Shawnita Sealy-Jefferson

Arsenic in Drinking Water and Stroke Hospitalizations in Michigan

Background and Purpose— Mechanistic and human studies suggest a role for arsenic in ischemic stroke; however, risks from chronic, low-level exposures are uncertain and US studies are lacking. The objective was to investigate the association between low-level arsenic exposure in drinking water and ischemic stroke hospital admissions in Michigan. Methods— Ischemic stroke hospital admissions among those aged ≥45 years were identified (1994 to 2006). Population-weighted average arsenic concentrations were estimated for each Michigan county (n=83) and for zip codes in Genesee County (n=27) where there is greater variation in arsenic concentrations. US Census data provided age- and sex-specific population counts and other county- and zip code-level variables (race, income), which were adjusted for in multilevel negative binomial regression models of arsenic and stroke admissions. Hospital admissions for duodenal ulcer and hernia, not hypothesized to be associated with arsenic, were also evaluated. Results— Adjusted county-level analyses suggested a relationship between arsenic and ischemic stroke hospital admissions, although similar associations were observed for duodenal ulcer and hernia. In zip code-level analysis, arsenic was associated with an increased risk of stroke admission (relative risk, 1.03; 95% CI, 1.01 to 1.05 per &mgr;g/L increase in arsenic) after adjustment for confounders, and null or negative associations were found between arsenic and nonvascular outcomes. Conclusions— Findings from this study suggest that exposure to even low levels of arsenic in drinking water may be associated with a higher risk of incident stroke. Given the ecological nature of the analysis, further epidemiological study with individual-level data on arsenic exposure and incident stroke is warranted.

Age- and ethnic-specific sex differences in stroke risk.

BACKGROUND In white populations, age seems to modify the effect of sex on stroke risk, and compared with men, women are protected from stroke until approximately age 75 to 85 years, after which the protection is lost or reversed. Compared with non-Hispanic whites (NHWs), Mexican Americans (MAs) are at higher risk of stroke; however, age- and sex-specific stroke incidence data are currently not available for this population. OBJECTIVE This study was performed to compare the age-specific sex differences in stroke risk in MAs and NHWs. METHODS Data were derived from the BASIC (Brain Attack Surveillance in Corpus Christi) Project, a population-based stroke surveillance study conducted in Nueces County Texas. Incident strokes (n = 2421, including ischemic stroke, intracerebral hemorrhage, and subarachnoid hemorrhage) that occurred between January 1, 2000 and May 25, 2007 in individuals aged 45 years or older were included in the analysis. Poisson regression using the generalized additive models framework was used to analyze the relationship between sex, age (5-year intervals), and race/ethnicity (NHW or MA) and incident stroke risk. RESULTS Among both NHWs and MAs aged 45 to 79 years, men were at higher risk of stroke than women were. The magnitude of increased stroke risk in men compared with women diminished with age, and after age 79 years, no sex difference in stroke risk was observed. CONCLUSIONS Reasons for the loss of protection from stroke in aging women of all races/ethnicities are not fully understood, and further study is warranted.

The impact of neighborhood quality, perceived stress, and social support on depressive symptoms during pregnancy in African American women

Living in a lower-quality neighborhood is associated with higher levels of depressive symptoms in the general population as well as among pregnant and postpartum women. However, little is known of the important pathways by which this association occurs. We proposed a model in which perceived stress and social support mediated the effects of neighborhood quality on depressive symptoms during pregnancy (measured by the 20-item Center for Epidemiologic Studies-Depression, CES-D, scale) in a sample of 1383 African American women from the Detroit metropolitan area interviewed during their delivery hospitalization. Using structural equation modeling (SEM), we built a latent variable of neighborhood quality using 4 measures (neighborhood disorder, neighborhood safety/danger, walking environment, overall rating). We then tested two SEM mediation models. We found that lower neighborhood quality was associated with higher prevalence of depressive symptoms during pregnancy (standardized total effect = .16, p = .011). We found that perceived stress partially mediated the neighborhood quality association with depressive symptoms. Although the association of social support with depressive symptoms was negligible, social support mediated associations of neighborhood quality with perceived stress [standardized path coefficient = .38 (.02), p = .009]. Our results point to the need for public health, health care, as well as non-health related interventions (e.g. crime prevention programs) to decrease overall exposure to stressors, as well as stress levels of women living in poor quality neighborhoods. Interventions that increase the levels of social support of women during pregnancy are also needed for their potential to decrease stress and ultimately improve mental health at this important time in the life course.

Birth weight and subsequent risk of cancer

BACKGROUND We aimed to determine the association between self-reported birth weight and incident cancer in the Womens Health Initiative Observational Study cohort, a large multiethnic cohort of postmenopausal women. METHODS 65,850 women reported their birth weight by category (<6 lbs, 6-7 lbs 15 oz, 8-9 lbs 15 oz, and ≥10 lbs). All self-reported, incident cancers were adjudicated by study staff. We used Cox proportional hazards regression to estimate crude and adjusted hazard ratios (aHR) for associations between birth weight and: (1) all cancer sites combined, (2) gynecologic cancers, and (3) several site-specific cancer sites. RESULTS After adjustments, birth weight was positively associated with the risk of lung cancer (p=0.01), and colon cancer (p=0.04). An inverse trend was observed between birth weight and risk for leukemia (p=0.04). A significant trend was not observed with breast cancer risk (p=0.67); however, women born weighing ≥10 lbs were less likely to develop breast cancer compared to women born between 6 lbs-7 lbs 15 oz (aHR 0.77, 95% CI 0.63, 0.94). CONCLUSION Birth weight category appears to be significantly associated with the risk of any postmenopausal incident cancer, though the direction of the association varies by cancer type.

Racism in the form of micro aggressions and the risk of preterm birth among black women

PURPOSE This study sought to examine whether perceived interpersonal racism in the form of racial micro aggressions was associated with preterm birth (PTB) and whether the presence of depressive symptoms and perceived stress modified the association. METHODS Data stem from a cohort of 1410 black women residing in Metropolitan Detroit, Michigan, enrolled into the Life-course Influences on Fetal Environments (LIFE) study. The Daily Life Experiences of Racism and Bother (DLE-B) scale measured the frequency and perceived stressfulness of racial micro aggressions experienced during the past year. Severe past-week depressive symptomatology was measured by the Centers for Epidemiologic Studies-Depression scale (CES-D) dichotomized at ≥ 23. Restricted cubic splines were used to model nonlinearity between perceived racism and PTB. We used the Perceived Stress Scale to assess general stress perceptions. RESULTS Stratified spline regression analysis demonstrated that among those with severe depressive symptoms, perceived racism was not associated with PTB. However, perceived racism was significantly associated with PTB among women with mild to moderate (CES-D score ≤ 22) depressive symptoms. Perceived racism was not associated with PTB among women with or without high amounts of perceived stress. CONCLUSIONS Our findings suggest that racism, at least in the form of racial micro aggressions, may not further impact a group already at high risk for PTB (those with severe depressive symptoms), but may increase the risk of PTB for women at lower baseline risk.

Racial and Ethnic Health Disparities and the Affordable Care Act: a Status Update.

Persistent racial and ethnic health disparities exist in the USA, despite decades of research and public health initiatives. Several factors contribute to health disparities, including (but not limited to) implicit provider bias, access to health care, social determinants, and biological factors. Disparities in health by race/ethnicity are unacceptable and correctable. The Patient Protection and Affordable Care Act is a comprehensive legislation that is focused on improving health care access, quality, and cost control. This health care reform includes specific provisions which focus on preventive care, the standardized collection of data on race, ethnicity, primary language and disability status, and health information technology. Although some provisions of the Patient Protection and Affordable Care Act have not been implemented, such as funding for the U.S. Public Health Sciences track, which would have addressed the shortage of medical professionals in the USA who are trained to use patient-centered, interdisciplinary, and care coordination approaches, this legislation is still poised to make great strides toward eliminating health disparities. The purpose of this manuscript is to highlight the unprecedented opportunities that exist for the Patient Protection and Affordable Care Act to reduce racial and ethnic disparities in health in the USA.

Antibody Levels to Persistent Pathogens and Incident Stroke in Mexican Americans

Background Persistent pathogens have been proposed as risk factors for stroke; however, the evidence remains inconclusive. Mexican Americans have an increased risk of stroke especially at younger ages, as well as a higher prevalence of infections caused by several persistent pathogens. Methodology/Principal Findings Using data from the Sacramento Area Latino Study on Aging (n = 1621), the authors used discrete-time regression to examine associations between stroke risk and (1) immunoglobulin G antibody levels to Helicobacter pylori (H. pylori), Cytomegalovirus, Varicella Zoster Virus, Toxoplasma gondii and Herpes simplex virus 1, and (2) concurrent exposure to several pathogens (pathogen burden), defined as: (a) summed sero-positivity, (b) number of pathogens eliciting high antibody levels, and (c) average antibody level. Models were adjusted for socio-demographics and stroke risk factors. Antibody levels to H. pylori predicted incident stroke in fully adjusted models (Odds Ratio: 1.58; 95% Confidence Interval: 1.09, 2.28). No significant associations were found between stroke risk and antibody levels to the other four pathogens. No associations were found for pathogen burden and incident stroke in fully adjusted models. Conclusions/Significance Our results suggest that exposure to H. pylori may be a stroke risk factor in Mexican Americans and may contribute to ethnic differences in stroke risk given the increased prevalence of exposure to H. pylori in this population. Future studies are needed to confirm this association.

Racial differences in oncogene mutations detected in early stage, low grade endometrial cancers

Objective To describe the pattern and frequency of oncogene mutations in white and African American women with endometrial cancer and to determine if racial differences in oncogene mutations exist among women with pathologically similar tumors. Methods Patients with endometrial cancer from a large urban hospital were identified through medical records, and representative formalin-fixed paraffin-embedded tumor blocks were retrieved. The study sample included 150 patients (84 African Americans) who underwent total abdominal hysterectomy for endometrial cancer. The Sequenom MassARRAY system and the OncoCarta Assay version 1.0 (Sequenom) were used to test for 238 mutations in 19 common oncogenes. The χ2 test and the Fisher exact test were used to assess differences in distribution of variables by race and oncogene mutation status. Results There were 20 mutations identified in 2 oncogenes (PIK3CA and KRAS) in tumors from 19 women (12.7%). Most of the mutations were found in PIK3CA (16/20). Thirteen percent of endometrioid tumors harbored mutations (11 PIK3CA and 2 KRAS) as did 29% of the malignant mixed Mullerian tumors (3 PIK3CA and 1 KRAS). There were no observed mutations in serous, clear cell, or mucinous tumor types. Among low-grade endometrioid cancers, tumors from African American patients were significantly associated with harboring either a KRAS or PIK3CA mutation (P = 0.04), with 7 PIK3CA mutations and all 4 KRAS mutations identified in African American women. Conclusions This study provides preliminary evidence that oncogene mutation frequency of some subtypes of histologically similar endometrial carcinoma differ by race. Additional studies are needed to further explore this phenomenon in patients with endometrial carcinoma.

Neighborhood Walkability and Adiposity in the Women’s Health Initiative Cohort

INTRODUCTION Neighborhood environments may play a role in the rising prevalence of obesity among older adults. However, research on built environmental correlates of obesity in this age group is limited. The current study aimed to explore associations of Walk Score, a validated measure of neighborhood walkability, with BMI and waist circumference in a large, diverse sample of older women. METHODS This study linked cross-sectional data on 6,526 older postmenopausal women from the Womens Health Initiative Long Life Study (2012-2013) to Walk Scores for each participants address (collected in 2012). Linear and logistic regression models were used to estimate associations of BMI and waist circumference with continuous and categorical Walk Score measures. Secondary analyses examined whether these relationships could be explained by walking expenditure or total physical activity. All analyses were conducted in 2015. RESULTS Higher Walk Score was not associated with BMI or overall obesity after adjustment for sociodemographic, medical, and lifestyle factors. However, participants in highly walkable areas had significantly lower odds of abdominal obesity (waist circumference >88 cm) as compared with those in less walkable locations. Observed associations between walkability and adiposity were partly explained by walking expenditure. CONCLUSIONS Findings suggest that neighborhood walkability is linked to abdominal adiposity, as measured by waist circumference, among older women and provide support for future longitudinal research on associations between Walk Score and adiposity in this population.

Linking Nontraditional Physical Activity and Preterm Delivery in Urban African-American Women

BACKGROUND Traditional risk factors for preterm delivery (PTD) do not account for the disparate rates among African-American women. Physical activity during pregnancy may protect women from PTD, but few studies exist in African Americans. Our objective was to examine the relationships between PTD and intensity and duration of leisure time physical activity (LTPA) as well as non-LTPA such as stair climbing and walking for a purpose during pregnancy. METHODS Data were from a hybrid retrospective/prospective cohort study of urban low-income African-American women enrolled from 2001 to 2004 in the Baltimore PTD Study (n = 832). PTD was defined as birth before 37 completed weeks of gestation. Study participants reported physical activity during prenatal (n = 456) and post-partum (n = 376) interviews. FINDINGS The rate of PTD was 16.7%. In unadjusted log-binomial regression models, we found no significant associations. However, in models adjusted for illicit drug use, locus of control, and a validated family resources scale, we found a significant decrease in prevalence of PTD for women who walked for a purpose more than 30 min/d (prevalence ratio, 0.64; 95% CI, 0.43-0.94), compared with women who walked less than or equal to 30 min/d. CONCLUSIONS These results suggest that walking for a purpose during pregnancy may confer protection against PTD among urban low-income African Americans.