Early community context, genes, and youth body mass index trajectories: an investigation of gene-community interplay over early life course

Female adolescents' early life stress and body mass index: Differential effects of anger and anxiety in response to rejection

INTRODUCTION

Early life stress is linked to childhood obesity. As children enter adolescence, early life stress may be associated with increased rejection sensitivity, resulting in activation of behavioral and physiological changes that contribute to higher body mass index (BMI). Understanding the potential influence of rejection sensitivity on the association between early life stress and BMI is important to examine in female adolescents. For this secondary data analysis, we hypothesized that female adolescents with greater early life stress and greater rejection sensitivity would exhibit higher BMI-for-age 12 months later.

METHODS

Seventy-eight adolescents (Mage = 13.1 years; 100% female sex; MBMI = 23.2 kg/m2) in the United States completed study procedures from 2012 to 2016. Among these procedures, the Psychosocial Schedule was used to assess cumulative early life stress and the Children's Rejection Sensitivity Questionnaire was used to assess anger and anxiety in response to rejection. Twelve months later, height and weight were measured to derive BMI-for-age.

RESULTS

Higher early life stress was associated with higher BMI-for-age among female adolescents with low rejection-provoked anger (1 SD below the mean). However, this association was not observed among female adolescents with high rejection-provoked anger (1 SD above the mean). Finally, there was no significant interaction between early life stress and rejection-provoked anxiety in predicting BMI-for-age.

CONCLUSIONS

Experiencing early life stress may interact with rejection-provoked anger, but not anxiety, to predict BMI-for-age. Findings inform a developmental perspective of how rejection sensitivity may influence the association between early life stress and early cardiometabolic risk.

ADHD co-morbidities: A review of implication of gene × environment effects with dopamine-related genes

ADHD is a major burden in adulthood, where co-morbid conditions such as depression, substance use disorder and obesity often dominate the clinical picture. ADHD has substantial shared heritability with other mental disorders, contributing to comorbidity. However, environmental risk factors exist but their interaction with genetic makeup, especially in relation to comorbid disorders, remains elusive. This review for the first time summarizes present knowledge on gene x environment (GxE) interactions regarding the dopamine system. Hitherto, mainly candidate (GxE) studies were performed, focusing on the genes DRD4, DAT1 and MAOA. Some evidence suggest that the variable number tandem repeats in DRD4 and MAOA may mediate GxE interactions in ADHD generally, and comorbid conditions specifically. Nevertheless, even for these genes, common variants are bound to suggest risk only in the context of gender and specific environments. For other polymorphisms, evidence is contradictory and less convincing. Particularly lacking are longitudinal studies testing the interaction of well-defined environmental with polygenic risk scores reflecting the dopamine system in its entirety.

Interaction of Neighborhood and Genetic Risk on Waist Circumference in African-American Adults: A Longitudinal Study

BACKGROUND

Understanding determinants of metabolic risk has become a national priority given the increasingly high prevalence rate of this condition among U.S. adults.

PURPOSE

This study's aim was to assess the impact of gene-by-neighborhood social environment interactions on waist circumference (WC) as a primary marker of metabolic risk in underserved African-American adults. Based on a dual-risk model, it was hypothesized that those with the highest genetic risk and who experienced negative neighborhood environment conditions would demonstrate higher WC than those with fewer risk factors.

METHODS

This study utilized a subsample of participants from the Positive Action for Today's Health environmental intervention to improve access and safety for walking in higher-crime neighborhoods, who were willing to provide buccal swab samples for genotyping stress-related genetic pathways. Assessments were conducted with 228 African-American adults at baseline, 12, 18, and 24 months.

RESULTS

Analyses indicated three significant gene-by-environment interactions on WC outcomes within the sympathetic nervous system (SNS) genetic pathway. Two interactions supported the dual-risk hypotheses, including the SNS genetic risk-by-neighborhood social life interaction (b = -0.11, t(618) = -2.02, p = .04), and SNS genetic risk-by-informal social control interaction (b = -0.51, t(618) = -1.95, p = .05) on WC outcomes. These interactions indicated that higher genetic risk and lower social-environmental supports were associated with higher WC. There was also one significant SNS genetic risk-by-neighborhood satisfaction interaction (b = 1.48, t(618) = 2.23, p = .02) on WC that was inconsistent with the dual-risk pattern.

CONCLUSIONS

Findings indicate that neighborhood and genetic factors dually influence metabolic risk and that these relations may be complex and warrant further study.

TRIAL REGISTRATION

NCT01025726.

Exposure to multiple childhood social risk factors and adult body mass index trajectories from ages 20 to 64 years

BACKGROUND

While childhood social risk factors appear to be associated with adult obesity, it is unclear whether exposure to multiple childhood social risk factors is associated with accelerated weight gain during adulthood.

METHODS

We used the Medical Research Council National Survey of Health and Development, a British population-based birth cohort study of participants born in 1946, height and weight were measured by nurses at ages 36, 43, 53 and 60-64 and self-reported at 20 and 26 years. The 9 childhood socioeconomic risk factors and 8 binary childhood psychosocial risk factors were measured, with 13 prospectively measured at age 4 years (or at 7 or 11 years if missing) and 3 were recalled when participants were age 43. Multilevel modelling was used to examine the association between the number of childhood social risk factors and changes in body mass index (BMI) with age.

RESULTS

Increasing exposure to a higher number of childhood socioeconomic risk factors was associated with higher mean BMI across adulthood for both sexes and with a faster increase in BMI from 20 to 64 years, among women but not men. Associations remained after adjustment for adult social class. There was no evidence of an association between exposure to childhood psychosocial risk factors and mean BMI in either sex at any age.

CONCLUSIONS

Strategies for the prevention and management of weight gain across adulthood may need to tailor interventions in consideration of past exposure to multiple socioeconomic disadvantages experienced during childhood.

Early Exposure to Cumulative Social Risk and Trajectories of Body Mass Index in Childhood

BACKGROUND

Childhood social risk has been associated with increased risk of childhood obesity. However, little is known about early exposure of cumulative social risk on BMI percentile (BMIp) trajectories in early childhood.

METHODS

Public data from the Fragile Families and Child Wellbeing Study were analyzed (N = 3809). Maternal reports of experiences of multiple social risk factors were obtained at age 1 and 3 assessments of children. Two cumulative social risk scores were calculated by summing social factors assessed at age 1 and at age 3. Child BMIp was assessed at ages 3, 5, and 9. Linear mixed models were used to examine the effect of cumulative social risk on sex-specific BMIp trajectories.

RESULTS

Compared with girls experiencing low social risk at either age 1 or 3, girls experiencing high social risk (≥ 2 factors) at age 1 or 3 only had higher initial BMIp at age 3 [β₀ = 5.70 (95% confidence interval, CI: 0.15-1.26) and 1.37 (95% CI: -2.25 to 4.99), respectively] and had nonsignificantly greater BMIp growth rate [β₁ = 0.39 (95% CI: -0.86 to 1.63) and 0.32 (95% CI: -0.86 to 1.63)]. Girls experiencing high social risk at both ages had nonsignificantly but consistently lower BMIp [β₁ = -1.24 (95% CI: -2.93 to 0.46)]. In addition, girls experiencing a sum of ≥4 risk factors at both ages had lower BMIp growth rate [β₁ = -1.77 (95% CI: -3.39 to -0.15)] compared to girls experiencing no risk factor. No associations were observed among boys.

CONCLUSIONS

Early exposure to cumulative social risk may have long-term impact on BMIp trajectories among girls, depending on timing of exposure. Understanding the effect of cumulative social risk in different contexts, including sex, chronicity, and timing of exposure, may have practical implications for informing effective intervention to combat childhood obesity.

Unfolding of hidden white blood cell count phenotypes for gene discovery using latent class mixed modeling

Resting-state white blood cell (WBC) count is a marker of inflammation and immune system health. There is evidence that WBC count is not fixed over time and there is heterogeneity in WBC trajectory that is associated with morbidity and mortality. Latent class mixed modeling (LCMM) is a method that can identify unobserved heterogeneity in longitudinal data and attempts to classify individuals into groups based on a linear model of repeated measurements. We applied LCMM to repeated WBC count measures derived from electronic medical records of participants of the National Human Genetics Research Institute (NHRGI) electronic MEdical Record and GEnomics (eMERGE) network study, revealing two WBC count trajectory phenotypes. Advancing these phenotypes to GWAS, we found genetic associations between trajectory class membership and regions on chromosome 1p34.3 and chromosome 11q13.4. The chromosome 1 region contains CSF3R, which encodes the granulocyte colony-stimulating factor receptor. This protein is a major factor in neutrophil stimulation and proliferation. The association on chromosome 11 contain genes RNF169 and XRRA1; both involved in the regulation of double-strand break DNA repair.

Reciprocal Prospective Relationships Between Loneliness and Weight Status in Late Childhood and Early Adolescence

Adolescents who do not conform to weight ideals are vulnerable to disapproval and victimization from peers in school. But, missing from the literature is a prospective examination of weight status and feelings of loneliness that might come from those experiences. Using data from the Québec Longitudinal Study of Child Development, we filled that gap by examining the prospective associations between loneliness and weight status when the sample was aged 10-13 years. At ages 10, 12, and 13 years, 1042 youth (572 females; 92% from French speaking homes) reported on their loneliness and were weighed and measured. Family income sufficiency was included in our analyses given its relationship with weight status, but also its possible link with loneliness during early adolescence. The findings showed that (1) weight status and loneliness were not associated concurrently; (2) weight status predicted increases in loneliness from ages 12 to 13 years; and (3) loneliness predicted increases in weight from ages 12 to 13 years among female adolescents, but weight loss among male adolescents. The fact that loneliness was involved in weight gain for females suggests that interventions focused on reducing loneliness and increasing connection with peers during early adolescence could help in reducing obesity.

Identifying diverse life transition patterns from adolescence to young adulthood: The influence of early socioeconomic context

The purposes of the present study are to investigate: (1) the heterogeneity in life transition patterns of youth from adolescence to young adulthood (ages 18-30) involving the timing and sequence of four transition events (college graduation, full-time employment, marriage, and parenthood), (2) the influence of early socioeconomic adversity on life transition patterns from adolescence to young adulthood, and (3) the influence of gender and race/ethnicity on these transition patterns. Using a multivariate discrete-time mixture survival model with a sample of 14,503 adolescents from the National Longitudinal Study of Adolescent to Adult Health (Add Health), the study identified four life transition patterns and found that early socioeconomic adversity shapes disrupted life transition patterns from adolescence to young adulthood. Gender and race/ethnicity differences are discussed. These results highlight the need for prevention and intervention programs that selectively target at-risk youth beginning in adolescence and continuing through subsequent transition periods.

The Association of Neighborhood Gene-Environment Susceptibility with Cortisol and Blood Pressure in African-American Adults

BACKGROUND

African-American adults are disproportionately affected by stress-related chronic conditions like high blood pressure (BP), and both environmental stress and genetic risk may play a role in its development.

PURPOSE

This study tested whether the dual risk of low neighborhood socioeconomic status (SES) and glucocorticoid genetic sensitivity interacted to predict waking cortisol and BP.

METHODS

Cross-sectional waking cortisol and BP were collected from 208 African-American adults who were participating in a follow-up visit as part of the Positive Action for Today's Health trial. Three single-nucleotide polymorphisms were genotyped, salivary cortisol samples were collected, and neighborhood SES was calculated using 2010 Census data.

RESULTS

The sample was mostly female (65 %), with weight classified as overweight or obese (M BMI = 32.74, SD = 8.88) and a mean age of 55.64 (SD = 15.21). The gene-by-neighborhood SES interaction predicted cortisol (B = 0.235, p = .001, r (2) = .036), but not BP. For adults with high genetic sensitivity, waking cortisol was lower with lower SES but higher with higher SES (B = 0.87). Lower neighborhood SES was also related to higher systolic BP (B = -0.794, p = .028).

CONCLUSIONS

Findings demonstrated an interaction whereby African-American adults with high genetic sensitivity had high levels of waking cortisol with higher neighborhood SES, and low levels with lower neighborhood SES. This moderation effect is consistent with a differential susceptibility gene-environment pattern, rather than a dual-risk pattern. These findings contribute to a growing body of evidence that demonstrates the importance of investigating complex gene-environment relations in order to better understand stress-related health disparities.

Life events, genetic susceptibility, and smoking among adolescents

Although stressful life events during adolescence are associated with the adoption of unhealthy behaviors such as smoking, both social circumstances and physical traits can moderate the relationship. This study builds on the stress paradigm and gene-environment approach to social behavior by examining how a polymorphism in the serotonin transporter gene 5-HTTLPR moderates the effect of life events on adolescent smoking. Tests of interaction hypotheses use data from the Family Transitions Project, a longitudinal study of 7th graders followed for 5years. A sibling-pair design with separate models for the gender composition of pairs (brothers, sisters, or brother/sister) controls for unmeasured family background. The results show that negative life events are significantly and positively associated with smoking. Among brother pairs but not other pairs, the results provide evidence of gene-environment interaction by showing that life events more strongly influence smoking behavior for those with more copies of the 5-HTTLPR S allele.

Stressful life experiences in adolescence and cardiometabolic risk factors in young adulthood

PURPOSE

An increasing number of studies have provided evidence for the persistent influence of childhood/adolescent socioeconomic adversities on subsequent health outcomes. However, less is known about the distinct and additive influences of these early socioeconomic adversities and adolescents' own stressful life experiences on health outcomes in young adulthood.

METHODS

We used data from 11,030 adolescents who participated in the National Longitudinal Study of Adolescent Health at Waves 1, 3, and 4 and provided biomarker data at Wave 4. Three early socioeconomic adversities (community socioeconomic adversity, family economic hardship, and low parental education) were evaluated. Adolescents' stressful transition to young adulthood was captured by six specific precocious life events as follows: early sex, early marriage or cohabitation, early leaving home, early pregnancy, early employment, and truncated education. A summary measure of cardiovascular and metabolic disease risk was assessed using nine biomarkers. Univariate, bivariate, and multivariate regression analyses were employed.

RESULTS

Early socioeconomic adversities and stressful life transition events were uniquely associated with elevated levels of cardiometabolic (CM) biomarkers and cumulative CM disease risk. For all of the biomarkers, young adults in high-adversity/stress groups were more likely to be in the high CM disease risk groups (>75th percentile) than in the low-adversity/stress groups.

CONCLUSIONS

These findings provide support for the influence of multiple early socioeconomic adversities and adolescents' stressful life transitions on their CM disease risk as young adults. Increased efforts to prevent and mitigate these experiences may improve disease risks across a number of biomarkers.

Interpersonal violence and overweight in adolescents: the HUNT Study

AIMS

Overweight and obesity in children and adolescents are major public health challenges associated with psychosocial adversity and unfavourable lifestyle. Exposure to interpersonal violence, such as sexual abuse, violence and bullying, could represent precursors, accelerating or sustaining factors.

METHODS

The Young-HUNT 3 study, 2006-2008, is a population-based, cross-sectional, cohort study of Norwegian youth that includes self-report data on exposure to interpersonal violence; pubertal status and timing; socioeconomic, psychosocial, and lifestyle factors; and clinical anthropometric measures. A cohort of 10,464 adolescents aged 12-20 years from Nord-Trøndelag County were invited to participate. Body mass index served as the outcome in the simple and multiple linear regression analyses.

RESULTS

The response rate was 72.3% (7564), and 49.9% (3777) of the respondents were girls. A robust and significant relationship between interpersonal violence and increased BMI for both genders was found. Importantly, interpersonal violence remained significantly correlated with higher BMI following adjustment for pubertal development, socioeconomic and psychosocial adversity and unfavourable lifestyle factors in both genders, although most evident in girls. Adjusted regression coefficients (95% confidence intervals) for the relationship between interpersonal violence and BMI were 0.33 (0.01, 0.65) for 1 type and 0.89 (0.37, 1.41) for 2 types, compared to no exposure in girls, and 0.40 (0.09, 0.71) for 1 type and 0.35 (-0.09, 0.79) for 2 types of interpersonal violence in boys.

CONCLUSIONS

The empirical evidence of consistent associations between interpersonal violence, related psychosocial and lifestyle factors, and body fatness, indicates that these features play important roles for adolescents struggling with overweight.

Are stressful developmental processes of youths leading to health problems amplified by genetic polymorphisms? The case of body mass index

Although previous research has documented the adverse influence of early socioeconomic disadvantage on youths' physical health outcomes and the increase in health inequalities over the early life course, little is known about genetically informed sequential life course developmental processes leading to health outcomes. Consistent with the life course-stress process perspective, we hypothesized that early socioeconomic adversity initiates a stress process over the early life course. This process involves the disrupted transition from adolescence to young adulthood, which increases the risk of health problems during young adulthood. Behavioral, psychosocial, and genetic data were collected from 12,424 adolescents (53 % female) over a period of 13 years participating in the nationally representative National Longitudinal Study of Adolescent Health (Add Health). Early cumulative socioeconomic adversity and the polygenic influence were measured using composite indices. The study provided evidence for stressful developmental processes of adolescents, involving parental rejection, depressive symptoms, and adolescents' precocious transition. This longitudinal process was initiated by early cumulative socioeconomic adversity and eventuated with young adults' increased body mass index (BMI). Furthermore, the study provided evidence for the influence of life context-gene interactions (G × E) on adolescents' precocious development and young adult BMI (after controlling for the lagged measure) amplifying the stress process over the early life course. These findings emphasize the need for incorporating individual genetic characteristics in a longitudinal context into life course stress research. Furthermore, policies focused on eradicating childhood/adolescent adversities are necessary as well as youth programs and policies that promote youth competencies that aid in their successful transition to young adulthood.