Children and teens with low cholesterol levels seem to be more likely to be suspended from school, according to researchers. They suggest that “low total cholesterol may be a risk factor for aggression or a risk marker for other biologic variables that predispose to aggression.”

Dr. Jian Zhang, of the University of South Carolina in Columbia and colleagues note that “dietary guidelines developed for adults have been extended to children, but the role of serum cholesterol in the neurodevelopment of children is poorly understood.”

In their study, published in the American Journal of Epidemiology, the investigators used data from the Third National Health and Nutrition Examination Survey to examine the association between blood levels of cholesterol and psychosocial development of non-institutionalized children and adolescents.

Total cholesterol was measured in 4852 children between the ages of 6 and 16 years. Interviews with the mothers were conducted regarding the children’s history of school suspensions or expulsion and difficulty in getting along with others.

Zhang’s group found that among children with various cholesterol levels, there were no differences in the proportion who had seen a mental health professional.

However, non-African American children with cholesterol below 145 milligrams per deciliter were nearly three times more likely to have been suspended or expelled from school than their peers with cholesterol above this level.

“It is possible that at least part of the association of low total cholesterol with school suspension is explainable by a reverse causation,” Zhang’s team suggests.

That is, “School suspension appears to have serious negative psychiatric consequences, including elevated depressive symptoms and post-traumatic stress disorder,” they explain. “Post-traumatic Stress Disorder may result in a fall in cholesterol concentration.”

Whatever the cause-and-effect, “both psychological and biologic consequences of school suspension or expulsion on children and adolescents deserve further examination,” the researchers conclude.

SOURCE: American Journal of Epidemiology, April 1, 2005.