Smoking is associated with lower amounts of arterial type I collagen and decorin

Smoking affects the arterial wall and increases the risk of cardiovascular disease. It also affects the extracellular matrix in skin, causing impaired wound healing. However, little is known about putative molecular changes in the arterial wall. Our aim was to investigate the possible correlation between extracellular matrix content in arterial tissue and cigarette smoking.

We studied the non-atherosclerotic arterial wall of the internal mammary artery from coronary artery by-pass surgery in 13 never-smokers and 11 active smokers. Using histomorphometric methods, the area fraction of collagen stainable material was determined. In addition, proteome analysis of matrix molecules and other proteins was performed.

The area fraction of collagen stainable material in smokers vs. never-smokers was 29.1% ± 3.8% vs. 43.3% ± 3.6% (mean ± SEM, p = 0.012) in tunica intima, 39.7% ± 5.5% vs. 56.8% ± 5.6% (mean ± SEM, p = 0.042) in tunica media, and 50.4% ± 3.9% vs. 61.0% ± 3.2% (mean ± SEM, p = 0.046) in tunica adventitia. We discovered significantly lower relative levels of collagen α1(I) (0.68 ± 0.048 vs. 1.02 ± 0.112, mean ± SEM, p = 0.013), collagen α2(I) (0.81 ± 0.046 vs. 1.14 ± 0.118, mean ± SEM, p = 0.038) and decorin (0.64 ± 0.04 vs. 0.98 ± 0.11, mean ± SEM, p = 0.009) in smokers.

Arterial tissue from active smokers contains decreased amounts of collagen stainable material, as well as type 1 collagen and decorin. These findings may explain some effects of smoking on the development of cardiovascular disease including compromised remodelling and increased risk of aneurysms.