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Background: In young athletes, exercise causes changes in the heart that include growth in wall thickness and mass of the left ventricle and expansion of the heart's chambers. The heart's function is either preserved or enhanced, but this may change to the opposite over time. Objective: This study aimed to assess structural and functional cardiac adaptations in relation to exercise training time, intensity, and performance in young competitive athletes. Methods: A total of 404 children and adolescents (14.23 ± 2.0 years, 97 females) were enrolled in the Munich Cardiovascular Adaptations in Young Athletes Study (MuCAYA-Study). Eighty-five participants were examined two times a year. Two-dimensional echocardiography was performed to assess left ventricular structure and function. Training time and intensity was measured with the MoMo physical activity questionnaire, maximum aerobic capacity by cardiopulmonary exercise testing, and strength with the handgrip strength test. Results: Maximum aerobic capacity significantly influenced interventricular septal thickness in diastole. Training intensity significantly influenced left ventricular internal diameter in diastole and systole, and left ventricular mass indexed to body surface area. Within one year, interventricular wall thickness, relative wall thickness and left ventricular mass, indexed to body surface area and height, increased significantly. Training intensity and aerobic capacity contributed to cardiac adaptations in young competitive athletes, as represented by altered structural parameters but preserved cardiac function. Within a year, however, structural changes and a decline in diastolic performance were observed within the longitudinal sub-sample. Conclusion: Our results confirm the hypothesis that cardiac adaptations to exercise occur at a young age. Cardiac adaptation in our cohort was influenced by exercise intensity and maximum aerobic capacity.
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OBJECTIVES: Grip strength is known to be reduced in adults with congenital heart disease (CHD). This study compared grip strength in paediatric patients with CHD with healthy controls and determined a possible association between grip strength and health-related physical fitness (HRPF). METHODS: Grip strength and HRPF were assessed in 569 children (12.4 years, 95% CI 12.16 to 12.72; 238 girls) with various CHD and compared with 2551 healthy controls (11.4 years, 95% CI 11.3 to 11.5; 1424 girls). Grip strength was determined as the maximum value of three repetitions with each hand. HRPF was tested by five motor tasks (FITNESSGRAM) and converted into an SD score (z-score). RESULTS: After adjusting for age, sex and weight, children with CHD showed significantly lower grip strength compared with healthy controls (CHD: 20.8 kg, 95% CI 20.4 to 21.2; controls: 24.5 kg, 95% CI 24.3 to 24.8). CHD subgroup analysis also revealed significantly lower grip strength than the controls, with the lowest values in patients with total cavopulmonary connection (19.1, 95% CI 18.0 to 20.2). Children with complex CHD showed the lowest values with 19.8 kg (95% CI 19.2 to 20.4), those with moderate 20.7 kg (95% CI 19.9 to 21.4) and those with simple 22.5 kg (95% CI 21.6 to 23.3), respectively. HRPF was also lower (z-score: -0.46, 95% CI -0.49 to -0.35) compared with healthy controls and poorly associated with grip strength (r=0.21). CONCLUSIONS: Grip strength is already reduced in children with CHD and poorly associated with HRPF. This suggests that grip strength and HRPF are different domains and have to be assessed separately.
Subject(s)
Hand Strength , Heart Defects, Congenital/physiopathology , Physical Fitness , Aortic Coarctation/complications , Aortic Valve Stenosis/complications , Child , Exercise , Female , Heart Defects, Congenital/complications , Humans , Male , Pulmonary Valve Stenosis/complications , Tetralogy of Fallot/complicationsABSTRACT
Background: In young athletes, the level of competitiveness in sports is increasing, as well as frequency and intensity of exercise training. Adaptations of the cardiac system to this increased workload imposed by exercise has not yet been studied sufficiently. In adults, studies point towards a shift from the functional athlete's heart towards pathological cardiac remodelling, with ventricular arrythmia and impaired cardiac function, that is exercise-related. This systematic review investigates cardiac adaptations to exercise in junior athletes compared to inactive controls. Methods: Three electronic databases (PubMed/Medline, ScienceDirect and Web of Science) were searched for studies assessing 2-dimensional transthoracic echocardiography (2D TTE) and 2-dimensional speckle tracking echocardiography (2D STE) parameters in junior athletes, aged 7-19 years, compared to inactive controls. Data was screened and extracted by two reviewers; study quality and risk of bias was assessed by three reviewers. Results: Eight out of 1460 studies met all inclusion criteria, with all studies reporting results on 2D TTE and six studies reporting results on 2D STE parameters in 540 (51 girls) junior athletes and 270 (18 girls) controls. There is evidence for structural cardiac adaptations of the left ventricle and both atria in junior athletes. Results regarding left ventricular function are controversial with a tendency to improved function in dynamic exercising athletes. Left ventricular mass and relative wall thickness point towards higher values in static exercising athletes. Conclusions: Cardiac adaptations to exercise occur in children and adolescents. These adaptations are more pronounced in structural left ventricular parameters. Functional parameters are preserved or slightly improved in junior athletes but not impaired by exercise.
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Even though exercise generally has a positive effect on health, intensive exercise can have adverse effects on the vascular system of adults. This study aimed to investigate the association between training duration and intensity and vascular structure and function in 427 physically active children and adolescents (14.0 ± 1.94 years). In this study, we examined carotid intima-media thickness (cIMT), carotid diameter, and cIMT:diameter-ratio as parameters of carotid arterial structure and arterial compliance (AC), stiffness index ß (ß), elastic modulus (Ep), and carotid pulse wave velocity (PWVß) as parameters of carotid arterial function with high-resolution ultrasound. We collected central systolic blood pressure (cSBP) and aortic pulse wave velocity (aPWV) as parameters of central arterial stiffness with an oscillometric device. We used the MoMo Physical Activity Questionnaire to record training duration and intensity. Training duration (p = 0.022) and intensity (p = 0.024) were associated with higher cIMT. Further, training duration was associated with lower central arterial stiffness (cSBP: p = 0.001; aPWV: p = 0.033) and improved AC (p < 0.001). Higher training intensity was related to improved AC (p < 0.001) and larger carotid diameter (p = 0.040). Boys presented thicker cIMT (p = 0.010), improved AC (p = 0.006), and lower central arterial stiffness (cSBP: p < 0.001; aPWV: p = 0.016) associated with higher training duration. Girls presented improved AC (p = 0.023) and lower Ep (p = 0.038) but higher ß (p = 0.036) associated with higher training duration. Only boys demonstrated thicker cIMT (p = 0.016) and improved AC (p = 0.002) associated with higher training intensity. A quintile analyses of the training duration revealed thicker cIMT of children and adolescents in Q1 and Q5 than that in Q4 and Q5. Besides, Q1 showed lower cSBP compared to Q4 and Q5. Regarding training intensity, Q5 had thicker cIMT than Q2 and Q3. Although a higher training load is associated with thicker cIMT, the common carotid artery is also more elastic. This suggests that a higher training load leads to a functional adaptation of the carotid artery in youth.
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Young athletes most often exceed the physical activity recommendations of the World Health Organization. Therefore, they are of special interest for investigating cardiovascular adaptions to exercise. This study aimed to examine the arterial structure and function of young athletes 12-17 years old and compare these parameters to reference values of healthy cohorts. Carotid intima-media thickness (cIMT), carotid diameter, cIMT÷carotid diameter-ratio (cIDR), arterial compliance (AC), elastic modulus (Ep), ß stiffness index (ß), and carotid pulse wave velocity (PWVß) were determined using ultrasound in 331 young athletes (77 girls; mean age, 14.6 ± 1.30 years). Central systolic blood pressure (cSBP) and aortic PWV (aPWV) were measured using the oscillometric device Mobil-O-Graph. Standard deviation scores (SDS) of all parameters were calculated according to German reference values. The 75th and 90th percentiles were defined as the threshold for elevated cIMT and arterial stiffness, respectively. Activity behavior was assessed with the MoMo physical activity questionnaire, and maximum power output with a standard cardiopulmonary exercise test. One-sample t-tests were performed to investigate the significant deviations in SDS values compared to the value "0". All subjects participated in competitive sports for at least 6 h per week (565.6 ± 206.0 min/week). Of the 331 young athletes, 135 (40.2%) had cIMT >75th percentile, 71 (21.5%) had cSBP >90th percentile, and 94 (28.4%) had aPWV>90th percentile. We observed higher cIMT SDS (p < 0.001), cIDR SDS (p = 0.009), and AC SDS (p < 0.001) but lower ß SDS (p < 0.001), Ep SDS (p < 0.001), and PWVß SDS (p < 0.001) compared to the reference cohort. The cSBP SDS (p < 0.001) and aPWV SDS (p < 0.001) were elevated. In conclusion, cIMT and cIDR were higher in young athletes than in a reference cohort. Furthermore, young athletes presented better carotid elasticity and lower arterial stiffness of the carotid artery. However, central arterial stiffness was higher compared to the reference cohort. The thickening of the carotid intima-media complex in combination with a reduction in arterial stiffness indicates a physiological adaptation to exercise in youth.
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In children, arterial alterations occur with increased intima-media thickness as well as vascular diameter enlargement. Both conditions correlate with higher cardiovascular risk in adults, and both the array and proportion of these alterations are important hemodynamic parameters. In terms of functional adaptation processes, they influence several arterial wall properties as for example the shear and tensile stress of the vessel. There are no reference values for the vascular diameter and intima-media thickness/diameter ratio of the carotid artery in children. Therefore, this study aimed to assess vascular diameter, intima-media thickness/diameter ratio and related tensile stress values in children and to further investigate the influence of sex, age, body mass index, and blood pressure. The parameters were measured with high-resolution semi-automated ultrasound. Sex- and age-dependent values were calculated with the LMS method for a cross-sectional sample of 642 healthy, non-obese children aged 8-17 years. The mean vascular diameter was 5.45 ± 0.46 mm; the median intima-media thickness/diameter ratio was 0.085 (0.079-0.092); the median tensile stress was 105.4 (95.2-116.4) kPa. The vascular diameter and the tensile stress were higher, and the intima-media thickness/diameter ratio was lower in boys than in girls. In comparison to the normal weight study population the excludedobese children had a significantly higher diameter, a lower intima-media thickness/diameter ratio, and a higher tensile stress. In multiple regression analyses of diameter, intima-media thickness/diameter ratio, and tensile stress, all parameters were influenced by sex and body mass index. Furthermore, systolic and diastolic blood pressure significantly influenced the vascular diameter, and systolic blood pressure significantly influenced the intima-media thickness/diameter ratio. Conclusion: This study is the first to report values for the diameter, the intima-media thickness/diameter ratio of the carotid artery, and the related tensile stress allowing a more differentiated view of cardiovascular adaptations as it combines structural and functional vascular parameters. What is known: ⢠Intima-media thickness and vascular diameter are related to a higher cardiovascular risk in adults ⢠The intima-media thickness/diameter ratio gives information about hemodynamic and functional vessel adaptation What is new: ⢠Values for vascular diameter, intima-media thickness/diameter ratio, and tensile stress of the carotid artery in children are presented in this study ⢠Intima-media thickness as a surrogate marker for arterial health in children should be complemented by intima-media thickness/diameter ratio measurement.
Subject(s)
Carotid Arteries , Carotid Intima-Media Thickness , Adolescent , Adult , Blood Pressure , Body Mass Index , Carotid Arteries/diagnostic imaging , Child , Cross-Sectional Studies , Female , Humans , Male , Risk FactorsABSTRACT
A physically active lifestyle can prevent cardiovascular disease. Exercise intervention studies in children and adolescents that aim to increase physical activity have resulted in reduced vascular wall thickening and improve cardiovascular function. Here we review the literature that explores the correlations between physical activity, health-related physical fitness, and exercise interventions with various measures of vascular structure and function in children and adolescents. While several of these studies identified improvements in vascular structure in response to physical activity, these associations were limited to studies that relied on questionnaires. Of concern, these findings were not replicated in studies featuring quantitative assessment of physical activity with accelerometers. Half of the studies reviewed reported improved vascular function with increased physical activity, with the type of vascular measurement and the way physical activity was assessed having an influence on the reported relationships. Similary, most of the studies identified in the literature report a beneficial association of health-related physical fitness with vascular structure and function. Overall, it was difficult to compare the results of these studies to one another as different methodologies were used to measure both, health-related physical fitness and vascular function. Likewise, exercise interventions may reduce both arterial wall thickness and increased vascular stiffness in pediatric populations at risk, but the impact clearly depends on the duration of the intervention and varies depending on the target groups. We identified only one study that examined vascular structure and function in young athletes, a group of particular interest with respect to understanding of cardiovascular adaptation to exercise. In conclusion, future studies will be needed that address the use of wall:diameter or wall:lumen-ratio as part of the evaluation of arterial wall thickness. Furthermore, it will be critical to introduce specific and quantitative measurements of physical activity, as intensity and duration of participation likely influence the effectiveness of exercise interventions.
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Objective: Moderate physical activity (PA) is associated with a reduced risk to develop cardiovascular disease. However, junior athletes exercise between 10 and 20 h a week with intensities exceeding moderate levels by far. In this regard, the cardiovascular system has to increase its work five to six times compared to moderate intensities. This may result in potentially pathological adaptations of the cardiovascular system. The underlying process of vascular adaptations to exercise is yet not fully understood and hardly investigated in junior athletes. An increased blood pressure and pulse wave velocity, ventricular hypertrophy, arrhythmia, and even sudden cardiac death (SCD) has been reported in adult athletes. Studies, examining the cardiovascular system in children, its association to intensity and type of exercise, are rare. Therefore, we present the study protocol of a prospective cross-sectional study that investigates the influence of PA on the cardiovascular system in young athletes. Methods and Design: Children and adolescents, 7-18 years, presenting for their annual pre-participation screening at the Institute of Preventive Pediatrics, Faculty of Sports and Health Sciences, Technical University of Munich (TUM), are examined in this prospective cross-sectional study. Vascular parameters measured by ultrasound are carotid intima-media thickness (cIMT), vascular stiffness (AC, Ep, ß, PWV ß), and the vascular diameter (D) to calculate the IMT:Diameter-Ratio (IDR). Cardiac function is evaluated by a 12-lead ECG, and echocardiographic parameters (end-diastolic left ventricular diameter, left ventricular diastolic posterior wall thickness, diastolic septal thickness, left ventricular mass and relative wall thickness, ejection fraction, and shortening fraction). A cardiopulmonary exercise test is performed on a bicycle ergometer, muscular strength is assessed with the handgrip test, and physical activity with the MoMo questionnaire. Discussion: It is essential to follow young athletes over the course of their career in order to detect pathophysiological changes in the myocardium as soon as possible. If these changes are preceded or followed by changes in vascular structure and function is not known yet. Therefore, we present the study protocol of the Munich Cardiovascular adaptations in young athletes study (MuCAYA-Study) which investigates the association between vascular and cardiac adaptation to intensive exercise in junior athletes.
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Vascular alterations may lead to manifest cardiovascular disease in future life. There is a tremendous time delay between the onset and obvious clinical appearance of vascular alterations. Pulse wave velocity (PWV) is one subclinical parameter to detect vascular alterations at a very early stage. Different techniques exist to measure PWV non-invasively as a vascular parameter-all with their own technique-inherent advantages, challenges, and pitfalls. The aim of this study was to compare two techniques to measure PWV, to assess their agreement, and interchangeability. In 780 (â = 49.4%) healthy children and adolescents (mean age: 11.61 ± 2.11 years), PWV was obtained with two different techniques. Ultrasound-measured local PWV (PWVß) at the carotid artery was graphically compared by a Bland-Altman plot with aortic PWV (aPWV), measured oscillometrically on the brachial artery. Reproducibility was assessed with the concordance correlation coefficient by Lin (ρc). Furthermore, participants were categorized by BMI as normal weight (N) or overweight/obese (O) to identify differences in PWVß and aPWV caused by an increased BMI. Mean PWVß was lower (4.01 ± 0.44 m/s) than mean aPWV (4.67 ± 0.34 m/s). The two methods differ by mean Δ0.66 ± 0.47 m/s (95% CI: 0.62 to 0.69 m/s; p < 0.001). Bland-Altman analysis indicated the 95% limits of agreement (-0.26 to 1.57) without any evidence of systemic difference. Lin's ρc represented a weak concordance between PWVß and aPWV (ρc = 0.122; 95% CI: 0.093-0.150). There was no difference in PWVß between N and O, whereas aPWV was higher in O: 4.81 ± 0.42 m/s than in N: 4.65 ± 0.32 m/s (p < 0.001). The difference, Δ0.16 m/s, 95% CI [-0.25; -0.08], was significant, t (121) = -3.76, p < 0.001, with a medium-sized effect. PWVß (ultrasound) and aPWV (oscillometry) show a level of disagreement that includes clinically important discrepancies. A discrimination between normal and altered vascular function was possible with aPWV but not with PWVß.
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BACKGROUND: This study investigated the effect of a six-week in-season core stability training (CST) intervention on maximal throwing velocity and core strength parameters. METHODS: Twenty female handball players (23.4±4.4 years, 168.4±3.5 cm, and 66.9±9.2 kg) were randomized into a CST intervention group (N.=10) and a control group (CON, N.=10). Throwing velocity, maximal isometric strength (MIS) and endurance strength of the ventral, dorsal and lateral core muscle chains were measured before and after progressive, six-week core stability training in the CST group. RESULTS: Core endurance of both lateral core muscle chains (LR: F=7.03, P=0.017; LL: F=6.31, P=0.022;) and MIS of the left lateral core muscle chain (LL: F=7.08, P=0.019) was significantly improved in CST compared to CON group after 6 weeks. Additionally, CST group significantly increased MIS of the lateral right core muscles (21%, P=0.042) and the ventral core endurance (35%, P=0.016) compared to baseline. Although both groups significantly increased throwing velocity of the jump throw after the intervention (CST 12%, P=0.001; CON 8%, P=0.009), throwing velocity of the standing throw remained unchanged. CONCLUSIONS: A six-week CST intervention effectively increased the isometric strength and endurance of selected core muscles but did not significantly enhance throwing velocity compared to standard training.
Subject(s)
Exercise Test/methods , Muscle Strength/physiology , Physical Endurance/physiology , Racquet Sports/physiology , Adult , Exercise/physiology , Female , Humans , Young AdultABSTRACT
OBJECTIVE: The body's adaptation to physical exercise is modulated by sympathetic and parasympathetic (vagal) branches of the autonomic nervous system (ANS). Heart rate variability (HRV), the beat-to-beat variation of the heart, is a proxy measure for ANS activity, whereas blood pressure (BP) is an indicator for cardiovascular function. Impaired vagal activity and lower BP is already described after exercise. However, inconsistent results exist about how long vagal recovery takes and how long post-exercise hypotension persists. Therefore, the aim of this study was to assess HRV and BP 1 h after maximal cardiopulmonary exercise testing (CPET). PATIENTS AND METHODS: HRV (Polar RS800CX), peripheral and central BP (Mobil-O-Graph®) were prospectively studied in 107 healthy volunteers (47 female, median age 29.0 years) in supine position, before and 60 min after maximal CPET. RESULTS: One hour after terminating CPET measures of HRV were still impaired and post-exercise BP was significantly reduced suggesting an improved vascular function compared to pre levels. HRV parameters post-exercise were 34.7% (RMSSD), 67.2% (pNN50), 57.2% (HF), and 42.7% (LF) lower compared to pre-exercise levels (for all p < 0.001). Median reduction in BP was 5 mmHg for systolic BP (p < 0.001), and 4 mmHg for diastolic BP (p = 0.016) and central systolic post-exercise (p = 0.005). CONCLUSIONS: One hour after terminating strenuous exercise, autonomic nervous regulation seems to be postponed which is reflected in reduced HRV, whereas the early recovery of the vasculature, post-exercise hypotension, is still preserved over the recovery period of 1 h.
Subject(s)
Heart/physiology , Physical Conditioning, Human/physiology , Post-Exercise Hypotension/physiopathology , Recovery of Function , Vagus Nerve/physiology , Adaptation, Physiological , Blood Pressure , Cardiorespiratory Fitness , Coronary Vessels/innervation , Coronary Vessels/physiology , Exercise Test/methods , Exercise Test/standards , Female , Heart/innervation , Humans , Male , Physical Conditioning, Human/adverse effects , Post-Exercise Hypotension/etiologyABSTRACT
Low cardiorespiratory fitness is associated with higher cardiovascular risk, whereas high levels of cardiorespiratory fitness protect the cardiovascular system. Carotid intima-media thickness and arterial distensibility are well-established parameters to identify subclinical cardiovascular disease. Therefore, this study investigated the influence of cardiorespiratory fitness and muscular strength on carotid intima-media thickness and arterial distensibility in 697 children and adolescents (376 girls), aged 7-17 years. Cardiorespiratory fitness and strength were measured with the test battery FITNESSGRAM; carotid intima-media thickness, arterial compliance, elastic modulus, stiffness index ß, and pulse wave velocity ß were assessed by B- and M-mode ultrasound at the common carotid artery. In bivariate correlation, cardiorespiratory fitness was significantly associated with all cardiovascular parameters and was an independent predictor in multivariate regression analysis. No significant associations were obtained for muscular strength. In a one-way variance analysis, very fit boys and girls (58 boys and 74 girls>80th percentile for cardiorespiratory fitness) had significantly decreased stiffness parameters (expressed in standard deviation scores) compared with low fit subjects (71 boys and 77 girls<20th percentile for cardiorespiratory fitness): elastic modulus -0.16±1.02 versus 0.19±1.17, p=0.009; stiffness index ß -0.15±1.08 versus 0.16±1.1, p=0.03; and pulse wave velocity ß -0.19±1.02 versus 0.19±1.14, p=0.005. Cardiorespiratory fitness was associated with healthier arteries in children and adolescents. Comparison of very fit with unfit subjects revealed better distensibility parameters in very fit boys and girls.
Subject(s)
Blood Pressure/physiology , Cardiovascular Diseases/epidemiology , Carotid Arteries/physiopathology , Physical Fitness/physiology , Vascular Resistance , Vascular Stiffness/physiology , Adolescent , Cardiovascular Diseases/diagnosis , Cardiovascular Diseases/prevention & control , Carotid Arteries/diagnostic imaging , Carotid Intima-Media Thickness , Child , Cross-Sectional Studies , Female , Follow-Up Studies , Germany/epidemiology , Humans , Incidence , Male , Prospective Studies , Risk Factors , UltrasonographyABSTRACT
BACKGROUND AND AIMS: Subclinical atherosclerosis assessed by sonographic intima-media-thickness measurement of the carotid artery (cIMT) is considered to be an early precursor of cardiovascular disease already in childhood. Structural analysis of the carotid intimal layer (carotid intima-media-roughness, cIMR) improves cardiovascular risk profiling for the adult patient and has been shown to be increased also in paediatric patients with elevated cardiovascular risk. To date, normal values for the paediatric age are lacking. Thus, we present normative data for a paediatric age group. METHODS: 602 healthy German school children (age 8-18 y) were studied, and cIMT and cIMR calculated; reference values were given for three age groups (group 1: 8-10.99 years; group 2: 11-13.99 years; group 3: 14-17.99 years). RESULTS: cIMT values were: 0.48 ± 0.03 mm for girls and boys in age group 1, 0.49 ± 0.03 mm for girls and boys in age group 2; and 0.45 ± 0.03 mm for girls and 0.49 ± 0.03 mm for boys in age group 3; cIMR was 0.04 ± 0.01 mm for both sexes in age group 1 and 3; while in age group 2, both sexes showed a cIMR of 0.03 ± 0.01 mm. Physical fitness was significantly negatively correlated with cIMR (r = - 0.212, p < 0.0001) and a strong predictor for cIMR increase. CONCLUSIONS: The normative data of cIMR for a paediatric age group presented here allow for the identification of patients at elevated cardiovascular risk. By including cIMR as surface analysis of the arterial wall, the individual risk stratification may be improved compared to thickness-analysis of the Intima-Media-Layer (cIMT) also at a paediatric age.
Subject(s)
Carotid Artery, Common/pathology , Carotid Intima-Media Thickness , Adolescent , Cardiology/standards , Carotid Artery, Common/diagnostic imaging , Child , Cohort Studies , Cross-Sectional Studies , Disease Progression , Female , Germany , Healthy Volunteers , Humans , Male , Reference Values , Risk Assessment , Risk Factors , UltrasonographyABSTRACT
Carotid intima-media thickness (cIMT) is a surrogate marker of early atherosclerotic changes in children. cIMT-studies are hard to compare, due to variations in ultrasound protocols, especially regarding the common carotid artery (CCA) segment measured in relation to the bulb. This study's purpose was therefore to compare two distinct CCA segments in children, to see if cIMT values differ substantially according to the site of measurement. cIMT was assessed after power calculation in 30 children (15 girls) aged 8-17, using B-Mode ultrasound (5-13 MHz) at two CCA locations. The first measurement was performed over a distance of 1 cm immediately after the bulb (A), the second 1cm proximal the bulb (B) over the same distance of 1cm length. Means of end-diastolic far wall cIMT were compared between measurement A and B. cIMT in 30 participants was 0.51±0.06 mm for measurement A and 0.51±0.05 mm for measurement B. Results did not differ significantly (p = .947) over a distance of 2 cm after the bulb. According to our results, studies measuring CCA IMT within the first 2 cm, either close to the bulb or further proximal, can be compared. This will improve interpretation of data and application of reference values.
Subject(s)
Carotid Artery, Common/diagnostic imaging , Carotid Intima-Media Thickness , Adolescent , Child , Female , Humans , MaleABSTRACT
OBJECTIVE: Subclinical atherosclerosis can be assessed via sonographic measurement of intima-media thickness and carotid artery distensibility, both may already be pathologically altered in childhood. Therefore, the purpose of this study was to provide reference percentiles and investigate possible associations between alterations of intima-media thickness and distensibility. METHODS: Carotid intima-media thickness and distensibility was measured via B- and M-mode ultrasound. Distensibility was defined by arterial compliance, elastic modulus, stiffness parameter ß, and local pulse wave velocity ß. Age- and height-dependent reference values were calculated separately for boys and girls among 690 (intima-media thickness) and 870 (distensibility) non-obese children aged 7-17 years. RESULTS: Intima-media thickness and distensibility did not increase significantly with age or differ between boys and girls. Systolic blood pressure and body mass index were independent predictors of intima-media thickness, while an increased systolic blood pressure or pulse pressure was associated with stiffer arteries. Increased intima-media thickness was accompanied by higher arterial compliance and lower stiffness. CONCLUSION: Using this healthy cohort, we describe a functional and non-pathological arterial adaptation wherein an increase in intima-media thickness is not associated with stiffer arteries.
Subject(s)
Aging/physiology , Carotid Intima-Media Thickness , Vascular Stiffness , Adaptation, Physiological , Adolescent , Atherosclerosis/diagnostic imaging , Blood Pressure , Body Height , Body Mass Index , Child , Compliance , Diagnosis, Differential , Electrocardiography , Female , Humans , Male , Prospective Studies , Pulse Wave Analysis , Reference ValuesABSTRACT
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 ß (ß), and local pulse wave velocity ß (PWV ß). RESULTS: Obese girls had significantly stiffer arteries compared with normal weight girls (Ep SDS 0.64 ± 1.24 vs. 0 ± 1.06, ß SDS 0.6 ± 1.17 vs. -0.01 ± 1.06 p < .01, PWV ß 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, ß and PWV ß 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, ß and PWV ß) but not compliance or cIMT.