Friday, July 27, 2007

Exhausted arteries

My mom lives in a condominium complex with a beautifully landscaped central area, complete with pond. As you walk the grounds, a background roar suggests the wind or sea but is, in fact, the traffic noise of I-25 just behind the high wall surrounding the complex. Out of sight may be out of mind, but the arteries within may never forget that highway nearby.

German researchers studied nearly 5,000 subjects living in the industrialized Ruhr area(1). The participants underwent electron-beam computed tomography or heart CT scans to determine their degree of coronary artery calcification (CAC) which indicates the level of cholesterol build-up in arteries. The investigators found a significant correlation between CAC scores and the proximity of the nearest highway to the subjects' homes.

Immunologists at UCLA determined the underlying mechanism of this relationship between urban air pollution and risk of heart disease(2). In both human artery tissue samples and in mice, these California docs determined that diesel particles plus LDL-cholesterol leads to more severe atherosclerosis than either soot or cholesterol alone. Both arterial irritants cause the release of 'free radicals' or reactive oxygen molecules known to be highly damaging to human tissue.

My guess is that the summer air here in Denver that hangs visibly through the trees on a hot summer day is the equivalent of living next to I-25 with respect to our heart's health.
1. Hoffmann B et al. Residential Exposure to Traffic Is Associated With Coronary Atherosclerosis Circulation. 2007;0: CIRCULATIONAHA.107.693622
2. Nel a et al. The cellular impacts of diesel exhaust particles: beyond inflammation and death. Eur Respir J. 2006 Apr;27(4):667-8.

1 comment:

Mauigirl said...

Very interesting. I guess living in New Jersey isn't too good for one's health either!