A study of 13-year-olds in Portugal found that children exposed to certain adverse experiences before age 10 were more likely to have increased allostatic load during adolescence. Additional adverse experiences by age 13 further amplify this association. The paper is brain, behavior, immunity.
Adverse childhood experiences (ACEs) are potentially traumatic events that occur during childhood that can have a lasting impact on health and well-being. These typically include experiences of abuse, neglect, and family dysfunction before the age of 18. Examples include physical, mental, or sexual abuse, emotional or physical neglect, and exposure to domestic violence. It also includes growing up in a household with substance abuse, mental illness, parental incarceration, or parental separation.
Research shows that the more people experience ACEs, the higher their risk of developing mental and physical health problems later in life. High exposure to ACEs is associated with increased risk of depression, anxiety, substance abuse, and chronic disease.
One important mechanism is chronic activation of the stress response, which can affect brain development and immune function. However, not everyone who experiences ACEs develops negative outcomes, as protective factors such as supportive relationships and stable environments may promote resilience.
Study author Armine Abrahamyan and colleagues wanted to estimate allostatic load at age 13 and assess whether exposure to ACEs during the first decade of life was associated with it. Allostatic load is the cumulative physiological “wear and tear” on the body caused by repeated or chronic activation of stress response systems.
Over time, this long-term stress-related activation can cause dysregulation of multiple biological systems, including the cardiovascular, metabolic, immune, and renal systems, resulting in increased risk for a variety of physical and mental health problems.
The authors of this study analyzed data from Generation XXI, a population-based birth cohort in Porto, Portugal. The group initially consisted of 8,647 children born in 2005 and 2006 in public maternity wards in the Porto metropolitan area. However, only 54% of the group had provided data to researchers by age 13. The analyzes presented in the paper are based on an analytical sample of 3,787 participants (1,979 of whom were boys).
Participants completed an assessment of childhood adversity experiences at ages 10 and 13 (this questionnaire was adapted from the Childhood Adversity Experience Study and the Child and Youth Experience Study: Children’s Edition). At age 13, they provided blood samples and underwent physical measurements to measure blood pressure and heart rate. Measurement of allostatic load was based on a combination of functional data of the cardiovascular system, metabolic system, immune and inflammatory system, and renal function.
Results showed that total scores for adverse experiences at age 10 were not associated with higher allostatic load at age 13, but specific individual traumas such as parental separation or divorce before age 10 were. Additionally, participants who accumulated more total adverse childhood experiences by age 13 showed significantly higher overall allostatic load at the same age.
Parental separation or divorce, difficulties at school, or alcohol/drug use in the home that occurred between participants’ ages 10 and 13 were associated with increased allostatic load at age 13. Overall, the metabolic and immune systems tended to be most responsive to adverse childhood experiences.
“These findings suggest that adolescents exposed to selected ACEs at age 10 years show increased AL (allostatic load) load, and that cumulative ACEs by age 13 years further amplify this association,” the study authors concluded.
This study contributes to scientific understanding of the association between overall health and adverse childhood experiences. However, it should be noted that almost half of the initial number of participants dropped out of the study by the last measurement period. This may have influenced the results, as youth from more disadvantaged backgrounds (often facing greater adversity) were more likely to drop out, and thus may have underestimated the true magnitude of physical harm.
The paper, “Childhood Adversity Experiences and Adolescent Physiological Depletion: Findings from the 21st Generation Cohort,” was authored by Armine Abrahamyan, Milton Severo, Michelle Kelly-Irving, Liane Correia-Costa, Mariana Amorim, Sara Soares, and Sílvia Fraga.
