Children exposed to their parents’ smoking may have a higher risk of developing heart disease in adulthood than those whose parents did not smoke, according to a study published March 23 online in Circulation.


Lead author Costan Magnussen, PhD, and colleagues tracked children in Finland exposed to parental smoking in 1980 and 1983. They collected carotid ultrasound data on these children in adulthood in 2001 and 2007. In 2014, the researchers measured cotinine levels, a biomarker of passive smoke exposure, in blood samples that were collected and frozen in 1980 when the participants were children. 


The percentage of children with undetectable cotinine levels was highest among households in which neither parent smoked (84%), lower in households in which one parent smoked (62%), and lowest in households in which both parents smoked (43%).

The authors determined that the risk of developing carotid plaque in adulthood was 1.7 times higher in children exposed to one or two parental smokers, compared with children of parents who did not smoke. In addition, the risk was elevated even if parents who smoked tried to limit their children’s exposure: In children whose parents tried to limit their children’s exposure, the risk was 1.6 times higher, and in children whose parents did not seem to limit their children’s exposure, the risk was four times higher.