Secondhand Smoke Hurts the Heart
Even Low Exposures Make Big Impact
A Known Risk Factor continued...
Having low and high levels of cotinine was associated with a significant increase in two of the four heart disease markers, fibrinogen and homocysteine (fibrinogen is a blood clotting factor. Homocysteine is an amino acid and high levels have been linked to risk for heart, stroke, and blood vessel disease).
The association persisted even after the researchers controlled for other risk factors, including obesity, diet, physical activity level, and socioeconomic status.
No significant association was seen between secondhand smoke exposure and C-reactive protein or white blood cell count.
While the nicotine exposure levels seen in the exposed nonsmokers were far lower than those reported for active smokers, the apparent impact of secondhand smoke on heart disease risk was a third to half that associated with active smoking, Venn noted.
"Our study shows that very low levels of exposure to secondhand smoke may be associated with appreciable increases in cardiovascular risk," she says.
Researchers from the University of California San Francisco, came to a similar conclusion in a study presented at an American Heart Association meeting last spring.
James Lightwood, PhD, and colleagues concluded that eliminating secondhand smoke exposure would prevent more than 228,000 new cases of heart disease and 119,000 heart disease-related deaths by 2030.
The researchers developed a model to estimate the impact of secondhand smoke. They reported that 292,500 heart attacks could be prevented during the same period if exposure to secondhand smoke were eliminated.