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Objective: The purpose of this study was to investigate the association between maternal employment and infant BMI z score., Methods: Longitudinal data from 520 mother-infant dyads participating in the Nurture Study, an observational cohort in the southeastern United States, were leveraged. Women were categorized as employed or nonemployed at 3, 6, 9, and 12 months, and measured anthropometrics were used to calculate infants' BMI z scores at the corresponding time points. BMI z score was defined using the World Health Organization standard. Household income was an effect modifier. Therefore, income-stratified (≤$40,000/y vs. >$40,000/y) linear regression models, with individual fixed effects, were used to examine associations between change in maternal employment status and BMI z scores among infants aged 3 to 12 months. Fixed effects controlled for time-invariant confounders (race/ethnicity, infant gender). This study also controlled for marital status and infant age., Results: More women from higher-income (68.4%) versus lower-income households (52.6%) were employed. Among lower-income households, change from nonemployment to employment was associated with higher infant BMI z scores (β = 0.12; 95% CI: -0.01 to 0.25, P = 0.07). Among higher-income households, change in maternal employment status was associated with lower infant BMI z scores (β = -0.72; 95% CI: -1.17 to -0.27, P = 0.02)., Conclusions: Maternal employment was related to infant adiposity. The direction of the association varied by household-level income., (© 2020 The Obesity Society.)

Background: DNA methylation has been shown to be associated with adiposity in adulthood. However, whether similar DNA methylation patterns are associated with childhood and adolescent body mass index (BMI) is largely unknown. More insight into this relationship at younger ages may have implications for future prevention of obesity and its related traits., Methods: We examined whether DNA methylation in cord blood and whole blood in childhood and adolescence was associated with BMI in the age range from 2 to 18 years using both cross-sectional and longitudinal models. We performed meta-analyses of epigenome-wide association studies including up to 4133 children from 23 studies. We examined the overlap of findings reported in previous studies in children and adults with those in our analyses and calculated enrichment., Results: DNA methylation at three CpGs (cg05937453, cg25212453, and cg10040131), each in a different age range, was associated with BMI at Bonferroni significance, P < 1.06 × 10 -7 , with a 0.96 standard deviation score (SDS) (standard error (SE) 0.17), 0.32 SDS (SE 0.06), and 0.32 BMI SDS (SE 0.06) higher BMI per 10% increase in methylation, respectively. DNA methylation at nine additional CpGs in the cross-sectional childhood model was associated with BMI at false discovery rate significance. The strength of the associations of DNA methylation at the 187 CpGs previously identified to be associated with adult BMI, increased with advancing age across childhood and adolescence in our analyses. In addition, correlation coefficients between effect estimates for those CpGs in adults and in children and adolescents also increased. Among the top findings for each age range, we observed increasing enrichment for the CpGs that were previously identified in adults (birth P enrichment  = 1; childhood P enrichment  = 2.00 × 10 -4 ; adolescence P enrichment  = 2.10 × 10 -7 )., Conclusions: There were only minimal associations of DNA methylation with childhood and adolescent BMI. With the advancing age of the participants across childhood and adolescence, we observed increasing overlap with altered DNA methylation loci reported in association with adult BMI. These findings may be compatible with the hypothesis that DNA methylation differences are mostly a consequence rather than a cause of obesity.

This study examines pre-pregnancy Body Mass Index (BMI) and gestational weight gain (GWG) in relation to early childhood Attention Deficit Hyperactivity Disorder (ADHD) symptoms and related executive self-regulation behaviors. The analyses sample ( n = 331) included a subsample of participants from a birth cohort recruited from prenatal clinics and hospital facilities from April 2005 to June 2011 in Durham, North Carolina. Pre-pregnancy BMI was calculated from weight at the last menstrual period and height was extracted from medical records. Gestational weight gain was calculated from pre-pregnancy weight and weight measured at the time of delivery. ADHD symptoms and executive self-regulation behaviors were assessed by maternal report (mean age = 3 years). Multivariable regression methods with inverse probability weighting (IPW) were used to evaluate associations accounting for sample selection bias and confounding. Pre-pregnancy BMI at levels ≥35 was positively associated with higher ADHD symptoms and worse executive self-regulation behaviors (inhibitory control and attention). Compared to adequate GWG, less than adequate GWG was related to more ADHD hyperactive-impulsive symptoms, whereas greater than adequate GWG was related to more problematic behaviors related to working memory and planning. The findings support a link between maternal weight and child neurodevelopment. Continued research that help identify biological mechanisms are needed.

Background: Knowledge regarding genetic influences on eating behaviours is expanding; yet less is known regarding contributions of epigenetic variation to appetitive traits and body mass index (BMI) in children., Objective: The purpose of this study was to explore relationships between methylation at differentially methylated regions (DMRs) of imprinted genes (insulin-like growth factor 2/H19 and Delta-like, Drosophila, homolog 1/maternally expressed gene 3) using DNA extracted from umbilical cord blood leucocytes, two genetically influenced appetitive traits (food responsiveness and satiety responsiveness) and BMI., Methods: Data were obtained from participants (N = 317; mean age = 3.6 years; SD = 1.8 years) from the Newborn Epigenetic STudy. Conditional process models were implemented to investigate the associations between DMRs of imprinted genes and BMI, and test whether this association was mediated by appetitive traits and birthweight and moderated by sex., Results: Appetitive traits and birthweight did not mediate the relationship between methylation at DMRs. Increased insulin-like growth factor 2 DMR methylation was associated with higher satiety responsiveness. Higher satiety responsiveness was associated with lower BMI. Associations between methylation at DMRs, appetitive traits and BMI differed by sex., Conclusions: This is one of the first studies to demonstrate associations between epigenetic variation established prior to birth with appetitive traits and BMI in children, providing support for the need to uncover genetic and epigenetic mechanisms for appetitive traits predisposing some individuals to obesity., (© 2018 World Obesity Federation.)

Purpose: It is unclear if exercise and BMI interact to influence prostate cancer (PC) risk. We hypothesized BMI is linked with increased aggressive PC risk but this link will be attenuated with increased exercise., Methods: Men undergoing prostate biopsy completed a questionnaire and metabolic equivalent (MET) hours of exercise was calculated. Of 695 men, 349 had PC; 161 low-grade, and 188 high-grade. We assessed the link between exercise and PC risk, high-grade PC (Gleason 7-10), and low-grade PC (Gleason 2-6) using logistic and multinomial logistic regression. Analysis was stratified by BMI. Link between BMI and PC risk and aggressive PC was similarly tested., Results: On multivariable analysis, there was no link between exercise and PC diagnosis in the entire cohort (p trend = 0.18-0.71) or across BMI groups (p trend = 0.15-0.97). For the entire cohort, higher BMI was linked with increased risk of high-grade PC (OR 1.06, p = 0.008). When stratified by exercise groups, the trend for higher BMI and increased risk of high-grade PC remained (OR 1.03-1.15, p = 0.02-0.66). There were no interactions between exercise and BMI in predicting PC risk (all p ≥ 0.31)., Conclusions: Regardless of exercise, higher BMI was linked with higher risk of aggressive PC, while exercise was unrelated to PC risk. Confirmatory studies are needed.

Objective: To test multiple adiposity measures and prostate cancer (PC) risk in men undergoing prostate biopsy. We hypothesized that body mass index (BMI), body fat, and waist circumference would be highly correlated, and all would be associated with aggressive PC, but not overall risk., Subjects and Methods: A case (483)-control (496) study among men undergoing prostate biopsy from 2007 to 2016 was conducted at the Durham Veterans Affairs Medical Center. Anthropometric and self-reported measurements were taken. Percent body fat was measured. Associations between adiposity measures and PC risk and high-grade PC (Gleason ≥7) were examined using logistic regression., Results: BMI, percent body fat, and waist circumference were highly correlated (ρ ≥ .79) (P < .001). On multivariable analysis, BMI (P = .011) was associated with overall PC risk, but percent body fat (P = .16) and waist circumference (P = .19) were not. However, all adiposity measurements were associated with high-grade disease (P < .001). We found a strong relationship between self-reported and measured weight (ρ = .97) and height (ρ = .92)., Conclusion: BMI, body fat, and waist circumference were all highly correlated and associated with aggressive PC. This study supports the idea that higher adiposity is selectively associated with high-grade PC and reinforces the continued use of self-reported BMI as a measure of obesity in epidemiologic studies of PC., (Published by Elsevier Inc.)

Background: The first 1000 days of life is a critical period of infant growth that has been linked to future adult health. Understanding prenatal factors that contribute to variation in growth during this period could inform successful prevention strategies., Methods: Prenatal and maternal characteristics, including prepregnancy obesity and gestational weight gain were evaluated in relation to weight growth trajectories during the first 24 months of life using the SuperImposition by Translation and Rotation (SITAR) method, which provides estimates of infant size, timing to peak velocity, and growth velocity. The study sample included 704 mother-infant dyads from a multiethnic prebirth cohort from the Southeastern United States. The total number of weight measures was 8670 (median number per child = 14)., Results: Several prenatal and maternal characteristics were linked with infant growth parameters. The primary findings show that compared to women with a prepregnancy BMI between 18 and 24.9, women with a prepregnancy BMI ≥40 had infants that were 8% larger during the first 24 months, a delayed tempo of around 9 days, and a slower velocity. Mothers who had greater than adequate gestational weight gain had infants that were 5% larger even after controlling for prepregnancy BMI and several other covariates., Conclusions: The findings contribute new data on the associations between gestational weight gain and aspects of early growth using the SITAR method, and support a growing consensus in the literature that both prepregnancy BMI and gestational weight gain relate independently to risk for greater postnatal weight growth.

Background: Previous studies suggest an association between obesity and oesophageal (OA) and oesophagogastric junction adenocarcinomas (OGJA). However, these studies have been limited in their ability to assess whether the effects of obesity vary by gender or by the presence of gastro-oesophageal reflux (GERD) symptoms., Methods: Individual participant data from 12 epidemiological studies (8 North American, 3 European and 1 Australian) comprising 1997 OA cases, 1900 OGJA cases and 11 159 control subjects were pooled. Logistic regression was used to estimate study-specific odds ratios (ORs) and 95% confidence intervals (CIs) for the association between body mass index (BMI, kg/m(2)) and the risk of OA and OGJA. Random-effects meta-analysis was used to combine these ORs. We also investigated effect modification and synergistic interaction of BMI with GERD symptoms and gender., Results: The association of OA and OGJA increased directly with increasing BMI (P for trend <0.001). Compared with individuals with a BMI <25, BMI ≥40 was associated with both OA (OR 4.76, 95% CI 2.96-7.66) and OGJA (OR 3.07, 95% CI 1.89-4.99). These associations were similar when stratified by gender and GERD symptoms. There was evidence for synergistic interaction between BMI and GERD symptoms in relation to OA/OGJA risk., Conclusions: These data indicate that BMI is directly associated with OA and OGJA risk in both men and women and in those with and without GERD symptoms. Disentangling the relationship between BMI and GERD will be important for understanding preventive efforts for OA and OGJA.

Objective: To estimate the prevalence of overweight and obesity, and identify factors associated with Body Mass Index (BMI) and waist circumference (WC) among adults residing in an urban township in South Africa. Design: Cross-sectional study. Setting: Khayelitsha, a large black township located in Cape Town. Subjects: 107 males and 530 females, aged ⩾ 18 years. Methods: The prevalence of overweight/obesity (BMI ³ 25 kg/m²) and abdominal obesity (WC ⩾ 94 cm for men and ⩾ 80 cm for women), and their relationship with factors previously found to increase the risk of obesity, such as age, gender, marital status, educational level, employment status, immigrant status from rural to urban, and physical activity level, were assessed using logistic regression analyses. Results: The prevalence of obesity (BMI ³ 30 kg/m²) was 53.4% and 18.7%, and that of abdominal obesity was 71.5% and 23.4%, among women and men respectively. However, more women (21.3%) than men (11.2%) reported walking more than 45 minutes per day. Female gender and being married were associated with a high BMI and large WC. Recent migration was associated with a smaller WC. The level of physical activity was not associated with BMI or WC. Conclusions: These findings suggest that physical activity may play less of a role in obesity control, or that more than 45 minutes of physical activity per day is required to reduce the risk of obesity, especially in women. At least among South African women, obesity control focused on nutritional interventions may be more beneficial than increasing the intensity or duration of physical activity. [ABSTRACT FROM AUTHOR]

Whilst previous studies have reported that higher body-mass index (BMI) increases a woman’s risk of developing ovarian cancer, associations for the different histological subtypes have not been well defined. As the prevalence of obesity has increased dramatically, and classification of ovarian histology has improved in the last decade, we sought to examine the association in a pooled analysis of recent studies participating in the Ovarian Cancer Association Consortium. We evaluated the association between BMI (recent, maximum, and in young adulthood) and ovarian cancer risk using original data from 15 case-control studies (13,548 cases, 17,913 controls). We combined study-specific adjusted odds ratios (ORs) using a random–effects model. We further examined the associations by histological subtype, menopausal status and post-menopausal hormone use. High BMI (all time-points) was associated with increased risk. This was most pronounced for borderline serous (recent BMI: pooled OR=1.24 per 5kg/m2; 95%CI 1.18–1.30), invasive endometrioid (1.17; 1.11–1.23) and invasive mucinous (1.19; 1.06–1.32) tumours. There was no association with serous invasive cancer overall (0.98; 0.94–1.02), but increased risks for low grade serous invasive tumours (1.13, 1.03–1.25) and in pre-menopausal women (1.11; 1.04–1.18). Among post–menopausal women, the associations did not differ between HRT users and non–users. Whilst obesity appears to increase risk of the less common histological subtypes of ovarian cancer, it does not increase risk of high grade invasive serous cancers, and reducing BMI is therefore unlikely to prevent the majority of ovarian cancer deaths. Other modifiable factors must be identified to control this disease.