Browsing by Author "Hickson, DeMarc A."

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    Associations between air pollution indicators and prevalent and incident diabetes in an African American cohort, the Jackson Heart Study
    (Wolters Kluwer, 2021-04-22) Weaver, Anne M.; Bidulescu, Aurelian; Wellenius, Gregory A.; Hickson, DeMarc A.; Sims, Mario; Vaidyanathan, Ambarish; Wu, Wen-Chih; Correa, Adolfo; Wang, Yi; Environmental Health Science, School of Public Health
    Background: Diabetes is especially prevalent among African Americans. Prior studies suggest that long-term exposure to ambient air pollution may be associated with greater incidence of diabetes, but results remain heterogeneous. Few studies have included large numbers of African Americans. Methods: We assessed diabetes status and concentrations of 1- and 3-year fine particulate matter (PM2.5) and ozone (O3) among African American participants of the Jackson Heart Study at visits 1 (2000-2004, N = 5128) and 2 (2005-2008, N = 2839). We used mixed-effect modified Poisson regression to estimate risk ratios (RRs) and 95% confidence intervals (CIs) of incidence of diabetes by visit 2 and prevalence ratios (PRs) of the association between air pollution exposure and prevalent diabetes at visits 1 and 2. We adjusted for potential confounding by patient characteristics, as well as inverse probability weights of diabetes at visit 2, accounting for clustering by census tract. Results: We observed associations between incident diabetes and interquartile range increase in 1-year O3 (RR 1.34, 95% CI = 1.11, 1.61) and 3-year O3 (RR 0.88, 95% CI = 0.76, 1.02). We observed associations between prevalent diabetes and 1-year PM2.5 (PR 1.08, 95% CI = 1.00, 1.17), 1-year O3 (PR 1.18, 95% CI = 1.10, 1.27), and 3-year O3 (PR 0.95, 95% CI = 0.90, 1.01) at visit 2. Conclusions: Our results provide some evidence of positive associations between indicators of long-term PM2.5 and O3 exposure and diabetes. This study is particularly relevant to African Americans, who have higher prevalence of diabetes but relatively few studies of environmental pollution risk factors.
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    Long-term air pollution and blood pressure in an African-American cohort: the Jackson Heart Study
    (Elsevier, 2021) Weaver, Anne M.; Wang, Yi; Wellenius, Gregory A.; Bidulescu, Aurelian; Sims, Mario; Vaidyanathan, Ambarish; Hickson, DeMarc A.; Shimbo, Daichi; Abdalla, Marwah; Diaz, Keith M.; Seals, Samantha R.; Epidemiology, Richard M. Fairbanks School of Public Health
    Introduction: African Americans are disproportionately affected by high blood pressure, which may be associated with exposure to air pollutants, such as fine particulate matter and ozone. Methods: Among African American Jackson Heart Study participants, this study examined associations between 1-year and 3-year mean fine particulate matter and ozone concentrations with prevalent and incident hypertension at Visits 1 (2000-2004, n=5,191) and 2 (2005-2008, n=4,105) using log binomial regression. Investigators examined associations with systolic blood pressure, diastolic blood pressure, pulse pressure, and mean arterial pressure using linear regression and hierarchical linear models, adjusting for sociodemographic, behavioral, and clinical characteristics. Analyses were conducted in 2017-2019. Results: No associations were observed between fine particulate matter or ozone concentration and prevalent or incident hypertension. In linear models, an IQR increase in 1-year ozone concentration was associated with 0.67 mmHg higher systolic blood pressure (95% CI=0.27, 1.06), 0.42 mmHg higher diastolic blood pressure (95% CI=0.20, 0.63), and 0.50 mmHg higher mean arterial pressure (95% CI=0.26, 0.74). In hierarchical models, fine particulate matter was inversely associated with systolic blood pressure (-0.72, 95% CI= -1.31, -0.13), diastolic blood pressure (-0.69, 95% CI= -1.02, -0.36), and mean arterial pressure (-0.71, 95% CI= -1.08, -0.33). Attenuated associations were observed with 1-year concentrations and at Visit 1. Conclusions: Positive associations were observed between ozone and systolic blood pressure, diastolic blood pressure, and mean arterial pressure, and inverse associations between fine particulate matter and systolic blood pressure, diastolic blood pressure, and mean arterial pressure in an African American population with high (56%) prevalence of hypertension. Effect sizes were small and may not be clinically relevant.
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    Long-term exposure to ambient air pollution and renal function in African Americans: the Jackson Heart Study
    (Springer Nature, 2019-06) Weaver, Anne M.; Wang, Yi; Wellenius, Gregory A.; Young, Bessie; Boyle, Luke D.; Hickson, DeMarc A.; Diamantidis, Clarissa J.; Environmental Health Science, School of Public Health
    Renal dysfunction is prevalent in the US among African Americans. Air pollution is associated with renal dysfunction in mostly white American populations, but has not been studied among African Americans. We evaluated cross-sectional associations between 1-year and 3-year fine particulate matter (PM2.5) and ozone (O3) concentrations, and renal function among 5090 African American participants in the Jackson Heart Study. We used mixed-effect linear regression to estimate associations between 1-year and 3-year PM2.5 and O3 and estimated glomerular filtration rate (eGFR), urine albumin/creatinine ratio (UACR), serum creatinine, and serum cystatin C, adjusting for: sociodemographic factors, health behaviors, and medical history and accounting for clustering by census tract. At baseline, JHS participants had mean age 55.4 years, and 63.8% were female; mean 1-year and 3-year PM2.5 concentrations were 12.2 and 12.4 µg/m3, and mean 1-year and 3-year O3 concentrations were 40.2 and 40.7 ppb, respectively. Approximately 6.5% of participants had reduced eGFR (< 60 mL/min/1.73m2) and 12.7% had elevated UACR (> 30 mg/g), both indicating impaired renal function. Annual and 3-year O3 concentrations were inversely associated with eGFR and positively associated with serum creatinine; annual and 3-year PM2.5 concentrations were inversely associated with UACR. We observed impaired renal function associated with increased O3 but not PM2.5 exposure among African Americans.
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    Residential distance to major roadways and cardiac structure in African Americans: cross-sectional results from the Jackson Heart Study
    (BioMed Central, 2017) Weaver, Anne M.; Wellenius, Gregory A.; Wu, Wen-Chih; Hickson, DeMarc A.; Kamalesh, Masoor; Wang, Yi; Department of Environmental Health Sciences, Richard M. Fairbanks School of Public Health
    Heart failure (HF) is a significant source of morbidity and mortality among African Americans. Ambient air pollution, including from traffic, is associated with HF, but the mechanisms remain unknown. The objectives of this study were to estimate the cross-sectional associations between residential distance to major roadways with markers of cardiac structure: left ventricular (LV) mass index, LV end-diastolic diameter, LV end-systolic diameter, and LV hypertrophy among African Americans.
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    Residential Proximity to Major Roadways Is Not Associated with Cardiac Function in African Americans: Results from the Jackson Heart Study
    (MDPI, 2016-06-13) Weaver, Anne M.; Wellenius, Gregory A.; Wu, Wen-Chih; Hickson, DeMarc A.; Kamalesh, Masoor; Wang, Yi; Department of Environmental Health Sciences, FSPH
    Cardiovascular disease (CVD), including heart failure, is a major cause of morbidity and mortality, particularly among African Americans. Exposure to ambient air pollution, such as that produced by vehicular traffic, is believed to be associated with heart failure, possibly by impairing cardiac function. We evaluated the cross-sectional association between residential proximity to major roads, a marker of long-term exposure to traffic-related pollution, and echocardiographic indicators of left and pulmonary vascular function in African Americans enrolled in the Jackson Heart Study (JHS): left ventricular ejection fraction, E-wave velocity, isovolumic relaxation time, left atrial diameter index, and pulmonary artery systolic pressure. We examined these associations using multivariable linear or logistic regression, adjusting for potential confounders. Of 4866 participants at study enrollment, 106 lived <150 m, 159 lived 150–299 m, 1161 lived 300–999 m, and 3440 lived ≥1000 m from a major roadway. We did not observe any associations between residential distance to major roads and these markers of cardiac function. Results were similar with additional adjustment for diabetes and hypertension, when considering varying definitions of major roadways, or when limiting analyses to those free from cardiovascular disease at baseline. Overall, we observed little evidence that residential proximity to major roads was associated with cardiac function among African Americans.
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    Residential Proximity to Traffic-Related Pollution and Atherosclerosis in 4 Vascular Beds Among African-American Adults: Results From the Jackson Heart Study
    (Oxford Academic, 2016-11-15) Wang, Yi; Wellenius, Gregory A.; Hickson, DeMarc A.; Gjelsvik, Annie; Eaton, Charles B.; Wyatt, Sharon B.; Environmental Health Science, School of Public Health
    To our knowledge, no study has investigated the association of long-term exposure to traffic pollution with markers of atherosclerosis in 4 vascular beds simultaneously in an all-African-American cohort. Among participants in the Jackson Heart Study (Jackson, Mississippi; baseline mean age = 55.5 (standard deviation, 12.7) years), we used linear regression to estimate percent differences in carotid intima-media thickness (CIMT) at baseline (2004) and used modified Poisson regression (robust error variance) to estimate prevalence ratios for peripheral artery disease (PAD), coronary artery calcification (CAC), and abdominal aortic calcification (AAC) at the first follow-up visit (2005–2008) for persons living less than 150 m (versus more than 300 m) from major roadways, adjusting for confounders. Living less than 150 m from such roadways was associated with a significant 6.67% (95% confidence interval: 1.28, 12.35) increase in CIMT (4,800 participants). PAD prevalence among persons living less than 150 m from a major roadway was 1.17 (95% confidence interval: 0.73, 1.86) times that of persons living more than 300 m away (4,443 participants), but this result was not statistically significant. There was no association for CAC or AAC. The association with CIMT was stronger in participants with a cardiovascular disease history than in those without one (P = 0.04). We observed an association in the carotid vascular beds but not the coronary, abdominal, or peripheral vascular beds. Our results highlight the need to consider residential proximity to roadways as a potential cardiovascular disease risk factor for blacks.