Pilot study on the correlation between skin auto‐fluorescence and serum antioxidant enzyme: skin auto‐fluorescence is negatively associated with levels of malondialdehyde

Background/purpose Various methods have been used to objectively record skin changes. However, estimating the intrinsic and extrinsic aging of skin remains a challenge. Our objective was to study intrinsic skin aging with respect to patient age and extrinsic photo‐aging of human dorsal (photo‐exposed) and volar (photo‐protected) forearm in vivo through skin auto‐fluorescence (AF). We also examined the correlations between serum antioxidant enzyme, malondialdehyde(MDA), and skin AF. Methods 37 healthy volunteers were enrolled. We measured skin AF and its heterogeneity on the dorsal and volar forearms. We also examined serum concentration of catalase, superoxide dismutase, vitamin E, and MDA levels in every participant. Results In photo‐protected areas, skin AF intensity in the 40 years or older group was significantly higher compared to the group less than 40 years‐old. On the other hand, heterogeneity value was significantly higher in the less than 40 years‐old group in photo‐protected area. With respect to serum antioxidant enzyme and MDA level, only MDA level showed a negative correlation with skin AF intensity in photo‐exposed area. Conclusion We determined that skin AF intensity of the photo‐protected area reflects intrinsic skin aging. In addition, degree of photo‐aging could be indirectly inferred by skin AF of photo‐exposed area and serum MDA level.