Faculty Bibliography

CONTEXT/BACKGROUND:Phthalates are commonly found in commercial packaging, solvents, vinyl, and personal care products, and there is concern for potential endocrine-disrupting effects in males. The commonly used di-2-ethylhexyl phthalate (DEHP) has progressively been replaced by seldom studied compounds, such as bis-2-ethylhexyl terephthalate and 1,2-cyclohexane dicarboxylic acid di-isononyl ester (DINCH). OBJECTIVE:To investigate the associations between the urinary phthalate metabolites and serum sex steroid hormone concentrations in a nationally representative sample of adult males. DESIGN, SETTING, PARTICIPANTS, AND INTERVENTION/UNASSIGNED:This was a cross-sectional analysis of data from the 2013-2016 National Health and Nutrition Examination Survey among 1420 male participants aged ≥20 years. MAIN OUTCOME MEASURES/METHODS:Serum levels of total testosterone, estradiol, sex hormone binding globulin, and derived sex hormone measurements of free testosterone, bioavailable testosterone, and free androgen index were examined as log-transformed continuous variables. RESULTS:Phthalate metabolites were not statistically significantly associated with sex hormone concentrations among all men. However, associations varied by age. High molecular weight phthalates were associated with lower total, free, and bioavailable testosterone among men age ≥60. Specifically, each doubling of ΣDEHP was associated with 7.72% lower total testosterone among older men (95% Confidence Interval: -12.76%, -2.39%). Low molecular phthalates were associated with lower total, free, and bioavailable testosterone among men age 20-39 and ΣDINCH was associated with lower total testosterone among men age ≥40. CONCLUSIONS:Our results indicate that males may be vulnerable to different phthalate metabolites in age-specific ways. These results support further investigation into the endocrine-disrupting effects of phthalates.

Identifying skills at entry to school that promote academic success has been a major goal for policy and research. The current study categorized school-entry skills as academic (i.e., math and reading skills), cognitive (i.e., language and executive functioning), and social-emotional (i.e., externalizing and internalizing problems) skills and asked to what extent each predicted school-age skills. Data were drawn from the Family Life Project, a representative birth cohort study of 1292 children living in low-wealth rural communities. Children's academic, cognitive, and social-emotional skills were assessed prior to kindergarten and used to predict longitudinal trajectories in math, reading, language, and social-emotional skills from kindergarten through third grade. Findings indicate that school-entry skills within a given domain were the strongest predictor of the level of school-age skills within that domain, but the magnitude of those associations diminished over time. Higher levels of language and executive function, and lower levels of internalizing problems were the only school-entry skills to predict larger gains in skills during the first four years of elementary school. These results suggest that greater focus on both cognitive and social-emotional skills during early childhood may be warranted.

BACKGROUND:Several distinct plant-based diet indices (PDIs) have been developed to characterize adherence to plant-based diets. OBJECTIVE:We contrasted 5 PDIs in a community-based cohort by assessing characteristics of the diet and evaluating whether these PDIs are associated with risk of incident hypertension. METHODS:Using FFQ data from adults (45-64 y, n = 8041) without hypertension at baseline in the Atherosclerosis Risk in Communities (ARIC) Study, we scored participants' diets using the overall PDI (oPDI), healthy PDI (hPDI), less healthy (unhealthy) PDI (uPDI), provegetarian diet index, and PDI from the Rotterdam Study (PDI-Rotterdam). For the oPDI, provegetarian diet, and PDI-Rotterdam, higher intakes of all or selected plant foods received higher scores. For the hPDI, higher intakes of plant foods identified as healthful received higher scores. For the uPDI, higher intakes of less healthy plant foods received higher scores. All indices scored higher intakes of animal foods lower. We examined agreement between indices, and whether scores on these indices were associated with risk of hypertension using Cox proportional hazard models. RESULTS:The PDIs were moderately-to-strongly correlated and largely ranked subjects consistently, except for the uPDI. Over a median follow-up of 13 y, 6044 incident hypertension cases occurred. When adjusted for sociodemographic characteristics, other dietary factors, and health behaviors, the highest compared with the lowest quintile for adherence to the oPDI, hPDI, and provegetarian diet was associated with a 12-16% lower risk of hypertension (all P-trend <0.05). Highest adherence to the uPDI was associated with a 13% higher risk of hypertension, when clinical factors were further adjusted for (P-trend = 0.03). No significant association was observed with the PDI-Rotterdam. The oPDI, hPDI, and provegetarian diet moderately improved the prediction of hypertension. CONCLUSIONS:In middle-aged US adults, despite moderate agreement in ranking subjects across PDIs, operational differences can affect the ability to detect diet-disease associations, such as hypertension.

INTRODUCTION/BACKGROUND:In the USA, transgender women are among the most vulnerable to HIV. In particular, transgender women of colour face high rates of infection and low uptake of important HIV prevention tools, including pre-exposure prophylaxis (PrEP). This paper describes the design, sampling methods, data collection and analyses of the TURNNT ('Trying to Understand Relationships, Networks and Neighbourhoods among Transgender women of colour') study. In collaboration with communities of transgender women of colour, TURNNT aims to explore the complex social and environmental (ie, neighbourhood) structures that affect HIV prevention and other aspects of health in order to identify avenues for intervention. METHODS AND ANALYSES/UNASSIGNED:TURNNT is a prospective cohort study, which will recruit 300 transgender women of colour (150 Black/African American, 100 Latina and 50 Asian/Pacific Islander participants) in New York City. There will be three waves of data collection separated by 6 months. At each wave, participants will provide information on their relationships, social and sexual networks, and neighbourhoods. Global position system technology will be used to generate individual daily path areas in order to estimate neighbourhood-level exposures. Multivariate analyses will be conducted to assess cross-sectional and longitudinal, independent and synergistic associations of personal relationships (notably individual social capital), social and sexual networks, and neighbourhood factors (notably neighbourhood-level social cohesion) with PrEP uptake and discontinuation. ETHICS AND DISSEMINATION/UNASSIGNED:The TURNNT protocol was approved by the Columbia University Institutional Review Board (reference no. AAAS8164). This study will provide novel insights into the relationship, network and neighbourhood factors that influence HIV prevention behaviours among transgender women of colour and facilitate exploration of this population's health and well-being more broadly. Through community-based dissemination events and consultation with policy makers, this foundational work will be used to guide the development and implementation of future interventions with and for transgender women of colour.

An increasing number of young children nationally participate in preschool education, yet very little is known about the influence of peers' behavioral regulation, such as maintaining focus on a task in the face of distractions and inhibiting a dominant response (attentionimpulse control), and remembering instructions (engagement) on children's motor-cognitive readiness skills (i.e., peer effects). This study determined whether peer effects are present in this earliest sector of schooling. Research has shown that a child's own behavioral regulation is associated with his or her academic outcomes. However, not much is known about how children are affected by classmates with poor behavioural regulation. This study begins to fill the gaps in our understanding of preschool peer effects in the form of peers' behavioral regulation relative to children's motor-cognitive readiness skills. It addresses two research questions: (1) Is the average level and amount of variation of peers' behavioral regulation skills (i.e., engagement and attentionimpulse control) in a classroom associated with growth in children's motor-cognitive readiness outcomes in preschool (motor, content knowledge, and language)? (2) Do these associations differ for children with high and low initial levels of behavioral regulation? The analytic sample is drawn from a cluster (school) randomized controlled trial testing a family-centered, school-based intervention (N=1050 children in 99 classrooms drawn from 10 high-poverty schools). Results indicated that classroom-level peer engagement skills made a unique contribution to children's growth of motor skills during the preschool academic year. Furthermore, children with higher engagement skills at the beginning of the preschool year had higher motor-cognitive readiness skills (motor, content knowledge, and language) at the end of the year when they were in classrooms with peers with high engagement skills. This study extends previous work with older children and indicates that after adjusting for an assortment of demographic, preschool program-related factors, and motor-cognitive readiness at entry into preschool, peers' engagement skills may make a unique contribution to children's motor-cognitive readiness skills during the preschool academic year.

This study evaluated the safety of early anti-factor Xa assay-guided enoxaparin dosing for chemoprophylaxis in patients with TBI. We hypothesized that assay-guided chemoprophylaxis would be comparable in the risk of intracranial hemorrhage (ICH) progression to fixed dosing. An observational analysis of adult patients with blunt traumatic brain injury (TBI) was performed at a Level I trauma center from August 2016 to September 2017. Patients in the assay-guided group were treated with an initial enoxaparin dose of 0.5 mg/kg, with peak anti-factor Xa activity measured four hours after the third dose. Prophylactic range was defined as 0.2 to 0.5 IU/mL with a dose adjustment of ± 10 mg based on the assay result. The assay-guided group was compared with historical fixed-dose controls and to a TBI cohort from the most recent Trauma Quality Improvement Project dataset. Of 179 patients included in the study, 85 were in the assay-guided group and 94 were in the fixed-dose group. Compared with the fixed-dose group, the assay-guided group had a lower Glasgow Coma Score and higher Injury Severity Score. The proportion of severe (Abbreviated Injury Score, head ≥3) TBI, ICH progression, and venous thromboembolism rates were similar between all groups. The assay-guided and fixed-dose groups had chemoprophylaxis initiated earlier than the Trauma Quality Improvement Project group. The assay-guided group had the highest percentage of low molecular weight heparin use. Early initiation of enoxaparin anti-factor Xa assay-guided venous thromboembolism chemoprophylaxis has a comparable risk of ICH progression to fixed dosing in patients with TBI. These findings should be validated prospectively in a multicenter study.