Child abuse linked to disrupted biological development and body regulation

Children who experienced abuse or neglect displayed disrupted development and 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 in Molecular Psychiatry, was led by Associate Professor Idan Shalev and Qiaofeng Ye, who earned her doctorate from Penn State in 2025. 

The researchers also found that various types of maltreatment affected children differently and that boys were more susceptible to these effects than girls. This study could someday lead to the prevention of health problems in children who have experienced abuse, the authors said, by identifying how physiological changes due to abuse manifest in the body. 

Shalev's prior research on the effects of child abuse focused on biological aging - how old a person's body appears relative to the amount of time they have been alive. Because this study examined the impacts of abuse and neglect in children, the researchers characterized their results as developmental disruption rather than biological aging. 

Genetic information can reveal a great deal about an individual. But to make that information useful, we must understand how it is expressed and connected to specific health outcomes, so that we know how and when to support people. In this study, we applied the Physiological Age Index in a population of children for the first time. This allowed us to examine the impact of child maltreatment 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-Doubal Method, is a tool that researchers around the world use to measure biological age using various blood biomarkers, but it was previously only applied to adult populations. In this study, the researchers compared multiple biomarkers between children who had or had not experienced abuse to determine how the two groups differed. 

The 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 investigation were recruited using the Pennsylvania Child Welfare Information System as cases investigated for suspected maltreatment within the past year. 

Using blood samples, the researchers analyzed nine biomarkers, including multiple measures of blood composition and health, along with measures of cholesterol, blood pressure and heart rate. Because this was the first time the Physiological Age Index had been used in children, the researchers did not have an existing standard for their data. Consequently, they needed to create a reference group to represent a baseline of biomarkers typical for children in the general population. Then, they compared that baseline to the biomarkers of 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 gathered blood samples and physiological data, the researchers were able to match the demographic characteristics - including age and biological sex - of children in the current study with children in the NHANES data. The children in the NHANES group had not been identified as having experienced abuse or neglect. 

When the biomarkers of the maltreatment and comparison groups of children were analyzed, several differences emerged. Children who had experienced sexual abuse displayed disrupted development - specifically, they showed evidence of delayed development - relative to the reference population.

The researchers also found that maltreatment - especially physical abuse - was associated with a lower ability to keep the biomarkers steady and consistent. This consistency, known as "homeostatic regulation," is necessary for maintaining a healthy, working body, according to Ye.

When the researchers examined homeostatic regulation by biological sex, they found that girls did not demonstrate the same levels of weakened homeostatic regulation that boys did.

"Boys showed lower ability to regulate their bodies' internal systems following certain types of abuse," said Shalev, a Penn State Social Science Research Institute co-funded faculty member. "If people respond differently to maltreatment based on their biological sex, we may be able to target support for 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 that this might be the first step to better understanding the mechanisms through which abuse leads to many different health problems. 

"This research contributes to the body of evidence showing that different types of abuse and neglect affect different people in a variety of ways," Shalev said. "As we continue to make connections from gene expression to biomarkers to health problems, we are mapping pathways that may someday allow us to provide exactly 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 contributing to this research included Christopher Chiaro, Laura Etzel, Hannah Schreier and Eric Claus of the Penn State Department of Biobehavioral Health; Abner Apsley of 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 University of North Carolina Chapel Hill; Christine Heim of Freie Universität Berlin and Humboldt-Universität zu Berlin; and Jennie Noll and Chad Shenk of 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.