Mediation of cardiovascular risk factor effects through subclinical vascular disease: the Multi-Ethnic Study of Atherosclerosis

Changes in fasting plasma glucose and subclinical atherosclerosis: A cohort study from VIPVIZA trial

BACKGROUND AND AIMS

Studies on the influence of fasting plasma glucose (FPG) on the development of carotid plaque (CP) and intima media thickness (CIMT) mainly focused on single FPG measures. We investigated whether changes in FPG (ΔFPG) are associated with incident CP and CIMT change (ΔCIMT) over time.

METHODS

Analyses were based on information from 1896 participants from the VIPVIZA trial (Visualization of asymptomatic atherosclerotic disease for optimum cardiovascular prevention), with baseline and 3-year follow-up data on FPG, ultrasonographic CP (none or ≥1 lesion/s) and CIMT assessments. We studied the association between baseline FPG (prior to intervention) or 3-year ΔFPG (mmol/L) and incident CP (logistic regression) or ΔCIMT (linear regression). Analyses were adjusted for multiple potential confounders.

RESULTS

1896 and 873 individuals, respectively, were included in the analysis on incident CP and ΔCIMT. Participants were 60 years old at baseline and 61% and 54% were females, in the CP and CIMT analyses, respectively. Every mmol/L increase in FPG was associated with an increased odds of incident CP (odds ratio: 1.42, 95% confidence interval [CI]: 1.17, 1.73), but there was no association with ΔCIMT (mean difference: 0.002 mm, 95% CI: -0.003, 0.008) after 3 years. Baseline FPG was not associated with incident CP nor ΔCIMT progression.

CONCLUSIONS

In middle-aged individuals with low to moderate risk for cardiovascular diseases, 3-year ΔFPG was positively associated with the risk of incident CP, but not with ΔCIMT. Single measures of FPG may not be sufficient in estimating cardiovascular risk among individuals with low to moderate risk.

Subclinical cardiovascular disease and utility of coronary artery calcium score

ASCVD are the leading causes of mortality and morbidity among Globe. Evaluation of patients' comprehensive and personalized risk provides risk management strategies and preventive interventions to achieve gain for patients. Framingham Risk Score (FRS) and Systemic Coronary Risk Evaluation Score (SCORE) are two well studied risk scoring models, however, can miss some (20-35%) of future cardiovascular events. To obtain more accurate risk assessment recalibrating risk models through utilizing novel risk markers have been studied in last 3 decades and both ESC and AHA recommends assessing Family History, hs-CRP, CACS, ABI, and CIMT. Subclinical Cardiovascular Disease (SCVD) has been conceptually developed for investigating gradually progressing asymptomatic development of atherosclerosis and among these novel risk markers it has been well established by literature that CACS having highest improvement in risk assessment. This review study mainly selectively discussing studies with CACS measurement. A CACS = 0 can down-stratify risk of patients otherwise treated or treatment eligible before test and can reduce unnecessary interventions and cost, whereas CACS ≥ 100 is equivalent to statin treatment threshold of ≥ 7.5% risk level otherwise statin ineligible before test. Since inflammation, insulin resistance, oxidative stress, dyslipidemia and ongoing endothelial damage due to hypertension could lead to CAC, ASCVD linked with comorbidities. Recent cohort studies have shown a CACS 100-300 as a sign of increased cancer risk. Physical activity, dietary factors, cigarette use, alcohol consumption, metabolic health, family history of CHD, aging, exposures of neighborhood environment and non-cardiovascular comorbidities can determine CACs changes.

Genetic variation implicates plasma angiopoietin-2 in the development of acute kidney injury sub-phenotypes

BACKGROUND

We previously identified two acute kidney injury (AKI) sub-phenotypes (AKI-SP1 and AKI-SP2) with different risk of poor clinical outcomes and response to vasopressor therapy. Plasma biomarkers of endothelial dysfunction (tumor necrosis factor receptor-1, angiopoietin-1 and 2) differentiated the AKI sub-phenotypes. However, it is unknown whether these biomarkers are simply markers or causal mediators in the development of AKI sub-phenotypes.

METHODS

We tested for associations between single-nucleotide polymorphisms within the Angiopoietin-1, Angiopoietin-2, and Tumor Necrosis Factor Receptor 1A genes and AKI- SP2 in 421 critically ill subjects of European ancestry. Top performing single-nucleotide polymorphisms (FDR < 0.05) were tested for cis-biomarker expression and whether genetic risk for AKI-SP2 is mediated through circulating biomarkers. We also completed in vitro studies using human kidney microvascular endothelial cells. Finally, we calculated the renal clearance of plasma biomarkers using 20 different timed urine collections.

RESULTS

A genetic variant, rs2920656C > T, near ANGPT2 was associated with reduced risk of AKI-SP2 (odds ratio, 0.45; 95% CI, 0.31-0.66; adjusted FDR = 0.003) and decreased plasma angiopoietin-2 (p = 0.002). Causal inference analysis showed that for each minor allele (T) the risk of developing AKI-SP2 decreases by 16%. Plasma angiopoietin-2 mediated 41.5% of the rs2920656 related risk for AKI-SP2. Human kidney microvascular endothelial cells carrying the T allele of rs2920656 produced numerically lower levels of angiopoietin-2 although this was not statistically significant (p = 0.07). Finally, analyses demonstrated that angiopoietin-2 is minimally renally cleared in critically ill subjects.

CONCLUSION

Genetic mediation analysis provides supportive evidence that angiopoietin-2 plays a causal role in risk for AKI-SP2.

Three Dimensional Carotid and Femoral Ultrasound is not Superior to Two Dimensional Ultrasound as a Predictor of Coronary Atherosclerosis Among Men With Intermediate Cardiovascular Risk

BACKGROUND

Current cardiovascular disease (CVD) risk stratification scales, drawn up from traditional risk factors, have important limitations. The detection of subclinical atherosclerosis, by a non-invasive technique such as peripheral arteries ultrasound (US) may improve cardiovascular risk (CVR) stratification, especially in intermediate risk population. Our aim was to compare the predictive power of atherosclerotic plaques detected in carotid and femoral arteries by 2-dimensional (2D) vs. 3-dimensional (3D) US for positive coronary artery calcium score (CACS), used as a proxy for CVD, in a middle-aged sample with intermediate 10-year CVR (7.5-20%).

METHODS

To detect atherosclerotic plaques by 2D vs. 3D US scan of carotid and femoral arteries and comparison of their association with CACS obtained by computed tomography (CT) of subjects with intermediate CVR belonging to the Aragon Workers' Health Study.

RESULTS

120 men were included, with a 10.4% average 10 years CVR. Forty-one (34.2%) participants had CACS ≥ 1. 90 participants (75%) had at least one plaque detected by 2D scan while 85 participants (70.8%) had at least a plaque detected by 3D US. Conventional CVR estimates c-statistic for CACS was .590. Although the variables most predicted of CACS ≥ 1 were those measured by 3D US (total plaque volume and mean of plaque density, c-statistics: .743 and .750 respectively), their predictive capacity was not statistically significantly different from the number of territories with plaque, measured either by 2D and 3D US (c-statistics .728 to .740 respectively).

CONCLUSION

Subclinical atherosclerosis measured by 2D and 3D US were better predictors of CACS ≥ 1 than CVR estimated by conventional guidelines. In our sample, 3D US did not show any significant advantages with respect to 2D US for the prediction of coronary atherosclerosis.

Epicardial Fat Volume Improves the Prediction of Obstructive Coronary Artery Disease Above Traditional Risk Factors and Coronary Calcium Score

BACKGROUND

Recent studies have demonstrated the tremendous potential of epicardial fat volume (EFV) to predict obstructive coronary artery disease. We aimed to develop a new model to estimate pretest probability of obstructive coronary artery disease using traditional risk factors with coronary calcium score and EFV and compare it with proposed models in Chinese patients who underwent coronary computed tomography angiography.

METHODS

The new models were derived from 5743 consecutive patients using multivariate logistic regression and validated in an internal cohort using invasive coronary angiography as the outcome and an external cohort with clinical outcome data. Hosmer-Lemeshow goodness-of-fit test, area under the receiver operating characteristic curve, integrated discrimination improvement and net reclassification improvement were calculated to validate and compare the performance of models.

RESULTS

EFV improved prediction above conventional risk factors and coronary calcium score (area under the receiver operating characteristic curve increased from 0.856 to 0.874, integrated discrimination improvement 0.0487, net reclassification improvement 0.1181, P<0.0001 for all). The final model included 5 predictors: age, sex, symptom, coronary calcium score, and EFV. Good internal validation and external validation of the new model were achieved, with positive net reclassification improvement and integrated discrimination improvement, excellent area under the receiver operating characteristic curve and favorable calibration. Further, the new model demonstrated a better prediction of clinical outcome, resulting in a more cost-effective risk stratification to optimize decision-making of downstream diagnosis and treatment.

CONCLUSIONS

Addition of EFV to conventional risk factors and coronary calcium score offered a more accurate and effective estimation for pretest probability of obstructive coronary artery disease, which may help to improve initial management of stable chest pain.

Pretransplant Cardiac Evaluation Using Novel Technology

Hematopoietic stem-cell transplantation (HSCT) is a complex procedure that has been increasingly successful in treating malignant and nonmalignant conditions. Despite its effectiveness, it can be associated with potentially life-threatening adverse effects. New onset heart failure, ischemic disease, and arrhythmias are among the most notable cardiovascular complications post-HSCT. As a result, appropriate cardiac risk stratification prior to transplant could result in decreased morbidity and mortality by identifying patients with a higher probability of tolerating possible toxicities associated with HSCT. In this review, we aim to discuss the utility of cardiac screening using novel modalities of imaging technology in the pre-HSCT phase.

Cardiovascular Risk Factors Accelerate Progression of Vascular Aging in the General Population: Results From the CRAVE Study (Cardiovascular Risk Factors Affecting Vascular Age)

Vascular aging, as assessed by structural and functional arterial properties, is an independent predictor of cardiovascular risk. We hypothesized that the number of cardiovascular risk factors determines the progression of vascular aging. One hundred forty-two subjects (mean age 51.9 years, 94 men) without established cardiovascular disease were investigated in 2 examinations over a 2-year period. Subjects were classified at baseline according to their number of risk factors (from 0 to 2 and more). Subjects had determinations of carotid-femoral pulse wave velocity, aortic augmentation index, brachial flow-mediated dilatation, and common carotid intima-media thickness and their annual absolute changes were calculated. Subjects with more risk factors had a gradual higher annual progression of pulse wave velocity (0.092 m/s/y for 0, 0.152 m/s/y for 1, and 0.352 m/s/y for 2 and more; P=0.007). Patients with both hypertension and dyslipidemia have 4× higher annual progression rate compared with subjects without these risk factors (0.398 m/s/y versus 0.102 m/s/y). When only subjects 55 years old and under were considered, the progression rate of augmentation index was higher in subjects with more risk factors (1.15%/y versus 1.50%/y versus 2.99%/y, respectively; P=0.037). No association was found with the annual change of flow-mediated dilatation or carotid intima-media thickness. In the general population, increasing number of risk factors is associated with accelerated deterioration of specific indices of vascular aging, such as pulse wave velocity and augmentation index; in contrast, flow-mediated dilatation and carotid intima-media thickness are insensitive to such changes. Accordingly, the former may be more useful for gauging vascular aging.

Adiposity during adolescence and carotid intima-media thickness in adulthood: Results from the 1993 Pelotas Birth Cohort

Background and aims

Although several studies have examined the association between adiposity and cardiovascular risk markers, few have explored the issue prospectively in young populations. We sought to test whether higher levels of body mass index (BMI) and subscapular skinfold at different stages of adolescence were associated with carotid intima-media thickness (cIMT) in young adulthood.

Methods

In a prospective cohort, we assessed BMI and subscapular skinfold at 11, 15 and 18 years and measured cIMT at 18 years in 3264 individuals. Traditional cardiovascular risk factors and fat mass-mediating effects on cIMT were also assessed.

Results

Both BMI and subscapular skinfolds were significantly associated with higher cIMT in a cummulative fashion: after controlling for confounders, males and females who persisted overweight/obese at all three assessments, had a mean higher cIMT (5.2 and 3.1 μm, respectively) compared to males and females with normal/healthy BMI at each evaluation (p < 0.001). Moreover, male and females that presented increased fatness in all assessments had a similar pattern of higher cIMT compared to normal/healthy fatness/skinfold at 18 years (mean cIMT 4.6 and 3.0 μm for males and females, respectively; p < 0.001). Associations between adiposity and cIMT were both direct and indirect. Indirect effects were chiefly mediated by fat mass and diastolic blood pressure.

Conclusions

Our results suggest adiposity exerts direct and indirect effects during adolescence that result in higher cIMT in young adulthood.

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High BMI and subscapular skinfolds during adolescence are associated with higher cIMT at 18 years.

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Adiposity exerts direct and indirect effects on cIMT.

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Indirect effects are chiefly mediated by fat mass and diastolic blood pressure.

Diabetes and Clinical and Subclinical CVD

Diabetes mellitus is a major cardiovascular risk factor and its prevalence has been increasing globally. This review examines the contributions of the MESA (Multi-Ethnic Study of Atherosclerosis), a diverse American cohort (6,814 adults ages 45 to 84, recruited from 2000 to 2002, 50% female, 62% nonwhite) toward understanding the relationship between diabetes and clinical and subclinical cardiovascular disease. People with diabetes have a high burden of subclinical vascular disease as measured by coronary artery calcification (CAC), carotid artery intima-media thickness, valvular calcification, and alterations in left ventricular structure. CAC substantially improves cardiovascular risk prediction. Among adults with diabetes, 63% had CAC >0; above CAC >400 Agatston units the event rate was 4% annually, whereas an absence of CAC was a marker of a very low cardiovascular disease rate (0.4% to 0.1% annually). These stark differences in rates may have implications for screening and/or targeted prevention efforts based on CAC burden. MESA has also provided insight on diabetes epidemiology.

Serum Immune Mediators Independently Associate with Atherosclerosis in the Left (But Not Right) Carotid Territory of Older Individuals

BACKGROUND AND AIM

Disturbance in the carotid arteries strongly predicts cerebrovascular events and correlates with a systemic inflammatory milieu. We investigated the relationship of a profile of 10 circulating inflammatory mediators with measures of carotid intima-media thickness (cIMT) in elderly subjects, taking traditional risk factors into account.

METHODS

Clinical inspection for present and past chronic conditions and events, as well as biochemical and anthropometric measurements, was performed for patients in ambulatory setting. Scores of cIMT were obtained bilaterally in the distal common carotid artery wall. Serum concentrations of cytokines were assessed by bead-based, multiplexed flow cytometry immunoassays.

RESULTS

Correlation analysis between log-transformed cytokines levels implicated the mediators interleukin-1β (IL1β), IL6, IL8, IL10, and tumor necrosis factor-α (TNFα) (P ≤ .005) with scores of the left cIMT. Stepwise multivariate regression showed that TNFα, IL1β, and IL6 levels accounted for most of the variance in the cIMT scores. Comparison of cytokine levels across increasing tertiles of the left cIMT reproduced the positive association with TNFα and IL1β levels.

CONCLUSION

Five out of ten immune mediators independently correlated with cIMT of older subjects in a territory-sensitive manner. This possible contribution of immune mediators to an atherosclerotic process probably relates to the inflammaging process.

Hepatic fat content is a determinant of metabolic phenotypes and increased carotid intima-media thickness in obese adults

Individuals with metabolically healthy obesity (MHO) are at relatively low risk for the development of metabolic abnormalities and subclinical atherosclerosis. This study aims to examine whether hepatic fat accumulation determines metabolic phenotype of obesity and associated with subclinical atherosclerosis. A total of 485 obese adults (aged 40–65 years) who received magnetic resonance spectroscopy were divided into metabolically abnormally obesity (MAO) and MHO groups according to metabolic status. MHO individuals had lower levels of intrahepatic triglyceride (IHTG) content and carotid intima-media thickness (CIMT) than MAO individuals. In multivariable linear regression analyses, IHTG content was independently associated with metabolic syndrome components and CIMT. Based on receiver operating characteristic curve analysis, the IHTG content displayed a higher area under the curve (AUC) for detecting the MAO phenotype (AUC = 0.70, 95%CI = 0.65–0.75) and increased CIMT (AUC = 0.60, 95%CI = 0.54–0.66) than BMI, waist circumference, and body fat percent. MHO individuals were 1.9 times (p < 0.001) more likely to have metabolic syndrome per 1 SD change in IHTG content in multivariable-adjusted models. Likewise, the risk for high CIMT increased 29% per 1 SD change in IHTG content [OR (95% CI):1.29(1.01–1.64)]. These findings suggest that hepatic fat is a potential predictor of metabolically unhealthy obesity phenotype and subclinical atherosclerosis.

Circulating osteoprotegerin is increased in the metabolic syndrome and associates with subclinical atherosclerosis and coronary arterial calcification

CONTEXT

The relationship between osteoprotegerin (OPG) a glycoprotein related to bone metabolism and the metabolic syndrome (MS) has not been established.

OBJECTIVE

The aim of this study is to evaluate OPG concentration in patients with MS and its association with subclinical atherosclerosis and coronary arterial calcification (CAC).

MATERIALS/METHODS

The study included 238 asymptomatic patients. MS was diagnosed according to the NCEP/ATPIII guidelines. OPG was measured by ELISA. All subjects underwent ultrasonography of the common carotid arteries to measure intima-media thickness (IMT) and evaluate the presence of atheroma plaques. In a subgroup (n=39) CAC was quantified by ECG-triggered cardiac computed tomography. Adipose tissue was excised from 25 patients and OPG expression by RT-PCR and immunohistochemistry was studied.

RESULTS

Patients with the MS (n=60) had higher OPG than patients without (n=178) (p<0.05). OPG correlated with IMT (r=0.2, p=0.005) and patients with atheroma plaques had higher OPG (p=0.008) and also those with coronary artery calcification (p<0.05). OPG expression was confirmed in adipose tissue (n=12) and the expression was significantly higher in patients with MS than in those without (p=0.003).

CONCLUSIONS

This study shows that OPG may potentially be a biomarker for cardiovascular risk/damage in the MS and identifies adipose tissue as a potential source of OPG.