Childhood and later life stressors and increased inflammatory gene expression at older ages

Abstract

Adverse experiences in early life have the ability to "get under the skin" and affect future health. This study examined the relative influence of adversities during childhood and adulthood in accounting for individual differences in pro-inflammatory gene expression in late life. Using a pilot-sample from the Health and Retirement Study (N = 114) aged from 51 to 95, OLS regression models were run to determine the association between a composite score from three proinflammatory gene expression levels (PTGS2, ILIB, and IL8) and 1) childhood trauma, 2) childhood SES, 3) childhood health, 4) adult traumas, and 5) low SES in adulthood. Our results showed that only childhood trauma was found to be associated with increased inflammatory transcription in late life. Furthermore, examination of interaction effects showed that childhood trauma exacerbated the influence of low SES in adulthood on elevated levels of inflammatory gene expression-signifying that having low SES in adulthood was most damaging for persons who had experienced traumatic events during their childhood. Overall our study suggests that traumas experienced during childhood may alter the stress response, leading to more sensitive reactivity throughout the lifespan. As a result, individuals who experienced greater adversity in early life may be at higher risk of late life health outcomes, particularly if adulthood adversity related to SES persists.

Keywords: Inflammation; Social genomics; Stress.

Figure 1. The Association Between Predicted Means of Proinflammatory Gene Expression and the Interaction of Childhood Traumas and Low SES in Adulthood

The interaction between childhood traumas and low SES in adulthood was significantly associated with expression (β=0.81, P=.034). Among participants who reported experiencing two early life traumas, low SES in adulthood was positively associated with RNA composite scores of inflammatory gene expression. This association was less strong for participants who only reported experiencing one of the early life traumas. Finally, among those with no reported early life traumas, we found no significant difference in levels of gene expression between individuals with low SES and those with moderate or high SES. Error bars correspond to standard errors of predicted means.