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(单词翻译:双击或拖选)
"These kids are at higher risk for the development of plaque1 in their arteries2 as time goes by." - Donald LaVan, MD
A new study has found that teenagers who are exposed to second-hand3 tobacco smoke are more likely to have changes to their blood vessels5 that could lead to heart disease later in life.
Researcher Katariina Kallio of the University of Turku in Finland says her study on teenagers extends previous research, which found cardiovascular damage in grown-ups who breathed in other peoples' smoke.
"We know previously6 that in adults there is that kind of association, but we didn't know that in adolescents," she said in a telephone interview. "So somehow it was a surprise that there is already in adolescents these kinds of changes."
Significant changes
Changes include thicker walls in the youngsters' blood vessels. American Heart Association spokesman Dr. Donald LaVan explains why that change in the arteries is significant.
"The blood vessel4 wall, when it becomes thickened and the lining7 is disturbed, is more sensitive to the effects of cholesterol8 deposition9. So therefore, these kids are at higher risk for the development of plaque in their arteries as time goes by."
Plaque inside the artery10 can restrict blood flow, and makes blood clots11 more likely. Blood clots can block an artery and cause a heart attack.
In their study, the researchers tested blood for cotinine, a chemical which is produced when nicotine12 is metabolized, so they got an objective measure of how much smoke the teenagers were exposed to. They also did ultrasound and other tests to measure blood vessel function and the thickness of the artery wall.
Dr. Kallio agrees with Dr. LaVan that the results support the recommendation that kids be kept away from tobacco smoke.
"Exposure to tobacco smoke is a risk factor for cardiac disease already in adolescents, and that's why this study supports that children and adolescents need smoke-free environments," said Kallio.
Although there is some evidence that artery damage caused by second-hand smoke in adults may be reversible, LaVan says it's unclear whether that's also true for adolescents.
"We think that they may be. We do know that people who are taken out of high tobacco smoke environments have a definite drop in developing coronary artery disease. There's been studies that show that in adults, that when they're taken away, it is a prevention."
The study was published in the journal "Circulation: Cardiovascular Quality and Outcomes," which is published by the American Heart Association.
1 plaque | |
n.饰板,匾,(医)血小板 | |
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2 arteries | |
n.动脉( artery的名词复数 );干线,要道 | |
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3 second-hand | |
adj.用过的,旧的,二手的 | |
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4 vessel | |
n.船舶;容器,器皿;管,导管,血管 | |
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5 vessels | |
n.血管( vessel的名词复数 );船;容器;(具有特殊品质或接受特殊品质的)人 | |
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6 previously | |
adv.以前,先前(地) | |
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7 lining | |
n.衬里,衬料 | |
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8 cholesterol | |
n.(U)胆固醇 | |
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9 deposition | |
n.免职,罢官;作证;沉淀;沉淀物 | |
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10 artery | |
n.干线,要道;动脉 | |
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11 clots | |
n.凝块( clot的名词复数 );血块;蠢人;傻瓜v.凝固( clot的第三人称单数 ) | |
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12 nicotine | |
n.(化)尼古丁,烟碱 | |
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13 undoing | |
n.毁灭的原因,祸根;破坏,毁灭 | |
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