Secondhand smoke damages arteries in teens

Children as young as 13 who have evidence of secondhand smoke in their blood also have visibly thicker arteries, Finnish researchers reported on Tuesday.

Their study suggests that the damage caused by secondhand tobacco smoke starts in childhood and causes measurable damage by the teen years.

"Although previous research has found that passive smoke may be harmful for blood vessels among adults, we did not know until this study that these specific effects also happen among children and adolescents," Dr. Katariina Kallio of the University of Turku in Finland, who led the study, said in a statement.

Her team studied 494 children aged 8 to 13 taking part in ongoing research on heart disease. They measured levels of cotinine, a byproduct of nicotine that is found in the blood after someone breathes in tobacco smoke.

They divided the children into groups with high, intermediate and low cotinine levels. Ultrasound was used to measure the thickness of the aorta and of the carotid artery in the neck.

Artery walls look thicker on an ultrasound if they are damaged by the process of atherosclerosis.

The children with the most cotinine in their blood had carotid artery walls that were, on average, 7 per cent thicker than the children with the lowest cotinine levels, Kallio's team reported in the journal Circulation: Cardiovascular Quality and Outcomes. Their aortas were 8 per cent thicker.