elevated blood pressure and altered arterial stiffness originate early in life and childhood risk stratification as well as timely initiation of exercise treatment may help counteract development of manifest cardiovascular disease later in life.

Changes in vascular function and autonomic balance during the first trimester of pregnancy and its relationship with the new-born weight

This study aimed to evaluate vascular function changes and autonomic balance during the first trimester of pregnancy and its relationship with the new-born weight. This prospective study performed in pregnant (PG) women and after delivery (not pregnant: NPG) evaluated the endothelial function (EF) and arterial stiffness (AS) by a non-invasive method. We evaluated the heart rate variability (HRV), parasympathetic nervous system (PNS), sympathetic nervous system (SNS) indexes by electrocardiogram (5 min) and the urinary nitrite excretion (NOx). PG increased EF and NOx and decreased AS and HRV. PG decreased the PNS index and augmented the SNS index. The new-born weight positively correlated with the PNS index (Pearson's r: 0.4291; p<.05), NOx, HRV and negatively correlated with AS. In summary, in pregnancy, although haemodynamically, the SNS activation plays a compensatory role, the low rates of PNS inhibition are essential to ensure normal foetal growth.Impact StatementWhat is already known on this subject? In pregnancy, there are adaptive physiological changes in the cardiovascular system that include increases of EF and decreases AS with an SNS activation. The study of HRV lets to predict the SNS and PNS balance and how they affect blood pressure and vascular function.What the results of this study add? Although it is known that SNS activation plays a compensatory role in healthy pregnancy, this study adds the critical role of PNS. Early in pregnancy, the low rates of PNS inhibition are essential to ensure normal foetal growth.What the implications are of these findings for clinical practice and/or further research? The present results show a potential predictive value of SNS and PNS activity early in pregnancy. It will provide valuable information not only on the pregnant woman's vascular function but also on the new-born weight.

Oral glucose tolerance response curve predicts disposition index but not other cardiometabolic risk factors in healthy adolescents

OBJECTIVES

In obese adults the shape of the glucose response curve during an oral glucose tolerance test (OGTT) predicts future type 2 diabetes. Patients with an incessant increase or monophasic curves have increased risk compared to those with biphasic curves. Since type 2 diabetes is associated with increased cardiometabolic risk, we studied whether differences in OGTT response curve are associated with differences in cardiometabolic risk factors in healthy adolescents across a wide body mass index (BMI) range.

METHODS

Sixty-nine (33F/36M), white adolescents (age: 15.2 ± 1.7 years; BMI: 21.5 ± 4.7 kg/m2; mean ± SD) were studied. Risk factors measured included percent body fat, blood pressure, lipids, augmentation index, reactive hyperemia, endothelin 1, plasminogen activator 1, inflammatory markers (interleukin 6, c-reactive protein), insulin secretion, insulin sensitivity (Matusda index), and disposition index (DI).

RESULTS

Thirty-two subjects had biphasic responses; 35 subjects had monophasic responses and two females had incessant increases. Sex did not affect the frequency of responses. Glucose area under the curve during OGTT was greater in those with a mono vs. biphasic curves (p=0.01). Disposition index was markedly lower in subjects with a monophasic curve than in those with a biphasic curve (3.6 [2.3-5.0] vs. 5.8 [3.8-7.6], median [25th, 75th%] p=0.003). Triglyceride to high-density lipoprotein cholesterol (HDL) ratio was higher in subjects with a monophasic curve (p=0.046).

CONCLUSIONS

The decreased disposition index indicates that in healthy adolescents a monophasic response to OGTT is due to decreased insulin secretion relative to the degree of insulin resistance present. This was not associated with differences in most other cardiometabolic risk markers.

TRIAL REGISTRATION

Clinical Trials.gov, NCT02821104.

Relationship of Obesity and Related Disorders with Ocular Parameters in Children and Adolescent

PURPOSE

To evaluate the effect of obesity and obesity-related high blood pressure (BP) on the retinal nerve fiber layer (RNFL) and macula in children and adolescents.

MATERIALS AND METHODS

Thirty-two obese patients followed up in the pediatrics endocrinology clinic between 2018 and 2019 were evaluated in the ophthalmology clinic. The results were compared with 25 healthy subjects, matched for age and sex. Anthropometric measurements, and systolic and diastolic BP were measured. The study consisted of three groups: Group 1, patients with obesity; Group 2, those with obesity and associated hypertension (obesity-related HT); and Group 3, healthy controls. A complete ophthalmologic examination was performed. Macular and RNFL thicknesses were determined using spectral domain optical coherence tomography (SD-OCT).

RESULTS

There were no statistically significant differences between the groups in terms of gender, age, and intraocular pressure (p > .05). The inferior RNFL thickness and central foveal thickness were statistically thinner in the obesity-related HT group (p < .001 and p = .040). The systolic and diastolic BP and fasting glucose values were significantly higher in the obesity-related HT group than the other groups (p < .001; p < .001; p = .026, respectively). In linear regression modeling in obese and obesity-related HT groups, a significant assocation was found between diastolic BP and temporal RNFL thickness (p = .027) as well as between the systolic BP and triglyceride values and the nasal RNFL thickness values (p = .016 and p = .025, respectively).

CONCLUSIONS

Inferior RNFL thickness and central foveal thickness were significantly thinner in patients with obesity-related HT. The effects of obesity-related HT on the retina should be evaluated using SD OCT, since no signs were found in a routine ocular examination.

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.

Increased body fat and reduced insulin sensitivity are associated with impaired endothelial function and subendocardial viability in healthy, non-Hispanic white adolescents

BACKGROUND

Cardiovascular disease has its origins in adolescents. Endothelial dysfunction, arterial stiffness, and decreased endocardial oxygen supply: demand ratios are early functional markers of cardiovascular risk. The goal of this study was to determine the relationships of these markers to physical, inflammatory, and metabolic markers in healthy non-Hispanic, white adolescents.

METHODS

Thirty-four of the 75 subjects were female. Mean age was 15.0 ± 1.7 years and mean body mass index (BMI) was 22.0 ± 5.8 kg/m² (mean ± SD). Reactive hyperemia was measured using venous occlusion plethysmography. Arterial tonometry was used to measure the augmentation index (AIx₇₅ ) and the Buckberg subendocardial viability ratio. Blood samples were taken to measure inflammatory and lipid markers and oral glucose tolerance test was used to assess insulin sensitivity.

RESULTS

Reactive hyperemia decreased as body mass and fat mass increased. It also decreased with increasing neutrophil count. The Buckberg index was higher in males and was positively related to insulin sensitivity even when accounting for age, sex, and resting heart rate. AIx₇₅ was not related to any of the other variables.

CONCLUSIONS

These results demonstrate that increased fat mass and decreased insulin sensitivity are related to poorer vascular function and cardiac risk in adolescents before the development of actual cardiovascular disease.

Effects of Tai Chi on Cerebral Hemodynamics and Health-Related Outcomes in Older Community Adults at Risk of Ischemic Stroke: A Randomized Controlled Trial

This study investigated the effects of Tai Chi compared with no exercise control on the cerebral hemodynamic parameters and other health-related factors in community older adults at risk of ischemic stroke. A total of 170 eligible participants were randomly allocated to Tai Chi or control group. The cerebral hemodynamic parameters and physical fitness risk factors of cardiovascular disease were measured at baseline, 12 weeks, and 24 weeks. After the 12-week intervention, Tai Chi significantly improved the minimum of blood flow velocity (BFVmin); BFVmean; pulsatility index and resistance index of the right anterior cerebral artery; and BFVmax, BFVmin, and BFVmeanparameters of the right middle cerebral artery. Tai Chi training also decreased triglyceride, fasting blood glucose, and homocysteine levels, and improved balance ability. Therefore, the supervised 12-week Tai Chi exercise had potential beneficial effects on cerebral hemodynamics, plasma risk factors, and balance ability in older community adults at risk of ischemic stroke.

Comparison of retinal vascular geometry in obese and non-obese children

Purpose

Childhood obesity is associated with adult cardiometabolic disease. We postulate that the underlying microvascular dysfunction begins in childhood. We thus aimed to compare retinal vascular parameters between obese and non-obese children.

Methods

This was a cross-sectional study involving 166 children aged 6 to 12 years old in Malaysia. Ocular examination, biometry, retinal photography, blood pressure and body mass index measurement were performed. Participants were divided into two groups; obese and non-obese. Retinal vascular parameters were measured using validated software.

Results

Mean age was 9.58 years. Approximately 51.2% were obese. Obese children had significantly narrower retinal arteriolar caliber (F_(1,159) = 6.862, p = 0.010), lower arteriovenous ratio (F_(1,159) = 17.412, p < 0.001), higher venular fractal dimension (F_(1,159) = 4.313, p = 0.039) and higher venular curvature tortuosity (F_(1,158) = 5.166, p = 0.024) than non-obese children, after adjustment for age, gender, blood pressure and axial length.

Conclusions

Obese children have abnormal retinal vascular geometry. These findings suggest that childhood obesity is characterized by early microvascular abnormalities that precede development of overt disease. Further research is warranted to determine if these parameters represent viable biomarkers for risk stratification in obesity.

Effects of High-Intensity Intermittent Training on Vascular Function in Obese Preadolescent Boys

BACKGROUND

High-intensity intermittent training (HIIT) may serve as an effective alternative to traditional endurance training, since HIIT has been shown to induce greater improvements in aerobic fitness and health-related markers in adult populations. Our objective was to determine whether HIIT and supramaximal high-intensity intermittent training (supra-HIIT) would improve vascular structure and function in obese preadolescent boys.

METHODS

Before the baseline testing, 48 obese preadolescent boys, aged 8-12 years, were randomly assigned into control (CON; n = 16), HIIT (8 × 2 minutes at 90% peak power output, n = 16), and supra-HIIT (8 × 20 seconds at 170% peak power output, n = 16) groups. Both exercise groups performed exercises on a cycle ergometer three times/week for 12 weeks.

RESULTS

After 12 weeks, both HIIT and supra-HIIT did not affect body mass, body fat percentage, and waist circumference. Peak oxygen consumption (VO₂peak) increased in both HIIT and supra-HIIT groups (p < 0.05). Both HIIT and supra-HIIT groups had higher resting metabolic rate than the control group (p < 0.05). A measure of arterial stiffness, brachial-ankle pulse wave velocity, and carotid intima-media thickness decreased after 12 weeks of HIIT and supra-HIIT program (all p < 0.05). Flow-mediated dilation, a measure of endothelium-dependent vasodilation, increased in both HIIT and supra-HIIT groups (all p < 0.05).

CONCLUSIONS

It is concluded that both HIIT and supra-HIIT have favorable effects on aerobic capacity, metabolic rate, vascular function and structure, and blood lipid profile in obese preadolescent boys. HIIT may be a time efficient and effective exercise for preventing future cardiovascular disease in obese children.

Vascular Function in Children with Low Birthweight and Its Relationship with Early Markers of Cardiovascular Risk

Low birthweight (LBW) increases the risk of developing cardiovascular diseases (CVD). Few studies have established its impact at early ages.

AIMS

To study endothelial function (EF) and arterial stiffness (AS) and their relationship to early markers of CVD risk in children with LBW.

METHODS

In children with LBW (4-6 years; n = 53), anthropometric, haemodynamic and laboratory parameters, including HOMA-IR, hs-CRP, adiponectin and leptin, were determined. EF and AS were evaluated by digital pulse plethysmography. Data were compared with a control group (n = 33).

RESULTS

In both groups, anthropometric parameters remained within normal limits. Insulin and HOMA-IR had normal values, but they were significantly augmented in LBW children. LBW children showed higher leptin and hs-CRP levels than the control group. The LBW group had decreased EF (37.5 ± 5.6%) compared with the control group (75.0 ± 11.9%; p < 0.01), however without differences in AS. In LBW children, EF was negatively correlated with waist circumference, leptin, hs-CRP and with a cumulative score of risk factors.

CONCLUSIONS

LBW children display altered EF that is related to early changes in CVD risk factors. The differences found in the metabolic parameters might indicate a pro-inflammatory state. This hypothesis is also supported by the laboratory findings and the correlation between EF and the number of CVD risk factors, suggesting that very early lifestyle interventions may be needed.

Determinants of carotid-femoral pulse wave velocity in prepubertal children

BACKGROUND

Pulse wave velocity (PWV) is a noninvasive technique to evaluate arterial stiffness, a dynamic property of the vessels, reflecting their structure and function. Childhood obesity is associated with several cardiovascular comorbidities and to the progression of atherosclerosis. We aimed to compare carotid-femoral PWV between normal weight and overweight/obese prepubertal children and to quantify its association with other cardiovascular risk factors.

METHODS

Cross-sectional study of 315 children aged 8-9years. Anthropometrics, 24-h ambulatory blood pressure (BP) and carotid-femoral PWV were measured. Classification of obesity was according to World Health Organization (WHO) body mass index (BMI)-for-age reference values.

RESULTS

Compared to normal weight children, overweight and obese children presented significantly higher levels of PWV (4.95 (P25-P75: 4.61-5.23), 5.00 (4.71-5.33), 5.10 (4.82-5.50) m/s, respectively; ptrend<0.001). Significant positive correlations were found between PWV and total cholesterol, LDL cholesterol, triglycerides, fasting insulin and insulin resistance levels (HOMA-IR) and with high-sensitivity C-reactive protein (hs-CRP). In a multivariate linear regression model adjusted for sex, age, height and 24-h systolic blood pressure z-score, the independent determinants of PWV were BMI, HOMA-IR and the absence of dipping.

CONCLUSIONS

The association between PWV and the loss of dipping and insulin resistance levels, independently of the BMI, reinforces the contribution of these comorbidities to vascular injury in early life.

Intima-media thickness and arterial function in obese and non-obese children

Background

Obesity is an independent cardiovascular risk factor that contributes to the development of atherosclerosis. Subclinical forms of the disease can be assessed via sonographic measurement of carotid intima-media thickness (cIMT) and distensibility – both may already be altered in childhood. As childhood obesity increases to an alarming extent, this study compares vascular data of obese with normal weight boys and girls to investigate the influence of obesity on cIMT and distensibility of the carotid arteries.

Methods

cIMT and distensibility of 46 obese children (27 girls) aged 7–17 years were compared with measures of 46 sex- and age-matched normal weight controls. cIMT and distensibility were measured by B- and M-mode ultrasound and expressed as standard deviation scores (SDS). Arterial distensibility was defined by arterial compliance (AC), elastic modulus (Ep), stiffness index β (β), and local pulse wave velocity β (PWV β).

Results

Obese girls had significantly stiffer arteries compared with normal weight girls (Ep SDS 0.64 ± 1.24 vs. 0 ± 1.06, β SDS 0.6 ± 1.17 vs. -0.01 ± 1.06 p < .01, PWV β 0.54 ± 1.2 vs. -0.12 ± 1.05 p < .05). No significant differences were observed for boys. In multiregression analysis, BMI significantly influenced Ep, β and PWV β but not cIMT and AC.

Conclusions

Obese girls seemed to be at higher cardiovascular risk than boys, expressed by stiffer arteries in obese girls compared with normal weight girls. Overall, BMI negatively influenced parameters of arterial stiffness (Ep, β and PWV β) but not compliance or cIMT.

Objectively measured physical activity and sedentary-time are associated with arterial stiffness in Brazilian young adults

OBJECTIVE

To examine the associations between objectively measured physical activity and sedentary time with pulse wave velocity (PWV) in Brazilian young adults.

METHODS

Cross-sectional analysis with participants of the 1982 Pelotas (Brazil) Birth Cohort who were followed-up from birth to 30 years of age. Overall physical activity (PA) assessed as the average acceleration (mg), time spent in moderate-to-vigorous physical activity (MVPA - min/day) and sedentary time (min/day) were calculated from acceleration data. Carotid-femoral PWV (m/s) was assessed using a portable ultrasound. Systolic and diastolic blood pressure (SBP/DBP), waist circumference (WC) and body mass index (BMI) were analyzed as possible mediators. Multiple linear regression and g-computation formula were used in the analyses.

RESULTS

Complete data were available for 1241 individuals. PWV was significantly lower in the two highest quartiles of overall PA (0.26 m/s) compared with the lowest quartile. Participants in the highest quartile of sedentary time had 0.39 m/s higher PWV (95%CI: 0.20; 0.57) than those in the lowest quartile. Individuals achieving ≥30 min/day in MVPA had lower PWV (β = -0.35; 95%CI: -0.56; -0.14). Mutually adjusted analyses between MVPA and sedentary time and PWV changed the coefficients, although results from sedentary time remained more consistent. WC captured 44% of the association between MVPA and PWV. DBP explained 46% of the association between acceleration and PWV.

CONCLUSIONS

Physical activity was inversely related to PWV in young adults, whereas sedentary time was positively associated. Such associations were only partially mediated by WC and DBP.

BMI, body fat mass and plasma leptin level in relation to cardiovascular diseases risk factors among adolescents in Taitung

BACKGROUND

To investigate the risk factors associated with cardiovascular diseases and its relation to BMI, body fat mass and plasma leptin level among adolescents in Taitung, Taiwan.

METHODS

A cross-sectional Taitung Children Heart Study for 500 young adolescents between ages 13 and 15 was conducted. Gender-specific regression models were used to determine the associations between BMI, percentage of body fat mass, plasma leptin level and seven CVDs risk factors (systolic and diastolic blood pressure, mean arterial pressure, triglycerides, total cholesterol, HDL-cholesterol and LDL-cholesterol) before and after adjusting for weight status and age.

RESULTS

After adjusting for weight status and age, BMI was positively associated with systolic BP, triglycerides, LDL-cholesterol levels but negatively associated with HDL-cholesterol level in boys while positively associated with systolic and diastolic BP, mean arterial pressure, and LDL-cholesterol level in girls. The percentage of body fat mass was positively associated with triglycerides, total cholesterol, and LDL-cholesterol in boys while positively associated with systolic BP, total cholesterol, and LDL-cholesterol in girls. Plasma leptin was positively associated with triglycerides, total cholesterol and LDL-cholesterol in boys but no statistically significant associations with CVDs risk factors in girls. A strong relationship between the percentage of body fat mass and plasma leptin appeared among all participants (r=0.59, p<0.01).

CONCLUSIONS

BMI, body fat mass and plasma leptin level may be used to identify certain CVDs risk factors among Taitung adolescents. Future researches could consider measuring body fat mass in the relationship of CVDs risk factors instead of plasma leptin among young adolescents.