Co-Rooming Accounts for Socioeconomic Disparities in Infant Sleep Quality among Families Living in Urban Environments.

Poor infant sleep quality is associated with negative maternal and infant health outcomes. This study measures socioeconomic disparities in infant sleep quality, and assesses whether child sleep location and maternal stress mediate associations between socioeconomic status (SES) and infant sleep quality. The study includes 86 socioeconomically diverse, mother-infant dyads living in an urban area with infants aged 6-12 months. Mothers reported socioeconomic demographics, infant sleep quality (Brief Infant Sleep Questionnaire) and maternal subjective stress (Perceived Stress Scale). Maternal objective stress was measured via hair cortisol concentration (HCC). The associations among SES, infant sleep quality, infant co-rooming, and maternal stress were assessed. Infants from families with lower income-to-needs (ITN) ratios had poorer infant sleep quality. The association between familial ITN and infant sleep quality was mediated by whether the child co-rooms with parents. Maternal perceived stress was independently associated with infant sleep quality, but HCC was not associated with infant sleep quality.

Socioeconomic factors, stress, hair cortisol, and white matter microstructure in children.

Socioeconomic disadvantage has been linked to increased stress exposure in children and adults. Exposure to stress in childhood has been associated with deleterious effects on cognitive development and well-being throughout the lifespan. Further, exposure to stress has been associated with differences in brain development in children, both in cortical and subcortical gray matter. However, less is known about the associations among socioeconomic disadvantage, stress, and children's white matter development. In this study, we investigated whether socioeconomic disparities would be associated with differences in white matter microstructure in the cingulum bundle, as has been previously reported. We additionally investigated whether any such differences could be explained by differences in stress exposure and/or physiological stress levels. White matter tracts were measured via diffusion tensor imaging in 58 children aged 5-9 years. Results indicated that greater exposure to stressful life events was associated with higher child hair cortisol concentrations. Further, physiological stress, as indexed by hair cortisol concentrations, were associated with higher fractional anisotropy in the cingulum bundle. These results have implications for better understanding how perceived and physiological stress may alter neural development during childhood.

Assessment of prenatal stress-related cortisol exposure: focus on cortisol accumulation in hair and nails.

Prenatal stress adversely affects offspring development. Although cortisol is hypothesized to be a key mediator of stress-induced developmental deficits, determining the amount of fetal cortisol exposure produced by maternal stress has proved challenging. Current approaches, such as measuring cortisol concentrations in maternal plasma, saliva, or urine, amniotic fluid, fetal plasma, or cord blood, all have significant limitations for assessing cumulative fetal cortisol exposure over time. A recently emerging approach is to measure cortisol concentrations in maternal hair and/or newborn hair or nail samples. Maternal hair cortisol potentially shows long-term production across each trimester of pregnancy, whereas neonatal hair or nail cortisol is thought to reflect mainly third trimester hormone accumulation. This review first describes fetal adrenocortical development, placental cortisol metabolism, and the various sources of fetal cortisol exposure across pregnancy. We then summarize the results obtained from "classical" methods of assessing prenatal cortisol exposure prior to the advent of hair and nail cortisol measurement. Lastly, we discuss the initial development and validation of the hair cortisol methodology, its subsequent application to studies of chronic stress, and recent findings regarding maternal and neonatal hair or nail cortisol concentrations in relation to prenatal stress and other variables of interest.

Physiological and economic benefits of abandoning invasive surgical procedures and enhancing animal welfare in swine production.

Food-animal welfare is a major ethical and social concern. Pork is the most consumed meat worldwide, with over a billion pigs slaughtered annually. Most of these pigs routinely undergo painful surgical procedures (surgical castration, tail docking, teeth clipping), which farmers often reluctant to avoid, claiming it would increase cost and reduce production efficiency. Herein, this study indicates that these procedures compromise pigs' health and condition. Replacing surgical castration with immunocastration, avoiding tail docking and teeth clipping, and providing environmental enrichment, resulted in significant increase in weight gain, lowered risks for injuries and death, and reduced saliva and hair cortisol, both biomarkers for stress. Testosterone and DHEA analyses confirmed that immunocastration was an effective alternative to surgical castration. Economic models for the entire US swine market revealed that following across-the-board acceptance of this management, pork meat price is expected to drop, while the total annual social welfare (combined consumer and producer surplus) is expected to increase by $US 1.48 to 1.92 billion. In conclusion, sustainable swine farming management can be beneficial for both animals and farmers. Applying such welfare-friendly management is expected to reduce stress, enhance piglet/pig welfare and production, and improve the economics of swine operations in the global agro-food system.

Emotion regulation moderates the association between parent and child hair cortisol concentrations.

Successful emotion regulation facilitates children's coping with everyday stress. It develops rapidly in the early preschool period. However, no work has been done to investigate the potential buffering role of emotion regulation from cumulative physiological effects of stress. In this study, we examined hair cortisol concentration (HCC), an early marker of chronic physiological stress, socioeconomic status (SES), parental sensitivity, and emotion regulation and reactivity in a sample of 3.5-year-old children (N = 86). Emotion regulation and emotional reactivity were independent of child HCC. However, emotion regulation moderated the relationship between parent and child HCC. For children with better emotion regulation, there was no association between parent and child HCC, suggesting that emotion regulation skills buffered the transgenerational effects of chronic physiological stress. Emotional reactivity moderated the relationship between SES and child HCC, and attenuated the association between parental sensitivity and child HCC. Taken together, these findings demonstrate that children who were less emotionally reactive were less susceptible to their environments. Results provide support that child emotion regulation and emotional reactivity can reduce or strengthen the relationship between established risk factors and levels of chronic physiological stress in early childhood.