Smoking is associated with significantly increased green autofluorescence intensity and asymmetry of the skin and the fingernails of natural populations, population at-risk of developing stroke, and population of acute ischemic stroke

Our previous studies have suggested that the Pattern of Autofluorescence (AF) of the skin and fingernails is a novel biomarker for non-invasive diagnosis of several major diseases. In order to improve this new technology, it is critical to further investigate the factors that can influence the AF in natural populations, populations at-risk of developing major diseases and patient populations. Our current study found that both the green AF intensity and the AF asymmetry of the fingernails and the skin of Dorsal Index Fingers of the smokers were significantly higher than those of the non-smokers in natural populations and the population at-risk of developing stroke. In the population of acute ischemic stroke patients, the green AF intensity of the fingernails and the skin of Dorsal Index Fingers, Ventroforefingers and Centremetacarpus of the smokers was significantly higher than that of the non-smokers. In both fingernails and Dorsal Index Fingers, the AF intensity of the male persons was also significantly higher than that of the female persons, while the AF intensity of the male non-smokers was similar with that of female non-smokers. Collectively, our study has indicated that smoking is an important factor associated with significantly increased AF intensity and AF asymmetry of the fingernails and certain positions of the skin in these populations, which is critical for understanding the mechanisms underlying the changes of the AF in these populations. Our study has also indicated smoking as a key factor for gender differences in the AF intensity at fingernails and Dorsal Index Fingers.