Last data update: May 13, 2024. (Total: 46773 publications since 2009)
Records 1-7 (of 7 Records) |
Query Trace: Chin HB[original query] |
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Environmental phenol exposures in 6- to 12-week-old infants: the Infant Feeding and Early Development (IFED) Study
Goldberg M , Adgent MA , Stevens DR , Chin HB , Ferguson KK , Calafat AM , Travlos G , Ford EG , Stallings VA , Rogan WJ , Umbach DM , Baird DD , Sandler DP . Environ Res 2024 119075 BACKGROUND: Exposure to phenols, endocrine-disrupting chemicals used in personal care and consumer products, is widespread. Data on infant exposures are limited despite heightened sensitivity to endocrine disruption during this developmental period. We aimed to describe distributions and predictors of urinary phenol concentrations among U.S. infants ages 6-12 weeks. METHODS: The Infant Feeding and Early Development (IFED) study is a prospective cohort study of healthy term infants enrolled during 2010-2013 in the Philadelphia region. We measured concentrations of seven phenols in 352 urine samples collected during the 6- or 8- and/or 12-week study visits from 199 infants. We used linear mixed models to estimate associations of maternal, sociodemographic, infant, and sample characteristics with natural-log transformed, creatinine-standardized phenol concentrations and present results as mean percent change from the reference level. RESULTS: Median concentrations (μg/L) were 311 for methylparaben, 10.3 for propylparaben, 3.6 for benzophenone-3, 2.1 for triclosan, 1.0 for 2,5-dichlorophenol, 0.7 for BPA, and 0.3 for 2,4-dichlorophenol. Geometric mean methylparaben concentrations were approximately 10 times higher than published estimates for U.S. children ages 3-5 and 6-11 years, while propylparaben concentrations were 3-4 times higher. Infants of Black mothers had higher concentrations of BPA (83%), methylparaben (121%), propylparaben (218%), and 2,5-dichorophenol (287%) and lower concentrations of benzophenone-3 (-77%) and triclosan (-53%) than infants of White mothers. Triclosan concentrations were higher in breastfed infants (176%) and lower in infants whose mothers had a high school education or less (-62%). Phenol concentrations were generally higher in summer samples. CONCLUSIONS: Widespread exposure to select environmental phenols among this cohort of healthy U.S. infants, including much higher paraben concentrations compared to those reported for U.S. children, supports the importance of expanding population-based biomonitoring programs to infants and toddlers. Future investigation of exposure sources is warranted to identify opportunities to minimize exposures during these sensitive periods of development. |
Reproductive hormone concentrations and associated anatomical responses: does soy formula affect minipuberty in boys
Chin HB , Kelly A , Adgent MA , Patchel SA , James K , Vesper HW , Botelho JC , Chandler DW , Zemel BS , Schall JI , Ford EG , Darge K , Stallings VA , Baird DD , Rogan WJ , Umbach DM . J Clin Endocrinol Metab 2021 106 (9) 2635-2645 CONTEXT: Soy formula feeding is common in infancy and is a source of high exposure to phytoestrogens, documented to influence vaginal cytology in female infants. Its influence on minipuberty in males has not been established. OBJECTIVE: To assess the association between infant feeding practice and longitudinally measured reproductive hormones and hormone-responsive tissues in infant boys. DESIGN: The Infant Feeding and Early Development study was a prospective cohort of maternal-infant dyads requiring exclusive soy formula, cow-milk formula, or breastmilk feeding during study follow-up. Reproductive hormone concentrations and male anatomical measurements were longitudinally assessed from birth to 28 weeks. SETTING: Clinic-based cohort. PARTICIPANTS: 147 mother-infant boy pairs. INTERVENTIONS: not applicable. MAIN OUTCOME MEASURE: Serum testosterone and luteinizing hormone (LH) concentrations, stretched penile length, anogenital distance, and testis volume. RESULTS: Median serum testosterone was at pubertal levels at 2 weeks [176 ng/dL (quartiles:124, 232)] and remained in this range until 12 weeks, in all feeding groups. We did not observe differences in trajectories of hormone concentrations or anatomical measures between boys fed soy formula (n=55) and boys fed cow-milk formula (n=54). Compared with breastfed boys (n=38), soy-formula-fed boys had a more rapid increase in penile length (p=0.004) and slower initial lengthening of AGD (p=0.03), but no differences in hormone trajectories. CONCLUSIONS: Reproductive hormone concentrations and anatomical responses followed similar trajectories in soy and cow-milk formula-fed infant boys. Our findings suggest that these measures of early male reproductive development do not respond to phytoestrogen exposure during infancy. |
Improving diversity and promoting inclusion in the society for epidemiologic research through choice of conference location
Johnson CY , Chin HB . Am J Epidemiol 2020 189 (10) 1030-1032 Scientific conferences provide attendees opportunities to network, share research, learn new skills and ideas, and initiate collaborations. Conference attendance is especially important for students and early career researchers who are establishing their research careers or looking for jobs. However, attending conferences can be expensive, and the high cost of conference attendance may hit students and early career researchers the hardest. According to a new member survey from the Society for Epidemiologic Research, early career members are more racially and ethnically diverse than senior members, meaning that reducing financial barriers to conference participation may be an important consideration for increasing diversity among conference attendees. In this commentary, we discuss how choice of conference location-choosing less expensive cities nearer to more Society for Epidemiologic Research members-could reduce financial and other barriers to conference attendance for all members and improve diversity and inclusion in the Society. |
Association of urinary concentrations of early pregnancy phthalate metabolites and bisphenol A with length of gestation
Chin HB , Jukic AM , Wilcox AJ , Weinberg CR , Ferguson KK , Calafat AM , McConnaughey DR , Baird DD . Environ Health 2019 18 (1) 80 BACKGROUND: Environmental exposure to phthalates and bisphenol A (BPA) may have endocrine disrupting effects that alter length of gestation. We assessed the association between the urinary concentrations of 11 phthalate metabolites and BPA with length of gestation in a cohort of women followed from before conception with daily 1st-morning urinary hormone measures that identified day of implantation. METHODS: Pre-implantation and post-implantation urinary phthalate metabolites and BPA concentrations were measured in pooled urine samples designed to limit single-measure variability due to the likely episodic nature of these exposures and the short half-life of these compounds. We estimated associations between these exposure biomarkers early in pregnancy with length of gestation from implantation to spontaneous birth. Cox proportional hazards models were used to estimate the hazard of birth among 125 naturally-conceived, singleton live births with censoring for medical interventions that artificially shortened pregnancy. RESULTS: Higher concentrations of mono (2-ethyl-5-hydroxyhexyl) phthalate (a metabolite of di (2-ethylhexyl) phthalate (DEHP)) during the pre-implantation window were associated with reduced probability of birth, i.e., longer gestations (hazard ratio (HR): 0.55, 95% CI: 0.35, 0.86; p = 0.01). The HR for the molar sum of the four DEHP metabolites measured showed a similar association (HR: 0.67, 95% CI: 0.43, 1.05). Higher concentrations of mono (3-carboxypropyl) phthalate (MCPP), a non-specific metabolite of several high molecular-weight phthalates, measured post-implantation were associated with increased risk of earlier birth, i.e. shorter length of gestation, HR: 1.59, CI: 1.02, 2.49. CONCLUSIONS: Early gestational exposure to DEHP and possibly other high-molecular weight phthalates, (as reflected by urinary MCPP concentrations) may influence the length of pregnancy. Such effects could have consequences for neonatal and maternal health. |
Association of urinary concentrations of phthalate metabolites and bisphenol A with early pregnancy endpoints
Chin HB , Jukic AM , Wilcox AJ , Weinberg CR , Ferguson KK , Calafat AM , McConnaughey DR , Baird DD . Environ Res 2018 168 254-260 BACKGROUND: Phthalates and bisphenol A (BPA) are environmental contaminants that may affect early embryonic development. OBJECTIVE: To assess the association between phthalate metabolites and BPA with early pregnancy endpoints in a cohort of women followed from before conception. METHODS: We quantified 11 phthalate metabolites and BPA in 137 conception cycles from naturally conceived clinical pregnancies. Phthalate metabolites and BPA concentrations were measured in a pooled sample of three daily morning urine specimens. Daily urinary hormone measurements had previously been used to define ovulation, implantation, and corpus luteum rescue. We assessed associations between conception cycle exposures (phthalate biomarkers and BPA) and 1) time from ovulation to implantation; 2) type of corpus luteum rescue (timing and pattern of rise in progesterone: early, late, or no rise); and 3) rate of initial rise in hCG. RESULTS: Mono(3-carboxypropyl) phthalate (MCPP) and mono-isobutyl phthalate (MiBP) were associated with earlier implantation (6-8 days vs. 9 days (the most commonly observed); per natural log-unit, OR (95% CI) =2.8 (1.2, 6.7) and OR (CI) =2.1 (1.2, 3.7), respectively). Monoethyl phthalate (MEP) was associated with later implantation (10-12 days vs. 9 days); OR (CI) =1.5 (1.0, 2.1). Compared with implantation on day 9, BPA was significantly associated with both earlier and later implantation (OR=2.2 for both). Women with concentrations above the median of monobenzyl phthalate (MBzP) (p=0.04) or above the median of the molar sum of four di(2-ethylhexyl) phthalate metabolites ( summation operatorDEHP) (p=0.08) had a slower initial rise in hCG. Increasing MCPP was associated with an increased odds of a late rise rescue (OR (CI) =2.9 (1.0, 8.5); late rise vs. early rise), while increasing MEP was associated with a no rise rescue (OR (CI) =1.6 (0.9, 2.8); no rise vs. early rise). CONCLUSIONS: The reported associations varied in their direction of effect, some potentially protective, others adverse. This may reflect the complexity with which these potential endocrine disrupting chemicals can be acting, but chance findings are also possible. Given that women continue to be exposed to these compounds (or their precursors), continued research on the effects they may have on pregnancy is warranted. |
Methods for conducting community guide systematic reviews of evidence on effectiveness and economic efficiency of group-based behavioral interventions to prevent adolescent pregnancy, human immunodeficiency virus, and other sexually transmitted infections: comprehensive risk reduction and abstinence education
Sipe TA , Chin HB , Elder R , Mercer SL , Chattopadhyay SK , Jacob V , Community Preventive Services Task Force . Am J Prev Med 2012 42 (3) 295-303 This paper describes methods used to conduct systematic reviews and meta-analyses and economic reviews of group-based behavioral interventions for adolescents to prevent pregnancy, HIV, and other sexually transmitted infections. The steps described include developing a conceptual approach, defining the interventions, identifying outcome and moderator variables, searching the literature, abstracting the data, and analyzing the results. In addition, identification of potential harms and benefits, applicability of results, barriers to implementation, and research gaps are described. |
The effectiveness of group-based comprehensive risk-reduction and abstinence education interventions to prevent or reduce the risk of adolescent pregnancy, human immunodeficiency virus, and sexually transmitted infections: two systematic reviews for the Guide to Community Preventive Services
Chin HB , Sipe TA , Elder R , Mercer SL , Chattopadhyay SK , Jacob V , Wethington HR , Kirby D , Elliston DB , Griffith M , Chuke SO , Briss SC , Ericksen I , Galbraith JS , Herbst JH , Johnson RL , Kraft JM , Noar SM , Romero LM , Santelli J , Community Preventive Services Task Force . Am J Prev Med 2012 42 (3) 272-94 CONTEXT: Adolescent pregnancy, HIV, and other sexually transmitted infections (STIs) are major public health problems in the U.S. Implementing group-based interventions that address the sexual behavior of adolescents may reduce the incidence of pregnancy, HIV, and other STIs in this group. EVIDENCE ACQUISITION: Methods for conducting systematic reviews from the Guide to Community Preventive Services were used to synthesize scientific evidence on the effectiveness of two strategies for group-based behavioral interventions for adolescents: (1) comprehensive risk reduction and (2) abstinence education on preventing pregnancy, HIV, and other STIs. Effectiveness of these interventions was determined by reductions in sexual risk behaviors, pregnancy, HIV, and other STIs and increases in protective sexual behaviors. The literature search identified 6579 citations for comprehensive risk reduction and abstinence education. Of these, 66 studies of comprehensive risk reduction and 23 studies of abstinence education assessed the effects of group-based interventions that address the sexual behavior of adolescents, and were included in the respective reviews. EVIDENCE SYNTHESIS: Meta-analyses were conducted for each strategy on the seven key outcomes identified by the coordination team-current sexual activity; frequency of sexual activity; number of sex partners; frequency of unprotected sexual activity; use of protection (condoms and/or hormonal contraception); pregnancy; and STIs. The results of these meta-analyses for comprehensive risk reduction showed favorable effects for all of the outcomes reviewed. For abstinence education, the meta-analysis showed a small number of studies, with inconsistent findings across studies that varied by study design and follow-up time, leading to considerable uncertainty around effect estimates. CONCLUSIONS: Based on these findings, group-based comprehensive risk reduction was found to be an effective strategy to reduce adolescent pregnancy, HIV, and STIs. No conclusions could be drawn on the effectiveness of group-based abstinence education. |
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