Brisa N. Sánchez

Relation between Neighborhood Environments and Obesity in the Multi-Ethnic Study of Atherosclerosis

This study investigated associations between neighborhood physical and social environments and body mass index in 2,865 participants of the Multi-Ethnic Study of Atherosclerosis (MESA) aged 45-84 years and residing in Maryland, New York, and North Carolina. Neighborhood (census tract) environments were measured in non-MESA participants residing in MESA neighborhoods (2000-2002). The neighborhood physical environment score combined measures of a better walking environment and greater availability of healthy foods. The neighborhood social environment score combined measures of greater aesthetic quality, safety, and social cohesion and less violent crime. Marginal maximum likelihood was used to estimate associations between neighborhood environments and body mass index (kg/m(2)) before and after adjustment for individual-level covariates. MESA residents of neighborhoods with better physical environments had lower body mass index (mean difference per standard deviation higher neighborhood measure = -2.38 (95% confidence interval (CI): -3.38, -1.38) kg/m(2) for women and -1.20 (95% CI: -1.84, -0.57) kg/m(2) for men), independent of age, race/ethnicity, education, and income. Attenuation of these associations after adjustment for diet and physical activity suggests a mediating role of these behaviors. In men, the mean body mass index was higher in areas with better social environments (mean difference = 0.52 (95% CI: 0.07, 0.97) kg/m(2)). Improvement in the neighborhood physical environment should be considered for its contribution to reducing obesity.

Influence of prenatal lead exposure on genomic methylation of cord blood DNA.

Background Fetal lead exposure is associated with adverse pregnancy outcomes and developmental and cognitive deficits; however, the mechanism(s) by which lead-induced toxicity occurs remains unknown. Epigenetic fetal programming via DNA methylation may provide a pathway by which environmental lead exposure can influence disease susceptibility. Objective This study was designed to determine whether prenatal lead exposure is associated with alterations in genomic methylation of leukocyte DNA levels from umbilical cord samples. Methods We measured genomic DNA methylation, as assessed by Alu and LINE-1 (long interspersed nuclear element-1) methylation via pyrosequencing, on 103 umbilical cord blood samples from the biorepository of the Early Life Exposures in Mexico to Environmental Toxicants (ELEMENT) study group. Prenatal lead exposure had been assessed by measuring maternal bone lead levels at the mid-tibial shaft and the patella using a spot-source 109Cd K-shell X-ray fluorescence instrument. Results We found an inverse dose–response relationship in which quartiles of patella lead correlated with cord LINE-1 methylation (p for trend = 0.01) and and tibia lead correlated with Alu methylation (p for trend = 0.05). In mixed effects regression models, maternal tibia lead was negatively associated with umbilical cord genomic DNA methylation of Alu (β= −0.027; p = 0.01). We found no associations between cord blood lead and cord genomic DNA methylation. Conclusions Prenatal lead exposure is inversely associated with genomic DNA methylation in cord blood. These data suggest that the epigenome of the developing fetus can be influenced by maternal cumulative lead burden, which may influence long-term epigenetic programming and disease susceptibility throughout the life course.

Socioeconomic and race/ethnic differences in daily salivary cortisol profiles: The Multi-Ethnic Study of Atherosclerosis

It has often been hypothesized that stress and its biological consequences mediate the relationship between low socioeconomic status (SES) or minority status and poor cardiovascular disease outcomes. The objective of this study was to determine if daily cortisol patterns, a biomarker of the stress response, differ by race/ethnicity and socioeconomic status. Data were collected from 935 Black, White and Hispanic adults age 48-90 years old. Salivary cortisol samples were collected six times per day over 3 days: at awakening, 30min later, at 1000h, noon, 1800h and at bedtime. Blacks and Hispanics had lower levels of wake-up cortisol and less steep early declines, while Blacks had flatter and Hispanics steeper late day declines relative to Whites. Similarly the low socioeconomic status group also had lower levels of wake-up cortisol and less steep decline during the early part of the day. These patterns remained after adjustment for health behaviors and psychosocial factors. This study finds an association between salivary cortisol and race/ethnicity and SES in a multi-ethnic study population. Further work is needed to determine the health consequences of these differences.

Bisphenol a exposure in Mexico City and risk of prematurity: a pilot nested case control study

BackgroundPresence of Bisphenol A (BPA) has been documented worldwide in a variety of human biological samples. There is growing evidence that low level BPA exposure may impact placental tissue development and thyroid function in humans. The aim of this present pilot study was to determine urinary concentrations of BPA during the last trimester of pregnancy among a small subset of women in Mexico City, Mexico and relate these concentrations to risk of delivering prematurely.MethodsA nested case-control subset of 60 participants in the Early Life Exposure in Mexico to ENvironmental Toxicants (ELEMENT) study in Mexico City, Mexico were selected based on delivering less than or equal to 37 weeks of gestation and greater than 37 weeks of gestation. Third trimester archived spot urine samples were analyzed by online solid phase extraction coupled with high performance liquid chromatography isotope dilution tandem mass spectrometry.ResultsBPA was detected in 80.0% (N = 48) of the urine samples; total concentrations ranged from < 0.4 μg/L to 6.7 μg/L; uncorrected geometric mean was 1.52 μg/L. The adjusted odds ratio of delivering less than or equal to 37 weeks in relation to specific gravity adjusted third trimester BPA concentration was 1.91 (95%CI 0.93, 3.91, p-value = 0.08). When cases were further restricted to births occurring prior to the 37th week (n = 12), the odds ratio for specific-gravity adjusted BPA was larger and statistically significant (p < 0.05).ConclusionsThis is the first study to document measurable levels of BPA in the urine of a population of Mexican women. This study also provides preliminary evidence, based on a single spot urine sample collected during the third trimester, that pregnant women who delivered less than or equal to 37 weeks of gestation and prematurely (< 37 weeks) had higher urinary concentrations of BPA compared to women delivering after 37 weeks.

Exposure to Phthalates in Neonatal Intensive Care Unit Infants: Urinary Concentrations of Monoesters and Oxidative Metabolites

Objective We previously demonstrated that among 54 infants in neonatal intensive care units, exposure to polyvinyl chloride plastic medical devices containing the plasticizer di(2-ethylhexyl) phthalate (DEHP) is associated with urinary concentrations of mono(2-ethylhexyl) phthalate (MEHP), a DEHP metabolite. In this follow-up report, we studied the neonates’ exposure to DEHP-containing devices in relation to urinary concentrations of two other DEHP metabolites, and to urinary concentrations of metabolites of dibutyl phthalate (DBP) and benzylbutyl phthalate (BzBP), phthalates found in construction materials and personal care products. Measurements A priori, we classified the intensiveness of these 54 infants’ exposure to DEHP-containing medical products. We measured three metabolites of DEHP in infants’ urine: MEHP and two of its oxidative metabolites, mono(2-ethyl-5-hydroxylhexyl) phthalate (MEHHP) and mono(2-ethyl-5-oxohexyl) phthalate (MEOHP). We also measured monobutyl phthalate (MBP), a metabolite of DBP, and monobenzyl phthalate (MBzP), a metabolite of BzBP. Results Intensiveness of DEHP-containing product use was monotonically associated with all three DEHP metabolites. Urinary concentrations of MEHHP and MEOHP among infants in the high-DEHP-intensiveness group were 13–14 times the concentrations among infants in the low-intensiveness group (p ≤ 0.007). Concentrations of MBP were somewhat higher in the medium-and high-DEHP-intensiveness group; MBzP did not vary by product use group. Incorporating all phthalate data into a structural equation model confirmed the specific monotonic association between intensiveness of product use and biologic measures of DEHP. Conclusion Inclusion of the oxidative metabolites MEHHP and MEOHP strengthened the association between intensiveness of product use and biologic indices of DEHP exposure over that observed with MEHP alone.

Ambient air pollution and risk for ischemic stroke and transient ischemic attack

Data on the association between air pollution and cerebrovascular disease in the United States are limited. The objective of this study was to investigate the association between short‐term exposure to ambient air pollution and risk for ischemic cerebrovascular events in a US community.

Differential effect of birthplace and length of residence on body mass index (BMI) by education, gender and race/ethnicity.

Although birthplace and length of residence have been found to be associated with Body Mass Index (BMI)/obesity in the USA, their effects may not be the same across groups defined by education, gender and race/ethnicity. Using cross-sectional population based data from the 2001 California Health Interview Survey, we investigated the associations of birthplace and US length of residence with BMI, and whether the influence of birthplace-US length of residence on BMI varied by education, gender and race/ethnicity. Our sample included 37,350 adults aged 25-64 years. Self-reported weight and height were used to calculate BMI. Birthplace and length of residence were combined into a single variable divided into five levels: US-born, foreign-born living in the United States for more than 15, 10-14, 5-9, and less than 5 years. Controlling for age, gender, marital status, race/ethnicity, education, income, fruit and vegetable consumption, current smoking and alcohol use, we found that: (1) foreign-born adults had lower BMI than US-born adults; (2) among foreign-born adults, longer residence in the United States was associated with higher BMI; and (3) the effect of birthplace-length of US residence on BMI differed by education level, gender and race/ethnicity. Specifically, longer residence in the United States was associated with the greatest percent increases in BMI among the lowest educated groups than higher educated groups, among women (vs. men) and among Hispanics (vs. other racial/ethnic groups). These findings suggest that a protective effect of foreign birthplace on BMI appears to attenuate with length of residence in the United States, and also reveal that BMI/obesity trajectories associated with length of US residence vary by education, gender and race/ethnicity. Immigrant status, independently and in combination with education, gender and race/ethnicity should be considered in future obesity prevention and reduction efforts.

Do Socioeconomic Gradients in Body Mass Index Vary by Race/Ethnicity, Gender, and Birthplace?

Despite the well-documented negative socioeconomic status (SES) gradient in body mass index (BMI; weight (kg)/height (m)(2)) among women in developed societies, the presence and strength of the gradient is less consistent among men. Far less clear is the SES patterning of BMI among racial/ethnic minorities and immigrants. Using data from the 2001 California Health Interview Survey, a cross-sectional representative sample of California adults, the authors examined whether the SES patterning of BMI varied across 4 major US racial/ethnic groups (n = 37,150) by gender and birthplace. The shape and strength of the relation between SES and BMI differed markedly by race/ethnicity; and within racial/ethnic groups, it varied by gender. Irrespective of race/ethnicity, there were negative income and education gradients in BMI among women; however, there was considerable variation among men. The effect of education on BMI differed by birthplace in some groups. A clear education gradient in BMI was found among all US-born participants, a quadratic education pattern in BMI was found among foreign-born Asian men, a flat pattern was found among foreign-born Asian women, and no clear pattern was found in the remaining foreign-born groups. There is substantial heterogeneity in the contemporaneous SES gradient in BMI. US social disparities in BMI require simultaneous consideration of race/ethnicity and SES, but also birthplace.

Longitudinal Associations Between Neighborhood Physical and Social Environments and Incident Type 2 Diabetes Mellitus: The Multi-Ethnic Study of Atherosclerosis (MESA)

IMPORTANCE Neighborhood environments may influence the risk for developing type 2 diabetes mellitus (T2DM), but, to our knowledge, no longitudinal study has evaluated specific neighborhood exposures. OBJECTIVE To determine whether long-term exposures to neighborhood physical and social environments, including the availability of healthy food and physical activity resources and levels of social cohesion and safety, are associated with incident T2DM during a 10-year period. DESIGN, SETTING, AND PARTICIPANTS We used data from the Multi-Ethnic Study of Atherosclerosis, a population-based cohort study of adults aged 45 to 84 years at baseline (July 17, 2000, through August 29, 2002). A total of 5124 participants free of T2DM at baseline underwent 5 clinical follow-up examinations from July 17, 2000, through February 4, 2012. Time-varying measurements of neighborhood healthy food and physical activity resources and social environments were linked to individual participant addresses. Neighborhood environments were measured using geographic information system (GIS)- and survey-based methods and combined into a summary score. We estimated hazard ratios (HRs) of incident T2DM associated with cumulative exposure to neighborhood resources using Cox proportional hazards regression models adjusted for age, sex, income, educational level, race/ethnicity, alcohol use, and cigarette smoking. Data were analyzed from December 15, 2013, through September 22, 2014. MAIN OUTCOMES AND MEASURES Incident T2DM defined as a fasting glucose level of at least 126 mg/dL or use of insulin or oral antihyperglycemics. RESULTS During a median follow-up of 8.9 years (37,394 person-years), 616 of 5124 participants (12.0%) developed T2DM (crude incidence rate, 16.47 [95% CI, 15.22-17.83] per 1000 person-years). In adjusted models, a lower risk for developing T2DM was associated with greater cumulative exposure to indicators of neighborhood healthy food (12%; HR per interquartile range [IQR] increase in summary score, 0.88 [95% CI, 0.79-0.98]) and physical activity resources (21%; HR per IQR increase in summary score, 0.79 [95% CI, 0.71-0.88]), with associations driven primarily by the survey exposure measures. Neighborhood social environment was not associated with incident T2DM (HR per IQR increase in summary score, 0.96 [95% CI, 0.88-1.07]). CONCLUSIONS AND RELEVANCE Long-term exposure to residential environments with greater resources to support physical activity and, to a lesser extent, healthy diets was associated with a lower incidence of T2DM, although results varied by measurement method. Modifying neighborhood environments may represent a complementary, population-based approach to prevention of T2DM, although further intervention studies are needed.

Perinatal bisphenol A exposure promotes hyperactivity, lean body composition, and hormonal responses across the murine life course

The development of adult‐onset diseases is influenced by perinatal exposure to altered environmental conditions. One such exposure, bisphenol A (BPA), has been associated with obesity and diabetes, and consequently labeled an obesogen. Using an isogenic murine model, we examined the effects of perinatal exposure through maternal diet to 50 ng (n=20), 50 μg (n=21), or 50 mg (n=18) BPA/kg diet, as well as controls (n=20) on offspring energy expenditure, spontaneous activity, and body composition at 3, 6, and 9 mo of age, and hormone levels at 9 and 10 mo of age. Overall, exposed females and males exhibited increased energy expenditure (P<0.001 and 0.001, respectively) throughout the life course. In females, horizontal and vertical activity increased (P=0.07 and 0.06, respectively) throughout the life course. Generally, body composition measures were not different throughout the life course in exposed females or males (all P>0.44), although body fat and weight decreased in exposed females at particular ages (all P<0.08). Milligram‐exposed females had improved glucose, insulin, adiponectin, and leptin profiles (all P<0.10). Thus, life‐course analysis illustrates that BPA is associated with hyperactive and lean phenotypes. Variability across studies may be attributable to differential exposure duration and timing, dietary fat and phytoestrogen content, or lack of sophisticated phenotyping across the life course.—Anderson, O.S., Peterson, K.E., Sanchez, B.N., Zhang, Z., Mancuso, P., Dolinoy, D.C. Perinatal bisphenol A exposure promotes hyperactivity, lean body composition, and hormonal responses across the murine life course. FASEB J. 27, 1784–1792 (2013). www.fasebj.org