Toddlers Affected Most by Secondhand Smoke Exposure

Secondhand smoke in the home appears to induce markers for heart disease as early as the toddler years, researchers reported at the American Heart Association's 48th Annual Conference on Cardiovascular Disease Epidemiology and Prevention.

It has long been known that many forms of cardiovascular disease in adults are initiated and progress silently during childhood. Now researchers have found a young child's response to smoke may not just affect the respiratory system, but the cardiovascular system as well.

"This is the first study that looks at the response of a young child's cardiovascular system to secondhand smoke," says Dr. Judith Groner, lead author of the study, pediatrician and ambulatory care physician at Nationwide Children's Hospital and Research Institute in Columbus, Ohio.

The study included 128 children, 2 to 5 years old and adolescents 9 to 14. Researchers found that children ages 2 to 5 absorbed six times more nicotine than children 9 to 14 from the same levels of parental smoking. That exposure resulted in a dramatic increase of markers of inflammation and vascular injury signaling damage to the endothelium, the inner lining of the vessel walls.

Hair samples of children ages 2 to 5 showed this age group had average nicotine levels of 12.68 nanograms per milligram of hair compared to the 9 to 14 year age group, which had 2.57 nanograms per milligram of hair. Toddlers had significantly higher levels of the inflammatory marker soluble intracellular adhesion molecules (ICAM).

"Toddlers in the homes of smokers not only had higher levels of nicotine, but also had higher levels of markers for cardiovascular disease in the blood," says Dr. John Bauer, senior author of the study and director of the Center for Cardiovascular Medicine at Nationwide Children's Hospital and Research Institute in Columbus, Ohio. "The dose of smoke is greater in toddlers than adolescents who are able to move in and out of the home. Toddlers are like a fish in a fishbowl. They are exposed at a higher dose. And it appears that toddlers also are more susceptible to the cardiovascular effects of smoke."

For more information, visit www.americanheart.org.