Children who experienced abuse or neglect have disrupted development and a decreased ability to maintain stable function of internal bodily systems, according to a new study led by researchers in the Penn State Department of Biobehavioral Health.
The study, published May 7 molecular psychiatryLed by Associate Professors Idan Shalev and Qiaofeng Ye, who received their doctorates from Penn State in 2025.
Researchers also found that different types of abuse have different effects on children and that boys are more vulnerable to these effects than girls. This study may someday lead to the prevention of health problems in children who experience abuse, the authors said, by identifying how physical changes in the body manifest due to abuse.
Shalev’s prior research on the effects of child abuse focused on biological aging – how old a person’s body looks relative to the length of time he or she has lived. Because this study examined the effects of abuse and neglect in children, the researchers described their results as developmental disruption rather than biological aging.
Genetic information can tell a lot about a person. But to make that information useful, we need to understand how it is expressed and linked to specific health outcomes, so we know how and when to support people. In this study, we applied the physical age index in the pediatric population for the first time. This allowed us to examine the impact of child abuse on biological changes in the body that are more closely related to health outcomes.”
Qiaofeng Ye, first author of the study
The Physiological Age Index, also known as the Klemera-Double method, is a tool used by researchers around the world to measure biological age using various blood biomarkers, but previously it was only applicable to adult populations. In this study, researchers compared several biomarkers between children who did and did not experience abuse to determine how the two groups differed.
Researchers compared data from 461 children in the Penn State Child Health Study, most of whom had experienced abuse within the past year, to a comparison group of children who had not experienced abuse. Children with a history of maltreatment were recruited using the Pennsylvania Child Welfare Information System as cases of suspected maltreatment within the past year.
Using blood samples, the researchers analyzed nine biomarkers, including measures of cholesterol, blood pressure and heart rate, as well as several measures of blood composition and health. Since this was the first time the physical age index was used in children, the researchers had no existing standards for their data. As a result, they needed to create a reference group to represent a baseline of specific biomarkers for children in the general population. Then, they compared that baseline to biomarkers from children in the Child Health Study.
To create the reference group, the researchers used data from the National Health and Nutrition Examination Survey (NHANES), a study conducted by the National Center for Health Statistics. Because NHANES also collected blood samples and physical data, the researchers were able to match the demographic characteristics of the children in the current study – including age and biological sex – with the children in the NHANES data. Children in the NHANES group were not identified as having experienced abuse or neglect.
When the biomarkers of child abuse and comparison groups were analyzed, several differences emerged. Children who had experienced sexual abuse had disrupted development – specifically, they showed evidence of delayed development relative to the reference population.
The researchers also found that abuse – especially physical abuse – was associated with a reduced ability to keep the biomarkers stable and consistent. According to Ye, this stability, known as “homeostatic regulation”, is essential to maintaining a healthy, functioning body.
When researchers examined homeostatic regulation by biological sex, they found that girls did not exhibit the same weak homeostatic regulation as boys.
“The boys showed a reduced ability to regulate their body’s internal systems after certain types of abuse,” said Shelev, a co-funded faculty member of the Penn State Social Science Research Institute. “If people respond differently to abuse based on their biological sex, we may be able to target support to individuals, depending on who they are and what they have experienced.”
Because this type of analysis has never been applied to children before, the researchers said their results need to be confirmed by other studies, but it could be a first step toward better understanding the mechanisms through which maltreatment leads to many different health problems.
Shalev said, “This research contributes to the evidence showing that different types of abuse and neglect affect different people in different ways.” “As we continue to make connections from gene expression to biomarkers to health problems, we are creating pathways that may someday allow us to provide the care that each individual needs. We are not there yet, but my lab and many others around the world will continue to work to solve these problems.”
Others who contributed to this research included Christopher Chiaro, Laura Etzel, Hannah Schreiber and Eric Kloss of the Penn State Department of Biobehavioral Health; Abner Apsley of the University of Illinois at Urbana-Champaign; Waylon Hastings of Texas A&M University; Alan Cohen of the Columbia University Mailman School of Public Health; Zachary Fisher of the University of North Carolina Chapel Hill; Christine Heim of the Freie Universität Berlin and Humboldt-Universität zu Berlin; and Jenny Noll and Chad Schenk of the University of Rochester.
This research was funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development and the National Center for Advancing Translational Sciences.
