Distensibility of the Aorta and Carotid Artery and Left Ventricular Mass From Childhood to Early Adulthood

Arterial Stiffness and Carotid Intima-Media Thickness in Children Exposed to Smokeless Tobacco in Fetal Life

BACKGROUND

Arterial stiffening and increased intima-media thickness can be seen as early as childhood and are associated with increased risk of cardiovascular events in adult life. The authors hypothesized that exposure to prenatal smokeless tobacco (Swedish snus) without additional nicotine exposure after the breastfeeding period would be associated with increased arterial stiffness and intima-media thickening in preschool children.

METHODS AND RESULTS

This was a longitudinal follow-up cohort study of children aged 5 to 6 years exposed to high doses of nicotine in utero. Women exclusively using snus and unexposed controls were enrolled in early pregnancy (gestational age range, 6-12 weeks). Exposure data were collected during and after pregnancy with questionnaires from both groups. For this study, only children of women using >48 mg nicotine per day during their entire pregnancy were included in the exposure group. Outcomes were determined in 40 healthy children (21 exposed to snus in utero). Ultrasonography of the common carotid artery was used to determine carotid intima-media thickness and calculate arterial stiffness index from the relationship between pulsatile changes in arterial diameter and arterial pressure. Children exposed to snus in fetal life had higher carotid stiffness (median 4.1 [interquartile range (IQR), 2.4-5] versus 2.9 [IQR, 2.1-3.5]; P=0.014) than tobacco-free controls. Carotid strain (relative diameter change) was lower in children exposed to snus (mean 16% [SD, 5.7%] versus 21% [SD, 6.6%]) than in controls (P=0.015). Carotid intima-media thickness did not differ significantly between children exposed to snus and controls.

CONCLUSIONS

Exposure to snus during fetal life was associated with a stiffer carotid artery in preschool children.

Assessment of Subclinical Atherosclerosis in Children with Atopic Dermatitis

INTRODUCTION

Data from studies conducted to date have evaluated clinical atherosclerotic conditions in adult patients with atopic dermatitis (AD). Subclinical atherosclerotic changes that are a precursor of atherosclerotic conditions may begin in childhood. The aim of this study was to investigate the presence of subclinical atherosclerosis in pediatric patients with AD and to determine the associated risk factors.

METHODS

A total of 59 patients who were referred to our department over a 6-month period and diagnosed with AD, and 53 healthy controls with a similar age and gender were included in the study. Subclinical atherosclerosis markers (carotid intima media thickness [CIMT], distensibility, stiffness, and strain) were measured using conventional echocardiography. The patients' age, SCORAD index, and duration of symptoms were recorded. Serum total immunoglobulin E, C-reactive protein (CRP), blood lipid profile, and complete blood count markers were measured.

RESULTS

The median age of the patients was 61 (10-103) months, and 59.3% of them were male. The patients with AD had a higher CIMT (1.60 ± 0.35 vs. 1.30 ± 0.50 mm) and a lower distensibility (0.006 ± 0.009 vs. 0.01 ± 0.008) and strain (0.10 ± 0.14 vs. 0.19 ± 0.14) than the healthy controls (p < 0.01 for all), but there was no significant difference with regard to stiffness (10.16 ± 21.75 vs. 8.99 ± 12.66). Significant correlations between CIMT and disease duration, age, and the SCORAD index were found (p < 0.01, p < 0.01, and p < 0.05, respectively). No correlation between the subclinical atherosclerosis markers and the other laboratory results was found (p > 0.05 for all).

CONCLUSION

This study demonstrates that pediatric patients with AD may express subclinical atherosclerosis markers. The evaluation of subclinical atherosclerosis in these patients revealed that CIMT may be the most important marker, as it displayed positive correlations with symptom duration, age, and disease severity.

Optimised design of an arterial network model reproduces characteristic central and peripheral hemodynamic waveform features in young adults

Abstract

The arterial network in healthy young adults is thought to be structured to optimize wave reflection in the arterial system, producing an ascending aortic pressure waveform with three key features: early systolic peak, negative systolic augmentation and diastolic hump. One‐dimensional computer models have provided significant insights into arterial haemodynamics, but no previous models of the young adult have exhibited these three features. Given that this issue was likely to be related to unrepresentative or non‐optimized impedance properties of the model arterial networks, we developed a new ‘YoungAdult’ model that incorporated the following features: (i) a new and more accurate empirical equation for approximating wave speeds, based on area and relative distance to elastic–muscular arterial transition points; (ii) optimally matched arterial junctions; and (iii) an improved arterial network geometry that eliminated ‘within‐segment’ taper (which causes wave reflection in conduit arteries) whilst establishing ‘impedance‐preserving’ taper. These properties of the model led to wave reflection occurring predominantly at distal vascular beds, rather than in conduit arteries. The model predicted all three typical characteristics of an ascending aortic pressure waveform observed in young adults. When compared with non‐invasively acquired pressure and velocity measurements (obtained via tonometry and Doppler ultrasound in seven young adults), the model was also shown to reproduce the typical waveform morphology observed in the radial, brachial, carotid, temporal, femoral and tibial arteries. The YoungAdult model provides support for the concept that the arterial tree impedance in healthy young adults is exquisitely optimized, and it provides an important baseline model for investigating cardiovascular changes in ageing and disease states.

Key points

The origin of wave reflection in the arterial system is controversial, but reflection properties are likely to give rise to characteristic haemodynamic features in healthy young adults, including an early systolic peak, negative systolic augmentation and diastolic hump in the ascending aortic pressure waveform, and triphasic velocity profiles in peripheral arteries. Although computational modelling provides insights into arterial haemodynamics, no previous models have predicted all these features.

An established arterial network model was optimized by incorporating the following features: (i) a more accurate representation of arterial wave speeds; (ii) precisely matched junctions; and (iii) impedance‐preserving tapering, thereby minimizing wave reflection in conduit arteries in the forward direction. Comparison with in vivo data (n = 7 subjects) indicated that the characteristic waveform features in young adults were predicted accurately.

Our findings strongly imply that a healthy young arterial system is structured to optimize wave reflection in the main conduit arteries and that reflection of forward waves occurs primarily in the vicinity of vascular beds.

Digital Health in Primordial and Primary Stroke Prevention: A Systematic Review

The stroke burden continues to grow across the globe, disproportionally affecting developing countries. This burden cannot be effectively halted and reversed without effective and widely implemented primordial and primary stroke prevention measures, including those on the individual level. The unprecedented growth of smartphone and other digital technologies with digital solutions are now being used in almost every area of health, offering a unique opportunity to improve primordial and primary stroke prevention on the individual level. However, there are several issues that need to be considered to advance development and use this important digital strategy for primordial and primary stroke prevention. Using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines we provide a systematic review of the current knowledge, challenges, and opportunities of digital health in primordial and primary stroke prevention.

Vascular Ageing in Youth: A Call to Action

Extensive evidence shows that risk factors for cardiovascular disease (CVD) begin to develop early in life. Childhood obesity and elevated blood pressure (BP) have become overwhelmingly challenging, with 57% of today's children predicted to be obese by the age of 35 years, and global rates of hypertension in children and adolescents increasing by 75% from 2000 to 2015. Thus, there is an urgent need for tools that can assess early CVD risk in youth, which may lead to better risk stratification, preventative intervention, and personalised medicine. Vascular ageing (the deterioration in vascular structure and function) is a pivotal progenitor of health degeneration associated with elevated BP. Exposure to adverse environmental and genetic factors from fetal life promotes the development and accumulation of subclinical vascular changes that direct an individual towards a trajectory of early vascular ageing (EVA)-an independent predictor of target organ damage in the heart, brain, and kidneys. Therefore, characterising vascular ageing from youth may provide a window into cardiovascular risk later in life. However, vascular ageing measurements only have value when techniques are accurate/validated and when reliable thresholds are available for defining normal ranges and ranges that signal increased risk of disease. The aim of this paper is to summarise current evidence on the importance of vascular ageing assessment in youth and the impact of interventions to prevent or delay EVA, to highlight the need for standardisation and validation of measurement techniques in children and adolescents, and the importance of establishing reference values for vascular ageing measures in this population.

Physical activity is associated with lower pulsatile stress but not carotid stiffness in children

The cardiovascular disease (CVD) process may begin early in life when accompanied by atherosclerotic risk factors. CVD risk factors in children are associated with stiffening of the large elastic arteries, a reflection of subclinical atherosclerosis. Physical activity is a preventative lifestyle strategy that may benefit arterial stiffness by attenuating the hemodynamic stress on the artery wall. This study examined the relations between physical activity, carotid pulsatile stress, and carotid stiffness in children. One hundred and forty children (9-11 yrs; 50.0% male, 57.9% African American, 42.10% Caucasian, body mass index (BMI) 20.1±4.7 kg/m²) participated in this study. Physical activity counts were measured using a wrist-worn accelerometer and averaged over 7 days. Carotid artery β-stiffness and pulse pressure (calibrated to brachial mean and diastolic pressure) were assessed as via ultrasound and tonometry, respectively. Pulsatile stress was calculated as the product of carotid pulse pressure and heart rate. Physical activity counts were correlated with pulsatile stress (r= -0.27), and BMI (r= -0.23), but were unrelated to carotid stiffness. In multivariate models, associations between physical activity counts and pulsatile stress remained (B= -1.3 [95%CI, -2.4, -0.2], β= -0.20, p<0.05) after covariate adjustment for age, race, sex, pubertal stage and BMI. Carotid pulsatile stress was related to regional carotid stiffness (r=0.45, p<0.05). These data suggest that higher levels of physical activity at young age are associated with lower hemodynamic stress in the carotid artery. Findings are discussed in the context of an inverse relationship between hemodynamic pulsatile stress and carotid stiffness in children.

Subclinical cardiovascular dysfunction in children and adolescents with asthma

BACKGROUND

There is close association between asthma and cardiovascular functions as both diseases share common inflammatory pathways. The current study was aimed at investigating the risk factors, associated with endothelial and cardiac functions in children with newly-diagnosed mild-persistent asthma.

METHODS

A total of 33 steroid-naive asthmatic children [median(interquartile-range); 9.1 years(7.8-13.5)] and 16 healthy controls [11.5 years(9.9-13.6)] were included. Their demographic, clinical and laboratory findings were recorded. Carotid Artery intima-media thickness (CIMT), stiffness, distensibility and strain were measured as atheroclerosis markers. Conventional and tissue Doppler imaging was performed to evaluate ventricular function.

RESULTS

The patients with asthma had higher CIMT and stiffness and lower strain and distensibility compared to controls (p < 0.001 for all). There was a significant correlation between the duration of asthmatic symptoms and subclinical-atherosclerosis as well as peripheral eosinophil count (p < 0.001, p < 0.05). The patients had lower tricuspid-annular-plane-systolic-excursion (TAPSE), ejection time, and higher isovolumetric relaxation time (IRT), isovolumetric contraction time (ICT), and left ventricle myocardial performance index (LVMPI) than the control subjects (p < 0.001 for all). A positive correlation was also observed between the duration of asthmatic-symptoms and cardiac-function parameters.

CONCLUSION

Children with mild persistent asthma had subclinical atherosclerosis and ventricular dysfunction even in the early stage of disease. Symptom duration was closely associated with both subclinical atherosclerosis and ventricular dysfunction. Myocardial performance index was abnormal in the asthmatic children when assessed by tissue Doppler Imaging even though they had normal ejection fraction in conventional echocardiography. Future prospective studies with larger sample sizes are needed to confirm these findings and to assess the possible protective effect of ICSs in the prevention of subclinical atherosclerosis.

Dietary Fats and Atherosclerosis From Childhood to Adulthood

BACKGROUND

The association of dietary fat distribution with markers of subclinical atherosclerosis during early life is unknown. We examined whether success in achieving the main target of an infancy-onset dietary intervention based on the distribution of dietary fat was associated with aortic and carotid intima-media thickness (IMT) and distensibility from childhood to young adulthood.

METHODS

In the prospective randomized controlled Special Turku Coronary Risk Factor Intervention Project trial, personalized dietary counseling was given biannually to healthy children from infancy to young adulthood. The counseling was based on Nordic Nutrition Recommendations, with the main aim of improving the distribution of dietary fat in children's diets. IMT and distensibility of the abdominal aorta and common carotid artery were measured repeatedly at ages 11 (n = 439), 13 (n = 499), 15 (n = 506), 17 (n = 477), and 19 years (n = 429). The targeted distribution of dietary fat was defined as a ratio of saturated fatty acids to monounsaturated and polyunsaturated fatty acids of <1:2 and as an intake of saturated fatty acids of <10% of energy intake. Participants who met ≥1 of these 2 criteria were defined to achieve the main intervention target.

RESULTS

Individuals who achieved the main intervention target had lower aortic IMT (age- and sex-adjusted mean difference 10.4 µm; 95% confidence interval: 0.3 to 20.5 µm) and better aortic distensibility (0.13% per 10 mm Hg; 95% confidence interval: 0.00% to 0.26% per10 mm Hg) compared with their peers who did not meet the target.

CONCLUSIONS

Achieving the main target of an infancy-onset dietary intervention, reflecting dietary guidelines, was favorably associated with aortic IMT and distensibility during the early life course. These data support the recommendation of favoring unsaturated fat to enhance arterial health.

Vascular characteristics in young women-Effect of extensive endurance training or a sedentary lifestyle

AIM

To explore whether high-level endurance training in early age has an influence on the arterial wall properties in young women.

METHODS

Forty-seven athletes (ATH) and 52 controls (CTR), all 17-25 years of age, were further divided into runners (RUN), whole-body endurance athletes (WBA), sedentary controls (SC) and normally active controls (AC). Two-dimensional ultrasound scanning of the carotid arteries was conducted to determine local common carotid artery (CCA) geometry and wall distensibility. Pulse waves were recorded with a tonometer to determine regional pulse wave velocity (PWV) and pulse pressure waveform.

RESULTS

Carotid-radial PWV was lower in WBA than in RUN (P < .05), indicating higher arterial distensibility along the arm. Mean arterial pressure was lower in ATH than in CTR and in RUN than in WBA (P < .05). Synthesized aortic augmentation index (AI@75) was lower among ATH than among CTR (-12.8 ± 1.6 vs -2.6 ± 1.2%, P < .001) and in WBA than in RUN (-16.4 ± 2.5 vs -10.7 ± 2.0%, P < .05), suggesting a diminished return of reflection waves to the aorta during systole. Carotid-femoral PWV and intima-media thickness (IMT), lumen diameter and radial distensibility of the CCA were similar in ATH and CTR.

CONCLUSION

Elastic artery distensibility and carotid artery IMT are not different in young women with extensive endurance training over several years and in those with sedentary lifestyle. On the other hand, our data suggest that long-term endurance training is associated with potentially favourable peripheral artery adaptation, especially in sports where upper body work is added. This adaptation, if persisting later in life, could contribute to lower cardiovascular risk.

Time-Harmonic Ultrasound elastography of the Descending Abdominal Aorta: Initial Results

Stiffening of central large vessels is considered a key pathophysiologic factor within the cardiovascular system. Current diagnostic parameters such as pulse wave velocity (PWV) indirectly measure aortic stiffness, a hallmark of coronary diseases. The aim of the present study was to perform elastography of the proximal abdominal aorta based on externally induced time-harmonic shear waves. Experiments were performed in 30 healthy volunteers (25 young, 5 old, >50 y) and 5 patients with longstanding hypertension (PWV >10 m/s). B-Mode-guided sonographic time-harmonic elastography was used for measurement of externally induced shear waves at 30-Hz vibration frequency. Thirty-hertz shear wave amplitudes (SWAs) within the abdominal aorta were measured and displayed in real time and processed offline for differences in SWA between systole and diastole (ΔSWA). Data were analyzed using the Kruskal-Wallis test and receiver operating characteristic curve analysis. The change in SWA over the cardiac cycle was reduced significantly in all patients as assessed with ΔSWA (volunteers: mean = 10 ± 5 μm, patients: mean = 4 ± 1 μm; p < 0.001). The best separation of healthy volunteers from patients was obtained with a ΔSWA threshold of 4.7 μm, resulting in a sensitivity of 0.9 and a specificity of 1.0, with an overall area under the curve of 0.96. Time harmonic elastography of the abdominal aorta is feasible and shows promise for the exploitation of time-varying shear wave amplitudes as a diagnostic marker for aortic wall stiffening. Patients with elevated PWVs suggesting increased aortic wall stiffness were best identified by ΔSWA-a parameter that could be related to the ability of the vessel walls to distend on passages of the pulse wave.

Childhood Socioeconomic Status and Arterial Stiffness in Adulthood: The Cardiovascular Risk in Young Finns Study

Increasing evidence supports the importance of socioeconomic factors in the development of atherosclerotic cardiovascular disease. However, the association of childhood socioeconomic status (SES) with arterial stiffness in adulthood has not been reported. Our aim was to determine whether higher childhood family-level SES is associated with lower arterial stiffness in adulthood. The analyses were performed using data gathered within the longitudinal Young Finns Study. The sample comprised 2566 participants who had data concerning family SES at ages 3 to 18 years in 1980 and arterial pulse wave velocity and carotid artery distensibility measured 21 or 27 years later in adulthood. Higher family SES in childhood was associated with lower arterial stiffness in adulthood; carotid artery distensibility being higher (β value±SE, 0.029±0.0089%/10 mm Hg; P=0.001) and pulse wave velocity lower (β value±SE, -0.062±0.022 m/s; P=0.006) among those with higher family SES in a multivariable analysis adjusted with age, sex, and conventional childhood cardiometabolic risk factors. The association remained significant after further adjustment for participant's SES in adulthood (β value±SE, 0.026±0.010%/10 mm Hg; P=0.01 for carotid artery distensibility and β value±SE, -0.048±0.023 m/s; P=0.04 for pulse wave velocity) but attenuated after adjustment for adulthood cardiometabolic risk factors (β value±SE, 0.015±0.008%/10 mm Hg; P=0.08 for carotid artery distensibility and β value±SE, -0.019±0.02 m/s; P=0.38 for pulse wave velocity). In conclusion, we observed an association between higher family SES in childhood and lower arterial stiffness in adulthood. Our findings suggest that special attention could be paid to children from low SES families to prevent cardiometabolic diseases primordially.

Cardiometabolic Determinants of Carotid and Aortic Distensibility From Childhood to Early Adulthood

Children who are obese or have familial hypercholesterolemia have stiffer arteries compared with lean, healthy peers. Limited data are, however, available on the association of cardiometabolic risk markers and arterial distensibility in healthy children, particularly in a longitudinal setting. Therefore, we studied in the prospective STRIP (Special Turku Coronary Risk Factor Intervention Project) comprising healthy, predominantly normal weight participants the association of several cardiometabolic and dietary risk markers with arterial distensibility from childhood to early adulthood. Carotid and aortic distensibility (cdist, adist) was assessed repeatedly with ultrasonography at the age of 11, 13, 15, 17, and 19 years in the longitudinal atherosclerosis prevention study (n_cdist=420-503, n_adist=407-476). Data on cardiometabolic risk markers and diet were available since early childhood. In multivariable analyses, body mass index (β=-0.0019 [SE 0.0085]; P=0.037), systolic blood pressure (β=-0.0025 [SE 0.00065]; P=0.0001), low-density lipoprotein cholesterol (β=-0.026 [SE 0.012]; P=0.034), and homeostasis model of insulin resistance (β=-0.048 [SE 0.018]; P=0.0071) were independently associated with carotid distensibility. Systolic blood pressure (β=-0.0069 [SE 0.00097]; P<0.0001) and low-density lipoprotein cholesterol (β=-0.039 [SE 0.018]; P=0.031) associated independently with aortic distensibility. Dietary variables were not independently associated with arterial distensibility. Participants with low arterial distensibility had higher body mass index (P_cdist=0.0090, P_adist=0.098) and higher systolic (P_cdist<0.0001, P_adist<0.0001) and diastolic blood pressures (P_cdist<0.0001, P_adist=0.0002) already from early childhood. Body mass index, blood pressure, low-density lipoprotein cholesterol, and homeostasis model of insulin resistance identified since childhood associate with arterial distensibility in healthy children and adolescents. These data support the relevance of these factors as part of primordial prevention.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00223600.

Symmetric ambulatory arterial stiffness index in the young

The ambulatory arterial stiffness index (AASI) and the symmetric ambulatory arterial stiffness index (s-AASI) have been shown to correlate to arterial stiffness in adults. This study assesses these indices with anthropometric and blood pressure (BP) measures in children. A total of 102 children at a pediatric hypertension clinic who had ambulatory blood pressure monitoring (ABPM) done from 2009 to 2013 were included (75% males, 7-22yo, 47% hypertensive, 24% prehypertensive, and 34% white-coat hypertensives). AASI is 1 minus the regression slope of diastolic BP values on systolic BP values from a 24-hour ambulatory blood pressure monitoring. s-AASI is the symmetric regression of AASI. Obese patients had a significantly higher AASI. s-AASI correlated with systolic BP variability. In multivariable regression, BP variability independently correlated with AASI and s-AASI. s-AASI is related to systolic dipping.AASI and s-AASI are highly dependent on BP variability in children. Further studies are necessary to assess their utility.

Arterial Stiffness, Distensibility, and Strain in Asthmatic Children

BACKGROUND

We hypothesized that since asthma is a chronic inflammatory disease, it could lead to the early development of atherosclerosis in childhood-onset asthma. The aim of this study was to investigate arterial stiffness, distensibility, and strain of different peripheral arteries, the parameters of which can be used to detect atherosclerosis in asthmatic children.

MATERIAL/METHODS

We studied 22 pediatric patients with asthma and 18 healthy children. Fasting blood glucose and cholesterol levels were evaluated to exclude children with diabetes and hyperlipidemia, which are risk factors for atherosclerosis. Renal, carotid, and brachial arteries diameters were measured. Using the measured data, stiffness, distensibility, and strain of the arteries of all children were calculated.

RESULTS

Pulse pressure, systolic and diastolic blood pressure, heart rate, cholesterols, and glucose levels of the obese individuals were similar to the controls. In carotid arteries there were no statistical differences regarding stiffness, distensibility, and strain. According to multiple ANCOVA analysis, distensibility and strain of right and left brachial arteries and right renal artery were higher, whereas right renal artery stiffness was lower in asthmatic children than in controls. Approximately one-fifth of the change in the left and right brachial arteries and right renal artery distensibility and strain and a small portion of the change in the right renal artery stiffness were associated with asthma. In contrast, left renal artery distensibility, strain, and stiffness were not associated with asthma.

CONCLUSIONS

Peripheral arteries had higher distensibility and strain, and lower stiffness in asthmatic children than in controls.