Decreased Subepithelial Microvasculature Observed by High Magnification Bronchovideoscope in the Large Airways of Smokers

• Published in: Internal Medicine Vol. 47; no. 18; pp. 1579 - 1583
• Main Authors: Yamada, Gen, Shijubo, Noriharu, Kitada, Junya, Takahashi, Mamoru, Otsuka, Mitsuo, Fujii, Masaru, Takahashi, Hiroki
• Format: Journal Article
• Language: English
• Published: Japan The Japanese Society of Internal Medicine 01.01.2008
• Subjects: Adult; Aged; Aged, 80 and over; Bronchi - blood supply; Bronchoscopy; cigarette smoker; Connexins; Eye Proteins; Female; Humans; Male; Microvessels - physiopathology; Middle Aged; Smoking - physiopathology; subepithelial microvessels; Trachea - blood supply
• ISSN: 0918-2918; 1349-7235
• DOI: 10.2169/internalmedicine.47.1205

Objective A fine vascular network is developed in the subepithelial layer of bronchial mucosa. Cigarette smoking is thought to influence angiogenesis. However, the bronchial microvasculature in smokers has not been fully investigated. The aim of this study was to determine the characteristics of the subepithelial microvessels in the large airways of smokers. Methods Between August 2000 and July 2004, 12 current smokers and 12 nonsmokers were enrolled in this study. The nonsmokers had no abnormal findings in the large airways in the examination of conventional bronchoscopy. Smoking histories varied from 20 to 50 years. The average smoking index was 31.3±19.9 (mean ± SD) pack-years. High magnification bronchovideoscopy was used in this study, which provides information on bronchial mucosa with a maximum magnification of 110 times. To evaluate the characteristics of subepithelial microvessels, 4 parameters were compared between the two groups: 1) vessel area ratio, 2) vessel length ratio, 3) vessel area to length ratio, and 4) hemoglobin index. Results Subepithelial microvessels of large airways were narrow and sparsely distributed in smokers. Vessel area ratio, vessel length ratio, vessel area to length ratio and hemoglobin index were significantly lower in the smokers than in the nonsmokers (p<0.0001, p<0.0001, p<0.0001, p=0.0002, respectively). Conclusion Subepithelial microvessels of smokers were decreased and narrow, which suggested a decrease in microcirculation in the subepithelial layer of the large airway.