227 research outputs found

    Risk Factors for Long-Term Coronary Artery Calcium Progression in the Multi-Ethnic Study of Atherosclerosis.

    Get PDF
    BackgroundCoronary artery calcium (CAC) detected by noncontrast cardiac computed tomography scanning is a measure of coronary atherosclerosis burden. Increasing CAC levels have been strongly associated with increased coronary events. Prior studies of cardiovascular disease risk factors and CAC progression have been limited by short follow-up or restricted to patients with advanced disease.Methods and resultsWe examined cardiovascular disease risk factors and CAC progression in a prospective multiethnic cohort study. CAC was measured 1 to 4 times (mean 2.5 scans) over 10 years in 6810 adults without preexisting cardiovascular disease. Mean CAC progression was 23.9 Agatston units/year. An innovative application of mixed-effects models investigated associations between cardiovascular disease risk factors and CAC progression. This approach adjusted for time-varying factors, was flexible with respect to follow-up time and number of observations per participant, and allowed simultaneous control of factors associated with both baseline CAC and CAC progression. Models included age, sex, study site, scanner type, and race/ethnicity. Associations were observed between CAC progression and age (14.2 Agatston units/year per 10 years [95% CI 13.0 to 15.5]), male sex (17.8 Agatston units/year [95% CI 15.3 to 20.3]), hypertension (13.8 Agatston units/year [95% CI 11.2 to 16.5]), diabetes (31.3 Agatston units/year [95% CI 27.4 to 35.3]), and other factors.ConclusionsCAC progression analyzed over 10 years of follow-up, with a novel analytical approach, demonstrated strong relationships with risk factors for incident cardiovascular events. Longitudinal CAC progression analyzed in this framework can be used to evaluate novel cardiovascular risk factors

    Importance of the lipid-related pathways in the association between statins, mortality and cardiovascular disease risk : the multi-ethnic study of atherosclerosis

    Get PDF
    PURPOSE: Estimating how much of the impact of statins on coronary heart diseases (CHD), cardiovascular disease (CVD), and mortality risk is attributable to their effect on low-density lipoprotein cholesterol (LDL), high-density lipoprotein cholesterol (HDL), and triglycerides. METHODS: A semi-parametric g-formula estimator together with data from the Multi-Ethnic Study of Atherosclerosis (a prospective multi-center cohort study) was utilized to perform a mediation analysis. A total of 5280 participants, men and women of various race/ethnicities from multiple sites across the United States, were considered in the current study. RESULTS: The adherence adjusted total relative risk reduction (RRR) estimate (95% confidence interval) of statins on CHD was 14% (-16%, 37%), and the indirect component through LDL was 23% (-4%, 58%). For CVD, the total RRR was 23% (2%, 40%), and the indirect component through LDL was 5% (-13%, 25%). The total RRR of mortality was 18% (-1%, 35%), and the indirect component through LDL was -4% (-17%, 12%). The estimated indirect components through HDL and triglycerides were close to zero with narrow confidence intervals for all 3 outcomes. CONCLUSIONS: The estimated effect of statins on mortality, CVD, and CHD appeared to be independent of their estimated effect on HDL and triglycerides. Our study provides evidence that the preventive effect of statins on CHD could be attributed in large part to their effect on LDL. Our g-formula estimator is a promising approach to elucidate pathways, even if it is hard to make firm conclusions for the LDL pathway on mortality and CV

    Net Reclassification Indices for Evaluating Risk Prediction Instruments: A Critical Review

    Get PDF
    Background Net Reclassification Indices (NRI) have recently become popular statistics for measuring the prediction increment of new biomarkers. Methods In this review, we examine the various types of NRI statistics and their correct interpretations. We evaluate the advantages and disadvantages of the NRI approach. For pre-defined risk categories, we relate NRI to existing measures of the prediction increment. We also consider statistical methodology for constructing confidence intervals for NRI statistics and evaluate the merits of NRI-based hypothesis testing. Conclusions Investigators using NRI statistics should report them separately for events (cases) and nonevents (controls). When there are two risk categories, the NRI components are the same as the changes in the true and false positive rates. We advocate use of true and false positive rates and suggest it is more useful for investigators to retain the existing, descriptive terms. When there are three or more risk categories, we recommend against NRI statistics because they do not adequately account for clinically important differences in movements among risk categories. The category-free NRI is a new descriptive device designed to avoid pre-defined risk categories. The category-free NRI suffers from many of the same problems as other measures such as the area under the receiver operating characteristic curve. In addition, the category-free NRI can mislead investigators by overstating the incremental value of a biomarker, even in independent validation data. When investigators want to test a null hypothesis of no prediction increment, the well-established tests for coefficients in the regression model are superior to the NRI. If investigators want to use NRI measures, their confidence intervals should be calculated using bootstrap methods rather than published variance formulas. The preferred single-number summary of the prediction increment is the improvement in the Net Benefit

    Higher leptin is associated with hypertension: the Multi-Ethnic Study of Atherosclerosis

    Get PDF
    Adipokines are secreted from adipose tissue, influence energy homeostasis and may contribute to the association between obesity and hypertension. Among 1897 participants enrolled in the Multi-Ethnic Study of Atherosclerosis, we examined associations between blood pressure and leptin, tumor necrosis factor-α (TNFα), resistin and total adiponectin. The mean age and body mass index (BMI) was 64.7 years and 28.1, respectively, and 50% were female. After adjustment for risk factors, a 1-s.d.-increment higher leptin level was significantly associated with higher systolic (5.0 mm Hg), diastolic (1.9), mean arterial (2.8) and pulse pressures (3.6), as well as a 34% higher odds for being hypertensive (P<0.01 for all). These associations were not materially different when the other adipokines, as well as BMI, waist circumference or waist-to-hip ratio, were additionally added to the model. Notably, the associations between leptin and hypertension were stronger in men, but were not different by race/ethnic group, BMI or smoking status. Adiponectin, resistin and TNFα were not independently associated with blood pressure or hypertension. Higher serum leptin, but not adiponectin, resistin or TNFα, is associated with higher levels of all measures of blood pressure, as well as a higher odds of hypertension, independent of risk factors, anthropometric measures and other selected adipokines

    Alcohol Type and Ideal Cardiovascular Health Among Adults of the Multi-Ethnic Study of Atherosclerosis

    Get PDF
    BACKGROUND: Light to moderate alcohol consumption is associated with favorable cardiovascular health (CVH). However, the association between alcohol type and ideal CVH has not been well-established. We examined the relationship between alcohol type and ideal CVH as measured by the American Heart Association’s seven CVH metrics. METHODS: We analyzed data from 6,389 men and women aged 45–84 years from a multi-ethnic cohort free of cardiovascular disease. Alcohol type (wine, beer and liquor) was categorized as never, former, 0 but drink other alcohol types, >0 but 2 drinks/day. A CVH score ranging from 0–14 points was created from the seven CVH metrics (Inadequate score, 0–8; average, 9–10; optimal, 11–14). We used multinomial logistic regression to examine the association between alcohol type and CVH, adjusting for age, sex, race/ethnicity, education, income, health insurance, field site and total calorie intake. RESULTS: The mean (SD) age of participants was 62 (10) years and 53% were women. Participants who consumed 1–2 drinks/day of wine had higher odds of optimal CVH scores compared to those who never drank wine [adjusted prevalence odds ratio (POR) 1.64 (1.12–2.40)]. In comparison to participants who never drank beer, those who consumed >2 drinks/day of beer had lower odds of optimal CVH scores [0.31 (0.14–0.69)]. Additionally, those who consumed >2 drinks/day of liquor had lower odds of optimal scores compared to those who never drank liquor [0.32 (0.16–0.65)]. CONCLUSION: Moderate consumption of wine was associated with favorable CVH. However, heavy consumption of beer or liquor was associated with poorer CVH

    Utility of Nontraditional Risk Markers in Atherosclerotic Cardiovascular Disease Risk Assessment

    Get PDF
    AbstractBackgroundThe improvement in discrimination gained by adding nontraditional cardiovascular risk markers cited in the 2013 American College of Cardiology/American Heart Association cholesterol guidelines to the atherosclerotic cardiovascular disease (ASCVD) risk estimator (pooled cohort equation [PCE]) is untested.ObjectivesThis study assessed the predictive accuracy and improvement in reclassification gained by the addition of the coronary artery calcium (CAC) score, the ankle–brachial index (ABI), high-sensitivity C-reactive protein (hsCRP) levels, and family history (FH) of ASCVD to the PCE in participants of MESA (Multi-Ethnic Study of Atherosclerosis).MethodsThe PCE was calibrated (cPCE) and used for this analysis. The Cox proportional hazards survival model, Harrell’s C statistics, and net reclassification improvement analyses were used. ASCVD was defined as myocardial infarction, coronary heart disease–related death, or fatal or nonfatal stroke.ResultsOf 6,814 MESA participants not prescribed statins at baseline, 5,185 had complete data and were included in this analysis. Their mean age was 61 years; 53.1% were women, 9.8% had diabetes, and 13.6% were current smokers. After 10 years of follow-up, 320 (6.2%) ASCVD events occurred. CAC score, ABI, and FH were independent predictors of ASCVD events in the multivariable Cox models. CAC score modestly improved the Harrell’s C statistic (0.74 vs. 0.76; p = 0.04); ABI, hsCRP levels, and FH produced no improvement in Harrell’s C statistic when added to the cPCE.ConclusionsCAC score, ABI, and FH were independent predictors of ASCVD events. CAC score modestly improved the discriminative ability of the cPCE compared with other nontraditional risk markers
    • …
    corecore