The hair tales of women of color in Northern Manhattan: a qualitative analysis

Introduction

Exposure to endocrine disrupting chemicals (EDCs), such as phthalates, can negatively impact maternal and child health, contributing to impaired fetal growth, preterm birth, and pregnancy complications, as well as increased downstream risks of cardiometabolic disease and breast cancer. Notably, women of color (WOC) are the largest consumers of personal care products, which are a common source of EDC exposure.

Methods

The Let's Reclaim Our Ancestral Roots (Let's R.O.A.R) Pilot Study developed an educational intervention delivered during pregnancy to promote reduced use of phthalate-containing hair care products (HCPs). This mixed-methods study included: (1) a quantitative analysis and (2) a qualitative analysis of the educational sessions and the semi-structured focus groups to evaluate the factors that influenced the hair care practices and product choices of WOC at various stages of life, including their current pregnancy (hereafter referred to as the hair journey). During the sessions, participants learned about EDCs (with a focus on phthalates), the unequal burden of exposure for WOC, adverse implications of exposure, and exposure reduction strategies. Focus group sessions provided insight into participants' hair journeys from childhood to the current pregnancy and explored factors during their hair product selection process. All sessions were transcribed and imported into NVivo Version 12 for coding and thematic analysis.

Results

A total of 46 individuals were enrolled in the study, and 31 participated in an educational session. This current work synthesizes the qualitative analysis of this study. We identified two important life stages (before and after gaining agency over hair care practices and product choices) and three dominant themes related to HCP use: (1) products that impacted the hair journey, which involved all mentions of hair products, (2) factors that influenced the hair journey, which included individuals or entities that shaped participants' hair experiences, and (3) the relationship between hair and sense of self, where sense of self was defined as the alignment of one's inner and outer beauty.

Conclusion

The themes intersected and impacted the participants' hair journey. Cultural integration was a sub-theme that overlapped within the dominant themes and participants discussed the effect of traditions on their hair experiences.

Mixed-Method, Multilevel Clustered-Randomized Control Trial for Menstrual Health Disparities

Menstrual cycle characteristics are largely considered unmodifiable reproductive factors, a framing that prevents exploration of the ways structural factors interfere with menstrual health. Given the role of structural factors like healthy food and healthcare access on reproductive health and the grave need for structural interventions to known reproductive health disparities that disproportionately target cisgender women racialized as Black, it is imperative that science begin to examine how structural factors influence menstrual health. To explore such research, we employ critical race theory and intersectionality to illustrate what a structural intervention to improve menstrual cycle health could look like. Centering those with the greatest need, persons racialized as Black and/or LatinX living in food and healthcare deserts in Northern Manhattan, our illustrative sample includes four groups of persons who menstruate (e.g., cisgender girls and women) that are pre-menarche, pre-parous, postpartum, or perimenopausal. We describe a hypothetical, multilevel clustered-randomized control trial (cRCT) that provides psychoeducation on racism-related trauma and free delivered groceries to both treatment and control groups, while randomizing 30 clusters of housing associations to receive either sexual health clinics at their housing association or free vouchers for healthcare. We embed mixed methods (diaries, interviews, surveys, mobile apps, observation) into the design to evaluate the effectiveness of the 1-year intervention, in addition to determining the impact on participants through their perspectives. Through this illustration, we provide a novel example of how structural interventions can apply mixed methods to evaluate effectiveness while delivering services to populations impacted by multiple structural factors. We demonstrate how qualitative and quantitative approaches can be paired in clustered RCTs and how a living logic model can empirically incorporate the population perspective into more effective interventions. Lastly, we reveal how sensitive menstrual health is to structural factors and how upstream improvements will trickle down to potentially reduce health disparities in reproductive health.

Childhood physical activity and pubertal timing: findings from the LEGACY girls study

BACKGROUND

There is limited research on whether physical activity (PA) in early childhood is associated with the timing of pubertal events in girls.

METHODS

We used data collected over 2011-16 from the LEGACY Girls Study (n = 984; primarily aged 6-13 years at study enrolment), a multicentre North American cohort enriched for girls with a breast cancer family history (BCFH), to evaluate if PA is associated with age at thelarche, pubarche and menarche. Maternal-reported questionnaire data measured puberty outcomes, PA in early childhood (ages 3-5 years) and total metabolic equivalents of organized PA in middle childhood (ages 7-9 years). We used interval-censored Weibull parametric survival regression models with age as the time scale and adjusted for sociodemographic factors, and we tested for effect modification by BCFH. We used inverse odds weighting to test for mediation by body mass index-for-age z-score (BMIZ) measured at study enrolment.

RESULTS

Being highly active vs inactive in early childhood was associated with later thelarche in girls with a BCFH [adjusted hazard ratio (aHR) = 0.39, 95% CI = 0.26-0.59), but not in girls without a BCFH. In all girls, irrespective of BCFH, being in the highest vs lowest quartile of organized PA in middle childhood was associated with later menarche (aHR = 0.70, 95% CI = 0.50-0.97). These associations remained after accounting for potential mediation by BMIZ.

CONCLUSION

This study provides new data that PA in early childhood may be associated with later thelarche in girls with a BCFH, also further supporting an overall association between PA in middle childhood and later menarche.

Urinary Androgens Provide Additional Evidence Related to Metabolism and Are Correlated With Serum Androgens in Girls

Context

Androgen levels are generally measured in serum samples, but urine may be a more feasible option, especially in children, as it is a noninvasive alternative.

Objective

To assess the correlations of 10 urinary androgen metabolites with 4 serum androgens [dehydroepiandrosterone-sulfate (DHEA-S), androstenedione, and total and free testosterone] and assess if their correlations differ by participant characteristics.

Methods

Our study consisted of 44 girls, ages 6-13, who participated in the New York site of the LEGACY Girls Study and had both serum and urine samples collected at the same visit. We performed Pearson's correlation coefficient tests between 4 serum and 10 individual urinary metabolite measures and their sum. We examined the influence of participant characteristics on the magnitude and direction of the correlations.

Results

The summed urinary metabolite measures had the highest correlation with free testosterone in serum (global sum, r = 0.83) and correlated least with DHEA-S in serum (global sum, r = 0.64). The correlation between individual urinary metabolites and serum androgens ranged from 0.08 to 0.84.Two 11-oxygenated urinary metabolites (5α-androstane-3α-ol-11,17-dione5β-androstane-3α,11β-diol-17-one) were weakly correlated with all serum androgens. Participant age, weight, height, waist:hip ratio, and pubic hair growth stage changed the correlations between urinary and serum androgens measures between 10% and 213%.

Conclusion

The sum of urinary androgen metabolites was a good marker of circulating androstenedione, testosterone, and free testosterone. Individual urinary metabolites provide additional information about the metabolic processes of disease development compared to the antecedent serum androgens.

Immigrant generation status and its association with pubertal timing and tempo among Hispanic girls and boys

PURPOSE

In the United States, Hispanic-Latino children reach puberty earlier on average than non-Hispanic white children. Yet among U.S. Hispanic/Latino children, pubertal timing comparisons between immigrant generations have not been made, hence we examined whether pubertal timing differs by immigrant generational status, independent of BMI and acculturation measures.

METHODS

Cross-sectional data on 724 boys and 735 girls, aged 10-15 years, from the Hispanic Community Children's Health Study/Study of Latino (SOL) Youth, were used to predict the median ages of thelarche, pubarche, and menarche in girls, and pubarche and voice change in boys, using Weibull survival models, while adjusting for SOL center, BMI, and acculturation.

RESULTS

In girls, the first generation began thelarche earlier than second and third generations (median age [years] [95% confidence interval]: 7.4 [6.1, 8.8] vs. 8.5 [7.3, 9.7] and 9.1 [7.6, 10.7], respectively), but began menarche later (12.9 [12.0,137] vs. 11.8 [11.0, 12.5] and 11.6 [10.6, 12.6], respectively). Pubertal timing and tempo for boys did not differ by generational status.

CONCLUSIONS

First-generation U.S. Hispanic/Latino girls had the earliest thelarche, latest menarche and longest pubertal tempo, compared to second and third generations. Factors beyond BMI and acculturation may account for the differences in pubertal timing by generational status of U.S. Hispanic/Latino girls.

MANstruation: A cyberethnography of linguistic strategies of trans and nonbinary menstruators

Trans and nonbinary experiences of menstruation are subject to menstrual discourse that is deeply gendered. Terms such as "feminine hygiene" and "women's health" make trans and nonbinary people acutely aware that they fall outside of the ideal of the default menstruator. To better understand how such language affects menstruators who are not cis women and what alternative linguistic strategies they adopt, we conducted a cyberethnography of 24 YouTube videos created by trans and nonbinary menstruators, along with their 12,000-plus comments. We observed a range of menstrual experiences-dysphoria, tensions between femininity and masculinity, and transnormative pressures. Using grounded theory, we identified three distinct linguistic strategies vloggers adopted to navigate these experiences: (1) avoiding standard and feminizing language; (2) reframing language through masculinization; and (3) challenging transnormativity. The avoidance of standard and feminizing language, coupled with a reliance on vague and negative euphemisms, revealed feelings of dysphoria. Masculinizing strategies, on the other hand, navigated dysphoria through euphemisms-or even hyper-euphemisms-that showed an effort to reclaim menstruation to fit within the trans and nonbinary experience. Vloggers responded through tropes of hegemonic masculinity, using puns and wordplay, and sometimes relying on hypermasculinity and transnormativity. Transnormativity, however, can be polarizing, and vloggers and commenters who rejected stratification of trans and nonbinary menstruation challenged it. Taken together, these videos not only uncover an overlooked community of menstruators who demonstrate unique linguistic engagement with menstruation, but they also reveal destigmatization and inclusion strategies that can inform critical menstruation activism and research as a whole.

Why and How Epidemiologists Should Use Mixed Methods

The field of epidemiology's current focus on causal inference follows a quantitative approach and limits research questions to those that are strictly quantifiable. How can epidemiologists study biosociocultural public health problems that they cannot easily quantify? The mixed-methods approach offers a possible solution by incorporating qualitative sociocultural factors as well as the perspective and context from the population under study into quantitative studies. After a pluralist perspective of causal inference, this article provides a guide for epidemiologists interested in applying mixed methods to their observational studies of causal identification and explanation. We begin by reviewing the current paradigms guiding quantitative, qualitative, and mixed methodologies. We then describe applications of convergent and sequential mixed-methods designs to epidemiologic concepts including confounding, mediation, effect modification, measurement, and selection bias. We provide concrete examples of how epidemiologists can use mixed methods to answer research questions of complex bio-socio-cultural health outcomes. We also include a case study of using mixed methods in an observational study design. We describe how mixed methods can enhance how epidemiologists define underlying causal structures. Our alignment of mixed-methods study designs with epidemiologic concepts addresses a major gap in current epidemiology education- how do epidemiologists systematically determine what goes into causal structures?

Maternal and prenatal factors and age at thelarche in the LEGACY Girls Study cohort: implications for breast cancer risk

BACKGROUND

Earlier onset of breast development (thelarche) is associated with increased breast cancer risk. Identifying modifiable factors associated with earlier thelarche may provide an opportunity for breast cancer risk reduction starting early in life, which could especially benefit girls with a greater absolute risk of breast cancer due to family history.

METHODS

We assessed associations of maternal pre-pregnancy body mass index (BMI), physical activity during pregnancy, gestational weight gain and daughters' weight and length at birth with age at thelarche using longitudinal Weibull models in 1031 girls in the Lessons in Epidemiology and Genetics of Adult Cancer from Youth (LEGACY) Girls Study-a prospective cohort of girls, half of whom have a breast cancer family history (BCFH).

RESULTS

Girls whose mothers had a pre-pregnancy BMI of ≥25 and gained ≥30 lbs were 57% more likely to experience earlier thelarche than girls whose mothers had a pre-pregnancy BMI of <25 and gained <30 lbs [hazard ratio (HR) = 1.57, 95% CI: 1.16, 2.12]. This association was not mediated by childhood BMI and was similar in girls with and without a BCFH (BCFH: HR = 1.41, 95% CI: 0.87, 2.27; No BCFH: HR = 1.62, 95% CI: 1.10, 2.40). Daughters of women who reported no recreational physical activity during pregnancy were more likely to experience earlier thelarche compared with daughters of physically active women. Birthweight and birth length were not associated with thelarche.

CONCLUSION

Earlier thelarche, a breast cancer risk factor, was associated with three potentially modifiable maternal risk factors-pre-pregnancy BMI, gestational weight gain and physical inactivity-in a cohort of girls enriched for BCFH.

Body mass index rebound and pubertal timing in girls with and without a family history of breast cancer: the LEGACY girls study

BACKGROUND

Heavier body mass index (BMI) is the most established predictor of earlier age at puberty. However, it is unknown whether the timing of the childhood switch to heavier BMI (age at BMI rebound) also matters for puberty.

METHODS

In the LEGACY Girls Study (n = 1040), a longitudinal cohort enriched with girls with a family history of breast cancer, we collected paediatric growth chart data from 852 girls and assessed pubertal development every 6 months. Using constrained splines, we interpolated individual growth curves and then predicted BMI at ages 2, 4, 6, 8 and 9 years for 591 girls. We defined age at BMI rebound as the age at the lowest BMI between ages 2 and 8 years and assessed its association with onset of thelarche, pubarche and menarche using Weibull survival models.

RESULTS

The median age at BMI rebound was 5.3 years (interquartile range: 3.6-6.7 years). A 1-year increase in age at BMI rebound was associated with delayed thelarche (HR = 0.90; 95% CI = 0.83-0.97) and menarche (HR = 0.86; 95% CI = 0.79-0.94). The magnitude of these associations remained after adjusting for weight between birth and 2 years, was stronger after adjusting for BMI at age 9, and was stronger in a subset of girls with clinically assessed breast development.

CONCLUSIONS

Earlier BMI rebound is associated with earlier pubertal timing. Our observation that BMI rebound may be a driver of pubertal timing in girls with and without a family history of breast cancer provides insight into how growth and pubertal timing are associated with breast cancer risk.

"Mother's Health and Well-Being Matters: Is a Mediated Social Cohesion Public Health Intervention Feasible?"

PURPOSE

To test the feasibility of introducing 'Free Time for Wellness' (FT4W) an intervention to increase healthy behaviours and reduce the risk of cancer.

DESIGN

Feasibility study; Setting: Washington Heights, New York, USA is a low socioeconomic status area.

SUBJECTS

Mothers aged 18 and above with children under 12 years of age and living in Washington Heights were recruited.

INTERVENTION

FT4W, a community-based intervention delivered through a neighbourhood-based app, offering weekly dance and yoga classes, food pantry visits and group playdates. Childcare professionals cared for participants' children during wellness activities.

MEASURES

A bespoke before and after survey was designed and tested for its ability to collect relevant data to assess the impact of FT4W. Outcomes included recruitment rates, participation, attrition, acceptability, and success of the community champion.

ANALYSIS

Comparisons of proportions and means.

RESULTS

Twenty-one mothers participated in the study of which 90% attended ≥ 1 FT4W activity; 65% ≥ 2; 52% ≥ 3. The survey was completed by a 100% of participants indicating it was easy to understand and not too burdensome. All measures detected change in constructs from baseline to follow-up. Availability of childcare was the most commonly (66%) reported reason participants were able to engage in the offered wellness activities.

CONCLUSION

Conducting a larger-scale trial to assess the impact of FT4W is feasible considering 4 major lessons. (1) Recruitment, retention, and acceptability rates were high; however, moms need additional support to increase participation in wellness activities and improve tech literacy. (2) Research measures were sensitive enough to detect change, but the timing of assessments needs to be considered. (3) Participants greatly valued access to professional childcare. (4) The Community Champion is a necessary, but difficult role to fill that requires careful consideration by the Institutional Review Board (IRB).

Free Time For Wellness: a co-designed intervention utilizing social networks to encourage physical activity for cancer prevention among low resourced mothers

BACKGROUND

Physical activity is central to chronic disease prevention. Low resource mothers face structural barriers preventing them from increasing their physical activity to reduce their chronic disease risk. We co-designed an intervention, with the ultimate goal of building social cohesion through social media to increase physical activity for low resourced mothers in urban settings.

METHODS

In 2019, we interviewed 10 mothers of children (< 12 years) living in Washington Heights, Manhattan. The interviews were transcribed and coded for themes that guided the creation of a co-design workshop. Washington Heights-based mothers (n = 16) attended a co-design workshop to generate the blueprint for the Free Time for Wellness intervention.

RESULTS

Mothers in our sample had limited time, external support and resources, which hindered them from increasing their physical activity; we learned that in addition to physical health, mental health was a concern for participants. Participants had varying degrees of self-efficacy and trust in social media. Bringing mothers and researchers together in a co-design workshop, we identified types of physical activities they would enjoy participating in, the ideal time to do so, the kind of childcare they needed, and their preferences for communication with the community champion. The interviews and workshop highlighted the need for a community space that mothers and children could co-occupy. The intervention was designed to be 3 months' worth of sample programming with one activity per week, rotating between dance, yoga, food pantry visits and group playdates. Participants were invited to bring their children to a space with one room for the 'participants only' activity and a second room in which professional childcare providers supervised the children.

CONCLUSIONS

Through this two-phased co-design process, we created an intervention with mothers in an urban community with the goal of using social media to bring them together for wellness, primarily through increased physical activity. Despite the co-design of this intervention with a specific community, there are some universal applications of our findings, and of the use of co-design workshops, to other settings.

Use of Social Media for Cancer Prevention Through Neighborhood Social Cohesion: Protocol for a Feasibility Study

Background

Social cohesion is associated with healthier behaviors and better health outcomes, and therefore may offer a mechanism for promoting better health. Low socioeconomic status (SES) communities face higher rates of chronic disease due to both community- and individual-level factors.

Objective

The aim of this study is to leverage social cohesion to promote healthier behaviors and prevent chronic disease in a low SES community. This protocol outlines the methodology for a pilot study to assess the feasibility of an intervention (Free Time For Wellness [FT4W]) using a social networking platform (Nextdoor) with mothers living in an urban, low-income community to improve social cohesion and promote healthy behaviors.

Methods

The study will involve three phases: (I) co-designing the intervention with mothers in the neighborhoods of interest, (II) implementing the intervention with community leaders through the social networking platform, and (III) evaluating the intervention’s feasibility. Phase I of the study will include qualitative data collection and analysis from in-depth, semistructured interviews and a co-design group session with mothers. Phases II and III of the study include a pre- and postintervention survey of participating mothers. Neighborhood-level data on social cohesion will also be collected to enable comparison of outcomes between neighborhoods with higher and lower baseline social cohesion.

Results

As of March 2021, recruitment and data collection for this study are complete. This protocol outlines our original study plan, although the final enrollment numbers and intervention implementation deviated from our initial planned methodology that is outlined in this protocol. These implementation learnings will be shared in subsequent publications of our study results.

Conclusions

Ultimately, this study aims to: (1) determine the barriers and facilitators to finding free time for wellness among a population of low-income mothers to inform the co-design process, and (2) implement and study the feasibility of an intervention that leverages social cohesion to promote physical activity in a community of low-income mothers. The results of this study will provide preliminary feasibility evidence to inform a larger effectiveness trial, and will further our understanding of how social cohesion might influence well-being.

International Registered Report Identifier (IRRID)

RR1-10.2196/28147

Prepubertal Internalizing Symptoms and Timing of Puberty Onset in Girls

Stressful environments have been associated with earlier menarche. We hypothesized that anxiety, and possibly other internalizing symptoms, are also associated with earlier puberty in girls. The Lessons in Epidemiology and Genetics of Adult Cancer From Youth (LEGACY) Girls Study (2011-2016) included 1,040 girls aged 6-13 years at recruitment whose growth and development were assessed every 6 months. Prepubertal maternal reports of daughter's internalizing symptoms were available for breast onset (n = 447), pubic hair onset (n = 456), and menarche (n = 681). Using Cox proportional hazard regression, we estimated prospective hazard ratios and 95% confidence intervals for the relationship between 1 standard deviation of the percentiles of prepubertal anxiety, depression, and somatization symptoms and the timing of each pubertal outcome. Multivariable models included age, race/ethnicity, study center, maternal education, body mass index percentile, and family history of breast cancer. Additional models included maternal self-reported anxiety. A 1-standard deviation increase in maternally reported anxiety in girls at baseline was associated with earlier subsequent onset of breast (hazard ratio (HR) = 1.22, 95% confidence interval (CI): 1.09, 1.36) and pubic hair (HR = 1.15, 95% CI: 1.01, 1.30) development, but not menarche (HR = 0.94, 95% CI: 0.83, 1.07). The association of anxiety with earlier breast development persisted after adjustment for maternal anxiety. Increased anxiety in young girls may indicate risk for earlier pubertal onset.

The Politics, Promises, and Perils of Data: Evidence-Driven Policy and Practice for Menstrual Health

Data determine what we know about the menstrual cycle; they inform policy and program decisions; they can point us to neglected issues and populations. But collecting and analyzing data are complicated and often fraught processes, because data are political and subjective, decisions on what data we collect and what data we do not collect are not determined by accident. As a result, despite the significant potential of the current rise in attention to menstruation, we also see risks: a lack of a solid evidence base for program decisions and resulting sensationalization; concerns about data privacy; an overreliance on participants' recall, on the one hand, while not involving participants adequately in decision making, on the other hand; and a lack of contextualized and disaggregated data. Yet better communication, contextualization, and collaboration can address many of these risks.

The Steroid Metabolome and Breast Cancer Risk in Women with a Family History of Breast Cancer: The Novel Role of Adrenal Androgens and Glucocorticoids

BACKGROUND

No study has comprehensively examined how the steroid metabolome is associated with breast cancer risk in women with familial risk.

METHODS

We examined 36 steroid metabolites across the spectrum of familial risk (5-year risk ranged from 0.14% to 23.8%) in pre- and postmenopausal women participating in the New York site of the Breast Cancer Family Registry (BCFR). We conducted a nested case-control study with 62 cases/124 controls individually matched on menopausal status, age, and race. We measured metabolites using GC-MS in urine samples collected at baseline before the onset of prospectively ascertained cases. We used conditional logistic regression to estimate odds ratios (OR) and 95% confidence intervals (CI) per doubling in hormone levels.

RESULTS

The average proportion of total steroid metabolites in the study sample were glucocorticoids (61%), androgens (26%), progestogens (11%), and estrogens (2%). A doubling in glucocorticoids (aOR = 2.7; 95% CI = 1.3-5.3) and androgens (aOR = 1.6; 95% CI = 1.0-2.7) was associated with increased breast cancer risk. Specific glucocorticoids (THE, THF αTHF, 6β-OH-F, THA, and α-THB) were associated with 49% to 161% increased risk. Two androgen metabolites (AN and 11-OH-AN) were associated with 70% (aOR = 1.7; 95% CI = 1.1-2.7) and 90% (aOR = 1.9; 95% CI = 1.2-3.1) increased risk, respectively. One intermediate metabolite of a cortisol precursor (THS) was associated with 65% (OR = 1.65; 95% CI = 1.0-2.7) increased risk. E1 and E2 estrogens were associated with 20% and 27% decreased risk, respectively.

CONCLUSIONS

Results suggest that glucocorticoids and 11-oxygenated androgens are positively associated with breast cancer risk across the familial risk spectrum.

IMPACT

If replicated, our findings suggest great potential of including steroids into existing breast cancer risk assessment tools.

The timing of adrenarche in Maya girls, Merida, Mexico

Background

Adrenarche involves maturation of the hypothalamic‐pituitary‐adrenal axis and increased production of dehydroepiandrosterone and its sulfate ester, dehydroepiandrosterone‐sulfate (DHEA‐S). It occurs at ages 6 to 8 in industrialized populations, marking the transition from childhood to juvenility and cognitive development at middle childhood. Studies in subsistence level populations indicate a later age (8‐9) for adrenarche, but only two such studies currently exist for comparison.

Aims

To investigate adrenarcheal age among Maya girls and its association with body composition and dietary variables. We hypothesized adrenarche would occur earlier given the current dual burden of nutrition in Mexico.

Materials and Methods

25 Maya girls aged 7 to 9 from Merida, Mexico using ELISAs to measure salivary DHEA‐S, standard anthropometry for height, weight, and skinfolds, bioelectrical impedance for body composition variables, as well as a food frequency questionnaire for dietary information.

Results

Our hypothesis was rejected—adrenarche occurred close to 9 years. While no measures of body composition were significantly associated with adrenarcheal status, girls eating meat and dairy products more frequently had significantly higher DHEA‐S levels.

Discussion

Like other populations living in ecologically challenging environments, adrenarche occurred relatively late among Maya girls. Adrenarche has been linked to measures of body composition, particularly, the adiposity or body mass index rebound, but no relevant anthropometric measures were associated, possibly because of the small sample.

Conclusion

Further studies are required to illuminate how adrenarcheal variation relates to developmental plasticity, body composition, pubertal progression, and animal product consumption in other transitional populations.

Risk of Prostate Cancer-related Death Following a Low PSA Level in the PLCO Trial

Longer-than-annual screening intervals have been suggested to improve the balance of benefits and harms in prostate cancer screening. Many researchers, societies, and guideline committees have suggested that screening intervals could depend on the prostate-specific antigen (PSA) result. We analyzed data from men (N = 33,897) ages 55-74 years with a baseline PSA test in the intervention arm of the Prostate, Lung, Colorectal and Ovarian Cancer Screening trial (United States, 1993-2001). We estimated 5- and 10-year risks of aggressive cancer (Gleason ≥8 and/or stage III/IV) and 15-year risks of prostate cancer-related mortality for men with baseline PSA ≤ 0.5 ng/mL (N = 4,862), ≤1 ng/mL (N = 15,110), and 1.01-2.5 ng/mL (N = 12,422). A total of 217 men died from prostate cancer through 15 years, although no men with PSA ≤ 1 ng/mL died from prostate cancer within 5 years [95% confidence interval (CI), 0.00%-0.03%]. The 5-year incidence of aggressive disease was low (0.08%; 95% CI, 0.03%-0.12%) for men with PSA ≤ 1 ng/mL, and higher for men with baseline PSA 1.01-2.5 ng/mL (0.51%; 95% CI, 0.38%-0.74%). No men aged ≥65 years with PSA ≤ 0.5 ng/mL died from prostate cancer within 15 years (95% CI, 0.00%-0.32%), and their 10-year incidence of aggressive disease was low (0.25%; 95% CI, 0.00%-0.53%). Compared with white men, black men with PSA ≤ 1 ng/mL had higher 10-year rates of aggressive disease (1.6% vs. 0.4%; P < 0.01). Five-year screening intervals may be appropriate for the 45% of men with PSA ≤ 1 ng/mL. Men ages ≥65 years with PSA ≤ 0.5 ng/mL could consider stopping screening. Substantial risk disparities suggest appropriate screening intervals could depend on race/ethnicity.

Mobilizing Breast Cancer Prevention Research Through Smartphone Apps: A Systematic Review of the Literature

Background: Breast cancer rates have been increasing worldwide, particularly among young women, suggesting important interactions between genes and health behaviors. At the same time, mobile technology, including smartphones applications (apps), has emerged as a new tool for delivering healthcare and health-related services. As of 2018, there were nearly 600 publicly available breast cancer apps designed to provide disease and treatment information, to manage disease, and to raise overall awareness. However, the extent to which apps are incorporated into breast cancer prevention research is unknown. Therefore, the objective of this review was to determine how mobile applications are being used for breast cancer prevention among women across the cancer control continuum. Methods: Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we searched PubMed and Web of Science Core Collection databases using the keywords breast cancer, smartphone, mobile application, and phone app. Full-length journal articles available in English that addressed the research question were included. We categorized articles by prevention type (primary, secondary, and tertiary) and phase of research (protocol, development, feasibility, pilot, measurement, and effectiveness), and identified common themes and gaps. Results: Our search yielded 82 studies (69 unique) that used apps in breast cancer prevention research across 20 countries. Approximately half of the named apps were publicly available. The majority (73%) of studies targeted tertiary prevention; 15% targeted secondary and 13% targeted primary prevention. Apps were used across all phases of research with the predominant phase being feasibility in tertiary prevention (34%), effectiveness in secondary prevention (63%), and development (30%) and effectiveness (30%) in primary prevention. Common uses included assessing outcomes relevant to clinical care coordination, quality of life, increasing self-efficacy and screening behaviors, and tracking and managing health behaviors. Conclusions: We identified the following gaps: few effectiveness studies in tertiary prevention, minimal use of apps for breast cancer etiology or early detection, and few interventions in those at average risk of breast cancer. These findings suggest that while mobile apps can inform breast cancer prevention across the continuum, more work is needed to incorporate apps into primary prevention.

Early-Life Growth and Benign Breast Disease

Using prospective data from the Early Determinants of Mammographic Density study (United States, 1959-2008, n = 1121), we examined the associations between maternal body size, birth size, and infant and early childhood growth during 3 time periods (0-4 months, 4-12 months, and 1-4 years) and benign breast disease (BBD) using multivariable logistic regression with generalized estimating equations. A total of 197 women (17.6%) reported receiving a diagnosis of BBD by a physician. Higher body mass index at age 7 years was inversely associated with BBD risk. Rapid weight gain from age 1 year to 4 years, defined as an increase of least 2 major percentiles (e.g., 5th, 10th, 25th, 50th, 75th, and 95th) relative to stable growth, defined as remaining within 2 percentiles, was also inversely associated with BBD (odds ratio (OR) = 0.51, 95% confidence interval (CI): 0.23, 1.15). In contrast, rapid weight gain in infancy was positively associated with BBD relative to stable growth (from 0 to 4 months, OR = 1.65, 95% CI: 1.04, 2.62; from 4 to 12 months, 1.85, 95% CI: 0.89, 3.85), independent of birth weight, which was not associated with BBD. Our results suggest that patterns of early-life weight gain are important to BBD risk. Thus, susceptibility to BBD, like susceptibility to breast cancer, might start in early life.

Do Birth Weight and Weight Gain During Infancy and Early Childhood Explain Variation in Mammographic Density in Women in Midlife? Results From Cohort and Sibling Analyses

High birth weight is associated with increased breast cancer risk and, less consistently, with higher mammographic density. In contrast, adolescent body size has been consistently, negatively associated with both MD and breast cancer risk. It is unclear when the direction of these associations changes and whether weight gain in infancy is associated with MD. We evaluated the associations of birth weight and postnatal weight (measured at 4 months, 1 year, and 4 years) by absolute and velocity measures (relative within-cohort percentile changes) with adult mammographic density, assessed using a computer-assisted thresholding program (Cumulus), using linear regression models with generalized estimating equations to account for correlation between siblings in the Early Determinants of Mammographic Density study (1959-2008; n = 700 women with 116 sibling sets; mean age = 44.1 years). Birth weight was positively associated with dense area (per 1-kg increase, β = 3.36, 95% confidence interval (CI): 0.06, 6.66). Weight gains from 0 months to 4 months and 1 year to 4 years were negatively associated with dense area (for 10-unit increase in weight percentile, β = -0.65, 95% CI: -1.23, -0.07, and β = -1.07, 95% CI: -1.98, -0.16, respectively). Findings were similar in the sibling subset. These results support the hypothesis that high birth weight is positively associated with increased breast density and suggest that growth spurts starting in early infancy reduce mammographic dense area in adulthood.

Association of Prepubertal and Adolescent Androgen Concentrations With Timing of Breast Development and Family History of Breast Cancer

IMPORTANCE

Early breast development is a risk factor for breast cancer, and girls with a breast cancer family history (BCFH) experience breast development earlier than girls without a BCFH.

OBJECTIVES

To assess whether prepubertal androgen concentrations are associated with timing of breast development (analysis 1) and to compare serum androgen concentrations in girls with and without a BCFH (analysis 2).

DESIGN, SETTING, AND PARTICIPANTS

Prospective cohort study of 104 girls aged 6 to 13 years at baseline using data collected between August 16, 2011, and March 24, 2016, from the Lessons in Epidemiology and Genetics of Adult Cancer From Youth (LEGACY) Girls Study, New York site.

EXPOSURES

Analysis 1 included serum concentrations of dehydroepiandrosterone sulfate, androstenedione, and testosterone (free and total) measured before breast development and divided at the median into high and low categories. Analysis 2 included the degree of BCFH: first-degree was defined as having a mother with breast cancer and second-degree was defined as having a grandmother or aunt with breast cancer.

MAIN OUTCOMES AND MEASURES

Analysis 1 included age at onset of breast development measured using the Pubertal Development Scale (scores range from 1-4; scores ≥2 indicate breast development), and analysis 2 included serum androgen concentrations. We also assessed breast cancer-specific distress using the 8-item Child Impact of Events Scale.

RESULTS

Our analyses included 36 girls for the prospective model, 92 girls for the cross-sectional model, and 104 girls for the longitudinal model. Of the 104 girls, the mean (SD) age at baseline was 10.3 (2.5) years, and 41 (39.4%) were non-Hispanic white, 41 (39.4%) were Hispanic, 13 (12.5%) were non-Hispanic black, and 9 (8.7%) were other race/ethnicity. Forty-two girls (40.4%) had a positive BCFH. Girls with prepubertal androstenedione concentrations above the median began breast development 1.5 years earlier than girls with concentrations below the median (Weibull survival model-estimated median age, 9.4 [95% CI, 9.0-9.8] years vs 10.9 [95% CI, 10.4-11.5] years; P = .001). Similar patterns were observed for dehydroepiandrosterone sulfate (1.1 years earlier: age, 9.6 [95% CI, 9.1-10.1] years vs 10.7 [95% CI, 10.2-11.3] years; P = .009), total testosterone (1.4 years earlier: age, 9.5 [95% CI, 9.1-9.9] years vs 10.9 [95% CI, 10.4-11.5] years; P = .001), and free testosterone (1.1 years earlier: age, 9.7 [95% CI, 9.2-10.1] years vs 10.8 [95% CI, 10.2-11.4] years; P = .01). Compared with girls without BCFH, girls with a first-degree BCFH, but not a second-degree BCFH, had 240% higher androstenedione concentrations (geometric means: no BCFH, 0.49 ng/mL vs first-degree BCFH, 1.8 ng/mL vs second-degree, 1.6 ng/mL; P = .01), 10% higher total testosterone concentrations (12.7 ng/dL vs 14.0 ng/dL vs 13.7 ng/dL; P = .01), and 92% higher free testosterone concentrations (1.3 pg/mL vs 2.5 pg/mL vs 0.3 pg/mL; P = .14). The dehydroepiandrosterone sulfate concentration did not differ between BCFH-positive and BCFH-negative girls but was elevated in girls with breast cancer-specific distress.

CONCLUSIONS AND RELEVANCE

Our findings suggest that androgen concentrations may differ between girls with and without a BCFH and that elevated hormone concentrations during adolescence may be another factor to help explain the familial clustering of breast cancer.

Estrogen Metabolism in Premenopausal Women Is Related to Early Life Body Fatness

Background: Estrogen metabolism in premenopausal women may be related to early life body fatness.Methods: Premenopausal women participating in the Nurses' Health Study II recalled their body fatness at ages 5, 10, and 20 years using a validated 9-level pictogram. Fifteen estrogens and estrogen metabolites (EM) were measured using LC/MS-MS in luteal phase urines from 603 women ages 32-54 years. Geometric means of individual EM, metabolic pathway groups, and pathway ratios were examined by body fatness categories using linear mixed models.Results: Body fatness at each age was inversely associated with adult concentrations of all EM combined, parent estrogens (estrone, estradiol), and the 2-hydroxylation pathway. Women in the top (vs. bottom) category of body fatness at age 10 had 21% lower levels of all EM (Ptrend = 0.003), 24% lower parent estrogens (Ptrend = 0.002), and 36% lower 2-pathway (Ptrend = 0.0003). Body fatness at age 10 was inversely associated with 2-catechols (35% lower, Ptrend = 0.0004) and 2-methylated catechols (30% lower, Ptrend = 0.002). After adjusting for premenopausal body mass index (BMI), these associations remained inverse but were attenuated; only parent estrogens remained statistically significant (21% lower, Ptrend = 0.01). Body fatness at ages 5 and 20 were similarly, but more weakly, associated with estrogen pathways.Conclusions: Estimates of body fatness during early life were inversely associated with premenopausal levels of all EM combined, parent estrogens, and 2-pathway estrogen metabolites. These relationships were not fully explained by adult BMI.Impact: These findings inform investigations of diseases linked to early life body fatness and estrogen metabolism. Cancer Epidemiol Biomarkers Prev; 27(5); 585-93. ©2018 AACR.

Comparison of methods to assess onset of breast development in the LEGACY Girls Study: methodological considerations for studies of breast cancer

Background

Younger age at onset of breast development, which has been declining in recent decades, is associated with increased breast cancer risk independent of age at menarche. Given the need to study the drivers of these trends, it is essential to validate methods to assess breast onset that can be used in large-scale studies when direct clinical assessment of breast onset is not feasible.

Methods

Breast development is usually measured by Tanner stages (TSs), assessed either by physical examination or by mother’s report using a picture-based Sexual Maturation Scale (SMS). As an alternative, a mother-reported Pubertal Development Scale (PDS) without pictures has been used in some studies. We compared agreement of SMS and PDS with each other (n = 1022) and the accuracy of PDS with clinical TS as a gold standard for the subset of girls with this measure (n = 282) using the LEGACY cohort. We further compared prediction of breast onset using ROC curves and tested whether adding urinary estrone 1-glucuronide (E1G) improved the AUC.

Results

The agreement of PDS with SMS was high (kappa = 0.80). The sensitivity of PDS vs clinical TS was 86.6%. The AUCs for PDS alone and SMS alone were 0.88 and 0.79, respectively. Including E1G concentrations improved the AUC for both methods (0.91 and 0.86 for PDS and SMS, respectively).

Conclusions

The PDS without pictures is a highly accurate, sensitive, and specific method for assessing breast onset, especially in settings where clinical TS is not feasible. In addition, it is comparable to SMS methods with pictures and thus easier to implement in large-scale studies, particularly phone-based interviews where pictures may not be available. Urinary E1G can improve accuracy over than PDS or SMS alone.

Electronic supplementary material

The online version of this article (10.1186/s13058-018-0943-9) contains supplementary material, which is available to authorized users.

Why do studies show different associations between intrauterine exposure to maternal smoking and age at menarche?

PURPOSE

Studies suggests that intrauterine exposure to maternal smoking both accelerates or delays age at menarche. We hypothesize that these opposing findings relate to different infant and childhood growth patterns across cohorts.

METHODS

Using data from an adult follow-up study of the Child Health and Development Studies and the National Collaborative Perinatal Project, we examined, using generalized estimating linear regression models, whether intrauterine exposure to maternal smoking was associated with age at menarche in 1090 daughters before and after accounting for growth in weight.

RESULTS

Compared to the nonexposed, intrauterine exposure to maternal smoking was associated with a 4-month acceleration in menarche in the National Collaborative Perinatal Project (β = -0.35 years; 95% confidence interval [CI]: -0.63, -0.08), but a 6-month delay in menarche in the Child Health and Development Studies (β = 0.48 years; 95% CI: 0.13, 0.83), despite having a similar reduction in birth weight in both cohorts (∼300 g). The results were more consistent across cohorts when we stratified by postnatal growth patterns. For example, in those with rapid weight gain (increasing two growth references from 0 to 4 years), intrauterine exposure to maternal smoking was related to a 7-month acceleration in menarche (β = -0.56 years; 95% CI: -0.95, -0.17).

CONCLUSIONS

These findings suggest that the association of intrauterine exposure to maternal smoking on age at menarche depends on postnatal growth patterns.

Pubertal development in girls by breast cancer family history: the LEGACY girls cohort

Background

Pubertal milestones, such as onset of breast development and menstruation, play an important role in breast cancer etiology. It is unclear if these milestones are different in girls with a first- or second-degree breast cancer family history (BCFH).

Methods

In the LEGACY Girls Study (n = 1040), we examined whether three mother/guardian-reported pubertal milestones (having reached Tanner Stage 2 or higher (T2+) for breast and pubic hair development, and having started menstruation) differed by BCFH. We also examined whether associations between body size and race/ethnicity and pubertal milestones were modified by BCFH. We used mother/guardian reports as the primary measure of pubertal milestones, but also conducted sensitivity analyses using clinical Tanner measurements available for a subcohort (n = 204). We analyzed cross-sectional baseline data with logistic regression models for the entire cohort, and longitudinal data with Weibull survival models for the subcohort of girls that were aged 5–7 years at baseline (n = 258).

Results

BCFH was modestly, but not statistically significantly, associated with Breast T2+ (odds ratio (OR) = 1.36, 95% confidence interval (CI) = 0.88–2.10), with a stronger association seen in the subcohort of girls with clinical breast Tanner staging (OR = 2.20, 95% CI = 0.91–5.32). In a longitudinal analysis of girls who were aged 5–7 years at baseline, BCFH was associated with a 50% increased rate of having early breast development (hazard ratio (HR) = 1.49, 95% CI = 1.0–2.21). This association increased to twofold in girls who were not overweight at baseline (HR = 2.04, 95% CI = 1.29–3.21). BCFH was not associated with pubic hair development and post-menarche status. The median interval between onset of breast development and menarche was longer for BCFH+ than BCFH– girls (2.3 versus 1.7 years), suggesting a slower developmental tempo for BCFH+ girls. Associations between pubertal milestones and body size and race/ethnicity were similar in girls with or without a BCFH. For example, weight was positively associated with Breast T2+ in both girls with (OR = 1.06 per 1 kg, 95% CI = 1.03–1.10) and without (OR = 1.14 per 1 kg, 95% CI = 1.04–1.24) a BCFH.

Conclusions

These results suggest that BCFH may be related to earlier breast development and slower pubertal tempo independent of body size and race/ethnicity.

Electronic supplementary material

The online version of this article (doi:10.1186/s13058-017-0849-y) contains supplementary material, which is available to authorized users.

Maternal and Early Childhood Determinants of Women's Body Size in Midlife: Overall Cohort and Sibling Analyses

Observational evidence suggests that adult body size has its roots earlier in life, yet few life-course studies have data on siblings with which to control for family-level confounding. Using prospective data from the Early Determinants of Mammographic Density Study (n = 1,108; 1959-2008), we examined the association of maternal prepregnancy body mass index (BMI; weight (kg)/height (m)2), gestational weight gain (GWG), birth size, and childhood growth factors with adult BMI in daughters at midlife using quantile, linear, and logistic regression models. We compared overall cohort findings (n = 1,108) with sibling differences (n = 246 sibling sets). Results derived by all 3 regression methods supported positive and independent associations of prepregnancy BMI, GWG, and percentile change in early childhood growth with BMI in daughters at midlife. Sibling analyses demonstrated that higher GWG was independently related to a higher adult BMI in daughters, particularly for the highest 90th quantile of adult BMI (β = 0.64 (standard error, 0.26) BMI units). Greater increases in weight percentiles between 1 and 4 years of age within siblings were also associated with higher adult BMI in the 75th quantile (β = 0.06 (standard error, 0.03) kg). Thus, even after consideration of the role of family-level fixed effects, maternal GWG and childhood weight gain are associated with adult body size in midlife.

Potential Intervention Targets in Utero and Early Life for Prevention of Hormone Related Cancers

Hormone-related cancers have long been thought to be sensitive to exposures during key periods of sexual development, as shown by the vulnerability to such cancers of women exposed to diethylstilbestrol in utero. In addition to evidence from human studies, animal studies using new techniques, such as gene knockout models, suggest that an increasing number of cancers may be hormonally related, including liver, lung, and bladder cancer. Greater understanding of sexual development has also revealed the "mini-puberty" of early infancy as a key period when some sex hormones reach levels similar to those at puberty. Factors driving sex hormones in utero and early infancy have not been systematically identified as potential targets of intervention for cancer prevention. On the basis of sex hormone pathways, we identify common potentially modifiable drivers of sex hormones, including but not limited to factors such as obesity, alcohol, and possibly nitric oxide. We review the evidence for effects of modifiable drivers of sex hormones during the prenatal period and early infancy, including measured hormones as well as proxies, such as the second-to-fourth digit length ratio. We summarize the gaps in the evidence needed to identify new potential targets of early life intervention for lifelong cancer prevention.

Associations of Breast Cancer Risk Factors with Premenopausal Sex Hormones in Women with Very Low Breast Cancer Risk

Breast cancer incidence rates are low but rising in urban Mongolia. We collected reproductive and lifestyle factor information and measured anthropometrics and serum sex steroid concentrations among 314 premenopausal women living in Ulaanbaatar, Mongolia. Mean differences in hormone concentrations by these factors were calculated using age-adjusted quadratic regression splines. Estrone and estradiol in college-educated women were, respectively, 18.2% (p = 0.03) and 23.6% (p = 0.03) lower than in high-school-educated women. Progesterone concentrations appeared 55.8% lower (p = 0.10) in women residing in modern housing compared with women living in traditional housing (gers), although this finding was not statistically significant. Testosterone concentrations were positively associated with adiposity and central fat distribution; 17.1% difference (p = 0.001) for highest vs. lowest quarter for body mass index and 15.1% difference (p = 0.005) for waist-to-height ratio. Estrogens were higher in the follicular phase of women who breastfed each child for shorter durations. A distinct hormonal profile was associated with an urban lifestyle in premenopausal, Mongol women. In particular, heavier, more-educated women living in urban dwellings had higher testosterone and lower estrogen and progesterone levels. Higher breast cancer incidence in urban compared with rural women suggest that the hormonal profile associated with a more traditional lifestyle may be protective among Mongol women.

Maternal weight gain in excess of pregnancy guidelines is related to daughters being overweight 40 years later

BACKGROUND

Exceeding the Institute of Medicine guidelines for pregnancy weight gain increases childhood and adolescent obesity. However, it is unknown if these effects extend to midlife.

OBJECTIVE

We sought to determine if exceeding the Institute of Medicine guidelines for pregnancy weight gain increases risk of overweight/obesity in daughters 40 years later.

STUDY DESIGN

This cohort study is based on adult offspring in the Child Health and Development Studies and the Collaborative Perinatal Project pregnancy cohorts originally enrolled in the 1960s. In 2005 through 2008, 1035 daughters in their 40s were recruited to the Early Determinants of Mammographic Density study. We classified maternal pregnancy weight gain as greater than vs less than or equal to the 2009 clinical guidelines. We used logistic regression to compare the odds ratios of daughters being overweight/obese (body mass index [BMI] ≥25) at a mean age of 44 years between mothers who did not gain or gained more than pregnancy weight gain guidelines, accounting for maternal prepregnant BMI, and daughter body size at birth and childhood. We also examined potential family related confounding through a comparison of sisters using generalized estimating equations, clustered on sibling units and adjusted for maternal age and race.

RESULTS

Mothers who exceeded guidelines for weight gain in pregnancy were more likely to have daughters who were overweight/obese in their 40s (odds ratio [OR], 3.4; 95% confidence interval {CI}, 2.0-5.7). This magnitude of association translates to a relative risk (RR) increase of 50% (RR = 1.5; 95% CI, 1.3-1.6). The association was of the same magnitude when examining only the siblings whose mother exceeded guidelines in 1 pregnancy and did not exceed the guidelines in the other pregnancy. The association was stronger with increasing maternal prepregnancy BMI (P trend < .001). Compared to mothers with BMI <25 who did not exceed guidelines, the relative risks (RR) for having an overweight/obese adult daughter were 1.3 (95% CI, 1.1-1.7), 1.7 (95% CI, 1.4-2.1) and 1.8 (95% CI, 1.5-2.1), respectively, if mothers exceeded guidelines and their prepregnancy BMI was <25, overweight (BMI 25-<30), or obese (BMI >30). This pattern held irrespective of daughters' weight status at birth, at age 4 years, or at age 20 years.

CONCLUSION

Our findings support that obesity prevention before pregnancy and strategies to maintain weight gain during pregnancy within the IOM guidelines might reduce the risk of being overweight in midlife for the offspring.

Comparison of Clinical, Maternal, and Self Pubertal Assessments: Implications for Health Studies

BACKGROUND

Most epidemiologic studies of puberty have only 1 source of pubertal development information (maternal, self or clinical). Interpretation of results across studies requires data on reliability and validity across sources.

METHODS

The LEGACY Girls Study, a 5-site prospective study of girls aged 6 to 13 years (n = 1040) collected information on breast and pubic hair development from mothers (for all daughters) and daughters (if ≥10 years) according to Tanner stage (T1-5) drawings. At 2 LEGACY sites, girls (n = 282) were also examined in the clinic by trained professionals. We assessed agreement (κ) and validity (sensitivity and specificity) with the clinical assessment (gold standard) for both the mothers' and daughters' assessment in the subcohort of 282. In the entire cohort, we examined the agreement between mothers and daughters.

RESULTS

Compared with clinical assessment, sensitivity of maternal assessment for breast development was 77.2 and specificity was 94.3. In girls aged ≥11 years, self-assessment had higher sensitivity and specificity than maternal report. Specificity for both mothers and self, but not sensitivity, was significantly lower for overweight girls. In the overall cohort, maternal and daughter agreement for breast development and pubic hair development (T2+ vs T1) were similar (0.66, [95% confidence interval 0.58-0.75] and 0.69 [95% confidence interval 0.61-0.77], respectively), but declined with age. Mothers were more likely to report a lower Tanner stage for both breast and pubic hair compared with self-assessments.

CONCLUSIONS

These differences in validity should be considered in studies measuring pubertal changes longitudinally when they do not have access to clinical assessments.

Similarity of Serum and Plasma Insulin-like Growth Factor Concentrations

BACKGROUND

Insulin-like growth factors (IGFs) are implicated in many normal physiological processes and pathological states, including cancer. For large consortia projects, it may be necessary to make comparisons among studies with different specimens that were not collected specifically to optimize the measurement of IGFs.

OBJECTIVE

This study aimed to compare IGFs in matched serum and plasma samples.

METHODS

We measured IGF-I, IGF-II, insulin-like growth factor-binding protein (IGFBP)-3, C-peptide, and leptin in serum and ethylenediaminetetraacetic–containing-plasma samples obtained concurrently from 30 healthy women aged 64–80 years in the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial using chemiluminescent or colorimetric enzyme-linked immune assays. Coefficients of variation (CVs) and correlations were determined.

RESULTS

Intraassay CVs ranged from 0.4% for IGFBP-3 to 10% for IGF-II. Mean concentrations of all analytes were higher in the serum, but the differences in mean concentrations of the analytes between serum and plasma were all <11%. Concordance correlation coefficients of matched serum/plasma specimens were 0.92, 0.91, 0.82, 0.96, and 0.99 for IGF-I, IGFBP-3, IGF-II, C-peptide, and leptin, respectively.

CONCLUSION

IGF concentrations measured in serum and plasma are highly correlated but are consistently slightly higher in serum, suggesting that IGF values should be corrected for systematic bias, particularly in consortial efforts when pooling data derived from different specimens.

A migrant study of pubertal timing and tempo in British-Bangladeshi girls at varying risk for breast cancer

Introduction

Earlier menarche is related to subsequent breast cancer risk, yet international differences in the age and tempo of other pubertal milestones and their relationships with body mass index (BMI) are not firmly established in populations at differing risk for breast cancer. We compared age and tempo of adrenarche, thelarche, pubarche, and menarche in a migrant study of Bangladeshi girls to the United Kingdom (UK) and assessed whether differences by migration were explained by differences in BMI.

Methods

Included were groups of Bangladeshi (n =168), British-Bangladeshi (n =174) and white British (n =54) girls, aged 5 to 16 years. Interviewer-administered questionnaires obtained pubertal staging; height and weight were measured. Salivary dehydroepiandrosterone-sulfate concentrations >400 pg/ml defined adrenarche. Median ages of pubertal milestones and hazard ratios (HR) with 95% confidence intervals (CI) were estimated from Weibull survival models.

Results

In all three groups, adrenarche occurred earliest, followed by thelarche, pubarche, and finally menarche. Neither median age at adrenarche (Bangladeshi = 7.2, British-Bangladeshi = 7.4, white British = 7.1; P-trend = 0.70) nor at menarche (Bangladeshi = 12.5, British-Bangladeshi = 12.1, white British = 12.6; P-trend = 0.70) differed across groups. In contrast, median age at thelarche (Bangladeshi = 10.7, British-Bangladeshi = 9.6, white British = 8.7; P-trend <0.01) occurred earlier among girls living in the UK. Compared with Bangladeshi girls, HRs (95% CI) for earlier thelarche were 1.6 (1.1 to 2.4) for British-Bangladeshi girls and 2.6 (1.5 to 4.4) for white British girls (P-trend <0.01), but were attenuated after adjustment for BMI (British-Bangladeshi = 1.1 (0.7 to 1.8), white British = 1.7(1.0 to 3.1); P-trend =0.20).

Conclusions

Thelarche occurred earlier, but puberty progressed slower with increasing exposure to the UK environment; differences were partially explained by greater BMI. The growth environment might account for much of the ethnic differences in pubertal development observed across and within countries.

Electronic supplementary material

The online version of this article (doi:10.1186/s13058-014-0469-8) contains supplementary material, which is available to authorized users.