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

Tobacco smoking is an important risk factor for multiple major diseases including cancer and stroke. It is of significance to search for the biomarkers of smoking for non-invasive, rapid and economic monitoring of the pathological changes of smokers’ body. However, there has been no non-invasive method for monitoring the health state of smokers. Our current study has indicated that green autofluorescence (AF) of the fingernails and certain locations of the skin is a novel biomarker for smoking: 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, the population at-risk of developing stroke and the acute ischemic stroke (AIS) patients. ROC analyses using the green AF intensity of either right or left Index Fingernails showed that the AUC values ranged from 0.8136 and 0.8644 for differentiating smokers and non-smokers in these populations. ROC analyses using the green AF intensity of the skin of the right Dorsal Index Fingers showed that the AUC values ranged between 0.7418 and 0.7478 for differentiating the smokers and the non-smokers in natural populations and the population at-risk of developing stroke. Collectively, our study has indicated that increased green AF intensity of the fingernails and certain locations of the skin is a novel biomarker for smoking. Based on this finding, pathological alterations of smokers’ body may be monitored non-invasively, rapidly and economically, which could be highly valuable for the health management of the large population of tobacco smokers.