Secondhand Smoke Boosts Fibrinogen, Homocysteine
Effect on cardiovascular biomarkers is one-third to one-half that seen in active smokers
MONDAY, Feb. 12 (HealthDay News) -- Even a low level of exposure to secondhand smoke increases cardiovascular disease biomarkers, such as fibrinogen and homocysteine, according to a report in the Feb. 12 issue of Circulation: Journal of the American Heart Association.
Andrea Venn, Ph.D., of the University of Nottingham in the U.K., and a colleague conducted a cross-sectional study of blood cotinine levels and cardiovascular biomarkers among 7,599 non-smoking adults from the Third National Health and Nutrition Examination Survey. Eighteen percent had no detectable cotinine and the remaining participants had either low or high levels. Of these, 18 percent with low levels and 56 with high levels of cotinine reported living with a smoker or occupational exposure to tobacco smoke.
Participants with high or low cotinine had fibrinogen levels that were 9 to 10 milligrams per deciliter of blood higher than those with no detectable cotinine and homocysteine levels that were 0.8 micromoles per liter of blood higher than their counterparts without detectable cotinine. No effect was seen on C-reactive protein and white blood cell count. Overall, the cotinine levels seen in the new study were about 0.1 percent of those in active smokers, but the effects on biomarkers were about one-third to one-half of those for active smoking.
"These findings lend support to existing evidence that secondhand smoke has a clinically important effect on susceptibility to cardiovascular disease," the researchers conclude.