"Heart disease starts in childhood," says lead researcher Kristen Salomon, PhD, social/health psychologist at University of South Florida at Tampa. Her study appears in this month's Health Psychology.
"We need to worry about obesity, exercise, diet," she tells WebMD. "Bad habits develop very early in life. But it's also important to focus on psychological factors, to find kids who are hostile, and help them deal with it."
A handful of studies have suggested that heart disease can begin in early childhood, gets worse with age, and that it is closely tied with weight gain and obesity in childhood -- the result of poor health habits. This is perhaps the first study pointing to hostility as an aggravating factor for children's heart health.
In her study, Salomon focused on 134 children -- between 8-to-10 and 15-to-17 years old -- all recruited from schools in suburban Pittsburgh. "These were healthy, normal kids. We screened them for psychological problems, so these were not pathologically disturbed children," she tells WebMD.
Researchers also tested the kids for hostility, using a questionnaire that "measured their level of cynicism about the world, how they responded to situations when provoked. It measures aggression, how much they tend to feel hostile during the day," Salomon explains.
They interviewed each child to draw out hostility in very subtle ways, she says. Example: "The kids were asked a question, but before they could finish answering it, but the interviewer would cut them off. That provokes people to act aggressively -- make snide remarks, cut off the interviewer in return."
Three years later, kids had all the same tests again.
The "most compelling finding," says Salomon, "was that kids who did not show early signs of heart disease at visit 1 -- but were hostile -- were 22% more likely to have them at visit 2 than kids who weren't hostile."
Hostility, anger, and aggressiveness are complicated reactions with many roots, says John Sargent, MD, child and adolescent psychiatrist at Baylor College of Medicine in Houston. He agreed to discuss the findings with WebMD.
Predatory aggressiveness is one thing: "I want that, and I'm going to take it from you." Reactive aggressiveness is another: "I'm a threatened soul in the universe, watching out for whoever's doing stuff to me, and I'm going to get 'em."
Temperament can predispose some children to anger and hostility, he explains. That behavioral style is largely genetic, yet is affected by environment, he says.
You won't likely see the placid, adaptable kids lash out, Sargent explains. But push a shy child into a new environment, and they might act hostile if they're having trouble adapting, he says.
Also, a "difficult child" is the misfit, the kid who always has some difficulty interacting with the world. "When kids like that grow up among people who don't know how to deal with them effectively, they become more hostile," he explains.
Depressed children -- and children who have witnessed trauma -- can also act with hostility, he tells WebMD. "Kids with a chip on their shoulder, who react intensely to slights or disappointments, can be seen by peers parents teachers as being negative. Sometimes depression and [posttraumatic stress disorder] coincide. Sometimes depression is a response to trauma or adversity."
Bottom line, he says: Helping angry children will improve the quality of their lives, helping them have more friends and a better self-image. Such positive influences may help children take better care of themselves, offsetting the risk for heart disease.