University of Virginia Health System

Kids Suffer Early On from Secondhand Smoke

Secondhand smoke causes signs of cardiovascular damage in children, especially the very youngest, say researchers at an American Heart Association (AHA) meeting.

The youngest children appeared to be more affected than teens.

"Toddlers are smokers by default," says one of the study's authors, John Bauer, Ph.D., of Nationwide Children's Hospital and Research Institute.

"Forty percent of toddlers in our study had nicotine content that in adults would suggest that they were active smokers," he says. "But, an active smoker has a filter on cigarettes. The toxicity from smoke that is inhaled in the atmosphere is worse because there's no filter."

"These results do not surprise me," says Karen Rheuban, M.D., Professor of Pediatrics at the University of Virginia Health System. "Smoking and passive smoking by exposure to secondhand smoke causes a host of problems - including cardiovascular disease, cancer and asthma and chronic lung disease."

Toddlers Live in a Smoking "Fishbowl"

Bauer and his colleagues took hair and blood samples from 125 children. Fifty-seven were between ages 2 and 5; 68 were between ages 9 and 14.

Hair samples were used to measure nicotine exposure, and blood samples were used to look for a type of cell called an endothelial progenitor cell (EPC). These cells replenish the endothelium (the lining of the blood vessels) and provide clues to cardiovascular health levels.

The researchers also asked the parents how many smokers children had been exposed to in a 24-hour period.

Children in the youngest age group had almost six times the average nicotine levels than older children did.

Toddlers had an average nicotine level of 12.68 nanograms per milligram of hair, while older kids had an average level of 2.57 nanograms per milligram.

"Toddlers are like fish in a fish bowl," notes Bauer. "They're strapped pretty closely to their parental units, which exposes them to more smoke than adolescents who live in the same set of circumstances."

"Toddlers also breathe more rapidly, so they inhale more," adds co-author Dr. Judith Groner, a pediatrician.

The youngest children also had higher levels of an inflammatory marker called soluble intracellular adhesion molecules. There was an inverse relationship between EPC levels and exposure to smoke in both age groups, though the effect of secondhand smoke was more pronounced in the younger children.

These findings are similar to what has been found in adult smokers, according to the study authors. EPC levels have not yet been studied in adults exposed to secondhand smoke.

"Based on markers of vascular stress, toddlers are hit harder," explains Bauer. "To what extent this is reversible if exposure is stopped isn't known. In adults, there is evidence that when active smokers quit smoking, the risk of heart disease is lower, but some research suggests that cardiovascular disease may be imprinted in early life, so we don't know if this is reversible or not."

Quit Smoking or Go Outside to Smoke

"This study gives us more insight into the bad effects of secondhand smoke exposure from a respiratory and cardiac standpoint," says Dr. Devang Doshi, director of pediatric pulmonology, allergy and immunology at Beaumont Hospital. "A lot of people don't realize that when you smoke in the house, children are continuously exposed. It's always in the house; the smoke doesn't just go away."

Doshi says his first advice to parents is to quit smoking. Failing that, he advises parents to go outside and away from the house to smoke, and to wear at least two layers of clothing.

When they come back in the house, he recommends removing the top layer of clothing and washing their hands to try to limit their child's exposure.

"Children should be protected from such exposures, and the best protection is to completely avoid smoking in their presence," says UVA's Rheuban. "In addition, parents should consider the impact they have on their children as role models, and they themselves should make every effort to stop smoking."

For more information on secondhand smoke and other children's health issues, visit www.uvachildrenshospital.com.

Always consult your physician for more information.