First published: March 7, 2010
Source: SCMP via Reuters
Children as young as 13 who have evidence of second-hand smoke in their blood also have visibly thicker arteries, Finnish researchers have reported.
Their study suggests the damage caused by second-hand 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
adult blood vessels, 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, says.
Her team studied 494 children aged eight to 13 taking part in ongoing
research on heart disease. They measured levels of cotinine, a by-product
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.
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 reports in the journal Circulation:
Cardiovascular Quality and Outcomes. Their aortas were 8 per cent thicker.
The researchers also did a test that measured the flexibility of the
arteries in the arm, another measure of blood vessel health and heart
disease risk.
This measurement, called brachial artery flow-mediated dilation, was 15 per
cent lower in teenagers with the highest levels of cotinine, they found.
And measures of cholesterol showed unhealthier levels among the children
with more smoke in their blood.
“These findings suggest that children should not face exposure to tobacco
smoke at all,” Kallio says. “Even a little exposure to tobacco smoke may be
harmful for the blood vessels.”