title: Loss of skin elasticity precedes to rapid increase of wrinkle levels.
abstract: BACKGROUND
  Decreased skin elasticity is considered as a factor that promotes wrinkle formation. However, the relationship between decreased skin elasticity and the formation of wrinkles is not fully understood.
  
  
  OBJECTIVE
  The purpose of this study is to characterize the relationship between skin elasticity and wrinkle formation using quantitative methods.
  
  
  METHODS
  Skin elasticity at the corner of the eye was measured using a Cutometer SEM575. Wrinkle levels at the corner of the eye were determined from three-dimensional analysis of surface replicas. Ninety healthy female volunteers living in Tokyo, Japan (aged 18-76 years) were examined in this study.
  
  
  RESULTS
  In each scatter plot examined, women with lower U(r)/U(f) values or with higher U(v)/U(e) values showed a tendency for increased R(a) and R(max) values. However, this study determined widely scattered values for both types of parameters. These relationships were then reanalyzed in relation to age. Results were compared within a young (YNG) group of 27 women (aged 18-29), a middle-aged (MED) group of 26 women (aged 30-48) and an elderly (OLD) group of 37 women (aged 50-76). For elasticity parameters, U(r)/U(f) and U(v)/U(e) values, significant differences were found between the YNG and MED groups and also between the MED and OLD groups. For roughness parameters, a significant difference was found only between the MED and OLD groups. These results suggest that changes in R(a) or R(max) values lag about 20 years behind changes in skin elasticity values.
  
  
  CONCLUSIONS
  Despite a strong relationship, elasticity parameters are unlikely to be an independent predictor of wrinkle levels. The amount of UV exposure to skin with decreased elasticity seems to be the variable that determines wrinkle levels. This finding represents another complexity in the mechanism of wrinkle formation.
authors.affiliation: Biological Science Laboratories, Kao Corporation, 2606 Akabane, Ichikai-machi, Haga-gun, Tochigi 321-3497, Japan. Fujimura.tsutomu@kao.co.jp
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Fujimura
authors.forename: Keiichi
authors.initials: K
authors.lastname: Haketa
authors.forename: Mitsuyuki
authors.initials: M
authors.lastname: Hotta
authors.forename: Takashi
authors.initials: T
authors.lastname: Kitahara
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D004548:Elasticity; D005123:Eye; D005260:Female; D006801:Humans; D008875:Middle Aged; D015233:Models, Statistical; D012044:Regression Analysis; D012867:Skin / Q000378:metabolism* / Q000473:pathology* / Q000528:radiation effects; D015595:Skin Aging; D014466:Ultraviolet Rays