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Introduction: During adolescence, dairy product intake has shown conflicting associations with metabolic syndrome (MetS) components, which are risk factors for cardiovascular disease (CVD). This study aims to investigate the association between plasma fatty acids (FAs) C15:0, C17:0, and t-C16:1n-7, as biomarkers of dairy intake, with MetS and its components in Mexican adolescents. Methods: A sample of 311 participants from the Early Life Exposure in Mexico City to Environmental Toxicants (ELEMENT) cohort was included in this cross-sectional analysis. FA concentrations were measured in plasma as a percentage of total FA. We used quantile regression models stratified by sex to evaluate the association between FA quantiles and MetS components, adjusting for age, socioeconomic status (SES), sedentary behavior, BMI z-score, pubertal status, and energy intake. Results: We found significant associations between dairy biomarkers and the median of MetS variables. In females, t-C16:1n-7 was associated with a decrease of 2.97 cm in WC (Q4 vs. Q1; 95% CI: −5.79, −0.16). In males, C15:0 was associated with an increase of 5.84 mm/Hg in SBP (Q4 vs. Q1; CI: 1.82, 9.85). For HDL-C, we observed opposite associations by sex. C15:0 in males was associated with decreased HDL-C (Q3 vs. Q1: β = −4.23; 95% CI: −7.98, −0.48), while in females, C15:0 and t-C16:1n-7 were associated with increased HDL-C (Q3 vs. Q1: β = 4.75; 95% CI: 0.68, 8.82 and Q4 vs. Q1: β = 6.54; 95% CI: 2.01, 11.07), respectively. Additionally, in both sexes, different levels of C15:0, C17:0, and t-C16:1n-7 were associated with increased triglycerides (TG). Conclusion: Our results suggest that adolescent dairy intake may be associated in different directions with MetS components and that associations are sex-dependent. [ABSTRACT FROM AUTHOR]

BACKGROUND: Gestational lead (Pb) exposure can adversely affect offspring health through multiple mechanisms, including epigenomic alterations via DNA methylation (5mC) and hydroxymethylation (5hmC), an intermediate in oxidative demethylation. Most current methods do not distinguish between 5mC and 5hmC, limiting insights into their individual roles. OBJECTIVE: Our study sought to identify the association of trimester-specific (T1, T2, T3) prenatal Pb exposure with 5mC and 5hmC levels at multiple cytosine-phosphate-guanine sites within gene regions previously associated with prenatal Pb (HCN2, NINJ2, RAB5A, TPPP) in whole blood leukocytes of children ages 11–18 years of age. METHODS: Participants from the Early Life Exposure in Mexico to Environmental Toxicants (ELEMENT) birth cohorts were selected (n= 144) for pyrosequencing analysis following oxidative or standard sodium bisulfite treatment. This workflow directly quantifies total methylation (5mC+5hmC) and 5mC only; 5hmC is estimated by subtraction. RESULTS: Participants were 51% male, and mean maternal blood lead levels (BLL) were 6.43 ± 5.16 μg/dL in Trimester 1 (T1), 5.66 ± 5.21 μg/dL in Trimester 2 (T2), and 5.86 ± 4.34 μg/dL in Trimester 3 (T3). In addition, 5hmC levels were calculated for HCN2 (mean ± standard deviation(SD), 2.08 ± 4.18%), NINJ2 (G/C: 2.01 ± 5.95; GG: 0.90 ± 3.97), RAB5A (0.66 ± 0.80%), and TPPP (1.11 ± 6.67%). Furthermore, 5mC levels were measured in HCN2 (81.3±9.63%), NINJ2 (heterozygotes: 38.6±7.39%; GG homozygotes: 67.3±9.83%), RAB5A (1.41 ± 1.21%), and TPPP (92.5±8.03%). Several significant associations between BLLs and 5mC/5hmC were identified: T1 BLLs with 5mC in HCN2 (ß= -0.37, 𝑝= 0.03) and 5hmC in NINJ2 (ß= 0.49, 𝑝= 0.003); T2 BLLs with 5mC in HCN2 (ß= 0.37, 𝑝= 0.03) and 5hmC in NINJ2 (ß= 0.27, 𝑝= 0.008); and T3 BLLs with 5mC in HCN2 (ß= 0.50, 𝑝= 0.01) and NINJ2 (ß= -0.35, 𝑝= 0.004) and 5hmC in NINJ2 (ß= 0.45, 𝑝< 0.001). NINJ2 5mC was negatively correlated with gene expression (Pearson 푟 = -0.5, 𝑝-value = 0.005), whereas 5hmC was positively correlated (푟 = 0.4, 𝑝-value = 0.04). DISCUSSION: These findings suggest there is variable 5hmC in human whole blood and that prenatal Pb exposure is associated with gene-specific 5mC and 5hmC levels at adolescence, providing evidence to consider 5hmC as a regulatory mechanism that is responsive to environmental exposures. [ABSTRACT FROM AUTHOR]

Summary: Objectives: To evaluate whether childhood emotional and behavioral characteristics are associated with soda intake. Methods: The study population included 391 Mexico City adolescents enrolled in a birth cohort study. When children were between 6 and 12 years of age, the Behavioral Assessment System for Children (BASC)‐2 was administered. Nondiet soda intake was measured concurrently and again when participants were of peripubertal ages via food frequency questionnaire. Linear regression models were run with soda mL/day (cross‐sectional and change in soda over time) as the outcome and BASC composite scores as predictors (in separate models), adjusting for confounders. Results: At baseline, children were 8.3 (SD 1.3) years (49% males). Three scales out of 18 examined had statistically significant associations. Parent‐reported adaptive skills were inversely associated with concurrent soda intake (β = −2.29 with 95% CI −4.27 to −0.31). Parent‐reported internalizing problems (higher = more problems) were related to higher change in soda intake from childhood to adolescence (β = 5.83 with 95% CI 0.98‐10.68; N = 191). Self‐reported school problems were associated with a higher change in soda intake over time (β = 9.46 with 95% CI 2.10‐16.82; N = 122). Conclusions: Parent‐ and self‐reported emotional and behavioral difficulties in childhood were associated with soda consumption and changes in soda consumption over time. [ABSTRACT FROM AUTHOR]

Objectives To evaluate whether age at menarche and time to menstrual regularity were related to cardio-metabolic risk factors in Mexican women. Methods The study population comprised 54,921 women from the 2008-2010 wave of the Mexican Teacher's Cohort. A modified Poisson approach was used; exposures were age at menarche and time to menstrual regularity (< 1 year vs. ≥1 year), and outcomes were prevalent obesity, type 2 diabetes, high blood pressure, and high cholesterol. Results Mean (SD) age of women was 42.1 (7.6) years, and mean (SD) menarcheal age was 12.5 (1.5) years. Compared to women with menarche age 13 years, those with menarche < 9 years had a 65% (95% CI 43-90%); 27% (95% CI 4-55%); and 23% (95% CI 1-49%) higher prevalence of obesity, high blood pressure, and high cholesterol, respectively. For diabetes, there was a U-shaped association; compared to menarche age 13 years, those with menarche < 9 years had an 89% higher prevalence of diabetes (95% CI 39-156%), and those with menarche ≥ 17 years had a 65% higher prevalence (95% CI 16-134%). Among women with regular cycles (n = 43,113), a longer time to menstrual regularity was associated with diabetes (PR = 1.11 with 95% CI 1.02-1.22), high blood pressure (PR = 1.11 with 95% CI 1.06-1.17), and high cholesterol (PR = 1.09 with 95% CI 1.04-1.14). Conclusions for practice Mexican women with earlier and later ages at menarche and/or longer time to menstrual regularity may have higher risk of cardio-metabolic disease in adulthood. [ABSTRACT FROM AUTHOR]

Background: High intake of added sugar and sodium is a public health concern for preschool-aged children living in the US. Externalizing behavior may predict higher consumption of added sugar and/or sodium; however, previous studies have mostly been cross-sectional. The aim was to evaluate whether externalizing behavior is prospectively related to added sugar and intake in a sex-specific manner among preschoolers. Methods: This was a secondary analysis of 524 preschool children (48% male) from Michigan who participated in an obesity prevention trial that occurred during one school year from 2011 to 2015. Teacher-assessed externalizing behaviors and three 24-h dietary recalls were completed at baseline and follow-up. We used linear mixed effects regression to evaluate the association between externalizing behavior at baseline and added sugar (% of total Calories) and sodium intake (mg/1000 Calories) at follow-up. In adjusted analysis, we included baseline income-to-needs ratio, child race/ethnicity, and baseline overweight status. All models were adjusted for total energy intake and accounted for clustering by classroom. Results: Baseline externalizing behavior was positively associated with added sugar intake at follow-up among boys; after adjustment for confounders, every 5 points lower externalizing T-score (corresponding to higher externalizing behavior) was associated with a 0.6 higher percentage of added sugar per total Calories (95% CI 0.2 to 1.1; P value = 0.004). In contrast, girls with higher levels of externalizing behavior had lower consumption of added sugars; after confounder adjustment, every 5 points lower externalizing T-score was related to 0.6 lower percentage intake (95% CI -1.0 to -0.1; P value = 0.01). Baseline externalizing behavior was inversely associated with sodium intake at follow-up among boys. After potential confounder adjustment, for every 5 points lower externalizing behavior T-score, there was a 22 mg/1000 Cal lower sodium intake (95% CI -45 to 1; P value = 0.06). In contrast, after adjustment for confounders, every 5 points lower externalizing T-score among girls was related to 24 mg/1000 Cal higher sodium intake (95% CI 1 to 46; P value = 0.04). Conclusions: Externalizing behavior among preschool-aged children was prospectively related to added sugar and sodium intake in a sex-dependent manner. [ABSTRACT FROM AUTHOR]

Introduction Estrogen inhibits lactation and bisphenol A (BPA) is a high production environmental estrogen. We hypothesize an inhibitory effect of BPA on lactation and aim to analyze the association between third trimester pregnancy urinary BPA and breastfeeding rates 1 month postpartum. Methods Odds ratios (OR) and 95 % confidence intervals (95 % CI) of breastfeeding and perceived insufficient milk supply (PIM) in relation to maternal peripartum urinary BPA concentrations were calculated in 216 mothers. Results 97.2 % of mothers in the lowest BPA tertile were breastfeeding at 1 month postpartum, compared to 89.9 % in highest ( p = 0.01). Adjusted ORs (95 % CI) for not breastfeeding at 1 month were 1.9 (0.3, 10.7) and 4.3 (0.8, 21.6) for second and third BPA tertiles, respectively, compared to the lowest ( p = 0.06, trend). 4.2 % reported PIM in the lowest BPA tertile, compared to 8.7 % in the highest ( p = 0.03). Adjusted ORs (95 % CI) for PIM were 1.8 (0.4, 7.7) and 2.2 (0.5, 9.5), for the second and third BPA tertiles, respectively, compared to the lowest ( p = 0.29, trend). Discussion These results suggest an association between maternal BPA exposure and decreased breastfeeding. [ABSTRACT FROM AUTHOR]

BACKGROUND: Previous studies suggest that blood lead levels are positively associated with attention deficit/hyperactivity disorder (ADHD) and ADHD-symptoms in children. However, the associations between lead exposure and ADHD subtypes are inconsistent and understudied. OBJECTIVE: The objective of this study was to explore the association of low-level concurrent lead exposure with subtypes of ADHD symptoms in 578 Mexican children 6-13 years of age. METHODS: We measured concurrent blood lead levels using inductively coupled plasma mass spectrometry (ICPMS). We administered the Conners' Rating Scales-Revised (CRS-R) to mothers to evaluate their children's ADHD symptoms. We used imputation to fill missing values in blood lead levels and used segmented regression models adjusted for relevant covariates to model the nonlinear relationship between blood lead and ADHD symptoms. RESULTS: Mean ± SD blood lead levels were 3.4 ± 2.9 µg/dL. In adjusted models, a 1-µg/dL increase in blood lead was positively associated with Hyperactivity and Restless-Impulsivity scores on the CRS-R scale and Hyperactivity-Impulsivity scores on the CRS-R scale of the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, but only in children with blood lead level ≤ 5 µg/dL. Blood lead was not associated with Inattentive symptoms or overall ADHD behavior. CONCLUSIONS: In this population of Mexican children, current blood lead level among children with low exposure (≤ 5 µg/dL) was positively associated with hyperactive/impulsive behaviors, but not with inattentiveness. These results add to the existing evidence of lead-associated neurodevelopmental deficits at low levels of exposure. CITATION: Huang S, Hu H, Sánchez BN, Peterson KE, Ettinger AS, Lamadrid-Figueroa H, Schnaas L, Mercado-García A, Wright RO, Basu N, Cantonwine DE, Hernández-Avila M, Téllez-Rojo MM. 2016. Childhood blood lead levels and symptoms of attention deficit hyperactivity disorder (ADHD): a cross-sectional study of Mexican children. Environ Health Perspect 124:868-874; http://dx.doi.org/10.1289/ehp.1510067 [ABSTRACT FROM AUTHOR]

Background: Being a last-born child and having a sister have been associated with higher body mass index (BMI). Encouragement to eat that overrides children's self-regulation has been reported to increase the risk of obesogenic eating behaviors. This study sought to test the hypothesis that encouragement to eat during mealtime from older siblings and sisters mediates associations of being last-born or having a sister with higher BMI. Methods: Children aged 4-8 years (n = 75) were videotaped while eating a routine evening meal at home with one sibling present. Encouragement to eat (defined as direct prompts to eat or general positive statements about food) delivered to the index child (IC) from the sibling was coded from the videotape. Path analysis was used to examine associations between IC's birth order, sibling's sex, encouragement counts, and IC's measured BMI z-score (BMIz). Results: Being the younger sibling in the sibling dyad was associated with the IC receiving more encouragements to eat from the sibling (β: 0.93, 95 % confidence interval (CI): 0.59, 1.26, p < 0.0001). The IC having a sister compared with a brother was not associated with the IC receiving more encouragements to eat from the sibling (β: 0.18, 95 % CI: -0.09, 0.47, p = 0.20). The IC receiving more encouragements to eat from the sibling was associated with lower IC BMIz (β: -0.06, 95 % CI: -0.12, 0.00, p = 0.05). Conclusions: Children were more likely to receive encouragements to eat from older siblings than younger siblings. Being the recipient of encouragements to eat from a sibling was associated with lower, not higher, child BMIz, which may reflect sibling modeling of maternal behavior. Future longitudinal studies are needed to examine whether encouragements to eat from siblings lead to increase in BMI over time. Encouragements from siblings may be a novel intervention target for obesity prevention. [ABSTRACT FROM AUTHOR]

Multivitamin supplementation has been shown to reduce the risk of low birthweight. This effect could be mediated through gestational weight gain. However, the effect of multivitamin supplementation on weight gain during pregnancy has not been fully studied. The objective of this study was to examine the effects of multivitamins on pregnancy weight gain. We enrolled 8468 HIV-negative women from Dar es Salaam, Tanzania, in a randomised, placebo-controlled trial of multivitamins on birth outcomes. Women were randomly assigned to receive either a daily oral dose of multivitamin tablets or a placebo and were weighed every 4 weeks from enrolment until the last visit before delivery. Intent-to-treat analyses were carried out to examine the effects of multivitamins on pregnancy weight gain. Multivariate linear and binomial regression models with the log-link function were used to examine the association of weight gain during pregnancy to birthweight. The overall total weight gain was 253 g ( SE: 69, P: 0.0003) more, while the overall 4 weekly weight gain was 59 g greater ( SE: 18, P: 0.005) among women who received multivitamins compared to placebo. Women in the lowest quartile of gestational weight gain had babies with an average birthweight of 3030 g ( SD: 524), while women in the highest quartile had babies weighing 3246 g ( SD: 486), on average. Prenatal multivitamin supplements increased gestational weight gain, which was a significant predictor of birthweight. [ABSTRACT FROM AUTHOR]

Background: Maternal depression may influence feeding practices important in determining child eating behaviors and weight. However, the association between maternal depressive symptoms and feeding practices has been inconsistent, and most prior studies used self-report questionnaires alone to characterize feeding. The purpose of this study was to identify feeding practices associated with maternal depressive symptoms using multiple methodologies, and to test the hypothesis that maternal depressive symptoms are associated with less responsive feeding practices. Methods: In this cross-sectional, observational study, participants (n = 295) included low-income mothers and their 4- to 8-year-old children. Maternal feeding practices were assessed via interviewer-administered questionnaires, semi-structured narrative interviews, and videotaped observations in home and laboratory settings. Maternal depressive symptoms were measured using the Center for Epidemiologic Studies-Depression scale (CES-D). Regression analyses examined associations between elevated depressive symptoms (CES-D score ≥16) and measures of maternal feeding practices, adjusting for: child sex, food fussiness, number of older siblings; and maternal age, body mass index (BMI), education, race/ethnicity, single parent status, perceived child weight, and concern about child weight. Results: Thirty-one percent of mothers reported depressive symptoms above the screening cutoff. Mothers with elevated depressive symptoms reported more pressuring of children to eat (ß = 0.29; 95% Confidence Interval (CI): 0.03, 0.54) and more overall demandingness (ß = 0.16; 95% CI: 0.03, 0.29), and expressed lower authority in child feeding during semi-structured narrative interview (Odds Ratio (OR) for low authority: 2.82; 95% CI: 1.55, 5.12). In homes of mothers with elevated depressive symptoms, the television was more likely audible during meals (OR: 1.91; 95% CI: 1.05, 3.48) and mothers were less likely to eat with children (OR: 0.48; 95% CI: 0.27, 0.85). There were no associations between maternal depressive symptoms and encouragement or discouragement of food in laboratory eating interactions. Conclusions: Mothers with elevated depressive symptoms demonstrated less responsive feeding practices than mothers with lower levels of depressive symptoms. These results suggest that screening for maternal depressive symptoms may be useful when counseling on healthy child feeding practices. Given inconsistencies across methodologies, future research should include multiple methods of characterizing feeding practices and direct comparisons of different methodologies. [ABSTRACT FROM AUTHOR]

ABSTRACT Purpose To use the lifecourse framework to examine the association between duration of breastfeeding and risk of developing bulimic behaviors or a diagnosed eating disorder. Method Questionnaires were sent every 12-24 months between 1996 and 2005 to 6,436 females and 5,756 males in the Growing Up Today Study, who were 9-14 years at baseline. Duration of breastfeeding was reported by the participants' mothers in 1997. We used generalized estimating equations to estimate the association of breastfeeding with purging, binge eating, engaging in bulimic behaviors, and having a diagnosed eating disorder. Results Compared to girls who were breastfed for more than 9 months, those who were breastfed for less than 4 months did not have a significantly different prevalence of purging, binge eating, bulimic behaviors, and self-reported history of diagnosed eating disorders. Adjusting for gestational age/birthweight, age, age at menarche, maternal history of an eating disorder, and maternal body mass index, short duration of breastfeeding was not associated with any outcome among the girls [adjusted odds ratios (AOR) ranged from 0.8 to 1.1]. Among the boys, the results showed no significant associations between duration of breastfeeding and purging, binge eating, and self-reported history of diagnosed eating disorder. However, there was a suggestion that boys who had been breastfed for less than 4 months were at a higher risk of engaging in bulimic behaviors [AOR: 1.5, 95% confidence interval (CI), 1.0-2.3]. Discussion No association was found between duration of breastfeeding and risk of developing bulimic behaviors or a diagnosed eating disorder among girls or boys with the one exception of longer duration of breastfeeding associated with fewer bulimic behaviors in boys. Although there are many benefits to breastfeeding, our data suggest that breastfeeding does not offer any protection against binge eating or purging, nor does it present harmful effects. © 2013 Wiley Periodicals, Inc. (Int J Eat Disord 2013; 46:834-840) [ABSTRACT FROM AUTHOR]

Background: Few studies have evaluated the association of diet and weight status with head and neck cancer outcomes. Objective: The purpose of this study was to determine whether pretreatment dietary patterns and weight status are associated with head and neck cancer prognosis. Design: This was a longitudinal study of 542 patients with newly diagnosed head and neck cancer who completed food-frequency questionnaires and health surveys before treatment. Clinical data were abstracted from medical records and the Social Security Death Index. Dietary patterns were identified by using principal component analysis. Cox proportional hazard models were used to examine the association of derived dietary patterns (fit by quintiles of exposure) and weight status with time to recurrence and survival, with control for covariates. Results: During the study period, there were 229 deaths and 184 recurrences. Two dietary patterns were identified: a whole-foods pattern (characterized by high intakes of vegetables, fruit, fish, poultry, and whole grains) and a Western pattern (characterized by high intakes of red and processed meats, refined grains, potatoes, and French fries). In multivariable analyses, significantly fewer deaths were observed in subjects most adherent to the whole-foods pattern (HR: 0.56; 95% CI: 0.34, 0.92; P-trend = 0.01). Subjects classified as overweight or obese had significantly fewer deaths (HR: 0.65; 95% CI: 0.49, 0.85; P = 0.001) and recurrences (HR: 0.70; 95% CI: 0.52, 0.95; P = 0.02) than did normal-weight or underweight subjects. Conclusion: Consumption of a diet rich in vegetables, fruit, fish, poultry, and whole grains and being overweight before diagnosis with head and neck cancer are associated with a better prognosis. [ABSTRACT FROM AUTHOR]

BACKGROUND: Dietary and physical activity (PA) behaviors can predict disordered weight control behaviors (DWCB) among youth. This study examines dietary and PA correlates of DWCB and differences by race/ethnicity and weight status in a diverse sample of youth. METHODS: Self-reported data on dietary weight management behaviors, strengthening/toning exercises, moderate-to-vigorous physical activity, and DWCB (vomiting, taking laxatives, and/or taking diet pills without a prescription) were obtained from 15,260 sixth to eighth graders in 47 middle schools participating in the Massachusetts Healthy Choices Study at baseline (2005). Generalized estimating equations were used to estimate odds of DWCB associated with dietary and PA behaviors and to examine for differences by race/ethnicity and weight status, adjusting for covariates and clustering of individuals within schools. RESULTS: Disordered weight control behaviors were reported by 3.6% of girls and 3.1% of boys. Youth who engaged in strengthening/toning exercises 7 days per week versus 0-3 days per week had increased odds of DWCB (girls odds ratio [OR] = 1.9; 95% confidence interval [CI] = 1.3 − 3.0; boys OR = 1.5; 95% CI = 1.0 − 2.2). Dietary weight management behaviors were associated with increased odds of DWCB (girls OR = 1.2; 95% CI = 1.1 − 1.3; boys OR = 1.3; 95% CI = 1.2 − 1.4) for each additional behavior. These associations did not differ by race/ethnicity or weight status. CONCLUSIONS: Persons promoting healthy dietary and PA behaviors among youth should consider the co-occurrence of strengthening/toning and dietary weight management behaviors with DWCB and the consistency in these associations across racial/ethnic and weight status groups. [ABSTRACT FROM AUTHOR]

Background: Despite the benefits of exclusive breastfeeding (EBF), exposure to HIV from breast milk has relegated EBF to an option only when formula feeding is not affordable, feasible, safe, and sustainable. Mixed feeding remains the norm in sub-Saharan Africa. Objective: We evaluated whether the duration of EBF was associated with mortality and HIV infection in children followed to ≤5 y of age. Methods: A total of 690 mother-infant pairs from the Trial of Vitamins with information on infant feeding, HIV status, and at least one visit in the first year were included in the analysis. The duration of EBF was defined in months as a time-varying covariate at each follow-up visit. Associations of the duration of EBF with mortality, HIV infection, and HIV infection or death were estimated by using Cox proportional hazards models and Kaplan-Meier survival curves. Results: A 1-mo increase in EBF was associated with a 49% reduction in early infant mortality in the first 6 mo of life (RR: 0.51 ; 95% CI: 0.28, 0.93) and a nonsignificant 15% reduction in risk of HIV infection or death (RR: 0.85; 95% CI: 0.71, 1.01; P = 0.07) over the first 5 y of life. EBF was not associated with HIV infection (RR: 0.93; 95% CI: 0.76, 1.15). Conclusion: Longer EBF by HIV-positive mothers was associated with reduced mortality in the first 6 mo of life without increased HIV infection, which makes EBF the best option for women who cannot sustain exclusive formula feeding. This trial was registered at clinicaltrials.gov as NCT00197743. [ABSTRACT FROM AUTHOR]

Background: Cumulative prenatal lead exposure, as measured by maternal bone lead burden, has been associated with smaller weight of offspring at birth and 1 month of age, but no study has examined whether this effect persists into early childhood. Objective: We investigated the association of perinatal maternal bone lead, a biomarker of cumulative prenatal lead exposure, with children's attained weight over time from birth to 5 years of age. Methods: Children were weighed at birth and at several intervals up until 60 months. Maternal tibia and patella lead were measured at 1 month postpartum using in vivo K-shell X-ray fluorescence. We used varying coefficient models with random effects to assess the association of maternal bone lead with weight trajectories of 522 boys and 477 girls born between 1994 and 2005 in Mexico City. Results: After controlling for breast-feeding duration, maternal anthropometry, and socio- demographic characteristics, a 1-SD increase in maternal patella lead (micrograms per gram) was associated with a 130.9--g decrease in weight [95% confidence interval (CI), -227.4 to -34.4 g] among females and a 13.0--g nonsignificant increase in weight among males (95% CI, -73.7 to 99.9 g) at 5 years of age. These associations were similar after controlling for concurrent blood lead levels between birth and 5 years. Conclusions: Maternal bone lead was associated with lower weight over time among female but not male children up to 5 years of age. Given that the association was evident for patellar but not tibial lead levels, and was limited to females, results need to be confirmed in other studies. [ABSTRACT FROM AUTHOR]

This paper examines predictors of breastfeeding cessation among a cohort of human immunodeficiency virus (HIV)-infected women. This was a prospective follow-up study of HIV-infected women who participated in a randomized micronutrient supplementation trial conducted in Dar es Salaam, Tanzania. 795 HIV-infected Tanzanian women with singleton newborns were utilized from the cohort for this analysis. The proportion of women breastfeeding declined from 95% at 12 months to 11% at 24 months. The multivariate analysis showed breastfeeding cessation was significantly associated with increasing calendar year of delivery from 1995 to 1997 [risk ratio (RR), 1.36; 95% confidence interval (CI) 1.13-1.63], having a new pregnancy (RR 1.33; 95% CI 1.10-1.61), overweight [body mass index (BMI) ≥25 kg m; RR 1.37; 95% CI 1.07-1.75], underweight (BMI <18.5 kg m; RR 1.29; 95% CI 1.00-1.65), introduction of cow's milk at infant's age of 4 months (RR 1.30; 95% CI 1.04-1.63). Material and social support was associated with decreased likelihood of cessation (RR 0.83; 95% CI 0.68-1.02). Demographic, health and nutritional factors among women and infants are associated with decisions by HIV-infected women to cease breastfeeding. The impact of breastfeeding counselling programs for HIV-infected African women should consider individual maternal, social and health contexts. [ABSTRACT FROM AUTHOR]

Introduction: Epigenetic aging, a marker of biological aging measured by DNA methylation, may be affected by behaviors, including sleep and physical activity. However, investigations of physical activity and sleep with epigenetic aging among pediatric populations are scant and have not accounted for correlated behaviors. Methods: The study population included 472 Mexico City adolescents (52% female). Blood collection and 7-d wrist actigraphy (Actigraph GTX-BT) occurred during a follow-up visit when participants were 14.5 (2.09) yr. Leukocyte DNA methylation was measured with the Infinium MethylationEPIC array after bisulfite conversion, and nine epigenetic clocks were calculated. Sleep versus wake time was identified through a pruned dynamic programing algorithm, and physical activity was processed with Chandler cutoffs. Kmeans clustering was used to select actigraphy-assessed physical activity and sleep behavior clusters. Linear regression analyses were used to evaluate adjusted associations between the clusters and epigenetic aging. Results: There were three unique clusters: “Short sleep/high sedentary behavior,” “Adequate sleep duration and late sleep timing/low moderate or vigorous physical activity (MVPA),” and “Adequate sleep duration/high MVPA.” Compared with the “Adequate duration/high MVPA,” adolescents with “Adequate duration and late sleep timing/low MVPA” had more accelerated aging for the GrimAge clock (β = 0.63; 95% confidence interval, 0.07–1.19). In pubertal-stratified analyses, more mature adolescents in the “Adequate sleep duration and late sleep timing/low MVPA group” had accelerated epigenetic aging. In contrast, females in the “Short sleep/high sedentary” group had decelerated epigenetic aging for the Wu pediatric clock. Conclusions: Associations between behavior clusters and epigenetic aging varied by pubertal status and sex. Contrary results in the Wu clock suggest the need for future research on pediatric-specific clocks. [ABSTRACT FROM AUTHOR]

Children who frequently experience encouragement or pressure to eat are more likely to exhibit less favorable eating behaviors and dietary outcomes. Siblings can encourage or pressure each other to eat during mealtimes, but the role of mothers in shaping sibling mealtime interactions is not understood. The objective of this study was to examine the association between the behavior of mothers and siblings during mealtimes. The associations of maternal presence and maternal engagement with children during mealtimes with encouragements to eat delivered by the child to his/her sibling were examined. Children aged 4-8years (n=73) were videotaped while eating a routine evening meal at home with one sibling present. Encouragement to eat delivered by the index child to the sibling, maternal presence, and non-food-related and food-related maternal engagement were coded from the videotapes. Poisson regression showed that maternal presence was associated with fewer encouragements to eat from the index child to the sibling (rate ratio (RR): 0.40, 95% confidence interval (CI): 0.26, 0.62). Each type of maternal engagement was independently associated with the number of encouragements to eat from the index child to the sibling: maternal engagement that was not food-related was associated with fewer encouragements to eat (RR: 0.62, 95% CI: 0.53, 0.73), while maternal engagement that was food-related was associated with more encouragements to eat (RR: 1.49, 95% CI: 1.22, 1.81). Future studies may explore how sibling interactions may mediate links between maternal behavior during mealtimes and children's health-related outcomes. [ABSTRACT FROM AUTHOR]

Supplemental digital content is available in the text. Introduction/Purpose: Limited studies have examined the association of physical activity with reproductive hormones, DNA methylation, and pubertal status among adolescents. Methods: Among 248 boys and 271 girls, we estimated daily physical activity levels based on 7 d of wrist-worn accelerometer data. We used an isotemporal substitution paradigm and sex-stratified regression models to examine the association of physical activity levels with 1) testosterone, cortisol, progesterone, and androstenedione concentrations; 2) DNA methylation of long interspersed nucleotide (LINE-1) repeats and the genes H19 , hydroxysteroid (11-Beta) dehydrogenase 2 (HSD11B2), and peroxisome proliferator-activated receptor alpha (PPARA) from blood leukocytes; and 3) Tanner stages, adjusted for age, BMI, and socioeconomic status. Results: In boys, substituting 30 min of moderate physical activity for 30 min of sedentary behavior per day was associated with 29% (−49%, 0%) of lower testosterone and 29% (4%, 61%) of higher progesterone. Substituting 30 min of light physical activity for sedentary behavior was associated with 13% (−22%, −2%) of lower progesterone. Among girls, 30 min of additional sedentary behavior was associated with 8% (−15%, 0%) of lower testosterone and 24% (8%, 42%) of higher progesterone concentrations. Substituting 30 min of moderate physical activity for sedentary behavior was associated with 15% (0%, 31%) of higher cortisol, whereas substituting the same amount of light physical activity for sedentary behavior was associated with 22% (−39%, 0%) of lower progesterone. Substituting 30 min of vigorous physical activity for sedentary behavior per day was associated with almost six times higher levels (5.83, 95% confidence interval = 1.79–9.86) of HSD11B2 methylation in boys. Conclusions: Accelerometer-measured daily physical activity was associated with reproductive hormones and HSD11B2 DNA methylation, differed by sex and activity intensity levels. [ABSTRACT FROM AUTHOR]

Childhood diet has been implicated in timing of sexual maturation. A key limitation of published studies is the focus on individual foods rather than patterns. We hypothesized that dietary patterns characterized by fruits and vegetables during early childhood (age 3 years) would be associated with delayed pubertal timing, whereas energy-dense and meat-based dietary patterns would relate to earlier puberty. The study population included 496 participants of a Mexico City birth cohort. The exposures of interest were dietary patterns derived from principal component analysis of dietary data collected via a semiquantitative food frequency questionnaire when the children were 3 years of age, and the outcomes were physician-assessed Tanner stages for pubic hair, breast (girls), genitalia, and testicular volume (boys) between 9 and 18 years, and initiation of menarche (girls). In regression analyses, we estimated adjusted hazard ratios and 95% confidence intervals for having reached Tanner stage ≥4 or initiation of menarche in girls and testicular volume ≥15 mL in boys. Among girls, those in the highest vs lowest tertile of vegetables and lean proteins pattern had a 35% (95% confidence interval 3%-67%) lower adjusted probability of having reached breast stage ≥4. Among boys, the processed meats and refined grain pattern score was associated with more advanced testicular development (adjusted hazard ratio = 3.58 [0.62-6.53]). Early childhood dietary patterns may play a role in the tempo of sexual maturation, which could ultimately carry implications for chronic disease susceptibility. [ABSTRACT FROM AUTHOR]