Intima-media thickness measurements in children with cardiovascular risk factors

Lean body mass may explain apparent racial differences in carotid intima-media thickness in obese children

BACKGROUND

Racial differences in carotid intima-media thickness (cIMT) have been suggested to be associated with the disproportionally high prevalence of cardiovascular disease in black adults. The objective of this study was to evaluate the effects of cardiovascular risk factors on the racial differences seen in cIMT in obese children.

METHODS

Obese subjects aged 4 to 21 years were recruited prospectively. Height, weight, blood pressure, fasting insulin, glucose, lipid panel, high-sensitivity C-reactive protein, and body composition by dual-energy x-ray absorptiometry were obtained. B-mode carotid imaging was analyzed by a single blinded physician.

RESULTS

A total of 120 subjects (46 white, 74 black) were enrolled. Black subjects exhibited greater cIMT (0.45 ± 0.03 vs 0.43 ± 0.02 cm, P < .01) and higher lean body mass index (19.3 ± 3.4 vs 17.3 ± 3.2 kg/m², P = .02) than white subjects. Simple linear regression revealed modest associations between mean cIMT and race (R = 0.52, P < .01), systolic blood pressure (R = 0.47, P < .01), and lean body mass (R = 0.51, P < .01). On multivariate regression analysis, lean body mass remained the only measure to maintain a statistically significant relationship with mean cIMT (P < .01).

CONCLUSIONS

Black subjects demonstrated greater cIMT than white subjects. The relationship between race and cIMT disappeared when lean body mass was accounted for. Future studies assessing the association of cardiovascular disease risk factors to cIMT in obese children should include lean body mass in the analysis.

Serum fetuin A concentration is elevated in children with non-alcoholic fatty liver disease

PURPOSE

To assess the serum fetuin A concentration as a potential marker of subclinical atherosclerosis in obese children with NAFLD.

MATERIAL/METHODS

A prospective analysis of 45 obese children initially diagnosed with liver pathology (elevated serum ALT activity and/or ultrasonographic liver brightness and/or hepatomegaly) was conducted. The diagnosis of NAFLD was established in the children with elevated serum ALT activity and liver steatosis on ultrasound examination. Viral hepatitis, autoimmune, metabolic liver diseases (Wilson disease, alpha-1-antitrypsin deficiency, cystic fibrosis) and drug and toxin-induced liver injury were excluded in all children. The degree of liver steatosis was graded according to Saverymuttu scale and the total liver lipids concentration was assessed using proton magnetic resonance spectroscopy ((1)H MRS).

RESULTS

Serum fetuin A concentration was significantly higher in examined children compared to the control group (n=30) (p=0.00002). Higher serum fetuin A concentration was also observed in children with NAFLD (n=19) in comparison to the controls (p=0.000026). Additionally, higher BMI values, waist circumferences, ALT and GGT activity, intensity of liver steatosis on ultrasound and total concentration of lipids in the liver in (1)H MRS were found in children with NAFLD compared to the rest of the examined obese patients (n=26). There was not found any correlation of the investigated glycoprotein with any other assessed parameters both in children with NAFLD and obese children without NAFLD.

CONCLUSION

Higher serum fetuin A concentration found in children with NAFLD compared to the control group support the hypothesis that atherosclerotic processes may develop faster in hepatopatic obese patients.

Subclinical cardiovascular disease and its association with risk factors in children with steroid-resistant nephrotic syndrome

BACKGROUND

The aim of this study was to evaluate the presence of subclinical cardiovascular disease (CVD) and its relation to risk factors in pediatric patients with steroid-resistant nephrotic syndrome (NS).

METHODS

Thirty-seven patients with normal renal function were compared with 22 healthy controls regarding the presence of subclinical CVD. Measurements included aortic pulse wave velocity (PWV), carotid intima media thickness (IMT), and left ventricular mass (LVM). Patients were additionally assessed for blood pressure (BP) pattern and the presence of hypertension by 24-h ambulatory blood pressure monitoring.

RESULTS

Compared with the controls, patients had significantly higher mean aortic PWV-standard deviation scores (SDS), mean carotid IMT-SDS, and LVM index (p < 0.001 for all). Increased aortic PWV was noted in 5 % of patients, increased carotid IMT in 22 %, and increased LVM index in 19 %. Five patients (14 %) were hypertensive, and mean BP indexes, SDS, and BP loads during nighttime were significantly higher than those during daytime (p < 0.001 for all). Multivariate analysis revealed a significant relationship between PWV-SDS and ferritin (R(2) = 0.269, p = 0.006) and between carotid IMT-SDS and proteinuria (R(2) = 0.141, p = 0.022). The LVM index was independently associated only with higher body mass index SDS (R(2) = 0.317, p < 0.001). In addition, six patients (16 %) had multiple abnormal subclinical CVD markers, and increased subclinical CVD risk was independently associated only with higher low-density lipoprotein cholesterol (R(2) = 0.292, p = 0.044).

CONCLUSIONS

Based on these results, steroid-resistant NS children generally are at high risk of cardiovascular complications, but the increased risk is likely to be multifactorial.

Cardiovascular changes in children with coarctation of the aorta treated by endovascular stenting

The aim of this study was to investigate the echocardiographic, biochemical short- and mid-term effects of the stenting procedure on left ventricular function, aortic stiffness, elasticity and systemic hypertension in children with coarctation of the aorta (CoA). Fifteen patients with native or recurrent CoA and 30 healthy controls who were sex and age matched were included in the study. The blood pressure values, echocardiographic measurements, elastic functions of ascending aorta and serum N-Terminal ProBNP (NT-ProBNP) levels were recorded prospectively before and at the first and sixth month after stenting. The mean arterial pressure recorded before stenting was 134.4±16.3 mm Hg; at the sixth month it was 115.5±9.5 mm Hg and in the control group it was 107.3±9.4 mm Hg. Although blood pressure levels were lower compared with the pre-stenting measurements (P<0.05), they were still significantly higher compared with the control group (P<0.05). Although a significant reduction was detected in the LVMIz at the end of the sixth month (50.4±14.3 g m(-2.7)) compared with the baseline (66.6±17.9 g m(-2.7); P<0.05), it was still higher compared with the control group (35.7±6.2 g m(-2.7); P<0.05). The baseline aortic elasticity (6.4±3.4 cm(2) dyn(-1) 10(-6)) was lower compared with the control group (10.0±1.7 cm(2) dyn(-1) 10(-6); P<0.05), and prestenting aortic stiffness was higher than that of the control group (5.6±1.6 dyn(-1) 10(-6); 2.5±0.45  dyn(-1) 10(-6); P<0.05). A statistically significant negative correlation was detected between the pressure gradient at the lesion site and aortic elasticity (r: -0.53, P: 0.04). Although resolution of the coarctation by endovascular stenting led to a reduction in the arteriopathy that had already begun before treatment, it was demonstrated that these children did not completely return to normal.

Cardiac function and arterial biophysical properties in small for gestational age infants: postnatal manifestations of fetal programming

OBJECTIVE

To investigate the differences in cardiac function and arterial biophysical properties between term-born appropriate for gestational age (AGA) infants and small for gestational age (SGA) infants. Our hypothesis was that adaptation to intrauterine growth restriction induces changes in cardiac and arterial indices.

STUDY DESIGN

This was a prospective observational echocardiographic evaluation of cardiac and arterial indices in SGA infants and AGA infants. Demographic and echocardiographic data were compared between 20 inborn term SGA infants with birth weight <3rd percentile for gestational age and 20 AGA infants.

RESULTS

The Ponderal index was significantly lower and blood pressure was significantly higher in the SGA infants compared with the AGA infants. Left ventricular output was lower in the SGA infants (170 ± 31 mL/kg/min vs 197 ± 39 mL/kg/min). Diastolic dysfunction was greater in the SGA infants (ie, reduced E and A wave velocities, higher E/A ratio [1.08 ± 0.16 vs 0.85 ± 0.07], and prolonged isovolumic relaxation time [73 ± 6.2 ms vs 62.6 ± 3.6 ms]). Aortic intima-media thickness was significantly greater in the SGA infants (822 ± 105 μm vs 694 ± 52 μm), as were arterial wall stiffness index and input impedance.

CONCLUSION

Cardiac function and arterial biophysical properties were altered in the SGA infants. The findings complement the information on the association between in utero growth and cardiovascular morbidity in later life.

Is autoimmune thyroiditis a risk factor for early atherosclerosis in premenopausal women even if in euthyroid status?

Autoimmune thyroiditis (AIT) is a systemic disease. It is well-known that overt thyroid dysfunction is a cardiovascular risk factor. However, the influence of euthyroid status is unclear. The aim of this study was to evaluate the metabolic parameters and carotid intima-media thickness (CIMT) in euthyroid premenopausal women with AIT. Fourty-eight premenopausal women and 18 age-matched healthy controls attending the Endocrinology and Metabolism Clinic from 2008 to 2009 were enrolled to this cross-sectional study. Patients were divided into 2 groups according to TSH levels; patients in group 1 (n = 23) had TSH levels ≤ 2.5 μIU/mL and patients in group 2 had TSH levels > 2.5 μIU/mL (n = 25). All participants were evaluated by ultrasound for CIMT (mean of three segments in both carotid arteries) by the same experienced investigator. Fasting venous blood samples were collected to evaluate insulin resistance (HOMA-IR), TSH, FT4, plasma lipids, high-sensitive CRP (Hs-CRP), homocysteine, and fibrinogen. Carotid intima-media thickness was found to be significantly higher in patients than the controls (p < 0.001). However, there was no significant difference in average CIMT between group 1 and 2 (0.66 ± 0.08 vs 0.63 ± 0.09 mm). Anti-Tg levels were independently associated with CIMT in the patient group (p = 0.014). There were no significant correlations between serum TSH levels and BMI; waist circumference, serum lipids, and glucose levels. However, there was a positive significant correlation between TSH levels and blood pressure in the patients (for systolic blood pressure r = 0.466, p = 0.001, for diastolic blood pressure r = 0.372, p = 0.009). In the present study, it was shown that CIMT is increased in euthyroid premenopausal women with autoimmune thyroiditis compared to age-matched healthy controls.

Carotid artery intima-media thickness and distensibility in children and adolescents: reference values and role of body dimensions

Carotid intima-media thickness (cIMT) and carotid artery distensibility are reliable screening methods for vascular alterations and the assessment of cardiovascular risk in adult and pediatric cohorts. We sought to establish an international reference data set for the childhood and adolescence period and explore the impact of developmental changes in body dimensions and blood pressure (BP) on carotid wall thickness and elasticity. cIMT, the distensibility coefficient, the incremental modulus of elasticity, and the stiffness index β were assessed in 1155 children aged 6 to 18 years and sex-specific reference charts normalized to age or height were constructed from 1051 nonobese and nonhypertensive children. The role of body dimensions, BP, and family history, as well as the association between cIMT and distensibility, was investigated. cIMT increased and distensibility decreased with age, height, body mass index, and BP. A significant sex difference was apparent from the age of 15 years. Age- and height-normalized cIMT and distensibility values differed in children who are short or tall for their age. By stepwise multivariate analysis, standardized systolic BP and body mass index were independently positively associated with cIMT SD scores (SDS). Systolic BP SDS independently predicted all distensibility measures. Distensibility coefficient SDS was negatively and β SDS positively associated with cIMT SDS, whereas incremental modulus of elasticity was independent of cIMT. Morphological and functional aspects of the common carotid artery are particularly influenced by age, body dimensions, and BP. The reference charts established in this study allow to accurately compare vascular phenotypes of children with chronic conditions with those of healthy children.

Subclinical hypothyroidism as a risk factor for the development of cardiovascular disease in obese adolescents with nonalcoholic fatty liver disease

No data are available on the relationship between subclinical hypothyroidism and risk factors for the development of cardiovascular disease in obese adolescents with nonalcoholic fatty liver disease (NAFLD). This study aimed to determine whether an association exists between subclinical hypothyroidism and risk factors for the development of cardiovascular disease in obese adolescents with NAFLD. The study enrolled 111 obese adolescents and 42 lean subjects. The obese subjects were divided into two subgroups based on the presence or absence of fatty liver with high transaminases: a NAFLD group and a non-NAFLD group. Subclinical hypothyroidism was defined as a thyroid-stimulating hormone (TSH) level higher than 4 mIU/l and a normal free-thyroxine level (0.6-1.8 ng/dl). Insulin resistance was calculated by the homeostasis model assessment (HOMA-IR). Left ventricular mass (LVM), LVM index measurements, carotid intima media thickness (IMT), and HOMA-IR values were higher in the NAFLD obese group with TSH levels higher than 4 mIU/l than in the NAFLD obese group with TSH levels lower than 4 mIU/l. Elevated TSH values in the NAFLD obese group were positively correlated with most of the metabolic and cardiovascular risk parameters such as total cholesterol (r = 0.606, p = 0.001), triglycerides (r = 0.476, p = 0.016), low-density lipoprotein cholesterol (r = 0.461, p = 0.004), insulin (r = 0.607, p = 0.001), HOMA-IR (r = 0.596, p = 0.002), carotid IMT (r = 0.894, p < 0.0001), and LVM (r = 0.563, p = 0.003). The findings demonstrated that the obese adolescents with NAFLD and subclinical hypothyroidism had a more adverse cardiovascular risk profile and a higher carotid IMT and LVM.

Cardiovascular risk assessment in children with chronic kidney disease

Chronic kidney disease (CKD) is a major factor contributing to cardiovascular (CV) morbidity and mortality with the highest risk in patients on dialysis. An estimation of CV risk is important not only to identify potential modifiable risk factors but also to evaluate the effect of treatments aimed to reduce the risk. Non-invasive methods of measuring vascular changes and circulating biomarkers are available to assess the presence and severity of cardiovascular damage. These include measures of structural (carotid intima-media thickness and coronary artery calcification score) and functional (aortic pulse wave velocity, 24-h ambulatory blood pressure monitoring, ambulatory arterial stiffness index, heart rate variability and flow-mediated dilatation) changes in the vessel wall. In addition, a number of circulating biomarkers of vascular damage and its progression have been studied. Many of these tests are well validated as surrogate markers of future cardiovascular events and death in adult CKD patients, but need technical adaptation, standardization and validation for use in children. With our current state of knowledge, these are best reserved for research studies and scarce clinical resources may be better utilized for preventative strategies to reduce the modifiable risk factors for calcification from early CKD stages.

Selective intrauterine growth restriction in monochorionic twin pregnancies: markers of endothelial damage and metabolomic profile

The aim of this study was to assess the aorta-intima thickness (aIT) and serum metabolomic profile in selective intrauterine growth-restricted (sIUGR) monochorionic diamniotic (MCDA) twin fetuses presenting Doppler velocimetry alterations. Fetal abdominal aIT was measured by ultrasound at 32 weeks of gestation, enrolling 24 MCDA twin fetuses (8 sIUGR and 16 controls). sIUGR twin fetuses were classified into two groups: Group 1 consisted of sIUGR with abnormal umbilical artery (UA) Doppler waveforms and Group 2 included sIUGR with normal UA Doppler. Group 3 were control fetuses appropriate for gestational age (AGA). Fetal blood samples were obtained from the umbilical vein immediately after fetal extraction. A non-targeted metabolomic profiling investigated fetal metabolism alterations by using liquid chromatography-high-resolution mass spectrometry (LC-HRMS). Median fetal aIT was significantly larger in Group 1 (median value = 0.9 mm; range = 0.8-1.0 mm; p < .002) and Group 2 (median value = 0.8 mm; range = 0.7-0.8 mm; p < .002) than in AGA Group 3 (median value = 0.5 mm; range = 0.4-0.6 mm; p < .002). Metabolomic analyses, performed on four sIUGR cases (Group 1) compared with four AGA co-twins, showed an upregulation of phenylalanine, sphingosine, glycerophosphocholine, and choline, and a downregulation of valine, tryptophan, isoleucine, and proline sIUGR Group 1 compared with AGA. Although for metabolomics data only a statistical tendency (and not a statistical significance) was reached due to the small sample size, we believe that our results represent a valid starting point for further in-depth metabolomic and proteomic investigations of sIUGR in MCDA fetuses.

Adiposity, blood pressure, and carotid intima-media thickness in greek adolescents

OBJECTIVE

In children and adolescents with cardiovascular risk factors, the assessment of subclinical target-organ damage is of paramount importance. This study investigated factors associated with carotid intima-media thickness (cIMT) in adolescents.

DESIGN AND METHODS

A cross-sectional study was performed in 448 apparently healthy adolescents recruited from schools (mean age 14 ± 2.2 years, 211 boys), which involved cIMT measurements (common carotid artery) and assessment of lipid profile, glucose, and blood pressure (BP).

RESULTS

The prevalence of overweight/obesity was 28.1%/12.7% and of BP ≥95th percentile 19.6%. Left cIMT was correlated with age (r = 0.10), waist circumference (WC) (0.15), and BP (0.21/0.13, systolic/diastolic) (all P < 0.05). Right cIMT was correlated with waist to hip ratio (WHR) (0.10), whereas the mean of left and right cIMT was correlated with WC (0.12), WHR (0.12), and systolic BP (0.14) (all P < 0.05). After the age of 13 years, boys tended to have higher cIMT than girls, which was significant in the 13-15 years subgroup (P < 0.05). In stepwise multivariate analysis (independent variables: age, gender, WC, WHR, body mass index z-score, lipid parameters, glucose, BP), left cIMT was independently associated with systolic BP; right cIMT with WHR; mean left and right cIMT with WC. Adolescents with BP ≥90th percentile had higher left cIMT than those <90th percentile (0.63 ± 0.09 vs. 0.61 ± 0.09 mm respectively, P < 0.05).

CONCLUSION

Central adiposity and systolic BP appear to be independently associated with increased cIMT values in apparently healthy adolescents. Left side cIMT appears to be superior to right side measurements in terms of association with cardiovascular risk factors.

Carotid Intima Media Thickness as a Reflection of Generalized Atherosclerosis is Related to Body Mass Index in Ischemic Stroke Patients

Background:

Carotid artery intima media thickness reflects the ongoing process of atherosclerosis in the body. The pathologic process occurring in the obese patients in the vascular system is atherosclerosis which is an important cause of ischemic stroke. Body mass index is an indirect measure of obesity in general population.

Aim:

The study was to assess the role of carotid artery intima media thickness as a marker of atherosclerosis and its relation with body mass index in ischemic stroke patients.

Materials and Methods:

Body mass index of the all stroke patients was calculated by using formula body mass in kilograms divided by the square of height in meters. The patients were classified in four groups of body mass index according to Indian standards. Carotid sonography was done to assess the common carotid artery intima media thickness in millimeters by using high resolution 7.5 MHz sonography technique.

Results:

The average Carotid intima media thickness in this study was 9.23mm. There was a significant association found between increasing carotid artery intima media thickness and groups of body mass index (P- <0.05) in ischemic stroke patients.

Conclusions:

Body mass index as an indicator of obesity and carotid intima media thickness both are very important risk factors for ischemic stroke and are associated with each other.

Aortic wall thickness and amniotic fluid albuminuria in growth-restricted twin fetuses

BACKGROUND AND OBJECTIVE

Intrauterine growth restriction (IUGR) may be associated with significantly higher aortic intima-media thickening (aIMT) values. It is unknown if fetal aIMT is associated with glomerulosclerosis and amniotic albuminuria in utero.

DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS

Fetal abdominal aIMT and amniotic albumin/creatinine ratio (ACR) were measured in 126 individual twin fetuses, recruited by the Obstetrics and Gynaecology Clinics of the University of Padua (Italy) Medical Center. The IUGR twin fetuses were classified into two groups: Group A were those fetuses whose estimated fetal weight (EFW) was <10th percentile with pulsatility index >2 SD and Group B were those fetuses whose EFW was <10th percentile and had no velocimetry abnormalities.

RESULTS

The median fetal aIMT was significantly different in the three groups (Group A = 0.9 mm; Group B = 0.7 mm; and appropriate for gestational age (AGA) = 0.5 mm; p < .0001). It was significantly higher in Group A than in the AGA group (p < .0001) and than in the Group B fetuses (p = .003), respectively. In addition, ACR was different in the three groups (Group A = 183,500 mg/g; Group B = 6,4720 mg/g; and AGA = 8,2750 mg/g; p = .0002). It was significantly higher in Group A than in the AGA group (p = .03) and than in Group B (p = .02), respectively.

CONCLUSIONS

Growth-restricted twin fetuses with velocimetry abnormalities present are associated with aIMT and higher ACR levels in amniotic fluid, which could be possible markers in utero of preclinical atherosclerosis, and early glomerulosclerosis.

Fetal aortic wall thickness: a marker of hypertension in IUGR children?

Fetuses with intrauterine growth restriction (IUGR) have significant aortic intima-media thickening (aIMT), which suggests that preclinical atherosclerosis might predispose the infants to hypertension. However, the natural course of aIMT in babies with IUGR remains an open question.The study enrolled 77 pregnant women between January 2007 and August 2009. The fetuses were classified as AGA (appropriate for gestational age) or IUGR, if the estimated fetal weight was between the 10th and 90th percentile or below the 10th percentile (with umbilical artery pulsatility index (PI) >2s.d.), respectively. Anthropometric parameters and aIMT were detected in each IUGR and AGA fetus at a mean gestational age of 32 weeks. The follow-up was performed in 25 IUGR and 25 AGA infants at a mean postnatal age of 18 months; the previous measurements were repeated, and blood pressure measurements were taken. The maximum aIMT was significantly higher in the IUGR fetuses and infants compared with the AGA infants, both in utero (2.05±0.43 vs. 1.05±0.19 mm, P<0.001) and at the follow-up (2.3±0.8 vs. 1.06±0.18 mm, P<0.0001), the resulting values significantly correlated (P=0.018) with one another. The systolic blood pressure was significantly increased in the IUGR subjects (123±16 vs. 104±8.5 mm Hg, P<0.0004), and it correlated with the prenatal and postnatal aIMT values (P<0.0156 and P<0.0054, respectively). The aortic wall thickening progression in IUGR fetuses and infants differed from AGA, which may predispose the infants to hypertension early in life and cardiovascular risk later in life.

Cardiovascular risk assessment in children following kidney transplantation

CV diseases are the leading cause of death among patients with ESRD. RTX decreases the CV risk; however, it still remains definitely higher than that of the general population. Large multicenter and longitudinal studies are difficult to perform and hard end-points of CV events are usually missing among pediatric population. Thus, appropriate estimation of CV risk is of crucial importance to define the potential hazards and to evaluate the effect of treatments aimed to reduce the risk. A number of validated non-invasive methods are available to assess the extent of CV damage in adults, such as calcification scores, cIMT, aPWV, 24-h ABPM, AASI, and HRV; however, they need adaptation, standardization, and validation in pediatric studies. cIMT and PWV are the most promising methods, as pediatric normative values are already present. The up-to-date treatment of ESRD aims not only to save life, but to offer the patient a life expectancy approaching that of the healthy population and to ensure a reasonable quality of life.

Cardiovascular risk in pediatric type 1 diabetes: sex-specific intima-media thickening verified by automatic contour identification and analyzing systems

OBJECTIVES

To improve screening and quantification of subclinical atherosclerosis in children and adolescents with type 1 diabetes (T1D), we investigated the distribution of cardiovascular risk factors (cRFs) and carotid intima-media thickness (cIMT) percentiles with regard to sex-specific differences.

METHODS

This cross-sectional analysis included clinical parameters, blood lipids, and B-mode ultrasound examination of the bilateral mean cIMT using an automatic contour identification procedure combined with computerized analysis.

RESULTS

A total of 270 patients were eligible for evaluation (126 females, mean age 13.7 yr; 144 males, mean age 13.8 yr). In the total group, cIMT was significantly related to sex and diabetes duration but not to age. In males, cIMT was significantly higher than in females and sex-specific cIMT percentiles were calculated. Both pulse pressure and diabetes duration in boys and low-density lipoprotein (LDL)-cholesterol, hemoglobin A1c (HbA1c), and diabetes duration in girls showed a significant association with cIMT.

CONCLUSIONS

On the basis of sex differences of cRFs and cIMT in pediatric T1D, the assessment of sex-specific IMT percentiles facilitates a differentiated interpretation of subclinical atherosclerosis. The underlying diabetes and additional cRFs seem to be more important determinants of intima-media thickening than age. To improve the comparability of IMT measurements of relevant studies, the international harmonization of IMT measurements should be aimed for.

Impact of overweight and obesity in carotid intima-media thickness of portuguese adolescents

AIM

To measure carotid intima-media thickness (cIMT) in obese, overweight and normal-weight Portuguese adolescents, to evaluate the association between body weight early signs of atherosclerosis.

METHODS

Cross-sectional study, enrolling 150 adolescents (50 normal weight, 50 overweight and 50 obese) with mean age of 12.9 years. All underwent clinical, analytical and carotid common artery ultrasonographic evaluation.

RESULTS

After adjusting for systolic blood pressure and plasma High-density lipoprotein, Low-density lipoprotein and Triglycerides levels, higher mean cIMT values were observed in both overweight and obese patients, when compared to normal-weight group. Moreover, adolescents with metabolic syndrome (MS) had greater cIMT [normal-weight: cIMT mean 0.418 mm (95% confidence intervals (95% CI) 0.399-0.437); overweight: 0.461 mm (95% CI: 0.444-0.477); obese: 0.472 mm (95% CI: 0.455-0.488); MS: 0.482 mm (95% CI: 0.444-0.520) p = 0.001]. When normal-weight and overweight adolescents were exclusively compared, differences in cIMT remained significant (p < 0.001). cIMT was positively correlated with body mass index (BMI) (r = 0.439, p < 0.001), waist circumference (r = 0.301, p = 0.018) and diastolic blood pressure (r = 0.266, p = 0.001).

CONCLUSIONS

We have shown that cIMT is positively associated with BMI increase in adolescents, even in moderate overweight ranges, independent of age, gender, systolic blood pressure and plasma lipid concentrations.

Endothelial dysfunction and cardiovascular disease in early-stage chronic kidney disease: cause or association?

Chronic kidney disease (CKD) is strongly associated with cardiovascular disease (CVD); a graded inverse relationship between estimated glomerular filtration rate (eGFR) and cardiovascular event rates has emerged from large-scale observational studies. Chronic kidney disease is also associated with endothelial dysfunction (ED) although the precise relationship with GFR and the "threshold" at which ED begins are contentious. Abnormal endothelial function is certainly present in late-stage CKD but data in early-stage CKD appear confounded by disease states such as diabetes and hypertension which themselves promote ED. Thus, the direct effect of a reduction in GFR on endothelial function and, therefore, cardiovascular (CV) risk is far from completely established. In human studies, the precise duration of kidney impairment is seldom known and the onset of CVD often insidious, making it difficult to determine exactly when CVD first appears in the context of CKD. Kidney donors provide a near-ideal experimental model of CKD; subjects undergo an acute change from normal to modestly impaired renal function at the time of nephrectomy and lack the confounding co-morbidity that has made observational studies of CKD patients so challenging to interpret. By examining changes in endothelial function in living kidney donors before and after nephrectomy, useful insight might be gained into the pathophysiology of CVD in CKD and help determine whether targeting ED or the renal disease itself has the potential to reduce CV risk.

Feasibility of very-high resolution ultrasound to assess elastic and muscular arterial wall morphology in adolescents attending an outpatient clinic for obesity and lipid abnormalities

OBJECTIVE

Atherosclerosis begins during early life and is accelerated in individuals with cardiovascular risk factors. We hypothesized that very-high resolution ultrasound (VHRU, 25-55 MHz) could feasibly detect early arterial changes in adolescents with risk factors.

METHODS

We prospectively imaged the carotid, brachial and radial arterial morphology (far wall intima-media thickness, IMT; adventitia thickness, AT) by VHRU in 58 youths (age 14 ± 2 years) attending a Pediatric Preventive Cardiology Clinic for assessment and management of cardiovascular risk factors and compared the findings to those from an age-matched group of 67 controls.

RESULTS

Brachial and radial imaging was successful for all subjects. The carotid far wall could not be imaged in 7% of the patients due to limitations in penetration. VHRU image quality was related to body size and imaging depth. Imaging and analysis time were 12 ± 3 and 18 ± 3 min, respectively. Carotid IMT was increased in patients (0.42 ± 0.05 vs. 0.40 ± 0.06 mm, p = 0.05). No differences were found in brachial or radial IMT or AT vs. controls. Age, male gender, body mass index, systolic blood pressure (BP), but not lipid levels, were associated with arterial IMT in regression analyses.

CONCLUSION

VHRU is feasible in imaging carotid and peripheral muscular artery IMT in adolescents. The arterial IMT is associated with age, gender, adiposity and systolic BP, but not lipid levels, in this adolescent population. Further studies including patients with manifest clinical atherosclerosis are needed to assess if VHRU has applications in atherosclerosis research.

Increased intima-media thickness of the carotid artery in childhood: a systematic review of observational studies

Increased carotid intima-media thickness (cIMT) in adults may be caused by a childhood exposure to cardiovascular risk factors. We systematically reviewed observational studies to determine whether obesity, insulin-dependent diabetes mellitus (IDDM), dyslipidemia (DL), hypertension (HT), and chronic renal failure (CRF) are associated with increased cIMT in children and adolescent patients compared with control subjects. We performed a PubMed literature search from January 1986 to February 2010. Two reviewers separately verified the inclusion criteria of relevant studies for the objective of the review. The data extracted in the patient and control groups were sample size, age, gender, cIMT measurement methods, cIMT values, and statistical analysis results. From 348 citations, 65 cross-sectional studies (2 cited twice) with case-control design met the inclusion criteria: 26 in obesity, 14 in IDDM, 11 in DL, 8 in HT, and 8 in CRF. cIMT measurement protocols varied according to the studies, with measurements being performed on the common carotid artery in 65/67 cases and on the far wall in 57/67 cases. From the 67 studies cited, 22/26 reported a significantly increased cIMT in obese children and adolescents compared with the control group, 8/14 in IDDM patients, 10/11 in DL patients, 7/8 in HT patients, and 8/8 in CRF patients.

CONCLUSION

Despite the heterogeneity of ultrasound measurement methods, cIMT was significantly increased in 55 out of the 67 cited studies, confirming early vascular damages in pediatric populations with an increased future risk for vascular diseases.

Intrauterine growth restriction is associated with persistent aortic wall thickening and glomerular proteinuria during infancy

Low birth weight, caused either by preterm birth or by intrauterine growth restriction, has recently been associated with increased rates of adult renal and cardiovascular disease. Since aortic intima–media thickening is a noninvasive marker of preclinical vascular disease, we compared abdominal aortic intima–media thickness among intrauterine growth restricted and equivalent gestational age fetuses in utero and at 18 months of age. The relationship between intrauterine growth restriction, fetal aortic thickening, and glomerular function during infancy was measured by enrolling 44 mothers with single-fetus pregnancies at 32 weeks gestation: 23 growth restricted and 21 of appropriate gestational age as controls. Abdominal aortic intima–media thickness was measured by ultrasound at enrollment and again at 18 months of age. Fetuses with intrauterine growth restriction had significantly higher abdominal aortic intima–media thickness compared with age controls when measured both in utero and at 18 months. At 18 months, the median urinary microalbumin and median albumin–creatinine ratio were significantly higher in those infants who experienced intrauterine growth restriction compared to the controls. Our results show that intrauterine growth restriction is associated with persistent aortic wall thickening and significantly higher microalbuminuria during infancy.

Consequences in infants that were intrauterine growth restricted

Intrauterine growth restriction is a condition fetus does not reach its growth potential and associated with perinatal mobility and mortality. Intrauterine growth restriction is caused by placental insufficiency, which determines cardiovascular abnormalities in the fetus. This condition, moreover, should prompt intensive antenatal surveillance of the fetus as well as follow-up of infants that had intrauterine growth restriction as short and long-term sequele should be considered.

Long-term follow-up of cardiovascular risk factors after exercise training in obese children

OBJECTIVE

We previously demonstrated beneficial effects of physical activity on cardiovascular disease (CVD) risk factors, body mass index (BMI) and fat mass in pre-pubescent obese children. The aim of this study was to determine whether these changes were maintained 2 years later.

METHODS

Two years after the Randomised Controlled Trial, we performed a follow-up study with 20 of 38 subjects (11.4 ± 1.8 years). Outcomes included blood pressure (BP) by ambulatory monitoring; arterial function and structure using high-resolution ultrasound, BMI, body composition by dual-energy x-ray absorptiometry (DXA), physical activity using accelerometer, and biological markers.

RESULTS

During the 2-year follow-up period, mean 24-hour diastolic BP z-score significantly decreased (1.4 ± 1.2 vs. 0.3 ± 1.4, p = 0.04), while systolic BP z-score was slightly reduced (2.4 ± 1.5 vs. 1.4 ± 1.7, p = 0.067). Blood pressure changes were greater in children who diminished their BMI z-score compared with the ones who did not. Systolic hypertension rates dropped from 50 to 28% and diastolic hypertension from 42 to 6%. In addition, arterial intima-media thickness (0.51 ± 0.03 vs. 0.51 ± 0.06, p = 0.79), BMI z-score (2.9 ± 0.8 vs. 2.9 ± 1.1 kg.cm(-2), p = 0.27), body fat (41.9 ± 6.9 vs. 42.8 ± 6.7%; p = 0.39) and physical activity count (703 ± 209 vs. 574 ± 244 cpm, p = 0.30) were stable.

CONCLUSION

To our knowledge, this is the first study reporting that beneficial effects on adiposity and CVD risk factors of a physical activity centred intervention are sustained 2 years after the cessation of training in obese children. Subjects stabilized BMI z-score and maintained physical activity with further improvement of BP and stabilization of arterial wall remodelling. We conclude that it is important to encourage physical activity in this population. Effects of Aerobic Exercise Training on Arterial Function and Insulin Resistance Syndrome in Obese Children: A Randomised Controlled Trial: NCT00801645.

Pediatric hypertension update

PURPOSE OF REVIEW

The field of childhood hypertension has been changing rapidly since publication of the most recent consensus guidelines contained in the 2004 'Fourth Report'.

RECENT FINDINGS

Several epidemiologic studies have indicated that the prevalence of hypertension in children and adolescents is on the increase. A major factor behind this increase is the childhood obesity epidemic. There is substantial new information on the frequency of hypertensive target-organ damage in the young, including vascular, cardiac and renal effects. These data have led some authorities to recommend changes in how hypertension is evaluated and managed in the young.

SUMMARY

There has been significant new knowledge gained about many aspects of childhood hypertension over the past 5 years. Clinicians who care for children and adolescents with high blood pressure should familiarize themselves with these new data and incorporate them into their clinical decision-making.

When does the cardiovascular disease appear in patients with chronic kidney disease?

Cardiovascular disease is a leading cause of long-term morbidity and mortality among children with chronic kidney disease (CKD). At which stage of CKD these appear in children is unknown. This study aimed to determine the prevalence of cardiovascular disease in pediatric CKD patients and to explore the relationship of these changes and treatment methods. The study enrolled pediatric patients with stages 1-5 CKD including 20 patients receiving predialysis (PreD), 8 receiving peritoneal dialysis, and 14 receiving hemodialysis. Aortic stiffness, defined as decreased aortic strain (S) and increased pressure strain normalized by diastolic pressure (Ep*), was described. Sonography of the common carotid artery and left ventricle was performed. The mean age of the children was 13.3 + or - 5.3 years. The patients had lower S values (0.35 + or - 0.23) than the control subjects (0.44 + or - 0.2) (P < 0.05) but higher Ep* (2.46 + or - 1.31 vs. 1.32 + or - 0.09; P < 0.05). Aortic stiffness was found in 13 patients. The PreD group had lower As levels than the dialysis group but higher levels than the control group. The patients (n = 32) had greater carotid intima-media thickness than the control subjects (0.58 + or - 0.14 vs. 0.35 + or - 0.12; P < 0.05). The intima-media thickness was greatest in the PreD group (P < 0.05). The patients had a higher left ventricular mass index (LVMI; 42.4 + or - 15.6) than the control subjects (28.8 + or - 8.47) (P < 0.05) and a larger left ventricle end diastolic diameter (LVEDD; 3.44 + or - 0.76 vs. 2.59 + or - 0.34; P < 0.05). Left ventricular hypertrophy was found in 32 patients. Both LVMI and LVEDD were higher in the groups receiving hemodialysis and lower in the PreD group. Increased carotid-intima media thickness and left ventricle hypertrophy appeared without hypertension in the PreD group. The indications and timing of dialysis should be reevaluated for children with CKD. In the dialysis groups, fewer cardiovascular changes were found with peritoneal dialysis than with hemodialysis. Therefore, peritoneal dialysis should be preferable to hemodialysis for children with CKD.

Hypertension in adolescents

In adults, hypertension has long been perceived as a public health problem. By contrast, its impact in childhood is far less appreciated. In fact, quite often, high blood pressure in children is not even diagnosed. Blood pressure is a vital sign that is routinely obtained during a physical examination of adults, but only very seldom in children. The diagnosis of hypertension in children is complicated because 'normal' blood pressure values vary with age, sex and height. As a consequence, almost 75% of the cases of arterial hypertension and 90% of the cases of prehypertension in children and adolescents are currently undiagnosed. Furthermore, adolescence hypertension is increasing in prevalence as the prevalence of pediatric obesity has increased. Ambulatory blood pressure monitoring is a useful method for risk evaluation in adolescents. In addition to being viewed as an important cardiovascular risk factor in adolescents, elevated blood pressure should prompt a thorough search for other modifiable risk factors that, if treated, might reduce teenagers' risk of developing cardiovascular disease in adulthood. Thus, assessing blood pressure values in children represents one of the most important measurable markers of cardiovascular risk later in life and a major step in preventive medicine.

Chronic life stress, cardiovascular reactivity, and subclinical cardiovascular disease in adolescents

OBJECTIVE

To examine cross-sectional and longitudinal relationships between chronic life stress, cardiovascular reactivity, and a marker of subclinical cardiovascular disease in a multiethnic sample of adolescents.

METHODS

Participants were 158 healthy adolescents who completed self-report measures of chronic negative life stress as well as assessments of heart rate and blood pressure reactivity to acute laboratory stressors at two time points, approximately 3.3 years apart. At Time 2, intima-media thickness (IMT), a measure of subclinical atherosclerosis, was also measured.

RESULTS

In hierarchical regression models adjusting for demographic variables and body mass index, chronic negative life stress at Time 2 was concurrently associated with greater diastolic blood pressure (DBP) reactivity to stress (beta = 0.18, p = .016), but neither chronic stress nor cardiovascular reactivity was associated concurrently with IMT. Increasing life stress from Time 1 to Time 2 was accompanied by increasing cardiovascular reactivity (beta = 0.14-0.20, p < .05), and increasing DBP reactivity over time was also associated with IMT (beta = 0.24, p = .03), although increasing chronic life stress was not directly related to IMT.

CONCLUSIONS

Adolescents exposed to chronic, negative stressors that worsen over time may show heightened cardiovascular reactivity that puts them at risk for subclinical atherosclerosis.

Intima-media thickness and liver histology in obese children and adolescents with non-alcoholic fatty liver disease

OBJECTIVE

To evaluate the relationship between biopsy-proven non-alcoholic fatty liver disease (NAFLD) and carotid artery intima-media thickness (CIMT) in children and adolescents.

METHODS

A case-control study was performed. Cases were 31 mostly obese children and adolescents, with NAFLD detected at ultrasonography, and confirmed by liver biopsy. Controls were 49 mostly obese children matched for gender, age and BMI without NAFLD at ultrasonography and with normal levels of aminotransferases. Besides standard laboratory measurements, subjects underwent an oral glucose tolerance test to evaluate glucose tolerance and to estimate whole body insulin sensitivity (ISI).

RESULTS

CIMT was similar in cases and controls on the right side but higher in cases on the left side. Although statistically significant, this difference is unlikely to be clinically relevant because of substantial overlap of CIMT values between cases and controls. Moreover, there was no association between CIMT and the severity of steatosis, ballooning, fibrosis, and the non-alcoholic steato-hepatitis score in cases. At multivariable analysis in the pooled sample (n=80), age and the z-score of BMI but not NAFLD, gender, blood pressure and triglycerides, were associated with CIMT.

CONCLUSIONS

We found no association between CIMT and NAFLD in children and adolescents. More importantly, there was no association between histological severity and CIMT in children with NAFLD.

Cardiovascular disease in CKD in children: update on risk factors, risk assessment, and management

In young adults with onset of chronic kidney disease in childhood, cardiovascular disease is the most common cause of death. The likely reason for increased cardiovascular disease in these patients is a high prevalence of traditional and uremia-related cardiovascular disease risk factors during childhood chronic kidney disease. Early markers of cardiomyopathy, such as left ventricular hypertrophy and left ventricular dysfunction, and early markers of atherosclerosis, such as increased carotid artery intima-media thickness, carotid arterial wall stiffness, and coronary artery calcification, frequently are found in this patient population. The purpose of this review is to provide an update of recent advances in the understanding and management of cardiovascular disease risks in this population.