[Show abstract][Hide abstract] ABSTRACT: To investigate associations of work hours, job control, job demands, job strain, and occupational category with endothelial function, a predictor of cardiovascular disease (CVD).
Occupational and Environmental Medicine 06/2014; 71 Suppl 1:A73. · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Abstract Introduction: The contribution of occupational exposure to the risk of chronic obstructive pulmonary disease COPD in population-based studies is of interest. We compared the performance of self-reported exposure to a newly developed JEM in exposure-response evaluation. Methods: We used cross-sectional data from Multi-Ethnic Study of Atherosclerosis (MESA), a population-based sample of 45-84 year olds free of clinical cardiovascular disease at baseline. MESA ascertained the most recent job and employment, and the MESA Lung Study measured spirometry, and occupational exposures for 3686 participants. Associations between health outcomes (spirometry defined airflow limitation and Medical Research Council-defined chronic bronchitis) and occupational exposure [self-reported occupational exposure to vapor-gas, dust, or fumes (VGDF), severity of exposure, and a job-exposure matrix (JEM)-derived score] were evaluated using logistic regression models adjusted for non-occupational risk factors. Results: The prevalence of airflow limitation was associated with self-reported exposure to vapor-gas (OR 2.6, 95%CI 1.1-2.3), severity of VGDF exposure (P-trend < 0.01), and JEM dust exposure (OR 2.4, 95%CI 1.1-5.0), and with organic dust exposure in females; these associations were generally of greater magnitude among never smokers. The prevalence of chronic bronchitis and wheeze was associated with exposure to VGDF. The association between airflow limitation and the combined effect of smoking and VGDF exposure showed an increasing trend. Self-reported vapor-gas, dust, fumes, years and severity of exposure were associated with increased prevalence of chronic bronchitis and wheeze (P < 0.001). Conclusions: Airflow limitation was associated with self-reported VGDF exposure, its severity, and JEM-ascertained dust exposure in smokers and never-smokers in this multiethnic study.
[Show abstract][Hide abstract] ABSTRACT: Rationale: Pulmonary emphysema overlaps partially with spirometrically defined chronic obstructive pulmonary disease and is heritable, with moderately high familial clustering. Objectives: To complete a genome-wide association study (GWAS) for the percentage of emphysema-like lung on CT in the MESA Lung/SHARe Study, a large, population-based cohort in the United States. Methods: We determined percent emphysema and upper-lower lobe ratio in emphysema defined by lung regions less than -950 HU on cardiac scans. Genetic analyses were reported combined across four race/ethnic groups: non-Hispanic White (n=2,587), African American (n=2,510), Hispanic (n=2,113) and Chinese (n=704) and stratified by race/ethnicity. Measurements and Main Results: Among 7,914 participants, we identified regions at genome-wide significance for percent emphysema in or near SNRPF (rs7957346, P=2.2E-8) and PPT2 (rs10947233, P=3.2E-8), both of which replicated in an additional 6,023 individuals of European ancestry. Both SNPs were previously implicated as genes influencing lung function, and analyses including lung function revealed independent associations for percent emphysema. Among Hispanics, we identified a genetic locus for upper-lower lobe ratio near the alpha-mannosidase-related gene MAN2B1 (rs10411619, P=1.1E-9, minor allele frequency [MAF]=4.4%). Among Chinese, we identified SNPs associated with upper-lower lobe ratio near DHX15 (rs7698250, P=1.8E-10, MAF=2.7%) and MGAT5B (rs7221059, P=2.7E-8, MAF=2.6%), which acts on alpha-linked mannose. Among African-Americans, a locus near a third alpha-mannnosidase-related gene, MAN1C1 (rs12130495, P=9.9E-6, MAF=13.3%) was associated with percent emphysema. Conclusions: Our results suggest some genes previously identified as influencing lung function genes are independently associated with emphysema, and that genes related to alpha-mannosidase may influence risk of pulmonary emphysema.
American Journal of Respiratory and Critical Care Medicine 01/2014; · 11.04 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Long working hours may be associated with cardiovascular disease (CVD). The objective was to investigate cross-sectional associations of work hours with carotid intima-media thickness (CIMT) and ankle-brachial index (ABI).
Participants were 1694 women and 1868 men from the Multi-Ethnic Study of Atherosclerosis. CIMT and ABI were measured using standard protocols. Information on work hours was obtained from questionnaires. Mean values of CIMT and ABI were examined across five categories of hours worked per week (≤20, 21-39, 40, 41-50 and >50) using analysis of variance/analysis of covariance. p Values for trend were obtained from linear regression models.
Mean age of participants was 56.9±8.4 years; 52.4% were men. Distinct patterns of association between work hours and the subclinical CVD biomarkers were found for women and men, although this heterogeneity by gender was not statistically significant. Among women only, work hours were positively associated with common (but not internal) CIMT (p=0.073) after full risk factor adjustment. Compared with women working 40 h, those working >50 h were more likely to have an ABI <1 (vs 1-1.4) (OR=1.85, 95% CI 1.01 to 3.38). In men, work hours and ABI were inversely associated (p=0.046). There was some evidence that the association between work hours and ABI was modified by occupational category (interaction p=0.061). Among persons classified as management/professionals, longer work hours was associated with lower ABI (p=0.015). No significant associations were observed among other occupational groups.
Working longer hours may be associated with subclinical CVD. These associations should be investigated using longitudinal studies.
Occupational and environmental medicine 07/2012; 69(10):713-20. · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: This study examines associations of occupation with smoking status, amount smoked among current and former smokers (number of cigarettes per day and lifetime cigarette consumption (pack-years)), and workplace exposure to environmental tobacco smoke (ETS) independent from income and education.
This is a cross-sectional analysis of data from a community sample (n = 6355, age range: 45-84) using logistic and multinomial regression. All analyses were stratified by sex and adjusted for socio-demographic variables.
Male blue-collar and sales/office workers had higher odds of having consumed more than 20 pack-years of cigarettes than managers/professionals. For both male and female current or former smokers, exposure to workplace ETS was consistently and strongly associated with heavy smoking and greater pack-years.
Blue-collar workplaces are associated with intense smoking and ETS exposure. Smoking must be addressed at both the individual and workplace levels especially in blue-collar workplaces.
Journal of occupational and environmental medicine / American College of Occupational and Environmental Medicine 02/2012; 54(2):136-45. · 1.88 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Immigrants have a different social context from those who stay in their home country or those who were born to the country that immigrants now live. Cultural theory of risk perception suggests that social context influences one's interpretation of questionnaire items. We examined psychometric properties of job control and job demand scales with US- and foreign-born workers who preferred English, Spanish, or Chinese (n = 3,114, mean age = 58.1). Across all groups, the job control scale had acceptable Cronbach's alpha (0.78-0.83) and equivalent factor loadings (ΔCFI < 0.01). Immigrants had low alpha (0.42-0.65) for the job demands scale regardless of language, education, or age of migration. Two job-demand items had different factor loadings across groups. Among immigrants, both scales had inconsistent associations with perceived job stress and self-rated health. For a better understanding of immigrants' job stress, the concept of job demands should be expanded and immigrants' expectations for job control explored.
Journal of Immigrant and Minority Health 06/2011; 13(3):533-40. · 1.16 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Occupation has been linked to cardiovascular disease (CVD) incidence and mortality, but few studies have investigated occupation in relation to early atherosclerotic disease. This study examined associations between various occupational characteristics and carotid artery intima-media thickness (IMT) in a multi-ethnic sample.
The Multi-Ethnic Study of Atherosclerosis (MESA) recruited 6814 adults aged 45-84 years and free of clinical CVD (response rate 60%, 51% female). Questionnaire data were used to determine occupational group (managerial/professional, sales/office, service, blue-collar), psychosocial job characteristics (ie, job demands, job control) and other sociodemographic information.
Common carotid artery (CCA)-IMT was greater for blue-collar jobs than for management/professional jobs (mean difference = 0.012 mm, p = 0.049) after adjustment for age, sex, race, place of birth (US or foreign born) and CVD risk factors. Compared to management/professional jobs, internal carotid artery (ICA)-IMT was greater for sales/office, service and blue-collar jobs (mean difference = 0.071 mm, p < 0.001; 0.057 mm, p = 0.009; and 0.110 mm, p < 0.001, respectively) after adjustment for age, sex, race and place of birth. The difference between blue-collar jobs and management/professional jobs remained significant after additional adjustment for CVD risk factors, income and education (mean difference = 0.048 mm, p = 0.045). Higher levels of control at work were associated with thinner CCA-IMT (mean difference = -0.009 mm, p = 0.016, adjusted for age, sex, race and place of birth) but not with ICA-IMT. Job demands had no significant association with IMT.
Blue-collar jobs and low levels of job control were associated with the development of subclinical atherosclerosis.
Occupational and environmental medicine 10/2010; 68(5):319-26. · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The American Thoracic Society recommends race-specific spirometric reference values from the National Health and Nutrition Survey (NHANES) III for clinical evaluation of pulmonary function in whites, African-Americans, and Mexican-Americans in the United States and a correction factor of 0.94 for Asian-Americans. We aimed to validate the NHANES III reference equations and the correction factor for Asian-Americans in an independent, multiethnic sample of US adults.
The Multi-Ethnic Study of Atherosclerosis (MESA) recruited self-identified non-Hispanic white, African-American, Hispanic, and Asian-American participants aged 45 to 84 years at six US sites. The MESA-Lung Study assessed prebronchodilator spirometry among 3,893 MESA participants who performed acceptable tests, of whom 1,068 were asymptomatic healthy nonsmokers who performed acceptable spirometry.
The 1,068 participants were mean age 65 +/- 10 years, 60% female, 25% white, 20% African-American, 23% Hispanic, and 32% Asian-American. Observed values of FEV(1), FEV(6), and FVC among whites, African-Americans, and Hispanics of Mexican origin in MESA-Lung were slightly lower than predicted values based on NHANES III. Observed values among Hispanics of non-Mexican origin were consistently lower. Agreement in classification of participants with airflow obstruction based on lower limit of normal criteria was good (overall kappa = 0.88). For Asian-Americans, a correction factor of 0.88 was more accurate than 0.94.
The NHANES III reference equations are valid for use among older adults who are white, African-American, or Hispanic of Mexican origin. Comparison of white and Asian-American participants suggests that a correction factor of 0.88, applied to the predicted and lower limits of normal values, is more appropriate than the currently recommended value of 0.94.
[Show abstract][Hide abstract] ABSTRACT: Maximum inspiratory pressure (MIP) is an important and noninvasive index of diaphragm strength and an independent predictor of all-cause mortality. The ability of adults over a wide age range and multiple race/ethnicities to perform MIP tests has previously not been evaluated.
The Multi-Ethnic Study of Atherosclerosis recruited white, African American, Hispanic, and Chinese American participants, ages 45-84 years, and free of clinical cardiovascular disease in 6 United States cities. MIP was measured using standard techniques among 3,849 Multi-Ethnic Study of Atherosclerosis participants. The MIP quality goal was 5 maneuvers, with the 2 largest values matching within 10 cm H2O. Correlates of MIP quality and values were assessed in logistic and linear regression models.
The 3,849 participants with MIP measures were 51% female, 35% white, 26% African American, 23% Hispanic, and 16% Chinese American. Mean+/-SD MIP was 73+/-26 cm H2O for women and 97+/-29 cm H2O for men. The quality goal was achieved by 83% of the cohort and was associated with female sex, older age, race/ethnicity, study site, low ratio of forced expiratory volume in the first second to forced vital capacity (FEV1/FVC), and wheeze with dyspnea. The multivariate correlates of MIP were male sex, younger age, higher body mass index, shorter height, higher FVC, higher systolic blood pressure (in women) and health status (in men). There were no clinically important race/ethnic differences in MIP values.
Race-specific reference equations for MIP are unnecessary in the United States. More than 80% of adults can be successfully coached for 5 maneuvers, with repeatability within 10 cm H2O.
Respiratory care 10/2009; 54(10):1321-8. · 1.84 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Most published epidemiology studies of long-term air pollution health effects have relied on central site monitoring to investigate regional-scale differences in exposure. Few cohort studies have had sufficient data to characterize localized variations in pollution, despite the fact that large gradients can exist over small spatial scales. Similarly, previous data have generally been limited to measurements of particle mass or several of the criteria gases. The Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA Air) is an innovative investigation undertaken to link subclinical and clinical cardiovascular health effects with individual-level estimates of personal exposure to ambient-origin pollution. This project improves on prior work by implementing an extensive exposure assessment program to characterize long-term average concentrations of ambient-generated PM2.5, specific PM2.5 chemical components, and copollutants, with particular emphasis on capturing concentration gradients within cities. This paper describes exposure assessment in MESA Air, including questionnaires, community sampling, home monitoring, and personal sampling. Summary statistics describing the performance of the sampling methods are presented along with descriptive statistics of the air pollution concentrations by city.
Environmental Science and Technology 08/2009; 43(13):4687-93. · 5.48 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Cardiac computed tomographic (CT) scans for the assessment of coronary calcium scores include approximately 70% of the lung volume and may be useful for the quantitative assessment of emphysema. The reproducibility of lung density measures from cardiac computed tomography and their validity compared to lung density measures from full-lung scans is unknown.
The Multi-Ethnic Study of Atherosclerosis (MESA) performed paired cardiac CT scans for 6814 participants at baseline and at follow-up. The MESA-Lung Study assessed lung density measures in the lung fields of these cardiac scans, counting voxels below -910 HU as moderate-to-severe emphysema-like lung regions. We evaluated: 1) the reproducibility of lung density measures among 120 randomly selected participants; 2) the comparability of measures acquired on electron beam CT (EBCT) and multidetector CT (MDCT) scanners among 10 participants; and 3) the validity of these measures compared to full-lung scans among 42 participants. Limits of agreement were determined using Bland-Altman approaches.
Percent emphysema measures from paired cardiac scans were highly correlated (r = 0.92-0.95) with mean difference of -0.05% (95% limits of agreement: -8.3, 8.4%). Measures from EBCT and MDCT scanners were comparable (mean difference -0.9%; 95% limits of agreement: -5.1, 3.3%). Percent emphysema measures from MDCT cardiac and MDCT full-lung scans were highly correlated (r = 0.93) and demonstrated reasonable agreement (mean difference 2.2%; 95% limits of agreement: -9.2, 13.8%).
Although full-lung imaging is preferred for the quantification of emphysema, the lung imaging from paired cardiac computed tomography provided a reproducible and valid quantitative assessment of emphysema in a population-based sample.
[Show abstract][Hide abstract] ABSTRACT: The initiation and acceleration of atherosclerosis is hypothesized as a physiologic mechanism underlying associations between air pollution and cardiovascular effects. Despite toxicologic evidence, epidemiologic data are limited.
In this cross-sectional analysis we investigated exposure to fine particulate matter (PM2.5) and residential proximity to major roads in relation to abdominal aortic calcification, a sensitive indicator of systemic atherosclerosis. Aortic calcification was measured by computed tomography among 1147 persons, in 5 US metropolitan areas, enrolled in the Multi-Ethnic Study of Atherosclerosis. The presence and quantity of aortic calcification were modeled using relative risk regression and linear regression, respectively, with adjustment for potential confounders.
We observed a slightly elevated risk of aortic calcification (RR = 1.06; 95% confidence interval = 0.96-1.16) with a 10 microg/m contrast in PM2.5. The PM2.5-associated risk of aortic calcification was stronger among participants with long-term residence near a PM2.5 monitor (RR = 1.11; 1.00-1.24) and among participants not recently employed outside the home (RR = 1.10; 1.00-1.22). PM2.5 was not associated with an increase in the quantity of aortic calcification (Agatston score) and no roadway proximity effects were noted. There was indication of PM2.5 effect modification by lipid-lowering medication use, with greater effects among users, and PM2.5 associations were observed most consistently among Hispanics.
Although we did not find persuasive associations across our full study population, associations were stronger among participants with less exposure misclassification. These findings support the hypothesis of a relationship between particulate air pollution and systemic atherosclerosis.