Carotid Intima-media Thickness In Adolescents Research Articles

Phthalate exposure increases subclinical atherosclerosis in young population

The link between phthalate exposure and the risk of subclinical atherosclerosis in young population remains unclear. This study investigated the association between phthalate exposure and subclinical atherosclerosis, in terms of carotid intima-media thickness (CIMT), in young population. From a nationwide mass urine screening for renal health, conducted in 1992–2000 among school children 6–18 years of age in Taiwan, we recruited 789 subjects to participate in the cardiovascular health examination in 2006–2008. Among them, 787 received measurements of 7 urinary phthalate metabolites and CIMT. Results showed both mean and maximal values of CIMT at all segments of carotid arteries significantly increased with the urinary mono-2-ethylhexyl phthalate (MEHP), ∑ di-(2-ethylhexyl) phthalate (DEHP), and mono-n-butyl phthalate (MnBP) in a dose-response relationship after adjustment for multiple linear regression models. Multivariate logistic regression analysis showed that higher quartiles of urinary concentrations of MEHP, ∑DEHP, and MnBP were associated with a higher risk of thicker CIMT. Compared to subjects with the lowest quartile (Q1) of urinary MEHP, the adjusted odds ratios (95% confidence interval) for thicker CIMT among subjects with higher urinary MEHP were 2.13 (1.18–3.84) at Q2, 4.02 (2.26–7.15) at Q3 and 7.39 (4.16–13.12) at the highest Q4. In conclusion, urinary phthalate metabolites of MEHP, ∑DEHP, and MnBP are strongly associated with CIMT in adolescents and young adults in Taiwan.

Association of serum levels of 4-tertiary-octylphenol with cardiovascular risk factors and carotid intima-media thickness in adolescents and young adults

In the family of alkylphenolic compounds, 4-tertiary-Octylphenol (4-t-OP) is extensively used in many products. In animal and in vitro studies, 4-t-OP exposure has been linked to cardiovascular disease (CVD) risk factors; however, there are no previous human epidemiological studies. In this study, 886 subjects were recruited from a cohort of Taiwanese adolescents and young adults to study the relationship between serum levels of 4-t-OP, CVD risk factors, and common carotid artery intima-media thickness (CIMT). The geometric mean (SD) 4-t-OP concentration was 32.52 (1.71) ng/mL. We found that serum levels of 4-t-OP were negatively associated with markers of glucose homeostasis (insulin, homeostasis model assessment of insulin resistance (HOMA-IR) and homeostasis model assessment of β-cell function (HOMA-β)), z score of body mass index (BMI z score) and CIMT but were positively associated with lipid profiles (high density lipoprotein cholesterol (HDL-C), Apolipoprotein A1). A one-unit elevation in natural log-transformed 4-t-OP (ng/mL) was negatively correlated with CIMT (mm) (β = −0.029, SE = 0.003, P < 0.001) in multiple linear regression analyses. The relationship between 4-t-OP and CIMT remained the same in all subgroups or if bisphenol A (BPA) was considered a covariate. In this study, we observed that higher levels of 4-t-OP levels were negatively correlated with markers of glucose homeostasis, BMI z score, and CIMT; positively correlated with lipid profiles (HDL-C and apolipoprotein A) in this cohort. Future research on exposure to 4-t-OP and CVD risk factors is warranted.

Short Sleep Duration Is Weakly Associated with Carotid Intima-Media Thickness in Adolescents

To investigate the relationship between sleep duration and carotid intima-media thickness (CIMT) in adolescents. We hypothesized that short sleep duration was associated with an increased CIMT. This was a cross-sectional study. Healthy participants aged 10-18 years were recruited from a school-based cohort established to examine the prevalence of obstructive sleep apnea in Hong Kong. All participants completed a prospective 7-day sleep diary, underwent anthropometric measurements, overnight polysomnography, and CIMT assessment. Overweight participants or those with an obstructive apnea hypopnea index of ≥5 were excluded from analysis. Regression analysis was used to assess the association between CIMT and sleep duration and other possible correlates. One hundred forty-two participants completed the assessments. Male participants tended to have shorter sleep duration than females (P = .012). There were no differences in age, body mass index, Tanner developmental stage, or parental history of hypertension between groups of different sleep durations. There was a weak but significant association between short sleep duration and CIMT (r = -0.273; P < .001). Sleep duration was found to have a weakly negative association with CIMT. Further research is needed to determine whether adult adverse cardiovascular events may originate in childhood owing to short sleep duration.

Phthalate Exposure is associated with Carotid Intima-Media Thickness in Adolescents and Young Adults

Background/Aim: Exposure to phthalates has been linked to cardiovascular risk factors. However, it is unclear regarding phthalates exposure and the risk of subclinical atherosclerosis. This study investigated the association between phthalates exposure and carotid intima-media thickness (CIMT) in young population. Methods: From a nationwide mass urine screening for renal health, conducted in 1992-2000 among school children 6 to 18 years of age in Taiwan, we recruited 789 subjects to participate the cardiovascular health examination in 2006-2008. Among them, 787 received measurements of 7 urinary phthalate metabolites and CIMT. Results: Both mean and maximal values of CIMT at all segments of carotid arteries significantly increased with the urinary mono-2-ethylhexyl phthalate (MEHP), ∑MEHP, and mono-n-butyl phthalate (MnBP) in a dose-response relationship after adjustment for multiple linear regression models. Multivariate logistic regression analysis showed that higher quartiles of urinary concentrations of MEHP, ∑MEHP, and MnBP were associated with a higher risk of thicker CIMT. Compared to subjects with the lowest quartile (Q1) of urinary MEHP, the adjusted odds ratios (aORs) (95% confidence interval (CI)) for thicker CIMT among subjects with higher urinary MEHP were 2.13(1.18-3.84) at Q2, 4.02(2.26-7.15) at Q3 and 7.39(4.16-13.12) at the highest Q4. Comparing those with lowest urinary MnBP, the corresponding aORs (95% CI) were 1.84 (1.08-3.15) for subjects at Q3, and 2.80 (1.65-4.75) for subjects at the highest Q4. Conclusions: Urinary phthalate metabolites of MEHP, ∑MEHP, and MnBP are strongly associated with CIMT in adolescents and young adults in Taiwan.

Adiposity has no direct effect on carotid intima-media thickness in adolescents and young adults: Use of structural equation modeling to elucidate indirect & direct pathways

BackgroundCarotid intima-media thickness (cIMT) is associated with CV events in adults. Thicker cIMT is found in youth with CV risk factors including obesity. Which risk factors have the most effect upon cIMT in youth and whether obesity has direct or indirect effects is not known. We used structural equation modeling to elucidate direct and indirect pathways through which obesity and other risk factors were associated with cIMT. MethodsWe collected demographics, anthropometrics and laboratory data on 784 subjects age 10–24 years (mean 18.0 ± 3.3 years). Common, bulb and internal carotid cIMT were measured by ultrasound. Multivariable regression analysis was performed to assess independent determinants of cIMT. Analyses were repeated with structural equation modeling to determine direct and indirect effects. ResultsMultivariable regression models explained 11%–22% of variation of cIMT. Age, sex and systolic blood pressure (BP) z-score were significant determinants of all cIMT segments. Body mass index (BMI) z-score, race, presence of type 2 diabetes mellitus (T2DM), hemoglobin A1c (HbA1c) and non-HDL were significant for some segments (all p = 0.05). The largest direct effect on cIMT was age (0.312) followed by BP (0.228), Blood glucose control (0.108) and non-HDL (0.134). BMI only had a significant indirect effect through blood glucose control, BP & non-HDL. High sensitivity C-reactive protein (CRP) had a small indirect effect through blood glucose control (all p = 0.05). ConclusionsAge and BP are the major factors with direct effect on cIMT. Glucose and non-HDL were also important in this cohort with a high prevalence of T2DM. BMI only has indirect effects, through other risk factors. Traditional CV risk factors have important direct effects on cIMT in the young, but adiposity exerts its influence only through other CV risk factors.

Abstract 13223: Structural Equation Modeling Demonstrates only an Indirect Effect of Obesity on Carotid Intima-Media thickness in Adolescents and Young Adults

Introduction: Increased carotid intima-media thickness (cIMT) is associated with cardiovascular (CV) events in adults. Thicker cIMT is found in youth with elevated CV risk factors including obesity although biologically plausible reasons for a direct effect are not clear. We hypothesized that obesity affects cIMT only indirectly through other CV risk factors and this could be demonstrated with use of structural equation modeling (SEM). Methods: Ultrasound of the right and left common, bulb and internal carotid arteries was performed in 784 adolescent and young adults (10-24 years old, 65% female, 41% Caucasian, 32% T2DM). Demographics, anthropometrics and fasting laboratory data were collected. Traditional multiple regression analyses (MRA) were performed to assess independent determinants of cIMT. Analyses were then repeated with SEM. Results: MRA models explained 11%-22% of variation of common, bulb and internal cIMT. Obesity, age, sex and SBP z-score were significant determinants of all cIMT segments. Race, presence of T2DM, HbA1c and non-HDL contributed for some segments. In SEM, latent variable “cIMT” was used to represent the 3 segments of cIMT. Latent variable “BP” was extracted from SBP and DBP z-score. Latent variable “BGC” (blood glucose control) was extracted from fasting glucose and HbA1c. The final SEM explained a larger amount of the variance of cIMT (43%). The largest direct effect on cIMT was age followed by BP, blood glucose control and non-HDL. BMI, another central risk factor in the pathway towards atherosclerosis, only had a significant indirect effect through blood glucose control, BP &amp; non-HDL. CRP had a small indirect effect through blood glucose control. We conclude that traditional CV risk factors have important direct effects on cIMT in adolescents and young adults but adiposity exerts its influence only through other CV risk factors. SEM may be a useful tool in modeling complex biological pathways.

Association of socioeconomic status, truncal fat and sICAM-1 with carotid intima-media thickness in adolescents: The HELENA study

ObjectiveTo measure the carotid intima-media-thickness (cIMT) and to assess its determinant factors in healthy adolescents. Methods319 adolescents aged 12.5–17.5 years (135 boys, 184 girls) were enrolled in this cross-sectional study. cIMT and carotid diameter were measured by high-resolution B-mode ultrasound. Anthropometric parameters, blood pressure, physical activity (PA), aerobic fitness and dietary intakes were assessed. Socioeconomic status was determined with the family affluence scale (FAS 4). Serum biological markers (lipids, glucose, high-sensitivity C-reactive protein, soluble adhesion molecules) were measured in a subsample of 96 adolescents. ResultsMultiple regression analysis showed that cIMT was positively associated with truncal fat (p = 0.021) and negatively with FAS 4 (p = 0.002) independently of age and blood pressure. There were no significant associations between cIMT and PA, fitness and dietary intakes. In the subsample soluble intercellular adhesion molecule 1 was positively correlated with cIMT (p = 0.017), independently of truncal fat, age and blood pressure. ConclusionsLow socioeconomic conditions and increased truncal fat are associated with greater carotid intima-media-thickness in adolescents.

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.

Risk Factors Associated With Aortic and Carotid Intima-Media Thickness in Adolescents and Young Adults: The Muscatine Offspring Study

This study sought to determine whether cardiovascular risk factors are associated with aortic intima-media thickness (aIMT) and carotid intima-media thickness (cIMT) in adolescents and young adults. Atherosclerotic lesions begin developing in youth, first in the distal abdominal aorta and later in the carotid arteries. Knowledge of how risk factors relate to aIMT and cIMT may help in the design of early interventions to prevent cardiovascular disease. Participants were 635 members of the Muscatine Offspring cohort. The mean aIMT and cIMT were measured using an automated reading program. The mean (SD) values of aIMT and cIMT were 0.63 (0.14) and 0.49 (0.04) mm, respectively. In adolescents (age 11 to 17 years), aIMT was associated with triglycerides, systolic blood pressure (SBP), diastolic blood pressure (DBP), body mass index (BMI), and waist/hip ratio, after adjusting for age, sex, and height. In young adults (age 18 to 34 years), aIMT was associated with those same 5 risk factors, plus high-density lipoprotein cholesterol and pulse pressure. In adolescents, cIMT was associated with SBP, pulse pressure, heart rate, BMI, and waist/hip ratio. In young adults, cIMT was associated with total cholesterol, low-density lipoprotein cholesterol, triglycerides, SBP, DBP, BMI, waist/hip ratio, and glycosylated hemoglobin. In both age groups, aIMT and cIMT were significantly correlated with the Pathobiological Determinants of Atherosclerosis in Youth coronary artery risk score. Both aIMT and cIMT are associated with cardiovascular risk factors. Using aIMT in adolescents gives information beyond that obtained from cIMT alone. Measurement of aIMT and cIMT may help identify those at risk for premature cardiovascular disease.

Statin Treatment in Children With Familial Hypercholesterolemia

We previously demonstrated in a randomized placebo-controlled trial that 2-year pravastatin treatment induced a significant regression of carotid intima-media thickness (IMT) in 8- to 18-year-old children with familial hypercholesterolemia. Subsequently, we continued to follow up these children to explore the relation between the age of statin initiation and carotid IMT after follow-up on statin treatment. We also examined safety aspects of statin therapy during this long-term follow-up. All 214 children who initially participated in the previous placebo-controlled study were eligible for the follow-up study. After completion of the placebo-controlled study, all children continued treatment with pravastatin 20 or 40 mg, depending on their age. Blood samples were taken on a regular basis for lipids and safety parameters, and a carotid IMT measurement was performed after an average treatment period of 4.5 years. Follow-up data for 186 children were available for the statistical analyses. Multivariate analyses revealed that age at statin initiation was an independent predictor for carotid IMT after follow-up with adjustment for carotid IMT at initiation of statin treatment, sex, and duration of treatment. Early initiation of statin treatment was associated with a subsequently smaller IMT. Furthermore, no serious laboratory adverse events were reported during follow-up, and statin treatment had no untoward effects on sexual maturation. These data indicate that early initiation of statin treatment delays the progression of carotid IMT in adolescents and young adults. The present study shows for the first time that early initiation of statin therapy in children with familial hypercholesterolemia might be beneficial in the prevention of atherosclerosis in adolescence.