Maltreatment exposure across childhood and low-grade inflammation: Considerations of exposure type, timing, and sex differences.

Links between child maltreatment and low-grade inflammation in adulthood are well documented, but these studies often rely on adults to report retrospectively on experiences of childhood abuse. Furthermore, these findings raise questions about whether exposure to childhood maltreatment needs time to "incubate," only giving rise to nonresolving inflammation in adulthood, or whether heightened inflammation may be observable in childhood, closer in time to the maltreatment exposure. The present study examined this question in a sample of 155 low-income children (ages 8-12), half of whom had been exposed to maltreatment. Trained coders evaluated case reports to classify maltreatment based on timing and exposure type. Blood samples from children assessed C-reactive protein and cytokines, which were used to form a composite of low-grade inflammation. Analyses revealed a marginally significant Maltreatment Exposure × Sex interaction, which suggested that maltreatment exposure was associated with higher inflammation for girls but not boys. Additionally, analyses focused on the accumulation of maltreatment experiences (through multiple forms of maltreatment or across multiple time points) revealed that girls with greater diversity in their maltreatment experiences and those who experienced maltreatment at multiple time points were at greatest risk. Finally, examination of timing of first onset of maltreatment suggested that girls whose exposures occurred before the age of 5 had the highest low-grade inflammation. These findings add new evidence linking maltreatment to inflammation in childhood, which could increase the risk for mental and physical health problems across the lifespan.