People who were physically or sexually abused as children are twice as likely to have inflammatory proteins in their blood, according to a new study. The findings could explain why children who are abused show a higher incidence of conditions such as heart disease and diabetes as adults, the researchers say. Until now, it has not been clear exactly how early stress could cause these future health problems, says Andrea Danese, a psychiatrist at King's College London in the UK.

Danese and colleagues monitored 1000 people in New Zealand from birth to the age of 32, noting factors that created stress and measuring for levels of inflammation associated with heart disease in their bloodstream. They found that people who had been physically or sexually abused, or rejected by their mothers as children were twice as likely to have significant levels of the C-reactive protein, a measure of inflammation.

Anticipation of pain

The team believes that stress induces abnormal levels of inflammation in children, which has repercussions in adulthood. "Inflammation is a natural response to physical trauma, such as cutting yourself or getting an infection," explains Danese. "But psychological stress can also trigger inflammation, since stress is really the anticipation of pain."

This constant triggering could reduce the children's ability to produce glucocorticoid hormones that suppress inflammation, leading to an increase risk of heart disease, stroke, and other illnesses as adults, says Danese. The team plan further work to measure glucocorticoid levels.

"This is much stronger than simply saying that people who have a harder time in childhood are more miserable or depressed as adults," says Andrew Steptoe at University College London, who has studied the relationship between emotional triggers and heart disease. "They've elegantly connected childhood to stress to a real adult risk of disease."

Danese hopes that the study will help practitioners to identify abused children as having a high risk of heart disease at an earlier age.