Histopathological modifications of early atherosclerotic lesions by risk factors--findings in PDAY subjects

Long-Term Cardiovascular Outcomes in Children and Adolescents With Hypertension

Importance

Hypertension affects 6% of all children, and its prevalence is increasing. Childhood hypertension tracks into adulthood and is associated with subclinical cardiovascular disease; however, there is a lack of evidence linking childhood hypertension to cardiovascular outcomes, which may contribute to underdiagnosis and undertreatment.

Objective

To determine the long-term associated risk of major adverse cardiac events (MACE) among children diagnosed with hypertension.

Design, Setting, and Participants

This was a population-based, retrospective, matched cohort study conducted from 1996 to 2022. The study included all children (aged 3-18 years) alive in Ontario, Canada, from 1996 to 2021, who were identified using provincial administrative health databases. Children with prior kidney replacement therapy were excluded.

Exposure

Incident hypertension diagnosis, identified by validated case definitions using diagnostic and physician billing claims. Each case was matched with 5 controls without hypertension by age, sex, birth weight, maternal gestational hypertension, prior comorbidities (chronic kidney disease, diabetes, cardiovascular surgery), and a propensity score for hypertension.

Main Outcomes and Measures

The primary outcome was MACE (a composite of cardiovascular death, stroke, hospitalization for myocardial infarction or unstable angina, or coronary intervention). Time to MACE was evaluated using the Kaplan-Meier method and Cox proportional hazards regression.

Results

A total of 25 605 children (median [IQR] age, 15 [11-17] years; 14 743 male [57.6%]) with hypertension were matched to 128 025 controls without hypertension. Baseline covariates were balanced after propensity score matching, and prior comorbidities were uncommon (hypertension vs control cohort: malignancy, 1451 [5.7%] vs 7908 [6.2%]; congenital heart disease, 1089 [4.3%] vs 5408 [4.2%]; diabetes, 482 [1.9%] vs 2410 [1.9%]). During a median (IQR) of 13.6 (7.8-19.5) years of follow-up, incidence of MACE was 4.6 per 1000 person-years in children with hypertension vs 2.2 per 1000 person-years in controls (hazard ratio, 2.1; 95% CI, 1.9-2.2). Children with hypertension were at higher associated risk of stroke, hospitalization for myocardial infarction or unstable angina, coronary intervention, and congestive heart failure, but not cardiovascular death, compared with nonhypertensive controls.

Conclusions and Relevance

Children diagnosed with hypertension had a higher associated long-term risk of MACE compared with controls without hypertension. Improved detection, follow-up, and control of pediatric hypertension may reduce the risk of adult cardiovascular disease.

Validity of Atherosclerotic Calcified Lesions Observed on Low-Dose Computed Tomography and Cardio-Ankle Vascular Index as Surrogate Markers of Atherosclerosis Progression

The significance of atherosclerotic calcified lesions observed on low-dose computed tomography (LDCT) performed during general checkups was investigated. The coronary arteries (CA), ascending aorta and aortic arch (AAAA), descending thoracic aorta (DTA), and abdominal aorta (AA) were examined. Semiquantitative calcified index analysis of the DTA and AA in terms of atherosclerosis risk factors and cardio-ankle vascular index (CAVI) measurements was also performed. We included 1594 participants (mean age: 59.2 years; range: 31-91 years). The prevalence of calcified lesions was 71.0%, 66.6%, 57.2%, and 37.9% in the AA, CA, AAAA, and DTA, respectively. Age-related advances in calcification among participants with no major risk factors, revealed that calcification appeared earliest in the AA, followed by the CA, AAAA, and DTA. Participants with calcified lesions in all arteries had a significantly greater CAVI than those without calcification. The CAVI was negatively correlated with low-density lipoprotein cholesterol levels, particularly in participants without calcified lesions in the DTA. Calcified lesions on LDCT could indicate the end stage of atherosclerotic lesions. The CAVI can be used to assess atherosclerotic changes at all stages of disease progression. A combination of LDCT and CAVI could be used as a routine non-invasive assessment of atherosclerosis.

Signature transcriptome analysis of stage specific atherosclerotic plaques of patients

Background

Inflammation plays an important role in all the stages of atherosclerotic plaque development. The current study aimed at assessing the altered expression of genes functioning in inflammation within the early stage (ES) and advanced stage (AS) atherosclerotic plaques obtained from patients undergoing coronary artery bypass grafting (CABG) surgery and identifying biomarker panel/s that may detect the status of plaque stages using peripheral blood samples.

Methods

A section of ES and AS plaques and normal left internal mammary arteries (LIMA) were obtained from 8 patients undergoing the CABG surgery. Total RNA isolated was analyzed for mRNA and miRNA expression profile by Affymetrix arrays. A significant number of mRNAs was found to be differentially expressed in ES and AS plaque tissues relative to LIMA. The pathway analysis of differentially expressed mRNAs in the two plaque stages was also performed using DAVID Bioinformatics Database.

Results

The mRNAs were found to be involved in critical inflammatory processes such as the toll-like receptor signaling pathway and cytokine-cytokine receptor interaction. Few miRNAs targeting these mRNAs were also altered in the two plaque conditions. QRT-PCR results showed a similar expression pattern of a few of the mRNAs and miRNAs in peripheral blood of the same patients relative to healthy controls.

Conclusion

Changes in mRNA and miRNA expression associated with various inflammatory processes occur in different atherosclerotic stage plaques as well as peripheral blood. Detection of such variations in patients’ blood can be used as a possible prognostic tool to detect and/or predict the risk and stage of atherosclerosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12920-022-01250-8.

High blood pressure in children and adolescents: current perspectives and strategies to improve future kidney and cardiovascular health

Hypertension is one of the most common causes of preventable death worldwide. The prevalence of pediatric hypertension has increased significantly in recent decades. The cause of this is likely multifactorial, related to increasing childhood obesity, high dietary sodium intake, sedentary lifestyles, perinatal factors, familial aggregation, socioeconomic factors, and ethnic blood pressure (BP) differences. Pediatric hypertension represents a major public health threat. Uncontrolled pediatric hypertension is associated with subclinical cardiovascular disease and adult-onset hypertension. In children with chronic kidney disease (CKD), hypertension is also a strong risk factor for progression to kidney failure. Despite these risks, current rates of pediatric BP screening, hypertension detection, treatment, and control remain suboptimal. Contributing to these shortcomings are the challenges of accurately measuring pediatric BP, limited access to validated pediatric equipment and hypertension specialists, complex interpretation of pediatric BP measurements, problematic normative BP data, and conflicting society guidelines for pediatric hypertension. To date, limited pediatric hypertension research has been conducted to help address these challenges. However, there are several promising signs in the field of pediatric hypertension. There is greater attention being drawn on the cardiovascular risks of pediatric hypertension, more emphasis on the need for childhood BP screening and management, new public health initiatives being implemented, and increasing research interest and funding. This article summarizes what is currently known about pediatric hypertension, the existing knowledge-practice gaps, and ongoing research aimed at improving future kidney and cardiovascular health.

Cardiometabolic risk factors in siblings from a statewide screening program

BACKGROUND

The Coronary Artery Risk Detection in Appalachian Communities (CARDIAC) Project is a state-wide risk factor screening program that operated in West Virginia for 19 years and screened more than 100,000 5th graders for obesity, hypertension, and dyslipidemia.

OBJECTIVES

We investigated siblings in the CARDIAC Project to assess whether cardiometabolic risk factors (CMRFs) correlate in siblings.

METHODS

We identified 12,053 children from 5752 families with lipid panel, blood pressure, and anthropometric data. A linkage application (LinkPlus from the U.S. Centers for Disease Control and Prevention) matched siblings based on parent names, addresses, telephone numbers, and school to generate a linkage probability curve. Graphical and statistical analyses demonstrate the relationships between CMRFs in siblings.

RESULTS

Siblings showed moderate intraclass correlation coefficient of 0.375 for low-density lipoprotein cholesterol (LDL-C), 0.34 for high-density lipoprotein cholesterol (HDL-C), and 0.22 for triglyceride levels. The body mass index (BMI) intraclass correlation coefficient (0.383) is slightly better (2%) than LDL-C or HDL-C, but the standardized beta values from linear regression suggest a 3-fold impact of sibling LDL-C over the child's own BMI. The odds ratio of a second sibling having LDL-C < 110 mg/dL with a first sibling at that level is 3.444:1 (Confidence Limit 3.031-3.915, P < .05). The odds ratio of a sibling showing an LDL-C ≥ 160 mg/dL, given a first sibling with that degree of elevated LDL-C is 29.6:1 (95% Confidence Limit: 15.54-56.36). The individual LDL-C level correlated more strongly with sibling LDL-C than with the individual's own BMI. Seventy-eight children with LDL-C > 160 mg/dL and negative family history would have been missed, which represents more than half of those with LDL-C > 160 mg/dL (78 vs 67 or 54%).

CONCLUSIONS

Sibling HDL-C levels, LDL-C levels, and BMIs correlate within a family. Triglyceride and blood pressure levels are less well correlated. The identified CMRF relationships strengthen the main findings of the overall CARDIAC Project: an elevated BMI is not predictive of elevated LDL-C and family history of coronary artery disease poorly predicts cholesterol abnormality at screening. Family history does not adequately identify children who should be screened for cholesterol abnormality. Elevated LDL-C (>160 mg/dL) in a child strongly suggests that additional siblings and parents be screened if universal screening is not practiced.

Cardiac and Vascular Target Organ Damage in Pediatric Hypertension

Atherosclerosis begins in youth and is associated with the presence of numerous modifiable cardiovascular (CV) risk factors, including hypertension. Pediatric hypertension has increased in prevalence since the 1980s but has plateaued in recent years. Elevated blood pressure levels are associated with impairments to cardiac and vascular structure and both systolic and diastolic function. Blood pressure-related increases in left ventricular mass (LVM) and abnormalities in cardiac function are associated with hard CV events in adulthood. In addition to cardiac changes, key vascular changes occur in hypertensive youth and adults. These include thickening of the arteries, increased arterial stiffness, and decreased endothelial function. This review summarizes the epidemiologic burden of pediatric hypertension, its associations with target organ damage (TOD) of the cardiac and vascular systems, and the impact of these adverse CV changes on morbidity and mortality in adulthood.

New Markers in Atherosclerosis: Thrombospondin-2 (THBS-2) and Leukocyte Cell-Derived Chemotaxin-2 (LECT-2); An Immunohistochemical Study

BACKGROUND Current research investigating the role of THBS2 and LECT-2 in atherogenesis is very limited. Therefore, we designed this study to demonstrate the role of THBS-2 and LECT-2 in atherosclerosis at the tissue level in fresh specimens. MATERIAL AND METHODS A total of 32 patients who underwent coronary bypass surgery were enrolled. Aortic wall punch biopsies were obtained at the site of proximal aortosaphenous bypass graft anastomosis. A specimen of left internal mammarian artery (LiMA) was taken from the segment just proximal to its anastomosis. The aortic tissue is representive of the atherosclerotic tisue, and LiMA tissue is representative of the non-atherosclerotic area. The specimens were painted with CD68 for macrophage, and THBS-2 and LECT-2 antibodies for immunohistochemical staining. RESULTS Aortic THBS-2 levels were significantly lower, whereas aortic LECT-2 levels were significantly higher when compare to LiMA (14.4±9.9 (5-30) and 36.9±13.0 (5-60) p: 0.0001 and 20.3±15.0 (5-60) and 20.8±13,8 (10-30) p: 0.0001, respectively). CD68+ and monocyte level correlated significantly with AHA atherosclerosis grade (p=0.01, r=0.45 and p=0.001, r=0.56, Spearman's test). CD68+ level correlated significantly with LECT-2 levels in atherosclerotic aortic tissue (p=0.026, r=0.392, Spearman's test), whereas aortic TSBN-2 levels were not. CONCLUSIONS The present study has taken the first steps to highlight new markers in atherosclerosis by using immunohistochemical method. The study results suggest that the tissue levels of THBS2 and LECT-2 may correlate with the stage of atherosclerosis.

Association of Dietary Factors with Progression of AA in Stroke/TIA Patients

OBJECTIVE

To investigate the effect of dietary factors such as calorie intake and dietary fats on the progression of aortic arch atheroma (AA).

BACKGROUND

In stroke/TIA patients, progression of AA is associated with recurrent vascular events.

DESIGN/METHODS

Consecutive patients with measurable (>1 mm) AA atheroma on baseline transesophageal echocardiogram (TEE) evaluation consented to a protocol mandated follow-up TEE at 12 months. Patients that had adequate paired AA images were assessed for progression, defined as Δ ≥ 1 grade worsening (based on plaque thickness over 12 months). Stroke risk factors and fasting lipid profile were assessed at baseline. The patient's nutritional intake was measured at baseline using the Gladys Block Food Frequency Questionnaire.

RESULTS

One-hundred-nine patients (70 strokes, 33 TIAs) had sequential TEEs, of whom 27% (N=30) progressed and 73% (N=79) did not. Patients with progression had higher daily calorie (1778 ± 623 vs. 1378 ± 406 Calories, p=0.008), fat (76 ± 33 vs. 52 ± 23 grams, p=0.0002), carbohydrate (208 ± 78 vs. 169 ± 57 grams, p=0.01) and protein (73 ± 26 vs. 57 ± 21 grams, p=0.005) intake. On Further analysis among different fats showed a higher consumption of saturated fats (25 ± 12 vs. 17 ±8 grams, p=0.00051) as well as unsaturated fats (44 ± 20 vs. 30 ± 13 grams, p=0.002). These differences remained significant after we adjusted for the medication use. However the significance of these differences was attenuated after adjusting for the calorie intake. Cholesterol consumption did not differ between the progression and no-progression group (262 ± 125 vs. 213 ± 149 mg, p=0.2).

CONCLUSIONS/RELEVANCE

Calorie intake plays a significant role in the progression of AA. Further studies are needed to confirm these findings and determine the specific dietary modifications that may prevent AA progression and associated recurrent vascular events.

Comparison of mercury sphygmomanometry blood pressure readings with oscillometric and central blood pressure in predicting target organ damage in youth

OBJECTIVE

Hypertension (HT) is an important risk factor for target organ damage (TOD). New methods for measuring BP are replacing mercury sphygmomanometry in many clinics. We examined the utility of different BP measurement techniques in predicting subclinical TOD in adolescents and young adults.

METHODS

Participants in a study of the cardiovascular effects of obesity and type 2 diabetes were evaluated (N=677, 18±3.3 years, 35% male, 60% non-White, 30% with type 2 diabetes). We measured adiposity, laboratory data, left ventricular mass, carotid intima-media thickness, and pulse wave velocity. BP was measured three times by mercury sphygmomanometry (BPm), using an oscillometric device (BPo), and by arterial tonometry to measure central aortic BP (BPc). Participants were stratified as normotensive, prehypertensive, or hypertensive.

RESULTS

The prevalence of HT in this cohort with a mean BMI of 31 was the highest on BPo measurement (16%), followed by BPm (11%) and BPc (9%; P≤0.001) measurements. BPm was the most consistent in differentiating left ventricular mass and pulse wave velocity among participants in the prehypertensive group as compared with the normotensive and hypertensive groups. Mercury BP measurement was also more sensitive and specific at predicting greater left ventricular mass, pulse wave velocity, and carotid thickness compared with other BP measurement techniques in logistic regression.

CONCLUSION

We conclude that mercury sphygmomanometry should remain the gold standard for evaluation of HT and the risk for TOD in adolescents and young adults.

Genetic network identifies novel pathways contributing to atherosclerosis susceptibility in the innominate artery

Background

Atherosclerosis, the underlying cause of cardiovascular disease, results from both genetic and environmental factors.

Methods

In the current study we take a systems-based approach using weighted gene co-expression analysis to identify a candidate pathway of genes related to atherosclerosis. Bioinformatic analyses are performed to identify candidate genes and interactions and several novel genes are characterized using in-vitro studies.

Results

We identify 1 coexpression module associated with innominate artery atherosclerosis that is also enriched for inflammatory and macrophage gene signatures. Using a series of bioinformatics analysis, we further prioritize the genes in this pathway and identify Cd44 as a critical mediator of the atherosclerosis. We validate our predictions generated by the network analysis using Cd44 knockout mice.

Conclusion

These results indicate that alterations in Cd44 expression mediate inflammation through a complex transcriptional network involving a number of previously uncharacterized genes.

Negative associations between arterial stiffness parameter evaluated by cardio-ankle vascular index and serum low-density lipoprotein cholesterol concentration in early-stage atherosclerosis

The cardio-ankle vascular index (CAVI), calculated values from cardio-ankle pulse wave velocity and blood pressure, corresponds predominantly to the stiffness of the aorta and peripheral arteries of the lower limbs. However, the reported associations between CAVI and serum low-density lipoprotein cholesterol (LDL-C) levels remain inconsistent. A cross-sectional study of 1878 consecutive patients (mean age: 59.2 years) who underwent general health checkup showed a negative association between CAVI and serum LDL-C or non-high-density lipoprotein cholesterol (non-HDL-C) concentrations with age-adjusted correlation and multiple regression analysis. Using the similar analyses divided by the status of risk factors and degree of maximum carotid intima-media thickness (maxIMT), negative correlations between CAVI and LDL-C or non-HDL-C levels were observed only in nonrisk groups including nondiabetics patients or patients with maxIMT <1.0 mm, in those with expected low extent of advanced atherosclerotic lesions. In contrast, such a correlation was not found in each comparable risk-loaded group.

Inflammation in young adulthood is associated with myocardial infarction later in life

BACKGROUND

There is evidence that atherosclerosis begins in childhood. There is also evidence that inflammatory markers measured in middle and old age predict risks of cardiovascular disease. In this report, we test whether an inflammatory marker measured in young adult men is associated with risk of myocardial infarction in middle age.

METHODS

During Swedish national conscription tests from 1969 through 1978, the erythrocyte sedimentation rate, as a measure of inflammation, was measured in 433,577 young Swedish men. The cohort was observed for subsequent myocardial infarction events through December 2009.

RESULTS

During an average follow-up time of 35 years, a total of 8,081 first-time myocardial infarctions occurred within the cohort. After adjustments for potential confounders and known risk factors for myocardial infarction, men with an elevated erythrocyte sedimentation rate (≥15 mm/h) had a 1.7 times increased risk of myocardial infarction during follow-up (95% CI 1.4-2.1) compared with men with an erythrocyte sedimentation rate of 1 mm/h. This relationship was dose dependent for each unit increase in erythrocyte sedimentation rate (P for trend < .001).

CONCLUSIONS

In this cohort of young Swedish men, the erythrocyte sedimentation rate was associated with risk of myocardial infarction 35 years later after control of the available data on other coronary risk factors. These data add important relevant information to the existing evidence that atherosclerosis begins in childhood.

Histological changes and risk factor associations in type 2 atherosclerotic lesions (fatty streaks) in young adults

OBJECTIVES

The purpose of this study was to investigate which histological changes associated with risk factors could contribute to the progression from the initial atherosclerotic lesions including fatty streaks to the advanced lesions.

METHODS

We examined the associations of histomorphometric findings in the determined anatomical sites of mid-thoracic aortas (TAs) and left anterior descending coronary arteries (LADs) with major risk factors for atherosclerosis, using a young autopsied series from the the Pathobiological Determinants of Atherosclerosis in Youth (PDAY) study. The histological classification by the American Heart Association was graded for 1013 TAs and 1009 LADs. Histometric study, including immunohistochemistry, was performed in type 2 lesions (fatty streaks) of TAs from 59 subjects and LADs from 45 ones.

RESULTS

For the progression from the initial lesions into the advanced atherosclerotic lesions, the most effective lipid profiles were low plasma HDL-C in TA and elevated serum non-HDL-C in LAD. This lipid profile of each artery correlated with number or density of intimal smooth muscle cell-derived foam cells, respectively. The serum concentration of non-HDL-C correlated with macrophage foam cells in TAs. Hypertension and hyperglycemia were associated with increase of intimal area and/or collagen content in both arteries, but not with either types of foam cell proliferation. Smoking correlated with increased collagen content in TAs.

CONCLUSION

There were histologically different ways of progressing from fatty streaks to advanced atherosclerotic lesions depending on the risk factors. For the atherosclerosis progression from type 2 lesions to advanced lesions, increase in number of smooth muscle cell-derived foam cells could be an important indicator.

Assessment and management of hypertension in children and adolescents

The epidemic of overweight and obesity in youth is increasing the prevalence of prehypertension and hypertension among children and adolescents. The younger the child is at presentation and the more severe the blood pressure abnormality, the more likely a secondary cause of hypertension is to be present. Measurement of blood pressure in children requires adaptation to the age and size of the child. Interpretation must be related to normative values specific for age, sex, and height. Evaluation is primarily aimed at identifying secondary causes of hypertension, associated comorbidities, additional risk factors, and evidence of target-organ damage. Ambulatory blood pressure monitoring is emerging as a useful tool for evaluation of some patients, particularly for those with suspected 'white coat' hypertension. Management of prehypertension and hypertension is directed at the underlying cause, exacerbating factors, and the magnitude of the blood pressure abnormality. Healthy behavioral changes are a primary management tool for treating hypertension and, more particularly, prehypertension and for addressing other cardiovascular risk factors, such as obesity. Pharmacological management is reserved for patients with hypertension who do not respond to behavioral changes, have additional cardiovascular risk factors or diabetes, are symptomatic, or have developed target-organ damage.

Association of Leukocyte Count With Progression of Aortic Atheroma in Stroke/Transient Ischemic Attack Patients

Background and Purpose— Leukocyte count is an independent predictor of stroke. We investigated the association between leukocyte count and progression of aortic atheroma over 12 months in stroke/transient ischemic attack (TIA) patients.

Methods— Consecutive ischemic stroke and transient ischemic attack patients underwent 12-month sequential transesophageal echocardiography and were assessed for total and differential leukocyte counts on admission. Paired aortic plaque images were assessed for several parameters, including changes in grade, intimal-medial thickness (IMT), and cross-sectional area. Multivariate linear and logistic regressions were used to calculate the effect of leukocyte count on the change in aortic atheromas over 12 months.

Results— Of the 115 participants (mean±SD age, 64.6±11.9 years; 53.1% men; 73.4% white, 24.2% black, and 2.3% Asian), 45 (35%) showed clinically significant progression of aortic atheromas (maximal change in IMT >0.70 mm over 12 months). The mean admission leukocyte count was higher in the progression group compared with the no-progression group (8.6±2.2 vs 7.3±2.2×10 9 /L respectively, P =0.002). Each unit increase in leukocyte count was associated with a 0.26-mm increase in aortic arch IMT over 12 months ( P =0.006). After adjustment for other atherosclerosis risk factors, the relation persisted (mean increase in aortic arch IMT per unit increase in leukocyte count=0.27 mm, P =0.007). Each unit increase in leukocyte count was associated with an increased risk of significant progression of aortic atheromas (adjusted odds ratio=1.33; 95% CI, 1.09 to 1.61).

Conclusions— In stroke/transient ischemic attack patients, leukocyte count is independently associated with the progression of aortic atheroma over 12 months (>0.70 mm), which is associated with cardiovascular risk.

Histological topographical comparisons of atherosclerosis progression in juveniles and young adults

BACKGROUND

The histologically topographic comparisons on atherosclerosis progression among three anatomical sites, mid-thoracic and lower abdominal aorta and left anterior descending coronary artery (LAD) were performed using a young population (age 15-34 years) from the Pathobiological Determinants of Atherosclerosis in Youth (PDAY) study.

METHODS AND RESULTS

The histological classification based on the American Heart Association grading scheme showed that in the thoracic aorta type 2 lesions (numerous macrophage foam cells with fine particles but no pools of extracellular lipid) appeared in the first 10-year age group, with no significant change in prevalence in the next 10 years. Lesions greater than type 2 were rarely seen in the thoracic aorta. Although type 2 lesions appeared later in the LAD than in the aorta, the lesions within the LAD progressed rapidly to more advanced lesions (types 4 and 5) or atheroma. Lesion development in the abdominal aorta was intermediate to lesion development in the thoracic aorta and the LAD.

CONCLUSIONS

The most striking topographic difference on lesion progression among the three anatomical sites was the vulnerability of type 2 lesions to progress into advanced lesions. The histology study, including immunohistochemistry limited to the type 2 lesions suggested that lesion progression was related to the intimal thickness and the amount of collagen but not to the number of macrophage foam cells.

Arterial endothelial function in a porcine model of early stage atherosclerotic vascular disease

Cardiovascular disease (CVD) is the leading cause of morbidity and mortality in the United States and is projected to become the leading cause of mortality in the world. Atherosclerosis is the most important single factor contributing to this disease burden. In this study, we characterize relationships between endothelial dysfunction and vascular disease in an animal model of diet-induced, early-stage atherosclerotic vascular disease. We tested the hypothesis that hypercholesterolaemia induces vascular disease and impairs endothelium-dependent relaxation (EDR) in conduit arteries of adult male Yucatan pigs. Pigs were fed a normal fat (NF) or high fat cholesterol (HFC) diet for 20-24 weeks. Results indicate that, while the HFC diet did not alter EDR in femoral or brachial arteries, EDR was significantly decreased in both carotid and coronary arteries. Sudanophilic fatty streaks were significantly present in the abdominal aorta and common carotid artery. Histopathology revealed increased intima-media thickness (IMT) and foam cell accumulation in Stary Stage I-III lesions in the abdominal aorta, common carotid artery and femoral arteries. In the coronary arteries, the accumulation of foam cells in Stary Stage I and II lesions resulted in a trend for increased IMT. There was no evidence of vascular disease in the brachial arteries. These results indicate that early stages of CVD (Stary Stage I-III) precede decreases in EDR induced by HFC diet, because femoral arteries exhibited foam cell accumulation and an increased IMT but no change in endothelial function.

Body mass index and high-density lipoproteins in Cherokee Indian children and adolescents

Native Americans are predisposed to insulin resistance and associated cardiovascular risk. Therefore, we studied whether BMI (body mass index) in a population of Cherokee children and adolescents is associated with HDL-C (HDL cholesterol), and the HDL particles Lp (lipoprotein) A-I and LpA-I:A-II. Subjects were grouped by BMI Z score quartiles within three gender-specific age brackets (5-9, 10-14, and 15-19 y) to examine for trends in lipoprotein and HOMA-IR (homeostasis index insulin resistance) values associated with adiposity and age. HDL-C decreased by BMI Z score quartiles in all three age groups for both genders. HDL-C, LpA-I, and LpA-I:A-II decreased with age in boys but not girls. Log HOMA-IR increased by BMI Z score quartiles in all three age groups for both genders. Linear regression modeling showed BMI Z score, triglyceride, and age to be associated with HDL-C, whereas HOMA-IR was associated with LpA-I:A-II but not with HDL-C or LpA-I. When waist circumference was substituted for BMI Z score in the same models, it was associated with HDL-C and both lipoprotein particles. In conclusion, adiposity is more associated with HDL-C lowering than with declines in the lipoprotein particles. HOMA-IR is less associated with HDL-C but may selectively influence LpA-I:A-II. Greater decreases in HDL-C, LpA-I, and LpA-I:A-II with age in boys is attributed to gender-specific hormonal changes. The early onset of HDL lowering in these Native American children and adolescents, particularly boys, warrants intervention strategies to prevent obesity and associated cardiovascular risk.

Leukocyte count is associated with aortic arch plaque thickness

BACKGROUND AND PURPOSE

Leukocyte count has been associated with cardiovascular and cerebrovascular disease, including carotid plaque thickness, in several studies. We hypothesized that white blood cell count is associated with aortic arch plaque thickness (AAPT).

METHODS

Leukocyte count was measured in randomly selected stroke-free community participants undergoing transesophageal echocardiography. AAPT was measured for each subject and dichotomized into <4 and > or =4 mm (thick plaque). Multivariate linear and logistic regression was used to calculate the effect of leukocyte count on AAPT after adjustment for potential confounding factors. Mean age of the 145 participants was 68.5+/-8.3 years; 43.5% were women; 15.9% were white; 31.7% were black; and 49.0% were Hispanic.

RESULTS

Mean leukocyte count was 5.88+/-1.76x10(9)/L. Each unit increase in leukocyte count was associated with a mean 0.28-mm increase in AAPT (P=0.0036). After adjustment for other atherosclerosis risk factors, including age, sex, hypertension, diabetes, hyperlipidemia, and smoking, the relationship persisted (mean increase in AAPT, 0.24 mm; P=0.0064). Thirty-five participants (24.1%) had AAPT > or =4 mm. Mean leukocyte count among those with thick plaque was significantly higher than among those with plaque <4 mm (6.54+/-1.60 versus 5.65+/-1.76x10(9)/L, respectively; P=0.009). Each unit increase in leukocyte count was associated with an increased risk of thick plaque (adjusted odds ratio, 1.38; 95% CI, 1.05 to 1.79). The relationships were similar for men and women and for those <70 or > or =70 years of age.

CONCLUSIONS

Leukocyte count is associated with AAPT and is specifically correlated with AAPT > or =4 mm, a degree of thickening associated with increased stroke risk. These findings are consistent with current hypotheses regarding the inflammatory or infectious etiology of risk of atherosclerosis and stroke.