SAN FRANCISCO, Sept. 21 (UPI) -- Parents joke about the toll children take on their health, but mothers of autistic children who report chronic stress may have something to worry about.
Women with autistic children who report chronic stress are more likely to have high levels of bad cholesterol and fewer cells that protect the vascular system from damage, putting them at higher risk for heart disease, according to a new study published in the journal Brain, Behavior and Immunity.
Researchers at the University of California San Francisco say they were surprised at the results of the study, which was focused on cardiovascular risk factors among relatively healthy mothers.
While all parents experience stress, the new study suggests those with autistic children, who are more likely to engage in behavior that is emotionally stressful for mothers, have more to worry about.
"Children with autism are more likely to engage in behaviors that can be emotionally stressful for mothers, like becoming unpredictably aggressive, biting or hurting themselves or expressing little affection," Dr. Kirstin Aschbacher, an assistant professor at UC San Francisco's Departmen of Psychiatry, said in a press release. "Even knowing the challenges these mothers face, we were surprised by the differences in cardiovascular risk."
For the study, the researchers recruited 68 healthy mothers, 31 of whom had children with autism, interviewing them about levels of stress and checking fasting blood samples for circulating hematopoietic progenitor cells, which repair damage in blood vessels and prevent the buildup of low-density lipoproteins, or bad cholesterol.
Among the women, 30 percent of those with autistic children had LDL levels above moderate health risk for heart disease, compared to 8 percent of mothers with neurotypical children. The mothers with autistic children also had lower levels of circulating progenitor cells, which the researchers link to higher LDL levels and higher risk for heart disease.
Although there are no guaranteed methods for lowering stress levels, the researchers say mothers who reported more positive family interactions over the course of a week had more progenitor cells, suggesting less stress can help the body repair itself.
Exactly how to lower stress, however, remains a mystery, the researchers say.
"It's clear that stress can contribute to chronic disease, but fixing stress is not as simple as taking a deep breath or an occasional yoga class," said Aschbacher, who was lead researcher on the study. "Our study shows that the damaging aspects of stress can happen in families in everyday life. We don't know enough about how to treat stress from a family systems perspective."