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Multi-Ethnic Study (multi-ethnic + study)
Selected AbstractsPredicting intra-urban variation in air pollution concentrations with complex spatio-temporal dependencies,ENVIRONMETRICS, Issue 6 2010Adam A. Szpiro Abstract We describe a methodology for assigning individual estimates of long-term average air pollution concentrations that accounts for a complex spatio-temporal correlation structure and can accommodate spatio-temporally misaligned observations. This methodology has been developed as part of the Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA Air), a prospective cohort study funded by the US EPA to investigate the relationship between chronic exposure to air pollution and cardiovascular disease. Our hierarchical model decomposes the space--time field into a "mean" that includes dependence on covariates and spatially varying seasonal and long-term trends and a "residual" that accounts for spatially correlated deviations from the mean model. The model accommodates complex spatio-temporal patterns by characterizing the temporal trend at each location as a linear combination of empirically derived temporal basis functions, and embedding the spatial fields of coefficients for the basis functions in separate linear regression models with spatially correlated residuals (universal kriging). This approach allows us to implement a scalable single-stage estimation procedure that easily accommodates a significant number of missing observations at some monitoring locations. We apply the model to predict long-term average concentrations of oxides of nitrogen (NOx) from 2005 to 2007 in the Los Angeles area, based on data from 18 EPA Air Quality System regulatory monitors. The cross-validated IR2 is 0.67. The MESA Air study is also collecting additional concentration data as part of a supplementary monitoring campaign. We describe the sampling plan and demonstrate in a simulation study that the additional data will contribute to improved predictions of long-term average concentrations. Copyright © 2009 John Wiley & Sons, Ltd. [source] Race/ethnicity and telomere length in the Multi-Ethnic Study of AtherosclerosisAGING CELL, Issue 3 2009Ana V. Diez Roux Summary Telomere length has emerged as a marker of exposure to oxidative stress and aging. Race/ethnic differences in telomere length have been infrequently investigated. Leukocyte telomere length (LTL) was assessed 981 white, black and Hispanic men and women aged 45,84 years participating in the Multi-Ethnic Study of Atherosclerosis. Direct measurement and questionnaire were used to assess covariates. Linear regression was used to estimate associations of LTL with race/ethnicity and age after adjustment for sex, income, education, smoking, physical activity, diet and body mass index. On average blacks and Hispanics had shorter telomeres than whites [adjusted mean differences (standard error) in T/S ratio compared to whites: ,0.041 (0.018) for blacks and ,0.044 (0.018) for Hispanics]. Blacks and Hispanics showed greater differences in telomere length associated with age than whites (adjusted mean differences in T/S ratio per 1 year increase in age ,0.0018, ,0.0047 and ,0.0055 in whites, blacks and Hispanics respectively). Differences in age associations were more pronounced and only statistically significant in women. Race/ethnic differences in LTL may reflect the cumulative burden of differential exposure to oxidative stress (and its predictors) over the lifecourse. [source] Estimating ethnic differences in self-reported new use of antidepressant medications: results from the Multi-Ethnic Study of AtherosclerosisPHARMACOEPIDEMIOLOGY AND DRUG SAFETY, Issue 7 2009Joseph A. C. Delaney PhD Abstract Introduction There is evidence that the utilization of antidepressant medications (ADM) may vary between different ethnic groups in the United States population. Methods The Multi-Ethnic Study of Atherosclerosis (MESA) is a population-based prospective cohort study of 6814 US adults from 4 different ethnic groups. After excluding baseline users of ADM, we examined the relation between baseline depression and new use of ADM for 4 different ethnicities: African,Americans (n,=,1822), Asians (n,=,784) Caucasians (n,=,2300), and Hispanics (n,=,1405). Estimates of the association of ethnicity and ADM use were adjusted for age, study site, gender, Center for Epidemiologic Studies Depression Scale (CES-D), alcohol use, smoking, blood pressure, diabetes, education, and exercise. Non-random loss to follow-up was present and estimates were adjusted using inverse probability of censoring weighting (IPCW). Results Of the four ethnicities, Caucasian participants had the highest rate of ADM use (12%) compared with African,American (4%), Asian (2%), and Hispanic (6%) participants. After adjustment, non-Caucasian ethnicity was associated with reduced ADM use: African,American (HR: 0.42; 95% Confidence Interval (CI): 0.31,0.58), Asian (HR: 0.14; 95%CI: 0.08,0.26), and Hispanic (HR: 0.47; 95%CI: 0.31,0.65). Applying IPCW to correct for non-random loss to follow-up among the study participants weakened but did not eliminate these associations: African,American (HR: 0.48; 95%CI: 0.30,0.57), Asian (HR: 0.23; 95%CI: 0.13,0.37), and Hispanic (HR: 0.58; 95%CI: 0.47,0.67). Conclusion Non-Caucasian ethnicity is associated with lower rates of new ADM use. After IPCW adjustment, the observed ethnicity differences in ADM use are smaller although still statistically significant. Copyright © 2009 John Wiley & Sons, Ltd. [source] Left ventricular structure and function in patients with rheumatoid arthritis, as assessed by cardiac magnetic resonance imagingARTHRITIS & RHEUMATISM, Issue 4 2010Jon T. Giles Objective Heart failure is a major contributor to cardiovascular morbidity and mortality in patients with rheumatoid arthritis (RA), but little is known about myocardial structure and function in this population. This study was undertaken to assess the factors associated with progression to heart failure in patients with RA. Methods With the use of cardiac magnetic resonance imaging, measures of myocardial structure and function were assessed in men and women with RA enrolled in the Evaluation of Subclinical Cardiovascular Disease and Predictors of Events in Rheumatoid Arthritis study, a cohort study of subclinical cardiovascular disease in patients with RA, in comparison with non-RA control subjects from a cohort enrolled in the Baltimore Multi-Ethnic Study of Atherosclerosis. Results Measures of myocardial structure and function were compared between 75 patients with RA and 225 frequency-matched controls. After adjustment for confounders, the mean left ventricular mass was found to be 26 gm lower in patients with RA compared with controls (P < 0.001), an 18% difference. In addition, the mean left ventricular ejection fraction, cardiac output, and stroke volume were modestly lower in the RA group compared with controls. The mean left ventricular end systolic and end diastolic volumes did not differ between the groups. In patients with RA, higher levels of anti,cyclic citrullinated peptide (anti-CCP) antibodies and current use of biologic agents, but not other measures of disease activity or severity, were associated with significantly lower adjusted mean values for the left ventricular mass, end diastolic volume, and stroke volume, but not with ejection fraction. The combined associations of anti-CCP antibody level and biologic agent use with myocardial measures were additive, without evidence of interaction. Conclusion These findings suggest that the progression to heart failure in RA may occur through reduced myocardial mass rather than hypertrophy. Both modifiable and nonmodifiable factors may contribute to lower levels of left ventricular mass and volume. [source] Plasma hemostatic factors and endothelial markers in four racial/ethnic groups: the MESA studyJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 12 2006P. L. LUTSEY Summary.,Background:,Hemostatic factors and endothelial markers may play some role in racial/ethnic differences in cardiovascular disease (CVD) rates. However, little information exists on hemostatic factors and endothelial markers across racial/ethnic groups. Objectives:,To describe, in four American racial/ethnic groups (Caucasian, Black, Hispanic, and Chinese), mean levels of selected hemostatic factors and endothelial markers. Patients and methods:,Multi-ethnic Study of Atherosclerosis baseline data were used (participant age: 45,84 years). Sex-specific analysis of covariance models, and t -tests for pairwise comparisons, were used to compare means of factors and markers. Adjustments were made for demographics and traditional CVD risk factors. Differences were significant at P < 0.05. Results:,Blacks had the highest levels of factor VIII, D-Dimer, plasmin,antiplasmin (PAP), and von Willebrand factor, among the highest levels of fibrinogen and E-selectin (women only), but among the lowest levels of intercellular adhesion molecule 1 (ICAM-1), and, in men, the lowest levels of plasminogen activator inhibitor-1 (PAI-1). Whites and Hispanics tended to have intermediate levels of factors and markers, although they had the highest levels of ICAM-1, and Hispanics had the highest mean levels of fibrinogen and E-selectin (women only). Chinese participants had among the highest levels of PAI-1, but the lowest, or among the lowest, of all other factors and markers. No soluble thrombomodulin differences were observed. Conclusions:,In this large cohort, hemostatic factor and endothelial marker mean levels varied by race/ethnicity, even after adjustment for traditional CVD risk factors. [source] | ||||||||||