Abstract: Objective To investigate the effects of ultraviolet radiation and age on elastic properties of the skin. Methods Cumulative sun exposure of 94 rural and 105 urban subjects in various age groups was assessed by means of a retrospective questionnaire. Elastic properties of the outer canthus, nasolabial fold, and infraorbital skin were measured with a cutometer. Results At the sites tested, almost all the elastic parameters of the skin(including elasticity, viscoelasticity, extensibility, and tonicity)were significantly decreased with age in both rural and urban groups(P<0.01).Meanwhile, in almost all age groups, there was a significant decrease of skin extensibility and tonicity in rural group compared with urban groups(P<0.01),Nevertheless, almost no significant difference was found in skin elasticity and viscoelasticity between the two groups. Conclusions The results suggest that the elastic parameters of the skin are significantly decreased with age. The decrease of skin elasticity and viscoelasticity may be mainly due to intrinsic aging, whereas photoaging may account for the reduction of skin extensibility and tonicity.

Key words: Ultraviolet rays, Skin aging, Skin elasticity, Cutometer, Photoaging