The role of inflammation in the association between poverty and working memory in childhood

Abstract

Background: Family financial difficulties have been directly linked to poorer executive functioning in childhood. However, recent studies suggest that difficulties in affording basic items and other necessities may also indirectly affect children's executive functions through several psychological but also physiological paths. One of the latter may be inflammation, which has been related to both financial difficulties and executive functioning. In this study, we explored for the first time if the relationship between early family financial difficulties and working memory in middle childhood can be explained by inflammation.

Methods: Using data from 4,525 children of the Avon Longitudinal Study of Parents and Children, a general population birth cohort, we tested associations between parents' perceptions at ages 0-3 years of having difficulties in affording basic items for their children including food and clothing, children's inflammation [measured by interleukin 6 (IL-6) and C-reactive protein (CRP)] at age 9 years and working memory performance at age 10 years. Confounders included socioeconomic status at ages 0-3 years, economic hardship between ages 3-9 years, BMI and gender.

Results: Using Structural Equation Modelling, we found that financial difficulties were associated with worse working memory (β=-0.076, 95 % CI=-0.105, -0.043) even after adjusting for confounders. This association was partially explained by inflammation (β=-0.002, 95 % CI=-0.005, -0.001) as measured by IL-6.

Conclusions: Children in families struggling to afford necessities early in life have higher levels of inflammation, in turn related to poorer executive functioning in middle childhood. These findings suggest that living under financial strain has a unique effect on children's cognitive development through inflammation in the general population.

Keywords: ALSPAC; Childhood; IL-6; Inflammation; SES; Working memory.