Pubertal Timing Across Asian American, Native Hawaiian, and Pacific Islander Subgroups.

Importance: Earlier puberty is associated with adverse health outcomes, such as mental health issues in adolescence and cardiometabolic diseases in adulthood. Despite rapid growth of the Asian American, Native Hawaiian, and Pacific Islander populations in the US, limited research exists on their pubertal timing, potentially masking health disparities. Objective: To examine pubertal timing among Asian American, Native Hawaiian, and Pacific Islander children and adolescents by disaggregating ethnic subgroups. Design, Setting, and Participants: This retrospective cohort study included Asian American, Native Hawaiian, and Pacific Islander youths aged 5 to 18 years assessed for pubertal development at Kaiser Permanente Northern California, a large, integrated health care delivery system. Follow-up occurred from March 2005, through December 31, 2019. Data were analyzed in October 2023. Exposure: Race and ethnicity, categorized into 11 ethnic subgroups: Asian Indian, Chinese, Filipino, Japanese, Korean, Native Hawaiian and Pacific Islander, Other South Asian, Other Southeast Asian, Vietnamese, multiethnic, and multiracial. Main Outcomes and Measures: Pubertal timing was determined using physician-assessed sexual maturity ratings (SMRs). Outcomes included the median age at transition from SMR 1 (prepubertal) to SMR 2 or higher (pubertal) for onset of genital development (gonadarche) in boys, breast development (thelarche) in girls, and pubic hair development (pubarche) in both boys and girls. Results: In this cohort of 107 325 Asian American, Native Hawaiian, and Pacific Islander children and adolescents (54.61% boys; 12.96% Asian Indian, 22.24% Chinese, 26.46% Filipino, 1.80% Japanese, 1.66% Korean, 1.96% Native Hawaiian and Pacific Islander, 0.86% Other South Asian, 3.26% Other Southeast Asian, 5.99% Vietnamese, 0.74% multiethnic, and 22.05% multiracial), the overall median ages for girls' pubarche and thelarche were 10.98 years (95% CI, 10.96-11.01 years) and 10.13 years (95% CI, 10.11-10.15 years), respectively. For boys' pubarche and gonadarche, median ages were 12.08 years (95% CI, 12.06-12.10 years) and 11.54 years (95% CI, 11.52-11.56 years), respectively. Differences between subgroups with earliest and latest median age at onset were 14 months for girls' pubarche, 8 months for thelarche, 8 months for boys' pubarche, and 4 months for gonadarche. In general, Asian Indian, Native Hawaiian and Pacific Islander, and Other South Asian subgroups had the earliest ages at onset across pubertal markers, while East Asian youths exhibited the latest onset. Restricting to those with healthy body mass index did not substantially change the findings. Conclusions and Relevance: In this cohort study of Asian American, Native Hawaiian, and Pacific Islander children and adolescents, pubertal timing varied considerably across ethnic subgroups. Further investigation is warranted to assess whether these differences contribute to observed health disparities in adulthood, such as type 2 diabetes and cardiovascular diseases.

Alanine aminotransferase elevation varies by ethnicity among Asian and Pacific Islander children with overweight or obesity.

BACKGROUND: Limited research on alanine aminotransferase (ALT) screening for metabolic dysfunction-associated steatotic liver disease (MASLD) among US Asian/Pacific Islander (PI) children necessitates investigation in this heterogeneous population. OBJECTIVE: Examine ALT elevation among Asian/PI children with overweight or obesity. METHODS: Elevated ALT prevalence (clinical threshold) and association with body mass index ≥85th percentile were compared among 18 402 Asian/PI and 25 376 non-Hispanic White (NHW) children aged 9-17 years using logistic regression. RESULTS: ALT elevation was more prevalent among Asian/PI (vs. NHW) males with overweight (4.0% vs. 2.7%), moderate (7.8% vs. 5.3%) and severe obesity (16.6% vs. 11.5%), and females with moderate (5.1% vs. 3.0%) and severe obesity (10.2% vs. 5.2%). Adjusted odds of elevated ALT were 1.6-fold and ~2-fold higher for Asian/PI (vs. NHW) males and females (with obesity), respectively. Filipino, Chinese and Southeast Asian males had 1.7-2.1-fold higher odds, but Native Hawaiian/PI (NHPI) and South Asian males did not significantly differ (vs. NHW). Filipina and Chinese females with obesity had >2-fold higher odds, Southeast and South Asian females did not differ and NHPI findings were mixed (vs. NHW). CONCLUSION: High elevated ALT prevalence among Asian/PI children with overweight and obesity emphasizes the need for MASLD risk assessment and examination of ethnic subgroups.

Hemoglobin A1c and Type 2 Diabetes Incidence Among Adolescents With Overweight and Obesity.

Importance: With the increase in prediabetes among adolescents with overweight and obesity, identifying those at highest risk for type 2 diabetes (T2D) can support prevention strategies. Objective: To assess T2D risk by hemoglobin A1c (HbA1c) levels among adolescents with overweight and obesity. Design, Setting, and Participants: This retrospective cohort study was conducted using data for January 1, 2010, to December 31, 2019, from a large California health care system. The study population comprised adolescents aged 10 to 17 years who had a body mass index (BMI; calculated as weight in kilograms divided by height in meters squared) at or above the 85th percentile, had HbA1c measured during 2010 to 2018, and did not have preexisting diabetes. Data abstraction and analyses were conducted from January 1, 2020, to November 16, 2023. Exposures: Baseline HbA1c, with covariates including BMI category (overweight: 85th to <95th percentile; moderate obesity: 100% to <120% of 95th percentile; or severe obesity: ≥120% of 95th percentile), age, sex, race and ethnicity, and Neighborhood Deprivation Index score. Main Outcomes and Measures: The main outcome was incident T2D during follow-up through 2019, including cumulative incidence and multivariable hazard ratios (HRs) with 95% CIs using Cox proportional hazard regression analyses. Results: This study included 74 552 adolescents with a mean (SD) age of 13.4 (2.3) years. More than half (50.6%) were female; 26.9% of individuals had overweight, 42.3% had moderate obesity, and 30.8% had severe obesity. Individuals identified as Asian or Pacific Islander (17.6%), Black (11.1%), Hispanic (43.6%), White (21.6%), and other or unknown race or ethnicity (6.1%). During follow-up, 698 adolescents (0.9%) developed diabetes, and 626 (89.7%) had T2D; 72 individuals (10.3%) who had type 1, secondary, or other diabetes were censored. The overall T2D incidence was 2.1 (95% CI, 1.9-2.3) per 1000 person-years, with a 5-year cumulative incidence of 1.0% (95% CI, 0.9%-1.1%). Higher baseline HbA1c (from <5.5% to 5.5%-5.6%, 5.7%-5.8%, 5.9%-6.0%, 6.1%-6.2%, and 6.3-6.4%) was associated with higher 5-year cumulative T2D incidence (from 0.3% [95% CI, 0.2%-0.4%] to 0.5% [0.4%-0.7%], 1.1% [0.8%-1.3%], 3.8% [3.2%-4.7%], 11.0% [8.9%-13.7%], and 28.5% [21.9%-36.5%], respectively). In addition, higher baseline HbA1c was associated with greater T2D risk (reference [HbA1c <5.5%]: HR, 1.7 [95% CI, 1.3-2.2], 2.8 [2.1-3.6], 9.3 [7.2-12.1], 23.3 [17.4-31.3], and 71.9 [51.1-101.1], respectively). Higher BMI category, older age, female sex, and Asian or Pacific Islander race (HR, 1.7 [95% CI, 1.3-2.2]), but not Black race or Hispanic ethnicity (compared with White race), were also independent indicators of T2D. In stratified analyses, incremental risk associated with higher HbA1c was greater for Asian or Pacific Islander and White adolescents than for Black and Hispanic adolescents. Conclusions and Relevance: In this cohort study of adolescents with overweight and obesity, T2D risk increased substantially with baseline HbA1c above 6.0%. Risk varied by BMI, age, sex, and race and ethnicity. These findings suggest that diabetes surveillance in adolescents should be tailored to optimize identification among high-risk subgroups.

Identifying modifiable obesogenic behaviors among Latino adolescents in primary pediatric care.

Latino adolescents engage in more obesogenic behaviors, including sedentary behaviors and sugary drink consumption, than White adolescents. However, it is unclear whether engagement in obesogenic behaviors differs within the Latino population. Cross-sectional data were examined from Latino adolescents ages 13-17 with a well-child visit (2016-2019) in an integrated healthcare system. Adolescents self-reported on four daily obesogenic behaviors: 1) consuming < 5 servings of fruits/vegetables; 2) drinking > 1 juice/soda; 3) exercising/playing sports < 60 min; and 4) > 2 h screen time. A composite variable of ≥ 3 self-reported behaviors was constructed. Multivariable logistic regression was used to examine associations between obesogenic behaviors with age category (13-15 or 16-17 years), sex, household language preference (English/Spanish), neighborhood deprivation index (NDI quartiles), and body mass index (BMI). Among 77,514 Latino adolescents (mean age 14.7 ± 1.4; 50 % female), 23 % lived in Spanish-speaking households, 43 % resided in census tracts with the highest (most deprived) NDI quartile, and 45 % had an overweight or obese BMI. Older (vs younger) adolescents had higher odds of insufficient fruit/vegetable intake (OR 1.20; CI 1.17-1.24), greater sedentary behavior (OR 1.51; 1.46-1.56), and reporting > 2 h screen time (OR 1.07; 1.03-1.11). Adolescents in the 4th (vs 1st) NDI quartile (OR 1.34; 1.26-1.42) and those with obesity (vs healthy weight) (OR 1.55; 1.42-1.70 for class 3 obesity) had higher odds of ≥ 3 obesogenic behaviors. In conclusion, among Latino adolescents, older age, obesity, and living in more deprived neighborhoods were associated with greater obesogenic behaviors. Identifying adolescents more likely to engage in obesogenic behaviors can inform targeted lifestyle interventions.

Associations Between Childhood Obesity and Pubertal Timing Stratified by Sex and Race/Ethnicity.

Earlier puberty has been associated with numerous adverse mental, emotional, and physical health outcomes. Obesity is a known risk factor for earlier puberty in girls, but research with boys has yielded inconsistent findings. We examined sex- and race/ethnicity-specific associations between childhood obesity and puberty in a multiethnic cohort of 129,824 adolescents born at a Kaiser Permanente Northern California medical facility between 2003 and 2011. We used Weibull regression models to explore associations between childhood obesity and breast development onset (thelarche) in girls, testicular enlargement onset (gonadarche) in boys, and pubic hair development onset (pubarche) in both sexes, adjusting for important confounders. Clear dose-response relationships were observed. Boys with severe obesity had the greatest risk for earlier gonadarche (hazard ratio = 1.23, 95% confidence limit: 1.15, 1.32) and pubarche (hazard ratio = 1.44, 95% confidence limit: 1.34, 1.55), while underweight boys had delayed puberty compared with peers with normal body mass index. A similar dose-response relationship was observed in girls. There were significant interactions between childhood body mass index and race/ethnicity. Childhood obesity is associated with earlier puberty in both boys and girls, and the magnitude of the associations may vary by race/ethnicity. Prevention of childhood obesity may delay pubertal timing and mitigate health risks associated with both conditions.

Ethnic diversity and burden of polycystic ovary syndrome among US adolescent females.

OBJECTIVES: Polycystic Ovary Syndrome (PCOS) is a common female endocrine disorder presenting as early as adolescence. Recent data suggest that Asians may be at increased risk. This study examines PCOS prevalence by race/ethnicity in a large, diverse population of adolescent females. METHODS: This retrospective study included 244,642 females (ages 13-17) with well-child visits during 2012-2018 in a Northern California healthcare system. Race/ethnicity and Asian ethnicity were classified using self-reported data. Body mass index was classified as healthy, overweight, and moderate/severe obesity. PCOS was determined by clinical diagnosis within one year of the visit. RESULTS: The overall prevalence of PCOS was 0.7% and increased substantially with weight. Among those with obesity, PCOS prevalence was 4.2, 2.9, 2.4, 2.1% in Asian/Pacific Islander (PI), Hispanic/Latina, Non-Hispanic White, Black adolescents and 7.8, 6.7, 5.7, 3.4% in South Asian, Chinese, Filipina, Native Hawaiian/PI adolescents, respectively. Compared to White adolescents, Asian/PIs had two-fold higher risk of PCOS, and Hispanic/Latinas had 1.3-fold higher risk. Compared to Chinese adolescents, South Asians had 1.7-fold higher risk, while Native Hawaiian/PIs had half the risk. CONCLUSIONS: The increased burden of diagnosed PCOS in Asian/PI and Hispanic/Latina adolescents, especially those with obesity, calls for further examination and clinical surveillance of at-risk populations.

Associations between infant growth and pubertal onset timing in a multiethnic prospective cohort of girls.

BACKGROUND: Early puberty increases risk of adverse health conditions throughout the life course. US girls are experiencing earlier puberty without clear reasons. Studies suggest early life factors, such as infant growth, may influence pubertal timing. We assessed the associations between infant growth and onset of breast development (thelarche), pubic hair development (pubarche), and menarche in girls. METHODS: A prospective cohort of girls born at a Kaiser Permanente Northern California medical facility in 2005-11 was used. Weight-for-age z-scores were calculated at birth and 24 months. Difference in z-scores greater than 0.67 represent rapid "catch-up" growth, less than -0.67 represent delayed "catch-down" growth, and between -0.67 and 0.67 represent "normal" growth. Pubertal onset was measured using clinician-assessed sexual maturity ratings (SMRs) and defined as the age at transition from SMR 1 to SMR 2 + for both thelarche and pubarche. SMR data was collected through June 2020. Menarche was analyzed as a secondary outcome. Weibull and modified Poisson regression models were used. Models were adjusted for potential confounders. RESULTS: There were 15,196 girls included in the study. Approximately 30.2% experienced catch-up growth, 25.8% experienced catch-down growth, and 44% had normal growth. Girls with catch-up growth had increased risk of earlier thelarche (hazard ratio = 1.26, 95% confidence interval (CI): 1.18, 1.35), pubarche (1.38, 95% CI: 1.28, 1.48), and menarche (< 12y, relative risk = 1.52, 95% CI: 1.36, 1.69) compared to those with normal growth, after adjusting for covariates. These associations were partially mediated by childhood body mass index. Catch-down growth was associated with later pubertal onset. CONCLUSIONS: Girls who experience infant catch-up growth have higher risk of earlier pubertal development compared to girls with normal growth and the associations are partially explained by childhood obesity. This information may help clinicians to monitor girls who are at high risk of developing earlier.

The Prevalence of Elevated Alanine Aminotransferase Levels Meeting Clinical Action Thresholds in Children with Obesity in Primary Care Practice.

Using a clinically actionable threshold for alanine aminotransferase to define suspected nonalcoholic fatty liver disease in US children with obesity, the risk of suspected nonalcoholic fatty liver disease was highest for Asian and Hispanic race/ethnicity, male sex, and severe obesity.

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.

Style of meal service and feeding practices among Mexican American fathers and mothers: An analysis of video-recorded children's evening mealtime at home.

The aim of this study was to examine video-recorded observations of evening family mealtime at home among Mexican American children to help elucidate style of meal service, fathers' and mothers' feeding practices and child's eating behavior. Consistent with guidelines for coding behaviors, we analyzed observational data of evening mealtimes of 71 Mexican American children aged eight to 10 years. Regarding style of meal service, in almost all cases (96%), parents plated the child's food, with more available on the table or counter in 40% of the observations. Mothers almost always served the child (94%). Regarding parental feeding practices, parents used positive involvement in meals (80%), pressure to eat (42%) and restriction of food (9%). Using food as a reward to control behavior was never used by either parent. The majority (75%) of children requested or negotiated to eat less food, or only eat certain items. In Mexican American families, both mothers and fathers play a role in family mealtimes and both use positive involvement in child's meals, and to a lesser extent pressure to eat, with their children aged eight to 10 years. To help reduce the obesity epidemic, intervention strategies are needed, which integrate the family, a plating style of meal and parental feeding practices that promote healthy eating in the home. To reduce obesity among Mexican American children, interventions that focus on parental positive involvement in child's meal and maintenance of home cooked meals could have a positive impact on the entire family.

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 (ß = -.19; p < .01) and higher anxiety symptoms among Latinas (ß = -.26; p < .05), but lower depressive symptoms among Asians (ß = .24, p < .05). Later pubic hair development (b = .24; p < .05) and faster pubic hair tempo (ß = .26; p < .01) were associated with higher anxiety symptoms among Latinas. Faster pubic hair tempo was associated with lower depressive symptoms among Asians (ß = -.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.

Early life household intactness and timing of pubertal onset in girls: a prospective cohort study.

BACKGROUND: Girls who experience early-life familial stress may have heightened risk of early puberty, which has adverse implications for adolescent and adult health. We assessed the association between household intactness and pubertal onset using a racially/ethnically diverse cohort of girls from Northern California. METHODS: A prospective cohort study of 26,044 girls born in 2003-10. Girls living with both parents from birth up to 6 years were considered to come from "intact" households while others constituted "non-intact" households. Pubertal development was measured using pediatrician-assessed Tanner staging for breast and pubic hair. Pubertal onset was defined as the transition from Tanner Stage 1 to 2+ for breast (thelarche) and pubic hair (pubarche). Menarche data was collected from routine well-child questionnaires. Weibull regression models accommodating left, right, and interval censoring were used to determine risk of earlier thelarche and pubarche, and logistic regressions were used to assess the risk of early menarche (age < 12). RESULTS: Girls exposed to non-intact households before age 2 years were at increased risk for earlier thelarche and pubarche with significant effect modification by race/ethnicity, compared with girls from intact households. The associations were strongest among Black girls (adjusted hazard ratio [HR]: 1.60, 95% confidence interval [CI]: 1.29,1.98; HR: 1.42, 95%CI: 1.15,1.77 for thelarche and pubarche, respectively). There were no significant associations among Asian/Pacific Islanders. Girls who lived in non-intact households before age 2 years were also at increased risk for earlier menarche, but without race/ethnic interaction. Adjustment for prepubertal obesity did not change these associations. Associations between living in non-intact households after age 2 years and early puberty were weaker but still significant. CONCLUSIONS: Exposure to a non-intact household early in life may increase the risk of early puberty in girls. Future psychosocial interventions focused on improving family cohesiveness and efforts to reduce childhood stress among families that are non-intact may mitigate these negative associations, thereby preventing future adverse health effects of early puberty and health disparities.

Earlier age of sex and substance use initiation is associated with unique hormone profiles during social evaluative threat in Mexican American adolescents.

Latinx adolescents are at a disproportional risk for poor sexual and reproductive health outcomes (STIs, adolescent pregnancy) compared to other ethnic groups. They also report high rates of alcohol and drug use that are similar to non-Hispanic White youth. The hormonal underpinnings of the emergence of sex and substance use behaviors among Latinx adolescents remain understudied however. Pubertal shifts in motivation and reward-seeking in social situations are closely tied to the emergence of risky sexual and substance use behaviors. The experience of developing earlier or later than same age peers may increase stress (cortisol) reactivity during social evaluative situations leading to more risky behavior. Further, testosterone can be responsive to social evaluative threat (SET) and is linked to status-seeking behavior, including risk-taking. The current study sought to unravel the complex relationship between cortisol and testosterone responsivity to social evaluative threat, pubertal status, and the emergence of sex and drug use among US-born Mexican-origin youth growing up in an agricultural community. Mexican American 14-year olds (N = 234, 54% female) from the Center for Health Assessment of Mothers and Children (CHAMACOS) participated in the Trier Social Stress Test. Cortisol and testosterone were assayed from saliva. At 16, youth reported on age at vaginal and oral sex initiation, and alcohol and marijuana use initiation. Hierarchical regressions examined cortisol and testosterone reactivity, and pubertal status within each sex to predict the onset of these risky behaviors. Results indicated that boys who were less developed than their same-aged peers or with lower testosterone reactivity and elevated cortisol reactivity to the TSST reported the earliest sex and substance use initiation. For girls, higher cortisol reactivity predicted earlier alcohol use initiation, and higher testosterone reactivity predicted earlier oral sex. Our results suggests it is important for health care providers to not overlook Latinx boys who may look younger in discussions about mitigating risk. Latinx girls under increased stress may be more likely to try to self-medicate with alcohol, and potentially other drugs.

Urinary polycyclic aromatic hydrocarbons in relation to anthropometric measures and pubertal development in a cohort of Northern California girls.

BACKGROUND: Polycyclic aromatic hydrocarbons (PAHs) are a class of ubiquitous, environmental chemicals that may have endocrine disrupting capabilities. We investigated whether childhood exposure to PAHs was associated with adiposity and pubertal timing in a longitudinal study of 404 girls enrolled in the Northern California site of the Breast Cancer and the Environment Research Program cohort. METHODS: Baseline urinary samples from girls aged 6-8-years-old were assayed for 2-naphthol, fluorene metabolites, phenanthrene metabolites, 1-hydroxypyrene, and sum of PAH metabolites. Mixed-effects linear models were used to estimate how concentrations of PAH metabolites were related to changes in girl's body mass index (BMI) and waist-to-height ratio from age 7 through 16 years old. Accelerated failure time models were used to estimate age of pubertal onset (Tanner stages 2 or higher for breast and pubic hair development). RESULTS: Higher adiposity measurements among high tertiles of baseline PAH metabolites were evident at age 7 years old and increased thereafter (i.e., BMI for all PAH metabolites, waist-to-height ratio for fluorene and phenanthrene metabolites) or leveled off (i.e., waist-to-height ratio for 2-naphthol, 1-hydroxypyrene, sum of PAHs). Among girls overweight/obese at baseline, median age of breast development onset for high tertiles was 9.1-9.4 years old compared with 10-10.2 years old for low tertiles for all PAH metabolites; in contrast, found no association or slightly later onset of breast development for girls with normal weight at baseline. DISCUSSION: These results suggest that exposure to specific PAHs during childhood may influence adiposity throughout adolescence and effect pubertal timing.

Correction to: Breastfeeding and timing of pubertal onset in girls: a multiethnic population-based prospective cohort study.

Following publication of the original article [1], the authors reported that Table 4 was incorrectly presented. The revised and corrected version is shown below.

Breastfeeding and timing of pubertal onset in girls: a multiethnic population-based prospective cohort study.

BACKGROUND: Early puberty is associated with higher risk of adverse health and behavioral outcomes throughout adolescence and adulthood. US girls are experiencing earlier puberty with substantial racial/ethnic differences. We examined the association between breastfeeding and pubertal timing to identify modifiable risk factors of early puberty and potential sources of racial/ethnic differences in the timing of pubertal development. METHODS: A prospective cohort study of 3331 racially/ethnically diverse girls born at Kaiser Permanente Northern California (KPNC) between 2004 and 06. All data were obtained from KPNC electronic clinical and administrative datasets. Mother-reported duration of breastfeeding was obtained from questionnaires administered at each 'well-baby' check-up exam throughout the baby's first year and categorized as 'Not breastfed', 'Breastfed < 6 months', and 'Breastfed ≥ 6 months'. Pubertal development data used Tanner stages assessed by pediatricians during routine pediatric checkups starting at age 6. Pubertal onset was defined as transition from Tanner Stage 1 to Tanner Stage 2+ for breast (thelarche) and pubic hair (pubarche). Weibull regression models accommodating for left, right, and interval censoring were used in all analyses. Models were adjusted for maternal age, education, race/ethnicity, parity and prepubertal body mass index (BMI). We also examined race/ethnicity as a potential effect modifier of these associations. RESULTS: Not breastfeeding was associated with earlier onset of breast and pubic hair development compared to breastfeeding ≥6 months (adjusted hazard ratio [HR]: 1.25; 95% confidence interval [CI]: 1.07-1.46; HR: 1.24; 95% CI: 1.05-1.46, respectively). Breastfeeding for < 6 months was also associated with the risk of earlier pubic hair development (HR: 1.14; 95% CI: 1.00-1.30, compared to breastfeeding ≥6 months). Inclusion of girls' prepubertal BMI slightly attenuated the association between breastfeeding and timing of breast onset but remained significant. The association between not breastfeeding and early breast development may be stronger among African American girls (HR: 1.92; 95% CI: 1.01-3.66, no breastfeeding vs. ≥6 months) than other racial/ethnic groups. CONCLUSIONS: Breastfeeding is an independent predictor of pubertal onset in girls, and the strength of the association may vary by race/ethnicity. Providing breastfeeding support and lactation education for high risk mothers may help prevent earlier pubertal onset and promote positive health outcomes later in life.

Longitudinal study of age of menarche in association with childhood concentrations of persistent organic pollutants.

BACKGROUND: Age at female puberty is associated with adult morbidities, including breast cancer and diabetes. Hormonally active chemicals are suspected of altering pubertal timing. We examined whether persistent organic pollutants (POPs) are associated with age at menarche in a longitudinal study. METHODS: We analyzed data for females enrolled at age 6-8 years in the Breast Cancer and Environment Research Program from California and Ohio. Participants were followed annually 2004-2013 and provided serum (mean age 7.8 years) for measurement of polychlorinated biphenyl (PCB), organochlorine pesticide (OCP), and polybrominated diphenyl ether (PBDE) concentrations. Age of menarche was assigned based on parental and participant reported dates and ages of menarche. Adjusted hazard ratios (aHRs) for menarchal onset were calculated with Cox proportional regression. Body mass index (BMI), potentially on the causal pathway, was added to parallel analyses. RESULTS: Age of menarche was later with higher summed PCB levels (median 11.9 years in quartile 1 [Q1] versus 12.7 in quartile 4 [Q4]) and OCP levels (12.1 years versus 12.4, respectively). When adjusting for all covariates except BMI, higher POP concentrations were associated with later age at menarche (Q4 versus Q1 aHRs: PBDEs 0.75 [95% CI 0.58, 0.97], PCBs 0.67 [95% CI 0.5, 0.89], and OCPs 0.66 [95% CI 0.50, 0.89]). Additional adjustment for BMI attenuated aHRs; PCB aHR approached the null. CONCLUSION: Findings revealed later onset of menarche with higher concentrations of certain POPs, possibly through an association with BMI. Altered pubertal timing may have long lasting effects on reproductive health and disease risk, so continued attention is important for understanding the biological processes affected by hormonally active chemicals.

Associations of Maternal Gestational Weight Gain and Obesity With the Timing of Pubertal Onset in Daughters.

Early puberty is associated with adverse health outcomes, but little is known regarding early-life determinants influencing pubertal timing. We examined the associations between maternal gestational weight gain (GWG) and the timing of the onset of breast development (thelarche) and pubic hair development (pubarche) in a cohort of 2,070 girls born in a Kaiser Permanente Northern California facility between 2005 and 2006. Using Weibull regression models accommodating interval censoring and adjusting for important confounders, we found that excess GWG was associated with increased risk of early thelarche (hazard ratio (HR) = 1.50, 95% confidence interval (CI): 1.26, 1.78) and early pubarche (HR = 1.35, 95% CI: 1.10, 1.66). Inadequate GWG was associated with early thelarche (HR = 1.36, 95% CI: 1.08, 1.71). The associations between excess or inadequate GWG and risk of earlier thelarche were stronger if mothers were obese before or at the beginning of pregnancy (body mass index ≥30 kg body weight per m height squared) (HR = 2.01, 95% CI: 1.53, 2.63; HR = 2.08, 95% CI: 1.45, 2.98, respectively). Similar associations were found for pubarche outcome. Inclusion of girls' prepubertal body mass index slightly attenuated these associations, but they remained significant. Monitoring of maternal weight before and throughout pregnancy might help prevent early pubertal onset and subsequent negative health outcomes.

Association of Infant Temperament With Subsequent Obesity in Young Children of Mothers With Gestational Diabetes Mellitus.

Importance: Infant temperament is associated with excess weight gain or childhood obesity risk in samples of healthy individuals, although the evidence has been inconsistent. To our knowledge, no prior research has examined this topic among children exposed to gestational diabetes mellitus (GDM) in utero. Objective: To prospectively evaluate infant temperament in association with overweight and obesity status at ages 2 to 5 years among children born to mothers who experienced GDM. Design, Setting, and Participants: This prospective cohort study took place at Kaiser Permanente Northern California medical centers. We studied singleton infants delivered at 35 weeks' gestational age or later to mothers who had been diagnosed with GDM. Data were collected from 2009 to 2016, and data analysis occurred from June 2017 to October 2018. Exposures: The primary exposures in the child's first year were soothability, distress to limitations, and activity aspects of temperament, as assessed by a validated questionnaire. Modifiable covariates in the child's first year included breastfeeding intensity and duration monthly ratio scores, along with the timing of the introduction of sugary beverages and complementary foods. Main Outcomes and Measures: The primary outcome was child overweight and obesity status, assessed at ages 2 to 5 years. Multinomial logistic regression models estimated adjusted odds ratios and 95% CIs for infants whose temperaments were measured at 6 to 9 weeks of age and categorized as elevated (≥75th percentile) or not elevated in the 3 domains. We controlled for nonmodifiable and modifiable covariates across models. Results: A total of 382 mother-infant pairs participted, including 130 infants (34.0%) who were non-Hispanic white, 126 infants (33.0%) who were Hispanic, 96 infants (25.1%) who were Asian, 26 infants (6.8%) who were non-Hispanic black, and 4 infants (1.1%) who were of other races/ethnicities. In descriptive analyses, elevated infant soothability and activity temperaments were associated with the early introduction of 100% fruit juice and/or sugar-sweetened beverages (at ages <6 months) and shorter breastfeeding duration (from 0 to <3 months), while elevated distress to limitations was associated with early introduction of complementary foods (at ages <4 months). Elevated soothability consistently was associated with a higher odds of later childhood obesity, with adjusted odds ratios across models ranging from 2.22 (95% CI, 1.04-4.73) to 2.54 (95% CI, 1.28-5.03). Greater breastfeeding intensity and duration (12-month combined) score was associated with lower odds of obesity, independent of infant temperament and other covariates. Conclusions and Relevance: Among this high-risk population of infants, elevated soothability was associated with early childhood obesity risk, perhaps in part because caregivers use sugary drinks to assuage infants. Soothability temperament may be a novel screening target for early obesity prevention interventions involving responsive feeding and emotion regulation.

Sleep duration in Mexican American children: Do mothers' and fathers' parenting and family practices play a role?

This study examined parenting styles, parenting practices and family practices that may be associated with weeknight sleep duration among 8- to 10-year-old Mexican American (MA) children. This cross-sectional study of MA children used baseline data from a 2-year cohort study of mother-child pairs (n = 308) with additional data on fathers (n = 166). Children's weeknight sleep duration was accelerometer estimated and averaged for 2 weeknights. Parents reported on their parenting styles and practices regarding food and family food-related practices. Multivariable linear regression analysis was used to examine sleep duration with parenting styles and practices, and family practices, and adjusting for child gender and body mass index. Model 1 included mothers' parenting styles and practices; Model 2 included both mothers' and fathers' parenting styles and practices. Children's average sleep duration was 9.5 (SD = 0.8) hr. Mothers who used pressure to encourage their children to eat and those who used food to control behavior had children with longer sleep duration (ß = 0.21, p < 0.01; ß = 0.15, p = 0.03, respectively). Mothers who reported their children ate dinner with the TV on and those who valued eating dinner as a family had children with shorter sleep duration (ß = -0.16, p = 0.01; ß = -0.18, p = 0.01, respectively). Fathers who restricted the amount of food their children ate had children with shorter sleep duration (ß = -0.27, p = 0.01). Mothers' and fathers' feeding practices, the child's eating dinner with the TV on, and valuing family dinners, played a role in children's weeknight sleep duration among Mexican American families. Parental feeding practices and family mealtime contexts may have an effect on children's weeknight sleep duration.