title: Skin biophysical properties of a population living in Valais, Switzerland.
abstract: OBJECTIVE
  Switzerland has one of the highest rates of skin diseases and particularly skin cancer, in Europe. Skin elastosis, roughness and atopy are also frequent. High UV exposure and prevalence of light skin individuals could be the cause. Valais, in Southern Switzerland, is a mountain region with elevated sun irradiation and low air humidity, an ideal location to study the effect of the environment and life style on skin biophysical characteristics. The purpose of the study was to measure skin biophysical parameters non-invasively on healthy subjects living in Valais, and to correlate the measures with their life style.
  
  
  METHODS
  One hundred and ten women were examined between October 2001 and February 2002. Measures of skin hydration, sebum content, pH and visco-elasticity were taken in a closed environment with constant temperature and controlled air humidity, utilizing commercially available non-invasive devices. Subjects were interviewed using a questionnaire and data on personal traits and life style were collected. Correlations between subject's skin parameters and life style were statistically examined.
  
  
  RESULTS
  On average we observed low values of skin capacitance that identify subjects with dry skin. Measures of skin visco-elasticity ratios were also particularly low, while skin pH and sebum content were in the normal range. Age was correlated with a decrease of skin elasticity and sebum content, but there was no correlation with hydration or pH.
  
  
  CONCLUSIONS
  We confirm, as reported in other studies, the effect of age on skin elasticity and sebum content and we identify, for the first time, a region with a population characterized by particularly low levels of skin hydration and skin visco-elasticity. Although people examined were free of skin diseases, we believe that protection from the sun and treatment of skin with hydrating products need to be emphasized as a prevention strategy, in regions such as Valais, with high sun irradiation and low humidity.
authors.affiliation: Laboratoires Biologiques Arval S.A., Conthey, Switzerland.
authors.forename: Pierre-André
authors.initials: PA
authors.lastname: Wendling
authors.forename: Giorgio
authors.initials: G
authors.lastname: Dell'Acqua
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008019:Life Style; D008875:Middle Aged; D012016:Reference Values; D012629:Sebum / Q000378:metabolism; D012867:Skin / Q000528:radiation effects; D012879:Skin Physiological Phenomena; D013557:Switzerland / Q000453:epidemiology; D014466:Ultraviolet Rays