Childhood Socioeconomic Position and Pubertal Onset in a Cohort of Multiethnic Girls: Implications for Breast Cancer

Lessons Learned from Immigrant Health Cohorts: A Review of the Evidence and Implications for Policy and Practice in Addressing Health Inequities among Asian Americans, Native Hawaiians, and Pacific Islanders

The health of Asian Americans, Native Hawaiians, and Pacific Islanders (AANHPI) is uniquely impacted by structural and social determinants of health (SSDH) shaped by immigration policies and colonization practices, patterns of settlement, and racism. These SSDH also create vast heterogeneity in disease risks across the AANHPI population, with some ethnic groups having high disease burden, often masked with aggregated data. Longitudinal cohort studies are an invaluable tool to identify risk factors of disease, and epidemiologic cohort studies among AANHPI populations have led to seminal discoveries of disease risk factors. This review summarizes the limited but growing literature, with a focus on SSDH factors, from seven longitudinal cohort studies with substantial AANHPI samples. We also discuss key information gaps and recommendations for the next generation of AANHPI cohorts, including oversampling AANHPI ethnic groups; measuring and innovating on measurements of SSDH; emphasizing the involvement of scholars from diverse disciplines; and, most critically, engaging community members to ensure relevancy for public health, policy, and clinical impact.

Applying Life History Theory to Understand Earlier Onset of Puberty: An Adolescent Brain Cognitive Development Cohort Analysis

PURPOSE

Life history theory posits that multigenerational exposure to adversity and deprivation influences childhood growth and development, including pubertal maturation. We applied this ecological, evolutionary theory to examine the contributions of distal and proximal adversity on early puberty, a potentially important marker for population health.

METHODS

Baseline data from 5,645 girls in the adolescent brain cognitive development study were included. Early puberty was defined as midlate/post pubertal development by age 9-11 years. The contributions of multigenerational Black/Indigenous (Black, Indigenous and People of Color [BIPOC]) or Hispanic identities, intergenerational mental health, economic deprivation, personal trauma exposure and mental health, and proximal biological factors of premature birth and body mass index on early puberty were examined with hierarchical modeling.

RESULTS

1,225 girls (21.7%) had early puberty. BIPOC/Hispanic identity, familial adversity, economic deprivation, personal trauma, depression, and a higher body mass index contributed significantly toward early puberty. The effect of multigenerational adversity remained significant across models, but the likelihood of early puberty decreased sequentially for BIPOC and Hispanic youth as proximal adversities were added (e.g., OR decreased from 2.93 to 2.38 for BIPOC youth), supporting a synergistic effect of layered adversity on early puberty.

DISCUSSION

This analysis supports life history theory as a coherent framework to understand early puberty among girls. Findings suggest monitoring pubertal timing as a population health indictor, like birth weight, prematurity, or life expectancy. Addressing early puberty may require policy and social changes to mitigate the negative impact of multiple layers of adversity including racial/ethnic disadvantage, family, and individual mental health and trauma, as well as economic insecurity.

Childhood adversity and accelerated reproductive events: a systematic review and meta-analysis

OBJECTIVE

Accelerated female reproductive events represent the early onset of reproductive events involving puberty, menarche, pregnancy loss, first sexual intercourse, first birth, parity, and menopause. This study aimed to explore the association between childhood adversity and accelerated female reproductive events.

DATA SOURCES

PubMed, Web of Science, and Embase were systematically searched from September 22, 2022 to September 23, 2022.

STUDY ELIGIBILITY CRITERIA

Observational cohort, cross-sectional, and case-control studies in human populations were included if they reported the time of reproductive events for female individuals with experience of childhood adversity and were published in English.

METHODS

Two reviewers independently screened studies, obtained data, and assessed study quality, and conflicts were resolved by a third reviewer. Dichotomous outcomes were evaluated using meta-analysis, and pooled odds ratios and 95% confidence intervals were generated using random-effects models. Moderation analysis and meta-regression were used to investigate heterogeneity.

RESULTS

In total, 21 cohort studies, 9 cross-sectional studies, and 3 case-control studies were identified. Overall, female individuals with childhood adversity were nearly 2 times more likely to report accelerated reproductive events than those with no adversity exposure (odds ratio, 1.91; 95% confidence interval, 1.33-2.76; I2=99.6%; P<.001). Moderation analysis indicated that effect sizes for the types of childhood adversity ranged from an odds ratio of 1.61 (95% confidence interval, 1.23-2.09) for low socioeconomic status to 2.13 (95% confidence interval, 1.14-3.99) for dysfunctional family dynamics. Among the 7 groups based on different reproductive events, including early onset of puberty, early menarche, early sexual initiation, teenage childbirth, preterm birth, pregnancy loss, and early menopause, early sexual initiation had a nonsignificant correlation with childhood adversity (odds ratio, 2.70; 95% confidence interval, 0.88-8.30; I2=99.9%; P<.001). Considerable heterogeneity (I2>75%) between estimates was observed for over half of the outcomes. Age, study type, and method of data collection could explain 35.9% of the variance.

CONCLUSION

The literature tentatively corroborates that female individuals who reported adverse events in childhood are more likely to experience accelerated reproductive events. This association is especially strong for exposure to abuse and dysfunctional family dynamics. However, the heterogeneity among studies was high, requiring caution in interpreting the findings and highlighting the need for further evaluation of the types and timing of childhood events that influence accelerated female reproductive events.

Investigating the Link between Early Life and Breast Anomalies

Several factors during childhood and adolescence are thought to be associated with the development of proliferative benign breast diseases and breast cancer in adulthood. In order to identify them, the authors conducted an extensive review of the literature up to October 2022, searching for clinical studies, reports, and guidelines in English. A thorough Medline/Pubmed and Google scholar database research was performed, investigating the link between diet, exercise, age of menarche, body mass index, ionizing radiation exposure during childhood and adolescence, and proliferative breast diseases and breast cancer in adulthood. A list of keywords, including breast disorders, adolescence, childhood, and breast cancer was included in our search algorithm. Numerous studies concede that the development of breast disease in adulthood is influenced by various risk factors, whose influence begins during early childhood and adolescence.

Thirty-year follow-up of the NICHD Study of Early Child Care and Youth Development (SECCYD): the challenges and triumphs of conducting in-person research at a distance

PURPOSE

The purpose of the current study, The National Institute of Child Health and Human Development (NICHD) Study of Health in Early and Adult Life (SHINE), was to build on the landmark Study of Early Child Care and Youth Development (SECCYD), a longitudinal birth cohort initiated in 1991, by conducting a health-focused follow-up of the now adult participants. This effort has produced an invaluable resource for the pursuit of life course research examining links between early life risk and resilience factors and adulthood health and disease risk.

PARTICIPANTS

Of the 927 NICHD SECCYD participants available for recruitment in the current study, 705 (76.1%) participated in the study. Participants were between 26 and 31 years and living in diverse geographic locations throughout the USA.

FINDINGS TO DATE

In descriptive analyses, the sample exhibited risk on health status indicators, especially related to obesity, hypertension and diabetes. Of particular concern, the prevalence of hypertension (29.4%) and diabetes (25.8%) exceeded national estimates in similar-age individuals. Health behaviour indicators generally tracked with the parameters of poor health status, showing a pattern of poor diet, low activity and disrupted sleep. The juxtaposition of the sample's relatively young age (mean=28.6 years) and high educational status (55.6% college educated or greater) with its poor health status is noteworthy, suggesting a dissociation between health and factors that are typically health protective. This is consistent with observed population health trends, which show a worsening of cardiometabolic health status in younger generations of Americans.

FUTURE PLANS

The current study, SHINE, lays the groundwork for future analyses in which the uniquely robust measures collected as a part of the original NICHD SECCYD will be leveraged to pinpoint specific early life risk and resilience factors as well as the correlates and potential mechanisms accounting for variability in health and disease risk indicators in young adulthood.

The risk of endometriosis by early menarche is recently increased: a meta-analysis of literature published from 2000 to 2020

PURPOSE

The relationship between menarche age and endometriosis has been studied extensively; however, the results were inconsistent due to differences in study dates, populations, and methodology. The goal of this meta-analysis was to see how different research populations, dates, and types affected the estimated risk of endometriosis in early menarche.

METHODS

The terms "endometriosis", "early menarche", and other pertinent terms were searched in PubMed, Medline, and Embase. This meta-analysis comprised 16 papers published between 2000 and 2020, with a start year ranging from 1989 to 2017. Random effects were used to examine endometriosis risks in these articles. Study start years, countries, types (case-control and cohort studies), and quality (Newcastle-Ottawa scale, NOS) were all taken into account in further stratified analysis and meta-regression analyses.

RESULTS

Early menarche (< 12 years) was associated with a significant pooled risk of endometriosis with high heterogeneity (OR = 1.34, 95% CI 1.16-1.54, I² = 72.0%). Stratified analysis showed that this risk was increased in studies started after 2000 (OR = 1.62, 95% CI 0.96-1.35, I² = 74.4%), compared to those before 2000 (OR = 1.13, 95% CI 1.16-1.54, I² = 40.7%); additionally, this risk was higher in low-income countries (OR = 2.11, 95% CI 1.55-2.87, I² = 0%) than in other countries (OR = 1.25, 95% CI 1.09-1.43, I² = 70.6%). These results were further confirmed by meta-regression analysis (both P values < 0.1). No significant differences were found between different study types and NOS scores.

CONCLUSION

Our results suggested an increasing risk of endometriosis with early menarche, which was more noticeable in low-income countries. Large-scale studies are warranted.

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.

Effects of Early Life Adversity on Pubertal Timing and Tempo in Black and White Girls: The National Growth and Health Study

OBJECTIVE

Although exposure to abuse in early life predicts earlier pubertal timing, especially for girls, it is unclear if this association generalizes to nonabuse stressors. In addition, the impact of race on the stress-maturation association remains unknown. To address these issues, we examined whether race moderates the effects of early adversity on pubertal timing and tempo using a longitudinal study design.

METHODS

In a cohort of 9- and 10-year-old Black and White girls, pubertal (areolar and pubic hair) maturation was assessed annually for 7 years. In adulthood, 368 participants (186 Black, 182 White) reported on abuse and nonabuse stressors they experienced from ages 0 to 12 years.

RESULTS

Early life abuse was associated with earlier pubertal timing, as indexed by younger age at menarche (b = -0.22, p = .005, 95% confidence interval [CI] = -0.39 to -0.06) and greater pubic hair development (b = 0.11, p = .003, 95% CI = 0.04 to 0.18), in addition to slower pubertal tempo, as indexed by slower rate of pubic hair (b = -0.03, p < .001, 95% CI = -0.05 to -0.01) and areolar (b = -0.02, p = .02, 95% CI = -0.03 to -0.003) development. These associations were not found for nonabuse adversity. Black girls with early life abuse had greater pubic hair development (b = 0.23, p < .001, 95% CI = 0.12 to 0.35) and were slower in pubic hair tempo (b = -0.07, p < .001, 95% CI = -0.09 to -0.04) than their White counterparts.

CONCLUSIONS

Screening for early life abuse may help address health disparities related to earlier pubertal timing.

Socioeconomic Status Is Related to Pubertal Development in a German Cohort

INTRODUCTION

Current health literature suggests that there has been a decline in the age of pubertal onset and that pubertal onset/duration of puberty may, besides weight status, be influenced by socioeconomic context.

OBJECTIVE

The goal of this study was to determine whether pubertal onset/duration and puberty-triggering hormones luteinizing hormone (LH) and follicle-stimulating hormone (FSH) vary according to socioeconomic status (SES). Moreover, we aimed to propose cutoff values of serum LH and FSH for predicting gonadarche in boys.

METHODS

2,657 apparently healthy children and adolescents between 5.5 and 18 years from the area of Leipzig were recruited from the LIFE Child study. Age at pubertal onset/end of puberty was given in 738/573 children, respectively. Anthropometric parameters of puberty, blood measurements of LH and FSH, and questionnaires assessing SES were evaluated.

RESULTS

Lower SES was associated with earlier thelarche and longer duration of puberty in overweight/obese girls, whereas age of menarche was not affected. In boys with low SES, a trend versus earlier puberty onset can be seen. Lower SES was significantly associated with boys' age at mutation. No significant differences in boys' and girls' serum levels of LH and FSH during puberty according to SES were observed. Serum LH levels of 0.56 IU/L and serum FSH levels of 1.74 IU/L showed the best prediction of gonadarche in boys.

CONCLUSION

Puberty onset/duration and boys' age at mutation is affected by SES. The proposed cutoff levels for serum LH and FSH could provide a serological tool to determine gonadarche in boys.

Childhood Overweight and Obesity and Pubertal Onset Among Mexican-American Boys and Girls in the CHAMACOS Longitudinal Study

Secular trends in earlier initiation of puberty have been observed in recent decades. One risk factor appears to be increases in adiposity, as measured by body mass index. This trend is particularly notable among Latino populations, who have higher rates of overweight/obesity compared with non-Latino White youth. Previous research has focused primarily on White girls, resulting in data gaps regarding male puberty and among potentially high-risk populations. Using data from the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS) study, we examined body mass index at age 5 years (2005-2006) and multiple markers of pubertal onset, assessed repeatedly and longitudinally at 7 in-person visits, starting at age 9 and continuing through age 14 (2009-2015), among 336 Mexican Americans in Salinas, California. We observed no associations among boys, but found significantly earlier thelarche in overweight (HR = 1.7, 95% CI: 1.1, 2.7) and obese girls (HR = 1.5, 95% CI: 1.0, 2.4), menarche in overweight girls (HR = 1.6; CI: 1.0, 2.4), and pubarche in obese girls (HR = 1.9; CI: 1.2, 3.0), compared with normal-weight girls. This study examined an understudied population and included key covariates, such as birth weight and early adverse events, which are typically omitted in studies.

Neighborhood Socioeconomic Disadvantage and Childhood Body Mass Index Trajectories From Birth to 7 Years of Age

BACKGROUND

The epidemic of increasing childhood overweight and obesity is a major global health concern, with local contextual factors identified as possible contributors. Robust research is needed to establish an evidence base supporting health policy decisions to reverse the trend. We aimed to examine the association between neighborhood socioeconomic disadvantage and trajectories of body mass index (BMI) from birth to age 7.

METHODS

The present study included 11,023 children born within the Southwest Finland Birth Cohort who were free of severe conditions affecting growth with adequate exposure and growth data. We obtained child growth data until school age from municipal follow-up clinics. We based cumulative childhood neighborhood socioeconomic disadvantage on the average annual income, unemployment, and level of education in a residential area defined using a geographic grid at a spatial resolution of 250 m by 250 m.

RESULTS

Cumulative neighborhood socioeconomic disadvantage was associated with distinct childhood BMI z score trajectories from birth to age 7. Despite being born in the lowest BMI z scores, children growing up in disadvantaged neighborhoods subsequently exhibited a trajectory of increasing BMI z scores starting at 4 years of age, ending up with a higher risk of overweight at the end of the follow-up (30%) as compared with children living in more affluent neighborhoods (22%). The corresponding risk of obesity was 5 % for those in affluent neighborhoods and 9 % and those in disadvantaged neighborhoods.

CONCLUSION

Cumulative exposure to neighborhood socioeconomic disadvantage is independently associated with unfavorable BMI development and obesity in childhood.

Early-life exposures and age at thelarche in the Sister Study cohort

BACKGROUND

Early age at breast development (thelarche) has been associated with increased breast cancer risk. Average age at thelarche has declined over time, but there are few established risk factors for early thelarche. We examined associations between pre- and postnatal exposures and age at thelarche in a US cohort of women born between 1928 and 1974.

METHODS

Breast cancer-free women ages 35-74 years who had a sister diagnosed with breast cancer were enrolled in the Sister Study from 2003 to 2009 (N = 50,884). At enrollment, participants reported information on early-life exposures and age at thelarche, which we categorized as early (≤ 10 years), average (11-13 years), and late (≥ 14 years). For each exposure, we estimated odds ratios (ORs) and 95% confidence intervals (CIs) for early and late thelarche using polytomous logistic regression, adjusted for birth cohort, race/ethnicity and family income level in childhood.

RESULTS

Early thelarche was associated with multiple prenatal exposures: gestational hypertensive disorder (OR = 1.25, 95% CI 1.09-1.43), diethylstilbestrol use (OR = 1.23, 95% CI 1.04-1.45), smoking during pregnancy (OR = 1.20, 95% CI 1.13-1.27), young maternal age (OR 1.30, 95% CI 1.16-1.47 for < 20 vs. 25-29 years), and being firstborn (OR = 1.25, 95% CI 1.17-1.33). Birthweight < 2500 g and soy formula use in infancy were positively associated with both early and late thelarche.

CONCLUSIONS

Associations between pre- and postnatal exposures and age at thelarche suggest that the early-life environment influences breast development and therefore may also affect breast cancer risk by altering the timing of pubertal breast development.

Childhood Socioeconomic Status and Menarche: A Prospective Study

PURPOSE

The relationship between socioeconomic status (SES) and menarche has implications for understanding social level influences on early life development and adult disease, including breast cancer, but remains ill defined. We report here results from the Breast Cancer and the Environment Research Program, which permitted a longitudinal study of age at menarche in relationship to childhood SES in a diverse cohort of 1,069 girls across three urban areas of the United States.

METHODS

We assessed the association of SES index quintiles with age at pubertal onset with breast budding and subsequent tempo to the age at menarche between 2004 and 2015 using multiple-event Cox regression models to estimate hazard ratios and 95% confidence intervals.

RESULTS

In an unadjusted model, lower SES was predictive of both earlier pubertal onset and tempo and thus earlier age at menarche in trends across quintiles. After adjusting for the potentially mediating effects of body mass index, SES trends remained significant for both outcomes. After adjusting for both body mass index and race/ethnicity, the association with SES remained substantial for pubertal onset but was much diminished and nonsignificant for tempo and thus age at menarche.

CONCLUSIONS

These results suggest that a lower SES environment and social adversity affect the age at menarche primarily by hastening pubertal onset rather than by shortening tempo.

Girls' Pubertal Timing and Tempo and Mental Health: A Longitudinal Examination in an Ethnically Diverse Sample

PURPOSE

Earlier timing and faster tempo of puberty have been linked to adolescents' poor mental health. Previous research rarely adjusted for childhood mental health, did not use physical examination to assess puberty, and excluded Latinas and Asian Americans. This study addressed these limitations.

METHODS

We followed 822 girls, recruited at ages 6-8, for 8 years. Breast and pubic hair development and anxiety and depressive symptoms were assessed prospectively and repeatedly. Structural equation models tested whether pubertal timing and tempo were associated with adolescent mental health symptoms and whether associations varied by ethnicity. Models were adjusted for childhood mental health symptoms, body mass index, and family income.

RESULTS

Earlier breast development was associated with higher depressive symptoms among whites (β = -.19; p < .01) and higher anxiety symptoms among Latinas (β = -.26; p < .05), but lower depressive symptoms among Asians (β = .24, p < .05). Later pubic hair development (b = .24; p < .05) and faster pubic hair tempo (β = .26; p < .01) were associated with higher anxiety symptoms among Latinas. Faster pubic hair tempo was associated with lower depressive symptoms among Asians (β = -.34; p < .05). Tempo of breast development showed no associations.

CONCLUSIONS

Findings confirmed that earlier breast development was associated with higher mental health symptoms for Latina and white girls but was protective among Asians. Results for pubic hair and pubertal tempo were inconsistent, requiring future examination. While targeted interventions to prevent mental health problems among early-maturing girls are critical, there is variability among who might benefit most.

Trajectory of Body Mass Index from Ages 2 to 7 Years and Age at Peak Height Velocity in Boys and Girls

OBJECTIVE

To examine the associations between body mass index (BMI) at 2-4 years and 5-7 years and age at peak height velocity (APHV), an objective measure of pubertal timing, among boys and girls from predominantly racial minorities in the US that have been historically underrepresented in this research topic.

STUDY DESIGN

This study included 1296 mother-child dyads from the Boston Birth Cohort, a predominantly Black and low-income cohort enrolled at birth and followed prospectively during 1998-2018. The exposure was overweight or obesity, based on Centers for Disease Control and Prevention reference standards. The outcome was APHV, derived using a mixed effects growth curve model. Multiple regression was used to estimate the overweight or obesity-APHV association and control for confounders.

RESULTS

Obesity at 2-4 years was associated with earlier APHV in boys (B in years, -0.19; 95% CI, -0.35 to -0.03) and girls (B, -0.22; 95% CI, -0.37 to -0.07). Obesity at 5-7 years was associated with earlier APHV in boys (B, -0.18; 95% CI, -0.32 to -0.03), whereas overweight and obesity at 5-7 years were both associated with earlier APHV in girls (overweight: B, -0.24; 95% CI, -0.40 to -0.08; obesity: B, -0.27; 95% CI, -0.40 to -0.13). With BMI trajectory, boys with persistent overweight or obesity and girls with overweight or obesity at 5-7 years, irrespective of overweight or obesity status at 2-4 years, had earlier APHV.

CONCLUSIONS

This prospective birth cohort study found that overweight or obesity during 2-7 years was associated with earlier pubertal onset in both boys and girls. The BMI trajectory analyses further suggest that reversal of overweight or obesity may halt the progression toward early puberty.

Early-Life Risk Factors for Breast Cancer - Prospective Follow-up in the Northern Finland Birth Cohort 1966

BACKGROUND

While some risk factors for breast cancer have been confirmed, less is known about the role of early biological and social risk factors for breast cancer in adult life.

METHODS

In a prospective follow-up in the Northern Finland Birth Cohort 1966 consisting of 5,308 women, 120 breast cancers were reported via national registers by the end of 2018. Early risk factors were examined with univariate and multivariate analyses using Cox regression analysis. The main results are reported with HRs and their 95% confidence intervals (CI).

RESULTS

In the multivariate-adjusted models, women whose mothers lived in urban areas (HR, 1.68; 95% CI, 1.13-2.51) during pregnancy, were low educated (HR, 2.40; 95% CI, 1.30-4.45), and had been diagnosed with breast cancer (HR, 1.97; 95% CI, 1.09-3.58) had a higher risk for breast cancer in adult life. Lower BMI at the age of 14 associated nonsignificantly with the risk of breast cancer (Mann-Whitney U test, P = 0.087). No association between birth size and breast cancer risk in adult life was found.

CONCLUSIONS

Early-life residence and socioeconomic conditions may have an impact on developing breast cancer in women in adult life. All breast cancer cases of this study were relatively young, and most of them are assumed to be premenopausal.

IMPACT

This study is one of a few prospective birth cohort studies to examine early-life socioeconomic factors and breast cancer risk in adult life. This study is limited due to small number of cases.

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.

Early Life Adversity and Pubertal Timing: Implications for Cardiometabolic Health

OBJECTIVE

To identify early life adversity (ELA) risk factors for earlier pubertal timing, itself a risk factor for poor cardiometabolic health, and to determine whether such ELA-related risk may be mediated by pre-pubertal body mass index (BMI).

METHODS

Subjects included 426 female participants in a prospective birth cohort study, the NICHD Study of Early Child Care and Youth Development. Survival analysis models were fit to examine ELA exposures, representing childhood socioeconomic status (SES), maternal sensitivity, mother-child attachment, and negative life events, along with child health indicators and covariates, in relation to pubertal timing outcomes, including age at menarche and ages at Tanner stage II for breast and pubic hair development.

RESULTS

Higher childhood SES emerged as an independent predictor of older age at menarche, showing each one standard deviation increase in childhood SES corresponded to a 1.3% increase in age at menarche (factor change = 1.013; 1.003-1.022; p < .01), but did not predict breast or pubic hair development (ps > .05). In mediation analyses, indirect (mediated) effects of mother-child attachment on the pubertal timing outcomes, via pre-pubertal BMI, were all statistically significant (ps < .05).

CONCLUSIONS

Higher childhood SES predicted directly, and secure (vs. insecure) mother-child attachment predicted indirectly (via pre-pubertal BMI), later pubertal timing, suggesting these factors may protect girls from earlier pubertal development. By extension, clinical implications are that intervention strategies designed to lessen ELA- and pre-pubertal obesity-related risk may be effective in remediating life course pathways linking ELA, accelerated pubertal development, and cardiometabolic risk.

Association between indicators of systemic inflammation biomarkers during puberty with breast density and onset of menarche

Background

Systemic inflammation may play a role in shaping breast composition, one of the strongest risk factors for breast cancer. Pubertal development presents a critical window of breast tissue susceptibility to exogenous and endogenous factors, including pro-inflammatory markers. However, little is known about the role of systemic inflammation on adolescent breast composition and pubertal development among girls.

Methods

We investigated associations between circulating levels of inflammatory markers (e.g., interleukin-6 (IL-6), tumor necrosis factor receptor 2 (TNFR2), and C-reactive protein (CRP)) at Tanner stages 2 and 4 and breast composition at Tanner stage 4 in a cohort of 397 adolescent girls in Santiago, Chile (Growth and Obesity Cohort Study, 2006–2018). Multivariable linear models were used to examine the association between breast composition and each inflammatory marker, stratifying by Tanner stage at inflammatory marker measurement. Accelerated failure time models were used to evaluate the association between inflammatory markers concentrations at each Tanner stage and time to menarche.

Results

In age-adjusted linear regression models, a doubling of TNFR2 at Tanner 2 was associated with a 26% (95% CI 7–48%) increase in total breast volume at Tanner 4 and a 22% (95% CI 10–32%) decrease of fibroglandular volume at Tanner 4. In multivariable models further adjusted for body fatness and other covariates, these associations were attenuated to the null. The time to menarche was 3% (95% CI 1–5%) shorter among those in the highest quartile of IL-6 at Tanner 2 relative to those in the lowest quartile in fully adjusted models. Compared to those in the lowest quartile of CRP at Tanner 4, those in the highest quartile experienced 2% (95% CI 0–3%) longer time to menarche in multivariable models.

Conclusions

Systemic inflammation during puberty was not associated with breast volume or breast density at the conclusion of breast development among pubertal girls after adjusting for body fatness; however, these circulating inflammation biomarkers, specifically CRP and IL-6, may affect the timing of menarche onset.

Child-related and parental predictors for thelarche in a general population of girls: the PANIC study

BACKGROUND

Obesity has been associated with earlier thelarche, whereas other predictors for it remain unclear.

METHODS

We studied child-related and parental predictors for earlier thelarche in 195 girls aged 6-8 years followed up for 2 years. A physician evaluated breast development by inspection and palpation. Body fat percentage (BF%) was measured by dual-energy X-ray absorptiometry, diet by food records, and physical activity and sedentary time by body movement and heart rate monitors. Parental education, smoking, and alcohol consumption and household income were assessed by questionnaires. Gestational age, birth weight, and maternal prepregnancy BMI were obtained from hospital registers. Predictors for thelarche were examined using logistic regression analysis adjusted for age and follow-up time.

RESULTS

The incidence of thelarche during 2 years increased by 11% (OR 1.11, CI 1.06-1.17, p < 0.001) for 1 unit increase in baseline BF%. Girls with a smoking parent had a 2.64 (95% CI 1.21-5.77, p = 0.015) times higher incidence of thelarche than other girls. The associations of lower parental education and higher maternal prepregnancy BMI with the higher incidence of thelarche were largely explained by BF%. Other possible predictors were not associated with thelarche.

CONCLUSIONS

Higher BF% and exposure to tobacco smoke are independent predictors for earlier thelarche.

Perfluorooctanoate and changes in anthropometric parameters with age in young girls in the Greater Cincinnati and San Francisco Bay Area

METHODS

We conducted a study of per- and polyfluoroalkyl substance biomarkers, including PFOA, in girls from Greater Cincinnati (CIN, N = 353) and the San Francisco Bay Area (SFBA, N = 351). PFOA was measured in the baseline serum sample collected in 2004-2007 of 704 girls at age 6-8 years. Mixed effects models were used to derive the effect of PFOA on BMI, waist-to-height and waist-to-hip ratios over increasing age in this longitudinal cohort.

RESULTS

Median PFOA serum concentrations were 7.3 (CIN) and 5.8 (SFBA) ng/mL, above the U.S. population median for children 12-19 years in 2005-2006 (3.8 ng/mL). Log-transformed serum PFOA had a strong inverse association with BMIz in the CIN girls (p = 0.0002) and the combined two-site data (p = 0.0008); the joint inverse effect of PFOA and Age*PFOA weakened at age at 10-11 years. However, in the SFBA group alone, the relationship was not significant (p = 0.1641) with no evidence of changing effect with age. The effect of PFOA on waist:height ratio was similar to BMIz at both sites, but we did not find a significant effect of PFOA on waist:hip ratio in either the CIN or SFBA girls.

CONCLUSIONS

PFOA is associated with decreased BMI and waist:height ratio in young girls, but the strength of the relationship decreases with age. Site heterogeneity may be due to greater early life exposure in Cincinnati.

DISCLAIMER

The findings and conclusions in this report are those of the authors and do not necessarily represent the official position of the Centers for Disease Control and Prevention. Use of trade names is for identification only and does not imply endorsement by the CDC, the Public Health Service, or the US Department of Health and Human Services.

Developmental Adaptation to Stress: An Evolutionary Perspective

The assumption that early stress leads to dysregulation and impairment is widespread in developmental science and informs prevailing models (e.g., toxic stress). An alternative evolutionary–developmental approach, which complements the standard emphasis on dysregulation, proposes that early stress may prompt the development of costly but adaptive strategies that promote survival and reproduction under adverse conditions. In this review, we survey this growing theoretical and empirical literature, highlighting recent developments and outstanding questions. We review concepts of adaptive plasticity and conditional adaptation, introduce the life history framework and the adaptive calibration model, and consider how physiological stress response systems and related neuroendocrine processes may function as plasticity mechanisms. We then address the evolution of individual differences in susceptibility to the environment, which engenders systematic person–environment interactions in the effects of stress on development. Finally, we discuss stress-mediated regulation of pubertal development as a case study of how an evolutionary–developmental approach can foster theoretical integration.