ORLANDO, Florida (Reuters) - Toddlers and obese children suffer far greater blood-vessel damage and other harm from secondhand smoke than other children, which could put them on the path to heart disease later in life, according to a new study.
The study, presented at the American Heart Association scientific meeting in Orlando on Wednesday, found a link between the amount of secondhand smoke exposure and a marker of vascular injury in toddlers, defined as children ages 2 to 5. The link was twice as great in toddlers who were obese, researchers said.
"We think that the two factors together -- smoke exposure plus obesity -- may interact to amplify the degree of inflammation or vascular cell damage that occurs," said John Bauer, the study's co-lead investigator from Nationwide Children's Hospital & Research Institute at Ohio State University.
The study of American boys and girls exposed to smokers included 52 toddlers and 107 older children ages 9 to 18.
It found toddlers had a four times greater risk of secondhand smoke exposure when compared with adolescents, despite having similar reported home exposures.
This may be because toddlers tend to be in closer proximity to their smoking parents for extended periods of time.
"Adolescents are less joined at the hip to their parents. Toddlers don't have the same access to move in and out of the house," Bauer said.
Toddlers exposed to secondhand smoke were also found to have a 30 percent reduction in circulating vascular endothelial progenitor cells, a type of cell involved in the repair and maintenance of a healthy blood vessel network, researchers said.
"The changes we detected in these groups of children are similar to changes that are well recognized risks for heart disease in adults," Bauer said.
"This suggests that some aspects of adult heart disease may be initiated in early childhood, where prevention strategies may have great long-term impact," Bauer said.
At least a quarter of children in the United States are exposed to secondhand smoke, researchers said.
Bauer said the study did not differentiate between smoke exposure at home and while in a car, which Bauer called "a real fish in a fish bowl experience."
Reporting by Bill Berkrot and Ransdell Pierson, editing by Gerald E. McCormick