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Assessing Endogenous and Exogenous Hormone Exposures and Breast Development in a Migrant Study of Bangladeshi and British Girls.

ABSTRACT: Timing of breast development (or thelarche) and its endogenous and exogenous determinants may underlie global variation in breast cancer incidence. The study objectives were to characterize endogenous estrogen levels and bisphenol A (BPA) exposure using a migrant study of adolescent girls and test whether concentrations explained differences in thelarche by birthplace and growth environment. Estrogen metabolites (EM) and BPA-glucuronide (BPA-G) were quantified in urine spot samples using liquid chromatography tandem mass spectrometry (LC-MS/MS) from a cross-sectional study of Bangladeshi, first- and second-generation Bangladeshi migrants to the UK, and white British girls aged 5-16 years (n = 348). Thelarche status at the time of interview was self-reported and defined equivalent to Tanner Stage ?2. We compared geometric means (and 95% confidence interval (CIs)) of EM and BPA-G using linear regression and assessed whether EM and BPA-G explained any of the association between exposure to the UK and the age at thelarche using hazard ratios and 95% confidence intervals. Average EM decreased with exposure to the UK, whereas BPA-G increased and was significantly higher among white British (0.007 ng/mL, 95% CI: 0.0024-0.0217) and second-generation British-Bangladeshi girls (0.009 ng/mL, 95% CI: 0.0040-0.0187) compared to Bangladeshi girls (0.002 ng/mL, 95% CI: 0.0018-0.0034). Two of four EM ratios (16-pathway/parent and parent/all pathways) were significantly associated with thelarche. The relationship between exposure to the UK and thelarche did not change appreciably after adding EM and BPA-G to the models. While BPA-G is often considered a ubiquitous exposure, our findings suggest it can vary based on birthplace and growth environment, with increasing levels for girls who were born in or moved to the UK. Our study did not provide statistically significant evidence that BPA-G or EM concentrations explained earlier thelarche among girls who were born or raised in the UK.

SUBMITTER: Howland RE

PROVIDER: S-EPMC7068451 | biostudies-literature | 2020 Feb

REPOSITORIES: biostudies-literature

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Assessing Endogenous and Exogenous Hormone Exposures and Breast Development in a Migrant Study of Bangladeshi and British Girls.

Howland Renata E RE Deziel Nicole C NC Bentley Gillian R GR Booth Mark M Choudhury Osul A OA Hofmann Jonathan N JN Hoover Robert N RN Katki Hormuzd A HA Trabert Britton B Fox Stephen D SD Troisi Rebecca R Houghton Lauren C LC

International journal of environmental research and public health 20200213 4

Timing of breast development (or thelarche) and its endogenous and exogenous determinants may underlie global variation in breast cancer incidence. The study objectives were to characterize endogenous estrogen levels and bisphenol A (BPA) exposure using a migrant study of adolescent girls and test whether concentrations explained differences in thelarche by birthplace and growth environment. Estrogen metabolites (EM) and BPA-glucuronide (BPA-G) were quantified in urine spot samples using liquid ...[more]

PMID: 32069802

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Project description:BackgroundAdrenarche is a key early life event that marks middle childhood at approximately 7 years of age. Earlier work with British-Bangladeshi migrant women suggested that environmental conditions experienced before adrenarche influence adult reproductive function. We therefore investigated whether Bangladeshi children who migrate to the United Kingdom (UK) reach adrenarche earlier than non-migrants in Bangladesh or the United Kingdom.Methods and findingsHealthy girls, aged 5-16 years, were recruited from schools in Sylhet, Bangladesh and London, England comprising four groups: Sylhetis (n?=?165), first-generation migrants to the United Kingdom (n?=?42), second-generation girls (n?=?162), and British girls of European origin (n?=?50). Anthropometric measurements were collected together with questionnaire data for migration and socioeconomic characteristics. Saliva samples were assayed for dehydroepiandrosterone (DHEAS) using enzyme-linked immunosorbent assays. Multiple linear regressions tested for group differences in anthropometric and socioeconomic variables and DHEAS levels. Median ages at adrenarche (DHEAS>400 pg/ml) were estimated using Weibull regression models for parametric survival analysis. Hazard ratios for reaching adrenarche earlier and 95% confidence intervals (CI), both unadjusted and adjusted for anthropometric variables, were estimated from the survival analyses. First-generation migrants had a median age at adrenarche (5.3 years) that was significantly earlier than Sylheti (7.2), second-generation (7.4), and European (7.1) girls. In univariate analyses, first-generation girls reached adrenarche significantly earlier than Sylhetis [HR (CI): 2.8 (1.4-5.5]. In multivariate models, first generation girls still reached adrenarche earlier than Sylhetis after adjusting for height [HR(CI): 1.9 (0.9-4.1)] and weight [HR(CI):1.7 (0.8-3.8)], but these results were attenuated.ConclusionsWe suggest that rapid catch-up growth experienced by first generation girls during early childhood may explain their advanced adrenarche. The environmental conditions leading to an earlier adrenarche, as well as the health implications of this early transition, merit further exploration.

Project description:Background and objectivesLow levels of vitamin D among dark-skinned migrants to northern latitudes and increased risks for associated pathologies illustrate an evolutionary mismatch between an environment of high ultraviolet (UV) radiation to which such migrants are adapted and the low UV environment to which they migrate. Recently, low levels of vitamin D have also been associated with higher risks for contracting COVID-19. South Asians in the UK have higher risk for low vitamin D levels. In this study, we assessed vitamin D status of British-Bangladeshi migrants compared with white British residents and Bangladeshis still living in Bangladesh ('sedentees').MethodologyThe cross-sectional study compared serum vitamin D levels among 149 women aged 35-59, comprising British-Bangladeshi migrants (n = 50), white British neighbors (n = 54) and Bangladeshi sedentees (n = 45). Analyses comprised multivariate models to assess serum levels of 25-hydroxyvitamin D (25(OH)D), and associations with anthropometric, lifestyle, health and migration factors.ResultsVitamin D levels in Bangladeshi migrants were very low: mean 25(OH)D = 32.2 nmol/L ± 13.0, with 29% of migrants classified as deficient (<25 nmol/L) and 94% deficient or insufficient (≤50 nmol/L). Mean levels of vitamin D were significantly lower among British-Bangladeshis compared with Bangladeshi sedentees (50.9 nmol/L ± 13.3, P < 0.001) and were also lower than in white British women (55.3 nmol/L ± 20.9). Lower levels of vitamin D were associated with increased body mass index and low iron status.Conclusions and implicationsWe conclude that lower exposure to sunlight in the UK reduces vitamin D levels in Bangladeshi migrants. Recommending supplements could prevent potentially adverse health outcomes associated with vitamin D deficiency.Lay summaryVitamin D deficiency is one example of mismatch between an evolved trait and novel environments. Here we compare vitamin D status of dark-skinned British-Bangladeshi migrants in the UK to Bangladeshis in Bangladesh and white British individuals. Migrants had lower levels of vitamin D and are at risk for associated pathologies.

Project description:An increase in early-onset colorectal cancers (eoCRC), defined as a CRC before 50 years, is confirmed globally. CRC pathogenesis has been associated with several risk factors (family history, germline pathogenic variants, obesity, alcohol, physical activity, red meat, and a Western diet). Design: an international, multicenter, retrospective case-control study of prospectively enrolled patients; low-risk intervention study as it will perform a fecal occult blood test Endpoint: predictive power of a semi-quantitative food frequency questionnaire (SQFFQ) developed for eoCRC. Cases: Patients with a recent diagnosis of eoCRC (within 2 years from enrollment). Controls: matched by age (matching range ± 5 years) and sex. Healthy volunteers will be mainly enrolled among workers within the participating hospital center. The enrolled healthy volunteers will perform a fecal occult blood test. Variables of interest: age, sex, ethnicity, BMI at the time of eoCRC diagnosis and at 18 years old, country, tobacco smoking at the time of eoCRC diagnosis and at 18 years old, sitting time, TV-viewing time, moderate-to-vigorous physical activity (MVPA), waist circumference (cm), home blood pressure levels (mmHg), fasting blood glucose (mg/dl), regular consumption of aspirin/NSAID, calcium and folate supplements, oral contraceptive agents, post-menopausal hormones and years of consumptions, if the filled questionnaire reflects diet for the last 5-10 years before. Cases only: date of eoCRC diagnosis, symptoms at diagnosis, eoCRC localization, eoCRC stage, histological diagnosis, type of surgery, and date (if performed), chemotherapy and radiotherapy (if performed), vital status and duration of follow-up, family history of CRC and other cancers (uterus, ovary, stomach, small intestine, urinary tract/bladder/kidney, bile ducts, brain, pancreas, skin tumors), type of germline pathogenetic variant (if performed). Before the case-control study, three non-consecutive 24-hour Dietary Recalls (24hDRs) will validate the SQFFQ. The SQFFQ will be administered to the validation study group during three non-consecutive calls, including one non-weekday (30-minute 24-h-recall computer-aided personal interview). Primary Objective To measure the relative risk of specific dietary and lifestyle factors (smoking habit, alcohol intake, physical activity) for early-onset colorectal cancer in countries where eoCRC incidence is increasing versus stable/decreasing

Project description:We investigated the effects of PACAP treatment, and endogenous PACAP deficiency, on infarct volume, neurological function, and the cerebrocortical transcriptional response in a mouse model of stroke, middle cerebral artery occlusion (MCAO). PACAP-38 administered i.v. or i.c.v. 1 h after MCAO significantly reduced infarct volume, and ameliorated functional motor deficits measured 24 h later in wild-type mice. Infarct volumes and neurological deficits (walking faults) were both greater in PACAP-deficient than in wild-type mice, but treatment with PACAP reduced lesion volume and neurological deficits in PACAP-deficient mice to the same level of improvement as in wild-type mice. A 35,546-clone mouse cDNA microarray was used to investigate cortical transcriptional changes associated with cerebral ischemia in wild-type and PACAP-deficient mice, and with PACAP treatment after MCAO in wild-type mice. 229 known (named) transcripts were increased (228) or decreased (1) in abundance at least 50% following cerebral ischemia in wild-type mice. 49 transcripts were significantly up-regulated only at 1 h post-MCAO (acute response transcripts), 142 were up-regulated only at 24 h post-MCAO (delayed response transcripts) and 37 transcripts were up-regulated at both times (sustained response transcripts). More than half of these are transcripts not previously reported to be altered in ischemia. A larger percentage of genes up-regulated at 24 hr than at 1 hr required endogenous PACAP, suggesting a more prominent role for PACAP in later response to injury than in the initial response. This is consistent with a neuroprotective role for PACAP in late response to injury, i.e., even when administered 1 hr or more after MCAO. Putative injury effector transcripts regulated by PACAP include beta-actin, midline 2, and metallothionein 1. Potential neuroprotective transcripts include several demonstrated to be PACAP-regulated in other contexts. Prominent among these were transcripts encoding the PACAP-regulated gene Ier3, and the neuropeptides enkephalin, substance P (tachykinin 1), and neurotensin.

Dataset Information

Assessing Endogenous and Exogenous Hormone Exposures and Breast Development in a Migrant Study of Bangladeshi and British Girls.

Publications

Assessing Endogenous and Exogenous Hormone Exposures and Breast Development in a Migrant Study of Bangladeshi and British Girls.

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