Morphologic changes in the microcirculation induced by chronic smoking habit: a videocapillaroscopic study on the human labial mucosa.

BACKGROUND: Cigarette smoking has been identified as a major risk factor for cardiovascular and pulmonary diseases. Although an impressive literature does exist on the subject, no evidence is available on morphologic changes induced with chronic smoking habit in the human microcirculation. SUBJECTS AND METHODS: One hundred healthy subjects, 50 smokers and 50 nonsmokers, underwent videocapillaroscopy of the labial mucosa. For each subject, the caliber of capillary loops, the number of visible capillary loops, the background optical transmittance, the tortuousness of capillary loops, the presence of microaneurysms, the presence of microhemorrhages, and the cumulative smoking habit (pack-year index) were noted. RESULTS: Smokers had a lower caliber of capillary loops (P <.001), with a higher number of visible capillary loops (P <.001), a lower background optical transmittance (P <.001), and a more marked tortuousness of capillary loops (P <.001). Microaneurysms and microhemorrhages were absent in nonsmokers, and 1 smoker of 3 had microaneurysms alone, and 1 smoker of 3 had both microaneurysms and microhemorrhages. A significant correlation was found between cumulative smoking habit and tortuousness of capillary loops (P <.001) and between cumulative smoking habit and total score (tortuousness score + microaneurysm score + microhemorrhage score; P <.005). CONCLUSION: Chronic smoking habit does induce significant morphologic changes in the microcirculation of the human labial mucosa, and these changes can be easily and comfortably recorded with videocapillaroscopy.