Frontal brain asymmetry, childhood maltreatment, and low-grade inflammation at midlife

Frontal EEG asymmetry is thought to reflect variations in affective style, such that greater relative right frontal activity at rest predicts enhanced emotional responding to threatening or negative stimuli, and risk of depression and anxiety disorders. A diathesis-stress model has been proposed to explain how this neuro-affective style might predispose to psychopathology, with greater right frontal activity being a vulnerability factor especially under stressful conditions. Less is known about the extent to which greater relative right frontal activity at rest might be associated with or be a diathesis for deleterious physical health outcomes. The present study examined the association between resting frontal EEG asymmetry and systemic, low-grade inflammation and tested the diathesis-stress model by examining whether childhood maltreatment exposure interacts with resting frontal asymmetry in explaining inflammation. Resting EEG, serum inflammatory biomarkers (interleukin-6, C-reactive protein, and fibrinogen) and self-reported psychological measures were available for 314 middle-aged adults (age M = 55.3 years, SD = 11.2, 55.7% female). Analyses supported the diathesis-stress model and revealed that resting frontal EEG asymmetry was significantly associated with inflammation, but only in individuals who had experienced moderate to severe levels of childhood maltreatment. These findings suggest that, in the context of severe adversity, a trait-like tendency towards greater relative right prefrontal activity may predispose to low-grade inflammation, a risk factor for conditions with inflammatory underpinnings such as coronary heart disease

Intervention effects on diurnal cortisol rhythms of Child Protective Services-referred infants in early childhood: preschool follow-up results of a randomized clinical trial.

IMPORTANCE: A number of interventions for at-risk children have shown benefits for childrens hypothalamic-pituitary-adrenal axis activity immediately after treatment. It is critical to examine whether such changes are maintained over time, given that physiological regulation is implicated in later mental and physical health outcomes. OBJECTIVE: To examine whether differences in diurnal cortisol production between children receiving the active parenting intervention and children in the control group persisted at a preschool follow-up (approximately 3 years following intervention). DESIGN, SETTING, AND PARTICIPANTS: Between-subject comparison of cortisol patterns among 2 groups of children (experimental and control groups) involved with Child Protective Services following allegations of neglect. The participants included 115 children (43.5% female) between 46.5 and 69.6 months of age (mean [SD], 50.73 [4.98] months) who had been previously randomly assigned to either the Attachment and Biobehavioral Catch-up (ABC) intervention (n = 54) or the control intervention (n = 61). INTERVENTIONS: The experimental ABC intervention focused on 3 aims: increasing parental nurturance to child distress, increasing synchronous interactions, and decreasing frightening parental behavior. The control intervention provided educational information about child development to parents. Both interventions were manualized and involved 10 sessions implemented by a trained parent coach in the families homes or other places of residence. MAIN OUTCOMES AND MEASURES: Salivary cortisol samples collected at waking and bedtime for children on 3 separate days. RESULTS: Analyses revealed significant differences in cortisol production at the preschool follow-up, such that children in the ABC intervention group showed more typical patterns of cortisol production than children in the control intervention group. Specifically, children in the ABC group exhibited higher mean (SD) log-transformed morning levels than children in the control group (-0.87 [0.45] vs -1.05 [0.43] μg/dL, respectively [to convert to nanomoles per liter, multiply by 27.588]; β = 0.18; P = .03). Bedtime cortisol levels did not differ significantly between the ABC and DEF groups (mean [SD], -1.19 [0.49] vs -1.17 [0.48] μg/dL, respectively; β01 = -0.01; P = .87). Those in the ABC group showed a steeper decline in cortisol across the day (mean, -0.31 μg/dL) than those in the control group, who showed a blunted cortisol rhythm (mean, -0.12 μg/dL) (β = -0.19; P = .02). CONCLUSIONS AND RELEVANCE: Differences in cortisol production between the experimental and control groups persisted at the preschool follow-up and resembled differences initially observed 3 months following intervention. This is encouraging evidence that the ABC intervention for Child Protective Services-referred children may have long-lasting effects on a physiological stress system critical for health and adjustment. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT02093052

Longitudinal associations between attachment quality in infancy, C-reactive protein in early childhood, and BMI in middle childhood: preliminary evidence from a CPS-referred sample.

In the current pilot study, we examined whether insecure or disorganized attachment was associated with elevated inflammation (i.e. C-reactive protein [CRP]) in children with histories of child protective services (CPS) involvement, and whether early childhood CRP predicted body mass index (BMI) in middle childhood. Participants included 45 CPS-referred children and 39 low-risk comparison children, for whom we assessed levels of CRP in early childhood (Mean age = 4.9 years). For the CPS-referred children, who were drawn from an ongoing longitudinal study, we had attachment classifications (assessed during infancy with the Strange Situation) and BMI data (assessed during early and middle childhood); these data were not available for the low-risk comparison group. CPS-referred children who had insecure or disorganized attachments during infancy had higher levels of CRP in early childhood than CPS-referred children who had secure attachments, who had similar levels of CRP to low-risk comparison children. Among CPS-referred children, early childhood CRP predicted age 8 BMI, controlling for BMI at age 4. Findings offer preliminary support for the association between attachment quality and inflammation in early childhood, which may have implications for later physical health

Early-Life Socioeconomic Disadvantage and Metabolic Health Disparities.

OBJECTIVE: A quarter of the worlds population have metabolic syndrome (MetS). MetS prevalence is stratified by socioeconomic status (SES), such that low SES is associated with higher MetS risk. The present study examined the relative roles of early-life SES and current SES in explaining MetS risk. METHODS: Participants (N = 354; ages = 15-55 years, M [SD] = 36.5 [10.7] years; 55% female; 72.9% white, 16.9% Asian, 10.2% others) were evaluated for SES and MetS. All were in good health, defined as free of chronic medical illness and acute infectious disease. Using occupational status as a proxy for SES, we recruited roughly equal numbers of participants with low-low, low-high, high-low, and high-high combinations of early-life and current SES. We used the International Diabetes Federation definition for MetS using race- and sex-specific cutoffs for waist circumference, triglyceride levels, high-density lipoprotein cholesterol, blood pressure, and glycosylated hemoglobin levels. RESULTS: Analyses revealed a main effect of low early-life SES on increased MetS risk according to the three separate definitions. They included the traditional MetS diagnosis (odds ratio [OR] = 1.53, confidence interval [CI] = 1.01-2.33, p = .044), the number of MetS components for which diagnostic thresholds were met (OR = 1.61, CI = 1.10-2.38, p = .015), and a continuous indicator of metabolic risk based on factor analysis (F(1,350) = 6.71, p = .010, partial η = .019). There was also a significant interaction of early-life SES and current SES in predicting MetS diagnosis (OR = 1.54, CI = 1.02-2.34). The main effects of current SES were nonsignificant in all analyses. CONCLUSIONS: These findings suggest that MetS health disparities originate in childhood, which may be an opportune period for interventions

The impacts of social support and early life stress on stress reactivity in children and adolescents

University of Minnesota Ph.D. dissertation. August 2013. Major:Child Psychology. Advisor:Megan R. Gunnar, Ph.D. 1 computer file (PDF); v, 115 pages.The goal of the present study was to investigate the impacts of social support and early life stress on individual differences in HPA axis reactivity in children (ages 9-10) and adolescents (ages 15-16). The primary aims were: 1) to experimentally manipulate the provision of social support in the laboratory and examine its effect on levels of salivary cortisol in response to the Trier Social Stress Test for Children; 2) to investigate parenting quality variables that may moderate the social buffering effect based on coding of videotaped parent-child interactions; 3) to analyze the role of early life stress (orphanage-rearing versus birth family rearing) and current social network characteristics in predicting the cortisol response; and 4) to explore age and sex differences in stress reactivity and the social buffering of stress. A sample of 162 participants was recruited, roughly equally divided between the two age groups, experimental conditions (half were exposed to a parent support condition before the stress task, whereas half received support from a stranger), early life experience (adopted or non-adopted) and by gender. Analyses of cortisol stress responses revealed that in the non-adopted group parent support provided in the laboratory significantly dampened stress reactivity in children but not in adolescents when compared to the stranger support condition. Additionally, participants reared in orphanages showed atypical patterns of HPA reactivity and of responses to social support provided before the stressor. Implications and future directions are discussed

Racial/ethnic disparities in cortisol diurnal patterns and affect in adolescence.

Racial/ethnic minorities are more vulnerable to mental and physical health problems, but we know little about the psychobiological underpinnings of these disparities. In this study, we examined racial/ethnic differences in cortisol diurnal patterns and affect as initial steps toward elucidating long-term health disparities. A racially/ethnically diverse (39.5% White, 60.5% minority) sample of 370 adolescents (57.3% female) between the ages of 11.9 and 18 years (M = 14.65 years, SD = 1.39) participated in this study. These adolescents provided 16 cortisol samples (4 samples per day across 4 days), allowing the computation of diurnal cortisol slopes, the cortisol awakening response, and diurnal cortisol output (area under the curve), as well as daily diary ratings of high-arousal and low-arousal positive and negative affect. Consistent with prior research, we found that racial/ethnic minorities (particularly African American and Latino youth) exhibited flatter diurnal cortisol slopes compared to White youth, F (1, 344.7) = 5.26, p = .02, effect size g = 0.25. Furthermore, African American and Asian American youth reported lower levels of positive affect (both high arousal and low arousal) compared to White youth. Racial/ethnic differences in affect did not explain differences in cortisol patterns, suggesting a need to refine our models of relations between affect and hypothalamic-pituitary-adrenocortical activity. We conclude by proposing that a deeper understanding of cultural development may help elucidate the complex associations between affect and hypothalamic-pituitary-adrenocortical functioning and how they explain racial/ethnic differences in both affect and stress biology

Understanding the Development of Chronic Loneliness in Youth.

Loneliness becomes more prevalent as youth transition from childhood into adolescence. A key underlying process may be the puberty-related increase in biological stress reactivity, which can alter social behavior and elicit conflict or social withdrawal (fight-or-flight behaviors) in some youth, but increased prosocial (tend-and-befriend) responses in others. We propose an integrative theoretical model that identifies the social, personality, and biological characteristics underlying individual differences in social-behavioral responses to stress. This model posits a vicious cycle whereby youth who respond to stress with fight-or-flight tendencies develop increasing and chronic levels of loneliness across adolescence, whereas youth who display tend-and-befriend behaviors may be buffered from these consequences. Based on research supporting this model, we propose multiple intervention avenues for curtailing the prevalence of loneliness in adolescence by targeting key factors involved in its development: social relationships, personality, and stress-induced behavioral and biological changes

Heart rate variability and circulating inflammatory markers in midlife

Theoretical perspectives and empirical evidence suggest that the parasympathetic nervous system engages in active monitoring and moderating of inflammatory processes. A clearer understanding of the bidirectional communication between the parasympathetic nervous system and the immune system could lead to novel clinical interventions for inflammatory illnesses. The current study used a large (N = 836) nationally representative sample of adults in the United States to investigate the relations between resting parasympathetic modulation of the heart, indexed through both high frequency heart rate variability (HF-HRV) and low frequency heart rate variability (LF-HRV), and six markers of circulating inflammation. Statistical analyses revealed robust inverse relations between HF-HRV and interleukin-6 (IL6), C-reactive protein (CRP), and fibrinogen, with or without covariate adjustment. Similar inverse relations were observed between LF-HRV and IL6 and CRP. No significant relations were observed between HRV and either inflammatory adhesion molecules (E-selectin, intracellular adhesion molecule-1) or soluble IL6 receptor. Results are consistent with the cholinergic anti-inflammatory pathway and suggest that parasympathetic modulation of inflammation through the vagus nerve may act on specific inflammatory molecules more than others

Curvilinear associations between family income in early childhood and the cortisol awakening response in adolescence

Previous evidence on cortisol output and socioeconomic status (SES) has been mixed, with studies finding that lower SES can be associated with higher or lower cortisol output, and null associations have also been reported. We hypothesized that these inconsistencies may be due to an underlying curvilinear, inverted-U pattern of association, such that low income is related to increased likelihood of both low and high cortisol output. We tested these curvilinear links among family income and cortisol indices in the Avon Longitudinal Study of Parents and Children (N = 803). Maternal reports of family income when the study children were 33 and 47 months of age were averaged to estimate early-childhood family income. Three cortisol indices were derived from samples collected in adolescence (15.5 years of age): the cortisol awakening response (CAR), area under the curve (AUC) cortisol, and the diurnal cortisol slope. As hypothesized, the CAR exhibited a curvilinear, inverted-U relation with childhood income, with low childhood income being associated with both the lowest and the highest CARs. These findings suggest that discrepancies in prior findings on low SES and the CAR may be due to curvilinear patterns of association. However, childhood income was not significantly associated with adolescent cortisol diurnal slope or AUC. Future work should clarify the factors that might predispose to high versus low CAR given equivalent low SES in childhood

Clearing the air: A systematic review of studies on air pollution and childhood brain outcomes to mobilize policy change

Climate change, wildfires, and environmental justice concerns have drawn increased attention to the impact of air pollution on children's health and development. Children are especially vulnerable to air pollution exposure, as their brains and bodies are still developing. The objective of this systematic review was to synthesize available empirical evidence on the associations between air pollution exposure and brain outcomes in developmental samples (ages 0-18 years old). Studies were identified by searching the PubMed and Web of Science Core Collection databases and underwent a two-phase screening process before inclusion. 40 studies were included in the review, which included measures of air pollution and brain outcomes at various points in development. Results linked air pollution to varied brain outcomes, including structural volumetric and cortical thickness differences, alterations in white matter microstructure, functional network changes, metabolic and molecular effects, as well as tumor incidence. Few studies included longitudinal changes in brain outcomes. This review also suggests methodologies for incorporating air pollution measures in developmental cognitive neuroscience studies and provides specific policy recommendations to reduce air pollution exposure and promote healthy brain development by improving access to clean air