Cumulative effects of early poverty on cortisol in young children: Moderation by autonomic nervous system activity

Abstract

The relation of the cumulative experience of poverty in infancy and early childhood to child cortisol at age 48 months was examined in a prospective longitudinal sample of children and families (N=1,292) in predominantly low-income and rural communities in two distinct regions of the United States. Families were seen in the home for data collection and cumulative experience of poverty was indexed by parent reported income-to-need ratio and household chaos measures collected between child ages 2mos and 48mos. For the analysis presented here, three saliva samples were also collected over an approximate 90 minute interval at child age 48mos and were assayed for cortisol. ECG data were also collected during a resting period and during the administration of a mildly challenging battery of cognitive tasks. Mixed model analysis indicated that child cortisol at 48 months decreased significantly over the sampling time period and that cumulative time in poverty (number of years income-to-need less than or equal to 1) and cumulative household chaos were significantly related to a flatter trajectory for cortisol change and to an overall higher level of cortisol, respectively. Findings also indicated that respiratory sinus arrhythmia derived from the ECG data moderated the association between household chaos and child cortisol and that increase in respiratory sinus arrhythmia during the cognitive task was associated with an overall lower level of cortisol at 48 months.

Maternal distress and child neuroendocrine and immune regulation

“…These results are consistent with studies showing blunted physiologic stress responses among low-SES children (Blair, Berry, Mills-koonce, Granger, & The FLP Investigators, 2013; Evans & Kim, 2007). SES-related differences in cortisol likely reflect a combination of psychosocial and environmental effects.…”

Prenatal Drug Exposure Moderates the Association between Stress Reactivity and Cognitive Function in Adolescence

“…Prior research suggests that early life stressors compound the effects of prenatal stressors by chronically over-activating physiological systems such as the HPA axis, eventually leading to down-regulation of the response until an individual demonstrates a blunted response [10–16]. Two recent studies found that the effects of poverty, financial instability, and caregiver instability accumulated over time resulting in a decline in cortisol [14] and time in poverty along with household chaos were associated with a flattened cortisol change trajectory [16]. PDE is often associated with multiple stressors such as non-supportive or absent caregivers, few financial resources, neighborhood and/or home violence exposure, continued caregiver drug use, multiple out-of-home placements, and increased likelihood of various forms of abuse [46].…”

“…These disruptions may prevent an expected stress response, resulting in a blunted cortisol or atypical response to stress over time [10,11]. This process has been demonstrated in maltreated and deprived/neglected children [10–13] and in children with early life stress (e.g., harsh parenting, poverty) [14–16]. …”

How Socioeconomic Disadvantages Get Under the Skin and into the Brain to Influence Health Development Across the Lifespan

“…SED is associated with elevated baseline levels of cortisol during childhood (Essex et al 2002;Evans and English 2002;Flinn and England 1997;Gustafsson et al 2006;Lupien et al 2001;Lupien et al 2000) and adolescence although Lupien et al (2001) found that by age 12, SES is no longer related to baseline cortisol levels. The longer children experience poverty, the higher the cortisol level (Blair et al 2013). In a particularly noteworthy study, Chen et al (2010) examined salivary cortisol every 6 months for a 2-year period among a group of adolescents.…”